两性霉素B菌种选育及发酵工艺研究

为了提高两性霉素B(amphotericin B,AmB)的产量,降低生产成本,满足市场需求,采用紫外诱变和常压室温等离子体(atmospheric and room temperature plasma, ARTP)诱变的复合诱变方法进行菌株选育。首先,对结节链霉菌出发菌株A318-10进行复合诱变;然后,筛选高产菌株,并利用软件Design-Expert 12对显著效应因子进行Box-Behnken Design试验设计,得到最优发酵配方;最后,在1 L摇瓶及50 L发酵罐中进行发酵优化配方验证。结果表明,在紫外诱变60 s并ARTP诱变35 s后,筛选得到了高产菌株20-2-15,其最优发酵配方为葡萄糖94.6 g/L、中温豆粉27.7 g/L、淀粉24.1 g/L;在最优配方下,结节链霉菌1 L摇瓶和50 L发酵罐的发酵最高水平分别为18 968μg/mL和21 257μg/mL,比原始配方分别提高了32.6%和29.4%。研究结果应用于规模化生产后,有利于降低成本、提高企业竞争力。     

脉冲强光技术选育林可霉素高产菌株

文章采用脉冲强光技术诱变处理林肯链霉菌,筛选出性状优良的菌株,并初步分析其诱变机理,探究脉冲强光诱变林肯链霉菌的可行性,结合链霉素抗性筛选的方法选育林可霉素高产菌株。     

万古霉素高产菌株选育及发酵配方优化

为了提高东方拟无枝酸菌产万古霉素的发酵单位,降低生产成本,采用紫外诱变、常压室温等离子体诱变对东方拟无枝酸菌出发菌株V19-02进行诱变处理,通过筛选链霉素抗性突变菌株,选育高产菌株;通过对发酵培养基中碳源和氮源进行筛选,选取葡萄糖、淀粉、低温豆粉、酵母粉4个因素进行均匀设计。结果表明,获得的高产菌株V19-1-07摇瓶发酵单位提高33.7%,且具有良好的传代稳定性;优化后的培养基配比质量分数为葡萄糖8.0%、淀粉1.0%、低温豆粉1.0%、酵母粉4.0%、氯化钠1.0%、磷酸二氢钾0.1%;小试结果证明,优化配方可使50 L罐发酵单位平均达到14 110 μg/mL,比原始配方提高了28.9%。因此,研究获得的高产菌株V19-1-07可应用于万古霉素工业化发酵生产,以帮助企业降低成本,进一步提高竞争力。     

基于开路电压预测的SOC估算方法

为了得到电池的荷电状态(SOC),提高其测算精度,更广泛适用于电动汽车能量管理系统,通过对锂电池进行恒流充、放电实验方法得到SOC和锂电池开路电压的曲线关系,然后将放电后的电池充分静置得到电压自恢复曲线的分析,再结合锂电池等效电路模型,应用Matlab拟合出锂电池开路电压曲线,从而推导出开路电压的计算公式,完成开路电压的预测。最后将实验结果与理论分析进行了对比,进一步验证了理论和仿真建模的正确性。这种方法克服了开路电压法测量时间长的缺点,能够准确地计算SOC,对电池管理系统有重要意义。     

关于油田注水水质标准及水质评价的探讨

通过对胜利油田注水水质标准的研究，以及对油田注水水质研究及评价工作中存在问题的分析。指出我国已注水开发油田必须以矿场水质研究及评价为主，在此基础上，结合室内研究成果，才能正确地确定油田所需最佳水质标准及其经济性。简要阐述了矿场水质研究方法、内容及评价方法。     

用能量方法求解一次超静定杆系问题

根据功能原理建立能量补充方程,并利用静力平衡方程,求解一次拉压超静定问题。该方法同时可用于扭转、弯曲等一次超静定问题的求解。     

磺化卟啉合成及其在痕量金属离子测定中的研究进展

针对水溶性磺化卟啉在痕量组分的测定中可作为超高灵敏显色剂,重点介绍了磺化卟啉的合成方法及其在痕量金属离子测定中的研究进展。     

The effects of board human and social capital on investor reactions to new CEO selection

This study extends work on independent directors to examine the influence of their human capital and social capital on investor reactions to the board's CEO selection decision. We predict that human capital, as represented by the board's CEO experience and industry experience, and social capital, as represented by directors' co‐working experience on the board and external directorship ties to other corporate boards, will influence the stock market reactions to new CEO appointments. In a sample of 208 new CEO appointment events in U.S. manufacturing firms between 1999 and 2003, we found that the stock market reacted favorably to the appointments made by boards with higher levels of human and social capital. We also found that the effect of internal social capital was stronger when the new CEO was an insider rather than an outsider. The implications of the results for director selection and CEO succession are discussed. Copyright © 2010 John Wiley & Sons, Ltd.     

Estimating the final priority ratings of engineering characteristics in mature-period product improvement by MDBA and AHP

Quality function deployment (QFD) has been widely used to translate customer requirements (CRs) into engineering characteristics (ECs) in product improvement. Product planning house of quality (PPHOQ) is of fundamental and strategic importance in the QFD system. In the construction process of the PPHOQ of mature-period (MP) product, correctly estimating the final priority ratings of ECs is essential, because it will largely affect the target value of ECs for improvement. To exploit competitive information of MP products, this paper develops a comprehensive and systematic methodology to rate the final priority of ECs for MP product improvement. The proposed method is on the basis of maximal deviation based approach (MDBA) for dealing with the corporations' performance estimations of ECs, and it integrates AHP and scale method for analyzing the priority rating of achieving the improvement goal of performance evaluation (IGPE) of each EC. Finally, a case study is provided to illustrate the effectiveness of the proposed method.     

Clarifying the conditions and limits of the contributions of ordinary and dynamic capabilities to relative firm performance

Strategy scholars have argued that capabilities can influence firm performance through a variety of means and mechanisms. However, the role of capabilities and their proposed contributions have been narrowly theorized and insufficiently tested. We contribute to resolving these issues by considering the conditions under which ordinary and dynamic capabilities contribute to higher relative firm performance. We do so by examining the positive and negative contributions of capabilities to relative firm performance as well as the effects of environmental dynamism and the degree of capability heterogeneity. We utilize measures of relative firm performance at both the process and firm level within a sample of Chilean firms, which due to a dynamic environment allows for a clearer link between the environment and the use of capabilities. We find that environmental dynamism negatively affects the contribution of ordinary capabilities and positively affects the contribution of dynamic capabilities to relative firm performance. Further, heterogeneity strengthens the contribution of dynamic capabilities to relative firm performance, but is less important for ordinary capabilities. Interestingly, we find support for the direct effects of capabilities to be stronger with a process‐level performance measure, whereas the influences of environmental dynamism and heterogeneity are stronger with a firm‐level measure. Copyright © 2010 John Wiley & Sons, Ltd.     

产业技术选择与产业技术生态环境的耦合效应分析

技术选择问题是技术经济学研究的核心问题。技术选择在技术转移、技术扩散与技术变迁过程中起着重要作用。是发展中国家技术能力发展的首要阶段。本文从生态学角度,系统分析了产业技术选择与技术生态环境耦合效应,并以吉林省37个工业产业研究对象进行了实证研究。实证结果显示,吉林省工业产业中技术选择与技术生态环境之间不匹配现象普遍存在,超过80%产业耦合效应处于失调状态,并且产业规模是制约产业选择技术水平的约束因素。     

阿莫西林克拉维酸钾片含量测定方法的改进

为解决实际应用中克拉维酸钾峰与后相邻杂质的分离度达不到要求的问题,建立了一种同时测定阿莫西林克拉维酸钾片中阿莫西林和克拉维酸钾含量的新方法,采用反相高效液相色谱法(RP-HPLC),Ultimate AQ-C_(18)色谱柱(4.6mm×250 mm,5μm),以pH值为4.4的0.05 mol/L磷酸二氢钠缓冲液为流动相,柱温为35℃,流速为1.0mL/min,检测波长为220nm。结果表明:阿莫西林和克拉维酸钾两主峰与相邻杂质得到完全基线分离,分离度大于1.5;克拉维酸钾对照品溶液质量浓度为0.050 0~0.500 1mg/mL时与峰面积的线性关系良好(r=0.999 8),平均回收率(n=9)为100.14%,RSD值为0.24%;阿莫西林对照品溶液质量浓度为0.100 0~1.000 1mg/mL时与峰面积的线性关系良好(r=0.999 9),平均回收率(n=9)为100.45%,RSD值为0.17%。与原有的《中华人民共和国药典》方法相比,新的阿莫西林克拉维酸钾片含量测定方法专属性好,准确度高,操作简便快捷,结果可靠,可作为一种质量控制方法。     

瞬变电磁法在矿井防治水中的应用

本文主要阐述了瞬变电磁法(TEM)在探测神华乌海能源有限责任公司老石旦煤矿采空区积水中的应用,利用对含水体敏感、分辨率高的瞬变电磁法,根据该地区物性地质条件,探测测区内采空区积水范围及煤系地层的含水情况,为矿井防治水工作的合理实施提供参考依据。