闽南民间草药风柜斗草研究进展

目的:风柜斗草在福建省民间作为一种治疗肝炎、保肝护肝的单验方被广为使用,是一种极有价值的中草药。为进一步对其研究开发提供参考依据。方法:本文对风柜斗草的生药学研究、化学成分及提取方法、含量测定、药理作用等方面的研究进展进行综述。     

硫酸蒽酮法测定风柜斗草粗多糖含量

通过水提醇沉法提取风柜斗草粗多糖成分,对提取的条件进行优化处理,采用可见–紫外分光光度法进行分析测定,建立风柜斗草多糖含量的硫酸–蒽酮显色测定方法。结果显示,样品平均加标回收率为98.30%,相对标准偏差RSD为1.28%(n=9),三批样品测得的多糖平均含量分别为16.01mg/g、15.46mg/g、16.21mg/g。该方法准确、可靠,可用于风柜斗草粗多糖含量测定。     

高效液相色谱法测定风柜斗草中槲皮素和异鼠李素的含量

目的：建立闽南草药风柜斗草中槲皮素和异鼠李素含量测定的方法。方法：采用70%甲醇超声提取,HPLC-PDA分析方法测定。色谱条件为色谱柱Ultimate Column TMC18 4.6×150mm×5μm,流动相甲醇∶0.5%磷酸=55∶45,流速：1.0 mL/min,柱温：30℃,检测波长：370nm。结果：闽南...     

蒙古山萝卜花化学成分的预试验

目的:通过预试验,初步探索蒙古山萝卜花的化学成分.方法;采用试管法和滤纸法,对蒙古山萝卜花的75%乙醇、95%乙醇及水提取物进行研究,通过多种指示剂和显色剂的沉淀反应或颜色反应,初步推断蒙古山萝卜花中可能古有的化学成分结果与结论:蒙古山萝h花中可能含有三萜皂甙、鞣质或酚类、有机酸、黄酮、生物碱、还原糖及蛋白质等化学成分.     

胶囊式储油柜假油位故障原因分析及对策

通过对近年来胶囊式储油柜的假油位故障实例进行分析，对引起胶囊式储油柜假油位典型故障产生的原因、对策及处理方法进行总结介绍。     

基于SAMMIE的智能快递柜人机分析及改良设计

智能快递柜的普及给人们生活带来极大的便捷,由于该类产品出现时间短及迭代缓慢,在产品的人机工程性能方面存在一些问题。本文以丰巢智能快递柜为例,首先通过发放网络问卷、实地观察和用户访谈方法,对用户使用丰巢智能快递柜存在的问题进行了调研与分析;然后使用人机分析软件SAMMIE建立使用智能快递柜的数字化场景,并开展多个百分位数字化人仿真操作行为分析,仿真结果发现该丰巢智能快递柜在尺寸和布局等方面存在问题;最后对该快递柜进行了改良设计并再次进行了分析,验证了本文提出的改善智能快递柜人机工程性能的分析方法和流程的可行性。     

深圳市商场空调系统能耗与节能策略分析

通过对深圳市大量商场空调运行状况的调研,测试得到各空调系统实际的单位面积能耗,并对其能耗差异进行了分析。对特定商场的实际运行能耗进行年度内的数据采集,得到了不同月份水泵、风柜、主机、冷却塔等设备的能耗比例。通过对各设备的能耗水平以及设备和系统的节能潜力的分析和测试,得到了节能改造的策略和手段,为商场类空调系统节能改造提供了基础依据,并提出了系统节能的方法。     

某锅炉水冷壁腐蚀原因分析及其改进措施

针对某电厂锅炉水冷壁管的严重腐蚀问题,通过宏观形貌检查、化学成分分析、微观组织分析及能谱分析等方法进行了系统分析。结果表明:该锅炉燃用高硫煤时,炉膛火焰中心偏斜导致水冷壁局部出现还原性气氛,产生硫化物型高温腐蚀。最后针对具体原因,提出了控制燃煤质量、调整燃烧、增加贴壁风等改进措施,有效地解决了该锅炉水冷壁高温腐蚀问题。     

某洁净室的检测与节能分析

本文通过对某洁净室温度场及洁净度在不同的送风量下的检测分析，得出了在全面地板回风的气流组织下，运行管理千级的洁净室时，可适当调低送风量以减小运行耗能，同时指出了采用洁净室内壁面温度作为控制参数来控制空调风柜运行会导致温度场控制不精确，室温波动较大，建议采用引入工作位室温参数来控制空调风柜运行，以减少运行能耗，防止室温波动过大。     

乙二醇载冷剂对制冷设备换热器铜管腐蚀分析

为了改善乙二醇载冷剂对制冷设备换热器铜管腐蚀问题,确认腐蚀机理并制定改善措施.通过对铜管腐蚀泄漏点进行宏、微观检查、化学成分分析及扫描电子显微镜检查等方法进行分析讨论.确认铜管腐蚀最主要的原因是制冷系统中的碳钢材料与酸化的乙二醇溶液反应,产生铁离子与换热器的铜管发生电化学反应,导致腐蚀穿孔泄漏.通过对制冷系统的乙二醇腐...     

Oxidative properties and chemical stability of fluoronanotubes in matrixes of binary inorganic compounds

The chemical stability of fluoronanotubes in selected solid inorganic matrixes has been studied by initially mixing and mechanically grinding the components and subsequently heating them at temperatures ranging from 35 to 600 degrees C. The inorganic compounds selected for matrixes included halides (KBr, KI, Lil, LiBr, LiCl, NaCl, Znl2), oxides (Li2O, Fe2O3, PbO, MnO), lithium peroxide (Li2O2), potassium superoxide (KO2), sulfides (Li2S and ZnS), zinc selenide (ZnSe), lithium nitride (Li3N), and aluminum phosphide (AIP). Solid products, resulting from the proceeding chemical reactions, were analyzed by X-ray diffraction, Raman spectroscopy, and SEM/EDX elemental analysis. Gaseous and volatile products were identified with the help of the TGA/MS technique. Experimental data presented in this paper provide clear evidence that fluoronanotubes are not chemically inert toward the solid matrixes studied and exhibit significant oxidative properties in the redox reactions occurring under various temperatures, depending on the nature of the inorganic compound.     

Fate of ammonia in the atmosphere--a review for applicability to hazardous releases

The physical and chemical mechanisms responsible for the removal of ammonia from the atmosphere have been reviewed. Capture by atmospheric moisture (clouds, rain, fog), surface water (rivers, lakes, seas), and deposition on vegetation and soil constitute the main pathways for ammonia removal from the troposphere. Ammonia catalyzes the atmospheric oxidation of sulfur dioxide to sulfur trioxide and reacts rapidly with acidic components of the atmosphere (sulfuric, nitric, and hydrochloric acids). The ammonium salts formed are the main components of smog aerosols and thus affect the opacity of the atmosphere and the earth radiation budget. Slow oxidation of ammonia in the atmosphere plays only a minor role in its removal. The data obtained for ammonia reactions under normal atmospheric conditions are generally applicable to model chemical reactions occurring during massive release of ammonia in the atmosphere, provided the impact of high ammonia concentration on the mass transfer processes that control some of these reactions, are taken into account.     

Thin-Shell Structure of Nanometal Particles

As is well known, the rare-earth and transition-metal elements are the main active components in catalysis because of their special d and f electron structures. In our laboratory, a type of nanometer particle of a transition metal with a rare-earth outer shell was synthesized by a hydrogen arc plasma method, and their microstructures were analyzed by TEM and an X-ray diffraction profile refinement method. The nanoparticles were used as a catalyst in some chemical reactions. The catalytic activities of the nanometer particles with and without a rare-earth thin shell were evaluated by means of the catalytic reactions of toluene, nitrobenzene hydrogenation, and carbon monoxide oxidation. The results of these chemical reactions demonstrated that the nanometer transition metal particles with a rare-earth outer shell possess much higher catalytic activity and selectivity than those particles without a rare-earth outer shell. This means that the rare-earth shell plays an important role in these chemical reactions. This catalytic mechanism of the rare-earth shell is discussed.     

Some lessons from thermal-runaway incidents

An analysis is presented of 142 industrial incidents in batch reactors involving thermal-runaway chemical reactions of the type A + B → products (incidents involving thermal stability problems with single components are not included) occurring in the UK during the period 1962–1984 and brought to the attention of the Health and Safety Executive. The purpose was to seek for any apparent trends with a view to drawing general lessons from previous mistakes. The underlying problems which led to overheating and eventual runaway have been classified under the headings process chemistry and plant design and operation; a number of contributing factors have been identified under each. Injuries are briefly discussed.     

等离子体电弧法制备的带状纳米锌的表征

约束弧等离子体电弧法用等离子体高温热源激发高能粒子的化学反应,并与骤冷技术结合构成一个制备金属纳米粉体或化合物纳米粉末材料的等离子体过程,能极好地制备高溶点(例:Ni,Fe,C等)或低溶点(例:Al,Zn等)的纳米粉末,是当前极具工业化生产应用前景的方法之一。用约束弧等离子体电弧法制备了纳米Zn粉末,用XRD,TEM,TG,DTA技术研究了纳米Zn粉末的结构、晶粒大小、晶粒形貌和热稳定性。结果表明,该粉体平均粒径小于42 nm,晶粒形貌为带状,热稳定性好。此外该粉体具有高比表面积,可用作化学反应的催化剂。     

FTIR analysis of UV aging on bitumen and its fractions

The ultraviolet (UV) aging of bitumen involves a series of complex chemical reactions due to its complicated chemistry and structure. To conduct the UV aging on simplified components of bitumen is very helpful to reveal the UV aging mechanism accurately. In this study, two bitumens were separated into four generic fractions (saturates, aromatics, resins and asphaltenes) respectively by solubility procedures and chromatographic techniques. Both bitumens and their fractions were processed to form a thin film and then aged under UV irradiation for a certain time. The Fourier transform infrared spectra of bitumens and their fractions before and after the UV aging were recorded and quantitatively analyzed based on four structural indexes to evaluate the effect of UV aging on chemical evolution of bitumens and fractions. The results show that the bitumens and their generic fractions all suffer from reactions of oxidation and aromatization during the UV aging. The single fraction separated from the bitumen suffers from more severe oxidation and is more vulnerable to the UV aging than the bitumen itself. Among the four generic fractions, saturates are the most unstable components to be oxidized by the UV aging.     

丙烯热解炭过程的气相产物分析和动力学研究(英文)

以丙烯为碳源,在700℃～1200℃进行化学气相沉积热解炭。采用气相色谱和质谱联用对反应过程中的气体产物进行定性和半定量分析,采用磁悬浮天平实时称量反应过程中的固相产物进行动力学研究,在此基础上提出丙烯分解形成热解炭的机理。气相产物的分析结果表明:丙烯热解过程产生30多种芳香化合物,随着温度的升高,主要反应生成物由萘转变为苯;动力学研究结果表明,800℃～1000℃的活化能为137±25kJ/mol,生成乙炔的基元反应控制固相产物的形成。当温度高于1000℃时,沉积行为由气相分子通过边界向固相表面扩散和气相成核共同控制,形成热解炭的主要物质逐渐由苯转变为不饱和碳氢化合物如乙烃,乙烯等。     

新型包装材料“瓦中瓦”缓冲特性研究

增强夹心瓦楞纸板("瓦中瓦")是一种新型包装材料.对6种"瓦中瓦"进行了静态压缩试验,分析其静态缓冲特性,并用性能最好的一种"瓦中瓦"与聚苯乙烯泡沫塑料对电脑主机作缓冲包装,进行振动冲击的对比试验,探索其代替聚苯乙烯泡沫塑料的可能性.结果表明,"瓦中瓦"是大型家用电器、机电设备等较为理想的环保包装材料和包装容器.     

Mechanochemically activated aluminium: Preparation, structure, and chemical properties

Mechanical treatment of aluminium with 10-30 wt% graphite in the high-energy vibration mills leads to the formation of a chemically active substance. The structure of active aluminium and its formation are investigated by X-ray diffraction, adsorption, chemical analysis, and DSC. The reactivity of active Al is checked in reactions with graphite, as well as water, oxygen, and nitrogen. At the initial stage of mechanochemical interaction of aluminium with graphite, the dispergation of components and accumulation of defects in Al and C take place. Simultaneously, the surfaces of aluminium nanoparticles are covered with the carbon layer. Then the chemical interaction of aluminium with carbon starts on the surface of particles. At the final stage, aluminium carbide is formed in the volume of particles. The maximal reactivity of Al corresponds to the Al/C nanocomposites, in which chemical interaction of components is not yet realized. The reactivity of mechanochemically activated aluminium significantly exceeds that of standard aluminium powders. Interaction of activated Al with carbon takes place at 450°C, which is 800°C lower than the temperature at which the nonactivated aluminium reacts with carbon. Two types of reactions (“isothermal” and explosive) are observed for mechanochemically activated Al with water and air.