Biotransformation of l‐menthol by twelve isolates of soil‐borne plant pathogenic fungi (Rhizoctonia solani) and classification of fungi

The microbial transformation of l‐menthol ( 1 ) was investigated by using 12 isolates of soil‐borne plant pathogenic fungi, Rhizoctonia solani (AG‐1‐IA Rs24, Joichi‐2, RRG97‐1; AG‐1‐IB TR22, R147, 110.4; AG‐1‐IC F‐1, F‐4, P‐1; AG‐1‐ID RCP‐1, RCP‐3, and RCP‐7) as a biocatalyst. Rhizoctonia solani F‐1, F‐4 and P‐1 showed 89.7–99.9% yields of converted product from 1 , RCP‐1, RCP‐3, and RCP‐7 26.0–26.9% and the other isolates 0.1–12.0%. In the cases of F‐1, F‐4 and P‐1, substrate 1 was converted to (?)‐(1S,3R,4S,6S)‐6‐hydroxymenthol ( 2 ), (?)‐(1S,3R,4S)‐1‐hydroxymenthol ( 3 ) and (+)‐(1S,3R,4R,6S)‐6,8‐dihydroxymenthol ( 4 ), which was a new compound. Substrate 1 was converted to 2 and/or 3 by RRG97‐1, 110.4, RCP‐1, RCP‐3 and RCP‐7. The structures of the metabolic products were elucidated on the basis of their spectral data. In addition, metabolic pathways of the biotransformation of 1 by Rhizoctonia solani are discussed. Finally, from the main component analysis and the differences in the yields of converted product from 1 , the 12 isolates of Rhizoctonia solani were divided into three groups based on an analysis of the metabolites. Copyright © 2003 Society of Chemical Industry     

基于改进RCP的WLAN集中式请求传输研究

针对数据包对信道的竞争,提出了基于RCP的改进方法,论述了改进协议的基本机制,并通过仿真对改进协议性能进行评价。     

125I-TOC和125I-F-PGA放射化学纯度的测定

为比较3种测定¹²⁵I标记的奥曲肽（TOC）和叶酸-青霉素酰化酶复合物（F-PGA）的放射化学纯度（RCP）的方法是否具有一致性，采用Iodogen法对TOC和F-PGA进行放射性碘标记，并用高效液相色谱法（HPLC）、三氯醋酸（TCA）沉淀法和纸层析法测定标记物的放射化学纯度（RCP），其中TCA沉淀法设4种蛋白浓度以观察其对RCP测定的影响。结果表明，HPLC和纸层析法均能有效分离标记物和游离碘，且HPLC测定这种标记物的RCP最为精确可信。在TCA沉淀法中，用0.2%的小牛血清白蛋白（BSA）测得的RCP最低,而用其它3个BSA浓度测得的RCP则无明显差异（P＞0.05）；当RCP＜10%时，TCA沉淀法与纸层析法测得的RCP间无明显差异（P＞0.05），而要高于HPLC（P＜0.01）；当RCP＞10%时，对¹²⁵I-TOC而言，TCA沉淀法要略低于HPLC和纸层析（P＜0.05），但后2种方法无明显差异（P＞0.05），且对¹²⁵I-F-PGA而言，3种方法无明显差异（P＞0.05）。3种方法两两之间显著相关（r=0.996～0.999，P＜0.001）。     

Transverse stress profiles reconstruction for finite element analysis of laminated plates

The present work focuses on a posteriori, equilibrium based, reconstruction of transverse stress profiles in the finite element analysis of FSDT laminated plates. The accuracy of this reconstruction depends on accuracy of the first and second-order derivatives of the plate stress resultants, which is not guaranteed by most available low-order plate finite elements. To cure this trouble, two different strategies, based on the Recovery by Compatibility in Patches procedure, are here proposed and compared. Numerical results of typical reconstructed transverse stress profiles are presented showing the effectiveness of the proposed approach.     

百万千瓦级核电站轴封型主泵整机集成试验验证优化方案研究

为确保主泵的安全性和可靠性,主泵整机在完成集成设计后需通过试验进行验证。文中介绍了主泵设计与验证的总体思路,提出了主泵工程样机需开展的整机试验项目。基于已有的试验条件,进行了主泵整机集成试验验证方案的优化和可行性分析。分析结果表明,在充分开展主泵各模块、子模块、部件和材料的试验与分析的基础上,可采用小流量试验方案进行主泵整机集成试验验证。      

CPR1000核电站核岛主管道预制焊接变形研究及应用

针对CPR1000核电站核岛主管道用厚壁不镑铜核岛主管道预制焊接中的焊接变形问题,采用理论分析与模拟试验相结合的研究方法,系统地研究了核电站核岛主管道预制焊接不同装配结构的焊接变形特点,确立了主管道预制焊接的反变形措施,保证了主管道预制焊接质量.     

Thermal hydraulic behaviors during loss of RHR system at mid-loop operation of Chinese 300 MWe PWR NPP

Thermal hydraulic behavior of nuclear power plant (NPP) is analyzed by using mechanistic computer code for loss of residual heat removal (RHR) system during mid-loop operation of Chinese 300 MWe two-loop pressurized water reactor is presented. In the absence of recovery of RHR or other accident management measures, the reactor core will be uncovered for a long term resulting in core heat-up, degradation and relocation to the lower plenum. The effectiveness of available mitigate measures, such as safety injection system, gravity feed from refueling water storage tank (RWST) and steam generator (SG) reflux-condensation, are investigated. Coolant injection is highly effective in halting the accident progression and make the core recovered. The cooling capability of SG reflux-condensation has a relationship with different availabilities of steam generators and decay heat power. 6 days after shutdown, 2SG operation can keep the water level at mid-line of hot leg. 12 days after shutdown, both 2SG operation and 1SG operation can keep the water level at mid-line of hot leg. The analyses also indicate that the cooling mechanism of safety injection system is more effective than gravity feed from RWST and SG reflux-condensation. Through confirming the success criteria of SG reflux-condensation, time windows can be devided. Then, event trees for loss of RHR system under mid-loop operation are built with considering the analysis results and abnormal procedure.     

桌面机械臂快速控制原型系统设计与开发

机械臂以其稳定、高精度等特性广泛用于机械、电焊和装配等制造工业,其控制算法已成为工业控制中的研究热点.然而传统的机械臂控制系统设计与开发费时费力,难以满足控制工程师和算法研究者的需求.首先采用快速控制原型技术(RCP),依托高性能计算机,基于Simulink Real-Time组件设计快速控制原型仿真器.进而采用C#语...     

MELCOR/MACCS simulation of the TMI-2 severe accident and initial recovery phases, off-site fission product release and consequences

MELCOR has become the preferred code of the Swiss nuclear industry and of PSI for severe accident analysis, on account of its integrated systems-level approach and validation against experiments and more detailed codes, while MACCS is commonly used by safety authorities for independent assessment of off-site consequences, in particular health effects. The present work arises out of a programme to assess MELCOR independently using empirical data consistent with the recommendations of the OECD/CSNI validation matrix for core degradation codes. The MELCOR 1.8.5RD calculations are based on a model for phases 1 and 2 provided by the code developers but with a simplified thermal hydraulic noding in certain regions and the inclusion of a simple representation of the fission product release and transport pathways. The model has also been extended to simulate phases 3, 4, and the continuing initial period of core recovery and stabilisation. These calculations are a first attempt to demonstrate a MELCOR–MACCS capability to simulate the whole plant accident sequence beyond phase 4, including the containment response and off-site consequences arising from fission product release from the containment. Emphasis is placed on the overall accident evolution and whole plant response, rather than the detailed behaviour. Results are compared with observed and deduced data for the major accident signatures and rough estimates for exposure based on off-site monitoring. The results provide a good basis for the NPP analysis foreseen.     

屏蔽式主泵飞轮方案论证及转子轴系动态性能敏感性分析

为保证核电主泵满足反应堆停堆和断电事故后惰转时间的要求,对屏蔽式主泵机组的转动惯量要求、飞轮配重方案以及主泵转子轴系的动态性能进行分析,给出了飞轮方案,并进行轴承水膜刚度对转子轴系动态性能影响的敏感性分析.