14-What Do Analytical Chemists Do
化学化工专业英语
1 CHEMISTRY AND CHEMISTWithout chemistry our lives would beunrecognisable, for chemistry is at work all aroundus. Think what life would be like without chemistry- there would be no plastics, no electricity and noprotective paints for our homes. There would be no synthetic fibres to clothe us and no fertilisers to help us produce enough food. We wouldn‟t be able to travel because there would be no metal, rubber or fuel for cars, ships and aeroplane. Our lives would be changed considerably without telephones, radio, television or computers, all of which depend on chemistry for the manufacture of their parts. Life expectancy would be much lower, too, as there would be no drugs to fight disease.Chemistry is at the forefront of scientific adventure, and you could make your own contribution to the rapidly expanding technology we are enjoying. Take some of the recent academic research: computer graphics allow us to predict whether small molecules will fit into or react with larger ones - this could lead to a whole new generation of drugs to control disease; chemists are also studying the use of chemicals to trap the sun‟s energy and to purify sea water; they are also investigating the possibility of using new ceramic materials to replace metals which can corrode.Biotechnology is helping us to develop new sources of food and new ways of producing fuel, as well as producing new remedies for the sick. As the computer helps us to predict and interpret results from the test tube, the speed, accuracy and quality of results is rapidly increasing - all to the benefit of product development.It is the job of chemists to provide us with new materials to take us into the next century, and by pursuing the subject, you could make your positive contribution to society.Here are some good reasons for choosing chemistry as a career.Firstly, if you have an interest in the chemical sciences, you can probably imagine taking some responsibility for the development of new technology. New ideas and materials are constantly being used in technology to improve the society in which we live. You could work in a field where research and innovation are of primary importance to standards of living, so you could see the practical results of your work in every day use.Secondly, chemistry offers many career opportunities, whether working in a public service such as a water treatment plant, or high level research and development in industry. Your chemistry-based skills and experience can be used, not only in many different areas within the chemical industry, but also as the basis for a more general career in business.1 As a qualification, chemistry is highly regarded as a sound basis for employment.You should remember that, as the society we live in becomes more technically advanced, the need for suitably qualified chemists will also increase. Although chemistry stands as a subject in its own right, it acts as the bond between physics and biology. Thus, by entering the world of chemistry you will be equipping yourself to play a leading role in the complex world of tomorrow.Chemistry gives you an excellent training for many jobs, both scientific and non-scientific. To be successful in the subject you need to be able to think logically, and be creative, numerate, and analytical. These skills are much sought after in many walks of life, and would enable you to pursue a career in, say, computing and finance, as well as careers which use your chemistry directly.Here is a brief outline of some of the fields chemists work in:Many are employed in the wealth-creating manufacturing industries - not just oil, chemical and mining companies, but also in ceramics, electronics and fibres. Many others are in consumer based industries such as food, paper and brewing; or in service industriessuch as transport, health and water treatment.In manufacturing and service industries, chemists work in Research and Development to improve and develop new products, or in Quality Control, where they make sure that the public receives products of a consistently high standard.Chemists in the public sector deal with matters of public concern such as food preservation, pollution control, defence, and nuclear energy. The National Health Service also needs chemists, as do the teaching profess ion and the Government‟s research and advisory establishments.Nowadays, chemists are also found in such diverse areas as finance, law and politics, retailing, computing and purchasing. Chemists make good managers, and they can put their specialist knowledge to work as consultants or technical authors. Agricultural scientist, conservationist, doctor, geologist, meteorologist, pharmacist, vet ... the list of jobs where a qualification in chemistry is considered essential is endless. So even if you are unsure about what career you want to follow eventually, you can still study chemistry and know that you‟re keeping your options open.What Do Chemistry Graduates Do?Demand for chemists is high, and over the last decade opportunities for chemistry graduates have been increasing. This is a trend that is likely to continue. Chemistry graduates are increasingly sought after to work in pharmaceutical, oil, chemical, engineering, textile and metal companies, but the range of opportunities also spans the food industry, nuclear fuels, glass and ceramics, optical and photographic industries, hospitals and the automotive industry. Many graduates begin in scientific research, development and design, but over the years, about half change, into fields such as sales, quality control, management, or consultancy. Within the commercial world it is recognised that, because of the general training implicit in a chemistry course, chemistry graduates are particularly adaptable and analytical - making them attractive to a very broad spectrum of employers. There has been a growth of opportunity for good chemistry graduates to move into the financial world, particularly in accountancy, retail stores, and computer software houses.（Summarized from: A brief of the Royal Society of Chemistry,1992）2 NOMENCLATURE OF INORGANICCOMPOUNDSNaming elementsThe term element refers to a pure substance with atoms all of a single kind. At present 107 chemical elements are known. For most elements the symbol is simply the abbreviated form of the English name consisting of one or two letters, for example:oxygen = O nitrogen = N magnesium = MgSome elements, which have been known for a long time, have symbols based on their Latin names, for example:iron = Fe (ferrum) copper = Cu (cuprum) lead = Pb (Plumbum)A few elements have symbols based on the Latin name of one of their compounds, the elements themselves having been discovered only in relatively recent times1, for example: sodium = Na (natrium = sodium carbonate)potassium = K (kalium = potassium carbonate)A listing of some common elements may be found in Table 1.Naming Metal Oxides, Bases and SaltsA compound is a combination of positive and negative ions in the proper ratio to give a balanced charge and the name of the compound follows from names of the ions, for example, NaCl, is sodium chloride; Al(OH)3is aluminium hydroxide; FeBr2is iron (II) bromide or ferrous bromide; Ca(OAc)2is calcium acetate; Cr2(SO4)3is chromium (III) sulphate or chromic sulphate, and so on. Table 3 gives some examples of the naming of metal compounds. The name of the negative ion will need to be obtained from Table 2.Negative ions, anions, may be monatomic or polyatomic. All monatomic anions have names ending with -ide. Two polyatomic anions which also have names ending with -ide are the hydroxide ion, OH-, and the cyanide ion, CN-.Many polyatomic anions contain oxygen in addition to another element. The number of oxygen atoms in such oxyanions is denoted by the use of the suffixes -ite and -ate, meaning fewer and more oxygen atoms, respectively. In cases where it is necessary to denote more than two oxyanions of the same element, the prefixes hypo- and per-, meaning still fewer and still more oxygen atoms, respectively, may be used, for example,hypochlorite ClO-Chlorite ClO2-chlorate ClO3-perchlorate ClO4-Naming Nonmetal OxidesThe older system of naming and one still widely used employs Greek prefixes for both the number of oxygen atoms and that of the other element in the compound 2. The prefixes used are (1) mono-, sometimes reduced to mon-, (2) di-, (3) tri-, (4) tetra-, (5) penta-, (6) hexa-, (7) hepta-, (8) octa-, (9) nona- and (10) deca-. Generally the letter a is omitted from the prefix (from tetra on ) when naming a nonmetal oxide and often mono- is omitted from the name altogether.The Stock system is also used with nonmetal oxides. Here the Roman numeral refers to the oxidation state of the element other than oxygen.In either system, the element other than oxygen is named first, the full name being used, followed by oxide 3. Table 4 shows some examples.Naming AcidsAcid names may be obtained directly from a knowledge of Table 2 by changing the name of the acid ion (the negative ion ) in the Table 2 as follows:The Ion in Table 2Corresponding Acid-ate-ic-ite-ous-ide-icExamples are:Acid Ion Acidacetate acetic acidperchlorate perchloric acidbromide hydrobromic acidcyanide hydrocyanic acidThere are a few cases where the name of the acid is changed slightly from that of the acid radical; for example, H2SO4 is sulphuric acid rather than sulphic acid. Similarly, H3PO4 is phosphoric acid rather than phosphic acid.Naming Acid and Basic Salt and Mixed SaltsA salt containing acidic hydrogen is termed an acid salt.A way of naming these salts is to call Na 2HPO4disodiumhydrogen phosphate and NaH2PO4sodium dihydrogenphosphate. Historically, the prefix bi- has been used innaming some acid salts; in industry, for example, NaHCO3 iscalled sodium bicarbonate and Ca(HSO3)2 calcium bisulphite.Bi(OH)2NO3, a basic salt, would be called bismuthdihydroxynitrate. NaKSO4, a mixed salt, would be calledsodium potassium sulphate.3 NOMENCLATURE OF ORGANIC COMPOUNDSA complete discussion of definitive rules of organic nomenclature would require more space than can be allotted in this text. We will survey some of the more common nomenclature rules, both IUPAC and trivial.AlkanesThe names for the first twenty continuous-chain alkanes are listed in Table 1.Alkenes and AlkynesUnbranched hydrocarbons having one double bond are named in the IUPAC system by replacing the ending -ane of the alkane name with -ene. If there are two or more double bonds, the ending is -adiene, -atriene, etc.Unbranched hydrocarbons having one triple bond are named by replacing the ending -ane of the alkane name with -yne. If there are two or more triple bonds, the ending is -adiyne, -atriyne etc. Table 2 shows names for some alkyl groups, alkanes, alkenes and alkynes.The PrefixesIn the IUPAC system, alkyl and aryl substituents and many functional groups are named as prefixes on the parent (for example, iodomethane). Some common functional groups named as prefixes are listed in Table 3.In simple compounds, the prefixes di-, tri-, tetra-, penta-, hexa-, etc. are used to indicate the number of times a substituent is found in the structure: e.g., dimethylamine for(CH3)2NH or dichloromethane for CH2Cl2.In complex structures, the prefixes bis-, tris-, and tetrakis- are used: bis- means two of a kind; tris-, three of a kind; and tetrakis-, four of a kind. [(CH3)2N]2is bis(dimethylamino) and not di(dimethylamino).Nomenclature Priority of Functional GroupsIn naming a compound, the longest chain containing principal functional group is considered the parent. The parent is numbered from the principal functional group to the other end, the direction being chosen to give the lowest numbers to the substituents. The entire name of the structure is then composed of (1) the numbers of the positions of the substituts (and of the principal functional group, if necessary); (2) the names of the substituts;(3) the name of the parent.The various functional groups are ranked in priority as to which receives the suffix name and the lowest position number1.A list of these priorities is given in Table 4.*-CKetonesIn the systematic names for ketones, the -e of the parent alkane name is dropped and -one is added. A prefix number is used if necessary.In a complex structure, a ketone group my be named in IUPAC system with the prefix oxo-. (The prefix keto- is also sometimes encountered.)AlcoholsThe names of alcohols may be: (1) IUPAC; (2) trivial; or, occasionally, (3) conjunctive. IUPAC names are taken from the name of the alkane with the final -e changed to -ol. In the case of polyols, the prefix di-, tri- etc. is placed just before -ol, with the position numbers placed at the start of the name, if possible, such as, 1,4-cyclohexandiol. Names for some alkyl halides, ketones and alcohols are listed in Table 5.EthersEthers are usually named by using the names of attached alkyl or aryl groups followed by the word ether. (These are trivial names.) For example, diethyl ether.In more complex ethers, an alkoxy- prefix may be used. This is the IUPAC preference, such as 3-methoxyhexane. Sometimes the prefix- oxa- is used.AminesAmines are named in two principal ways: with -amine as the ending and with amino- as a prefix. Names for some ethers and amines can be found in Table 6.Carboxylic AcidsThere are four principal types of names for carboxylic acids: (1) IUPAC; (2)trivial;(3)carboxylic acid; and (4)conjunctive. Trivial names are commonly used.AldehydesAldehydes may be named by the IUPAC system or by trivial aldehyde names. In the IUPAC system, the -oic acid ending of the corresponding carboxylic acid is changed to -al, such as hexanal. In trivial names, the -ic or -oic ending is changed to -aldehyde, such as benzaldehyde. Table 7 gives a list of commonly encountered names for carboxylic acids and aldehydes.Esters and Salts of Carboxylic AcidsEsters and salts of carboxylic acids are named as two words in both systematic and trivial names. The first word of the name is the name of the substituent on the oxygen. The second word of the name is derived from the name of the parent carboxylic acid with the ending changed from -ic acid to -ate.AmidesIn both the IUPAC and trivial systems, an amide is named by dropping the -ic or -oic ending of the corresponding acid name and adding -amide, such as hexanamide (IUPAC) and acetamide (trivial).Acid AnhydridesAcid anhydrides are named from the names of the component acid or acids with the word acid dropped and the word anhydride added, such as benzoic anhydride.The names for some esters, amides and anhydrides are shown in Table 8.Acid HalidesAcid halides are named by changing the ending of the carboxylic acid name from -ic acid to -yl plus the name of the halide, such as acetyl chloride.Some names of aryl compounds and aryls are as follows:benzenephenylbenzylarylbenzoic acid4. Introduction to Chemistry Department of FloridaUniversityProgram of StudyThe Department of Chemistry offers programs of study leading to the M.S. and Ph.D. degrees. Students may elect studies in analytical, inorganic, organic, and physical chemistry. Specialty disciplines, such as chemical physics and quantum, bioorganic, polymer, radiation, and nuclear chemistry, are available within the four major areas.The M.S. and Ph.D. degree requirements include a course of study, attendance at and presentation of a series of seminars, and completion and defense of a research topic worthy of publication1. Candidates for the Ph.D. degree must also demonstrate a reading ability of at least one foreign language and show satisfactory performance on a qualifying examination. The M.S. degree is not a prerequisite for the Ph.D. degree. A nonthesisdegree program leading to the M.S.T. degree is offered for teachers.Students are encouraged to begin their research shortly afterselecting a research director, who is the chairman of the supervisory committee that guides the student through a graduate career.Research FacilitiesThe chemistry department occupies 111,000 square feet of space in four buildings: Leigh Hall, the Chemical Research Building, Bryant Hall, and the Nuclear Science Building. Plans for a 65,000-square-foot addition to Leigh Hall are being prepared. A new central science library is located near the chemistry facilities. The University library system holds more than 2.2 million volumes.The major instrumentation includes ultraviolet-visible, infrared, fluorescence, Roman, nuclear magnetic resonance, electron spin resonance, X-ray, ESCA, and mass spectrometers. Many are equipped with temperature-control and Fourier-transform attachments, and some have laser sources. Data-storage and data-acquiring minicomputers are interfaced to some of the instruments, such as the recently constructed quadrupole resonance mass spectrometer. The chemistry department has V AX-11/780 and V AX-11/750 computers as well as multiple terminals connected to IBM machines in the main computer centre on campus.The departmental technical services include two well-equipped stockrooms and glassblowing, electronics, and machine shops to assist in equipment design, fabrication, and maintenance.Financial AidMost graduate students are given financial support in the form of teachingand research assistantships. Stipends range from $9400 - 11,000 for the1986-87 calendar year. State residents and assistantship holders pay in-statefees of about $1400 per calendar year. A limited number of full orsupplemental fellowships are available for superior candidates.Cost of StudyIn 1985-86, in-state students paid a registration fee of $48.62, per credit hour for each semester, out-of-state students paid an additional $ 94.50 ($ 143.12 per credit hour each semester). A small increase in fees is expected for 1986-87.5 ENVIRONMENTAL POLLUTIONWith the coming of the Industrial Revolution the environmentalpollution increased alarmingly. Pollution can be defined as an undesirablechange in the physical, chemical, or biological characteristics of the air, water,or land that can harmfully affect health, survival, or activities of humans orother living organisms. There are four major forms of pollution - waste onland, water pollution (both the sea and inland waters), pollution of the atmosphere and pollution by noise.Land can be polluted by many materials. There are two major types of pollutants: degradable and nondegradable. Examples of degradable pollutantsare DDT and radioactive materials. DDT can decompose slowly buteventually are either broken down completely or reduced to harmless levels. For example, it typically takes about 4 years for DDT in soil to be decomposed to 25 percent of the original level applied. Some radioactive materials that give off harmful radiation, such as iodine-131, decay to harmless pollutants. Others, such as plutonium-239 produced by nuclear power plants, remains at harmful levels for thousands to hundreds of thousands of years.Nondegradable pollutants are not broken down by natural processes. Examples ofnondegradable pollutants are mercury, lead and some of their compounds and some plastics. Nondegradable pollutants must be either prevented from entering the air, water, and soil or kept below harmful levels by removal from the environment.Water pollution is found in many forms. It is contamination of water with city sewage and factory wastes; the runoff of fertiliser and manure from farms and feed lots; sudsy streams; sediment washed from the land as a result of storms, farming, construction and mining; radioactive discharge from nuclear power plants; heated water from power and industrial plants; plastic globules floating in the world‟s oceans; and female sex hormones entering water supplies through the urine of women taking birth control pills.Even though scientists have developed highly sensitive measuringinstruments, determining water quality is very difficult. There are a largenumber of interacting chemicals in water, many of them only in trace amounts.About 30,000 chemicals are now in commercial production, and each yearabout 1,000 new chemicals are added. Sooner or later most chemicals end up in rivers, lakes, and oceans. In addition, different organisms have different ranges of tolerance and threshold levels for various pollutants. To complicate matters even further, while some pollutants are either diluted to harmless levels in water or broken down to harmless forms by decomposers and natural processes, others (such as DDT, some radioactive materials, and some mercury compounds) are biologically concentrated in various organisms1.Air pollution is normally defined as air that contains one or more chemicals in high enough concentrations to harm humans, other animals, vegetation, or materials. There are two major types of air pollutants. A primary air pollutant is a chemical added directly to the air that occurs in a harmful concentration. It can be a natural air component, such as carbon dioxide, that rises above its normal concentration, or something not usually found in the air, such as a lead compound. A secondary air pollutant is a harmful chemical formed in the atmosphere through a chemical reaction among air components.We normally associate air pollution with smokestacks and cars, but volcanoes, forest fires, dust storms, marshes, oceans, and plants also add to the air chemicals we consider pollutants. Since these natural inputs are usually widely dispersed throughout the world, they normally don‟t build up to harmful levels. And when they do, as in the case of volcanic eruptions, they are usually taken care of by natural weather and chemical cycles2.As more people live closer together, and as they use machines to produce leisure, they find that their leisure, and even their working hours, become spoilt by a byproduct of their machines – namely, noise,The technical difficulties to control noise often arise from the subjective-objective nature of the problem. You can define the excessive speed of a motor-car in terms of a pointer reading on a speedometer. But can you define excessive noise in the same way? You find that with any existing simple “noise-meter”, vehicles whichare judged to be equally noisy may show considerable differenceon the meter.Though the ideal cure for noise is to stop it at its source, thismay in many cases be impossible. The next remedy is to absorb iton its way to the ear. It is true that the overwhelming majority ofnoise problems are best resolved by effecting a reduction in thesound pressure level at the receiver. Soft taped music in restaurantstends to mask the clatter of crockery and the conversation at thenext table. Fan noise has been used in telephone booths to mask speech interference from adjacent booths. Usually, the problem is how to reduce the sound pressure level, either at source or on the transmission path.6 ANALYTICAL INSTRUMENT MARKETThe market for analytical instruments is showing a strength only dreamed about as little as five years ago. Driven by the need for greater chemical analysis coming from quality control and government regulation, a robust export market, andnew and increasingly sophisticated techniques, sales are increasingrapidly1.The analytical instrument business' worldwides sales arenearly double their value of five years ago, reaching $ 4.1 billion in1987. Such growth is in stark contrast to the doldrums of severalyears ago when economic recession held back sales growth to littleor nothing. In recent years, the instrumentation market hasrecovered, growing at nearly 9% per year, and it‟s expected t o continue at this rate at least until the 1990. With sales increases exceeding inflation, the industry has seen the real growth demonstrating the important role of chemical instrumentation in areas such as research and development, manufacturing, defense, and the environment in a technologically advancingworld2.Chromatography is the fastest-growing area, comprising 40%, or $ 1.5billion, in 1987 world sales. Chromatographic methods are used extensively inindustrial labs, which purchase about 70% of the devices made, for separation,purification, and analysis. One of the biggest words in all forms of chromatography is “biocompatibility.” Biocompatible instruments are designed to have chemically inert, corrosion-resistant surfaces in contact with the biological samples.Gas Chromatography sales are growing at about the same rate as the instrument market. Some of the newest innovations in GC technology are the production of more instruments with high-efficiency, high-resolution capillaries and supercritical fluid capability.Despite having only a 3% share of the GC market, supercritical fluid chromatography (SFC) has attracted a great deal of attention since its introduction around 1985 and production of the first commercial instrument around 1986. SFC, which operates using asupercritical fluid as the mobile phase, bridgesthe gap between GC and HPLC. The useof these mobile phases allows for higherdiffusion rates and lower viscosities thanliquids, and a greater solvating powerthan gases.Another area showing tremendous growth is ion chromatography (IC). From growth levels of 30% per year in the U.S. and similar levels worldwide, the rate is expected to drop slightly but remain high at 25%. The popularity of IC has been enhanced through extending its applicability from inorganic systems to amino acids and other biological systems by the introduction of biocompatible instruments.Mass spectrometry (MS) sales have been growing about 12% annually. Sales have always been high, especially since MS is the principal detector in a number of hyphenated techniques such as GC-MS, MS-MS, LC-MS, and GC-MS accounts for about 60% of MS sales since it is used widely in drug and environmental testing. Innovations in interface technology such as inductively coupled plasma/MS, SFC/MS, and thermospray or particle beam interfaces for LC-MS have both advanced the technology and expanded the interest in applications. Recent MS instruments with automated sampling and computerized data analysis have added to the attractiveness of the technique for first time users.Spectroscopy accounts for half of all instrument sales and is the largestoverall category of instruments, as the Alpert & Suftcliffe study shows. It can be broken down evenly into optical methods and electromagnetic, or nonoptical, spectroscopies. These categories include many individual high-cost items such as MS, nuclear magnetic resonance spectrometers, X-ray equipment, and electron microscopy and spectroscopy setups. Sales of spectroscopic instruments that are growing at or above the market rate include Fourier transform infrared (FTIR), Raman, plasma emission, and energy dispersive X-ray spectrometers. Others have matured and slowed down in growth, but may still hold a large share of the market.The future of analytical instrumentation does not appear to be without its new stars as there continue to be innovations and developments in existing technology. Among these are the introduction of FT Raman, IR dichroism, IR microscopy, and NMR imaging spectrometers. Hyphenated and automated apparatus are also appearing on the market more frequently. New analytical techniques like capillary electrophoresis, gel capillary electrophoresis, scanning tunneling microscopy for the imaging of conducting systems, atomic force microscopy for the imaging of biological systems, and other techniques for surface and materials analysis are already, or may soon be, appearing as commercialized instruments. And, if the chemical industry continues to do well in the next few years, so too will the sales of analytical instrumentation.The effect of alcohol have both medical and medicolegal implications. The estimationof alcohol in the blood or urine is relevant when the physician needs toknow whether it is responsible for the condition of the patient. From themedicolegal standpoint the alcohol level is relevant in cases of suddendeath, accidents while driving, and in cases when drunkenness is thedefense plea. The various factors in determining the time after ingestion showing maximum concentration and the quality of the alcohol are the weight of the subject, the amount and concentration of the alcohol, how the alcohol was ingested, the presence or absence of food, and the physical state of the subject concerned1.7 DETERMINATION OF BLOOD ALCOHOL WITH GAS CHROMATOGRAPHYThe effects of alcohol vary among individuals and for the same individuals at different times. The action depends mostly on the environment and thetemperament of the individual and on the degree of dilution of the alcoholconsumed. The habitual drinker usually shows relatively less effect than wouldbe seen with an occasional drinker from the same amount of alcohol. Drugspotentiate the effect of alcohol.Many cases document the synergistic effect of alcohol and barbiturates as a cause of death in cases appearing to be suicide. Alcohol itself is probably the most frequent cause of death due to poisoning.A gas-solid chromatographic technique using flame ionization detection and a Porapak Q column has been used for the identification and determination of ethanol, isopropanol, and acetone in pharmaceutical preparations. The technique involves direct injection of an aqueous dilution of the product and thus is simple and direct.Sample Preparation. Two 0.5-ml volumes of an isobutanol internal standard (10 mg/ml water; pipette 12.4 ml of isobutanol and dilute to 1 liter with water) are pipetted into two different 2-dram (7.4-ml) shell vials, one market “known.” and the other “unknown.” A 0.5-ml portion of the ethanol working standard (50 mg/100ml of blood; pipette 5ml of ethanol stock solution; dilute 12.7 ml of absolute ethanol to 1 liter with water, and dilute with 100 m l of blood from blood bank) is transferred to the vial marked “known.” The。
2012药学英语翻译
Unit 1 Green pharmacy-herbal medicine1) Plant kingdom once was mere pharmacy of the human race, but now when you get into the modern pharmacy, plant-derived drugs have been hardly found.2) Although today the number of plant-based drugs has been decreased, the effective chemicals in many tables, capsule and bottle-contained drugs are originated from plant kingdom.3) Among chemical substances contained in plants, some must be toxic, but some must be drugs available to us.4) During the millions of years since man came to the earth, he has been doing experiments on a variety of plants about him.5) There exist mistrust, suspicion and hostility between the orthodox medicine and herbal practitioners for many years, which are threatening the possibility of establishing good working relationship.6) When we think of the effectiveness of quinine, the great contributions made by herbal medicine to medical science are quite evident.7) However, in the past few decades, the number of newly-introduced drugs has obviously decreased.8) The medical legacy of our motherland is an inexhaustible new-drug treasure, which remains us to tap with new methods.9) If pharmacological method had not been introduced to the study of vinca rosea, the discovery of vincaleukoblastine would have been postponed by many years.10) Western medicine hardly believes that someone who knows nothing of a disease mechanism could be capable of curing it.Unit 2 How does human body fight disease?People tend to believe that antibiotics were invented by human being, but in fact, they are purely natural products. Since Alexander Fleming, a British biologist discovered anti-microbial substance released by the Penicillium fungi in 1928, it has been learned that this substance can produce powerful antibiotic effect. In fact, antibiotics, are exactly manufactured by organisms, namely, bacteria and fungi, which people aim to destroy. After Fleming’s discovery of penicillin, Selma Walksman in 1943 isolated Streptomycin from a soil bacterium, Streptomycus griseus. Scientists have not made it clear completely why organisms can produce antibiotics. This question has become the topic for discussion.Why antibiotics are useful in medicine is that they can not only kill microbes, but also not kill the body cells as they do to the microbes, body cells are entirely different from those of bacteria cells, so that they can avoid being destroyed at the same time. Thus, antibiotics are called “magic bullet”because they may be particularly used to aim at certain microbes. This feature of antibiotics also makes them essentially different from anti-microbial agents: the latter tends to have poison to a majority of cells, whether the cells of bacteria or the body cells.Unit 3 Drug dependenceStudies indicate that drug dependencies both a health problem and a social concern. The drug dependence affects not only individual’s health but also the public health at the same time. The drug use has obviously and severely negative effects on the human brain and physical health. But drug abuse and addiction have huge and potential threat, because whether the drug is used directlyor indirectly has become the main transmitting ways for many severe communicable diseases, AIDS, hepatitis and pulmonary tuberculosis in particular, plus violent behaviors, etc. The drug addiction is such a complicated and widely health-associated problem that we must duty-boundly put the measures about the public health, extensively-launched education, prevention, treatment and scientific research into our total strategy. Science is offering the foundation to the exploration of public health, which keeps the opposite attitude to the extensively-accepted point of view. It thinks that the drug dependents are made to lose all abilities by drugs, so they cannot rectify their own behaviors. It also offers the suggestions of the foundation for revising the total strategy, so as to reduce the negative effects produced by injection of drugs on the individual and society.Unit 4 The scope of pharmacology1) The science that drugs act on the human body is known as pharmacology, while the scientists who studies this science is called pharmacologist.2) Pharmacology is not a science which can be studied alone, but one that is closely related to other sciences.3) Pharmacologist should not only learn the normal reaction process, but also know how the functions of the human body are affected by diseases.4) If the drug is properly used, it will be a boon to the human race, if not, it will destroy the human race.5) In the first half of the 20th century, the fantastic development has been achieved in the pharmacological field.6) The human race makes constant efforts not only for increasing life expectancy, but also for more healthy life.7) If a patient, the old in particular, constantly uses more than one therapeutic agent, the correlation of the drugs causing toxin tends to occur.8) The clinician is interested primarily in the drugs that are useful in the prevention, diagnosis, and treatment of human disease.9) As most of the natural drugs are now highly purified and differ little from synthetic chemical drugs, the interests of the clinicians in pharmacognosy are correspondingly limited.10) Pharmacodynamics, as a border science, borrows greatly from both the subject matter and the experimental techniques of physiology, biochemistry, microbiology, immunology, genetics, pathology and so on.Unit 5 Combinatorial chemistry and new drugs1) To fight against disease, the immune system generates proteins known as antibodies that bind to invading organisms. But the real case is that the immune system is not to develop a specialized antibody each time it is faced with a new pathogen. In fact, the immune system select the most effective one by mass screening of its antibody repertoire, thus identifying the ones that work best.2) In a process called combinatorial chemistry, chemicals generate a large number of related compounds and then screen the collection for the ones that could have medicinal value.3) In a parallel synthesis, chemists often use a so-called microtiter plate to assemble all the products separately in their own reaction vessels.4) A parallel synthesis and a split-and-mix synthesis are different with that in a parallel synthesis, all the products are assembled separately in their own reaction containers, while in a split-and-mixsynthesis, the related compound are mixed up in the same reaction vessel, which reduces the number of containers required.5) At the end of a split-and-mix synthesis, all the molecules attached to a single bead are found to be of the same structure. Chemists pull out from the mixture the beads that bear biologically active molecules and then, use sensitive detection techniques to determine the molecular makeup of the compound attached.Unit 6 Drug discovery and natural products1) Plant natural products have had, and continue to have, an important role as medicinal and pharmaceutical agents, not only as purified isolates and extractives, but also as lead compounds for synthetic optimization.2) Plant secondary metabolites also show promise for cancer chemoprevention, which has been defined as “the use of non-cytotoxic nutrients or pharmacological agents to enhance intrinsic physiological mechanisms that protect the organism against mutant clones of malignant cells”.3) Nevertheless, the vast majority of the world’s quarter of a million plant species has not been evaluated in pharmaceutical screens, and the small percentage that has been tested has generally been screened for activity against only a few therapeutic targets.4) Although many sampling programs designed to generate large numbers of samples for high-throughput screening programs have been characterized as random, it has been shown that they are neither truly random nor haphazard, but that sampling occurs without preconceived selection of species.5) Three main research approaches are used in drug discovery and development processes：（1）bioactivity- or mechanism of action directed isolation and characterization of active compounds, (2)rational drug design-based modification and analog synthesis, and (3)mechanism of action studies.Unit 7 New drugs and drug delivery systems1) Every drug has its innate pharmacological characteristics. With the right dosage, frequency of administration and route of administration, most patients can get the expected pharmacological eficacy.2) But to different patients, there may be certain ,or even very obvious differences. Patients’physique, quality of drug, microorganisms and environmental factors can all affect drug fuctioning. They can enhance or decrease drug efficacy.3) The main factors that produce individual differences are the differences in drug absorption, distribution, biotransformation and elimination.4) In order to achieve the goal of maximum efficacy and minimum side effect for every patient, it is far from enough just to select drugs according to their pharmaceutical functioning.5) Other factors that influence the efficacy of different drugs must be taken into account, and appropriate therapies should be made according to the particular conditions of different patients. These therapies must be adjusted in time in the course of treatment to conform to patients’changed conditions until they recover.Unit 8 What analytical chemists do ?1) Analytical chemistry aims to resolve two questions:what it is and how much it is, that isqualitative analysis and quantitative analysis. Qualitative analysis is to identify the elements, ions and compounds contained in a sample while quantitative analysis is to determine the exact quantity.2) Analytical chemistry has expanded beyond the bounds of just chemistry, and many have advocated using the name analytical science to describe the field. Even this term falls short of recognition of the role of instrumentation development and application. One suggestion is that we use the term analytical science and technology.3) Analytical chemists work to improve the reliability of existing techniques to meet the demands for better chemical measurements which arise constantly in our society. They adopt proven methodologies to new kinds of materials or to answer new questions about their composition and their reactivity mechanisms.4) Qualitative tests may be performed by selective chemical reactions or with the use of instrumentation. For example, the formation of a white precipitate when adding a solution of silver nitrate to a dissolved sample indicateds the presence of chloride. Infrared spectra will give “fingerprints” of organic compounds or their functional groups.5) The first phase in the testing of banned substances is called fast-screening phase, in which qualitative analysis such as GC or LC is adopted to test suspicious samples. In the second phase, GC-MS is employed for further testing of those suspicious samples. Finally, spectrophotometry or GC is applied for accurate quantification.Unit 9 Nonclinical development of biopharmaceuticals1) The development of a new therapeutic agent involves a multidisciplinary group in many years of work, and with the development of genetic engineering and the production of monoclonal antibodies, it is likely that even more agents should be produced.2) The activity of biopharmaceuticals depends on their complicated conformation based on secondary, tertiary and quaternary structures. These structures cannot be fully defined with our present set of analytical techniques and approaches for potency testing.3) Apart from the intravenous route of drug administration, where a drug is introduced directly into the blood circulation, all other routesof adminstering systemically acting drugs involve the absoption of drug from the place of adminstration into the blood.4) Biopharmaceuticals are pharmaceutical products consisting of (glyco)proteins, and they have a number of characteristics that set them aside from low molecular weight drugs.5) In safety testing and clinical test programs of biopharmaceuticals, questions have to be addressed regarding species specific responses, selection of dosing schedules and route of administration, and the possible occurrence of immunogenicity.Unit 10 The package insert and prescription1) The information the package insert contains is derived from data supplied by investigators and submitted by pharmaceuticalfirm to the FDA, including the chemical structure of the drug, a summary of its pharmacological and toxicological action, its clinical indications and contraindications, precautions, reported adverse reactions, dosage recommendations, and available dosage forms.2) The physician may exercise his professional judgment in the use of any drug. However, if he deviates from the instructions in the package insert and adverse reactions occur, he must beprepared to defend his position in court if there is a malpractice suit.3) If a severe reaction occurred and litigation followed, how would a court react if a physician admitted to the use of this drug for the treatment of some diseases in view of the prohibitions in the package insert? Would the published clinical study, plus the physician’s judgment in prescribing the drug, suffice?4) The FDA cannot requirea pharmaceutical firm to include a new use for the drug product in the insert even if it has been clinically tested and found useful for a given problem. But, if a new use for a drug is not yet included in the package insert, the manufacturer cannot advertise his product for that particular use.5) Today, the FDA’s regulatory scope and authority include ensuring the safety and purity of foods, drugs, medical devices, nutritional supplements, vaccines and cosmetics. Of particular concern to the anesthesiologist is the timely access to drug evaluation, pharmacologic, and medical device data. With the dramatic upsurge in the number of new prescription drugs and over-the-counter supplements, the need for up-to-date drug information has never been more crucial.Unit 11 Development od new drugs(1)1) Formerly, drugs were extracted from natural plant and animal sources. Therapeutic use was empirical and based on traditional experiences.2) The strategies of the drug research include occasional discoveries, random molecular combination, and a planned research of synthesis of a certain specific chemical element.3) Although this is a ideal method of the development of new drugs, it is expensive and there is no guarantee of success.4) When a drug is used by millions of people, it is sure to develop unhealthy response, though this harm is not too big to particular people.5) Most drugs have a maximum safe dose, if the dose exceeds the limited extent, it will produce toxic side effects.6) Penicillin, one of the most powerful bacterium-killers in the world, was incidentally discovered by Fleming.7) The pharmacological experiment of a new drug will determine whether the drug has the desired medicinal functions in model systems.8) The addition of awareness of the biochemical mechanism will make the development of new drugs more rational.9) Extensive formal toxicological tests are required before new drugs can be used on patients.10) Now chemists and biologists attach importance to research fields of molecular biology, biochemical pharmacology, and so on.Unit 12 Development od new drugs(2)1) The rationale for the development of new drugs should be to provide better drugs, better in the sense of being either more effective, safer or cheaper.2) The promotion representative of the pharmaceutical manufacturer has been trained to promote a certain new product.3) The clinical evaluation of new drugs should be made after the study on animals proves effective.4) A new drug evaluation in man can be considered in four phases, each of which should be doneunder the strict supervision.5) Dose-ranging study should only be performed in volunteers who are informed about the implications of the tests, and who give their consent freely.6) As dose-ranging study may have a certain dangerous nature, it can only be carried out under medical supervision.7) A large scale of clinical trials in phase 3 will establish the new drug’s profile of action and frequency of adverse effects.8) The large cost of the drug development is borne by the pharmaceutical industry, which justifiably expects to recoupe it when the product is finally marketed.9) Information about new drugs published in well-established journals is more believable than the introductions by the representatives living on promotion.10) Heavy investment used in promotion of new drugs has not only led to the use of undistinguished new drugs but also raised the cost of the drugs.Unit 13 The impact of pharmaceutical care on drug therapy1) The focus of pharmaceutical care is to optimize drug therapy, minimize drug-related problems, and improve self-management for the purpose of achieving the optimal outcome to improve the patients’ quality of life.2) Diabetes mellitus is a group of metabolic diseases characterized by chronic hyperglycemia resulting from defects in insulin secretion, insulin action, or both. Ultimately, it is likely to lead to complications.3) The Pharmaceutical Care process for the patients in the Intervention Group consists of three sections. One of them is provided at hospital, then seamless care at the time of discharge from hospital and the last in the ambulatory setting.4) Pharmaceutical care has a clear benefit and positive impact on patient’s HRQoL, which is feasible in the hospital and in the community setting.5) The result of the study demonsreates that patients who do not receive intensified PC have a higher chance of deteriorationg their quality of life.Unit 14 FDA’s responsibilities and activities1) Before a new drug goes to the market and is widely used, the manufacturer should get the license from the corresponding authorized government agency(Drug Safety Commiittee in Britain; Food and Drug Administration in USA;Medical Products Agency in Sweden and etc).2) The new drug probably has been taken by more than 3000 healthy volunteers or patients in controlled studies before marketed unless it is only designed for some orphan diseases in small scale trials.3) At the present stage, most of the pharmacological effects are well-known and the side effects caused by overdosages have been documented. However, the recognition of unpredicted toxic and side effects are rarely known by humans until after the extensive use of the drugs.4) Continuous use of beta receptor blocking drug practolol for a comparative period of time may produce a syndrome of ocular mucosa and dermis, which had been discovered after several years.5) In similar manner, when thalidomide was discovered to make pregnant women who had taken the medicine during their early pregnancy bear babies with limb deformity, it had been sold on market for a few years.Unit 15 Good manufacturing practices(GMP)1) GMP is probably the most widespread quality system followed across the pharmaceutical industry as a whole. GMP compliance is a requirement within the R&D environment for the manufacture and testing of clinical trial materials (both drug product and API) and for commercial manufacture and testing of these materials.2) Although the FD&C Act requires all drugs (products and APIs) to be manufactured to cGMP, the regulations 21CFR parts 210 and 211 are only mandatory for the manufacture of drug products and not APIs. It is only with the issue of ICH Q7 A that the worldwide pharmaceutical industry finally received detailed guidance for manufacture of APIs for boh commercial and R&D purposes.3) There have been distinct and fundamental differences between USA regulation and EU/UK requirements for GMP. The US required all drugs to be made to GMP requirements and performed inspections throughout the world in support of these requirements. In the UK, only drug products and biological manufacturers (not APIs, except some specified antibiotics) were inspected by the regulatory authority fot compliance to GMP.4) An API is normally prepared by chemical processes and even if purification is involved at each stage of manufacture, impurities in APIs can not be removed thoroughly. Therefore, trace impurities are allowed to be present in drug product to a limited extent.5) Harmonization with the US through a Mutual Recognition Agreement（MRA）is seen as a big saving of inspection resources to both the EU and the USA, through mutual acceptance of API facility inspection reports.。
Unit 12 what is analytical chemistry
一、New words and expressions
Qualitative 定性的 quantitative 定量的 Surface analysis 表面分析 Volumetric analysis 容量分析 antacid 抗酸剂 Neutralize 中和 ceramic 陶器的 Gravimetric analysis 重量分析 Titration 滴定 Molarity 摩尔浓度
（2）nondestructive analysis methe classify of analytical chemistry 、
（1）Wet chemical methods: 液相法 ）
Volumetric analysis 容量分析 Gravimetric analysis 重量分析 Acid –base titration 酸碱滴定 Oxidation-reduction titration 氧化还原滴定 Gravimetric determinations 重量测定
二、Contents
1、The definition of analytical chemistry 、
Functional definition: the qualitative and quantitative characterization of matter. Characterization:
The identification of how much of a species is present in a sample.
鉴定样品中所含某种化学成分的量。 鉴定样品中所含某种化学成分的量。
药学英语课文翻译 课后翻译节选 中英双语对照 第四版
本篇包括人卫第四版Unit 3B，Unit4A，5A，8A，10A，12AB，13A等七篇课文Unit 3 Text B The Other Side of Antibiotics抗生素的另一面Antibiotics have eliminated or controlled so many infectious diseases that virtually everyone has benefited from their use at one time or another. Even without such personal experience, however, one would have to be isolated indeed to be unaware of the virtues, real and speculative, of these “miracle” drugs1. The American press, radio, and television have done a good job of reporting the truly remarkable story of successes in the chemical war on germs. What′s more, any shortcomings on their part have been more than made up for by the aggressive public relations activity of the pharmaceutical companies which manufacture and sell antibiotics.抗生素可以消除或控制很多种感染疾病，以致几乎每人生病时都习惯于使用它而受益，但是如果一个人没有这样的亲身经历，他必定是离群索居才会不知道这些“特效药物”或真实或推测的优点。
Chemistry--Today and Tomorrow
化学是最古老的科学之一。在改变人类生活方面，它
也是最有成效的科学之一。应用化学于生产产品的工业—— 化学过程工业——在先进社会的生产中占有最大的份额。
内蒙古科技大学化学与ห้องสมุดไป่ตู้工学院
2
To study this course, I do not assume that you have taken any course in chemistry, but I believe that at some point you have learned that “ chemicals ” consist of molecules made up of atoms of the elements. For example, a molecule of water contains two atoms of hydrogen and one atom of oxygen, hence the formula H2O. These atoms are linked together by chemical bonds. 学习这门课程，并不要求事先学过任何化学课程，但我 相信你们以前一定学过“化学物品”是由元素的原子结合成 的 分子组成的。例如，一个水分子含有两个氢原子和一个氧原 子，因此化学式为H2O。这些原子之间以化学键相联结。
◎THE FUTURE 关于未来 Exercise:
内蒙古科技大学化学与化工学院
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1.1 What is chemistry? 什么是化学？
Chemistry is the science that tries to understand the
properties of substances and the changes that substances undergo. It is concerned with substances that occur naturally—the minerals of the earth, the gases of the air, the water and salts of the seas, the chemicals found in living creatures—and also with new substances created by humans. It is concerned with natural changes—the burning of a tree that has been struck by lighting, the chemical changes that are central to life — and also with new transformations invented and created by chemists.
WhatisAnalyticalChemistry？
WhatisAnalyticalChemistry？Analytical chemistry is the branch ofchemistry that deals with the analysis ofdifferent substances.It involves the separation, identification, and the quantification of matter. It involves the use of classical methods along with modern methods involving the use of scientific instruments.Analytical chemistry involves the following methods:•The process of separation isolates the required chemical species which is to be analyzed from a mixture.•The identification of the analyte substance is achieved via the method of qualitative analysis.•The concentration of the analyte in a given mixture can be determined with the method of quantitative analysis.Today, the field of analytical chemistry generally involves the use of modern, sophisticated instruments. However, the principles upon which these instruments are built can be traced to more traditional techniques.Recommended Videos2,61,430Methods Used in Analytical ChemistryThe methods used to determine the identity and the quantity of the analytes in the field of analytical chemistry can be broadly divided into classical and instrumental methods.1. Classical Methods•There exist many classical methods of checking for the presence or absence of a particular compound in a given analyte. One such example is the acid test for gold.•Another example of a classical method for qualitative analysis is the Kastle-Meyer test which employs phenolphthalein as an indicator to check for the presence of haemoglobin in the given analyte.•Flame tests can be used to check for the presence of specific elements in an analyte by exposing it to a flame and observing the change in the colour of the flame.•Gravimetric analysis is a classical method of quantitative analysis, which can be used in analytical chemistry to determine the amount of water in a hydrate by heating it and calculating the weight of the water lost.•One of the better known classical methods of quantitative analysis is volumetric analysis (also known as titration). In the titration method, a reactant is added to the analyte till an equivalence point is obtained.2. Instrumental Methods•Spectroscopy involves the measurement of the interaction between electromagnetic radiation and the atoms or molecules belonging to a sample.•With the help of electric fields and magnetic fields, the method of mass spectroscopy is used to measure the ratio of the mass of the molecule to its charge.•A common instrumental method used in the field of analytical chemistry is electrochemical analysis. In this method, the analyte is placed in an electrochemical cell and the voltage or the current flowing through it is measured.•The interaction between the analyte and energy in the formof heat is studied in the discipline of analytical chemistry known as calorimetry. A calorimeter is an instrument that is used to measure the heat of a chemical reaction.It can be noted that even biological measurements are made with the help of this branch of chemistry, and this field is known as bioanalytical chemistry.Branches of Analytical ChemistryTwo sub-branches come under analytical chemistry namely quantitative analysis and qualitative analysis which can be explained as follows. These two methods form the backbone of many educational labs of analytical chemistry.1. Quantitative AnalysisQuantitative Analysis is a method of determining the absolute or relative quantity regarding the concentration of one or more substances present in a sample or compound.For example, Take a sample of an unknown solid substance. The chemists first use “qualitative” methods to identify what type of compound is present in the sample; then he adopts the quantitative analysis procedure to determine the exact amount or the quantity of the compound present in the sample.Some of the Quantitative analysis techniques include Gravimetric Analysis and Volumetric analysis.2. Qualitative AnalysisQuality means the standard or the feature of one substance. Hence Qualitative analysis method deals with the determination of the quality of a particular compound, irrespective of its quantity or concentration. In simpler words, the qualitative analysis does not measure the amount of the substance but measures the quality of that material. One of the best examples of this type of method is the observation of a chemical reaction,whether there will be a change in colour or not.The qualitative analysis method can be measured in different ways such as Chemical tests, flame tests, etc. Several such tests are widely used in salt analysis (identification of the cation & anion of inorganic salts).3. Importance of Analytical ChemistryAnalytical chemistry is the branch which is taught in almost all schools and colleges. But the applications of it are made in pharmaceutical industries, food factories, chemical industries, agricultural industries and in scientific laboratories. The tools used for this purpose are quite expensive which one cannot afford at home.Applications of Analytical ChemistrySome important applications of this branch of chemistry are listed below.•The shelf lives of many medicines are determined with the help of analytical chemistry.•It is used to check for the presence of adulterants in drugs.•Soil can be tested to check for appropriate concentrations of minerals and nutrients that are necessary for plant growth.•It is employed in the process of chromatography where the blood samples of a person are classified.Applications of Analytical Chemistry in Chromatography•The concentration of the pesticide residues and the contaminants in a given food sample can also be determined via analytical chemistry.•It also has many important applications in medicine, with its use in the testing of cholesterol and glucose levels in a blood sample.•Analytical chemistry is an integral part of forensic science, clinical analysis, and even environmental analysis.Thus, a brief introduction to the field of analytical chemistry is provided in this article. T o learn more about this branch of chemistry along with other branches, such as inorganic chemistry, register with BYJU’S and download the mobile application on your smartphone.。
药学英语第四版课后翻译
Unit One1. A full appreciation of the physiology of a living organism must be based on a soundknowledge of its anatomy. Anatomy does not merely study the separation of parts, but the accurate description of the morphologies and functions of different organs.2.Our daily food intake must match requirements and any excess must be excreted for balanceto be maintained.3.The process of stabilization of the internal environment is called homeostasis and is essentialif the cells of the body are to function normally.4.Human cells have the ability to break down large molecules to smaller ones to liberatesufficient energy for their activities.5.As long as normal conditions are maintained in this internal environment, the cells of the bodycontinue to live and function properly.Unit Two1.Biochemistry asks how the thousands of different biomolecules interact with each other toconfer the remarkable properties of living organisms.2.Enzymes are catalysts that accelerate the rates of biological reactions. Each enzyme is veryspecific in its foundation and acts only in a particular metabolic reaction.3.One of the most fruitful approaches to understand biological phenomena has been to purify anindividual chemical component, such as protein, from a living organism and to characterize its chemical structure or catalytic activity.4.The chemical principles that govern the properties of biological molecules include thecovalent bonding of carbon with itself and with other elements and the functional groups that appear in common biological molecules, etc.5.The basic unit of DNA is a linear polymer of four different monomeric subunits,deoxyribonucleotides, arranged in a precise linear sequence.Unit Four1.The science of the effects on the body is called pharmacology, and the scientists who study itare pharmacologists. Pharmacology is not a science that can be studied on its own, but that closely related to other branches of science. Pharmacologists should not only understand he normal processes that take place in the body, but know how the functions of the body are affected by disease.2.For physicians and medical students, the scope of pharmacology is not so expansive as itscommon definition. The clinician is interested primarily in drugs that are useful in the prevention, diagnosis, and treatment of human disease, or in the prevention of pregnancy.3.All physicians should share the responsibility to resolve kinds of sociological problemscaused by the abuse of drugs. Properly used, drugs are great blessing to mankind; improperly used, they could destroy human race. When a patient, particular the elderly is prescribed frequently to take more than one therapeutic agent, drug interactions resulting in toxicity will occur.4.At one time, it was essential for the physician to have broad botanical knowledge, becausethey had to possess the ability and skill to select proper plants from which to prepare his owncrude medicinal preparation.5.The study of biochemical and physiological effects of drugs and their mechanisms of action istermed as pharmacodynamics, whose uniqueness lies mainly in that its attention is focused on the characteristics of the drug. As a broader science, it borrows freely from both the theories and experimental techniques of physiology, biochemistry, immunology, and pathology.Unit Five1.To fight against disease, the immune system generates proteins known as antibodies that bindto invading organisms. But the real case is that the immune system is not to develop a specialized antibody each time it is faced with a new pathogen. In fact, the immune system select the most effective one by mass screening of its antibody repertoire, thus identifying the ones that work best.2.In a process called combinatorial chemistry, chemists generate a large number of relatedcompounds and then screen the collection for the ones that could have medicinal value.3.In a parallel synthesis, chemists often use a so-called microtiter plate to assemble all theproducts separately in their own reaction vessels.4. A parallel synthesis and a split-and-mix synthesis are different with that in a parallel synthesis,all the products are assembled separately in their own reaction containers, while in a split-and-mix synthesis, the related compounds are mixed up in the same reaction vessel, which reduces the number of container required.5.At the end of a split-and-mix synthesis, all the molecules attached to a single bead are foundto be of the same structure. Chemists pull out from the mixture the beads that bear biologically active molecules and then, use sensitive detection techniques to determine the molecular makeup of the compound attached.Unit Six1.Plant natural products has had, and continued to have, an important role as medicinal andpharmaceutical agents, not only as purified isolates and extractives, but also as lead compounds for synthetic optimization.2.Plant secondary metabolites also show promise for cancer chemoprevention, which has beendefined as “the use of non-cytotoxic nutrients or pharmacological agents to enhance intrinsic physiological mechanisms that protect the organism against mutant clones of malignant cells.”3.Nevertheless, the vast majority of the world’s quarter of a million plant species has not beenevaluated in pharmaceutical screens, and the small percentage that has been tested has generally been screened for activity against only a few therapeutic targets.4.Although many sampling programs designed to generate large numbers of samples forhigh-throughput screening programs have been characterized as random, it has been shown that they are neither truly random nor haphazard, but that sampling occurs without preconceived selection of species.5.Three main research approaches are used in drug discovery and development processes: (1)bio-activity or mechanism of action-directed isolation and characterization of active compounds, (2) rational drug design-based modification and analog synthesis, and (3) mechanism of action studies.Unit Seven1.Absorption is the process of a drug entering（现在分词作后置定语）systemic circulationfrom its site of administration. Except direct injection into the blood vessels, other routs of administration involve the transport of cell membrane.2.Drug absorption, especially those orally administered drugs, depends on many factors, such asthe intrinsic characteristics of the drug, dosage form, food, patient age and the like.3.The distribution of a drug in the body is even and is in a state of dynamic equilibrium, that is,it changes constantly with the absorption and elimination of the drug.4.After a drug enters the blood, it will more or less bind to plasma protein, but this binding isloose and reversible, and is always in a state of equilibrium.5.Bioavailability is the relative quantity and rate of drugs with different dosage forms which areabsorbed and reach the systemic circulation; it is concerned with the intensity and speed of drug action.Unit Eight1.Analytical chemistry aims to resolve two questions: what it is and how much it is, that isqualitative analysis and quantitative analysis. Qualitative analysis is to identify the elements, ions and compounds contained in a sample while quantitative analysis is to determine the exact quantity.2.Analytical chemistry has expanded beyond the bounds of just chemistry, and many haveadvocated using the name analytical science to describe the field. Even this term falls short of recognition of the role of instrumentation development and application. One suggestion is that we use the term analytical science and technology.3.Analytical chemists work to improve the reliability of existing techniques to meet thedemands for better chemical measurements which arise constantly in our society. They adopt proven methodologies to new kinds materials or to answer new questions about their composition and their reactivity mechanisms.4.Qualitative test may be performed by selective chemical reaction or with the use ofinstrumentation. For example, the formation of a white precipitate when adding a solution of silver nitrate to a dissolved sample indicates the presence of chloride. Infrared spectra will give “fingerprints” of organic compounds or their functional groups.5.The first phase in the testing of banned substance is called fast-screening phase, in whichqualitative analysis such as GC or LC is adopted to test suspicious samples. In the second phase, GC-MS is employed for further testing of those suspicious samples. Finally, spectrophotometry or GC is adopted for accurate quantification.Unit Nine1. The development of a new therapeutic agent involves a multidisciplinary group in many years of work, and with the development of genetic engineering and the production of monoclonal antibodies, it is likely that even more agents should be produced.2. The activity of biopharmaceuticals depends on their complicated conformation based on secondary, tertiary and quaternary structures. These structures cannot be fully defined with our present set of analytical techniques and approaches for potency testing.3. Apart from the intravenous route of drug administration, where a drug is introduced directly into the blood circulation, all other routes of administering systemically acting drugs involve theabsorption of drug from the place of administration into the blood.4. Biopharmaceuticals are pharmaceutical products consisting of (glyco) proteins, and they have a number of characteristics that set them aside from low molecular weight drugs.5. In safety testing and clinical test programs of biopharmaceuticals, questions have to be addressed regarding species specific responses, selection of dosing schedules and route of administration, and the possible occurrence of immunogenicity.Unit Eleven1) The information the package insert contains is derived from data supplied by investigators and submitted by pharmaceutical firm to the FDA, including the chemical structure of the drug, a summary of its pharmacological and toxicological action, its clinical indications and contraindications, precautions, reported adverse reactions, dosage recommendations, and available dosage forms.2) The physician may exercise his professional judgment in the use of any drug. However, if he deviates from the instructions in the package insert and adverse reactions occur, he must be prepared to defend his position in court if there is a malpractice suit.3) If a severe reaction occurred and litigation followed, how would a court react if a physician admitted to the use of this drug for the treatment of some diseases in view of the prohibitions in the package insert? Would the published clinical study, plus the physician’s judgment in prescribing the drug, suffice?4) The FDA cannot require pharmaceutical firm to include a new use for the drug product in the insert even if it has been clinically tested and found useful for a given problem. But, if a new use for a drug is not yet included in the package insert, the manufacturer cannot advertise his product for that particular use.5) Today, the FDA’s regulatory scope and authority include ensuring the safety and purity of food s, drugs, medical devices, nutritional supplements, vaccines and cosmetics. Of particular concern to the anesthesiologist is the timely access to drug evaluation, pharmacologic, and medical device data. With the dramatic upsurge in the number of new prescription drugs and over-the-counter supplements, the need for up-to-date drug information has never been more crucial.Unit Twelve1) Formerly, drugs were extracted from natural plant and animal sources. Therapeutic use was based on traditional experiences.2) Drug development strategies involve serendipity, molecular roulette, programmed basic research with synthesis of specific chemical, etc.3) When a drug is used by millions, there are certain to be adverse reactions even though the risk to any individual is small.4) The pharmacological experiment on a new drug determines whether the drug has the desired profile in model system.5) Chemists and biologists have now attached importance to such fields of research as molecular biology and biochemical pharmacology.。
What is chemistry
chemistry
• Chemistry is such abroad,all-encompassing area of
study that people almost despair in trying to define
it.Indeed,some have taken a cop-out approach by defining chemistry as "what chemists do".But that won't do;it's much too narrow a view.
化学对社会和个人都有影响。化学是生物学，保健科学， 农业科学和地球科学的语言和基本工具。从微小的原子核 到无限的宇宙，化学给整个自然界以启迪。
• I believe that knowledge of chemistry can help you.Chemistry can be related immediately to problems and opportunities in the life and health science.And we believe that this can make the study
化学是如此广泛的、涵盖一切的学科领域，以至于人们在 尝试给它下定义时几乎绝望了。事实上，有些人采取一种 逃避的方法，把化学定义为“化学家们所做的”。但那是 行不通的，它的视野范围太狭窄了。
• Chemistry is we all do.We bathe ,clean and cook.We put chemicals on our faces ,hands and hair.Collectively,we use tens of thousands of consumer chemical products in our homes.
药学英语 标准试卷6
一、翻译（共20分,每题1分）。
1 戊烷2 腺苷酸3 氯4 碘5 脯氨酸6 色氨酸7 酮8 酰胺9 CaCO310 氯化钠11 Cyclohexane 12 Decane13 Butanol 14 Sodium15 Tyrosine 16 Ethyl acetate17 Mercury 18 Phenol19 Potassium carbonate 20 Cysteine答案： 1 Pentane 2 Adenylic acid 3 Chlorine 4 Iodine5 Proline6 Tryptophan7 Acetone 8 Amide9 Ccalcium carbonate 10 Sodium chloride11 环己烷12 癸烷13 丁醇14 钠15 酪氨酸16 乙酸乙酯17 汞18 酚19 碳酸钾20 半胱氨酸二、写出下列缩写的英文全称并翻译（共10分,每题2分）。
1 DMSO:2 TCM:3 GMP:4 HPLC:5 UV/visible: 答案： 1 dimethyl sulfoxide 二甲基亚砜2 Traditional Chinese Medicine 中医3 Good Manufacturing Practice 药品生产和质量管理规范试卷（A）共（5）页第（1 ）页4 High Performance (Pressure) Liquid Chromatography 高效液相色谱5 Ultraviolet-visible spectroscopy 紫外分光光度法三、判断，并用×√表示（共16分,每题2分）。
1 （）Analytical chemists also make important contributions to fields as diverse as forensics, archaeology, and space science.2（）A selective reaction or test is one that occur only with the substance of interest.3 （）Lead compounds can be obtained from a variety of different sources such as the flora and fauna of the natural world, or synthetic compounds made in the laboratory. There is also the potential of designing lead compounds using computer modeling or NMR spectroscopic studies.4 （）Biomolecules are compounds of nitrogen.5 （）By conyention, pharmacokinetics is defined as the study of the time-course of drug absorption, distribution, metabolism and excretion, whereas the term pharmacodynamics refers to the corresponding pharmacological response.6 （）The degree of aqueous solubility of the drug affects directly the bioavailability of the drug.7 （）Direct comparison with authentic (if available) should be carried out as final confirmation.8 （）Drag design aims to remove the desirable effects of the lead compound and to improve the undesirable effects.答案: 1 √ 2 × 3 √ 4 × 5 √ 6 ？7 √8 ×四、单选题（共14分,每题2分）。
lesson3analyticalchemistry翻译
Lesson 3 Analytical ChemistryAnalytical chemistry is the science of making quantitative measurements. In practice, quantifying analytes in a complex sample becomes an exercise in problem solving. To be effective and efficient, analyzing samples requires expertise in:1the chemistry that can occur in a sample2analysis and sample handling methods for a wide variety of problems (the tools-of-the-trade)3proper data analysis and record keepingTo meet these needs, Analytical Chemistry courses usually emphasize equilibrium, spectroscopic and electrochemical analysis, separations, and statistics.Analytical chemistry requires a broad background knowledge of chemical and physical concepts. With a fundamental understanding of analytical methods, a scientist fac ed with a difficult analytical problem can apply the most appropriate technique(s). A fundamental understanding also makes it easier to identify when a particular problem cannot be solved by traditional methods, and gives an analyst the knowledge that is needed to develop creative approaches or new analytical methods.1 GravimetryGravimetry is the quantitative measurement of an analyte by weighing a pure, solid form ofthe analyte. Obtaining pure solids from solutions containing an unknown amount of a metal ion is done by precipitation.Since gravimetric analysis is an absolute measurement, it is a principal method for analyzing and preparing primary standards. A typical experimental procedure to determine an unknown concentration of an analyte in solution is as follows:quantitatively precipitate the analyte from solutioncollect the precipitate by filtering and wash it to remove impuritiesdry the solid in an oven to remove solventweigh the solid on an analytical balancecalculate the analyte concentration in the original solution based on the weight of theprecipitateGravimetric Determination of Iron:Determine constant weight of the cruciblesOxidation of iron samplePrecipitation of iron hydroxideIgnition of iron hydroxide to iron oxideDetermine constant weight of the crucibles plus iron oxideCalculation of iron in the sample2 TitrationTitration is the quantitative measurement of an analyte in solution by completely reacting itwith a reagent solution. The reagent is called the titrant and must either be prepared from a primary standard or be standardized versus a primary standard to know its exact concentration.The point at which all of the analyte is consumed is the equivalence point. The number of moles of analyte is calculated from the volume of reagent that is required to react with all of the analyte, the titrant concentration, and the reaction stoichiometry.The equivalence point is often determined by visual indicators are available for titrations based on acid-base neutralization, complexation, and redox reactions, and is determined by some type of indicator that is also present in the solution. For acid-base titrations, indicators are available that change color when the pH changes. When all of the analyte is neutralized, further addition of the titrant causes the pH of the solution to change causing the color of the indicator to change.If the pH of an acid solution is plotted against the amount of base added during a titration, the shape of the graph is called a titration curve. All acid titration curves follow the same basic shapes.Strong Acid Titration CurveAt the beginning, the solution has a low pH and climbs as the strong baseis added. As the solution nears the point where all of the H+ are neutralized,the pH rises sharply and then levels out again as the solution becomes morebasic as more OH- ions are added.Manual titration is done with a buret, which is a long graduated tube toaccurately deliver amounts of titrant. The amount of titrant used in the titrationis found by reading the volume of titrant in the buret before beginning thetitration and after reaching the endpoint. The difference in these readings is thevolume of titrant to reach the endpoint. The most important factor for making accurate titrations isto read the buret volumes reproducibly. The figure shows how to do so by using the bottom of the meniscus to read the reagent volume in the buret.The end point can be determined by an indicator as described above or by an instrumental method. The most common instrumental detection method is potentiometric detection. The equivalence point of an acid-base titration can be detected with a pH electrode. Titrations, such as complexation or precipitation, involving other ions can use an ion-selective electrode (ISE). UV-vis absorption spectroscopy is also common, especially for complexometric titrations where a subtle color change occurs.For repetitive titrations, autotitrators with microprocessors are available that deliver the titrant, stop at the endpoint, and calculate the concentration of the analyte. The endpoint is usually detected by some type of electrochemical measurement. Some examples of titrations for which autotitrators are available include:Acid or base determination by pH measurement with potentiometric detection.Determination of water by Karl Fischer reagent (I2and SO2in methyl alcohol and pyridine) with coulometric detection.Determination of Cl in aqueous solution with phenylarsene oxide using amperometric detection.3 ExtractionExtractions use two immiscible phases to separate a solute from one phase into the other. The distribution of a solute between two phases is an equilibrium condition described by partition theory. Boiling tea leaves in water extracts the tannins, theobromine, and caffeine (the good stuff) out of the leaves and into the water. More typical lab extractions are of organic compounds out ofan aqueous phase and into an organic phase.Analytical Extractions4 Precipitation (Insoluble Salts)Many metal ions form compounds that are insoluble in water. We call them insoluble salts or precipitates. Common precipitates are carbonates, hydroxides, sulfates, and sulfides. Ions that we consider spectator ions when discussing acid-base equilibria will form insoluble salts.An insoluble salt in contact with water maintains an equilibrium with the ions. In simple cases where there are no common ions or competing equilibria, the ion concentrations depend only on the equilibrium constant for the particular precipitate. When we talk about solubility equilibria we always write the equilibrium with the solid on the left. For example:Ba(IO3)2 (s)Ba2+(aq) + 2 IO3-(aq)The equilibrium constant expression for an insoluble salt is written following the same rulesas for any other equilibrium. The equilibrium constant is called the solubility product, K sp. The K sp expression for the above equilibrium is:K sp = [Ba2+][IO3-]2K sp Values for Some PrecipitatesFormula Name K spAgCl silver chloride 1.8×10-10Al(OH)3aluminum hydroxide 2×10-32BaCO3barium carbonate 5×10-9Words & Phrasesamperometric [] adj. 测量电流的analyte [] n. （被）分析物buret [] n. 滴定管；量筒carbonate [] n. 碳酸盐complexometric [] n. 络合滴定（法）coulometric [] n. 库仑滴定crucible [] n. 坩埚endpoint [] n. 端点equilibrium [] n. 平衡（复数形式：equilibria）filtering [] n. 过滤gravimetry [] n. 重量测定法hydroxide [] n. 氢氧化物impurity [] n. 不纯，杂质insoluble [] adj. 不能溶解的，不能解决的neutralization [] n. 中和（作用）reagent [] n. 反应物, 试剂solute [] n. 溶解物，溶质solvent [] n. 溶剂spectroscopic [] adj. 分光镜的，借助分光镜的sulfate [] n. 硫酸盐sulfide [] n. 硫化物tannin [] n. 单宁酸theobromin [] n. 可可碱titrant [] n. 滴定剂（滴定标准液）analytical balance n. 分析天平aqueous phase n. 水相equivalence point n. 等量点graduated tube n. 刻度管immiscible phase n. 不混溶相ion-selective electrode n. 选择性离子电极organic phase n. 有机相partition theory n. 分配理论potentiometric adj. 电势测定的precipitation n. 沉淀(作用) quantitative measurement n. 定量测量solubility solution product n. 溶度积stoichiometry n. 化学计量法，化学计量学第3课分析化学分析化学是定量测量的科学。
第十二单元What is Analytical Chemistry
Unit 12What is Analytical ChemistryPerhaps the most function definition of analytical chemistry is that it is "the qualitative and quantitative characterization of matter ".也许对分析化学最实用的定义是：对物质进行定性和定量的表征。
The word "characterization "is used in a very broad sense .描述这个词被广泛的使用。
It may mean the identification of the chemical compounds or elements present in a sample to answer questions such as "Is there any vitamin E in this shampoo as indicated on the label ?"or "Is this white tablet an aspirin tablet ?"or"Is this piece of metal iron or nickel ?"它可能意味着在回答诸如“在洗发香波中是否如标签所示有维生素E”“这是一个白色阿司匹林片？”或“这块金属是铁或镍”等问题时，对样本中的化合物或元素进行鉴定。
This type of characterization ,to tell us what is present is called qualitative analysis .这种类型的表征，要告诉我们什么是目前被称为的定性分析。
Qualitative analysis is the identification of one or more chemical species present in a material .定性分析是鉴定一个或多个化学物质存在于一个材料中。
分析化学Analytical Chemistry
作用
分析化学是研究物质及其变化的重要 方法之一。在化学学科本身的发展上， 以及与化学有关的各科学领域中，分 析化学都起着一定的作用，如材料科 学、环境科学、能源科学、生命科学、 矿物学、地质学、生理学、医学、农 业及其他科学技术，凡涉及化学现象， 在其研究过程中必用到分析化学，故 有科学技术的“眼睛”之美誉。
技原技仪 领
分析化学发展趋势
整理课件
仪器分析（Instrumental analysis）
以物质的物理和物理化学性质（光、电、 热、磁、声）为基础，借助于特殊的仪 器进行分析的方法，这种方法称为～。
由此形成各分支学科（光学分析法、电
化学分析法、热分析法、色谱法、质谱
法)等。
整理课件Βιβλιοθήκη 如：利用有色溶液对光的吸收可进行光 分 析 ， 例 如 ， 红 色 溶 液 可 吸 收 490 ～ 500nm波长的光，可测自来水中微量的 铁。 Fe3+ + nSCN- = [Fe(SCN)1~6]3-n (n=1~6)
整理课件
2.3 方法原理
化学分析（Chemical analysis） ：以物 质的化学反应为基础，历史悠久，也 称为经典分析法，主要是滴定分析 （容量分析）法和重量分析法。
如：用酸碱滴定法测定醋中的醋酸的含 量，依据反应为： NaOH + HAc = NaAc + H2O
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2.3 方法原理
整理课件
2.4 试样用量
方法
试样质量
常量分析 >0.1g
半微量分析 0.01~0.1g
微量分析 0.1~10mg
超微量分析 <0.1mg
试液体积 >10mL 1~10mL 0.01~1mL <0.01mL
Teaching Students to Think as Analytical Chemists教学生为分析化学家认为精品文档
Other Factors at Play in Designing Courses in Analytical Chemistry
S. Siggia J. Chem. Educ., 1967, 44, 545-546
Other Factors at Play in Designing Courses in Analytical Chemistry
Departmental Resources
Instrumentation Computational technology Budget
R. W. Murray Anal. Chem. 2019, 70, 425A
One Thing Upon Which We All Agree – There Isn’t Enough Time
“How can the professor reap the benefits of teaching fundamentals while bringing in elements of [problem-based learning] without compromising the former? Available time is a very serious constraint. The entire formal lecture time in [undergraduate] analytical chemistry…is about two and one-half solid 40 hour weeks; laboratory time is [equivalent to] three to four weeks. Wow! That’s not much!”
药学英语Unit 8 Text A 注释及译文
Text A What Analytical Chemists DoAnalytical chemistry is concerned with the chemical characterization of matter and the answers to two important questions: what is it (qualitative) and how much is it (quantitative). Chemicals make up everything we use or consume, and knowledge of the chemical composition of many substances important in our daily lives. Analytical chemistry plays an important role in nearly all aspects of chemistry, for example, agricultural, clinical, environmental, forensic, manufacturing, metallurgical, and pharmaceutical chemistry. The nitrogen content of a fertilizer determines its value. Foods must be analyzed for contaminants (e.g., pesticide residues) and for essential nutrients (e.g. vitamin content). The air in cities must be analyzed for carbon monoxide. Blood glucose must be monitored in diabetics (and, in fact, most diseases are diagnosed by chemical analysis). The presence of trace elements from gun powder on a murder defendant’s hand will prove a gun was fired. The quality of manufactured products often depends on proper chemical proportions, and measurement of the constituents is a necessary part of quality control. The carbon of steel will determine its quality. The purity of drugs will determine their efficacy.1、qualitative ['kwɔlitətiv, -tei-] adj.定性的；质的，性质上的2、quantitative ['kwɔntitətiv, -tei-] adj. 定量的；量的，数量的3、consume [kən'sju:m]vt.消耗，消费；使…著迷；挥霍vi. 耗尽，毁灭；耗尽生命4、analytical [,ænə'litik,-kəl] adj.分析的；解析的；善于分析的5、forensic[fɔ'rensik] adj.辩论的；法院的；适于法庭的6、metallurgical [,melə'lə:dʒik,-kəl] adj.冶金学的；冶金的7、nitrogen ['naitrədʒən] n. [化]氮8、contaminant [kən'tæminənt] n.污染物；致污物9、pesticide residues ['pestisaid] ['rezɪ,du:, -,dju:]杀虫剂残留10、carbon monoxide [无化] 一氧化碳11、glucose ['ɡlu:kəus]n.葡萄糖；葡糖（等于dextrose）12、diabetic [,daiə'betik] adj.糖尿病的，患糖尿病的n.糖尿病患者13、defendant [di'fendənt] adj.为自己辩护的；辩护的n.被告14、constituent [kən'stitjuənt]n.成分；选民；委托adj.构成的；选举的分析化学研究物质的化学成分，并且要解决两个问题：样品里有什么化学物质（定性），化学物质的量有多少（定量）。
翻译8
Analytical chemistry is concerned with the chemical characterization of matter and the answers to two important questions: what is it (qualitative) and how much is it (quantitative). Chemicals make up everything we use or consume, and knowledge of the chemical composition of many substances is important in our daily lives. 分析化学是研究物质的化学特征并能回答两个中药问题：是什么（定性）以及有多少（定量）。
我们所使用和消耗的一切都是由化学物质组成的，所以日常生活中了解物质的化学成分是非常重要的。
Analytical chemistry plays an important role in nearly all aspects of chemistry, for example, agricultural, clinical, environmental, forensic, manufacturing, metallurgical, and pharmaceutical chemistry. The nitrogen content of a fertilizer determines its value. Foods must be analyzed for contaminants (e.g., pesticide residues) and for essential nutrients (e.g. vitamin content).分析化学几乎在化学的各个领域都起着至关重要的作用，比如农业，临床，环境，法医，制造业，冶金以及药物化学。
化学学科专业英语
化学学科专业英语Chemistry is a branch of science that deals with the study of the composition, structure, properties, and reactions of matter. It is a fundamental science that plays a crucial role in various industries such as pharmaceuticals, materials science, environmental science, and many others.One of the key concepts in chemistry is the periodic table, which organizes all known elements based on their atomic number, electron configuration, and recurring chemical properties. It provides a systematic way to understand the properties and behavior of elements, as well as predict their reactivity in chemical reactions.Chemical reactions are at the core of chemistry, where substances undergo changes in composition to form new substances. These reactions can be classified intodifferent types such as synthesis, decomposition, single replacement, double replacement, and combustion reactions. Understanding the mechanisms and factors that influence chemical reactions is essential in designing new materials, drugs, and technologies.Analytical chemistry is another important subdisciplineof chemistry that focuses on the qualitative andquantitative analysis of substances. Techniques such as spectroscopy, chromatography, and electrochemistry are commonly used to identify and quantify the components of a sample. Analytical chemists play a crucial role in fields such as environmental monitoring, forensic analysis, and pharmaceutical quality control.Organic chemistry is the study of carbon-containing compounds, which are essential for life and form the basisof many pharmaceuticals, polymers, and agrochemicals. Organic chemists investigate the structure, properties, and reactions of organic compounds to develop new drugs, materials, and sustainable technologies.Inorganic chemistry, on the other hand, deals with compounds that do not contain carbon, such as metals, minerals, and salts. Inorganic chemists study the synthesis, structure, and properties of inorganic compounds to understand their behavior in various applications,including catalysis, electronics, and materials science.Physical chemistry involves the study of the physical properties and behavior of matter, as well as the underlying principles that govern chemical reactions. Thermodynamics, quantum mechanics, and kinetics are key areas of physical chemistry that help scientists understand the energy changes, molecular interactions, and reaction rates in chemical systems.Biochemistry is a multidisciplinary field that combines principles of chemistry and biology to study the chemical processes and molecules that occur in living organisms. Biochemists investigate the structure and function of biomolecules such as proteins, nucleic acids, and carbohydrates to unravel the molecular mechanisms of life and develop new therapies for diseases.Overall, chemistry is a diverse and interdisciplinary field that continues to advance our understanding of the natural world and drive innovation in various industries. By studying the composition, properties, and reactions of matter, chemists contribute to solving global challenges and improving our quality of life.化学是一门研究物质的组成、结构、性质和反应的科学分支。
化学专业英语电子版
Chapter 1 Matter and MeasurementChemistry is the science of matter and the changes it undergoes. Chemists study the composition, structure, and properties of matter. They observe the changes that matter undergoes and measure the energy that is produced or consumed during these changes. Chemistry provides an understanding of many natural events and has led to the synthesis of new forms of matter that have greatly affected the way we live.Disciplines within chemistry are traditionally grouped by the type of matter being studied or the kind of study. These include inorganic chemistry, organic chemistry, physical chemistry, analytical chemistry, polymer chemistry, biochemistry, and many more specialized disciplines, e.g. radiochemistry, theoretical chemistry.Chemistry is often called "the central science" because it connects the other natural sciences such as astronomy, physics, material science, biology and geology.1.1. Classification of MatterMatter is usually defined as anything that has mass and occupies space. Mass is the amount of matter in an object. The mass of an object does not change. The volume of an object is how much space the object takes up.All the different forms of matter in our world fall into two principal categories: (1) pure substances and (2) mixtures. A pure substance can also be defined as a form of matter that has both definite composition and distinct properties. Pure substances are subdivided into two groups: elements and compounds. An element is the simplest kind of material with unique physical and chemical properties; it can not be broken down into anything simpler by either physical or chemical means. A compound is a pure substance that consists of two or more elements linked together in characteristic and definite proportions; it can be decomposed by a chemical change into simpler substances with a fixedmass ratio. Mixtures contain two or more chemical substances in variable proportions in which the pure substances retain their chemical identities. In principle, they can be separated into the component substances by physical means, involving physical changes. A sample is homogeneous if it always has the same composition, no matter what part of the sample is examined. Pure elements and pure chemical compounds are homogeneous. Mixtures can be homogeneous, too; in a homogeneous mixture the constituents are distributed uniformly and the composition and appearance of the mixture are uniform throughout. A solutions is a special type of homogeneous mixture. A heterogeneous mixture has physically distinct parts with different properties. The classification of matter is summarized in the diagram below:Matter can also be categorized into four distinct phases: solid, liquid, gas, and plasma. The solid phase of matter has the atoms packed closely together. An object that is solid has a definite shape and volume that cannot be changed easily. The liquid phase of matter has the atoms packed closely together, but they flow freely around each other. Matter that is liquid has a definite volume but changes shape quite easily. Solids and liquids are termed condensed phases because of their well-defined volumes. The gas phase of matter has the atoms loosely arranged so they can travel in and out easily. A gas has neither specific shape nor constant volume. The plasma phase of matter has the atoms existing in an excited state.1.2. Properties of MatterAll substances have properties, the characteristics that give each substance its unique identity. We learn about matter by observing its properties. To identify a substance, chemists observe two distinct types of properties, physical and chemical, which are closely related to two types of change that matter undergoes.Physical properties are those that a substance shows by itself, without changing into or interacting with another substance. Some physical properties are color, smell, temperature, boiling point, electrical conductivity, and density. A physical change is a change that does not alter the chemical identity of the matter. A physical change results in different physical properties. For example, when ice melts, several physical properties have changed, such as hardness, density, and ability to flow. But the sample has not changed its composition: it is still water.Chemical properties are those that do change the chemical nature of matter. A chemical change, also called a chemical reaction, is a change that does alter the chemical identity of the substance. It occurs when a substance (or substances) is converted into a different substance (or substances). For example, when hydrogen burns in air, it undergoes a chemical change because it combines with oxygen to form water.Separation of MixturesThe separation of mixtures into its constituents in a pure state is an important process in chemistry. The constituents of any mixture can be separated on the basis of their differences in their physical and chemical properties, e.g., particle size, solubility, effect of heat, acidity or basicity etc.Some of the methods for separation of mixtures are:(1)Sedimentation or decantation. To separatethe mixture of coarse particles of a solidfrom a liquid e.g., muddy river water.(2)Filtration. To separate the insoluble solidcomponent of a mixture from the liquidcompletely i.e. separating the precipitate(solid phase) from any solution.(3)Evaporation. To separate a non-volatilesoluble salt from a liquid or recover thesoluble solid solute from the solution.(4)Crystallization. To separate a solidcompound in pure and geometrical form.(5)Sublimation. To separate volatile solids,from a non-volatile solid.(6)Distillation. To separate the constituents of aliquid mixture, which differ in their boilingpoints.(7)Solvent extraction method. Organiccompounds, which are easily soluble inorganic solvents but insoluble or immisciblewith water forming two separate layers canbe easily separated.1.3 Atoms, Molecules and CompoundsThe fundamental unit of a chemical substance is called an atom. The word is derived from the Greek atomos, meaning “undivisible”or “uncuttable”.An atom is the smallest possible particle of a substance.Molecule is the smallest particle of a substance that retains the chemical and physical properties of the substance and is composed of two or more atoms;a group of like or different atoms held together by chemical forces. A molecule may consist of atoms of a single chemical element, as with oxygen (O2), or of different elements, as with water (H2O).A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. The term is also used to refer to a pure chemical substance composed of atoms with the same number of protons. Until March 2010, 118 elements have been observed. 94 elements occur naturally on earth, either as the pure element or more commonly as a component in compounds. 80 elements have stable isotopes, namely all elements with atomic numbers 1 to 82, except elements 43 and 61 (technetium and promethium). Elements with atomic numbers 83 or higher (bismuth and above) are inherently unstable, and undergo radioactive decay. The elements from atomic number 83 to 94 have no stable nuclei, but are nevertheless found in nature, either surviving as remnants of the primordial stellar nucleosynthesisthat produced the elements in the solar system, or else produced as short-lived daughter-isotopes through the natural decay of uranium and thorium. The remaining 24 elements so are artificial, or synthetic, elements, which are products of man-induced processes. These synthetic elements are all characteristically unstable. Although they have not been found in nature, it is conceivable that in the early history of the earth, these and possibly other unknown elements may have been present. Their unstable nature could have resulted in their disappearance from the natural components of the earth, however.The naturally occurring elements were not all discovered at the same time. Some, such as gold, silver, iron, lead, and copper, have been known since the days of earliest civilizations. Others, such as helium, radium, aluminium, and bromine, were discovered in the nineteenth century. The most abundant elements found in the earth’s crust, in order of decreasing percentage, are oxygen, silicon, aluminium, and iron. Others present in amounts of 1% or more are calcium, sodium, potassium, and magnesium. Together, these represent about 98.5% of the earth’s crust.The nomenclature and their origins of all known elements will be described in Chapter 2.A chemical compound is a pure chemical substance consisting of two or more different chemical elements that can be separated into simpler substances by chemical reactions. Chemical compounds have a unique and defined chemical structure; they consist of a fixed ratio of atoms that are held together in a defined spatial arrangement by chemical bonds. Compounds that exist as molecules are called molecular compounds. An ionic compound is a chemical compound in which ions are held together in a lattice structure by ionic bonds. Usually, the positively charged portion consists of metal cations and the negatively charged portion is an anion or polyatomic ion.The relative amounts of the elements in a particular compound do not change: Every molecule of a particular chemical substance contains acharacteristic number of atoms of its constituent elements. For example, every water molecule contains two hydrogen atoms and one oxygen atom. To describe this atomic composition, chemists write the chemical formula for water as H2O.The chemical formula for water shows how formulas are constructed. The formula lists the symbols of all elements found in the compound, in this case H (hydrogen) and O (oxygen). A subscript number after an element's symbol denotes how many atoms of that element are present in the molecule. The subscript 2 in the formula for water indicates that each molecule contains two hydrogen atoms. No subscript is used when only one atom is present, as is the case for the oxygen atom in a water molecule. Atoms are indivisible, so molecules always contain whole numbers of atoms. Consequently, the subscripts in chemical formulas of molecular substances are always integers. We explore chemical formulas in greater detail in Chapter 2.The simple formula that gives the simplest whole number ratio between the atoms of the various elements present in the compound is called its empirical formula. The simplest formula that gives the actual number of atoms of the various elements present in a molecule of any compound is called its molecular formula. Elemental analysis is an experiment that determines the amount (typically a weight percent) of an element in a compound. The elemental analysis permits determination of the empirical formula, and the molecular weight and elemental analysis permit determination of the molecular formula.1.4. Numbers in Physical Quantities1.4.1. Measurement1.Physical QuantitiesPhysical properties such as height, volume, and temperature that can be measured are called physical quantity. A number and a unit of defined size are required to describe physical quantity, for example, 10 meters, 9 kilograms.2.Exact NumbersExact Numbers are numbers known withcertainty. They have unlimited number of significant figures. They arise by directly counting numbers, for example, the number of sides on a square, or by definition:1 m = 100 cm, 1 kg = 1000 g1 L = 1000 mL, 1 minute = 60seconds3.Uncertainty in MeasurementNumbers that result from measurements are never exact. Every experimental measurement, no matter how precise, has a degree of uncertainty to it because there is a limit to the number of digits that can be determined. There is always some degree of uncertainty due to experimental errors: limitations of the measuring instrument, variations in how each individual makes measurements, or other conditions of the experiment.Precision and AccuracyIn the fields of engineering, industry and statistics, the accuracy of a measurement system is the degree of closeness of measurements results to its actual (true) value. The precision of a measurement system, also called reproducibility or repeatability, is the degree to which repeated measurements under unchanged conditions show the same results. Although the two words can be synonymous in colloquial use, they are deliberately contrasted in the context of the scientific method.A measurement system can be accurate but not precise, precise but not accurate, neither, or both. A measurement system is called valid if it is both accurate and precise. Related terms are bias (non-random or directed effects caused by a factor or factors unrelated by the independent variable) and error(random variability), respectively. Random errors result from uncontrolled variables in an experiment and affect precision; systematic errors can be assigned to definite causes and affect accuracy. For example, if an experiment contains a systematic error, then increasing the sample size generally increases precision but does not improve accuracy. Eliminating the systematic error improves accuracy but does not change precision.1.4.2 Significant FiguresThe number of digits reported in a measurement reflects the accuracy of the measurement and the precision of the measuring device. Significant figures in a number include all of the digits that are known with certainty, plus the first digit to the right that has an uncertain value. For example, the uncertainty in the mass of a powder sample, i.e., 3.1267g as read from an “analytical balance” is 0.0001g.In any calculation, the results are reported to the fewest significant figures (for multiplication and division) or fewest decimal places (addition and subtraction).1.Rules for deciding the number of significantfigures in a measured quantity:The number of significant figures is found by counting from left to right, beginning with the first nonzero digit and ending with the digit that has the uncertain value, e.g.,459 (3) 0.206 (3) 2.17(3) 0.00693 (3) 25.6 (3) 7390 (3) 7390. (4)(1)All nonzero digits are significant, e.g., 1.234g has 4 significant figures, 1.2 g has 2significant figures.(2)Zeroes between nonzero digits aresignificant: e.g., 1002 kg has 4 significantfigures, 3.07 mL has 3 significant figures.(3)Leading zeros to the left of the first nonzerodigits are not significant; such zeroes merelyindicate the position of the decimal point:e.g., 0.001 m has only 1 significant figure,0.012 g has 2 significant figures.(4)Trailing zeroes that are also to the right of adecimal point in a number are significant:e.g., 0.0230 mL has 3 significant figures,0.20 g has 2 significant figures.(5)When a number ends in zeroes that are notto the right of a decimal point, the zeroes arenot necessarily significant: e.g., 190 milesmay be 2 or 3 significant figures, 50,600calories may be 3, 4, or 5 significant figures.The potential ambiguity in the last rule can be avoided by the use of standard exponential, or "scientific" notation. For example, depending onwhether the number of significant figures is 3, 4, or 5, we would write 50,600 calories as:5.06 × 104 calories (3 significant figures)5.060 ×104calories (4 significant figures), or5.0600 × 104 calories (5 significant figures).2.Rules for rounding off numbers(1)If the digit to be dropped is greater than 5,the last retained digit is increased by one.For example, 12.6 is rounded to 13.(2)If the digit to be dropped is less than 5, thelast remaining digit is left as it is. Forexample, 12.4 is rounded to 12.(3)If the digit to be dropped is 5, and if anydigit following it is not zero, the lastremaining digit is increased by one. Forexample, 12.51 is rounded to 13.(4)If the digit to be dropped is 5 and isfollowed only by zeroes, the last remainingdigit is increased by one if it is odd, but leftas it is if even. For example, 11.5 is roundedto 12, 12.5 is rounded to 12.This rule means that if the digit to be dropped is 5 followed only by zeroes, the result is always rounded to the even digit. The rationale is to avoid bias in rounding: half of the time we round up, half the time we round down.3.Arithmetic using significant figuresIn carrying out calculations, the general rule is that the accuracy of a calculated result is limited by the least accurate measurement involved in the calculation.(1) In addition and subtraction, the result is rounded off to the last common digit occurring furthest to the right in all components. Another way to state this rules, is that, in addition and subtraction, the result is rounded off so that it has the same number of decimal places as the measurement having the fewest decimal places. For example,100 (assume 3 significant figures) + 23.643 (5 significant figures) = 123.643,which should be rounded to 124 (3 significant figures).(2) In multiplication and division, the resultshould be rounded off so as to have the same number of significant figures as in the component with the least number of significant figures. For example,3.0 (2 significant figures ) ×12.60 (4 significant figures) = 37.8000which should be rounded off to 38 (2 significant figures).1.4.3 Scientific NotationScientific notation, also known as standard form or as exponential notation, is a way of writing numbers that accommodates values too large or small to be conveniently written in standard decimal notation.In scientific notation all numbers are written like this:a × 10b("a times ten to the power of b"), where the exponent b is an integer, and the coefficient a is any real number, called the significant or mantissa (though the term "mantissa" may cause confusion as it can also refer to the fractional part of the common logarithm). If the number is negative then a minus sign precedes a (as in ordinary decimal notation).In standard scientific notation the significant figures of a number are retained in a factor between 1 and 10 and the location of the decimal point is indicated by a power of 10. For example:An electron's mass is about 0.00000000000000000000000000000091093822 kg. In scientific notation, this is written 9.1093822×10−31 kg.The Earth's mass is about 5973600000000000000000000 kg. In scientific notation, this is written 5.9736×1024 kg.1.5 Units of Measurement1.5.1 Systems of Measurement1.United States Customary System (USCS)The United States customary system (also called American system) is the most commonly used system of measurement in the United States. It is similar but not identical to the British Imperial units. The U.S. is the only industrialized nation that does not mainly use the metric system in its commercial and standards activities. Base units are defined butseem arbitrary (e.g. there are 12 inches in 1 foot)2.MetricThe metric system is an international decimalized system of measurement, first adopted by France in 1791, that is the common system of measuring units used by most of the world. It exists in several variations, with different choices of fundamental units, though the choice of base units does not affect its day-to-day use. Over the last two centuries, different variants have been considered the metric system. Metric units are universally used in scientific work, and widely used around the world for personal and commercial purposes. A standard set of prefixes in powers of ten may be used to derive larger and smaller units from the base units.3.SISI system (for Système International) was adopted by the International Bureau of Weights and Measures in 1960, it is a revision and extension of the metric system. Scientists and engineers throughout the world in all disciplines are now being urged to use only the SI system of units.1.5.2 SI base unitsThe SI is founded on seven SI base units for seven base quantities assumed to be mutually independent, as given in Table 1.1.Table 1.1 SI Base Physical Quantities and UnitsU n i tN a m e UnitSymbolBaseQuantityQuantitySymbolDimensionSymbolm m l l Le t e r e n g t hk i lo g r a m kgmassm Ms ec o nd stimet Ta mp e r e AelectriccurrentI Ik el v i n KthermodynTΘm i ct e m p e r a t u r em o l e molamountofsubstancen Nc an d e l a cdluminousIvJntensity1.5.3 SI derived unitsOther quantities, called derived quantities, aredefined in terms of the seven base quantities via asystem of quantity equations. The SI derived unitsfor these derived quantities are obtained from theseequations and the seven SI base units. Examples ofsuch SI derived units are given in Table 1.2, where itshould be noted that the symbol 1 for quantities ofdimension 1 such as mass fraction is generallyomitted.Table 1.2 SI Derived Physical Quantities and(symbol) Unit(symbol)UArea (A) squaremeterm V olume (V) cubicmeterm Density (ρ) kilogramper cubicmeterkVelocity (u) meterpersecondmPressure (p) pascal(Pa)kEnergy (E) joule (J) (k Frequency (ν) hertz(Hz)1Quantity of electricity (Q) coulomb(C)AElectromotive force (E) volt (V) (kmsForce (F) newton(N)kFor ease of understanding and convenience, 22SI derived units have been given special names andsymbols, as shown in Table 1.3.Table 1.3 SI Derived Units with special names andsymbolsD e r i v e dq u a n t i t y SpecialnameSpecialSymbolExpressionintermsofotherSIunitsSIbaseunitsp r r ml a n ea n g l e adianad·m-1=1s o l i da n g l e steradiansrm2·m-2=1f r e q u e n c y hertzHzs-1f o r c e newtonN m·kg·s-2p p P N mr e s s u r e ,s t r e s s ascala/m21·kg·s-2e n e r g y ,w o r k ,q u a n t i t yo fh e a jouleJ N·mm2·kg·s-2p o w e r ,r a d i a n tf l u x wattW J/sm2·kg·s-3e l e c t r i cc h a r g e q u a n t i t y coulombC s·Afe l e c t r i c i t ye l e c t r i cp o t e n t i a l ,p o t e n t i a l voltV W/Am2·kg·s-3·A-1i f f e r e n c e ,e l e c t r o m o t i v ef o r c ec a p a c i t a n c e faradF C/Vm-2·kg-1·s 4·A 2e l e c t r i cr e s i s t a n c e ohmΩV/Am2·kg·s-3·A-2e l e c t r i cc o nd u c t a n c siemensS A/Vm-2·kg-1·s2·Aem a g n e t i cf l u x weberWbV·sm2·kg·s-2·A-1m a g n e t i cf l u xd e n s i t y teslaT Wb/m2kg·s-2·A-1i n d henH Wb/m2u c t a n c e ryA ·kg·s-2·A-2C e l s i u st e m p e r a t u r e degreeCelsius°CKl u m i n o u s lumenlmcd·srcd·srl u xi l l u m i n a n c e luxlxlm/m2m-2·cd·sra c t i v i t y( o far a d i o n u c l i d e becquerelBqs-1a b s o r b e dd o se ,s p e c i f i ce n e r g y( i m p a r t e d ) ,grayGyJ/kgm2·s-2e r m ad o s ee q u i v a l e n t ,e ta l .sievertSvJ/kgm2·s-2c a t a l y t i ca c t i v i katalkats-1·molyCertain units that are not part of the SI are essential and used so widely that they are accepted by the CIPM (Commission Internationale des Poids Et Mesures) for use with the SI. Some commonly used units are given in Table 1.4.Table 1.4 Non-SI units accepted for use with theSIN a m e SymbolQuantityEquivalentSIunitmi n u t e mintime1min=6sho u r htime1h6min=36s da y dtime1d=24h=144min=864sdegreeo fa r c °planeangle1°=(π/18)radm i n u t eo fa r c ′planeangle1′=(1/6)°=(π/18radsecondo fa r c ″planeangle1″=(1/6)′=(1/36)°=(π/648)rdhect a r e haarea1ha=1a=1m²l i t r e lorLvolume1l=1dm3=.1m3ton n e tmass1t=13kg=1MgThe 20 SI prefixes used to form decimal multiples and submultiples of SI units are given in Table 1.5.Table 1.5 SI PrefixesF a c t o r NameSymbolFactorNameSymbol1 0 24yottaY 1-1decid1 0 21zettZ 1-2centc。
就人文专业和理科专业给出建议 英语作文
就人文专业和理科专业给出建议英语作文全文共5篇示例，供读者参考篇1Choosing Your Path: Humanities or Science?Hi friends! Today I want to talk to you about something really important - deciding what you want to study when you get to college. It's a big choice that can shape your whole future! There are two main paths you can take: humanities or science. Let me break it down for you.The Humanities RoadIf you decide to be a humanities major, that means you'll be studying subjects like literature, philosophy, history, and languages. Humanities is all about understanding people - how we think, what we've done in the past, the books and art we've created, and the cultures we come from.One awesome thing about humanities is you get to read loads of cool stories and books from all over the world and across time. You'll learn about ancient civilizations like the Egyptians, Greeks and Romans. You'll dive into epic tales like The Odyssey and analyze poems from greats like Shakespeare. It'slike going on amazing adventures without ever leaving your classroom!Another fun part is getting to discuss and debate big questions that have puzzled humans for centuries. What is truth? What makes a just society? Why do we behave the way we do? You get to explore your deepest thoughts and hear all kinds of fascinating perspectives.With a humanities degree, you could go on to be a writer, teacher, journalist, lawyer, researcher, diplomat, and tons of other careers. The key skills you build are communication, critical thinking, research, and understanding different cultures and viewpoints. Those are super useful for lots of jobs!The Science PathNow let's talk about the science route. If you pick this path, you'll be immersed in fields like biology, chemistry, physics, computer science, and mathematics. Science is all about logically studying the natural world through observation and experimentation.One of the best parts of science is getting to do awesome hands-on experiments and activities. You might get to dissect afrog, model the planets' orbits, or design your own video game. It's way more fun than just reading from textbooks.Science also lets you unlock the mysteries of how things work - from the tiniest atoms to the vast universe. You'll learn about incredible discoveries like gravity, evolution, black holes, and more. Who knows, you might even get to make the next big breakthrough someday!Careers in science are really varied and exciting. You could be a doctor finding cures for diseases, an engineer building cool new tech, a programmer creating video games, an astronaut exploring space, or a researcher protecting endangered animal species. The possibilities are endless when you understand how the world operates.The Tricky ChoiceSo those are the two main scholastic roads you can travel in college. But how do you decide which one is right for you? Well, I'd say look at your personal interests and strengths.If you're a creative person who loves art, music, and literature, humanities could be an excellent fit. You'll get to express yourself through writing, analyze hidden meanings, and discuss human behavior.But if you're more of a logical, analytical thinker who has always been fascinated by the natural world, a science major might be more your style. You'll get to run experiments, build things, and uncover the laws that govern our universe.The awesome thing is, you don't have to pick just one path. These days, lots of students double major or take a mix of humanities and science classes. That allows you to build a ton of diverse skills and knowledge.Just Explore!My main advice? Don't stress too much about your decision right now. When you get to college, take a bunch of different classes to get a taste for what each subject is like. Talk to your professors and older students about potential careers. And go with your passion - choose the major that truly excites and inspires you.At the end of the day, both humanities and science offer amazing opportunities to learn, create, and make a difference in the world. Just study what you love and have fun on your educational journey! I know you all are going to do great things.篇2Choosing What to Study in CollegeHi friends! Have you ever thought about what you might want to study when you go to college someday? It's a big decision with lots of different options. Today I'll tell you about two main paths you can take: humanities or sciences. They are both super interesting in their own ways!The HumanitiesLet's start with the humanities. These are subjects that study people - how we think, what we've done throughout history, the languages we speak, the stories we tell, and more. Some examples of humanity majors are:HistoryYou get to learn all about the past! How did ancient civilizations live? What were the biggest wars and discoveries? Who were the important leaders and innovators? If you love learning stories from long ago, history could be for you.EnglishThis is the study of literature like novels, poetry, plays and more. You read a lot of books and analyze what the author was trying to say. English majors learn great writing and communication skills.PhilosophyHave you ever wondered about the big questions in life? Like what is the meaning of existence? What is truth? How can we define right from wrong? Philosophers think deeply about these kinds of ideas.Foreign LanguagesThe world has thousands of languages besides English! In this major, you can become an expert in another tongue like Spanish, French, Mandarin Chinese or Arabic. You'll learn to speak, read and write in that language fluently.The SciencesOn the other hand, you could go into a scientific field of study. These focus more on the natural world, using math, research and experiments. Popular science majors include:BiologyThis is the study of living things like plants, animals and humans. You'll learn about cells, ecosystems, genetics and more. Biologists get to do lots of cool experiments and lab work.ChemistryDo you love mixing together chemicals and watching reactions happen? That's what chemists do! They analyzedifferent substances, their structures and properties. Chemistry helps create new materials and medicines.PhysicsHave you ever wondered about the fundamental laws that govern the entire universe? That's what physics seeks to understand - things like energy, force, motion and gravity. You need to be a whiz at math for this one!Computer ScienceWith this major, you learn all about designing software, writing code and developing apps and programs. Our world runs on computers now, so these skills are super valuable. You get to build cool tech!EngineeringFrom bridges to skyscrapers to robots, engineers design and build the amazing creations that make modern life possible. There are many specialties like civil, mechanical, electrical and more.Both paths have pros and cons. The humanities let you study the depths of human experience and culture. But the sciences explore the phenomena that make our physical world work. Either way, you'll gain important skills!At the end of the day, you should follow your passion and genuine interests. Are you someone who loves reading, writing and exploring ideas? A humanity could be great. But if you're a math whiz who likes hands-on experiments, go for a science. The choice is yours!Personally, I find both realms fascinating in their own ways. I'm really interested in archaeology and anthropology which blend humanities and science by studying ancient peoples and cultures. But I also love learning about topics like evolution, astronomy and robotics. There's so much amazing knowledge to gain from both sides!The awesome part is that you don't have to pick just one path. Many students double major or take a variety of courses across disciplines. That way you can feed all of your different intellectual curiosities. College is a feast for your brain!I know this is a long way off for you right now. But it's never too early to start thinking about the future! Pay attention to what topics really stimulate your mind and creativity in school. Ask your parents, teachers and older friends about their experiences too. Keeping an open mindset will help guide you in the right direction.Just remember that there is no single "best" field of study. Every subject has its own value and importance in this big, complex world. Whether you end up pursuing the classics of ancient Greece, curing deadly diseases, designing new green technologies or anything else, you'll be making a positive impact. The most important thing is that you follow your genuine passions wholeheartedly. Embrace your natural gifts and curiosities!Picking a college major doesn't seal your entire fate in life either. My mom studied English in school, but now she's a marketing executive. My uncle was pre-med but ended up running his own gardening business. You can always change paths down the road too. The knowledge and skills you gain will serve you well wherever you end up.For now, just soak in as much learning as you can from all different subjects. This will prepare you to make the best decision for yourself when that time comes. Don't put too much pressure on your young self! Enjoy exploring all the awesome areas of human inquiry while you can. The future is full of exciting possibilities. I can't wait to see what you all will achieve!篇3Choosing Your Major: Humanities or Science?Hi friends! Today I want to talk to you about something super important - choosing what you'll study in college. It's a really big decision that can affect your whole future! There are a lot of different paths you can take, but I'll focus on two main ones: humanities and science.Let's start with humanities. These are subjects like literature, philosophy, history, and languages. If you choose a humanity major, you'll spend a lot of time reading, writing essays, discussing ideas, and learning about people and cultures from the past and present.Reading and writing may not sound like a lot of fun. But humanities classes are actually pretty cool! You get to read fascinating stories, poems, and plays. You analyze deep questions about life, morality, and society. And you learn how to express your thoughts clearly and persuasively. Those skills are useful for any career!Some people think humanities are just a bunch of outdated, irrelevant information. But I disagree! Understanding history and culture helps us make sense of the world today. It teaches us about different perspectives and ways of thinking. With ahumanities background, you'll be prepared for lots of jobs like teaching, journalism, law, business, and public service.On the other hand, science is all about exploring the natural world through observation and experimentation. If you pick a science major like biology, chemistry, or physics, you'll spend tons of time in labs running experiments, analyzing data, and testing theories.I know what you're thinking - hours of lab work sounds exhausting! But trust me, doing hands-on science activities is a blast. You get to look through microscopes, mix chemicals, build models, and more. Science is all about discovering how things work and finding solutions to problems. Pretty awesome, right?People sometimes say science is dry and boring. Those people are just wrong! Science is an endless world of curiosity and amazement. Every new discovery opens up more mysteries to explore about our universe, our planet, our bodies, and our technology. With science knowledge, you could have an exciting career in fields like medicine, engineering, computer science, or research.So those are the two paths in a nutshell. But how do you pick between them? My advice is to think hard about your interests, strengths, and goals.If you're a creative person who loves art, music, andself-expression, humanities could be great for you. If you have a passion for justice, public policy, or cultural understanding, a humanities path may be very rewarding.But if you've always been curious about the natural world and have a brain for math and problem-solving, science is probably the way to go. A science degree can open doors to using cutting-edge technology and making ground-breaking innovations.Of course, you don't have to pick one path or the other! These days, many people study a mix of humanities and sciences. Maybe you'll be a genetic counselor who studied biology and ethics. Or an environmental lawyer who focused on policy and ecology. Or a computer programmer with an artistic side who creates beautiful software and video games. The possibilities are endless when you combine different areas of study!No matter what you choose, the most important things are to follow your interests and work hard. Don't just pick a major because it sounds prestigious or high-paying. Find something you're genuinely excited about learning. If you pursue your passions, you'll be much more motivated in school and satisfied in your future career.Well, those are my thoughts! I know deciding on a major seems tough. But try not to stress too much about it right now. You've got many years ahead to figure out the perfect path. For now, focus on exploring different subjects, having fun, and keeping an open mind. Before you know it, you'll discover the field that lets you pursue your dreams while making a positive impact on the world.Thanks for listening, and good luck deciding between humanities and science! Just remember that with hard work and determination, you can excel at whichever route you take. Study what you love, and you'll go far!篇4Title: Picking a College Major - Humanities or Science?Hi friends! Today I want to talk about something really important - choosing what to study in college. There are so many cool subjects to pick from. It can be confusing and scary trying to decide. But don't worry, I'm here to help!The two main paths are humanities majors and science majors. Humanities are subjects like English, history, philosophy, and art. Science majors focus on stuff like math, biology,chemistry, and physics. Both paths are awesome in their own ways. Let me break it down for you:ities MajorsThese are my personal favorites! With a humanities major, you get to read fascinating books, discuss big ideas, and learn about different cultures and time periods. It's like going on awesome adventures through pages of a book or museum exhibits.If you pick an English major, you'll read classics like Harry Potter and analyze what the author's deeper meanings were. You can take creative writing classes to write your own stories too! For a history major, you'll learn about ancient civilizations, wars, leaders, and how the past shaped the world we live in today. It's like being a time traveler. Philosophy lets you ponder mindboggling questions like "What is the meaning of life?"Art classes let your creative side shine by painting, sculpting, or taking beautiful photographs. And if you're into music, you can study that too by analyzing lyrics, musical periods, and composing your own melodies. There are so many fun options!The coolest part about humanities is you get to use your imagination and creative thinking skills a ton. You'll write loads of essays and papers to practice communicating your thoughts clearly. Public speaking is big too - getting comfy discussingyour ideas in front of others. Don't worry, it gets easier with practice!After college, humanities grads can pursue careers like teaching, writing, law, business, advertising, public relations, politics, and more. The skills you gain like communication, critical thinking, and analysis are super useful for any job.Science MajorsIf you're more of a math and science whiz kid, then maybe a science major is calling your name! With these majors, you'll get to do lots of experiments, analyze data, and explore the laws that govern our universe.As a biology major, you might get to examine real human cells under a microscope or learn anatomy by studying actual specimens (so cool, but kinda gross!). Chemistry will let you mix different compounds together and see how they react - maybe you'll accidentally create a new silly putty formula! Physics and astronomy are amazing for exploring mind-blowing concepts about space, time, energy, and the origins of our universe.Math is the universal language that underlies all the sciences. If you go down this path, get ready to solve a ton of equationsand problem sets. It'll feel like cracking secret codes as you apply formulas to predict patterns and trends.Science is very hands-on with lots of labs and experiments. You'll learn to make careful observations, record data precisely, and form hypotheses to test. Having patience and curiosity is a must, because understanding the natural world takes rigorous trial-and-error.After graduating, science degrees lead to careers like doctor, researcher, engineer, computer programmer, environmental scientist, and more. Science is everywhere in our modern world, so these majors stay in high demand.The Winning Path?So which major reigns supreme - humanities or science? In my opinion, you can't go wrong with either! They both develop critical skills that'll help you succeed no matter what career you pursue.Humanities sharpen your imagination, communication abilities, and appreciation for culture. Science builds your logic, problem-solving, and understanding of our physical world. A nice balanced education covers both areas.The most important thing is to pick a major that you're genuinely excited about and curious to learn more on the subject. It'll be way easier to stay motivated and do well in classes you actually enjoy. Don't just choose something because your parents or friends pressure you.At the end of the day, both humanities and science play vital roles in our society. We need creative thinkers and brilliant innovators to keep progressing as a species. The world needs all kinds of minds working together!If you still can't decide between the two paths, here's my advice: Make a list of your favorite high school subjects and activities. Did you love reading books and writing essays? Humanities may be calling. Or if you lived for science fairs and math competitions, lean into that science strength. You can't go wrong feeding your natural talents and interests.Most colleges let you sample a variety of classes your first year or two before declaring a major too. Use that time to explore different subjects and see what clicks best. Don't stress if you change your mind - lots of students end up switching majors as their passions evolve.Just remember to choose a path that excites you. College is a fresh start to dive deeper into the topics that make you say"WOW, that's so cool!" Whether it's deconstructing ancient literature or uncovering mysteries of the universe, dedicate yourself to what sparks your curiosity and joy. The rest will follow.I hope these insights help as you look ahead to college! Don't be afraid to follow your biggest interests and wildest academic dreams. Humanities or science, both are amazing journeys. Just make sure you navigate the one that feels right for you. This decision lays the foundation for your future studies and career - have fun with it!Let me know if you have any other questions. I'm rooting for you to find a major you absolutely love.Your friend,[Your name]篇5Choosing Your Major: Humanities or Science?Hi friends! Today I want to talk to you about something really important - choosing what you'll study in university. It's a big decision that can impact your whole future! When I was your age, I didn't know much about the different kinds of majors. Butnow that I'm a wise 5th grader, I've learned a ton. Let me share my knowledge with you!There are two main paths you can take in university - humanities or science. The humanities includes subjects like history, English literature, philosophy, and languages. Science is all about chemistry, physics, biology, and math. Both paths are super cool and important in their own ways.Let's start with humanities. If you love reading books, writing stories, and learning about how people lived in the past, humanities could be perfect for you! People who study humanities tend to be really creative and have amazing imaginations. They learn to think critically about big ideas and express themselves clearly through writing and speaking.My friend Jessica is majoring in English because she's obsessed with Shakespeare's plays. She spends hours analyzing all the hidden meanings and metaphors in his writing. I have to admit, I get kinda bored when she starts ranting about symbolism and stuff. But she's just so passionate about it!Another option in humanities is history. I'm honestly not a huge fan because I find memorizing dates and names of dead people pretty dull. But my buddy Marcus is a total history nut! He knows everything about World War 2, ancient Egypt, you name it.He says studying history helps you understand why the world is the way it is today. It teaches you about different cultures and how society has evolved over time. Pretty interesting when you think about it that way!If you go the humanities route, you'll probably take a bunch of classes where you read difficult books and have to write a million essays. It's a lot of work, but you get to explore really cool topics like art, literature, religion and philosophy. You'll learn to think critically, communicate well, and see things from multiple perspectives.On the flip side, you could choose to pursue a science major like biology, chemistry, physics or math. This path is radically different from humanities but just as awesome! Instead of reading ancient texts, you'll be doing experiments in a lab, analyzing data, and learning about how the natural world works.My older brother is a biology major and he's always showing me gross photos of animals being dissected. I have to cover my eyes - I can't stand the sight of blood and guts! But if you're really interested in living creatures from microscopic bacteria to huge elephants, biology lets you study them in-depth.For the math and science whizzes out there, disciplines like physics, chemistry, and engineering could be great fits. You'lltake a ton of intense math classes and learn all about formulas, equations, molecules and forces of nature. It's not for the faint of heart - you have to be a critical thinker who loves solving complex problems. But if you stick with it, you could get a sweet job designing video games, building bridges, or even sending rockets into space! How cool is that?No matter which direction you go, expect to work insanely hard. Both humanities and science require serious brainpower and commitment. In humanities, you'll write what feels like a million papers analyzing poems, books, and historical documents. For science, get ready to pull a lot of all-nighters studying for exams on topics like calculus and organic chemistry that'll make your head spin.So how do you decide which path is right for you? Think about your interests, strengths, and natural abilities. Do you have a vivid imagination and love getting lost in a good book? Humanities could be your calling. Are you a concrete thinker who's fascinated by the natural world and likes dealing with hard facts? A science major might be more up your alley.The great thing is, you don't have to pick your major right away as a freshman. Most universities let you take a variety of classes to explore your interests before declaring a major after ayear or two. That gives you time to figure out what inspires your passion.At the end of the day, there's no objectively "better" choice between humanities and science. Both areas are crucial to understanding our world and solving global issues. We need poets and philosophers just as much as biologists and engineers. The most important thing is studying something you're genuinely excited about. When you love what you're learning, it won't feel like work.So keep an open mind, work hard, and follow your unique talents and curiosities. The sky's the limit when it comes to what you can achieve, whether your path leads to writing the next great American novel or mapping the human genome. Oh, and don't stress too much - you've got plenty of time to decide. Just have fun exploring! Let me know if you have any other questions.。
14-WhatDoAnalyticalChemistsDo
14-WhatDoAnalyticalChemistsDoAnalytical chemistry is concerned with the chemical characterization of matter and the answers to two important questions:what is it (qualitative) and how much is it (quantitative). Chemicals make up everything we use or consume, and knowledge ofthe chemical composition of many substances is important in our daily lives. Analytical chemistry plays an important role in nearly all aspects of chemistry, for example, agricultural, clinical, environmental, forensic, manufacturing, metallurgical, and pharmaceutical chemistry. The nitrogen content of a fertilizer determines its value. Foods must be analyzed for contaminants (e.g., pesticide residues) and for essential nutrients (e.g. vitamin content). The air in cities must be analyzed for carbon monoxide. Blood glucose must be monitored in diabetics (and, in fact, most diseases are diagnosed bychemical analysis). The presence of trace elements from gun powder on a murder defendant's hand will prove a gun was fired.The quality of manufactured products often depends on proper chemical proportions, and measurement of the constituents is anecessary part of quality control. The carbon content of steel will determine its quality. The purity of drugs will determine their efficacy.What is Analytical Science?The above description of analytical chemistry provides an overview of the discipline of analytical chemistry. There havebeen various attempts to more specifically define the discipline. The late Charles N. Reilley said: "Analytical chemistry iswhat analytical chemists do." The discipline has expanded beyond the bounds of just chemistry, and many have advocated usingthe name analytical science to describe the field. This term is used in a National Science Foundation report from workshops on “Curricular Developments in the Analytical Sciences.” Even this term falls short of recognition of the role of instrumentation development and application. One suggestion is that we use the term analytical science and technology.The Federation of European Chemical Societies held a contest to define analytical chemistry, and the following suggestionby K. Cammann was selected.Analytical chemistry provides the methods and tools needed for insight into our material world ... for answering four basic questions about a material sample:● What?● Where?● How much?● What arrangement, structure or form?The Division of Analytical Chemistry of the American Chemical Society provides a comprehensive definition of analyticalchemistry, which may be found on their website. It is reproduced in most part here:Analytical chemistry seeks ever improved means ofmeasuring the chemical composition of natural and artificial materials.The techniques of this science are used to identify the substances which may be present in a material and to determine theexact amounts of the identified substance.Analytical chemists work to improve thereliability of existing techniques to meet the demands for better chemicalmeasurements which arise constantly in our society. They adopt proven methodologies to new kinds of materials or to answernew questions about their composition and their reactivity mechanisms. They carry out research to discover completely new principles of measurement and are at the forefront of the utilization of major discoveries, such as lasers and microchip devices for practical purposes. Their efforts serve the needs of many fields:In medicine, analytical chemistry is the basis for clinical laboratory tests which help physicians diagnose disease and chart progress in recovery.In industry, analytical chemistry provides the means of testing raw materials and for assuring the quality offinished products whose chemical composition is critical. Many household products, fuels, paints, pharmaceuticals, etc.are analyzed by the procedures developed by analytical chemists before being sold to the consumer.Environmental quality is often evaluated by testing for suspected contaminants using the techniques of analytical chemistry.The nutritional value of food is determined by chemical analysis for major components such as protein andcarbohydrates and trace components such as vitamins and minerals. Indeed, even the calories in a food are often calculated from its chemical analysis.Analytical chemists also make important contributions to fields as diverse as forensics, archaeology, and space science.Qualitative and Quantitative Analyses: What Does Each Tell Us?The discipline of analytical chemistry consists of qualitative analysis and quantitative analysis. The former deals with the identification of elements, ions, or compounds present in a sample (we may be interested in whether only a givensubstance is present), while the latter deals with the determination of how much of one or more constituents is present. Thesample may be solid, liquid, gas, or a mixture. The presence of gunpowder residue on a hand generally requires only qualitative knowledge, not of how much is there, but the price of coal will be determined by the percentage of sulfur impurity present.Qualitative tests may be performed by selective chemical reactions or with the use of instrumentation. The formation ofa white precipitate when adding a solution of silver nitrate to a dissolved sample indicates the presence of chloride.Certain chemical reactions will produce colors to indicate the presence of classes of organic compounds, for example, ketones. Infrared spectra will give “fingerprints” of organic compounds or their functional groups.A clear distinction should be made between the termsselective and specific:● A selective reaction or test is one that can occur with other substances but exhibits a degree of preference for the substance of interest.● A specific reaction or test is one that occurs only with thesubstance of interest.Unfortunately, few reactions are specific but many exhibit selectivity. Selectivity may be achieved by a number of strategies.Some examples are:●Sampl e preparation (e.g., extractions, precipitation)●Instrumentation (selective detectors)●Target analyte derivatization (e.g., derivatize specific functional groups with detecting reagents)●Chromatography, which provides powerful separationFor quantitative analysis, a history of the sample composition will often be known (it is known that blood containsglucose), or else the analyst will have performed a qualitative test prior to performing the more difficult quantitative analysis. Modern chemical measurement systems often exhibit sufficient selectivity that a quantitative measurement can alsoserve as a qualitative measurement. However, simple qualitative tests are usually more rapid than quantitative procedures.Qualitative analysis is composed of two fields: inorganic and organic. The former is usually covered in introductory chemistry courses, whereas the latter is best left until after the student has had a course in organic chemistry.In comparing qualitative versus quantitative analysis, consider, for example, the sequence of analytical proceduresfollowed in testing for banned substances at the Olympic Games. The list of prohibited substances includes about 500 different active constituents: stimulants, steroids, beta-blockers, diuretics, narcotics, analgesics, local anesthetics, and sedatives. Some are detectable only as their metabolites. Many athletes must be tested rapidly, and it is not practical to perform a detailed quantitative analysis on each. There are three phases in the analysis: the fast-screening phase, the identification phase, and possible quantification phase. In the fast-screening phase, urine samples are rapidly tested for the presence of classes of compounds that will differentiate them from “normal” samples. Variou s techniques include immunoassays, gas chromatography, and liquid chromatography. About 5% of the samples may indicate the presence of unknowncompounds that may or may not be prohibited but need to be identified. Samples showing a suspicious profile during the screening undergo a new preparation cycle (possible hydrolysis, extraction, derivatization), depending on the nature of thecompounds that have been detected. The compounds are then identified using the highly selective combination of gas chromatography/mass spectrometry (GC/MS). In this technique, complex mixtures are separated by gas chromatography, and theyare then detected by mass spectrometry, which provides molecular structural data on the compounds. The MS data, combined withthe time of elution from the gas chromatograph, provide a high probability of the presence of a given detected compound.GC/MS is expensive and time-consuming, and so it is used only when necessary. Following the identification phas e, somecompounds must be precisely quantified since they may normally be present at low levels, for example, from food, pharmaceutical preparations, or endogenous steroids, and elevated levels must be confirmed. This is done using quantitativetechniques such as spectrophotometry or gas chromatography.。
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measurements which arise constantly in our society. They adopt proven methodologies to new kinds of materials or to answer
Analytical chemistry is concerned with the chemical characterization of matter and the answers to two important questions:
what is it (qualitative) and how much is it (quantitative). Chemicals make up everything we use or consume, and knowledge of
by K. Cammann was selected.
Analytical chemistry provides the methods and tools needed for insight into our material world ... for answering four
are analyzed by the procedures developed by analytical chemists before being sold to the consumer.
? Environmental quality is often evaluated by testing for suspected contaminants using the techniques of analytical
basic questions about a material sample:
● What?
● Where?
● How much?
● What arrangement, structure or form?
The Division of Analytical Chemistry of the American Chemical Society provides a comprehensive definition of analytical
devices for practical purposes. Their efforts serve the needs of many fields:
? In medicine, analytical chemistry is the basis for clinical laboratory tests which help physicians diagnose disease
from its chemical analysis.
Analytical chemists also make important contributions to fields as diverse as forensics, archaeology, and space science.
the name analytical science describe the field. This term is used in a National Science Foundation report from workshops
on “Curricular Developments in the Analytical Sciences.” Even this term falls short of recognition of the role of
new questions about their composition and their reactivity mechanisms. They carry out research to discover completely new
principles of measurement and are at the forefront of the utilization of major discoveries, such as lasers and microchip
the chemical composition of many substances is important in our daily lives. Analytical chemistry plays an important role in
nearly all aspects of chemistry, for example, agricultural, clinical, environmental, forensic, manufacturing, metallurgical,
and pharmaceutical chemistry. The nitrogen content of a fertilizer determines its value. Foods must be analyzed for
contaminants (e.g., pesticide residues) and for essential nutrients (e.g. vitamin content). The air in cities must be
instrumentation development and application. One suggestion is that we use the term analytical science and technology.
The Federation of European Chemical Societies held a contest to define analytical chemistry, and the following suggestion
sample may be solid, liquid, gas, or a mixture. The presence of gunpowder residue on a hand generally requires only
The techniques of this science are used to identify the substances which may be present in a material and to determine the
exact amounts of the identified substance.
and chart progress in recovery.
? In industry, analytical chemistry provides the means of testing raw materials and for assuring the quality of
finished products whose chemical composition is critical. Many household products, fuels, paints, pharmaceuticals, etc.
analyzed for carbon monoxide. Blood glucose must be monitored in diabetics (and, in fact, most diseases are diagnosed by
chemical analysis). The presence of trace elements from gun powder on a murder defendant's hand will prove a gun was fired.
The quality of manufactured products often depends on proper chemical proportions, and measurement of the constituents is a
necessary part of quality control. The carbon content of steel will determine its quality. The purity of drugs will determine
been various attempts to more specifically define the discipline. The late Charles N. Reilley said: "Analytical chemistry is
what analytical chemists do." The discipline has expanded beyond the bounds of just chemistry, and many have advocated using
chemistry.
? The nutritional value of food is determined by chemical analysis for major components such as protein and
carbohydrates and trace components such as vitamins and minerals. Indeed, even the calories in a food are often calculated
the identification of elements, ions, or compounds present in a sample (we may be interested in whether only a given