关于状态性质的加和性

本文提出将状态性质的加和性分为三种:部分加和性、组分加和性和基因加和性。这样分类后,容量性质和强度性质的区别与联系更加清晰。凡容量性质必定具有部分加和性,而强度性质必定没有部分加和性。因此,用有无部分加和性来区分状态性质为容量性质和强度性质是最确切的,不易引起误解。部分加和性就是通常说“容量性质在一定条件下有加和性”的那种加和性。     

北京宏剑讯科软件技术有限公司--国内首家化学软件专卖店

Gaussian 03 是做半经验计算和从头计算使用最广泛的量子化学软件。可以研究：分子能量和结构、过渡态的能量和结构、化学键以及反应能量、分子轨道、偶极矩和多极矩、原子电荷和电势、振动频率、红外和拉曼光谱、NMR、极化率和超极化率、热力学性质、反应路径。计算可以模拟在气相和溶液中的体系,模拟基态和激发态;计算周期边界体系。是研究诸如取代效应、反应机理、势能面和激发态能量的有力工具。     

3种化学键离解能的区别和联系

描述化学键离解时的能量变化，有3个相应于不同反应条件的物理量：De ,Do和D298。目前化学教材仅论述了De和Do的区别和联系，遗漏了De ,Do和D298。的区别和联系。De和Do相应于0K条件下的数值，但实际化学过程都不对应0K。热力学标准温度是298．15K，因此D298。的概念远比De和Do更有实用价值。化学键离解能数据库已提供约2万个双原子和多原子物种（分子、离子、自由基、络合物等）内的D298。测量数据。建议：在新版的有关教材中，应当阐明De ,Do和D298的区别和联系。     

推荐一个大学有机化学实验:1-苯基三氮烯的合成

介绍了一个适合化学和化工专业开设的大学有机化学实验。首先苯胺在亚硝酸钠和浓盐酸的作用下发生重氮化反应生成苯基重氮盐,继而与四氢吡咯偶联得到1-苯基三氮烯。实验涉及低温反应、重结晶和熔点测定等实验操作技术以及红外光谱和核磁共振等化合物结构鉴定方法。其反应机理包括重氮化和偶联反应。该实验具有原料价廉、收率高、反应时间短和操作简便等特点,有利于培养和提高学生的实践能力和创新能力。     

微波消解原子荧光光谱法测定生物样品中砷汞

采用微波消解样品预处理技术和原子荧光光谱法,测定了生物样品中砷和汞的含量。确定了微波消解样品的条件,优化了仪器的最佳工作参数。砷和汞的含量分别在0~20μg.L-1和0~16μg.L-1范围内线性良好。砷和汞的回收率分别为100.5%和98.6%。砷和汞的检出限分别为0.21和0.06μg.L-1。试验表明,该法快速简便、准确灵敏,应用于生物样品中砷、汞的测定,结果满意。     

基于互动和合作学习的无机化学教学模式

在分析无机化学课堂教学现状和采纳学生建议的基础上提出了构建互动和合作学习的无机化学教学模式。着重介绍了"分组互动、读书报告会、尝试讲课和评判纠错"互动和合作学习的过程。教学实践表明,这种互动和合作学习正是学生需要和喜欢的无机化学教学模式。     

微波消解-原子吸收光谱法测定槐花和大黄中微量元素

采用微波消解-火焰原子吸收光谱法和石墨炉原子吸收光谱法测定了中药槐花和大黄中铜、铁、锌、镉、铬和铅。研究了槐花和大黄的微波消解试剂和消解条件。在原子吸收光谱测定的最佳条件下测定槐花和大黄中铜、铁、锌、镉、铬和铅。方法的回收率在89．2％～112．0％之间。     

人工促使烟草和菠菜胚性细胞间染色质穿壁实现植株再生——一项新的细胞工程技术(L.B技术)

本文采用了一项新的细胞工程技术。它包括亲本胚性细胞团的诱导、分离和纯化;不同亲本胚性细胞的离散、组合、离心增殖培养和细胞间重建联系和联结;活性K~+溶液处理、强化离心穿壁培养促使不同亲本细胞间染色质和细胞质广泛穿壁转移;选择培养系统的建立和再生植株等操作程序。采用这项技术成功地实现了烟草和菠菜胚性细胞间染色质和细胞质的穿壁转移,并再生了植株。遗传学和细胞学研究表明,再生植株具双亲的遗传性状和染色体。这项技术的建立可能发展成为一项新的细胞工程技术,将在理论和实践上给我们带来新的希望和设想。     

原子荧光法测定食品中砷和硒

采用氢化物发生-原子荧光光度法测定食品中砷和硒。砷和硒的相对标准偏差分别为1．17％和1．19％,检出限分别为0．28和0．40ng·ml-1。线性范围为0～100ng·ml-1,砷和硒的相关系数分别为0．9998和0．9999。砷和硒的回收率分别为95．8％～105．4％和98．5％～103．5％。     

铜基催化剂催化合成气一步合成甲醇和甲酸甲酯 I.温度和压力的影响(英文)

考察了在低温、低压和浆态反应条件下,由合成气一步直接合成甲醇和甲酸甲酯（ＭＦ）的反应和催化剂。结果表明,不同方法制各的Ｃｕ基催化剂具有不同的催化活性和甲酸甲酯选择性。采用络合沉淀法（ＣＰ）制备的催化剂具有较高的催化活性和ＭＦ选择性。温度和压力对催化剂的活性和ＭＦ选择性具有明显的影响。Ｃｕ－Ｃｒ催化剂的活性随温度和压力的增加而增加,其选择性随温度的升高而降低,随压力的升高而增加。     

聚苯胺薄膜电极上示差脉冲伏安法可逆波理论研究

本文提出了聚苯胺(PANI)薄膜电极上示差脉冲伏安法可逆波理论,经验证理论和实验结果相符合.     

Spectrophotometric and gravimetric determination of sulfur in sebacate-base lubricants

Sulfur is determined in sebacate-base lubricants spectrophotometrically and gravimetrically. In the spectrophotometric method, a 0.2–0.3-g sample is treated with mixed acids, magnesium chloride is added, and the solution is evaporated to dryness. The sulfate is reduced to hydrogen sulfide by treatment with a mixture of hydriodic. hypophosphorous, and hydrochloric acids, and the hydrogen sulfide is distilled into ammonia solution. Lead citrate reagent is added and the brownish yellow color of lead sulfide sol is measured. An improved technique and apparatus for the distillation is described. In the gravimetric method, a 5-g sample is treated with mixed acids, antimony and tin are volatilized by treatment with hydrobromic acid, and sulfur is precipitated as barium sulfate. The recommended range of the spectrophotometric method is 0.005–0.15%,and that of the gravimetric method is 0.01–1% sulfur.     

水性聚氨酯的制备及其性能的研究

本文以琥珀酸酐与三羟甲基丙烷反应,制得了含有羟基和羧基的酯类亲水性单体,并以此单体与ＴＤＩ和ＰＰＧ－１０００反应,制得了含有羧基的聚氨酯预聚体,在三乙醇胺水溶液中分散得到了水性聚氨酯（简称ＷＰＵ）。本文对预聚体的溶剂种类和用量,对乳胶粒的大小及形状的影响进行了研究,确认溶剂的用量越大,乳胶的粒径就越小;以丙酮作溶剂,乳胶粒为棒状或橄榄球状,而以丁酮为溶剂,得到的乳胶粒为圆球状。通过改变亲水单体的用     

用计算全息法检测卡塞格林系统主镜

为实现对卡塞格林光学系统中的非球面主镜表面面形的高精度检测,设计了一种二元位相型计算全息图(CGH)。介绍了工作原理,对CGH的相位模型参数的优化设计、衍射次级分离以及台阶位置与深度计算等关键问题进行了讨论。通过引入虚拟玻璃的概念快速建立非球面检测模型,针对卡塞格林系统主镜中心开孔的特点,通过加入同轴载波实现了衍射次级的完全分离,相比目前常用的倾斜载波方法简化了相位量化复杂度,数值仿真计算出了最优的台阶深度,降低了加工难度。给出了相应的设计方法及实例,研制投产了CGH。测试得到主镜面形的均方根误差为0.018λ,并与传统补偿器结果(RMS=0.019λ)进行对比,两者测试结果吻合,验证了该设计与检测方法的正确性,该设计方法简单快捷,适用于卡塞格林光学系统主镜面形检测。     

N,O-羧甲基壳聚糖的合成和性质研究

采用多段升温法将壳聚糖改性,合成了取代度为1.84、平均分子量为3.08×105、等电点为7.28的N,O-羧甲基壳聚糖(CMC),分别用紫外光谱、红外光谱、荧光光谱对其结构进行了表征,并对其水溶液的Zeta电位、电导率、表面张力以及水分散体系中羧甲基壳聚糖微粒的粒径分布进行了研究.结果表明, N,O-羧甲基壳聚糖具有表面活性;介质的pH值和浓度对羧甲基壳聚糖溶液的稳定性有很大的影响.     

Determination of free, total, and esterified cholesterol by high-performance liquid chromatography

A method is described for measuring free, total, and esterified cholesterol in blood serum in which reversed-phase liquid chromatography is used and the eluate is monitored at 200 nm. The sample for total cholesterol is prepared according to the Abell-Kendall procedure, and for free cholesterol an extract of serum--isopropanol (1:5, v/v) is used. The column is a muBondapak C18, 10 micrometers, and the mobile phase for total cholesterol is isopropanol--acetonitrile (50:50, v/v); for free cholesterol, it is isopropanol--acetonitrile--water (60:30:10). An approximation of the free cholesterol, triglycerides, and individual cholesteryl esters is obtained from single chromatograms of isopropanol extracts of serum if the first mobile phase is used. In a comparison study with the Abell-Kendall method for total cholesterol, the correlation is excellent and the precision is acceptable.     

Wastewater treatment using nanomaterial quaternary photocatalyst ZrCdPbO4 - Removal of colour pollutant by an eco friendly process

Pollution of environment is a major issue and has drawn attention of researchers throughout the globe. Water is polluted by various means like excretion of various industries and house releases, for example release of yarn, paper, and cloth industries etc. Present investigation consists of removal of such a pollutant. For this, synthesis of a novel quaternary nano particle sized photocatalyst ZrCdPbO₄ is carried and its characterization by different analytical techniques is also carried out. This is further used for removal of colour pollutants from the environment and Erythrosine-B is considered as a role model. Effect of various operational parameters like pH, concentration of dye, amount of photocatalyst, irradiation power etc. is studied, maximum degradation condition is extracted, and it is observed that reaction follows pseudo first order kinetics. Scavenger study suggests the participation of OH free radical in the reaction. Complete degradation of the dye in presence of light and photocatalyst is reported here by. Reusability of the photocatalyst is tested and is found to work up to five cycles efficiently.     

山东省主栽果树生殖器官中稀土与微量营养元素的相关性研究

通过对山东省5大类主栽果树20余个树种的花粉、种子和果实稀土与微量元素自然含量进行分析比较, 认为稀土(RE)与微量元素在各树种花粉中平均含量顺序为Fe＞Zn＞B＞Cu＞Mn＞RE, 种子中B＞Fe＞Zn＞Mn＞Cu＞RE, 果实中Fe＞B＞Zn＞Cu＞Mn＞RE. 各元素在各生殖器官中的自然分布因树种而有很大差异. 但基本规律类同, 即花粉＞种子＞果实. 花粉富集各种微量营养元素的能力都很强. 花粉和果实稀土与微量元素之间绝大多数呈正相关, 种子大多呈负相关, 但相关性均不显著.     

Spectrophotometric determination of pentaerythritol tetranitrate (PETN) in waste water from lead styphnate primer plants

An accurate spectrophotometric method is proposed for the determination of pentaerythritol tetranitrate (PETN) in waste water from lead styphnate primer plants by use of phenoldisulphonic acid. The waste water is filtered through a sintered glass crucible and the PETN is determined in the filtrate and the residue. In the determination of PETN in the filtrate, sodium hydroxide is added and the PETN is extracted with methylene chloride (in alkaline solution, styphnate and TNT are not extracted). The methylene chloride solution is then evaporated to dryness, the residue is treated with a solution of phenoldisulphonic acid in sulphuric acid, water and ammonia are added, and the yellow colour is measured. In the determination of PETN in the residue, the PETN is dissolved in acetone, an aliquot of the acetone solution is treated with water and sodium hydroxide, the PETN is extracted with methylene chloride and the colour is developed as above. Various factors affecting the determination were investigated. The solubility of PETN in water was studied.     

A Study on Alkyl Polyglycosides of the Starch

The alkyl polyglycosides (APG) is new type the surfactants that is made by regenerationresource of the starch and the grease, since the nineties of 20th century it is energetically exploited ininternational extent. APG not only good in surface activity, but also plenty on bubble, thin greasyand stabilization, there are good decontamination, compatibility, innocuity, not incitation and uniquefunction that organism decomposition of swiftness and downrightness, and so on.APG is to get production that loses one molecule water with half condensation aldehyde hydroxyand sebum alcohol hydroxy under acid catalysis. The production not is one simplicity compound, butis one of sugar polymerization degree, so it is mixture of the alkyl single glucoside, the alkyl twoglucoside and the alkyl three glucoside.Author synthesizes the surfactants of the alkyl polyglycosides, with the oleaster and potato starchand sebum alcohol, that was chosen to use duality system activator of plant acid and p-toluene-sulfoacid for the first time. The adoption way is that the lower alkyl polyglycosides is firstly formed byreaction of lower alcohol with starch then exchanged with high alcohol to obtain APG. The study isto make certain most technics condition, determining capillary tension and the pastern sheafdeepness of critical, calculating HLB value, determining construction by 1R.To synthesize principium:Peroration :[1]Duality system activator of plant acid and p-toluene-sulfo acid is compare idea activator that was the lower alkyl polyglycosides is firstly formed by reaction of lower alcohol with glucose then exchanged with high alcohol to obtain high alkyl polyglycosides. The advantage is that it overcomes agglomeration, there is reaction entirety, high of sugar transform ratio, reaction time short.[2]Most good reaction temperature is 90～ 170℃, the dosage of activator is 0.5%～0.9%, the mated ratio: The APG of glucose basic butane ratio starch is 5:1, the APG of potato starch basic glycol ratio starch is 6:1, the APG of the oleaster starch basic glycol ratio starch is 12:1, the APG of the mealiest starch basic glycol ratio starch is 6:1, the product of complex is good property.[3]The alkyl polyglycosides is the products of surfactant. IR determines the functional group of the products. On the basis of group of the hydrophile and to close on oil, that the feature peak of α-1, 4- glucoside.[4]The capillary tension of the APG is 26.8～31.0mN/m, the HLB value is 16～18, the products is better emulsifying agent of water- solubility. (O/W).