Multiple Metal–Metal Bond or No Bond? The Electronic Structure of V2O2

Detailed knowledge of the electronic structure of vanadium oxide clusters provides the basis for understanding and tuning their significant catalytic properties. However, already for the simple four‐atom V₂O₂ molecule, there are contradictory reports in the literature regarding the electronic ground state and a possible vanadium–vanadium bond. We herein show through a combination of experimental (matrix isolation) studies and theoretical results that there is a multiple vanadium–vanadium bond in this benchmark vanadium oxide molecule.     

制备高效液相色谱分离纯化系统的研制与开发

介绍一种基于柱层析技术、高效液相色谱技术于一体的计算机智能控制全自动、高性能的化学物质纯化系统。该系统属于高压制备高效液相色谱,采用模块化设计模式,各模块经由计算机工作站软件统一协调,实现进样、分离、馏分收集自动化。该系统应用于中药复杂成分分离、提取和纯化的效率高、馏分损失少、样品回收率高。     

窖泥己酸菌的分离培养与诱变选育

泥窖己酸菌产生的己酸是浓香型大曲酒主体香成分的前体物质之一。从老窖泥中分离纯化出一株产酸能力较高的己酸菌GS5,以其为亲株,通过紫外诱变(照射功率15W,照射距离30cm,时间为3m in),筛选到1株产酸量提高12%的突变株GSUT3,多次继代培养结果表明其产量稳定。研究还发现GSUT3与亲株之间,GSUT3第1代与第8代之间,其生长变化规律和己酸产量的变化规律表现一致。     

活性污泥中细菌的分离、纯化与培养

建立精品实验项目＂细菌纯种分离和培养＂,以污水处理厂的活性污泥为实验样品,利用浇注平板法、平板划线法对活性污泥中的细菌进行分离、纯化并得到纯菌菌种。通过精品实验项目的研究与探索,丰富了实验教学内容,激发了学生的学习兴趣,巩固了学生的基本实验技能,加深了学生对微生物基础理论知识的理解,促进了学生创新能力的培养和提高。     

3D analysis of in-filled trench as passive barriers for ground vibration isolation

The three-dimensional (3D) problem of the ground vibration isolation by an in-filled trench as a passive barrier is studied theoretically. Integral equations governing Rayleigh wave scattering are derived based on the Green’s solution of Lamb problem. The integral equations are solved accurately and efficiently with an iteration technique. They are used to evaluate the complicated Rayleigh wave field generated by irregular scatterers embedded in an elastic half-space solid. The passive isolation effectiveness of ground vibration by the in-filled trench for screening Rayleigh wave is further studied in detail. Effects of relevant parameters on the effectiveness of vibration isolation are investigated and presented. The results show that a trench filled with stiff backfill material gets a better isolation effect than a soft one, and increasing the depth or width of the in-filled trench also improves its screening effectiveness. The effectiveness and the area of the screened zone are surging with the increase in the length of the in-filled trench. Supported by the National Natural Science Foundation of China (Grant Nos. 50678128 and 50538010) and the Research Fund for PhD Student of Chinese College (Grant No. 20050247030)     

某鸡场鸡传染性法氏囊病弱毒疫苗饮水免疫后发生的一次鸡病的诊断

１９９１年４月上旬，四川某鸡场对３５７０只１３日龄依莎雏鸡作法氏囊病弱毒疫苗饮水免疫，１４日龄时发病死亡９只，到２３日龄９天内共死亡８１４只，病死率达２２．８％。对２０只送检病死鸡的沙门氏菌分离率为１／２０株（５％）．但病料人工感染小白鼠试验为阴性，证明非病原菌所致，用病料与新城疫血清（抑制价１：６４０）作用后接种非免疫健康鸡１组的存活率为７５％，直接接种未与新城疫血清作用病料的２组存活率为５０％，剖检回归本动物试验自然死亡和人为处死的病鸡发现了较为典型的法氏囊病变，由此认为：法氏囊弱毒疫苗饮水免疫是引起鸡群发病死亡的主要原因。     

山东林果害虫病毒研究初报

1986至1989年从山东一些林果害虫中分离出10种病毒,它们是赤松毛虫NPV、侧柏松毛虫NPV、灰斑古毒蛾NPV、古毒蛾NPV、杨尺蠖NPV、双齿绿刺蛾NPV、豆天蛾CPV、扬扇舟蛾CPV、侧柏松毛虫CPV、桃天蛾CPV.     

人参种子生长抑制物质的特性及其分离鉴定

报道了人参种子生长抑制物质的特性及其主要抑制物质的分离提纯，并测定了其结构。     

Physicochemical Properties and Complex Formation Abilities of Large-Ring Cyclodextrins

Large-ring cyclodextrins (LR-CD) are cyclic -1,4-glucanscomposed of nine to more than several hundred glucopyranose units. The firstdefinitive evidence for the existence of LR-CD with a degree of polymerization between 9and 13 was reported in 1965. That LR-CD study did not reveal anything that attracted attention. LR-CD with a degree of polymerization between 9 and 31 were isolated andcharacterized during the past decade, and so began to attract considerable attention. This mini-review summarizes the findings of LR-CD with regard to the potentialfor host-guest interactions and corresponding applications.     

"神舟"五号飞船搭载茅台酒大曲中酵母菌的分离及特性的初步研究

对经“神舟”五号载人飞船搭载的茅台酒大曲中的酵母菌进行了分离，从中筛选出一株产酒精体积分数达6．2％和产酯达0．627g／L的菌株MT-14作为备用菌种资源，初步鉴定为酵母属的酿酒酵母（Saccharamyces Cerevisiae），其发酵特性优于厂家提供的茅台酒酵母JG3220。