A Comparison of the Electron and Ion Irradiation Effects on the：在电子和离子束辐照效应的比较

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摘录不饱和聚酯文献中的经典句子

1.To access the description of a composite material, it will be necessary to specify the nature of components and their properties, the geometry of the reinforcement, its distribution, and the nature of the reinforcement–matrix interface.2. However, most of them are not chemically compatible with polymers3. That’s why for many years, studies have been conducted on particles functionalization to modulate the physical and/or chemical properties and to improve the compatibility between the ﬁller and the matrix [7].4. Silica is used in a wide range of products including tires, scratch-resistant coatings, toothpaste,medicine, microelectronics components or in the building5. Fracture surface of test specimens were observed by scanning electron microscopy6.Test specimens were prepared by the following method from a mixture composed with 40 wt% UPE, 60 wt% silica Millisil C6 and components of ‘‘Giral.’7.Grafted or adsorbed component amounts on modiﬁed silica samples were assessed by thermogravimetric analysis (TGA) using a TGA METTLER-TOLEDO 851e thermal system. For the analysis, about 10–20 mg of samples were taken and heated at a constant rate of 10 C/min under air (purge rate 50 mL/min) from 30 to 1,100 C.8.Nanocomposites with different concentrations of nanofibers wereproduced and tested, and their properties were compared with those of the neat resin.9.Basically, six different percentages were chosen, namely 0.1, 0.3, 0.5, 1, 2, 3 wt %.10.TEM images of cured blends were obtained with a Philips CM120 microscope applying an acceleration voltage of 80 kV.Percolation threshold of carbon nanotubes ﬁlled unsaturated polyesters 11.For further verification, the same experiment was carried out for the unmodified UP resin, and the results showed that there were no endothermic peaks12.The MUP resin was checked with d.s.c, scanning runs at a heating rate of 10°C min 1. Figure 4a shows that an endothermic peak appeared from 88 to 133°C, which indicates bond breaking in that temperature range.13.On the basis of these results, it is concluded that a thermally breakable bond has been introduced into the MUP resin and that the decomposition temperature is around I lO°C.14.The structures of the UP before and after modification were also checked with FTi.r. Figure 5 shows a comparison of the i.r. spectra of the unmodified and modified UP resins.15This is probably a result of the covalent bonding ofthe urethane linkage being stronger than the ionic bondingof MgO.16.These examples show that different viscosity profiles can be designed with different combinations of the resins and thickeners according to the needs of the applications.17. A small secondary reaction peak occurred at higher temperatures, probably owing to thermally induced polymerization. 18.Fiber-reinforced composite materials consist of ﬁbers of high strength and modulus embedded in or bonded to a matrix with a distinct interfaces between them.19.In this form, both ﬁbers and ma-trix retain their physical and chemical identities,yet they provide a combination of properties that cannot be achieved with either of the constituents acting alone.20.In general, ﬁbers are the principal load-bearing materials, while the surrounding matrix keep them in the desired location, and orientation acts as a load transfer medium between them and protects them from environmental damage.21.Moreover, both the properties, that is,strength and stiffness can be altered according to our requirement by altering the composition of a single ﬁber–resin combination.22.Again, ﬁber-ﬁlled composites ﬁnd uses in innumerable applied ar- eas by judicious selection of both ﬁber and resin.23.In recent years, greater emphasis has been rendered in the development of ﬁber-ﬁlled composites based on natural ﬁbers with a view to replace glass ﬁbers either solely or in part for various applications. 24.The main reasons of the failure are poor wettability and adhesion characteristics of the jute ﬁber towards many commercial synthetic resins, resulting in poor strength and stiffness of the composite as well as poor environmental resistance.25.Therefore, an attempt has been made to overcome the limitations of the jute ﬁber through its chemical modiﬁcation.26.Dynamic mechanical tests, in general, give more information about a composite material than other tests. Dynamic tests, over a wide range of temperature and frequency, are especially sensitive to all kinds of transitions and relaxation process of matrix resin and also to the morphology of the composites.27.Dynamic mechanical analysis (DMA) is a sensitive and versatile thermal analysis technique, which measures the modulus (stiffness) and damping properties (energy dissipation) of materials as the materials are deformed under periodic stress.28.he object of the present article is to study the effect of chemical modiﬁcation (cyanoethylation)of the jute ﬁber for improving its suitability as a reinforcing material in the unsaturated polyesterres in based composite by using a dynamic mechanical thermal analyzer.30.General purpose unsaturated polyester resin(USP) was obtained from M/S Ruia Chemicals Pvt. Ltd., which was based on orthophthalic anhydride, maleic anhydride, 1,2-propylene glycol,and styrene.The styrene content was about 35%.Laboratory reagentgrade acrylonitrile of S.D.Fine Chemicals was used in this study without further puriﬁcation. 31.Tensile and ﬂexural strength of the ﬁbers an d the cured resin were measured by Instron Universal Testing Machine (Model No. 4303).32.Test samples (60 3 11 3 3.2 mm) were cut from jute–polyester laminated sheets and were postcured at 110°C for 1 h and conditionedat 65% relative humidity (RH) at 25°C for 15 days.33.In DMA, the test specimen was clamped between the ends of two parallel arms, which are mounted on low-force ﬂexure pivots allowing motion only in the horizontal plane. The samples in a nitrogen atmosphere were measured in the ﬁxed frequency mode, at an operating frequency 1.0 HZ (oscillation amplitude of 0.2 mm) and a heating rate of 4°C per min. The samples were evaluated in the temperature range from 40 to 200°C.34.In the creep mode of DMA, the samples were stressed for 30 min at an initial temperature of 40°C and allowed to relax for 30 min. The tem- perature was then increased in the increments of 40°C, followed by an equilibrium period of 10min before the initiation of the next stress relax cycle. This program was continued until it reached the temperature of160°C. All the creep experiments were performed at stress level of20 KPa (approximate).35.The tensile fracture surfaces of the composite samples were studied with a scanning electron microscope (Hitachi Scanning electron Microscope, Model S-415 A) operated at 25 keV.36.The much im proved moduli of the ﬁve chemically modiﬁed jute–polyester composites might be due to the greater interfacial bond strength between the ma trix resin and the ﬁber.37.The hydrophilic nature of jute induces poor wettability and adhesion characteristics with USP resin, and the presence of moisture at the jute–resin interface promotes the formation of voids at the interface. 38.On the other hand, owing to cyanoethylation, the moisture regain capacity of the jute ﬁber is much reduced; also, the compatibility with unsaturated polyester resin has been improved and produces a strong interfacial bond with matrix resin and produces a much stiffer composite.39.Graphite nanosheets(GN), nanoscale conductive ﬁller has attracted signiﬁcant attention, due to its abundance in resource and advantage in forming conducting network in polymer matrix40.The percolation threshold is greatly aﬀected by the properties of the ﬁllers and the polymer matrices,processing met hods, temperature, and other related factors41.Preweighted unsaturated polyester resin and GN were mixed togetherand sonicated for 20 min to randomly disperse the inclusions.42.Their processing involves a radical polymerisation between a prepolymer that contains unsaturated groups and styrene that acts both asa diluent for the prepolymer and as a cross-linking agent.43.They are used, alone or in ﬁbre-reinforced composites, in naval constructions, offshore applications,water pipes, chemical containers, buildings construction, automotive, etc.44.Owing to the high aspect ratio of the ﬁllers, the mechanical, thermal, ﬂame retardant and barrier properties of polymers may be enhanced without a signiﬁcant loss of clarity, toughness or impact strength.45.The peak at 1724 cm-1was used as an internal reference, while the degree of conversion for C=C double bonds in the UP chain was determined from the peak at 1642 cm-1and the degree of conversion for styrene was calculated through the variation of the 992 cm-1peak46. Paramount to this scientific analysis is an understanding of the chemorheology of thermosets.47．Although UPR are used as organic coatings, they suffer from rigidity, low acid and alkali resistances and low adhesion with steel when cured with c onventional ‘‘small molecule’’ reagents.48．Improvements of resin ﬂexibility can be obtained by incorporating long chain aliphatic com-pounds into the chemical structure of UPR. 47．In this study, both UPR and hardeners were based on aliphatic andcycloaliphatic systems to produce cured UPR, which have good durability with excellent mechan-ical properties.50．UPR is one of the widely used thermoset polymers in polymeric composites, due to their good mechanical properties and relatively inexpensive prices.51．[文档可能无法思考全面，请浏览后下载，另外祝您生活愉快，工作顺利，万事如意!]。

Pyridine-N-Oxide

Conclusions
Tributyl citrate, trihexyl citrate, and tributyl aconitate have been produced in the continuous esterification equipment described herein. Contact times of 2 to 3 minutes resulted in conversions of better than 99%. These times may he compared with a usual run length of 24 hours in a commercial unit. At temperatures greatly above those employed in industry (200" C.), there was no measurable decomposition of citric acid. I n addition, the tributyl citrate produced was of high quality, superior to the commercial product. The trihexyl citrate produced was also of high quality and had a much better color than the commercial product. It is evident from this work that a continuous process for the esterification of polycarboxylic acids is feasible. I n order to design a commercial unit, however, additional work on a larger size unit would have t o be done.

等离子体鞘层(PPT-78)

ni ns const
-V0
负脉冲高压电源
dE dx
4ens
E(x) 4ens x
(x) 2ens x2
1/ 2
s
lDe
2V0 Te
Linear electric fielld Sheath thickness
(b) Child law-sheath In the steady state, the ion-matrix sheath is not self-
Plasma potential
3、直流偏压鞘层
在一些等离子体工艺中，通常在基片或靶上施加直流负偏压，如物理气相沉积（溅射）合成薄膜工艺。
离子
直流偏压电源溅射靶
基片
鞘层模型 (与悬浮鞘层的基本方程相同）：
ni ( x )ui ( x ) n0u0
1 2
M i ui2 ( x )
e( x)
Chinese Phys. Lett., 17, 586 (2000); Thin Solid Films 390, 107 (2001); Int. J. Mod. Phys B 16, 1120（2002）
(a) 沉积偏压为-60V
(b) 沉积偏压为-160V
偏压对N-C薄膜的表面形貌的影响
Deposition rate (nm/s)
d dx
(M
iu
2
/
2)
e
d dx
M
iu
其中是离子与中性粒子的电荷交换碰撞频率。
碰撞效应对Child law 的影响？
4、负脉冲偏压鞘层
Why use the pulse bias-voltage?
在合成绝缘膜工艺中, 为了有效地中和缘靶表面的电荷积累, 通常靶表面上施加约1千伏左右的负脉冲偏压。特别是在Plasma Source Ion Implantation (PSII)工艺中，负脉冲偏压可高达几十千伏。

cl-和br-离子半径

cl-和br-离子半径Cl- and Br- are both halogen ions and they share some similar properties, including their ionic radii. The ionic radius of an ion is the measure of the size of the ion, and it plays an important role in determining the chemical and physical properties of the ion.The ionic radius of an ion is defined as the distance from the nucleus to the outermost electron shell of the ion. It is important to note that ionic radii are difficult to measure precisely, as they can change depending on the ion's environment and charge. However, there are some standard values that have been determined through various experimental methods.The ionic radius of Cl- is approximately 181 picometers (pm), while the ionic radius of Br- is approximately 196 pm. This means that the ionic radius of Br- is larger than that of Cl-, which is consistent with their positions in the periodic table. As one moves down a group in the periodic table, the atomic radius increases, and this is reflected in the size of the ions as well.The differences in the ionic radii of Cl- and Br- have implications for their chemical and physical properties. For example, the larger size of Br-means that it has a lower charge density compared to Cl-. This can affect the ability of the ions to attract other ions or molecules, as well as their solubility in various solvents.In terms of chemical reactivity, the larger size of Br- means that it is less electronegative compared to Cl-. Electronegativity is a measure of an atom's ability to attract electrons in a chemical bond, and it tends to decrease as one moves down a group in the periodic table. This means that Br- is less likely to attract electrons compared to Cl-, which can affect the types of chemical bonds it forms and the types of compounds it can form.In terms of physical properties, the larger size of Br- means that it has a larger polarizability compared to Cl-. Polarizability refers to the ability of an ion to distort its electron cloud in the presence of an electric field, and larger ions tend to have higher polarizability. This can affect the ability of the ions to form polar or non-polar interactions with other ions or molecules, as well as their ability to conduct electricity in a solution.In summary, the ionic radii of Cl- and Br- play an important role in determining their chemical and physical properties. The differences intheir ionic radii can affect their reactivity, solubility, and ability to form different types of chemical bonds. Understanding the ionic radii of these ions is important for understanding their behavior in various chemical and biological systems.。

专业英语作文英汉互译

共价键在学习有机化学时，我们经常用到键长、键能、键角和键的极性。

成键原子的原子核之间的平均距离，称为键长。

因为共价键在分子中不是孤立的，而是受其它键的相互影响，因此相同的共价键的键长在不同的化合物中也稍有差异。

键能是形成共价键过程中体系释放出的能量，或共价键断裂过程中体系所吸收的能量。

键能反映了共价键的强度，通常键能越大则键越牢固。

两价以上的原子在与其它原子成键时，键和键之间的夹角称为键角。

键角反映了分子的空间结构，键角的大小与成键的中心原子有关，也随着分子结构不同而改变，因为分子中各原子或基团是相互影响的。

由两个相同原子形成的共价键，电子云对称地分布在两个成键原子之间，这种共价键没有极性，称为非极性共价键。

而不同的原子形成的共价键，由于成键原子电负性不同，其吸引电子的能力不同，使电负性较强的原子的一端电子云密度较大，具有部分负电荷，而另一端则电子云密度较小，具有部分正电荷，这种键具有极性，称为极性共价键。

有机化学反应是旧键的断裂和新键的生成。

根据共价键的断裂方式的不同，可以把反应分为均裂和异裂。

均裂是成键的一对电子平均分给两个成键原子或基团。

均裂一般在光和热的作用下发生。

异裂是成键的一对电子完全成为成键原子中的一个原子或基团所占有，形成正负离子。

酸、碱或极性溶剂有利于共价键的异裂。

当成键两原子之一是碳原子时，异裂既可生成碳正离子，也可生成碳负离子。

自由基、碳正离子、碳负离子都是在反应过程中暂时生成的活性中间体。

根据活性中间体的不同，将反应分为自由基反应和离子基反应。

通过共价键均裂生成的自由基活性中间体而进行的反应，属于自由基反应。

通过共价键异裂生成碳正离子、碳负离子活性中间体而进行的反应，属于离子型反应。

Covalent BondWe often use bond length, bond energy, bond angle and bond polarity when study organic chemistry. The average distance between the nucleus of the atoms which will form the bond is bond length. The covalent bonds are rather related than isolated, consequently, the length of the same covalent bonds are tightly different. Bond energy is the energy which the system releases when covalent bonds form or when the energy which the system absorbs when covalent bonds fracture. Bond energy reflects the strength of the covalent bonds. Generally speaking, the larger the bond energy is, the stronger the covalent bonds are. When the atoms with valency bigger than two form bonds with other atoms, the angle between the bonds is called as bond angle. Bond angle reflects the spacestructure of the molecules. Bond angle is related to the central atom which will form the bond, and differs with the difference of molecule spacestructure. This attributes to the mutual influence of the atoms or the radicals of the molecules. When the same atoms form covalent, the electron cloud distributes meanly between the atoms. Covalent bonds of this kind have no polarity, calling nonpolar covalent bonds. Whendifferent atoms form covalent bonds, due to the difference of the electronegativity of the atoms, the ability to attract electrons is different , subsequently, making the electron cloud density of the atom with higher electronegativity larger, while, the other side smaller. This is polar covalent bond.The reaction of organic chemistry is the fracture of old bonds and the formation of new bonds. According to the ways of fracture, we can sort the reactions as homolytic reactions heterolytic reactions. Generally speaking, homolytic reactions occurs when the pair of electrons is meanly divided to the two atoms or groups. While, on the other hand, heterolytic reaction is definitely a pair of electrons owned by one atom or group, and what is more, forming anionic and cationic. Acid or base or polar solvent can contribute to the heterolysis of covalent bond. When one of the two atoms is carbon, heterolysis can form either carbocation or carbanion.Free radical, carbocation or carbanion are all active intermediates formed temporarily. According to the difference of active intermediates, we can classify the reactions as free radical reactions and ion radical reactions. The reactions which happen when covalent bonds homolysis to free radical active intermediates are free radical reactions. While, ion radical reactions occur when covalent bonds heterolysis to carbocation or carbanion.。

等离子体物理基础期末考试(含答案)

解：1、1/2302()8.310()e iD e i T T mm T T neελ-==⨯+， 2、氩原子量为40，221/21/200()8.0,()29pe pi e ine ne GHz MHz m m ωωεε====，3、14,0.19e i e ieB eB GHz MHz m m Ω==Ω== 4、设粒子运动与磁场垂直24.210, 1.3e e i i ce ci m v m v r mm r mm qB qB -===⨯===二、一个长度为2L 的柱对称磁镜约束装置，沿轴线磁场分布为220()(1/)B z B z L =+，并满足空间缓变条件。

求：（1）带电粒子能被约束住需满足的条件。

（2）估计逃逸粒子占全部粒子的比例。

解：1、由B(z)分布，可以求出02m B B =，由磁矩守恒得22001122m mmv mv B B ⊥⊥=，即0m v ⊥⊥= （1）当粒子能被约束时，由粒子能量守恒有0m v v ⊥≥，因此带电粒子能被约束住的条件是在磁镜中央，粒子速度满足002v v ⊥≥2、逃逸粒子百分比201sin 129.3%2P d d πθϕθθπ===⎰⎰ （2）三、在高频电场0cos E E t ω=中，仅考虑电子与中性粒子的弹性碰撞，并且碰撞频率/t t ea ea v νλ=正比于速度。

求电子的速度分布函数，电子平均动能，并说明当t ea ων>>时，电子遵守麦克斯韦尔分布。

解：课件6.6节。

亲电加成与消除反应 Polar Addition and Elimination Reactions

1
• The discussion of elimination reactions considers the classical E2, E1, and E1cb eliminations that involve removal of a hydrogen and a leaving group; • We focus on the kinetic and stereochemical characteristics of elimination reactions as key indicators of the reaction mechanism .
General observation (Markovnikov’s rule): the nucleophilic halide ion becomes attached to the more-substituted carbon atom.
11
The basis for this regioselectivity lies in the relative ability of the carbon atoms to accept positive charge.
Kinetics:
13
(1) complex formed by alkene and HCl
(2)
The TS involves proton transfer to the alkene from one HCl molecule and capture of the Cl- from the second: AdE3
Mechanism C is an important general mechanism that involves bonding of E+ to both carbons of the alkene and depends on the ability of the electrophile to function as a 9 bridging group.

电子信息类专业英语(西电第二版)Unit 4 Microel

Unit 4 Microelectronics
Integrated circuits are small, light, rugged, and reliable. They require less power and lower voltages than equivalent macroscopic circuits; consequently they operate at lower temperatures, and individual components may be close together without exceeding the operating temperature limit. Relatively little stray capacitance and short time delays are produced because of the short interconnections between the individual components in IC. Maintenance is simplified because if a component of the IC fails the complete IC is usually replaced. Mass production techniques of plane technology have reduced the cost of many IC so that they are almost as inexpensive as a single transistor. Eventually most conventional circuits will be replaced by IC.
［2］ The reduction in power dissipation is particularly important where a complex circuit is to be concentrated into a small space. The problem of extracting the heat generated in the circuit may then be a difficult one.

二价铜离子和一价铜离子颜色

二价铜离子和一价铜离子颜色英文版The Colors of Cupric Ions and Cuprous IonsIn the realm of chemistry, ions play a crucial role in determining the properties and characteristics of various compounds. Among these ions, copper ions are particularly fascinating due to their distinct colors. Specifically, cupric ions (Cu2+) and cuprous ions (Cu+) exhibit unique colors that can serve as valuable indicators in various chemical reactions and applications.Cupric ions, with a charge of +2, typically exhibit a blue color in aqueous solutions. This characteristic blue hue is due to the electron configuration of the cupric ion, which allows for the absorption of specific wavelengths of light, resulting in the visible blue color. The blue color of cupric ions is often utilized in analytical chemistry to detect the presence of copper or other compounds containing copper.On the other hand, cuprous ions, with a charge of +1, typically appear colorless or have a pale color in aqueous solutions. This is because the electron configuration of the cuprous ion does not absorb visible light in the same way as cupric ions, resulting in a lack of visible color. However, in some specific environments, cuprous ions can exhibit a reddish-brown color, depending on the ligands present and the conditions of the solution.The difference in color between cupric and cuprous ions can be attributed to their different electron configurations and the subsequent absorption of light. This color difference provides a valuable tool for scientists and researchers in various fields, allowing them to identify and monitor chemical reactions and compounds containing copper.中文版二价铜离子和一价铜离子的颜色在化学领域，离子在决定各种化合物的性质和特征方面起着至关重要的作用。

离子半径表英文

The ionic radius table is a valuable tool for chemists and students of chemistry, providing a quick reference to the sizes of ions in chemical compounds. The table lists the radii of various ions, arranged by their charge and element. It is important to note that ionic radii are not constant and can vary depending on the chemical environment in which the ion is found.The ionic radius is defined as the distance from the center of the nucleus to the outermost electron shell of an ion. For positively charged ions (cations), the ionic radius is generally smaller than the atomic radius of the corresponding neutral atom, as the loss of one or more electrons reduces the electron-electron repulsion and results in a tighter nuclear charge pull. Conversely, for negatively charged ions (anions), the ionic radius is generally larger than the atomic radius of the corresponding neutral atom, as the gain of one or more electrons increases the electron-electron repulsion and results in a larger electron cloud.The ionic radius table typically includes ions of the most common elements, as well as some more obscure ones. The table is organized in columns, with each column representing a different charge. The radii are listed in rows, with each row representing a different element.It is important to remember that the ionic radii listed in the table are average values and can vary depending on the specific chemical compound and conditions. For example, the ionic radius of sodium ion (Na+) is slightly smaller than the ionic radius of potassium ion (K+) in an aqueous solution, due to the differences in their electronic configurations and resulting charge densities.。

翻译原文

Comparison of Microstructure and Mechanical Propertiesof AZ91D Alloy Formed by Rheomoldingand High-Pressure Die Casting()The microstructure and mechanical properties of AZ91D alloy thin-wall parts produced by the 组织 AZ91D镁合金薄壁零件的机械性能产生rheomolding(RM) process were investigated and compared with the same alloy formed by conventional研究传统的high pressure die casting (HPDC). The results indicate that the RM process is able to get such AZ91D 高压压铸parts in which a1-Mg with average size of 27.36 l m are spherical and uniformly distributed in the球形均匀分布matrix, and the matrix is a mixture of numerous fine a2-Mg and intermetallic b-Mg17Al12. High mechanical 矩阵机械properties including ultimate tensile strength (UTS) of 270 MPa, yield strength (YS) of 169 MPa, 极限抗拉强度屈服强度elongation of 7.1%,and Vickers hardness of 102 are obtained in parts formed by RM due to the fine维氏硬度and uniform microstructure and less porosities. Compared with HPDC, the UTS, YS, elongation, and 组织均匀，气孔少压铸hardness of RM AZ91D are increased by 14.4, 9.7, 86.8, and 21.4%, respectively. The solidified grains凝固晶粒in RM AZ91D alloy show a smaller aluminum gradient than that in HPDC. This indicates that the较小铝梯度solidification of the RM AZ91D is closer to equilibrium..1. IntroductionMg-alloys, with a number of desirable properties including light weight, high specific strength理想性能比强度and specific stiffness,excellent damping property and well castability, are thus very 比刚度优良阻尼性能铸造性能attractive for the applications in 3C (computers, communications,and consumer electronics) andautomotive industries (Ref1-4). Over the past decades, with the rapid expansion of Mg-alloyapplications, large-scale thin-wall parts have been developed and implemented by taking full大型薄壁零件实施advantage of high-pressure die casting (HPDC) (Ref 5). However, HPDC partshave high-gas porosity levels, due primarily to the entrapment of air or gas in the melt during 高瓦斯孔隙度空气滞留the high-speed filling of turbulent molten metal into the cavity. The porosities can腔孔隙度severely degrade mechanical properties by acting as local stress concentrators. They also lead 降解浓缩机to problems during heat treatment or welding, where heating causes the expansion of gas in pores,热处理或焊接扩展and result in bubbling and dimensional changes (Ref 6). Also,repositories may have an adverse尺寸变化effect on the corrosion resistance of Mg-alloys (Ref 7).耐腐蚀性In order to solve these problems and meet demands of future applications, alternative castingprocess is developing. Semisolid metal (SSM) processing is a promising manufacturing半固态金属制造route that is capable of producing castings with a high level of quality. SSM processing involves 路线casting a semisolid slurry that exhibits non-turbulent or thixotropic flow behavior (Ref 8-10).铸造半固态浆料展品非湍流触变流动行为Semisolid cast alloys offer several advantages over their HPDC counterparts. For example, the 半固态铸造fraction of pores is lower owing to the laminar mold-filling process that results in less孔隙分数层流充型过程entrapped air (Ref 11, 12). SSM techniques are divided into two categories: thixo (thixomolding 截留空气类别触变(TM) and thixocasting (TC)) and rheo (rheomolding (RM) and rheocasting (RC)) processes.触变铸造流变流变铸造However, TC and RC are difficult to form thin-wall parts for the poor controllability of the melt temperature in chamber.Presently, the only commercially available SSM technology forthin-wall Mg-alloy parts is TM. Though TM has made a great progress and produced the parts withbetter strength and ductility, there still exist many shortcomings, such as poor wear resistance耐磨性差and short service life of the screw and the cylinder liner which are key components of thethixomolder (Ref 13).Moreover, using Mg-alloy particles as raw materials directly results in原材料the increase of production cost (Ref 13, 14).生产成本2. Experiment Procedures2.1 MaterialsCommercial AZ91D alloy was used in this investigation, for which the reported solidus and liquidus temperatures are 468 and 598 C, respectively. The chemical composition of theAZ91D alloy is 9.45% Al, 0.66% Zn, 0.20% Mn, 0.036% Si,0.005% Cu, 0.001% Ni, and Mg balance (by weight).2.2 The RM ProcessThe RM process is an innovative one-step SSM processing technique which, through the use创新一步半固态加工技术of LSP technology, can manufacture near-net shape parts with high integrity directly from liquid制造近净成形件完整性液体alloy without turbulence or gas entrapment.Figure 1 shows the schematic of the NISSEI FMg220-16HM 湍流或气体滞留示意图rheomolder which is composed of melting barrel, blunt gas injection pipe, storage tank, nozzle, injection system, etc.The melting barrel is suitable to accommodate rod-shaped materials with the size of U 609300 熔化筒容纳棒状材料mm, which are melted by heating components. The temperatures of storage tank and融化加热元件储存罐material temperature control barrel are considered as the melt temperature and pouringtemperature, respectively. The semisolid slurry is prepared in injection cylinder, which mainly半固态浆料喷油缸consists of the nozzle, runner, and material measurement room.The injection system is used to 喷嘴，流道和材料测量室注入系统inject the slurry into the mold cavity with high pressure and speed, and the forming parts are 浆phone covers (110960 mm) with the thickness of 0.8 mm.In the RM process, specific parameters were as follows: the melt temperature of 670 C,具体参数pouring temperature of 630 and 610 C, cylinder temperature of 570 C, injection pressure注射压力Of 35 MPa, injection velocity of 1.8 m/s, and mold temperature of 250 C. For the purpose ofcomparison, similar AZ91D phone covers (120955 mm) with a section thickness of 0.8 mm weredie casting on a 400-ton cold chamber HPDC machine. During HPDC, pouring temperature of 630 压铸400吨冷室压铸机。

POPs对生物体致病机理研究

ＰＯＰｓ对生物体致病机理研究　最近十几年来，由于与POPs有关的环境污染事件层出不穷，POPs会对生物体的神经系统、内分泌系统、免疫系统、生殖和发育产生严重的影响，并且有一些POPs是一级致癌物[1]。

2001年《关于持久性有机污染物的斯德哥尔摩公约》的签署，正式启动了向有机污染物宣战的进程。

其中，POPs对生物体致病机理是目前研究的重点和焦点之一，这方面的研究为制定更加有效的POPs控制措施，更好地保护地球上的生物提供确凿的科学依据。

１直接进入细胞　这种观点认为ＰＯＰｓ可能直接进入细胞内，作用于细胞核内的核酸或酶系统，引发遗传变异。

通过影响肝脏微粒体代谢酶细胞色素P450酶系的活性，导致机体甾体激素水平的改变和肿瘤发病率的升高[2,3]。

虽然其发生的机率很小，但是不排除其可能性。

基因转录激活[20]。

PCBs组成复杂，毒作用广泛，加上所用试验方法的不同，PCBs表现的类雌激素活性差异很大，对其作用机理的认识也刚刚开始，但是这一领域的研究近年来已经取得了很大的进展。

TCDD诱导细胞色素P450酶系的产生，使雌激素代谢加快而降低靶器官内雌激素浓度是可能的机理之一[21]。

当前研究发现，一些有机氯类物质能够干扰体内的雌激素水平，影响雌二醇的代谢，因而被称为乳腺癌的作用因子。

但是作用机制上，目前的研究结果尚不一致，因此，有必要对二者的因果关系作进一步的确切研究。

３作用于细胞信号传导通路　细胞内胞液中存在着一种配体依赖性转录因子——芳香烃受体，它在体内经历一个转变或激活过程，与芳香烃受体核转运（Amt）蛋白相互作用形成同型二聚化合物并移位至细胞核[22,23,24]。

　这种同型二聚化合物多某些特殊的DNA具有高度的亲和力，首先与之形成复合物，并诱发细胞内的信号传导，引起相关基因的如细胞色素P-450的表达和蛋白质的合成。

当他们作用于细胞的染色体，使染色体的数目或结构发生变化，从而改变携带遗传信息的某些基因，使一些组织、细胞的生长失控，产生肿瘤；一些可以与DNA共价键合，造成DNA６协同作用　研究表明，环境中存在的POPs中，有些单个对生物的影响很小，但是如果两种或是多种同时存在，则可能会出现惊人的相加作用，甚至可以达到单独作用的1000倍以上[31]。

XPS 课件

纳米材料的现代表征技术-课件电子能谱石建英中山大学化学与化学工程学院电子能谱分类X射线光电子能谱(简称XPS)(X-Ray Photoelectron Spectrometer)紫外光电子能谱(简称UPS) (Ultraviolet Photoelectron Spectrometer)俄歇电子能谱(简称AES)(Auger Electron Spectrometer)对固体样品，必须考虑晶体势场和表面势场对光电子的束缚作用，通常选取费米(Fermi)能级为的参考点。

b E 0k时固体能带中充满电子的最高能级对孤立原子或分子，就是把电子从所在轨道移到真空需的能量，是以真空能级为能量零点的。

b E φ++=b k E E hv 功函数φ++=b k E E hv 功函数为防止样品上正电荷积累，固体样品必须保持和谱仪的良好电接触，两者费米能级一致。

实际测到的电子动能为：spb s sp k k E hv E E φφφ−−=−−=)('spkb E hv E φ−−='仪器功函数特征：XPS采用能量为的射线源，能激发内层电子。

各种元素内层电子的结合能是有特征性的，因此可以用来鉴别化学元素。

eV 1500~1000UPS采用或作激发源。

与X 射线相比能量较低，只能使原子的价电子电离，用于研究价电子和能带结构的特征。

I(21.2eV) He II(40.8eV) He AES大都用电子作激发源，因为电子激发得到的俄歇电子谱强度较大。

光电子或俄歇电子，在逸出的路径上自由程很短，实际能探测的信息深度只有表面几个至十几个原子层，光电子能谱通常用来作为表面分析的方法。

X-ray Photoelectron Spectroscopy (XPS)XPS BackgroundXPS technique is based on Einstein’s idea about the photoelectric effect, developed around 1905\The concept of photons was used to describe the ejection of electrons from a surface when photons were impinged upon itDuring the mid 1960’s Dr. Siegbahn and his research group developed the XPS technique.\In 1981, Dr. Siegbahn was awarded the Nobel Prize in Physics for the development of the XPS techniqueIntroduction•X-ray photoelectron spectroscopy works by irradiating a sample material with monoenergetic soft x-rays causing electrons to be ejected.•Identification of the elements in the sample can be made directly from the kinetic energies of these ejected photoelectrons.•The relative concentrations of elements can be determined from the photoelectron intensities.Introduction (XPS)---Analysis capabilities•Elements detected from Li to U.•None destructive (some damage to x-ray beam sensitive materials)•Quantitative.•Chemical state analysis (some exceptions)•Surface sensitivity from 5 to 75 angstroms.•Conducting and insulating materials.•Detection limits that range form 0.01 to 0.5 atom percent.•Spatial resolution for surface mapping from >10 mm •Depth profiling capabilities.Photoemission of ElectronsConduction BandValence BandL2,L3L1K Fermi LevelFree Electron Level (vacuum)Incident X -ray Ejected Photoelectron1s 2s2p¾XPS spectral lines are identified by the shell from which the electron was ejected (1s, 2s, 2p, etc.).¾The ejected photoelectron has kinetic energy:¾KE= hv –BE -φ¾Following this process, the atom willrelease energy by the emission of aphoton or Auger Electron.XPS Energy Scale -Binding energyBE = hv-KE -ΦspecWhere: BE= Electron Binding EnergyKE= Electron Kinetic EnergyΦ= Spectrometer Work FunctionspecPhotoelectron line energies: Not Dependent on photon energy.X-RaysIrradiate the sample surface, hitting the core electrons (e-) of the atoms.The X-Rays penetrate the sample to a depth on the order of a micrometer.Useful e-signal is obtained only from a depth of around 10 to 100 Åon the surface.The X-Ray source produces photons with certain energies: \MgKαphoton with an energy of 1253.6 eV\AlKαphoton with an energy of 1486.6 eVNormally, the sample will be radiated with photons of a single energy (MgKαor AlKα). This is known as a monoenergetic X-Ray beam.Why the Core Electrons?An electron near the Fermi level is far from the nucleus, moving in different directions all over the place, and will not carry information about any single atom.\Fermi level is the highest energy level occupied by an electron in a neutral solid at absolute 0 temperature.\Electron binding energy (BE) is calculated with respect to the Fermi level. The core e -s are local close to the nucleus and have binding energies characteristic of their particular element.The core e -s have a higher probability of matching the energies of AlK αand MgK α.Core e -Valence e -Atom电离截面σ: 光电离过程发生的几率•由于光电子发射必须由原子的反冲来支持，所以同一原子中轨道半径愈小的壳层σ愈大。

外文翻译--正电原子在电离过程中碰撞的理论

英文原文Theory of ionization processes in positron–atom collisions AbstractWe review past and present theoretical developments in the description of ionization processes in positron–atom collisions. Starting from an analysis that incorporates all the interactions in the final state on an equal footing and keeps an exact account of the few-body kinematics, we perform a critical comparison of different approximations, and how they affect the evaluation of the ionization cross section. Finally, we describe the appearance of fingerprints of capture to the continuum, saddle-point and other kinematical mechanisms.Keywords: Ionization; Collision dynamics; Scattering; Electron spectra; Antimatter; Positron impact; Saddle-point electrons; Wannier; CDWPACS classification codes: 34.10.+x; 34.50.Fa1. IntroductionThe simple ionization collision of a hydrogenic atom by the impact of a structureless particle, the “three-body problem”, is one of the oldest unsolved problems in physics. The two-body problem was analyzed by Johannes Kepler in 1609 and solved by Isaac Newton in 1687. The three-body problem, on the other hand, is much more complicated and cannot be solved analytically, except in some particular cases. In 1765, for instance, Leonhard Euler discovered a “collinear” solution in which three masses start in a line and remain lined-up. Some years later, Lagrange discovered the existence of five equilibrium points, known as the Lagrange points. Even the most recent quests for solutions of the three-body scattering problem use similar mathematical tools and follow similar paths than those travelled by astronomers and mathematicians in the past three centuries. For instance, in the center-of-mass reference system, we describe the three-body problem by any of the three possible sets of the spatial coordinates already introduced by Jacobi in 1836. All these pairs are related by lineal point canonical transformations, as described in [1]. In momentum space, the system is described by the associated pairs (k T,K T), (k P,K P) and (k N,K N). Switching to the Laboratory reference frame, the final momenta of the electron of mass m, the (recoil) target fragment of mass M T and the projectile of mass M P can be written in terms of the Jacobi impulses K j by means of Galilean transformations [1]For decades, the theoretical description of ionization processes has assumed simplifications of the three-body kinematics in the final state, based on the fact that• in an ion–atom collision, one particle (the electron) is much lighter than the other two,• in an electron–atom or positron–atom collision, one particle (the target nucleus) is much heavier than the other two.For instance, based on what is known as Wick’s argument, the overwhelming majority of the theoretical descriptions of ion–atom ionization collisions uses an impact-parameter approximation, where the projectile follows an undisturbed straight line trajectory throughout the collision process, and the target nucleus remains at rest [2]. It is clear that to assume that the projectile follows a straight line trajectory makes no sense in the theoretical description of electron or positron–atom collisions. However, it is usually assumed that the target nucleus remains motionless.These simplifications of the problem were introduced in the eighteenth century. The unsolvable three-body problem was simplified, to the so-called restricted three-body problem, where one particle is assumed to have a mass small enough not to influence the motion of the other two particles. Though introduced as a means to provide approximate solutions to systems such as Sun–planet–comet within a Classical Mechanics framework, it has been widely used in atomic physics in the so-called impact-parameter approximation to ion–atom ionization collisions. Another simplification of the three-body problem widely employed in the nineteenth century assumes that one of the particles is much more massive than the other two and remains in the center of mass unperturbed by the other two. This approximation has been widely used in electron–atom or positron–atom ionization collisions.2. The multiple differential cross sectionA kinematically complete description of a three-body continuum final-state in any atomic collision would require, in principle, the knowledge of nine variables, such as the components of the momenta associated to each of the three particles in the final state. However, the condition of momentum and energy conservation reduces this number to five. Furthermore, whenever the initial targets are not prepared in any preferential direction, the multiple differential cross section has to be symmetric by a rotation of the three-body system around the initial direction of motion of the projectile. Thus, leaving aside the internal structure of the three fragments in the final state, only four out of nine variables are necessary to completely describe the scattering process. Therefore, a complete characterization of the ionization process may be obtained with a quadruple differential cross section:There are many possible sets of four variables to use. For, instance, we can chose azimuthal angles of the electron and of one of the other two particles, the relative angle between the planes of motion, and the energy of one particle.Such a choice is arbitrary, but complete in the sense that any other set of variables can be related to this one. A similar choice of independent variables has been standard for the description of atomic ionization by electron impact, both theoretically and experimentally [3] and [4].A picture of the very general quadruple differential cross section is not feasible. Thus, it is usually necessary to reduce the number of variables in the cross section. This can be achieved by fixing one or two of them at certain particular values or conditions. For instance, we might arbitrarily restrict ourselves to describe a coplanar (i.e. = 0) or a collinear motion (i.e. = 0 and θ1 = θ2), so as to reduce the dependence of the problem to three or two independent variables, respectively. The other option is to integrate the quadruple differential cross section over one or more variables.The former has been widely used to study electron–atom collisions, while the latter has been the main tool to characterize ion–atom and positron–atom ionization collisions. Particularly important has been the use of single particle spectroscopy, where the momentum of one of the particles is measured.3. Single particle momentum distributionsIn ionization by positron impact it is feasible to study the momentum distribution of any of the involved fragments. As is shown in Fig. 1, the momentum distributions for the emitted electron and the positron present several structures. First, we can observe a threshold at high electron or positron velocities because there is a limit in the kinetic energy that any particle can absorb from the system. The second structure is a ridge set along a circle. It corresponds to a binary collision of the positron with the emitted electron, with the target nucleus playing practically no role. Finally, there is a cusp and an anticusp at zero velocity in the electron and positron momentum distributions, respectively. The first one corresponds to the excitation of the electron to a low-energy continuum state of the target. The second is a depletion due to the impossibility of capture of the positron by the target nucleus. These momentum distributions allow us to study the main characteristics of ionization collisions. However, we have to keep in mind that any experimentaltechnique that analyzes only one of the particles in the final-state can only provide a partial insight into the ionization processes. The quadruple differential cross sections might display collision properties that are washed out by integration in this kind of experiments.Fig. 1. Electron and positron momentum distributions for theionization of helium by impact of positrons with incident velocityv = 12 a.u.4. Theoretical modelThe main question that we want to address in this communication is if there are some important collision properties in positron–atom collisions, that are not observable in total, single or double differential ionization cross sections, and that therefore have not yet been discovered. In order to understand the origin of these structures, we compare the corresponding cross sections with those obtained inion–atom collisions. To fulfill this objective it is necessary to have a full quantum-mechanical treatment able to deal simultaneously with ionization collisions by impact of both heavy and light projectiles that is therefore equally applicable – for instance – to ion–atom or positron–atom collisions. A theory with this characteristics will allow us to study the changes of any given feature of multiple-differential cross-sections when the mass relations among the fragments vary. In particular, it would allow us to study the variation when changing between the two restricted kinematical situations.The second important point is to treat all the interactions in the final state on an equal footing. As we have just explained, in ion–atom collisions, the internuclear interaction plays practically no role in the momentum distribution of the emittedelectron and has therefore not been considered in the corresponding calculation. In this work, this kind of assumption has been avoided.The cross section of interest within this framework isThe transition matrix can be alternatively written in post or prior forms aswhere the perturbation potentials are defined by (H−E)Ψi = V iΨi and (H−E)Ψf = V fΨf.For the Born-type initial statewhich includes the free motion of the projectile and the initial bound state Φi of the target, and the perturbation potential V i is simply the sum of the positron–electron and positron–nucleus interactions. The transition matrix may then be decomposed into two termsdepending on whether the positron interacts first with the target nucleus or the electron.In order to be consistent with our full treatment of the kinematics, it is necessary to describe the final state by means of a wavefunction that considers all the interactions on the same footing. Thus, we resort to a correlated C3 wave function that includes distortions for the three active interactions. The final-channelperturbation potential for this choice of continuum wave function is [5](1) In the case of pure coulomb potentials, the distortions are given bywith νj = m j Z j/k j. This model was proposed by Garibotti and Miraglia [6]for ion–atom collisions, and by Brauner and Briggs six years later for positron–atom and electron–atom collisions [7]. However, in all these cases the kinematics of the problem was simplified, as discussed in the previous section, on the basis of the large asymmetry between the masses of the fragments involved. In addition, Garibotti and Miraglia neglected the matrix element of the interaction potential between the incoming projectile and the target ion, and made a peaking approximation to evaluate the transition matrix element. This further approximation was removed in a paper by Berakdar et al. (1992), although they kept the mass restrictions in their ion-impact ionization analysis.5. The electron capture to the continuum cuspLet us review some results in a collinear geometry. We choose as the two independent parameters the emitted electron momentum components, parallel and perpendicular to the initial direction of motion of the positron projectile. The energy of the projectile is 1 keV. In Fig. 2, we observe three different structures: two minima and a ridge.Fig. 2. QDCS for ionization of H2 by impact of 1 keV positrons foremission of electrons in the direction of the projectile deflection.The origin of the ridge is very well understood. It corresponds to the electron capture to the continuum (ECC) cusp discovered in ion–atom collisions three decades ago by Crooks and Rudd [8]. They measured the electron energy spectra in the forward direction and observed a cusp-shape peak at exactly the projectile’s velocity. The first theoretical explanation [9] showed that it diverges in the same way as 1/k. This cusp structure was the focus of a large amount of experimental and theoretical research.Since the ECC cusp is an extrapolation across the ionization limit of capture into highly excited bound states, this same effect has to be present in positron–atom collisions. In fact, the observation of such an effect associated with positronium formation, while predicted two decades ago by Brauner and Briggs, remained a controversial issue. The reason for this dispute was that, in contrast to the case of ions, the positron outgoing velocity is not similar to that of impact, but is largely spread in angle and magnitude. Thus there is no particular velocity where to look for the cusp. And this is certainly so. If we evaluate the double differential cross section, we see that the cusp is clearly visible in ion–atom collisions, but just a very mild and spread shoulder in positron–atom collisions. Thus, to observe this structure it is necessary to increase the dimension of the cross section. For instance by considering a zero degree cut of the quadruple differential cross section in collinear geometry.Kover and Laricchia measured in 1998 the dσ/d E e dΩk dΩK cross section in a collinear condition at zero degree, for the ionization of H2 molecules by 100 keV positron impact [10]. The structure is not so sharply defined as for impact observed for heavy ions because of the convolution that accounts for the experimentalwindow in the positron and electron detection. Since the target recoil plays no significant role in this experimental situation, the present general theory gives results similar to those obtained by Berakdar [11], and both closely follow the experimental values.The same kind of experiment was performed by Sarkadi and coworkers in Argon ionization by 75 keV proton impact. They measured the quadruple differential ionization cross section in a collinear geometry for ion–atom collisions for the first time, and found the ECC cusp as in positron impact at large angles. In this case, we have to keep a complete account of the kinematics in order to reproduce the experimental results [12].6. Thomas mechanismLet us now go back to the ionization of H2 by 1 keV positron impact. A structure at 45° can be observed, which was predicted and explained in 1993 by Brauner and Briggs as due to the interference of two equivalent double-collision mechanisms. Each of these processes consists of a positron–electron binary collision, followed by the deflection by 90° of one of the light particles by the heavy nucleus. This mechanism was proposed by Thomas [13] as the main responsible of electron capture by fast heavy ions. In this case, since the electron and positron masses are equal, these two processes interfere at 45°.If we lower the energy from 1000 eV to 100 eV, this structure at 45° disappears, a result that is consistent with the idea that the Thomas mechanism is a high energy effect. But there is another structure, at about 22.5°, that persists. We will consider this structure in the next section.7. Saddle-point mechanismThe origin of the structure at about 22.5° is certainly more difficult to identify. To our best knowledge, it has not been predicted before in positron–atom collisions, even though the mechanism responsible of its origin was already been proposed in ion–atom collisions almost two decades before. The idea was that an electron could emerge from an ion–atom collision by lying in the saddle-point of the projectile and the residual target-ion potentials. This mechanism is clearly related to one of the equilibrium points discovered by Lagrange in 1772, or to the mechanism proposed by Wannier for low-energy electron emission. In the case of ion–atom collisions, the search for theoretical and experimental evidence of this mechanism was overcast by vivid controversy [14], [15], [16], [17] and [18].In the case of positron–atom collisions, for the electrons to be trapped in the saddle of the positron and residual-ion potentials, the electron and the positron must first perform a binary collision so as to end up with the right velocities(2)where εi is the binding energy of the target in the initial state.Application of energy and momentum conservation principles shows that the positron is deviated in an angle(3) Finally, for the electron to emerge in the same direction as the positron, it must suffer a subsequent collision with the residual-nucleus in a Thomas-like process. In this second collision, the electron is deflected by 90°and the residual target ion recoils in a direction that forms an angle of about 135° with the electron and the positron. This mechanism is depicted in Fig. 4.Thus, to check that the proposal of a saddle-point is correct, we look at whether our calculations show structures that are consistent with this description of saddle-point electron production.The minimum observed in the QDCS of Fig. 3 and Fig. 4 are located at precisely those points where the previous conditions on the energy and angle of any of the three particles are met.Fig. 3. QDCS for H2 ionization by 100 eV positrons in the restrictedcollinear geometry.Fig. 4. Mechanism proposed to lead to the observed saddle-likestructure.We made another test on the validity of the saddle-point mechanism. Fig. 5 shows that the structure arises exclusively from the t P term. This result is consistent with the proposed mechanism, where the saddle-point structure arises from a first positron–electron collision. Afterwards, both positron and electron are scattered by the nucleus.Fig. 5. QDCS for ionization of H2 by impact of positrons at 100 eVand electron energy E e = 19 eV.8. ConclusionsSummarizing the results presented in this communication, we have investigated the ionization of molecular hydrogen by the impact of positrons. The obtained quadruple differential cross-sections for the electron and the positron emerging in the same direction show three dominant structures. One is the well-known electron capture to the continuum peak. Another one is the Thomas mechanism. Finally, there is a minimum that might be interpreted as due to the so-called “saddle-point” ionization mechanism.But the main conclusion is that the study of the fully differential cross section might be hindered by a great number of difficulties, but the reward is that many different structures can be observed that otherwise are missed in double, single differential or total cross sections.中文译文正电原子在电离过程中碰撞的理论摘要我们回顾过去和现在正子原子在电离过程中碰撞理论的发展。

医药行业专业英语词汇

医药行业专业英语词汇（非常有用）FDA和EDQM术语: CLINICAL?TRIAL：临床试验? ANIMAL?TRIAL：动物试验? ACCELERATED?APPROVAL：加速批准? STANDARD?DRUG：标准药物? INVESTIGATOR：研究人员；调研人员PREPARING?AND?SUBMITTING：起草和申报? SUBMISSION：申报；递交? BENIFIT （S）：受益? RISK（S）：受害? DRUG?PRODUCT：药物产品? DRUG?SUBSTANCE：原料药? ESTABLISHED?NAME：确定的名称? GENERIC?NAME：非专利名称? PROPRIETARY?NAME：专有名称；? INN（INTERNATIONAL?NONPROPRIETARY?NAME）：国际非专有名称? ADVERSE?EFFECT：副作用? ADVERSE?REACTION：不良反应? PROTOCOL：方案? ARCHIVAL?COPY：存档用副本? REVIEW?COPY：审查用副本? OFFICIAL?COMPENDIUM：法定药典（主要指USP、?NF）．? USP （THE?UNITED?STATES?PHARMACOPEIA）：美国药典NF（NATIONAL?FORMULARY）：（美国）国家处方集? OFFICIAL＝PHARMACOPEIAL=?COMPENDIAL：药典的；法定的；官方的? AGENCY：审理部门（指FDA）? IDENTITY：真伪；鉴别；特性? STRENGTH：规格；规格含量（每一剂量单位所含有效成分的量）? LABELED?AMOUNT：标示量? REGULATORY?SPECIFICATION：质量管理规格标准（NDA提供）? REGULATORY?METHODOLOGY：质量管理方法? REGULATORY?METHODS?VALIDATION：管理用分析方法的验证COS/CEP?欧洲药典符合性认证ICH（International?Conference?on?Harmonization?of?Technical?Requirements?for?Registration?of PharmaceuticalsforHumanUse)人用药物注册技术要求国际协调会议ICH文件分为质量、安全性、有效性和综合学科4类。

离子半径的英语

离子半径的英语Ion Radius in EnglishThe concept of ion radius is essential in understanding the structure and properties of ionic compounds. An ion is an atom or molecule that has an unequal number of protons and electrons, resulting in a net electrical charge. The radius of an ion is the distance from the center of the nucleus to the edge of the electron cloud surrounding it.In general, the size of an ion is influenced by two main factors: the number of electrons and the number of protons. Cations, which are positively charged ions, typically have a smaller radius than their neutral atom counterparts because the loss of electrons reduces electron-electron repulsion. Conversely, anions, which are negatively charged ions, usually have a larger radius due to the addition of electrons and increased electron-electron repulsion.The radius of an ion can also be affected by the charge it carries. Higher charges on ions lead to a greater pull on the electrons by the nucleus, which can result in a smaller radius for cations and a larger radius for anions. This is known as the ionic contraction and expansion effect.Furthermore, ions with the same number of electrons are compared based on the number of protons. Ions with fewer protons will have a larger radius because the less positivecharge in the nucleus exerts a weaker pull on the electron cloud.The study of ion radii is crucial in various scientific fields, including chemistry, materials science, and geochemistry, as it helps in predicting the reactivity of ions, their solubility in different solvents, and thestability of ionic compounds. Understanding ion radii is also important in the design of new materials with specific properties, such as superconductors and catalysts.。

电离杂质对载流子的散射

Lattice scattering has been discussed by SEITZ, BARDEEN and SHOCKLEY, DLJMKE, EHRENREICH and OVERHAUSER, and others. Scattering by neutral impurities was considered by ERGINSOY. we focus attention on scattering of charge carriers by ionized impurities.
Ionized impurity scattering
In quantum mechanics, ionized impurity scattering is the scattering of charge carriers by ionization in the lattice.
The most primitive models can be conceptually understood as a particle responding to unbalanced local charge that arises near a crystal impurity; similar to an electron encountering an electric field. This effect is the mechanism by which doping decreases mobility.
Only when a lattice contains perfectly regular spacing can the ion-lattice interaction (scattering) lead to almost transparent behavior of the lattice. Impurity atoms in a crystal have an effect similar to thermal vibrations where conductivity has a direct relationship between temperature.

SATII化学知识点,公式总汇

Basic Electric Charges:∙The discovery of the electron as the first subatomic particle is credited to J.J. Thomson∙Robert Millikan (Millikan Oil Drop Experiment): Measure thecharge on an electron using the apparatus.∙Ernest Rutherford (Rutherford’s Experiment): Perform a goldfoil experiment that had tremendous implications for atomicstructure. [Alpha Particles]Mass Number, Isotopes, and Atomic Weight∙Atomic number: the smallest particle of an element; number of protons in nucleus; identity of element ∙Protons and neutrons each have mass of roughly 1 atomic mass unit (amu).∙Electrons have practically no mass.∙Mass number = protons + neutrons∙Isotopes: Two atoms of the same element differ in the number of neutrons (mass number) in their nuclei.∙Average of the mass numbers (does not appear on the periodic table) is called the atomic weight.Sublevels and electron configuration:∙The configuration that corresponds to the lowest electronic energy is called the ground state. Any other configuration is an excited state.Example: the ground state configuration of the sodium atom is 1s22s22p63s, the first excited state is obtained by promoting a 3s electron to the 3p orbital, toobtain the 1s22s22p63p configuration.Periodic Table Properties:∙Acid-forming properties increase from left to right.∙The atomic radii of elements decrease from left toright across a period∙Metallic properties are greatest on the left side.∙First ionization energies increase from left to right across a period.∙Electronegativity increase from left to right across a period. (Highest F 4.0)Empirical Formula & molecular formula∙An empirical formula shows the ratio of atoms within a molecule.∙Molecular formula of hydrogen peroxide is H2O2.∙The empirical formula for hydrogen peroxide is HO.Quantum Theory∙Bohr model: the incorrect idea that electrons orbit the nucleus in true orbits∙Heisenberg principle: electrons are located in orbitals, not orbitsOne cannot know an electron’s position and momentum at the same time ∙De Broglie’s hypothesis: matter (including electrons) can be thought of as having properties of both a particle and a waveIntramolecular Force [Strong]∙Ionic Bonds: Electronegativity values of two kinds of atoms differ by 1.7 or more.∙Nonpolar Covalent Bonds: Electronegativity difference between two atoms is 0 or very small (not greater than 0.5)∙Polar Covalent Bonds: Electronegativity values of two kinds of atoms differ by 0.4 to 1.6.Intermolecular Forces [Weak]∙Dipole-Dipole Attraction: Found in polar-molecules, unsymmetrical distribution of electronic charges.∙London Dispersion Forces: Found in both polar and nonpolar molecules, the weakest of all the electrical forces.∙Hydrogen bonds: Attractive force between the lone pair of an electronegative atom and a hydrogen atom that is bonded to nitrogen, oxygen, or fluorine.∙Hydrogen bonds occur between, not within molecules.Resonance∙The contributing structures are not isomers. They differ only in the position of electrons.∙Each Lewis formula must have the same number of valence electrons (and thus the same total charge), and the same number of unpaired electrons, if any.VSPER TheoryTrigonal planar BFSquare planarantiprismaticCapped square antiprismatic∙ AX 1 (e.g., LiH): no hybridisation; trivially linear shape∙ AX 2 (e.g., BeCl 2): sp hybridisation; linear or digonal shape; bond angles are cos −1(−1) = 180° ∙ AX 3 (e.g., BCl 3): sp 2 hybridisation; trigonal planar shape; bond angles are cos −1(−1/2) = 120° ∙ AX 2E (e.g., GeF 2): bent / V shape, < 120°∙ AX 4 (e.g., CCl 4): sp 3 hybridisation; tetrahedral shape; bond angles are cos −1(−1/3) ≈ 109.5° ∙AX 3E (e.g.,NH 3): trigonal pyramidal, 107°Note: The existence of a lone pair of electrons distorts bond angles slightly due to increased s-orbital character in the lone pair and increased p-orbital character in the orbitals used to make the bond pairs. It is not due to increased electron repulsion which is a very common misconception. ∙ AX 5 (e.g., PCl 5): sp 3d hybridisation; trigonal bipyramidal shape∙AX 6 (e.g., SF 6): sp 3d 2 hybridisation; octahedral (or square bipyramidal) shapeSigma and Pi Bonds∙ Pi bonds are usually weaker than sigma bonds.∙ Sigma bonds are the strongest type of covalent chemical bonds.∙Sigma bonds in polyatomic compounds obtained by head-on overlapping of atomic shells.Pressure Basics:∙ Units of pressure: standard pressure = 760 torr = 760 mm (Hg) = 1 atm ∙Pressure is measured with: barometer, manometer (lab.)Gas Laws∙ Graham ’s Law of Effusion (Diffusion): √∙ Charles ’s Law:∙ Boyle ’s Law : ∙ Pressure Versus Temperature (Gay- Lussac ’s Law):∙ Combined Gas Law:∙Ideal Gas Law:→→→→→ →WATER:∙Heat of fusion: 80 cal/g or 3.34*10^2 J/g or 6.01 kg/mol∙Specific heat capacity: 1 cal/g/1℃ or 4.18 J/g/1℃∙Heat of vaporization: 540 cal/g or 40.79 KJ/mol∙Percentage concentration:∙Specific gravity: ratio of the mass of a substance to the mass of an equal volume of water∙Molarity:∙Molality:∙Dilution:∙ 1 Mole of particle Freezing Point -1.86, Boiling Point +0.51∙Only a temperature change, not a concentration change, can change the energy of molecular collisions.∙The only gaseous and aqueous species can have their concentration increased.Vapor Pressure∙The substance’s temperature.∙Its mole fraction when it’s in solution.Energy Basics:∙Kinetic energy is the energy contained in the movement of molecules. The greater the kinetic energy, the faster the movement and the higher the temperature of the molecules.∙Chemical bonds contain energy. Breaking bonds requires energy; forming bonds releases energy.∙Heat is the transfer of kinetic energy from one thing to another.∙ A calorimeter measures energy.∙Units of energy: 1 calorie = 4.184 joules∙Temperature: average kinetic energy; K = ℃ + 273Predicting Reactions∙Combination (Synthesis): If the heat of formation is a large number preceded by a minus sign, the combination is likely to occur spontaneously and the reaction is exothermic.∙Decomposition (Analysis): If the heat of formation to decompose since this same quantity of energy must be returned to the compound.∙Single Replacement: Based on a comparison of the heat of formation of the original compound and that of the compound to be formed.∙Double Replacement: An insoluble precipitate is formed, a nonionizing substance is formed, or a gaseous product is given off.∙Hydrolysis Reactions: The salt and water react to form an acid and a base.Entropy (S) & Enthalpy (H)∙ Higher Entropy + Lower Energy -> More Stability ∙ Lower Entropy + Higher Energy -> Less Stability∙ Exothermic reaction -> energy is released -> ∆H < 0 -> enthalpy decreases ∙ Endothermic reaction -> energy is absorbed -> ∆H < 0 -> enthalpy increases ∙ ∆H f = ∆H f (products) - ∆H f (reactants)∙ If ∆G < 0, then the reaction is spontaneous in the forward direction. ∙ If ∆G > 0, then the reaction is spontaneous in the reverse direction.Laws of Thermodynamics∙ The zeroth law of thermodynamics: states that if two systems are in thermal equilibrium with a third system, they are also in thermal equilibrium with each other.∙ The first law of thermodynamics: states the energy of an isolated system is constant.∙ The second law of thermodynamics: the principle of the increase of entropy and explains the phenomenon of irreversibility in nature.∙ The third law of thermodynamics: the entropy of a system approaches a const. value as the temperature approaches zero.Factors Affecting Reaction Rates∙ The nature of the reactants ∙ The surface area exposed ∙ The concentrations ∙ The temperature ∙The presence of a catalystCommon Ion Effect∙When a reaction has reached equilibrium and an outside source adds more of one of the ions that is already in solution, the result is to cause the reverse reaction to occur at a faster rate and reestablish the equilibrium.Acid-Base Theories∙The Arrhenius theory: A base as a substance that yields hydroxide ions in an aqueous solution. ∙ The Bronsted-Lowry Theory: A proton donors and bases as proton acceptors.∙ The Lewis Theory: An acid is an electron-pair acceptor; and a base is an electron-pair donor. ∙Conjugate acids and bases appear on the right side of the equation.Buffer Solutions∙ Mixing equal molar quantities of a weak acid such as HC 2H 3O 2 ∙Made up of a weak acid and its conjugate base.Amphoteric SubstancesGibbs Free Energy:∆G = ∆T - T∆S∙ Amphoteric substances donate protons in the presence of strong bases and accept protons in the presenceof strong acids.Important Industrial Methods∙ Haber Process: NH 4 ∙ Hall Process: Al ∙Dow Process: MgAlloys∙ Melting point: the melting point of an alloy is lower than that of its components ∙ Hardness: An alloy is usually harder than the metals that compose it.∙ Crystal Structure: If the alloy cools slowly, the crystalline particles tend to be larger. ∙ Brass: Copper + Zinc ∙ Bronze: Copper + Tin∙Steel: Carbon + Manganese + Sulfur + Phosphorus + Silicon + Nickel + Chromium∙ Alkane Series (C n H 2n+2): Meth-, Eth-, Prop-, But-, Pent- ∙ Alkene Series (C n H 2n ) ∙ Alkyne Series (C n H 2n-2)∙ Alcohols (Methanol and Ethanol): -OH ∙ Aldehydes: -COH∙ Organic Acids or Carboxylic Acids: -COOH ∙ Ketones: -R-O-C-R ∙ Ethers: R-O-R ∙ Amines: -NH 2 ∙ Esters: -COO∙ Methanol + [O]→ methanoic acid∙ Ethane →monochloro-ethane →ethanol-→ethanol →ethanoic acid ∙ Ethanoic acid+ ethanol → ethyl ethanoate ∙Alcohol + acid →esterRadioactive decayType of decay Problem with nucleus Conversion Emitted particle Nuclear change Alpha decay Nucleus is too heavy Two protons and two neutrons split off of the nucleus Alpha particle or helium nucleus Atomic number decreases by 2; mass number decreases by 4 Beta decay Too many neutrons, toofew protons An electron is pulled off of a neutron, which turns into a proton Beta particle or electron Atomic number increases by 1; mass number is unchanged Positron emissionToo many protons, too few neutrons A positron or positive electron is pulled off a proton, which turnsinto a neutron PositronAtomic number decreases by 1; mass number is unchanged Gamma decay Too much energyA nucleus releases energy in the form of high energy radiationGamma photonNucleus becomes more stable but is otherwise unchanged Electron Capturee-Atomic number decreases by 1; mass number is unchanged。

LiFePO_(4)改性电极同时测定抗坏血酸、多巴胺和尿酸

第49卷第7期2021年4月广州化工Guangzhou Chemical IndustryVol.49No.7Apr.2021LiFeP()4改性电极同时测定抗坏血酸、多巴胺和尿酸*梁亚鸣，袁红雁(四川大学化学工程学院，四川成都610065)摘要：将磷酸铁锂(LiFePO4>LFP)与石墨(G)混合后用于改性普通玻碳电极(GCE),制备出一种新型电化学传感器(LFP-G/GCE),利用锂离子的脱嵌加速电子转移，实现同时检测抗坏血酸(AA)、多巴胺(DA)和尿酸(UA)O通过循环伏安法(CV)和差分脉冲伏安法(DPV)研究了LFP-G/GCE对AA、DA和UA的电化学行为。

此外，LFP-G/GCE可用于检测人血清中的UA,计算出人血清中UA的初始浓度为375|xM o AA和DA的回收率也令人满意。

因此LFP材料的应用可以扩展到电化学传感领域。

关键词：磷酸铁锂；电化学传感器；抗坏血酸；多巴胺；尿酸中图分类号：TP212.2文献标志码：A文章编号：1001-9677(2021)07-0088-07LiFePO4Modified Electrode for Simultaneous Determination ofAscorbic Acid,Dopamineand Uric Acid*LIANG Ya-ming,YUAN Hong-yan(College of Chemical Engineering of Sichuan University,Sichuan Chengdu610065,China)Abstract:A new electrochemical sensor(LFP-G/GCE)was prepared by mixing lithium iron phosphate(LiFePO4, LFP)with graphite(G)to modify glassy carbon electrode(GCE),and utilizing intercalation and deintercalation of Li-ion of LFP accelerated the electron transfer,the LFP-G/GCE determination of ascorbic acid(AA),dopamine(DA)and uric acid(UA)simultaneously.The electrochemical behaviors of LFP-G/GCE toward AA,DA and UA were investigated by the methods of cyclic voltammetry(CV)and differential pulse voltammetry(DPV).Furthermore,LFP-G/GCE can be used to detect UA in human serum,the original concentration of UA in human serum was calculated as375|jl M.The recoveries of AA and DA in serum samples were also satisfactory.The application of the battery material LFP can be extended to the field of electrochemical sensing.Key words：lithium iron phosphate；electrochemical sensor；ascorbic acid；dopamine；uric acidLiFePO4(LFP)作为一种正极材料，具有低毒、低成本、循环能力强、安全性高等优势，自1997年报道以来被广泛研究并实现工业化生产⑴。

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1 MeV electrons Dose rate = 10-3 dpa/s
Evolution of Order in Ni4Mo under electron Irradiation
170 K
473 K
Disordering of LRO state
Persistence of 1½ 0 order (SRO) in initial SRO state
AV AV BV BV
Asymmetric energy barrier for vacancy-atom Interchange in ordered alloy
Order-parameter vs. temperature plots - equilibrium condition - steady state condition under irradiation
nth order transformation: n F / T n 0 ; n 1 F / T n 1 0
First Order
Second order
F
E
Cp Temperature
First & second order transitions: Landau Plots
Empty lattice
Atoms A & B
Chemical Ordering
Electric/ magnetic moments
Ferromagnetic Ferroelectric Ordering
Outline
•Ordering – chemical, magnetic, & electric • Evolution of Ordering • Competing superlattices in Ni4Mo alloy • Influence of radiation on order disorder • Order evolution
d dS tt kC AC BkC AC B
k

Z C VZ Z C V Z
CV CV
equilibrium
Under irradiation
S. Banerjee, K. Urban, Phys. Stat. Sol., 81, (1984) 145
No LRO state below 450 K No SRO State below 200 K
S Banerjee, K Urban, M. Wilkens Acta Met., 32 (1984) 299
Ordering & Disordering Jumps
0ex p EmU 2/kT
-- under electron irradiation -- under heavy ion irradiation Comparison of electron and ion irradiation results Conclusions
Ordering – Chemical, ferromagnetic, ferroelectric
-- under electron irradiation -- under heavy ion irradiation Comparison of electron and ion irradiation results Conclusions
Electron Irradiation Results
-- under electron irradiation -- under heavy ion irradiation Comparison of electron and ion irradiation results Conclusions
Evolution f order
Nucleation and Growth Continuous Ordering
Materials Science Division Bhabha Atomic Research Division
Mumbai 400085
* email:msramanapsara.barc.ernet.in
Outline
•Ordering – chemical, magnetic, & electric • Evolution of Ordering • Competing superlattices in Ni4Mo alloy • Influence of radiation on order disorder • Order evolution
-- under electron irradiation -- under heavy ion irradiation Comparison of electron and ion irradiation results Conclusions
Description of LRO and SRO structures
LRO state
C c [ p 1 2 lC o p /5 s C 2 o p /5 ] s4 p = 0,1,2,3 for <1 ½ 0> modulation
SRO state
C c p [1 2 ss{ i n (p 1 /2 )/2 }] p = 0,1,2,3, 4 for 1/5<1 ½ 0> modulation
A COMPARISON OF THE ELECTRON AND ION IRRADIATION EFFECTS ON THE STABILITY RANGE OF ORDERED STRUCTURES IN Ni4 Mo
M. SUNDARARAMAN* and S. BANERJEE Presented by G. K. DEY
-- under electron irradiation -- under heavy ion irradiation Comparison of electron and ion irradiation results Conclusions
Ordered States in Ni4 Mo
* Above 1140 K alloy is in SRO state * Below 1140 K alloy is in LRO state * By conventional solutionising and quenching treatment alloy can not be produced in the completely disordered state (CDO) * LRO and SRO are two different states
Evolution of Order in Ni4Mo under electron Irradiation
<1 ½ 0> & 1/5 <420> diffraction spots
Damage rate: 10—3 dpa/s
remain linked during evolutionary stages S Banerjee, K Urban, M. Wilkens
Order evolution could be either first or second order
Evolution of Ordering: Discrete Mode (Nucleation & Growth)
Nucleation
Disordered Matrix
Evolution of Ordering – Static Concentration Waves
[001] Projection
Structural description of <1 ½ 0> Ordering
Different from SRO intensifying to become LRO
SRO <1 ½ 0>
LRO 1/5 <420>
Isostructural microdomains
Concentration wave packets
Disordered matrix Multiple microdomains
Microdomains
Outline
•Ordering – chemical, magnetic, & electric • Evolution of Ordering • Competing superlattices in Ni4Mo alloy • Influence of radiation on order disorder • Order evolution
Single Variant <100> K vector – B2 Ordering
3 variants <100> K vector – L12 ordering
Continuous Ordering
Amplification of concentration wave with time
First & second order transitions: Thermodynamic viewpoint
waves & simultaneous amplification of LRO D: Initially as in region C, after <1 ½ 0> disappear,
D1a domains nucleate & grow E: Nucleation & growth of D1a F: Destruction of <1 ½ 0> G: <1 ½ 0> order decays at T > 550 K H: <1 ½ 0> grows I: Destruction of <1 ½ 0> & transition to LRO