Oxygen and NItrogen Contamination during Arc Welding
ISSUES IN FOOD SAFETY
ISSUES IN FOOD SAFETY
第2页
In recent years, with the rapid development of economic, people's living standards are continuously improving, more and more people are paying their attentions on food safety issues, which also have become a global public health issue. Otherwise, the global food supply chain has changed, which means that our food on the table can possibly come from any corner in the world. Therefore, there are no boundaries for food safety issues; people from all over the world are trying their best to solve it. Although the governments of entire world are taking a series effective measure to reduce and prevent the occurrence of food safety accidents, they happened frequently in each year in the world.
1.1 Food safety issues originate from the entire food supply chain第 4 页
Carrousel2000氧化沟系统设计说明书【范本模板】
目录摘要 (2)1 前言 (3)2 工程概述 (4)2。
1 项目简介 (4)2。
2设计依据及规范 (4)2.3设计原则 (4)2.4自然资料与城市概况 (5)2.5 设计水量及进出水水质 (6)2.6污水处理程度 (6)2.7污水处理厂厂址 (7)3污水处理厂工艺设计 (9)3。
1工艺设计原则 (9)3.2污水处理工艺比较 (9)3。
3 工艺流程的选择 (12)3。
4污泥处理工艺比较 (14)3.5污水处理厂工艺流程 (14)4污水处理构筑物的设计及计算 (16)4。
1中格栅 (16)4。
2污水提升泵房 (19)4.3细格栅 (20)4.4平流式沉砂池 (24)4.5卡鲁赛尔2000型氧化沟 (27)4.6二沉池的设计 (35)4。
7紫外线消毒 (41)4。
8计量设施 (42)5污泥处理处理构筑物的设计计算 (44)5。
1污泥浓缩池的设计 (44)5。
2污泥泵房 (47)5。
3污泥脱水机房 (48)6污水处理厂总体布置 (51)6.1污水处理厂平面布置 (51)6。
2污水处理厂高程布置 (52)7污水处理厂劳动定员 (1)7.1生产组织 (1)7。
2劳动定员 (1)7。
3人员培训 (1)8污水处理厂工程技术经济分析 (2)8。
1工程概算 (2)8。
2污水处理成本 (2)9环境保护、建筑防火和职业安全防护 (4)9.1环境保护 (4)9.2建筑防火 (5)9。
3职业安全防护 (5)10 结论 (5)总结与体会 (6)致谢 (7)摘要近年来，随着崇州市城区的不断发展，城市生活污水产生量急剧增加。
该市拟于崇州市崇阳镇徐渡村兴建崇州城市生活污水处理厂，污水厂总设计规模40000m3/d，一期工程为20000m3/d及40000m3/d的配套设施，采用卡鲁赛尔2000氧化沟工艺。
Carrousel2000氧化沟系统是在普通Carrousel氧化沟前增加了一个厌氧区和缺氧区（又称前反硝化区）而形成的一个具有良好除磷脱氮效果的污水处理工艺，它综合了A/O法和氧化沟法的优点，完成有机污染物去除、硝化反硝化脱氮和除磷。
二硼化钛陶瓷在不同温度下的氧化行为_英文_
二硼化钛陶瓷在不同温度下的氧化行为黄飞，傅正义，王为民，王皓，王玉成，张金咏，张清杰(武汉理工大学，复合材料新技术国家重点实验室，武汉 430070)摘要：采用静态氧化法对不同温度下TiB2陶瓷的氧化行为进行研究，利用X射线衍射仪、扫描电镜、X射线光电子能谱仪对氧化前后的样品进行表征。
结果表明：低温下TiB2陶瓷氧化动力学满足抛物线规律，并在表面形成液相B2O3，阻止氧化反应的进一步进行，冷却后B2O3以玻璃态覆盖在表面。
高温下TiB2氧化反应在4h前满足抛物线规律，表面形成一层TiO2多孔结构；氧化4h后，随着氧扩散距离的延长，扩散阻力加大，从而使氧化速率降低，氧化反应不再满足抛物线规律。
关键词：二硼化钛；氧化动力学；微观结构中图分类号：TF123；TB332 文献标识码：A 文章编号：0454–5648(2008)05–0584–04OXIDATION BEHA VIOR OF TITANIUM DIBORIDE CERAMIC AT DIFFERENT TEMPERATURES HUANG Fei，FU Zhengyi，W ANG W eimin，W ANG Hao，W ANG Yucheng，ZHANG Jinyong，ZHANG Qinjie(State key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University ofTechnology, Wuhan 430070, China)Abstract: The oxidation behavior of TiB2 ceramics at different temperatures was investigated using the static oxidation kinetic method. The samples before and after oxidation have been characterized by X-ray diffractometer, scanning electron microscope and X-ray photoelectron spectrometer. The results show that the oxidation kinetics appear the parabolic law at low temperature. A liquid B2O3 coating on the surface of TiB2 ceramic could prevent from further oxidation. After the ceramic samples were cooled, their sur-faces were covered with glassy B2O3. At high temperature, the oxidation reaction of TiB2 ceramics showed the parabolic law only before 4h. Porous rutile TiO2 formed on the surface. But the oxidation behavior with the parabolic law for the TiB2 ceramics was not observed after oxidation for 4h because of the long path of diffusion, strong diffusion resistance and low reaction rate.Key words: titanium diboride; oxidation kinetics; microstructureTitanium diboride with P6/mmm structure is a uniquely stable compound of the boron element and tita-nium element.[1] TiB2 based materials have received wide attention because of their high hardness and elastic modulus, good abrasion resistance and superior thermal and electrical conductivity.[2–3] Potential applications in-clude high temperature structural materials, cutting tools, armor, electrodes in metal smelting and wear parts. De-spite its useful properties, the application of monolithic TiB2 is limited by poor sinterability, exaggerated grain growth at high temperature and poor oxidation resistance above 800.℃[4–5]The starting temperature to oxidize TiB2 ceramics is about 400℃ and oxidation kinetics is controlled by outward diffusion of interstitial titanium ions and inner diffusion of oxygen ions.[5–6] But there are conflicting viewpoints about the detailed oxidation process, for ex-ample, about the oxidation products and oxidation mechanism. Koh et al.[7] investigated the oxidation be-havior of dense TiB2 specimens with 2.5% in mass (the same below) Si3N4 and found that TiB2 exhibited two distinct oxidation behaviors depending on the tempera-ture. At temperatures below 1000℃, the oxidation layer comprised two layers: an inner layer of crystalline TiO2 and an outer layer mainly composed of B2O3. When the oxidation temperatures were higher than 1000℃, the收稿日期：2007–09–23。
氮杂环戊烷氧基 英语
The term "氮杂环戊烷氧基" in Chinese refers to a nitrogen-containing cyclopentane oxygen group in English. Breaking down the term, we have "氮杂" which means nitrogen-containing, "环戊烷" which means cyclopentane, and "氧基"which means oxygen group.### **1. Chemical Structure and Characteristics:**The nitrogen-containing cyclopentane oxygen group refers to a molecular structure where a cyclopentane ring is bonded to a nitrogen atom with an oxygen functional group attached. The presence of nitrogen in the cyclopentane ring introduces heteroatoms into the structure, imparting unique chemical properties compared to simple hydrocarbons.### **2. Nomenclature:**In organic chemistry, the nomenclature of compounds is essential for accurately describing their structure. The IUPAC (International Union of Pure and Applied Chemistry) nomenclature is commonly used. For a compound like this, the IUPAC name would involve specifying the position of the nitrogen, the presence of the cyclopentane ring, and the oxygen group.### **3. Applications:**Understanding the structure and properties of nitrogen-containing cyclopentane oxygen groups is crucial in various fields, including medicinal chemistry, materials science, and organic synthesis. Compounds with such functional groups may exhibit unique biological activities or be used as building blocks in the synthesis of more complex molecules.### **4. Medicinal Chemistry:**In drug discovery, nitrogen-containing heterocycles are often found in pharmacologically active compounds. The presence of the cyclopentane ring and oxygen group in this context could influence the compound's bioavailability, binding affinity, or metabolic stability.### **5. Materials Science:**In materials science, the incorporation of nitrogen-containing groups can alter the physical and chemical properties of materials. Depending on the specific application, the presence of the cyclopentane ring and oxygen group may contribute to desirable characteristics such as enhanced solubility, reactivity, or stability.### **6. Organic Synthesis:**Chemists use nitrogen-containing cyclopentane oxygen groups as building blocks in organic synthesis. These functional groups can participate in various chemical reactions, allowing for the creation of diverse and complex molecular structures.### **7. Research and Development:**Ongoing research in the field of organic chemistry focuses on designing and synthesizing compounds with specific functionalities. Understanding the properties and reactivity of nitrogen-containing cyclopentane oxygen groups contributes to the development of new materials, drugs, or catalysts.### **8. Challenges and Considerations:**Despite the potential benefits of compounds with nitrogen-containing cyclopentane oxygen groups, there may be challenges in their synthesis or practical applications. These challenges could include the development of efficient synthetic routes, the optimization of reaction conditions, or considerations related to the compound's stability and toxicity.### **9. Future Perspectives:**As research in organic chemistry advances, the exploration of novel functional groups and their applications continues. The nitrogen-containing cyclopentane oxygen group represents a specific motif within this broader landscape. Future studies may uncover new reactions, properties, or applications for compounds containing this unique structural element.### **Conclusion:**The nitrogen-containing cyclopentane oxygen group is a chemically intriguing motif with potential applications in various scientific disciplines. Its presence in organic compounds can impart unique properties that make it valuable in fields ranging from medicinal chemistry to materials science. Ongoing research and exploration of the reactivity and characteristics of this functional group contribute to the advancement of organic chemistry and the development of innovative materials and compounds.。
氧弹燃烧-离子色谱法测定油基切削液中的卤素
氧弹燃烧-离子色谱法测定油基切削液中的卤素吴志刚曹璨(辽宁省分析科学研究院，沈阳110015)摘要：建立了氧弹燃烧-离子色谱法测定油基切削液中卤素的分析方法。
通过对氧弹燃烧装置条件优化，采 用胶囊称取〇.2g样品，充氧压力2.5 M Pa，吸收液20m L，静置吸收时间20min。
用离子色谱法测定吸收液中F-、C r、Br^的含量，结果表明，该方法定量检测限为5mg/kg〜9mg/kg,在0.02mg/L〜0_40mg/L线性范围良好，相关系数在〇• 9993〜0• 9996之间，精密度为3. 6%〜9.8%。
不同浓度加标回收率在93. 3%〜104. 0%之间，该方法 快速、准确、回收率高，重复性好，能够满足对切削液质量控制的需求。
关键词：切削液氧弹燃烧离子色谱卤素DOI：10. 3969/j.issn. 1001 —232x.2018. 04. 007Determination of halogens in oil based cutting fluid by oxygen bomb-ion chromatography. W u Zhigang' , C a o C a n iL ia o n in g A n a ly sis S c i e n c e A c a d e m e,S h e n y a n g,C h in a)Abstract：A n oxygen b o m b analytical method for determination of halogen in o i l based cutting fluid by ion chromatography was established.T h e oxygen b o m b combustion conditions were optimized and the results were as follows： 0.2g sample weighed using capsule was adopted.T h e oxygen pressure was2.5 M P a while the volume of the absorption liquid was20m L with a static absorption time of20min.T h e concentrations of F_ ,Cl- and Br_ in the absorption liquid were determined by ion chromatography.T h e results showed that the detection limits of the method were within 5m g/kg-9 m g/kg.T h e linear range was 0.02m g/L—0.40m g/L with favorable linear relationship,and the correlative coefficients were within 0. 9993 —0. 9996. The relative standard deivations were in the range of3.6%—9.8%.The recoveries with different concentrations were between 93. 3%and 104. 0%.I t was a rapid and accurate method with high recovery and good repeatability,which can satisfy the quality control requirement of cutting fluid.Key words：Cutting fluid；Oxygen b o m b combustion；Ion chromatography；Halogen随着装备制造业在我国的迅速发展，金属制品 的长期耐腐性能需求不断提高。
《高级病理生理学》讲座Ⅰ氧化应激-自由基活性氧与疾病Ⅱ缺血-再灌注损伤 与预适应
• H2O2(hydrogen peroxide)生成
®岐化反应
° 非酶促氧化：
O2·- +O2·- +2H+ SOD H2O2+O2 ·-
®自氧化/加单氧；
• 1O2 (singlet oxygen)生成
®线粒体受损：
®三重态氧→ 1O2(激发态分子氧)
O2 +‧UQ- →‧O2‾ + UQ； FADH+O2→NAD+ + ‧O2‾
￭ 线粒体DNA易受损： •原因：代谢转换率高, 自由基来源多；无组 蛋白保护；缺乏损伤 修复机制；缺乏复制 酶无校读功能致错率 高,等。 •方式：碱基缺失多见。
机体抗氧化防御系统
(Antioxidant Defense System in Body)
￭抗氧化酶和蛋白系统 •Cu+2,Zn+2/Mn+3 _SOD：抗O·-2 •Fe+3-CAT(catalase) ：抗H2O2 •Se - GSH/Px：清除LOOH
图 ROS 和亲电剂诱发启动的保护(抗氧化/适应)和 积累损伤(氧化应激)效应
(Initial & Accumulatory Effects of Chemically induced Superoxide & Electrophiles)
抗氧化剂 Vit,等
活性氧
氧化剂 芳香化合物 UV 重金属,等
《高级病理生理学》讲座
Ⅰ.氧化应激-自由基、活性氧 与疾病
Ⅱ.缺血-再灌注损伤 与预适应
(Part 1.Oxidative Stress-Free Redical ,ROS & Disease
氮气物理吸附英文
氮气物理吸附英文Nitrogen Gas Physical AdsorptionNitrogen gas, with its chemical formula N2, is a colorless, odorless, and inert gas that makes up approximately 78% of the Earth's atmosphere. This ubiquitous gas has a wide range of applications, from industrial processes to medical and scientific research. One of the fundamental properties of nitrogen gas is its ability to undergo physical adsorption, a process that has significant implications in various fields.Physical adsorption, also known as physisorption, is a phenomenon where molecules or atoms of a substance (the adsorbate) accumulate on the surface of another substance (the adsorbent) without forming chemical bonds. This process is driven by the attractive forces between the adsorbate and the adsorbent, such as van der Waals forces and electrostatic interactions. In the case of nitrogen gas, the physical adsorption of N2 molecules onto various adsorbents has been extensively studied and has found numerous applications.One of the primary applications of nitrogen gas physical adsorption is in the field of gas separation and purification. Nitrogen gas can beselectively adsorbed onto specific adsorbents, such as activated carbon, zeolites, or metal-organic frameworks (MOFs), while other gases, such as oxygen or carbon dioxide, are not adsorbed as strongly. This selective adsorption allows for the efficient separation and purification of nitrogen gas from air or other gas mixtures. This process is particularly useful in industrial settings, where high-purity nitrogen gas is required for various applications, such as in the electronics industry, food packaging, or the production of chemicals.Another important application of nitrogen gas physical adsorption is in the area of gas storage and transportation. Nitrogen gas can be adsorbed onto porous adsorbents, such as activated carbon or metal-organic frameworks, to create high-density storage systems. These adsorbent-based storage systems can store a significantly larger amount of nitrogen gas compared to traditional compressed gas cylinders, making them more efficient and cost-effective for transportation and storage. This technology is particularly relevant in applications where large volumes of nitrogen gas are required, such as in the industrial or medical sectors.The physical adsorption of nitrogen gas is also crucial in the field of catalysis. Many catalytic processes involve the interaction of reactants with the surface of a catalyst, and the adsorption of nitrogen gas can provide valuable information about the catalyst's surface properties and accessibility. By studying the physicaladsorption of nitrogen gas on catalyst surfaces, researchers can gain insights into the catalyst's pore structure, surface area, and other characteristics that are essential for optimizing catalytic performance.In the field of material science, the physical adsorption of nitrogen gas is used to characterize the porous structure and surface properties of various materials, such as zeolites, activated carbon, and metal-organic frameworks. The analysis of nitrogen adsorption-desorption isotherms, which describe the relationship between the amount of nitrogen adsorbed and the pressure at a constant temperature, can provide information about the material's surface area, pore size distribution, and other structural features. This information is crucial for the development and optimization of materials with specific applications, such as in catalysis, adsorption, or energy storage.Furthermore, the physical adsorption of nitrogen gas is widely used in the field of environmental science and engineering. Nitrogen-based compounds, such as nitrates or nitrites, can be adsorbed onto various adsorbents, including activated carbon or clay minerals, for the removal of these pollutants from water or soil. This process is particularly important in the treatment of wastewater or the remediation of contaminated sites, where the removal of nitrogen-containing compounds is crucial for environmental protection.In conclusion, the physical adsorption of nitrogen gas is a fundamental phenomenon with a wide range of applications across various scientific and technological fields. From gas separation and purification to gas storage, catalysis, material characterization, and environmental remediation, the understanding and manipulation of nitrogen gas physical adsorption have been instrumental in advancing scientific knowledge and driving technological innovation. As research in this field continues to evolve, new and exciting applications of nitrogen gas physical adsorption are likely to emerge, further expanding its impact on our modern world.。
双排管的使用1
1. Schlenk line，中文一般叫做“希莱克技术”。
它主是用来提供惰性环境以及真空条件的，要是用玻璃仪器组成的，所以实验玻璃器材比较严格。
比如装置用的活塞使用聚四氟乙烯高真空式活塞，接头用O环接口等等。
该装置的主干是Schlenk line玻璃管，一般有两根，一根用于提供真空条件，另一根提供惰性条件。
在其下边连接的是反应烧瓶等。
Schlenk line玻璃管连接到pre-trap以及main-trap玻璃装置。
pre-trap以及main-trap放置在氮气瓶内，用于冷凝挥发性溶剂的。
2.无水无氧系统，即双排管切换来实现3.Schlenk line From Wikipedia, the free encyclopediaA Schlenk line with four ports. The cold trapis on the right.Close-up view, showing the double-oblique stopcock which allows vacuum (rear line) and inert gas (front line) to be selected.Vacuum gas manifold set up:1inert gas in,2inert gas out (to bubbler),3vacuum (To cold traps)4reaction line,5Teflon tap to gas,6Teflon tap to vacuumVacuum gas manifold set up:1inert gas in,2inert gas out (to bubbler),3vacuum (to cold traps),4reaction line,5double oblique stopcock (i.e. a glass tap with 2 separate parallel 'channels/lines' that run diagonal to the axis of the tap.)The Schlenk line (also vacuum gas manifold ) is a commonly-used chemistry apparatus developed by Wilhelm Schlenk . It consists of a dual manifold with several ports.[1]One manifold is connected to a source of purified inert gas , while the other is connected to a high-vacuum pump . The inert gas line is vented through an oil bubbler , while solvent vapors and gaseous reaction products are prevented from 希莱克（双排管）技术2013年4月20日22:21contaminating the vacuum pump through a liquid nitrogen or dry ice/acetone cold trap. Special stopcocks or Teflon taps allow for vacuum or inert gas to be selected without the need for placing the sample on a separate line.Schlenk lines are useful for safely and successfully manipulating air sensitive compounds. The high vacuum is also often used to remove the last traces of solvent from a sample. Vacuum gas manifolds often have many ports and lines, and with care it is possible for several reactions or operations to be run simultaneously.When the reagents are highly susceptible to oxidation, traces of oxygen may pose a problem. Then, for the removal of oxygen below the ppm level, the inert gas needs to be purified by passing it through a deoxygenation catalyst.[2]This is usually a column of copper(I) or manganese(II) oxide which reacts with oxygen traces present in the inert gas. (Source:/wiki/Schlenk_line)4.MG 1026 Schlenk Line OperationAuthor: James M. McCormickLast Update: February 20, 2009（Source:/CHEMLAB_BACKUP/Instrumentation/SchlenkLine/SchlenkLine.htm）IntroductionA schematic diagram of the Schlenk line in MG 1026 is shown in Fig. 1.At the present time it is not truly a Schlenk line because we have no pump attached to the vacuum manifold and we have no mercury bubbler.However, we can still use it to work under a nominally oxygen-free atmosphere by purging the nitrogen manifold, and anything attached to it via the stopcocks, with a stream of nitrogen gas from the cylinder.Figure 1.Schematic diagram of the Schlenk line in MG 1026.OperationThe keys to safe operation of a Schlenk line are 1) always know what the pressure is and never exceed the safe pressure limit, 2) never continue to admit gas to the system when you are not sure where the gas is going, 3) never have the flow rate so fast that mineral oil is blown out of a bubbler into the system or into the hood, and 4) use two hands to turn the glass stopcocks on the manifold.The following assumes that you will be starting up the line when there is no nitrogen gas flow through the system.1) Check that the stopcocks, the inlet control valve, the regulator needle valve and the tank valve are all closed.Do not tighten the inlet control needle valve or the regulator needle valve more than finger e two hands to close the stopcocks.If the stopcocks feel dry or are hard to turn, remove them and apply a light coating of high vacuum silicone grease.Reassemble the stopcocks and carefully turn several times to distribute the grease; repeat process as necessary being careful not to fill the stopcock inlets and outlet with grease.Do not grease any of the valves.2) Open the tank valve. The needle on the tank pressure gauge should rise to indicate the pressure in the tank. If the tank does not have enough nitrogen for your experiment, please change the tank.3) Verify that the outlet pressure gauge reads less than about 15 psi.This should have been set by the last user and not changed. However, it can be reset using the regulator pressure controller. IMPORTANT!Do not use the regulator pressure controller to adjust the flow through the system!4) Open the regulator need valve. One to two turns should be sufficient.5) Open the inlet control needle valve slowly and carefully to start flow through the system, which is indicated by bubbles of nitrogen in the inlet bubbler and bubbles of nitrogen escaping through the exhaust bubbler. A flow rate of about a bubble a second should be sufficient at this point. Use only the inlet control needle valve to change the flow of nitrogen through the manifold!IMPORTANT!If you see bubbles in the inlet bubbler, but none in the exhaust bubbler, immediately check for open stopcocks. If you see no open stopcocks, shut down the flow, carefully open a stopcock to vent the manifold and carefully check the system.6) With a flow of about a bubble per second in the inlet and exhaust bubblers, purge the line with nitrogen. This will take about 20 min, or more. If you can't wait that long, you can increase the flow rate as long as you don't blow mineral oil out of either bubbler (persons doing this will have the chore of cleaning the manifold and will carry a shame that will be passed down even unto the seventh generation). If you turn the flow up, you must remember to turn it down.7) Once the manifold is flushed you can open the appropriate stopcock to flush your system which will be attached to one of the ports on themanifold via red rubber vacuum tubing. There are several ways to do this.•Attach the vacuum tubing to your system (via a gas inlet adapter), but leave the system open in some way so that you can blow nitrogen through the system. If you choose this method, you will need to increase the nitrogen flow, but remember to turn it down once you've closed the system.•One could also attach a mineral oil bubbler, or a bubbler containing a different liquid, to the system (again using a gas inlet adapter) and just continue flowing nitrogen at a normal rate.•Another way to purge your system is to attach a glass tube (or Pasteur pipette) to the hose and simply insert it into the system through an open port. This is a useful way to quickly to remove most of the air from your system. It takes about 10-20 min to remove most of the air (depending on your solvent), and reduces oxygen present in the solvent to a level that is low enough for most work, but it can evaporate a good deal of solvent.8) When your system has been purged with nitrogen (this may take anywhere from a few minutes to 20 minutes), you can close it. Don't forget to turn down the nitrogen flow immediately after you do this! As long as there is nitrogen flow through the manifold (bubbles at both the inlet and exhaust bubblers), your system will be under nitrogen. Note that as long as the exhaust bubbler is open to the air the system is not closed!•If you will be connecting/disconnecting things from your system during the course of your experiment, turn up the nitrogen flow while making the change using the inlet control needle valve. Remember to turn down the flow again once you are finished making the change. •If you will be heating your system under nitrogen, set the flow rate (1 or 2 bubbles per second is usually sufficient) before starting to heat and do not change the flow rate during reflux. Take care when refluxing that you do not blow your reaction up into the manifold. People who do this will share the same fate as those who blow mineral oil out of the bubblers.9) When your experiment is finished, close the stopcock to your system (use two hands) and remove it from the line. If someone else will be using the line shortly after you, you can leave it with all the stopcocks closed and a nitrogen flow of 1 bubble per second. If nobody will be using the line, close (in order) the inlet control needle valve, the regulator needle valve and the tank valve. Remember to close the inlet control needle valve and the regulator needle valve no more than finger tight. Do not change the regulator pressure control valve.5. /inorganic/glassware/vacline.html源文档</s/blog_6d554df701012hhi.html>。
纳米金对抗氧化剂的催化氧化及其活性的影响
实验研究CHINESE COMMUNITY DOCTORS 由于在生物医学领域的广泛应用，纳米材料已经成为目前的研究热点。
金纳米材料(纳米金)是指直径在1～100nm范围的金颗粒，具有良好的生物相容性、尺寸效应、表面效应以及独特的光学性质[1]，在工业催化、生物医药、肿瘤治疗、生物检测等领域具有广泛的应用[2-5]。
目前的研究认为纳米金的尺寸、形状、表面配体以及作用的细胞株类型等因素决定了其毒理学性质[6-8]。
但是，金纳米颗粒的毒理学机制尚未成熟，人们对于纳米金与活性分子之间的相互作用及其生物学效应知之甚少[9，10]。
针对金纳米颗粒的表面效应，本文研究了纳米金对不同种类抗氧化剂氧化进程的影响，并分析了其作用机制，为金纳米颗粒的合理应用提供了实验基础。
资料与方法试剂与仪器：氯金酸、碳酸钾、硼氢化钠购自国药集团化学试剂有限公司；抗坏血酸(AA)、表儿茶素(EC)、2，2，6，6-Tetramethylpiperidine (TEMP)、3-Carbamoyl-2，5-dihydro-2，2，5，5-tetramethyl-1H-pyrrol-1-yloxyl(CTPO)购自Sigma 公司；ESR 自旋捕获剂5，5-Dimethyl -1-pyrroline-N-oxide (DMPO)、5-tert-Butoxycarbonyl -5-meth-yl-1-pyrroline-N-oxide(BMPO)购自Dojin-do Molecular Technologies 公司；实验用水均为超纯水装置净化的3次去离子水，电阻率＞18.2MΩ·cm。
纳米颗粒的形貌使用FEI 公司的Tecnai G2Spirit BioTWIN 透射电子显微镜(TEM)表征；紫外-可见光谱使用岛津公司的UV-3600紫外光谱仪测定；活性氧自由基使用Bruker 公司的电子自旋共振光谱(ESR)检测。
金纳米颗粒的制备：分别配制1%的氯金酸溶液(溶液1)、0.2mol/L 的碳酸钾溶液(溶液2)和0.02mol/L 硼氢化钠溶液(溶液3)。
植物内生固氮菌及其固氮机理研究进展
生物技术进展2022年第12卷第1期17~26Current BiotechnologyISSN 2095‑2341进展评述Reviews植物内生固氮菌及其固氮机理研究进展王玉虎，赵明敏，郑红丽*内蒙古农业大学园艺与植物保护学院，呼和浩特010019摘要：氮素是植物生长必不可少的元素，植物内生固氮菌不仅能够在植物体内产生氮素以供植物利用，而且在自然界氮素循环过程中发挥积极作用，对农业可持续发展具有重要意义。
近年来，植物内生固氮菌逐渐成为研究热点。
由植物内生固氮菌的发现、作物共生、侵入途径、固氮机理、促生作用机制等方面系统地综述了植物内生固氮菌的研究进展，探讨了植物内生固氮菌新的研究思路以及一些尚未解决的问题，以期为植物内生固氮菌及生物固氮研究提供参考。
关键词：内生固氮菌；固氮酶；固氮机理；生物固氮DOI ：10.19586/j.2095‑2341.2021.0126中图分类号：Q939.11+3文献标志码：AResearch Progress on Plant Endophytic Nitrogen‑fixing Bacteria and Their Nitrogen Fixation MechanismWANG Yuhu ，ZHAO Mingmin ，ZHENG Hongli *College of Horticulture and Plant Protection ，Inner Mongolia Agricultural University ，Hohhot 010019，ChinaAbstract ：Nitrogen is an essential element for plant growth.Plant endophytic nitrogen -fixing bacteria can not only produce nitrogen in the plant body for plant utilization ，but also play an active role in the natural nitrogen cycle ，which has important significance for the sustainable development of agriculture.The research on endogenous nitrogen -fixing bacteria has gradually become research hotspot in recent years.This article systematically reviewed the research progress of plant endophytic nitrogen -fixing bacteria from many aspects ，such as the discovery of plant endophytic nitrogen -fixing bacteria ，crop symbiosis ，invasion pathways ，nitrogen -fixing mechanism ，and growth -promoting mechanism.In addition ，new research ideas of plant endophytic nitrogen -fixing bacteria and some unresolved problems were discussed.This paper was expected to provide reference for research on plant endophytic nitrogen -fixing bacteria and biological nitrogen fixation.Key words ：endophytic nitrogen -fixing bacteria ；nitrogenase ；nitrogen fixation mechanism ；biological nitrogen fixation植物内生固氮菌（endophytic diazotroph ）是指与宿主植物进行联合固氮并且定殖于植物体内的一类微生物[1]。
蜂窝式脱硝催化剂再生技术研究进展
|2021,Vol.38No.05化学金住的工轻Chemistry&Bioengineering doi：10.3969/j.issn.1672-5425.2021.05.003古玲霞，刘少文•蜂窝式脱硝催化剂再生技术研究进展[J]•化学与生物工程,2021,38(5)=14-18,25.GU L X,LIU S W.Research progress in regeneration technology of honeycomb denitration catalyst[J].Chemistry&Bioengineering, 2021,38(5):14-18,25.蜂窝式脱硝催化剂再生技术研究进展古玲霞，刘少文*(武汉工程大学化工与制药学院绿色化工过程教育部重点实验室，湖北武汉430200)摘要：煤燃烧会产生大量的氮氧化物(NOJ等大气污染物，随着燃煤污染防治要求越来越严格，脱硝催化剂得到了广泛应用，每年会产生大量的失活■脱硝催化剂，催化剂的再生技术开发引起了人们的高度重视。
简介了脱硝催化剂的应用情况，分析了蜂窝式脱硝催化剂失活的原因，综述了蜂窝式脱硝催化剂再生技术研究进展，并对今后蜂窝式脱摘催化剂再生技术进行了展望。
关键词：蜂窝式脱硝催化剂；失活；再生技术中图分类号:TQ426X511文献标识码：A文章编号：1672-5425(2021)05-0014-05Research Progress in Regeneration Technology of Honeycomb Denitration CatalystGU Lingxia,LIU Shaowen*(Key Laboratory for Green Chemical Process of Ministry of Education, School of Chemical Engineering and Pharmay,Wuhan Institute of Technology,Wuhan430200,China} Abstract:Coal combustion can produce a large number of nitrogen oxides(N(X)and other atmospheric pollutants,and coal pollution prevention and control requirements have been tightened.Therefore,denitration catalysts have been widely used,however,a large number of deactivated denitration catalysts are generated every year,and the development o£catalyst regeneration technology has attracted people's high attention.We briefly introduce the application situation of denitration catalyst,and analyze the reasons of deactivation of honeycomb denitration catalyst.Moreover,we summarize the research progress of regeneration technology of honeycomb denitration catalyst,and put forward prospect in the regeneration technology of honeycomb denitration catalyst in the future.Keywords:honeycomb denitration catalyst；deactivation；regeneration technology脱硝主要发生在燃煤行业，煤燃烧会产生大量的空气污染物,如细颗粒物、SO?、氮氧化物(NOJ等，其中NO’通常采用脱硝催化剂加以脱除。
惰气熔融-红外吸收
分析测试新成果 (39 ~ 46)惰气熔融-红外吸收/热导法同时测定无烟煤中氮和氢王 琳1，王 楠1，沈峰满2（1. 东北大学 分析测试中心，辽宁 沈阳 110819；2. 东北大学 冶金学院，辽宁 沈阳 110819）摘要：首次使用惰气熔融-红外吸收/热导法实现无烟煤中氮、氢元素的同时、快速、准确测定. 探究分析条件，发现当称样量为0.030 0 g ，分析功率为5 500 W ，氮元素的积分延迟时间为15 s ，集成时间为55 s ，氢元素的积分延迟时间为5 s ，集成时间为85 s ，且使用石墨套埚时，氮氢元素的释放最完全、合理. 方法中氮、氢校准曲线的相关系数分别为0.994 9、0.994 0，检出限分别为0.321%、0.189%，定量限分别为0.326%、0.194%，精密度分别为3.60%、0.63%，满足线性关系及方法要求. 惰气熔融-红外吸收/热导法重复性好、高效便捷、操作和维护简单，可用于无烟煤中氮、氢元素的定量检测.关键词：惰气熔融；红外吸收/热导法；无烟煤；氮；氢中图分类号：O657. 3 文献标志码：B 文章编号：1006-3757（2024）01-0039-08DOI ：10.16495/j.1006-3757.2024.01.007Simultaneous Determination of Nitrogen and Hydrogen in Anthracite by Inert Gas Melting-Infrared Absorption/Thermal Conductivity MethodWANG Lin 1， WANG Nan 1， SHEN Fengman2（1. Analysis and Measurement Centre , Northeastern University , Shenyang 110819, China ；2. School ofMetallurgy , Northeastern University , Shenyang 110819, China ）Abstract ：The contents of nitrogen and hydrogen in anthracite were simultaneously, rapidly and accurately determined by the inert gas melting-infrared absorption/thermal conductivity method. A series of experiments were studied. The results indicated that the most complete and reasonable release of nitrogen and hydrogen was achieved when the sample was 0.030 0 g, the analysis power was 5 500 W, the integration delay time of nitrogen was 15 s, the integration time of nitrogen was 55 s, the integration delay time of hydrogen was 5 s, the integration time of hydrogen was 85 s, and the graphite sleeve crucible was used. The correlation coefficients of calibration curves of nitrogen and hydrogen were 0.994 9and 0.994 0, respectively. The limits of detection were 0.321% and 0.189%, the limits of quantification were 0.326% and 0.194%, and the precision were 3.60% and 0.63%, respectively, which met the requirements of linearity and method. The inert gas melting-infrared absorption/thermal conductivity method is reproducible, efficient and convenient, easy to operate and maintain, and can be used for the quantitative determination of nitrogen and hydrogen in anthracite.Key words ：inert gas melting ；infrared absorption/thermal conductivity method ；anthracite ；nitrogen ；hydrogen自2020年我国提出碳达峰、碳中和的发展目标以来[1]，我国的能源、经济等发展始终围绕碳排放、绿色清洁等话题. 煤是工业原料之一，素来被称为“工业之母”，是世界工业、制造业、经济、民生等的重要支撑，其用途广泛，在新材料制备、化工生产、生活供暖、交通出行、发电等方面有着不可替代的作用. 我国属于煤矿矿产丰富的国家[2]，煤、石油、天然气是重要的能源，特点是“富煤、贫油、少气”[3].收稿日期：2023−10−11； 修订日期：2023−12−18.基金项目：国家自然科学基金资助项目 (51974073) [National Natural Science Foundation of China (51974073)]作者简介：王琳（1990−），女，实验师，主要从事气体成分分析等化学分析，E-mail ：****************.第 30 卷第 1 期分析测试技术与仪器Volume 30 Number 12024年1月ANALYSIS AND TESTING TECHNOLOGY AND INSTRUMENTS Jan. 2024煤根据品种及品质的不同，分为烟煤、无烟煤、焦炭等，并应用于不同行业，其中无烟煤因其燃烧无烟、煤化程度高、含碳量高、热值高、挥发分低等特点，普遍用于燃料及燃料电池、先进碳材料[4-7]、催化剂[8]、吸附剂[9-10]、滤料、民用煤等. 而据统计显示，我国空气污染源中的粉尘、PM2.5、SO2及NO x等大部分来自于民用煤燃烧的排放[11]，因此加强对无烟煤的质量监测，是提升煤炭质量、发展低碳与绿色能源的重要环节.煤炭的检测标准溯源到上世纪60年代，检测指标一般包括工业分析[12]（水分、灰分、挥发分、固定碳）、元素分析[13-15]（C、S、O、N、H）、有价元素分析[16-17]（As、Ga、Se、Ge等）、阴离子[18]（氟等）等. 其中无烟煤中的氮元素在燃烧后会形成NO x，对人类及居住环境污染影响较大[11]. 无烟煤中氢元素含量的多少，代表了热值的大小. 因此准确快速测定无烟煤中氮、氢含量对煤炭质量控制，煤炭行业的检验检测、标准制定、能源开发及环境保护等均具有重要意义.对于无烟煤中氮、氢元素的检测，通常使用半微量开氏法和半微量蒸汽法[19]、高温燃烧-检测器测定法[14, 20]测定无烟煤中的氮含量，采用三节炉法、二节炉法[13]、电量-重量法[21]、高温燃烧-检测器测定法[14]测定无烟煤中的氢含量. 其中三节炉法、二节炉法、电量-重量法均存在硫、氯等元素的干扰，需使用铬酸铅、银丝、二氧化锰等试剂消除干扰，污染较大且成本高. 随着科技的进步，仪器法逐渐被用于测定无烟煤中的氮、氢元素含量，现有的仪器法[22]原理是将无烟煤在氧气下燃烧，对燃烧生成的H2O、N2气体进行检测. 但该法存在燃烧炉/管升降温时间长、分析时间长、维护复杂、耗材昂贵等缺点. 而以惰气熔融-红外吸收/热导法为分析原理设计的氧氮氢分析仪通常用于陶瓷、粉末[23]、钢铁[24]等无机材料中氧、氮、氢元素的测定，并以快速、精准的优势成为冶金、材料等领域以及检验检测机构在气体元素分析方面的常用仪器. 但目前为止，未见其应用于无烟煤类产品的检测工作中，其在使用中无需强酸、重金属等试剂，具有无需等待升降温、分析时间短、样品前处理简易、维护相对简单等优势，满足绿色、安全、快速、准确分析的要求，因此本文首次尝试将惰气熔融-红外吸收/热导法应用于无烟煤中氮、氢元素的检测.1 试验部分1.1 仪器与试剂氧氮氢分析仪：美国力可公司，ONH836；天平：赛多利斯，SQP；石墨套埚（内坩埚加外坩埚）、石墨标准坩埚、镍嚢，LECO公司；有机元素分析仪：德国元素公司，Vario MACRO cube.氦气（99.999%），氮气（99.5%），沈阳顺泰特种气体有限公司；无烟煤标准物质：ZBM093、ZBW112A、ZBM095A，济南众标科技有限公司生产；GBW11104j，国家煤炭质量监督检验中心；GBW11108o，山东省冶金科学研究院. 对氨基苯磺酰胺（C6H8N2O2S）、WO3，德国元素公司；未知样品为某学生客户日常送检的无烟煤样品.1.2 试验原理在惰性气体氦气保护下，样品置于上下电极间的石墨坩埚中，经过坩埚脱气、吹扫、脉冲炉通电，上、下电极及石墨坩埚形成电路并加热，使待测样品完全熔融，N、H元素分别以N2、H2分子形式释放，随载气氦气流经热的氧化铜催化剂，H2被完全氧化成H2O，N2、H2O一起进入红外检测池，根据H2O的特征红外吸收波长，检测得到氢元素的含量，之后H2O被高氯酸镁等过滤试剂吸收，N2进入热导检测池完成氮元素的测定，其原理图如图1所示.样品上电级红外检测池检测 H2O热导检测池检测 N2坩埚下电极脉冲熔融炉N2N2H2催化剂H2OH2O图1 氧氮氢分析仪测定氮、氢的工作原理图Fig. 1 Working principle diagram ofOxygen/Nitrogen/Hydrogen Analyzer determined nitrogenand hydrogen1.3 试验方法1.3.1 准备工作将标准物质、待测样品置于110 ℃洁净的烘箱中烘干2 h，保证粒度在0.074 mm以下，然后再置40分析测试技术与仪器第 30 卷于干燥器中冷却备用.对氧氮氢分析仪进行彻底维护，包括上电极、下电极、投样口的清扫清洁，催化剂、过滤试剂等试剂的更换，并通过漏气检查，保证仪器的气密性.1.3.2 试验步骤打开稳压电源、氧氮氢分析仪主机及软件，将下电极升高，在氦气保护模式下进行仪器预热至少1 h，预热完成后打开氦气至流速为450 mL/min，开通冷却水，使检测器保持在稳定的工作温度. 本方法以镍嚢及空白石墨套锅作为空白，分别称取0.010 0~0.100 0 g（精确到±0.000 3 g）的样品，小心倾倒于镍嚢内，等待投样，设置4 500~6 000 W的分析功率，对比石墨套埚与石墨标准坩埚的分析效果，分别设置0~15 s的分析延迟时间、50~85 s数据集成时间等仪器参数. 开始测试后进行投放样品、取下坩埚、更换新的内坩埚、脱气、吹扫等操作，依次进行空白、标准物质及未知样品的测试，建立标准曲线，并对方法进行检出限、定量限、精密度等试验验证.1.3.3 未知样品对比试验本文使用有机元素分析仪作为未知样品测试的对比方法，并命名为方法1. 对有机元素分析仪（CHNS模式）的燃烧管进行清理并更换试剂及灰分坩埚，还原管内铜及银丝重新装填，酒精擦拭干净后放回到炉子内，通高纯氦气，流速为600 mL/min，室温检漏通过后，分别升至1 150、850 ℃工作温度下吹扫4 h后进行试验. 使用仪器自带标准曲线，以75 mg的锡纸包裹，称取25 mg的对氨基苯磺酰胺作为“run”和漂移标准物质进行曲线校正，待测样品称样量为50 mg，加入WO3助熔，75 mg锡纸包裹，使用工具压除空气后置于自动进样器中进样，试样在1 150 ℃下通高纯氧气燃烧，850 ℃下催化还原，释放出N2和H2O，进入相应检测池分析检测，经过“吹扫-捕集”吸附解析的分离过程，得到氮、氢的分析数据，完成检测.2 结果与讨论2.1 进样方式的确定本试验采用直投法进样，对于粉末类样品以此方式进样时，会造成进样系统污染、进样量减少、分析数据偏低等问题，为避免因进样造成的分析误差，需采用镍嚢作为样品包裹体，保证进样量的准确性及释放完全性.2.2 进样量的确定样品的进样量会影响熔融效果，使用标准物质ZBM095A作为待测样品，对比0.010 0、0.020 0、0.030 0、0.040 0、0.050 0、0.060 0、0.080 0、0.100 0 g 进样量对氮、氢元素释放效果的影响. 由图2可见，随着进样量的增加，氮质量比在进样量为0.010 0~ 0.030 0 g时的测定结果变化不大，而在0.0300 g时出现拐点呈下降趋势，随着进样量的继续增加，由于释放条件不足，氮质量比下降，因此氮的最佳进样量为0.0300 g. 氢质量比随进样量增加，先呈明显上升趋势，在进样量为0.030 0 g时，氢质量比达到了最高点，而随着进样量的继续增大，氢质量比缓慢降低，在进样量大于0.060 0 g时，氢质量比迅速下降. 由此可见，0.0300 g是其最佳进样量. 产生该现象的原因可能是进样量较低时，样品分析浓度不够，导致氢元素质量比偏低，而进样量过高时，样品的分析条件不足以使氢完全释放，氢元素质量比降低，且就仪器本身的检测范围而言，氢的测量上限绝对质量为0.002 5 g，因此对于标准物质ZBM095A 的氢元素质量比的测定，当进样量超过0.050 0 g时，检测池处于饱和状态，无法正常检测. 因此，0.030 0 g 为该方法的最佳进样质量.4.54.03.53.02.52.01.51.00.500.020 00.040 00.060 0NH0.080 00.100 0m/g质量比/%图2 不同进样量下氮、氢的测试结果Fig. 2 Test results of nitrogen and hydrogen underdifferent sample masses2.3 分析功率的确定在氮、氢元素分析中，分析功率是决定样品释放的重要参数. 本试验依次设置4 500、5 000、5 500、6 000 W的功率梯度，观察功率对于无烟煤中氮、氢元素检测的影响. 图3为氮、氢的测试值随功率变化的关系图. 由图3可见，当功率较低，在4 500、5 000 W时，氮、氢元素质量比偏低，说明过低的功第 1 期王琳，等：惰气熔融-红外吸收/热导法同时测定无烟煤中氮和氢41率不足以使无烟煤完全熔融释放，这与无烟煤本身含碳量高、燃点高的特性一致. 但当功率为6 000 W 时，质量比再次下降，这是因为功率过高，导致氮、氢元素过早溢出，数据捕捉不及时，导致数据偏低.当分析功率为5 500 W 时，氮、氢元素的释放最完全，测定值最高. 由此可见，无烟煤的最佳分析功率为5 500 W.2.4 分析坩埚的对比氮、氢元素分析的样品载体一般分为石墨套埚（外坩埚加内坩埚）和标准坩埚. 本试验对比二者的分析效果，观察图4（a ）的氮元素及图4（b ）的氢元素在使用不同坩埚时的测定谱图，可发现氮、氢元素在使用石墨套埚得到的测定值明显高于标准坩埚，说明石墨套埚的分析效果优于标准坩埚. 究其原因，标准坩埚对比石墨套埚来说相对单薄，在5 500 W 的高功率下其承压能力小，甚至存在标准坩埚被烧漏或者断裂的情况，因而标准坩埚的使用会导致数据偏低，对于无烟煤这类燃点高、熔融产生热量大的样品来说，双层结构的套埚更适用. 因此，本试验选用石墨套埚作为分析坩埚.2.5 分析参数的设定（包括分析延迟时间、数据集成时间）本方法对仪器分析参数（分析延迟时间、数据集成时间）进行了探究. 对比了15、10、5、0 s 四种延迟时间，观察图5（a ）可见，15 、10 s 时氢的出峰过早、不完整且峰形不佳，导致氢元素的数据捕集不完全，测试数据偏低. 当调整为5 s 时，氢峰的前端有平缓的基线，0 s 时出峰过缓. 因此，5 s 是合理的延迟时间. 由图5（b ）可见，氮的测试值随延迟时间的增加而增大，其延迟时间设置为15 s 较合理.对于出峰不完全的问题，本试验采用将数据集成时间延长的方式，分别设置为55、65、75、80、85 s ，观察图6（a ）发现，当集成时间为55、65、75 s 时，氢峰的末端均未回到基线的位置，数据偏低. 80 s 时谱线回到基线，85 s 时形成相对完整的正态分布峰，与图6（b ）的数据趋势吻合. 同时观察图6（b ）发现，氮的集成时间为55s 数据更合理. 因此本方法选择氮的延迟时间为15 s 、集成时间为55 s ，氢的延迟时间为5 s 、集成时间为85 s 为最佳分析参数.2.6 标准曲线建立及检出限测定无烟煤中的氮、氢元素含量范围较宽泛，单点校准的方式并不适用. 本文采用建立标准曲线的校准方式，在称样质量为0.030 0 g 、分析功率为5 500W ，氮、氢元素延迟时间分别为15、5 s ，捕集时间分别为55、85 s ，使用石墨套埚的试验条件下，选择有证标准物质ZBM093、GBW11104j 、GBW11108o 、2.754.34.24.14.03.92.702.652.602.554 5005 000N H5 5006 000P /W质量比/%质量比/%图3 分析功率的探究试验Fig. 3 Test results of nitrogen and hydrogen underdifferent analytical powers100(a)608040积分强度石墨套锅标准坩埚2000102030t /s405060100(b)608040积分强度石墨坩埚标准坩埚2000102030t /s405060图4 石墨套埚与标准坩埚的确定试验(a)不同坩埚对氮元素的测试谱图，(b)不同坩埚对氢元素的测试谱图Fig. 4 Comparison of test results between graphite sleeve pote and standard crucible (a) spectra of nitrogen in different crucibles, (b) spectra of hydrogen in different crucibles42分析测试技术与仪器第 30 卷ZBW112A 建立标准曲线，其认定值及测量值结果如表1所列. 氮、氢元素的线性方程分别为：Y =2.098 404 22X −0.000 200 66、Y =0.789 376 46X −0.000 044 57，相关系数分别为0.994 9、0.994 0，满足线性关系. 对空白坩埚连续测试11次，得到氮、氢元素的平均值分别为0.318 9%、0.186 9%，以该结果与3倍标准偏差之和作为检出限，分别为0.321%、0.189%，以平均值与10倍标准偏差之和作为定量限，分别为0.326%、0.194%，结果如表2所列，表明该方法检测范围较宽，适用于无烟煤中氮、氢元素的定量检测.2.7 方法的准确度、精密度测试精密度测试是验证方法可靠性的重要指标，本试验使用有证无烟煤标准物质ZBM095A 进行精密度测试，平行测定7次，并计算其精密度. 如表3所列，其氮、氢元素的测定平均值分别为1.30%、3.30%，由表1可知，其认证值分别为1.31%±0.07%、3.23%±0.10%，因此该方法准确度较好. 经计算，氮、氢的精密度分别为3.60%、0.63%，满足方法精密度要求. 由此可见该方法准确可靠.表 1 标准物质及其认证值、测量值Table 1 Certified and measured values of standardsubstances/%标准物质NH 认证值测量值认证值测量值ZBM0930.56±0.060.563 3.01±0.12 2.92GBW11104j 0.94±0.070.929 2.64±0.15 2.71GBW11108o 1.30±0.06 1.30 4.58±0.13 4.59ZBW112A 1.10±0.06 1.12 3.78±0.10 3.79ZBM095A1.31±0.071.303.23±0.103.3010015 s 10 s 5 s 0 s(a)8060积分强度402005101520253035t /s 404550556065702.655.04.03.02.01.00N H(b)2.602.552.50质量比/%质量比/%2.452.402.3551015t /s图5 氮、氢的分析延迟时间对比试验(a) 不同延迟时间下氢的测试谱图， (b)延迟时间对氮、氢的影响Fig. 5 Comparison test of analysis delay times of nitrogen and hydrogen(a) spectra of hydrogen in different delay times, (b) effect of delay times on nitrogen and hydrogen100 2.705.04.94.84.74.62.682.662.642.622.6055606570758085909585 s 80 s 75 s 65 s 55 s806040积分强度质量比/%质量比/%20002040t /st /s6080100(a)(b)图6 氮、氢的集成时间对比试验(a)不同集成时间下氢的测试谱图， (b)集成时间对氮、氢的影响Fig. 6 Comparison test of integration times of nitrogen and hydrogen(a) spectra of hydrogen in different integration times, (b) effect of integration times on nitrogen and hydrogen第 1 期王琳，等：惰气熔融-红外吸收/热导法同时测定无烟煤中氮和氢432.8 未知样品测试对日常送检的无烟煤样品进行抽检，并标号为样品1、样品2，使用方法1与本方法进行对比，随试验进行ZBM095A的测试. 分别平行测定7次，其测试结果如表4所列. 由表可见，方法1测得样品1、样品2、ZBM095A中氮的平均值分别为0.096 6%、1.086%、1.30%，相对标准偏差（RSD）分别为2.67%、1.75%、3.60%. 氢的平均值分别为2.899%、3.312%、3.30%，RSD分别为1.90%、1.50%、0.63%. 本方法测得样品1、样品2、ZBM095A中氮的平均值分别为0.094 6%、1.067%、1.25%，RSD分别为2.99%、1.69%、3.90%. 氢的平均值分别为2.927%、3.300%、3.20%，RSD分别为1.87%、1.56%、0.72%. 对比两种方法，准确度与精密度均能够满足试验要求，再次证实本文建立的方法适用于无烟煤中的氮、氢两种元素的定量测定.表 3 ZBM095A的精密度试验Table 3 Precision test of ZBM095A/%元素测定值平均值RSDN 1.28、1.26、1.34、1.35、1.36、1.30、1.24 1.30 3.60H 3.30、3.32、3.33、3.29、3.29、3.33、3.28 3.300.63表 4 两种方法测试未知样品的对比试验Table 4 Comparison of two methods for testing unknown samples/%样品方法1平均值方法1 RSD本方法平均值本方法RSD N H N H N H N H样品10.096 6 2.899 2.67 1.900.094 6 2.927 2.99 1.87样品 2 1.086 3.312 1.75 1.50 1.067 3.300 1.69 1.56 ZBM095A 1.30 3.30 3.600.63 1.25 3.20 3.900.723 结论（1）本文首次将惰性气体熔融-红外吸收/热导法应用于无烟煤类产品的检测中，该方法满足同时、快速、准确的特点，减少了强酸化学试剂的使用，体现了绿色化学宗旨.（2）建立了无烟煤中氮、氢元素定量测试的方法，为煤炭行业的检验检测、标准制定、贸易等提供参考.（3）拓展了氧氮氢分析仪的使用范围，在有色金属、高温合金、难熔金属、稀土、陶瓷、矿石等材料的使用范围之外，增加了无烟煤类产品的使用.参考文献：习近平. 在第七十五届联合国大会一般性辩论上的讲话[N]. 人民日报, 2020-09-23(3).［ 1 ］元雪芳, 任恒星, 郭鑫, 等. 不同物质对无烟煤生物转化的影响研究[J].煤化工，2022，50（5）：79-82.[YUAN Xuefang, REN Hengxing, GUO Xin, et al.Study on impact of adding different substances on bio-transformation of 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Dissolved Organic Matter Biogeochemistry, Dynamics, and Environmental Significance in Soils
C H A P T E R O N EDissolved Organic Matter:Biogeochemistry,Dynamics,and Environmental Significance in SoilsNanthi S.Bolan,*,†Domy C.Adriano,‡Anitha Kunhikrishnan,*,†Trevor James,§Richard McDowell,}and Nicola Senesi #Contents1.Introduction32.Sources,Pools,and Fluxes of Dissolved Organic Matter in Soils 53.Properties and Chemical Composition of Dissolved Organic Matter in Soils133.1.Structural components133.2.Fulvic acid—The dominant component 153.3.Elemental composition204.Mechanisms Regulating Dynamics of Dissolved Organic Matter in Soils204.1.Sorption/complexation 234.2.Biodegradation 274.3.Photodegradation 284.4.Leaching295.Factors Influencing Dynamics of Dissolved Organic Matter in Soils 305.1.Vegetation and land use 315.2.Cultivation325.3.Soil amendments 335.4.Soil pH366.Environmental Significance of Dissolved Organic Matter in Soils 376.1.Soil aggregation and erosion control 376.2.Mobilization and export of nutrients386.3.Bioavailability and ecotoxicology of heavy metals43Advances in Agronomy,Volume 110#2011Elsevier Inc.ISSN 0065-2113,DOI:10.1016/B978-0-12-385531-2.00001-3All rights reserved.*Centre for Environmental Risk Assessment and Remediation (CERAR),University of South Australia,Australia {Cooperative Research Centre for Contaminants Assessment and Remediation of the Environment (CRC CARE),University of South Australia,Australia {University of Georgia,Savannah River Ecology Laboratory,Drawer E,Aiken,South Carolina,USA }AgResearch,Ruakura Research Centre,Hamilton,New Zealand }AgResearch,Invermay Agricultural Centre,Mosgiel,New Zealand #Department of Agroforestal and Environmental Biology and Chemistry,University of Bari,Bari,Italy 12Nanthi S.Bolan et al.6.4.Transformation and transport of organic contaminants506.5.Gaseous emission and atmospheric pollution587.Summary and Research Needs607.1.Macroscale(landscape to global)617.2.Microscale(water bodies and soil profile)617.3.Molecular scale(carbon fractions,organic acids,andmicroorganisms)61 Acknowledgments62 References62“Dissolved organic matter comprises only a small part of soil organicmatter;nevertheless,it affects many processes in soil and water includ-ing the most serious environmental problems like soil and waterpollution and global warming.”(Kalbitz and Kaiser,2003)AbstractDissolved organic matter(DOM)is defined as the organic matter fraction in solution that passes through a0.45m m filter.Although DOM is ubiquitous in terrestrial and aquatic ecosystems,it represents only a small proportion of the total organic matter in soil.However,DOM,being the most mobile and actively cycling organic matter fraction,influences a spectrum of biogeochemical pro-cesses in the aquatic and terrestrial environments.Biological fixation of atmo-spheric CO2during photosynthesis by higher plants is the primary driver of global carbon cycle.A major portion of the carbon in organic matter in the aquatic environment is derived from the transport of carbon produced in the terrestrial environment.However,much of the terrestrially produced DOM is consumed by microbes,photo degraded,or adsorbed in soils and sediments as it passes to the ocean.The majority of DOM in terrestrial and aquatic environ-ments is ultimately returned to atmosphere as CO2through microbial respira-tion,thereby renewing the atmospheric CO2reserve for photosynthesis.Dissolved organic matter plays a significant role in influencing the dynamics and interactions of nutrients and contaminants in soils and microbial functions, thereby serving as a sensitive indicator of shifts in ecological processes.This chapter aims to highlight knowledge on the production of DOM in soils under different management regimes,identify its sources and sinks,and integrate its dynamics with various soil processes.Understanding the significance of DOM in soil processes can enhance development of strategies to mitigate DOM-induced environmental impacts.This review encourages greater interactions between terrestrial and aquatic biogeochemists and ecologists,which is essential for unraveling the fundamental biogeochemical processes involved in the synthesis of DOM in terrestrial ecosystem,its subsequent transport to aquatic ecosystem, and its role in environmental sustainability,buffering of nutrients and pollutants (metal(loid)s and organics),and the net effect on the global carbon cycle.Dissolved Organic Matter31.IntroductionThe total organic matter(TOM)in terrestrial and aquatic environ-ments consists of two operationally defined phases:particulate organic matter(POM)and dissolved organic matter(DOM).For all practical purposes,DOM is defined as the organic matter fraction in solution that passes through a0.45m m filter(Thurman,1985;Zsolnay,2003).Some workers have used finer filter paper(i.e.,0.2m m)in an effort to separate “true”DOM from colloidal materials,but0.45m m filtration appears to be standard(Buffle et al.,1982;Dafner and Wangersky,2002).In some litera-ture,the term dissolved organic carbon(DOC)is used,which represents total organic carbon in solution that passes through a0.45m m filter (Zsolnay,2003).Since carbon represents the bulk of the elemental compo-sition of the organic matter(ca.67%),DOM is often quantified by its carbon content and referred to as DOC.In the case of studies involving soils,the term water-soluble organic matter(WSOM)or water-extractable organic matter(WEOM)is also used when measuring the fraction of the soil organic matter(SOM)extracted with water or dilute salt solution(e.g.,0.5 M K2SO4)that passes through a0.45m m filter(Bolan et al.,1996;Herbert et al.,1993).Recently,the distinction between POM and DOM in the marine environment is being replaced by the idea of an organic matter continuum of gel-like polymers,replete with colloids and crisscrossed by “transparent”polymer strings,sheets,and bundles,from a few to hundreds of micrometers—referred to as oceanic“dark matter”(Dafner and Wangersky,2002).Dissolved organic matter is ubiquitous in terrestrial and aquatic ecosys-tems,but represents only a small proportion of the total organic matter in soil(McGill et al.,1986).However,it is now widely recognized that because DOM is the most mobile and actively cycling organic matter fraction,it influences a myriad of biogeochemical processes in aquatic and terrestrial environments as well as key environmental parameters (Chantigny,2003;Kalbitz et al.,2000;McDowell,2003;Stevenson, 1994;Zsolnay,2003).Dissolved organic carbon has been identified as one of the major components responsible for determining the drinking water quality.For example,DOM leads to the formation of toxic disinfection by-products(DBPs),such as trihalomethanes,after reacting with disinfectants (e.g.,chlorine)during water treatment.Similarly,DOM can be related to bacterial proliferation within the drinking water distribution system.There-fore,the control of DOM has been identified as an important part of the operation of drinking water plants and distribution systems(Volk et al., 2002).In aquatic environments,the easily oxidizable compounds in the DOM can act as chemical and biological oxygen demand compounds, thereby depleting the oxygen concentration of aquifers and influencing4Nanthi S.Bolan et al. aquatic biota(Jones,1992).Dissolved organic carbon can act as a readily available carbon source for anaerobic soil organisms,thereby inducing the reduction of nitrate(denitrification)resulting in the release of green house gases,such as nitrous oxide(N2O)and nitric oxide(NO),which are implicated in ozone depletion(Siemens et al.,2003).Organic pesticides added to soil and aquifers are partitioned preferentially onto DOM,which can act as a vehicle for the movement of pesticide residues to groundwater (Barriuso et al.,1992).Similarly,the organic acids present in the DOM can act as chelating agents,thereby enhancing the mobilization of toxic heavy metals and metalloids[metal(loid)s](Antoniadis and Alloway,2002).The release and retention of DOM are the driving forces controlling a number of pedological processes including podzolization(Hedges,1987).Biological fixation of atmospheric CO2by higher plants during photo-synthesis is the primary driver of global carbon cycle.A major portion of the carbon in aquatic environments is derived from the transport of carbon produced on land.It has been estimated that worldwide about210Mt DOM and170Mt POM are transported annually to oceans from land. Carbon in the ocean is recognized as one of the three main reservoirs of organic material on the planet,equal to the carbon stored in terrestrial plants or soil humus(Hedges,1987).The terrestrially produced DOM is subject to microbial-and photodegradation and adsorption by soil and sediments.The majority of DOM in terrestrial and aquatic environments is returned to the atmosphere as CO2through microbial respiration,thereby ultimately replenishing the atmospheric CO2reserve for photosynthesis and reinvi-gorating the global carbon cycle.Dissolved organic carbon can be envisioned both as a link and bottle-neck among various ecological bined with its dynamic nature,this enables DOM to serve as a sensitive indicator of shifts in ecological processes,especially in aquatic systems.Recently,the significance of DOM in the terrestrial environment has been realized and attempts have been made to extend this knowledge to DOM dynamics in aquatic envir-onments.However,DOM dynamics on land are fundamentally different from those in water,where biomass of primary producers is relatively small, allochthonous sources of DOM are dominant,the surface area of reactive solid particles(i.e.,sediments)is smaller,and the fate of DOM is strongly influenced by photolysis and other light-mediated reactions.In contrast,the dynamics of DOM on land are largely controlled by its interactions with abiotically and biotically reactive solid components.Although there have been a number of reviews on the individual components of DOM in soils(e.g.,sources and sink—Kalbitz et al. (2000);microbial degradation—Marschner and Kalbitz(2003);sorption by soils—Kaiser et al.(1996)),there has been no comprehensive review linking the dynamics of DOM to its environmental significance.This chapter aims to elaborate on the production and degradation of DOM inDissolved Organic Matter5 soils under different landscape conditions,identify its sources and sinks,and integrate its dynamics with environmental impacts.Understanding the long-term control on DOM production and flux in soils will be particularly important in predicting the effects of various environmental changes and management practices on soil carbon dynamics.Improved knowledge on the environmental significance of DOM can enhance the development of strategies to mitigate DOM-induced environmental impacts.It is hoped that this chapter will encourage greater interaction between terrestrial and aquatic biogeochemists and ecologists and stimulate the unraveling of fundamental biogeochemical processes involved in the synthesis and trans-port of DOM in terrestrial and aquatic ecosystems.2.Sources,Pools,and Fluxes of DissolvedOrganic Matter in SoilsNearly all DOM in soils comes from photosynthesis.This represents the various C pools including recent photosynthates,such as leaf litter, throughfall and stemflow(in the case of forest ecosystems),root exudates, and decaying fine roots,as well as decomposition and metabolic by-pro-ducts and leachates of older,microbiologically processed SOM(Figure1) (Guggenberger,et al.,1994a;McDowell,2003;McDowell,et al.,1998). The majority of DOM in soils and aquifers originates from the solubilization of SOM accumulated through vegetation and the addition of biological waste materials(Guggenberger,et al.,1994b;McDowell,2003;McDowell, et al.,1998;Tate and Meyer,1983).The addition of biological waste materials,such as poultry and animal manures and sewage sludges,increases the amount of DOM in soils either by acting as a source of DOM or by enhancing the solubilization of the SOM.Most biological waste materials of plant origin contain large amounts of DOM(Table1)and the addition of certain organic manures such as poultry manure increases the pH and thereby enhances the solubilization of SOM(Schindler et al.,1992).The concentrations of DOM in soils and aquifers are highly susceptible to changes induced by humans,such as cultivation,fire,clear-cutting, wetland drainage,acidic precipitation,eutrophication,and climate change (Kreutzweiser et al.,2008;Laudon et al.,2009;Martinez-Mena et al.,2008; Mattsson et al.,2009;Yallop and Clutterbuck,2009).Dissolved organic matter in environmental samples,such as soils and manures,is often extracted with water or dilute aqueous salt solutions.Various methods have been used to measure the concentration of DOM in extracts (Table2).These methods are grouped into three categories(Moore, 1985;Sharp et al.,2004;Stewart and Wetzel,1981;Tue-Ngeun et al., 2005).The most frequently used method involves the measurement ofabsorption of light by the DOM using a spectrophotometer (Stewart and Wetzel,1981).The second method involves wet oxidation of samples containing DOM and the subsequent measurement of the CO 2released or the amount of oxidant consumed (Ciavatta et al.,1991).This method is often referred to as chemical oxygen demand (COD).Dichromates or permanganates are the most common oxidizing agents used in the wet oxidation of DOM,and the amount of oxidant consumed in the oxidation of DOM is measured either by titration with a reducing agent or by calorimetric methods.The third method involves dry oxidation of DOM to CO 2at high temperature in the presence of a stream of oxygen.The amount of CO 2produced is measured either by infrared (IR)detector or by titration after absorbing in an alkali,or by weight gain after absorbing in ascarite (Bremner and Tabatabai,1971).The most commonly used dry combustion techniques include LECO TM combustion and total organic carbon (TOC)analyzer.B horizonA horizonDOMDOMLitter layer Crop residueC horizonAquiferAgricultural soilForest soil 1111101099886677CO 2CO 2PhotosynthesisPhotosynthesis554433212Parent/geologicmaterialFigure 1Pathways of inputs and outputs of dissolved organic matter (DOM)in forest and agricultural soils.Inputs:1,throughfall and stemflow;2,root exudates;3,microbial lysis;4,humification;5,litter/and crop residue decomposition;6,organic amendments;outputs;7,microbial degradation;8,microbial assimilation;9,lateral flow;10,sorp-tion;11,leaching.6Nanthi S.Bolan et al.Plant litter and humus are the most important sources of DOM in soil,which is confirmed by both field and laboratory (including greenhouse)studies (Kalbitz et al.,2000;Kalbitz et al.,2007;Muller et al.,2009;Table 1Sources of dissolved organic matter input to soilsSourcesTotal organic matter (g C kg À1)Dissolvedorganic matterReference(g C kg À1)(%of total organic matter)Pasture leys Brome grass 13.30.0410.31Shen et al .(2008)Clover 15.10.0390.26Shen et al .(2008)Crowtoe10.40.0360.35Shen et al .(2008)Lucerne Cv.Longdong 11.40.0380.32Shen et al .(2008)Lucerne Cv.Saditi 10.90.0360.33Shen et al .(2008)Sainfoin 13.80.0400.29Shen et al .(2008)Sweet pea 10.20.0340.33Shen et al .(2008)SoilForest soil—litter leachate 60.00.0260.04Jaffrain et al.(2007)Arable soil12.00.150 1.25Gonet et al.(2008)Soil under bermuda grass turf 8.100.300 3.70Provin et al.(2008)Pasture soil 32.0 1.02 3.18Bolan et al.(1996)Pasture soil82.5 3.12 3.80Bolan et al.(1996)Organic amendments Sewage sludge 420 2.420.58Hanc et al.(2009)Sewage sludge 321 6.00 1.87Bolan et al.(1996)Paper sludge 2817.19 2.56Bolan et al.(1996)Poultry manure 4258.18 1.92Bolan et al.(1996)Poultry litter a37775.720.1Guo et al.(2009)Mushroom compost 3857.10 1.84Bolan et al.(1996)Fresh spent mushroom substrate28813346.2Marin-Benito et al.(2009)Composted spentmushroom substrate 27443.415.8Marin-Benito et al.(2009)Separated cow manure 4569.80 2.15Zmora-Nahuma et al.(2005)Poultry manure 4258.18 1.92Bolan et al.(1996)Pig manure2966.132.07Bolan et al.(1996)aBisulfate amended,phytase-diet Delmarva poultry litter.Dissolved Organic Matter 7Table2Selected references on methods of extraction and analysis of DOM in environmental samplesSamples Extraction of DOM Measurement of DOM ReferenceVolcanic ash soils Soil solutions collected by centrifugation ofcores at7200rpm;filtration(0.45m mfilters)DOC by Shimadzu TOC-5000analyzerKawahigashi et al.(2003)Peat—moorsh soil Soil samples were crushed an passed througha1mm sieve,then heated in a redistilledwater at100 C for2h under a reflexcondenser;filtration(0.45m mfilters)DOC by Shimadzu TOC5050A analyzerSzajdak et al.(2007)Soils(medial,amorphic thermic,Humic Haploxerands)Extraction with0.5mol LÀ1K2SO4solution1:5(w/v);filtration(AdvantecMFS Nº5C paper).TOC by combustion at675 Cin an analyzer(Shimadzu—model TOC-V CPN)Undurraga et al.(2009)Moss,litter and topsoil (0–5cm)Aqueous samples were estimated for DOCby oxidation of the sample with asulfochromic mixture(4.9g dmÀ3K2Cr2O7and H2SO4,1:1,w/w)withcolorimetric detection of the reduced Cr3þColorimeter KFK-3at590nm Prokushkin et al.(2006)Soil solutions from forested watersheds of North Carolina Samples werefiltered through a WhatmanG/F glassfiberfilters.Wet combustion persulfatedigestion followed byTOC analyzerQualls and Haines(1991)Organic fertilizer Extracted DOC by0.01M CaCl2solutionwith a solid to solution ratio of1:10(w/v),mixed for30min at200rpm;filtration(0.45m mfilter)Shimadzu TOC-5000ATOC analyzerLi et al.(2005)Soil solution and stream waters along a natural soil catena Soil solution collected by tension-freelysimetersDOC by infrared detectionfollowing persulfateoxidationPalmer et al.(2004)Liquid and solid sludge,farm slurry,fermented straw,soil, and drainage water Water extraction followed by centrifugation(40,000Âg)andfiltration(0.45m mfilter)Dry combustion(DhormannCarbon Analyzer DC-80)Barriuso et al.(1992)Soils,peat extract,sludge,pig and poultry manure and mushroom compost Extracted with water(1:3solid:solution ratio);centrifugation(12,000rpm)andfiltration(0.45m mfilter)Wet chemical oxidation withdichromate followed byback titrationBaskaran et al.(1996)Soil(Entic Haplothord)Extraction with deionized water(1:10solid:solution ratio);filtered through0.45m mpolysulfore membrane Dry combustion(TOCanalyzer Shimadzu5050)Kaiser et al.(1996)Pig manure Extracted with water(1:3solid:solution ratio);shaken at200rpm for16h at4o C;centrifugation(12,000rpm)andfiltration(0.45m mfilter)DOC by Shimadzu TOC-5000A TOC analyzerCheng and Wong(2006)Cow manure slurryfiltered through0.45m m polysulforemembrane TOC analyzer using UVabsorbanceAguilera et al.(2009)Sewage sludge DOC was extracted in a soil:water ratio of1:10(w/v)after1h agitation.Wet combustion withchromate followed by backtitrationGasco´and Lobo(2007)River water Natural water from riverfiltered by0.22m mfilter DOC by wet oxidation TOCanalyzerKrachler et al.(2005)Peat water Peat waterfiltered through0.45m mmembranefilters DOC was analyzed using ahigh-temperature catalyticoxidation method(Dohrman DC-190analyzer)Rixen et al.(2008)River water Filtered through0.7m m glassfiberfilter In situ optical technologyusingfluorescenceSpencer et al.(2007)(continued)Table2(continued)Samples Extraction of DOM Measurement of DOM ReferenceSea water Filtered through0.45m m polysulforemembrane High-temperaturecombustion instrument tomeasure isotopecomposition of DOCLang et al.(2007)Freshwater Filtered through0.7m m glassfiberfilter Acid-peroxydisulfatedigestion and high-temperature catalyticoxidation(HTCO)withUV detectionTue-Ngeun et al.(2005) Effluent water–In situ UV spectrophotometer Rieger et al.(2004)Groundwater,lake water, and effluent –High-performance liquidchromatography-sizeexclusion chromatography-UVAfluorescence systemHer et al.(2003)Sea water and effluent Filtered through0.7m m glassfiberfilter Measurement of carbonatomic emission intensity ininductively coupled plasmaatomic emissionspectrometry(ICP-OES)Maestre et al.(2003)Lake water Water samplesfiltered using precombustedGF/Ffilters TOC analyzer(TOC5000;Shimadzu)Ishikawa et al.(2006)Soil solution and stream water from forested catchments Samples werefiltered through0.45m mfiltersDOC by Shimadzu TOC5050A analyzerVestin et al.(2008)Dissolved Organic Matter11 Sanderman et al.,2008).In forest ecosystems,which are the most intensively studied with regard to C cycling and its associated DOM dynamics,the canopy and forest floor layers are the primary sources of DOM(Kaiser et al., 1996;Kalbitz et al.,2007;Park and Matzner,2003).However,it is still unclear whether DOM originates primarily from recently deposited litter or from relatively stable organic matter in the deeper part of the organic horizon(Kalbitz et al.,2007).In a temperate,deciduous forest,the source of DOM leaching from the forest floor(O layer)is generally a water-soluble material from freshly fallen leaf litter and throughfall(Kalbitz et al.,2007;Qualls et al.,1991).Appar-ently all of the DOM and dissolved organic N(DON)could have origi-nated from the Oi(freshly fallen litter)and Oe(partially decomposed litter) horizons.They further observed that,while about27%of the freshly shed litter C was soluble,only18.4%of the C input in litterfall was leached in solutions from the bottom of the forest floor.Virtually all the DOM leached from the forest floor appeared to have originated from the upper forest floor,with none coming from the lower forest floor—an indication of the role of this litter layer as a sink.The role of freshly deposited litter as DOM source was further corroborated by laboratory studies(Magill and Aber, 2000;Moore and Dalva,2001;Muller et al.,2009;Sanderman et al.,2008). Michalzik and Matzner(1999)found high fluxes of DOM from the Oi layer than from the Oe and Oa layers and indicated that the bottom organic layers acted instead as a sink rather than as a source of DOM.Logically,however, because of the more advanced state of decomposition,the bottom litter layers could produce more DOM than the surface layer.Indeed,Solinger et al.(2001)measured greater DOM fluxes out of the Oa than out of the Oi layer.Recently,Froberg et al.(2003)and Uselman et al.(2007)confirmed with14C data that the Oi layer is not a major source of DOM leached from the Oe layer.In a comprehensive synthesis of42case studies in temperate forests, Michalzik et al.(2001)observed that,although concentrations and fluxes differed widely among sites,the greatest concentrations of DOM(and DON)were generally observed in forest floor leachates from the A horizon and were heavily influenced by annual precipitation.However,somewhat surprisingly,there were no meaningful differences in DOM concentrations and fluxes in forest floor leachates between coniferous and hardwood sites. The flux of soluble organic compounds from throughfall and the litter layer could amount to1–19%of the total litterfall C flux and1–5%of the net primary productivity(Froberg et al.,2007;McDowell and Likens,1988; Qualls et al.,1991).Nearly one-third of the DOM leaving the bottom of the forest floor originated from throughfall and stemflow(Qualls et al.,1991; Uselman et al.,2007).Values for the potential solubility of litter in the field and in laboratory studies are in the5–25%range of the litter dry mass and 5–15%of the litter C content(Hagedorn and Machwitz,2007;McDowell12Nanthi S.Bolan et al. and Likens,1988;Muller et al.,2009;Sanderman et al.,2008;Zsolnay and Steindl,1991).In typical soils,DOM concentrations may decrease by50–90%from the surface organic layers to mineral subsoils(Cronan and Aiken,1985;Dosskey and Bertsch,1997;Worrall and Burt,2007).Similarly,fluxes of DOM in surface soil range from10to85g C mÀ2yrÀ1,decreasing to2–40g C mÀ2 yrÀ1in the subsoils(Neff and Asner,2001).In cultivated and pastoral soils,plant residues provide the major source of DOM,while in forest soils,litter and throughfall serve as the major source (Ghani et al.,2007;Laik et al.,2009).In forest soils,DOM represents a significant proportion of the total C budget.For example,Liu et al.(2002) calculated the total C budgets of Ontario’s forest ecosystems(excluding peat lands)to be12.65Pg(1015g),including1.70Pg in living biomass and10.95 Pg in DOM in soils.Koprivnjak and Moore(1992)determined DOM concentrations and fluxes in a small subarctic catchment,which is composed of an upland component with forest over mineral soils and peat land in the lower section.DOM concentrations were low(1–2mg LÀ1)in precipita-tion and increased in tree and shrub throughfall(17–150mg LÀ1),the leachate of the surface lichens and mosses(30mg LÀ1),and the soil A horizon(40mg LÀ1).Concentrations decreased in the B horizon(17mg LÀ1)and there was evidence of strong DOM adsorption by the subsoils.Khomutova et al.(2000)examined the production of organic matter in undisturbed soil monoliths of a deciduous forest,a pine plantation,and a pasture under constant temperature(20 C)and moisture.After20weeks of leaching with synthetic rain water at pH5,the cumulative values of DOM production followed:coniferous forest>deciduous forest>pasture,the difference being attributed to the nature of carbon compounds in the original residues.The residues from the coniferous forest were found to contain more labile organic components.Among ecosystems types,Zsolnay(1996)indicated that DOM tends to be greater in forest than agricultural soils:5–440mg LÀ1from the forest floor compared with0–70mg LÀ1from arable soils.Other studies have also indicated greater concentrations of DOM and concentrations in grasslands than in arable soils(Ghani et al.,2007;Gregorich et al.,2000;Haynes, 2000).In general,DOM concentration decreases in the order:forest floor> grassland A horizon>arable A horizon(Chantigny,2003).The rhizosphere is commonly associated with large C flux due to root decay and exudation(Muller et al.,2009;Uselman et al.,2007;Vogt et al., 1983).Microbial activity in the rhizosphere is enhanced by readily available organic substances that serve as an energy source for these organisms (Paterson et al.,2007;Phillips et al.,2008).Because of their turnover,soil microbial biomass is also considered as an important source of DOM in soils (Ghani et al.,2007;Steenwerth and Belina,2008;Williams and Edwards, 1993).Thus,microbial metabolites may represent a substantial proportionDissolved Organic Matter13 of the soil’s DOM.It may well be that the rate of DOM production and extent of DOM dynamics in soil is regulated by the rate of litter/residue incorporation in soils,kinetics of their decomposition,and various biotic and abiotic factors(Ghani et al.,2007;Kalbitz et al.,2000;Michalzik and Matzner,1999;Zech et al.,1996).In summary,the various C pools in an ecosystem represent the sources of DOM in soils.Due to their abundance,recently deposited litter and humus are considered the two most important sources of DOM in forest soils. Similarly,recently deposited crop residues and application of organic amendment such as biosolids and manures are the most important sources of DOM in arable soils.However,the role of root decay and/or exudates and microbial metabolites cannot be downplayed in both forested and arable ecosystems.3.Properties and Chemical Composition ofDissolved Organic Matter in Soils3.1.Structural componentsBecause DOM is a heterogeneous composite of soluble organic compounds arising from the decomposition of various carbonaceous materials of plant origin,including soluble microbial metabolites from the organic layers in the case of forest ecosystem,DOM constituents can be grouped into “labile”DOM and“recalcitrant”DOM(Marschner and Kalbitz,2003). Labile DOM consists mainly of simple carbohydrate compounds(i.e., glucose and fructose),low molecular weight(LMW)organic acids,amino sugars,and LMW proteins(Guggenberger et al.,1994b;Kaiser et al.,2001; Qualls and Haines,1992).Recalcitrant DOM consists of polysaccharides (i.e.,breakdown products of cellulose and hemicellulose)and other plant compounds,and/or microbially derived degradation products(Marschner and Kalbitz,2003)(Table3).Soil solution DOM consists of LMW carbox-ylic acids,amino acids,carbohydrates,and fulvic acids—the first comprising less than10%of total DOM in most soil solutions and the last(i.e.,fulvic acid)being typically the most abundant fractions of DOM(Strobel et al., 1999,2001;Thurman,1985;van Hees et al.,1996).Dissolved organic matter is separated into fractions based on solubility, molecular weight,and sorption chromatography.Fractionation of DOM by molecular size and sorption chromatography separate DOM according to properties(hydrophobic and hydrophilic)which regulate its interaction with organic contaminants and soil surfaces.The most common technique for the fractionation of aquatic DOM is based on its sorption to non-ionic and ion-exchange resins(Leenheer,1981).。
METHOD AND SYSTEM FOR REMOVING OXYGEN AND CARBON D
专利名称：METHOD AND SYSTEM FOR REMOVING OXYGEN AND CARBON DIOXIDE DURINGRED CELL BLOOD PROCESSING USING ANINERT CARRIER GAS AND MANIFOLDASSEMBLY发明人：Tatsuro YOSHIDA,Paul Vernucci申请号：US13432810申请日：20120328公开号：US20130259744A1公开日：20131003专利内容由知识产权出版社提供专利附图：摘要：A portable assembly for processing red blood cells RBCs including a disposable blood collection set including a blood bag, an anaerobic storage bag and an oxygenand/or oxygen and carbon dioxide depletion device disposed between the blood collection bag and anaerobic storage bag. The portable assembly further provides for a gas circulation device in fluid communication with the oxygen or oxygen and carbon dioxide depletion device. The gas circulation device includes a pressure source that is able circulate flushing gas through the depletion device as RBCs pass from the blood collection bag, through the depletion device and into the anaerobic storage bag.申请人：Tatsuro YOSHIDA,Paul Vernucci地址：West Newton MA US,Billerica MA US国籍：US,US更多信息请下载全文后查看。
土壤无机态氮包英文
土壤无机态氮包英文英文回答：Inorganic nitrogen is a major macronutrient for plants and is essential for their growth and development. The main forms of inorganic nitrogen in soil are nitrate (NO3-) and ammonium (NH4+). Nitrate is the most common form of inorganic nitrogen in well-drained soils, while ammonium is more common in poorly drained soils.The availability of inorganic nitrogen in soil is influenced by a number of factors, including:Soil pH: Nitrate is more stable in acidic soils, while ammonium is more stable in alkaline soils.Soil texture: Sandy soils have a lower capacity to hold nitrate than clay soils.Soil organic matter: Organic matter can releaseinorganic nitrogen through decomposition.Crop management practices: Fertilization, irrigation, and tillage can all affect the availability of inorganic nitrogen in soil.Inorganic nitrogen is essential for plant growth, but it can also be a source of environmental pollution. Nitrate can leach from soils into groundwater, where it can contaminate drinking water supplies. Ammonium canvolatilize from soils into the atmosphere, where it can contribute to smog formation.中文回答：土壤无机态氮是植物主要的大量营养素，对植物的生长发育至关重要。
化学需氧量 英语
化学需氧量英语Chemical Oxygen Demand (COD)The concept of Chemical Oxygen Demand (COD) is a crucial parameter in the field of environmental science and water quality management. COD is a measure of the amount of oxygen required to oxidize all the organic and inorganic matter in a water sample, both biodegradable and non-biodegradable. This measurement is essential in understanding the overall pollution load of water bodies and the subsequent treatment required to meet environmental standards.The importance of COD lies in its ability to provide a comprehensive understanding of the water's quality. Unlike the Biochemical Oxygen Demand (BOD) test, which only measures the amount of oxygen required for the biological breakdown of organic matter, COD encompasses a wider range of organic and inorganic compounds. This includes substances that are resistant to biological degradation, such as certain industrial chemicals, pesticides, and even some types of organic matter.The COD test is performed by adding a strong oxidizing agent, suchas potassium dichromate (K2Cr2O7), to a water sample. The oxidizing agent reacts with the organic and inorganic matter, converting them to carbon dioxide and water. The amount of oxygen consumed during this process is then measured and expressed as the COD value, typically in milligrams of oxygen per liter of water (mg/L).The COD test is widely used in various industries and applications, including municipal and industrial wastewater treatment, surface water quality monitoring, and groundwater assessment. In the wastewater treatment context, COD is a crucial parameter for determining the effectiveness of the treatment process and ensuring compliance with environmental regulations. By monitoring the COD levels, operators can optimize treatment strategies, ensure efficient removal of pollutants, and minimize the impact of effluent discharge on receiving water bodies.Furthermore, COD measurements are essential in the management of industrial processes, where the disposal of high-strength waste streams can have significant environmental consequences. Industries such as food processing, pulp and paper, and chemical manufacturing rely on COD analysis to assess the pollution load of their wastewater and implement appropriate treatment methods.In addition to its practical applications, COD measurement also playsa vital role in scientific research and environmental monitoring. Researchers use COD data to study the sources, transport, and fateof organic and inorganic pollutants in aquatic ecosystems, as well as to assess the overall health and resilience of these systems. This information is crucial for the development of effective environmental policies, conservation strategies, and sustainable resource management practices.Despite its widespread use, the COD test is not without its challenges. The method can be influenced by the presence of certain inorganic compounds, such as chlorides and nitrites, which can interfere with the oxidation process. Additionally, the COD test does not provide information on the specific nature of the organic compounds present, which can limit its usefulness in certain applications.To address these challenges, researchers and practitioners have developed various modifications and alternative methods for COD determination, such as the use of specific oxidizing agents, microbial-based assays, and advanced analytical techniques like gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS).In conclusion, the Chemical Oxygen Demand (COD) is a fundamental parameter in the field of water quality assessment and environmental management. It provides a comprehensive understanding of thepollution load in water bodies, enabling informed decision-making and the implementation of effective treatment strategies. As environmental concerns continue to be a global priority, the importance of COD monitoring and analysis will only increase, contributing to the sustainability and protection of our precious water resources.。
dioxido 氧 基
dioxido 氧基二氧化氮（dinitrogen dioxide），简称二氧化氮，化学式为NO2。
二氧化氮是一种红棕色的气体，具有刺激性气味。
它是由一分子氮气与两分子氧气反应而成的。
二氧化氮是一种重要的环境污染物，对人体健康和大气环境均有一定的危害。
二氧化氮的主要来源是燃烧过程中的氮氧化物排放。
工业生产、汽车尾气以及能源消耗等都是二氧化氮的重要排放源。
二氧化氮可以在大气中被光解为一氧化氮和氧气，从而参与到大气氧化反应中。
它还可以与大气中的颗粒物结合形成臭氧和酸雨，对环境造成严重的污染和破坏。
二氧化氮的存在对人体健康也有一定的影响。
长期暴露在高浓度的二氧化氮中会引起呼吸系统疾病，如哮喘、慢性支气管炎等。
此外，二氧化氮还会对眼睛、呼吸道和皮肤产生刺激，引起眼结膜炎、咳嗽、喉咙痛等症状。
因此，减少二氧化氮的排放对于保护环境和人类健康非常重要。
为了减少二氧化氮的排放，各国采取了一系列的措施。
例如，加强工业、交通和能源行业的监管，推广清洁能源和低碳技术，提高排放标准等。
此外，人们还可以通过合理规划交通、减少车辆行驶里程、推广公共交通工具等方式来减少汽车尾气的排放。
这些措施的实施可以有效地降低二氧化氮的排放量，改善大气环境质量。
个人也可以在日常生活中采取一些措施来减少二氧化氮的产生。
例如，选择环保的家电产品，合理使用能源，减少能源消耗；定期清洁空调、加强室内通风，减少室内空气污染；尽量减少烧烤、烟熏等高温烹饪方式，避免产生过多的二氧化氮等。
这些小小的改变都可以为减少二氧化氮的排放做出贡献。
二氧化氮作为一种环境污染物，对大气环境和人体健康都有一定的危害。
为了保护环境和人类健康，我们应该采取各种措施来减少二氧化氮的排放。
只有共同努力，才能创造一个更清洁、更健康的环境。
纳米金催化剂可能替代有机合成中的有毒物
纳米金催化剂可能替代有机合成中的有毒物2016-10-13 13:21来源：内江洛伯尔材料科技有限公司作者：研发部在有机产品的生产过程中，有一步是必需的，即将氧原子与含碳化合物结合的氧化反应过程。
理论上讲，这种反应可以清洁地进行——使用来自空气中的氧气，但前提必须将两个结合在一起的氧原子的化学键打断，便于氧原子游离进行反应。
来自英国加的夫大学的化学家格雷姆·哈钦斯解释说：在过去，大多数氧化反应依赖于气味刺鼻的氧化剂(如过乙酸等)，它会产生有毒的废弃(副)产物。
现在，哈钦斯研究小组发现，直径25纳米的黄金粒子在相对较低温度和与汽车轮胎相近的气压环境下，可以激活空气中的氧气。
被激活的氧气很容易与碳分子结合。
在许多化学反应中，不同的溶剂被用来帮助溶解反应物并促进原子间的结合；但是被黄金粒子激活的氧气，可以完成结合反应而无需这些溶剂。
哈钦斯指出：摆脱这些溶剂的使用是工业界与环境友好的最佳方法之一，它减少了那些有可能污染环境的液体的数量。
“如果你生产出产品而不使用这些溶剂，那可是从根本上解决了环保问题。
”在推进黄金催化剂项目的应用上，目前，哈钦斯研究组与设在伦敦的化工企业——梅西公司正在积极的合作中。
黄金正常情况下是惰性的，那就是为什么它非常稳定并且被加工成许多名贵饰品的原因。
哈钦斯说：“如果你改变黄金的结构使之成为数百个原子组成的分子簇，它就会变得令人难以置信的活跃。
”应用在催化剂中，黄金粒子易与比其大的含碳颗粒的结合。
哈钦斯认为：两者之间的界面正是氧化反应发生的地方。
研究小组使用金属铋来调节金催化剂的活性，即封锁金催化剂表面的特定位点进行调节。
研究中还发现，金催化剂有利于环氧化物的产生。
哈钦斯说：“环氧化物是一类贵重的化学物品．但其不容易制备。
”目前的最清洁的反应方法依赖于过氧化氢(被普遍用作一种防腐剂)。
尽管这是相对清洁的，哈钦斯估计：作为一种氧源，过氧化氢的使用比空气昂贵8倍。
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Abstract The s o u r c e s , mechanisms, and e x p e c t e d l e v e l s of oxygen and n i t r o g e n contamination during gas tungsten a r c , gas metal a r c , shielded metal a r c , s e l f - s h i e l d e d m e t a l a r c , and submerged a r c w e l d i n g are reviewed. Calcul a t i o n s i n d i c a t i n g t h e i m p o r t a n c e of decomposition of SiO2 i n t o s i l i c o n monoxide and oxygen a r e p r e s e n t e d , i n d i c a t i n g t h a t s i l i c o n t r a n s f e r between t h e s l a g and m e t a l o c c u r s by a g a s - m e t a l r a t h e r t h a n a s l a g - m e t a l r e a c t i o n mechanism. A model s u g g e s t i n g t h a t a r c s t a b i l i z i n g a d d i t i o n s t o f l u x e s s h o u l d p r o v i d e v o l a t i l e s u b s p e c i e s upon h e a t i n g i s a l s o d i s c u s s e d . Introduction Oxygen and n i t r o g e n c o n t a m i n a t i o n o f weld m e t a l i s of c o n c e r n i n t h a t r e l a t i v e l y s m a l l q u a n t i t i e s o f t h e s e e l e m e n t s may a f f e c t t h e c l e a n l i n e s s , toughness a n d / o r p o r o s i t y of t h e r e s u l t i n g weldment. G e n e r a l l y s p e a k i n g , t h e s e e l e m e n t s s h o u l d b e m a i n t a i n e d a t a s low a l e v e l a s p o s s i b l e ; e x c e p t p e r h a p s i n t h e c a s e o f a u s t e n i t i c s t a i n l e s s s t e e l s , where t h e p e r c e n t am a n i p u l a t e d b y changing t h e n i t r o g e n c o n t e n t of the weld m e t a l . I n any case, t h e s o u r c e s and mechanisms which c o n t r o l t h e oxygen and n i t r o g e n c o n t e n t s d u r i n g w e l d i n g must b e u n d e r s t o o d i n o r d e r t o p r o v i d e c o n t r o l o v e r t h e p r o c e s s and t h e r e s u l t a n t p r o p e r t i e s o f t h e weldmen t Providing t h a t high q u a l i t y s t a r t i n g m a t e r i a l s a r e used, t h e r e a r e b a s i c a l l y o n l y two s o u r c e s of oxygen and n i t r o g e n c o n t a m i n a t i o n of t h e weld m e t a l ; v i z . , a b s o r p t i o n from t h e s u r r o u n d i n g atmosphere and r e a c t i o n w i t h any f l u x which may b e p r e s e n t . A b s o r p t i o n from t h e atmosphere depends largely on plasma j e t phenomena;flow r a t e , c o m p o s i t i o n , a n d i o n i z a t i o n s t a t e o f t h e s h i e l d i n g g a s ; and t h e a b s o r p t i o n mechanisms a t t h e m o l t e n metal-gas I n t e r f a c e . F l u x e s m a y c o n t r i b u t e oxygen by d e c o m p o s i t i o n of l e s s s t a b l e o x i d e s , w h i l e n i t r o g e n c o n t a m i n a t i o n from t h e f l u x , which i s of p o t e n t i a l c o n c e r n , i s n o t g e n e r a l l y i m p o r t a n t . The p u r p o s e of t h e p r e s e n t p a p e r i s t o d i s c u s s t h e s e s o u r c e s and t h e i r r e l a t i v e i m p o r t a n c e i n t h e v a r i o u s a r c welding processes.
Proc. Proc. of o f Weldments:Physical Weldments:PhysicalMetallurgy Metallurgy and and Failure Failure Phenomena; Phenomena;Bolton Bolton Landing, Landing, Lake Lake George; George; N.Y ;; 27-30 2 7 : 3 0 Aug. Aug. 1978, 1978,R.J. R.J. Cristoffel, Cristoffel, ed., ed., General General Electric, Electric, Schenectady, Schenectady, NY, 31-42, 31-42,1979. 1979.
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Arc Phenomena
Rein h a s d e s c r i b e d t h e oxygen and n i t r o g e n l e v e l s t o be e x p e c t e d when H i s summary , r e p r o d u c e d using s e v e r a l d i f f e r e n t a r c welding processes. i n F i g u r e 1, i l l u s t r a t e s t h e wide v a r i a t i o n s i n n i t r o g e n and oxygen l e v e l s which may b e found among a r c w e l d i n g p r o c e s s e s g e n e r a l l y , and w i t h i n the individual processes specifically. I n o r d e r t o understand t h e s e d i f f c r e n c e s , i t i s n e c e s s a r y to d i s t i n g u i s h t h e b a s i c d i f f e r e n c e s between t h e F i r s t , however, s e v e r a l fundamental a s p e c t s of a r c w e l d i n g processes. s h o u l d be reviewed. Welding a r c s c o n s i s t of i o n i z e d g a s e s c o n d u c t i n g l a r g e e l e c t r i c a l c u r r e n t s . The a r c m a i n t a i n s a d e l i c a t e b a l a n c e between t h e h e a t g e n e r a t e d by t h e e l e c t r i c a l r e s i s t a n c e of t h e plasma