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Gene Amplification and high-Level Expression of Human Pro-Urokinase cDNA in Chinese Hamster Ovary Cells

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Science China Chemistry 1994年第3期37卷 310-318页

作者：张宏权李风知俞炜源李秀珍方继明费恩阁黄翠芬 Laboratory of Genetic Engineering Institute of Biotechnology Molecular Genetics Center Beijing 100850 PRC Department of Biochemistry and Molecular BiologyInstitute of Basic Medical SciencesBeijing 1000850 PRC Laboratory of Genetic Engineering Institute of Biotechnology Molecular Genetics Center Beijing 100850 PRC

Human Pro-Urokinase (Pro-UK) is expressed in CHO-DHFR- cells at high efficiency by co-transfecting the mouse dhfr gene and Pro-UK cDNA under the control of the SV40 late promoter. After gene co-amplification, the product level could reach 2-3 μg/106 cells/24 h in the presence of 5×10-6 mol/ L MTX, and the levels can be further raised to 3. 5-4 μg/106 cells/24 h by PMA superinduction. The copy number of Pro-UK cDNA in the genomes of host cells is about 200-300 copies/cell. The Western blot analysis shows that the recombinant Pro-UK has similar molecular weight to its natural counterpart, and also the amidolytic activity of the product is determined by S-2444 assay.

关键词： human Pro-urokinase cDNA CHO-DHFR cells gene co-transfection gene co-amplification PMA superinduction

Preparation and performance research of Ce-TiO_2/KL ball photocatalysts

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Journal of Rare Earths 2014年第9期32卷 849-854页

作者：于晓娟熊领领马国平梁愿刘奎仁 School of Materials and Metallurgy Northeastern University School of Science Changchun University of Science and technology

The Ce-TiO2/KL （diatomite） ball photocatalyst was prepared and characterized based on the pretreated diatomite. The resuits showed that comparing with the crude diatomite, proper pretreatment could significantly improve its SiO2 purity and specific surface area. The surface of diatomite was clear with uniform pore structure and big pore size. With diatomite ball as carder, the supported Ce-TiO2/KL ball photocatalyst was prepared by sol-gel method. The photocatalytic performances of the supported Ce-TiO2/ KL ball and Ce-TiO2/KL powder photocatalysts under various preparation conditions were studied in view of photocatalytic degrada- tion rate of Rhodamine B （Rh B） solution. The degradation rate of the ball photocatalysts for Rh B reached 94.6% and could be reused for many times, which showed much better photocatalytic performance and stability than powder photocatalysts.

关键词： diatomite pretreatment premolding titanium dioxide Ce doping photocatalytic degradation rare earths

Cooperative Computing Techniques for a Deeply Fused and Heterogeneous Many-Core Processor Architecture

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Journal of Computer Science & technology 2015年第1期30卷 145-162页

作者：郑方李宏亮吕晖过锋许晓红谢向辉 State Key Laboratory of Mathematical Engineering and Advanced Computing Wuxi 214125 China

Due to advances in semiconductor techniques, many-core processors have been widely used in high performance computing. However, many applications still cannot be carried out efficiently due to the memory wall, which has become a bottleneck in many-core processors. In this paper, we present a novel heterogeneous many-core processor architecture named deeply fused many-core （DFMC） for high performance computing systems. DFMC integrates management processing ele- ments （MPEs） and computing processing elements （CPEs）, which are heterogeneous processor cores for different application features with a unified ISA （instruction set architecture）, a unified execution model, and share-memory that supports cache coherence. The DFMC processor can alleviate the memory wall problem by combining a series of cooperative computing techniques of CPEs, such as multi-pattern data stream transfer, efficient register-level communication mechanism, and fast hardware synchronization technique. These techniques are able to improve on-chip data reuse and optimize memory access performance. This paper illustrates an implementation of a full system prototype based on FPGA with four MPEs and 256 CPEs. Our experimental results show that the effect of the cooperative computing techniques of CPEs is significant, with DGEMM （double-precision matrix multiplication） achieving an efficiency of 94%, FFT （fast Fourier transform） obtaining a performance of 207 GFLOPS and FDTD （finite-difference time-domain） obtaining a performance of 27 GFLOPS.

关键词： heterogeneous many-core processor data stream transfer register-level communication mechanism hardwaresynchronization technique processor prototype

Microstructural features and precipitation behavior of Ti,Nb and V microalloyed steel during isothermal processing

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Journal of Iron and Steel Research International 2019年第1期26卷 102-111页

作者： Qi Zhou Zhuang Li Zhan-shan Wei Di Wu Jin-yu Li Zhen-yao Shao School of Environment and Chenlical Engineering Shenyang Ligong UniversityShenyang 110159LiaoningChina College of Materials Science and Engineering Shenyang Aerospace UniversityShenyang 110136LiaoningChina State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110004LiaoningChina

Thermal simulations of Ti,Nb and V microalloyed steel were conducled using a thermomechanical simulator,and the microstructural evolution and the precipitation behavior during isothermal processing were *** results show that with increasing holding time,the microstructural constituents change from the martensite and bainitic ferrites to granular bainite and polygonal *** maximum hardness is obtained for the specimen after isothermal holding for 5s due to the martensite strengthening *** hardness of the specimen decreases after isothermal holding for 10s,because the strengthening contribution of fine dispersed precipitates becomes *** hardness values of the specimens increase and then remain high after isothermal holding for 60 and *** is attributed to the contribution of the interphase precipitation hardening to the hardness of the studied *** precipitates in the specimen are coarsened after isothermal holding for 3600s,even though the coarsening is not *** precipitates are fee(***)(N.C)particles and belong to the MX-type *** beneficial effects of precipitation strengthening are *** hardness decreases to a minimum hardness value due to the presence of large amounts of polygonal ferrite after isothermal holding for *** coarse precipitates are the primary origin of the hardness decrease.

关键词： Microalloyed steel Isothermal holding time Microstructural constituent Precipitation Hardness

Molecular cloning, expression analysis and chromosomal mapping of salt-responsive cDNAs in rice (Oryza sativa L.)

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Science China(Life Sciences) 1999年第5期42卷 506-516页

作者：李子银张劲松陈受宜 1. Plant Biotechnology Laboratory Institute of Genetics Chinese Academy of Sciences 100101 Beijing China

By using differential display PCR (DD-PCR) technique, two salt-inducible and one salt-repressed cDNA fragments were isolated from rice. The three cDNA fragments were characterized respectively as partial sequence of rice S-adenosylmethionine decarboxylase (SAMDC) gene, a new member of translation elongation factor lA gene (named REF1A), and a novel gene whose function is unknown (named SRG1). The full-length cDNA of SAMDC gene (named SAMDC1) was further isolated by RT-PCR approach and the deduced polypeptide was found to be homologous to SAMDC proteins of other plants, yeast and human. Northern hybridization revealed that expression of SAMDC1 and REF1A was induced, while SRG1 was dramatically repressed, by salinity stress. Southern blot analysis demonstrated that SAMDC 1 and SRG1 were present as a single copy gene in rice genome, whereas rice REF1A gene was organized as a gene family. The REF1A, SAMDC1, and SRG1 genes were located on chromosome 3,4, and 6 respectively by RFLP mapping approach using ZYQ8/JX17 DH population and RFLP linkage maps.

关键词： rice ( Oryza saliva L.) salt-responsive gene differential display PCR differential expression chromosomal mapping.

Diagnostic Technique of Neutron Doppler Broadening for Indirectly-Driven Implosions

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Plasma Science and technology 2004年第3期6卷 2346-2349页

作者：熊勇丁永坤郑志坚陈铭 Research Center of Laser Fusion China Academy of Engineering Physics Mianyang 621900 China

The neutron Doppler broadening in inertial confinement fusion has been acquired from the time of flight for the neutron, from which the fuel ion temperature can be derived. An ultrafast-quenched plastic scintillation detector was used to measure the time of flight for the neutron at a low-imploded DT neutron yield (5×107-1×108) in the experiment performed on the Shenguang Ⅱ laser facility. The typical temperatures of ablating targets for indirect drive were around 2.8 keV and the uncertainties were ±30 % - ±40%. The detection efficiency of the detector for DT neutrons was calibrated at a K-400 accelerator. The time response function of the detection system was calibrated by imploded neutrons from a DT-filled capsule, which can be regarded as a S function pulsed neutron source due to its much narrower pulse width than that of the measured neutron time-of-flight spectrum.

关键词： neutron Doppler broadening indirect-driven implosions response function ion temperatures

Key issues of multiple access technique for LEO satellite communication systems

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Journal of Systems Engineering and Electronics 2004年第2期15卷 120-125页

作者： WenPingping GuXuemai CommunicationResearchCenter HarbinInstituteofTechnologyHarbin150001P.R.China

The large carrier frequency shift caused by the high-speed movement of satellite (Doppler effects) and the propagation delay on the up-down link are very critical issues in an LEO satellite communication system, which affects both the selection and the implementation of a suitable access method. A Doppler based multiple access technique is used here to control the flow and an MPRMA-HS protocol is proposed for the application in LEO satellite communication systems. The extended simulation trials prove that the proposed scheme seems to be a very promising access method.

关键词： LEO satellites multiple-access protocols flow control Doppler estimation.

Modelling hydrodynamic processes in tidal stream energy extraction

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Journal of Hydrodynamics 2016年第6期28卷 1058-1064页

作者：林杰林斌良孙健陈娅玲 Department of Hydraulic Engineering Tsinghua University

Tidal stream energy is a type of marine renewable energy which is close to commercial-scale production. Tidal stream turbine arrays are considered as the one of the most promising exploitation methods. However, compared to the relatively mature technology of single turbine design and installation, the current knowledge on the hydrodynamic processes of tidal stream turbine arrays is still limited. Coastal models with simplified turbine representations based on the shallow water equation are among the most favorable methods for studying the tidal stream energy extraction processes in realistic sites. This paper presents a review of the progress and challenges in assessing the tidal stream energy.

关键词： tidal stream energy coastal flow field shallow water equations turbine parameterization

Influence of silicon coating on the corrosion resistance of Zn-Al-Mg-RE-Si alloy

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Journal of Rare Earths 2010年第S1期28卷 378-381页

作者：刘奎仁马鹏程蒲年文陈建设韩庆 School of Material and Metallurgy Northeastern University Sichuan Chuanwei Group Ltd.

The electric arc spraying method was used to prepare the Zn-Al-Mg-RE-Si alloy coating with different content of *** corrosion resisting property was measured by copper accelerated salt spray(CASS) and corrosion weightless *** influence of silicon content on the corrosion resisting property was investigated by XRD,SEM,polarization curve and electrochemical impedance spectroscopy(EIS) and the electrochemical property of coating in the corrosion process was *** results showed that the density of coating was improved significantly since the major nonequilibrium glass-like state phase was composed of silicon and other metals existed in the Zn-Al-Mg-RE-Si alloy coating,which prevented the corrosive medium and retarded the corrosion velocity because of compact corrosion products in the corrosion *** Zn-Al-Mg-RE-Si coating had better corrosion resistance than the Zn-Al-Mg-RE because of more positive potential,half corrosion current density and double electrochemical reaction resistance.

关键词： corrosion electric arc spraying CASS weightless corrosion resisting property rare earths