OALib Journal期刊

ISSN: 2333-9721




2018 ( 197 )

2017 ( 206 )

2016 ( 254 )

2015 ( 2950 )


匹配条件: “CHEN Zhong-rong” ,找到相关结果约96024条。
Construction and application of a yeast expression system for thymosin a1
Chen,Feng; Chen,Xiang-Ming; Chen,Zhi; Jiang,Han-Liang; Pan,Xiao-Ping; Hu,Zhong-Rong; Liu,Rong-Hua; Chen,Xiao-Ming;
Biocell , 2005,
Abstract: we want to construct a yeast expression system for thymosin a1 (ta1) to make the orally administered ta1 preparation possible. the whole ta1 dna fragment was obtained by pcr. after being digested with restriction enzymes, it was cloned into pyes2 vector. sequencing was performed to identify the recombinant. the sequence of ta1 in recombinant coincided with the original one reported in genbank. when pyes2-ta1 plasmid was transformed into yeast, galactose instead of glucose was used to induce ta1 expression. western blot was performed to identify the quality of the expressed ta1. dried yeast containing pyest2-ta1 was fed to balb/c mice whose immunities were inhibited by cyclophosphamide in advance. synthesized ta1 peptide was used as positive control and empty yeast was used as negative control. compared with the negative control group, both dried yeast containing pyest2-ta1 and synthesized ta1 peptide can significantly increase the cd8+ level (22.74±1.09 and 18.77±4.72 vs 7.49±2.14, p<0.01), while both of them had little effect on the cd4+ lymphocytes (61.86±6.94 and 65.91±4.78 vs 57.93±10.40, p>0.05). we concluded that a high effective yeast expression system for ta1 was constructed successfully and the ta1 protein expressed by this system can improve cd8+ level in immune inhibited mice.
New triterpenoids from the kernels of Azadirachta indica
Hong-Wei Wang,Jie-Qing Liu,Jin-Xiong Chen,Yuan-Feng Yang,Yu-Xin Yan,Zhong-Rong Li,Ming-Hua Qiu
Natural Products and Bioprospecting , 2013, DOI: 10.1007/s13659-013-0005-z
A Study of Drop-Size Distribution in Precipitation Cloud from Wind Profile Radar

WANG Xiao-lei,RUAN Zheng,GE Run-sheng,CHEN Zhong-rong,

高原气象 , 2010,
Abstract: 对风廓线雷达探测降水时出现的双峰型功率谱密度分布的回波, 进行大气返回信号和降水返回信号的剥离, 由大气返回信号求出环境大气的垂直运动, 导出降水质点下降末速度的功率谱密度分布, 进而求出云体中的雨滴谱分布。对两次降水进行了雨滴谱反演试验, 提取了不同高度上30多份雨滴谱分布, 雨滴谱分布基本上呈现出指数分布形式。指数拟合后求出雨滴谱的浓度参数N0由几百到几千m-3mm-1, 尺度参数λ为3.8~4.5 mm-1。试验中, 还由反演的雨滴谱估算出云中含水量, 得出降水云体中含水量随高度的分布, 与附近多普勒天气雷达观测进行了比较。风廓线雷达与多普勒天气雷达探测到的回波强度随高度分布基本一致, 云中含水量估算的均值基本相同, 而风廓线雷达由雨滴谱估算出的含水量随高度分布可以反映出雨滴谱变化的影响, 随高度分布更为精细。
Study on Bright Band Detection Using Wind Profiler Radar

HUANG Yu-,RUAN Zheng-,GE Run-sheng,CHEN Zhong-rong,

高原气象 , 2011,
Abstract: L-band wind profile is used in coherent accumulation technology to rise radar sounding sensitivity, vertical measurement precipitation cloud body is applied,which can obtain the entire spectrum information of cloud body return signal of high resolution.The wind profiler is used to continuously detect the bright band appeared in stratiform cloud precipitation process on May 14,2009.The variation and evolution characteristics of return signal spectrum parameter(power,average Doppler velocity,speed spectral wi...
A Comparative Study on Radial and Tangential Fretting Damage of Molybdenum Disulfide Bonded Solid Lubrication Coating

ZHU Min-hao,ZHOU Hui-di,CHEN Jian-min,ZHOU Zhong-rong,

摩擦学学报 , 2002,
Abstract: The fretting wear behavior of molybdenum disulfide bonded solid lubricating coating under radial and tangential fretting conditions were investigated by sliding against AISI-1045 steel counterpart. The fretted surfaces of the coating were analyzed by means of scanning electron microscopy, energy dispersive spectrometry, and X-ray photoelectron spectroscopy. The results show that the coating had better wear resistance under radial fretting. No mixed fretting regime existed under the condition of tangential fretting, and the fretted damage of the coating was accompanied by the oxidation of MoS 2, which was strongly dependent on the displacement amplitude. Moreover, the coating under radial fretting behaved similarly as in the partial slip regime of tangential fretting.
Tribological Characteristics between Third Rail and Collector Shoe under Electric Current

DONG Lin,CHEN Guang-xiong,ZHU Min-hao,ZHOU Zhong-rong,

摩擦学学报 , 2007,
Abstract: A new test rig was developed by modifying the clamps and the control system of conventional pin-on-disc tester. The friction and wear characteristics of aluminum-stainless steel composite conductor rail and collector shoe used in metro power supply were investigated on the rig with an electrical current applied across the sliding interface. The morphologies of worn surfaces were observed and analyzed by means of laser confocal scanning microscope and energy dispersive x-ray spectroscopy. Wear mechanisms with electric current were analyzed and discussed based on electric contact theory. Experiment results show that a threshold value of normal stress exists in friction and wear with the variation of electric current. If normal stress is larger than the threshold value, friction coefficients increase with the increasing of electric current, and current enhances mechanical wear. If normal stress is smaller than the threshold induces electric arc erosion. value, friction coefficients decrease with the increasing of electric current, and current Wear mechanisms of the part with current are dominated by adhesive and abrasive wear, but the material volume loss caused by electric arc erosion is much larger than it caused by mechanical wear. For a certain velocity, the threshold value of normal stress is an optimum normal stress, which makes not only electrical power supply stable but also mechanical wear lower and railway running cost saved.
Endovascular therapy of ischemic cerebrovascular disease
MIAO Zhong-rong,MA Ning
Chinese Journal of Contemporary Neurology and Neurosurgery , 2013, DOI: 10.3969/j.issn.1672-6731.2013.03.003
Study on Redox Buffering of Landfill Leachate Contaminated Aquifer Sediments

DONG Jun,ZHAO Yong-sheng,WANG Yi-hong,CHEN Zhong-rong,LIU Ying-ying,HAN Rong,

环境科学 , 2006,
Abstract: A soil column filled with sandy soil was constructed to investigate redox buffering capacity of aquifer sediments and its variation in different redox zones.Results indicated that with the aggravating of landfill leachate pollution,the oxidation capacity(OXC) of sediments was decrease,and the reduction capacity(RDC) of sediments was increase.In uncontaminated aquifer sediments,Fe3+ was a main component of OXC,and account for about 70.5% of OXC;TOC was a main component of RDC,and account for about 98.7% of RDC.In anaerobic environment,large fraction of amorphous Fe3+ and part of crystalline Fe3+ were reduced,and the reduced product was mainly precipitated as FeCO3 and FeS.In methanogenic zone/sulfate reduction zone and iron reduction zone,deposit of Fe2+ led to ion-exchangeable Fe2+ content increased from 0.5% of uncontaminated aquifer sediments to 3% and 1.84% respectively.Therefore,sediment-bound iron may act as a very significant redox buffer in polluted aquifer,the reduction of Fe3+ and fowling precipitation and ion exchange onto the sediment of Fe2+ substantially reduces the size of the anaerobic leachate pollution plume,which may contribute substantially to the buffering of entering reduced species.
Fretting Wear Properties of TiO2 Nanotube Layers with Different Diameters

LUO Rong,FENG Bo,QU Shu-xin,LU Xiong,CHEN Jian-min,ZHOU Zhong-rong,

摩擦学学报 , 2010,
Abstract: Three groups of TiO2 nanotube layers with different inner diameters were fabricated on titanium substrate by anodization. Morphology, microhardness, nanohardness and roughness of specimen surfaces were analyzed by a scanning electron microscope, hardness instrument and surface roughometer. The fretting wear tests of specimens against a UHMWPE ball were carried out in air on a PLINT fretting fatigue machine using the ball / plane contact under four normal loads respectively. Results suggested that coefficients of friction decreased as normal load increased for the same frictional pair. The TiO2 nanotube layers reduced the coefficients between Ti specimen and UHMWPE. Under different normal load, the coefficients increased as the nanotube diameter increased. The friction coefficients of nanotube specimens were lower than that of the contrast. In sliding against UHMWPE, TiO2 nanotube layers had good of load-bearing, anti-stripping and wear-resistant properties. The wear mechanism of the frictional pair involved abrasive wear and material loss on surface layer resulted from UHMWPE plastic deformation.


物理学报 , 1960,
Abstract: 本文对钇-镱(Y-Yb)柘榴石型铁氧体系统Y3-xYbxFe3O12 (其中x=0,0.75,1.50,2.25和3.00)的磁性进行了研究。采用共同沉淀和氧气中烧结的方法制备样品,进行了X射线粉末照相的观测,测量了静态磁滞迴线,起始磁导率(500千赫),电阻率,鲍和磁化强度,居里点及分米波段磁谱。实验结果表明:整个系统都是单相的柘榴石型结构,所有样品都具有实际密度大(>90%理论密度)、电阻率高(109—1010欧姆·厘米)的特点。

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