一种区域搜索获取平面光学元件光圈数的方法

提出一种获取平面光学元件光圈数的方法。通过确定一幅干涉条纹图像中三块测试区域及相应的搜索区域,寻找条纹弯曲量的平均值和相应条纹间距的平均值,根据测试区域对应的权重系数,得到被测平面光学元件光圈数的最佳估计值。通过测量标准光圈并比较目视判读结果,得到最大相对误差为5%。实验结果表明,该方法提高了处理干涉条纹图像的适应性,并可替代人工目视判读干涉条纹图像。

Influences of Al doping concentration on structural, electrical and optical properties of Zn0.95Ni0.05O powders

Nanocrystalline Zn0.95 - xNi0.05AlxO (x = 0.01, 0.02, 0.05 and 0.10) diluted magnetic semiconductors have been synthesized by an auto-combustion method. X-ray diffraction measurements indicate that all Al-doped Zn0.95Ni0.05O samples have the pure wurtzite structure. Transmission electron microscope analyses show that the as-synthesized powders are of the size 40 - 45 nm. High-resolution transmission electron microscope, energy dispersive spectrometer and X-ray photoemission spectroscope analyses indicate that Ni2+ and Al3+ uniformly substitute Zn2+ in the wurtzite structure without forming any secondary phases. The Al doping concentration dependences of cell parameters (a and c), resistance and the ratio of green emission to UV emission have the similar trends. (c) 2007 Elsevier B.V. All rights reserved.

Studies of magnetic interactions in Mn-doped β-Ga2O3 from first-principles calculations

The magnetic behavior of Mn-doped beta-Ga2O3 is Studied from first-principles calculations within the generalized gradient approximation method. Calculations show that ferromagnetic ordering is always favorable for configurations in which two Mn ions substitute either tetrahedral or octahedral sites, and the ferromagnetic ground state is also sometimes favorable for configurations where one Mn ion substitutes a tetrahedral site and another Mn ion substitutes an octahedral site. However, the configurations of the latter case are less stable than those of the former. (c) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Consumption of fa cai Nostoc soup: A Potential for BMAA exposure from Nostoc cyanobacteria in China?

Grown in arid regions of western China the cyanobacterium Nostoc flagelliforme - called fa cai in Mandarin and fat choy in Cantonese - is wild-harvested and used to make soup consumed during New Year's celebrations. High prices, up to $125 USD/kg, led to overharvesting in Inner Mongolia, Ningxia, Gansu, Qinghai, and Xinjiang. Degradation of arid ecosystems, desertification, and conflicts between Nostoc harvesters and Mongol herdsman concerned the Chinese environmental authorities, leading to a government ban of Nostoc commerce. This ban stimulated increased marketing of a substitute made from starch. We analysed samples purchased throughout China as well as in Chinese markets in the United States and the United Kingdom. Some were counterfeits consisting of dyed starch noodles. A few samples from California contained Nostoc flagelliforme but were adulterated with starch noodles. Other samples, including those from the United Kingdom, consisted of pure Nostoc flagelliforme. A recent survey of markets in Cheng Du showed no real Nostoc flagelliforme to be marketed. Real and artificial fa cai differ in the presence of beta-N-methylamino-L-alanine (BMAA). Given its status as a high-priced luxury food, the government ban on collection and marketing, and the replacement of real fa cai with starch substitutes consumed only on special occasions, it is anticipated that dietary exposure to BMAA from fa cai will be reduced in the future in China.

An ELISA-like time-resolved fluorescence immunoassay for microcystin detection

Background: A time-resolved fluorescence immunoassay (TRFIA), based on anti-microcystin-LR (MCLR) monoclonal antibodies (MAbs) and europium-labeled antimouse IgG conjugate, was first developed for microcystin detection. Methods: Anti-MCLR MAbs were prepared by a standard method, and the attained MAbs showed a good cross reactivity with MCLR, MCRR and MCYR. The TRFIA was performed in an indirect competitive mode. The detection method of TRFIA was compared with indirect competitive enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC). Results: The TRFIA exhibited a typical sigmoidal response for MCLR at concentrations of 0.005-50 ng/ml, with a wide quantitative range between 0.01 and 10 ng/ml, indicating the broadest detective range and the most sensitive of all the methods for microcystins (MCs) detection. Additionally, the TRFIA maintained good reliability through its quantitative range, as evidenced by low coefficients of variation (1.6-12.2%). The toxin data of algal samples assayed from TRFIA were in the same range as those with ELISA and HPLC, implying that the method was reliable and practical for the detection of MCs. Conclusions: The TRFIA may offer a valuable alternative or a substitute for conventional ELISA for microcystin detection. (C) 2004 Elsevier B.V. All rights reserved.

Interface as the origin of ferromagnetism in cobalt doped ZnO film grown on silicon substrate

We have investigated the magnetic properties of Co-doped zinc oxide (ZnO) film deposited on silicon substrate by magnetron sputtering. Co ions have a valence of 2+ and substitute for Zn sites in the lattice. By using a chemical etching method, an extrinsic ferromagnetism was demonstrated. The observed ferromagnetism is neither associated with magnetic precipitates nor with contamination, but originates from the silicon/silicon oxide interface. This interface ferromagnetism is characterized by being temperature independent and by having a parallel magnetic anisotropy. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2989128]

First-principle study of extrinsic defects in CuScO2 and CuYO2

Using first-principles methods, we studied the extrinsic defects doping in transparent conducting oxides CuMO2 (M=Sc, Y). We chose Be, Mg, Ca, Si, Ge, Sn as extrinsic defects to substitute for M and Cu atoms. By systematically calculating the impurity formation energy and transition energy level, we find that Be-Cu is the most prominent extrinsic donor and Ca-M is the prominent extrinsic acceptor. In addition, we find that Mg atom substituting for Sc is the most prominent extrinsic acceptor in CuSCO2. Our calculation results are expected to be a guide for preparing n-type and p-type materials through extrinsic doping in CuMO2 (M=SC, y). (C) 2008 Elsevier B.V. All rights reserved.

酸化油固定床酶法合成生物柴油研究

酸化油是油脂工业中以皂脚、油脚经酸化处理得到的产品。它的主要成分是游离脂肪酸及中性油，是生产脂肪酸的重要原料，但生产过程中有水解废水的产生，若将其直接排放，既污染了环境又浪费了资源。生物柴油的主要成分是脂肪酸甲酯（fatty acid methyl ester，FAME）。它具有原料丰富而且可再生、可生物降解、无毒、不含芳香烃、二氧化硫等污染物、燃烧排放低、闪点高、运输储存安全等特点。作为石化柴油的潜在替代能源，生物柴油因其独特的优越性和现实的需求越来越受到关注。利用酸化油生产生物柴油不仅可以缓解生物柴油原料不足问题，还可解决酸化油所带来的环境问题。

The convertion of acid oil to biodiesel by use of immobilized Candida lipase absorbed on textile cloth was studied in a fixed bed reactor, which can not only reduce the environmental pollution of acid oil, but also produce a substitute for petroleum diesel. The acid oil mixed with methanol was pumped into three fixed bed reactors in series, and the methanol was added with the molar flow rate same as the acid oil in each reactor. The effects of enzyme content, solvent content, water content, flow rate of reactant and temperature on the enzymatic reaction were analyzed. The result of orthogonal experiments indicates that the optimal transesterification can be performed under the following conditions： immobilized lipase content in acid oil, 20% ; hexane content in acid oil, 10% ; water content in acid oil, 10%, reaction temperature, 50 ℃ ; and flow rate of reactant, 0.08 g/rain. Under these conditions, the FAME content of 90.18% in the product is obtained. The immobilized lipase can be reused with relatively stable activity after glycerol being removed from the surface. By refining, most of the chemical and physical properties of biodiesel will meet the American and Germany biodiesel standards and exceed the Chinese standard of 0^# petroleum diesel except for carbon residue, density and kinematic viscosity.

Synthesis of biodiesel from waste cooking oil using immobilized lipase in fixed bed reactor

Waste cooking oil (WCO) is the residue from the kitchen, restaurants, food factories and even human and animal waste which not only harm people's health but also causes environmental pollution. The production of biodiesel from waste cooking oil to partially substitute petroleum diesel is one of the measures for solving the twin problems of environment pollution and energy shortage. In this project, synthesis of biodiesel was catalyzed by immobilized Candida lipase in a three-step fixed bed reactor. The reaction solution was a mixture of WCO, water, methanol and solvent (hexane). The main product was biodiesel consisted of fatty acid methyl ester (FAME), of which methyl oleate was the main component. Effects of lipase, solvent, water, and temperature and flow of the reaction mixture on the synthesis of biodiesel were analyzed. The results indicate that a 91.08% of FAME can be achieved in the end product under optimal conditions. Most of the chemical and physical characters of the biodiesel were superior to the standards for 0(#)diesel (GB/T 19147) and biodiesel (DIN V51606 and ASTM D-6751).

Characterization of Phosphorus Diffused ZnO Bulk Single Crystals

Phosphorus was diffused into CVT grown undoped ZnO bulk single crystals at 550 and 800℃ in a closed quartz tube. The P-diffused ZnO single crystals were characterized by the Hall effect, X-ray photoelectron spectroscopy （XPS）, photoluminescence spectroscopy （PL）, and Raman scattering. The P-diffused ZnO single crystals are n-type and have higher free electron concentration than undoped ZnO, especially for the sample diffused at 800℃. The PL measurement reveals defect related visible broad emissions in the range of 420-550nm in the P-diffused ZnO samples. The XPS result suggests that most of the P atoms substitute in the Zn site after they diffuse into the ZnO single crystal at 550℃ ,while the P atom seems to occupy the O site in the ZnO samples diffused at 800℃. A high concentration of shallow donor defect forms in the P-diffused ZnO,resulting in an apparent increase of free electron concentration.

氮杂环化合物的绿色合成研究

氮杂环化合物大多数都是具有生理活性的物质，例如喹喔啉化合物与苯二氮卓类化合物，因此研究氮杂环化合物骨架的构建方法具有一定意义。绿色化学的迅速发展迫切要求化学家发展清洁、经济和环境较友好条件下的有机合成方法。其中，水相反应与绿色固体酸催化剂的使用都是实现绿色有机合成的重要途径，它们非常具有潜力，近些年受到了广泛关注。本论文的主要工作是围绕水相及固体酸催化条件下两类具有生物活性的含氮杂环小分子的合成方法而开展的，具体包括以下内容： 1. 研究和探索出了两类绿色固体酸催化剂蒙脱土（Mont. K-10）和杂多酸(H4SiW12O40), 在水相条件下成功合成出喹喔啉化合物的有效方法。两个催化体系都以无毒无公害的水作反应溶剂，实验条件温和，操作安全简便，反应速度快，底物普适性强，产率高，且产物易分离收集。两类固体酸催化剂，对设备腐蚀性小，可回收循环使用，对环境无公害; 蒙脱土催化大部分底物能得到当量产率的产物，硅钨酸催化催化剂负载量小。 2. 实现了无溶剂条件下，以杂多酸（H3PW12O40）作催化剂，高效合成1,5-苯二氮卓衍生物的合成方法。该催化体系具有以下一些优势：实验条件温和，反应速度较快，底物普适性良好，产物易分离收集，反应过程中没有加入其它有机溶剂，绿色环保。 ‘Green Chemistry’ is currently a major issue of modern chemistry. It is widely acknowledged that there is a growing need for more environmentally acceptable processes in the chemical industry. New green catalysts and green reaction media are the important and efficient strategies in green chemistry. New green catalysts include solid acid catalysts, solid base catalysts, metal catalysts not only possess higher activity and selectivity, but also are easily separated from reaction system. Green reaction media include water, supercritical fluids and ionic liquids can not only substitute traditional toxic and harmed organic solvents, but also improve reaction activity and selectivity. Meanwhile water is a promising green reaction medium for use in modern chemistry because it has a number of advantages such as the cheapest solvent available on earth, being non-hazardous and non-toxic to the environment. Solid acids had also attracted much attention for realizing green chemistry due to their unique acidity, high activity and efficiency as organic catalysts. Nitrogen-containing heterocyclic compounds of different ring sizes such as quinoxaline and benzodiazepine are the important pharmacologically active compounds. Due to the wide biological significance of these compounds, the synthesis of these types of compounds have received a great deal of attention. Despite the large availability of methods to construct nitrogen-containing heterocyclic compounds, there is still a strong need to further explore green methods to efficiently and safely synthesize these compounds. Thus, we aim at developing efficient and green methodology for the synthesis of quinoxaline and benzodiazepine carried out under water condition with solid acid catalysts. The contents of this dissertation are listed as the following: 1. We have developed two catalytic systems for the synthesis quinoxaline via the condensation of an aryl 1,2-diamine with a 1,2-diketone compound in the presence of Mont. K-10 or H4SiW12O40 as a catalyst in water solvent. Both of these two methods can be applied to wide range of substrates, tolerating aryl 1,2-diamine/1,2-diketone with the electron donating/drawing substituent. Operational simplicity, the ambient conditions, use of an economically convenient catalyst, use of water as a desirable solvent, high yields and short reaction times are the key features of these two protocols. 2. We developed a convenient and efficient protocol for the synthesis of a variety of 1,5-benzodiazepines in high yields via condensation of aryl o-phenylenediamine derivatives with a variety of ketones using H3PW12O40 as a green recyclable and heterogeneous catalyst under solvent-free condition. The simple experiment procedure combined with ease of recovery and reuse of this catalyst make this procedure quite simple, more convenient and environmentally benign.