四川盆西平原区裸土扬尘中Pb、Cd化学形态的生物有效性

为探究四川盆西平原区裸土扬尘中Pb、Cd总质量分数与其生物有效性的规律,在构建的"阳离子型污染物土壤表层运移行为研究系统"内进行模拟起尘试验,对土壤样品进行Pb、Cd模拟污染试验,结果表明:试验条件下,四川盆西平原区裸土扬尘颗粒物中Pb、Cd的总质量分数随着粒径的减小而增大,其中Pb的化学形态以碳酸盐结合态为主(44....     

加强信息资源建设搭建数字化资源平台

文章对华北电网公司数字化图书馆的功能特点、资源建设情况及系统采用的关键技术等进行了简要介绍,从侧面论述了该数字化图书馆信息量大、专业性强、技术先进,是各类专业技术人员、管理人员日常工作中获取科技、管理知识的窗口和渠道。     

China’s Oil and Gas Policy in 2010

China has mapped out and adopted a series of energy policies during the 11th Five-Year Plan period and achieved good results,and thus accomplished the task of saving energy and reducing emissions,sped up energy development and optimized     

Development of High Deformability Pipeline Steel

Based on strain-based design, high deformability X70 high strength pipeline steel with dual-phase microstructure has been developed, which can be laid in the seismic, the cold or the deepwater region. The results illustrated that the developed X70 steel has the stress-strain curve like round house and it shows good anti-transformation characteristic, high uniform deformation(≥10%), enhanced n-value(≥0.10), and the low yield-tensile ratio Y/T(≤0.85). The dual-phase microstructure of ferrite and bainite conta...     

Cobalt-iron cyanide hollow cubes: Three-dimensional self-assembly and magnetic properties

Cobalt-iron cyanide hollow cubes have been synthesized via a poly(vinylpyrrolidone) assisted solvothermal route. A unique formation process: self-assembly followed by Ostwald ripening process, has been put forward to take account for the construction of hollow cubes. The rod-like nanocrystals first assemble as porous cubes via an oriented attachment process. Then, the porous cubes undergo an Ostwald-ripening process, which create interior spaces and result in the formation of hollow cubes. The magnetic property investigation reveals that K_0.22Co_0.58Fe_2.2(CN)₆ hollow cubes exhibit a ferromagnetic behavior.     

A Novel Nanoparticle‐Based Disposable Electrochemical Immunosensor for Diagnosis of Exposure to Toxic Organophosphorus Agents

A novel disposable electrochemical immunosensor for highly selective and sensitive detection of organophosphorylated butyrylcholinesterase (OP‐BChE), a specific biomarker for exposure to toxic organophosphorus agents, is presented. In this new approach, zirconia nanoparticles (ZrO₂) were employed to selectively capture the OP moiety of OP‐BChE adducts, followed by quantum dot (QD)‐tagged anti‐BChE antibodies for amplified quantification. The captured CdSe‐QD tags can be sensitively detected by stripping voltammetry using an in situ bismuth‐plating method. The OP agent, diisopropylfluorophosphate (DFP), was selected to prepare OP‐BChE adducts in various matrices. The formation of OP‐BChE adducts in plasma sample was confirmed using mass spectroscopy. The developed electrochemical immunosensor demonstrates a highly linear voltammetric response over the range of 0.1 to 30 nM OP‐BChE, with a detection limit of 0.03 nM (based on signal/noise = 3), coupled with a good reproducibility (relative standard deviation 4.5%). Moreover, the immunosensor has been validated with biomonitoring of OP‐BChE adducts in the plasma samples. This novel nanoparticle‐based electrochemical immunosensor thus provides an alternative way for designing a sensitive and cost‐effective sensing platform for on‐site screening/evaluating exposure to a variety of OP agents.     

Effects of phospholipid hydroperoxide glutathione peroxidase mRNA expression on meat quality of <Emphasis Type=Italic>M. longissimus dorsi</Emphasis> in pigs

Antioxidant enzymes protect muscle tissues against oxidation from reactive oxygen species and increase the stability of the muscle. Phospholipid hydroperoxide glutathione peroxidase (GPx4) is an important antioxidant enzyme in muscle tissue. So the aim of this study was to identify the effects of mRNA expression level of GPx4 gene on meat quality properties in Longissimus dorsi of three pig breeds. Total 36 pigs (12 pigs for each breed) were used to measure the meat quality properties and to analyze the expression levels of GPx4 gene by quantitative real-time PCR. The results showed that meat quality, GPx4 activity, and GPx4 mRNA levels were affected by pig breeds. There were the lowest expressible moisture, drip loss, and cooking loss in Laiwu Pig among the three breeds, and also there were the highest GPx4 activity and the expression levels of GPx4 gene in Laiwu Pig compared with the other two pig breeds. Analysis of meat samples divergent for water-holding capacity identified highly negative associations between expressions levels of GPx4 gene and expressible moisture, drip loss and cooking loss. These results suggest that the higher mRNA expression level of GPx4 gene up-regulate the water-holding capacity and the activity of GPx4, and the expression of GPx4 gene plays an important role in physiological changes related to the meat quality properties and the mechanisms of the antioxidant ion of meat.     

A new sheet metal forming system based on incremental punching, part 2: machine building and experiment results

The paper is the second of the two papers on a new sheet metal forming system of incremental punching. In the first paper, the mechanics model is introduced, and the computer simulations are carried out. This paper consists of two parts: the design and building of an incremental punching machine and experiment results. The machine is a three-axis computer numerical controlled (CNC) machine with a high-speed hydraulic punching head. Given a part, the punch path can be generated using commercial CAM systems with some modifications. Then, the machine takes over forming the part punch by punch. The formability of this system is also investigated giving the maximum forming angle. Following the first paper, two examples are studied in details. The experiment results indicate that the new system is effective for sheet metal rapid prototyping. Finally, some future research topics are discussed.     

CS夹芯板抗弯性能的试验研究

通过CS夹芯板抗弯性能的试验,重点研究织物加强对改善夹芯板抗弯及抗裂性能的作用。试验研究表明,织物加强的CS夹芯板具有很好的抗弯抗裂性能。并根据受弯机理分析,提出相应的开裂弯矩和极限弯矩计算公式,计算结果与试验结果吻合较好。