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基质金属蛋白酶组织抑制剂-2基因的人工合成与克隆

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生物技术通讯 2005年第3期16卷 242-244页

作者：闫训友赵洪亮张惟广薛冲熊向华刘志敏军事医学科学院生物工程研究所西南农业大学食品科学学院重庆400716 西南农业大学食品科学学院

根据GenBank报道的基质金属蛋白酶组织抑制剂-2(TIMP-2)氨基酸序列和毕赤酵母偏爱密码子设计,通过化学方法合成得到适合在毕赤酵母中表达的目的TIMP-2基因序列,并将其克隆到质粒pPIC9中,构建了pPIC9-T2表达载体,PCR鉴定及测序结果表明... 详细信息

根据GenBank报道的基质金属蛋白酶组织抑制剂-2(TIMP-2)氨基酸序列和毕赤酵母偏爱密码子设计,通过化学方法合成得到适合在毕赤酵母中表达的目的TIMP-2基因序列,并将其克隆到质粒pPIC9中,构建了pPIC9-T2表达载体,PCR鉴定及测序结果表明得到了正确的TIMP-2基因序列。

关键词：基质金属蛋白酶组织抑制剂人工合成克隆 GenBank 毕赤酵母基因序列偏爱密码子氨基酸序列 PCR鉴定化学方法表达载体质粒测序

Oxidation behavior of boron-containing(Zr,Ti)C_(x)B_(y)solid solution ceramics at 1600℃in air

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Journal of Advanced Ceramics 2023年第10期12卷 1989-2002页

作者： Huilin Lun Yi Zeng xiang xiong Houbu Li State Key Laboratory of Performance and Structural Safety for Petroleum Tubular Goods and Equipment Materials CNPC Tubular Goods Research InstituteXi’an 710077China State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Key Laboratory of Petroleum Tubular Goods and Equipment Ouality Safety for State Market Regulation CNPC Tubular Goods Research InstituteXi’an 710077China

Multicomponent boron-containing carbide coatings(i.e.,(Zr,Ti)C_(x)B_(y))on a C/C composite show good ablation ***,the high-temperature oxidation behavior of this new type of boron-containing(Zr,Ti)C_(x)B_(y)solid solution ceramics has not been clarified *** present work fabricated(Zr,Ti)C_(x)B_(y)solid solution block ceramics by spark plasma sintering,and their oxidation behavior at 1600℃in air(N2–20-vol%O2)was investigated for the first *** effects of boron on the oxidation resistance of(Zr,Ti)C_(x)B_(y)ceramics were *** results indicate that the(Zr,Ti)C_(x)B_(y)ceramics display good oxidation resistance with the parabolic rate law describing the oxidation *** the trace solution of boron(0.5 wt%)into(Zr,Ti)Cx,the oxidation resistance of carbide ceramics is significantly enhanced,leading to a decrease of 30%in the oxidation rate *** formed oxide scale in the(Zr,Ti)C_(x)B_(y)ceramics is dense,and the interlayer shows stronger ability to inhibit inward diffusion of *** addition,the introduction of boron leads to more negative binding energy of(Zr,Ti)C_(x)B_(y)and improves the oxidation resistance of carbides.

关键词： ultra-high-temperature ceramics(UHTCs) (Zr,Ti)CxBy solid solution oxidation behavior oxidation resistance

Development of new ductile iron with super-high thermal conductivity and elongation

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Journal of Iron and Steel Research International 2022年第3期29卷 462-473页

作者： Guang-hua Wang Yan-xiang Li School of Materials Science and Engineering Tsinghua UniversityBeijing100084China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing100084China

The effects of Si content,graphite volume fraction and pearlite volume fraction on the thermal conductivity of ductile iron were studied based on theoretical model *** results showed that the thermal conductivity of ductile iron was more sensitive to Si content compared with the volume fractions of pearlite and *** key method to design and develop high thermal conductivity ductile iron was to control the Si *** 0.9-2.2 wt.%Si content,experimental results showed that with the increase in Si content,the thermal conductivity of ductile iron decreased dramatically,and the yield strength and tensile strength of ductile iron almost linearly increased,but the elongation remained almost *** dependence of thermal conductivity of ductile iron on temperature changed from monotonic decreasing to increasing first and then ***,we broke the common composition range of ductile iron and designed a new high C(≥3.9 wt.%)and low Si(1.0-1.4 wt.%)ductile iron with super-high thermal conductivity and *** thermal conductivity exceeded 40 W/(m K)within 27-300℃,and maintained at 35-40 W/(m K)at 500℃.The elongation was over 25%,and the tensile strength was more than 300 MPa.

关键词： Thermal conductivity Ductile iron Elongation Tensile strength Silicon alloying

A Direct Calculation of Critical Exponents of Two-Dimensional Anisotropic Ising Model

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Communications in Theoretical Physics 2006年第5期45卷 932-934页

作者： xiong Gang WANG xiang-Rong physics Department Beijing Normal University Beijing 100875 China Physics Department Hong Kong University of Science and Technology Clear Water Bay Hong Kong SAR China

Using an exact solution of the one-dimensional quantum transverse-field Ising model, we calculate the critical exponents of the two-dimensional anisotropic classical Ising model （IM）. We verify that the exponents are the same as those of isotropic claesical IM. Our approach provides an alternative means of obtaining and verifying these well-known results.

关键词： iisng model exact solution critical exponent

Evaluation of pelvic lymph node coverage of conventional radiotherapy fields based on bony landmarks in Chinese cervical cancer patients using CT simulation

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2009年第9期10卷 683-688页

作者： xiang ZHANG hua YU Department of Gynecologic Oncology Zhejiang Cancer Hospital Hangzhou 310022 China

Objective： To evaluate the pelvic lymph node coverage of conventional pelvic fields based on bony landmarks in Chinese patients with cervical cancer by using computed tomography （CT） simulation images to contour pelvic vessels as substitutes for lymph nodes location. Methods： A retrospective review of CT simulation images and conventional pelvic radiation planning data sets was performed in 100 patients with cervical cancer at the International Federation of Gynecology and Obstetrics （FIGO） Stage liB to IIIB in our hospital. Pelvic arteries were contoured on CT simulation images, and the outlines of conventional pelvic fields were drawn as defined by the gynecologic oncology group （GOG） after hiding the contours. The distances between the following vessel contours and field borders were measured： D1, the superior border of the anterior/posterior （AP） field and the bifurcation of abdominal aorta; D2, the ipsilateral border of the AP field and the distal end of external iliac artery; and D3, the anterior border of the lateral （LAT） field and the distal end of the external iliac artery. The distances were recorded as positive values if the measuring point was within the conventional pelvic fields, or they were recorded as negative values. Lymph nodes coverage was considered adequate when D1≥0 mm, D2〉17 mm or D3≥7 mm. Results： All patients had at least 1 inadequate margin, 97 patients （97.0%） had 2, and 22 patients （22.0%） had all the 3. On the AP field, 95 patients （95%） had the measuring point, the bifurcation of the abdominal aorta, out of the field （D1〈0 mm）, and all the patients had a distance less than 17.0 mm between the distal end of the external iliac artery and ipsilateral border （D2〈1 7.0 mm）. On the LAT field, 24 patients （24%） had a distance less than 7.0 mm between the distal end of the external iliac artery and anterior border （D3〈7.0 mm）. Conclusion： We observed that conventional pelvic fields based on bony landmarks provided inadequate coverage of pelvi

关键词： Cervical cancer Radiotherapy planning Computed tomography (CT) simulation Lymph nodes

Gamete Recognition in Higher Plants:An Abstruse but Charming Mystery

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Journal of Integrative Plant Biology 2008年第7期50卷 868-874页

作者： xiong-Bo Peng Meng-xiang Sun Key Laboratory of Ministry of Education for Plant Developmental Biology College of Life Sciences Wuhan University Wuhan 430072 China

Although much effort has been made to uncover the mechanism underlying double fertilization, little knowledge has been acquired for understanding the molecular base of gamete recognition, mainly because of technical limitations. Still, progress has been made in terms of the mechanism, including the identification of candidate molecules that are involved in gamete recognition in angiosperms. New cues for gamete recognition have been found by the successful separation of the gametes and construction of gamete-specific cDNA libraries in several species, and the application of molecular approaches for studying this process by mutations. Thus, the topic is considered an abstruse but charming mystery.

关键词： central cell egg cell fertilization gamete recognition sperm cell.

Tensor Couplings of ω- and ρ-Mesons with Nucleons in a Derivative Scalar Coupling Model for Finite Nuclei

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Chinese Physics Letters 2001年第7期18卷 891-893页

作者： GUO hua HU xiang Department of Technical Physics and MOE Laboratory of Heavy Ion Physics Peking UniversityBeijing 100871

Theω-andρ-meson tensor couplings to nucleons in a derivative scalar coupling model for finite nuclei are *** influences of the tensor couplings on the binding energies per nucleon,the root-mean-square charge radii,spin-orbit splittings and single particle energies are *** obtained results show that the spin-orbit splittings for finite nuclei are more sensitive to theω-meson tensor coupling.

关键词： tensor coupling meson

Application of multiwalled carbon nanotubes treated by potassium permanganate for determination of trace cadmium prior to flame atomic absorption spectrometry

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Journal of Environmental Sciences 2007年第10期19卷 1266-1271页

作者： XIAO Jun-ping ZHOU Qing-xiang BAI hua-hua Department of Chemistry University of Science and Technology Beijing Beijing 100083 China Henan Key Laboratory for Environmental Pollution Control School of Chemistry and Environmental Sciences Henan Normal University Xinxiang 453007 China

In this study we investigated the enrichment ability of oxidized multiwalled carbon nanotubes （MWCNTs） and established a new method for the determination of trace cadmium in environment with flame atomic absorption spectrometry. The MWCNTs were oxidized by potassium permanganate under appropriate conditions before use as preconcentration packing. Parameters influencing the recoveries of target analytes were optimized. Under optimal conditions, the target analyte exhibited a good linearity （R^2=0.9992） over the concentration range 0.5-50 ng/ml. The detection limit and precision of the proposed method were 0.15 ng/ml and 2.06%, respectively. The proposed method was applied to the determination of cadmium in real-world environmental samples and the recoveries were in the range of 91.3%-108.0%. All these experimental results indicated that this new procedure could be applied to the determination of trace cadmium in environmental waters.

关键词： multiwalled carbon nanombes (MWCNTs) solid-phase extraction flame atomic absorption spectrometry

Preparation,Properties and Application of C/C-SiC Composites Fabricated by Warm Compacted-in situ Reaction

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Journal of Materials Science & Technology 2010年第3期26卷 283-288页

作者： Peng Xiao Zhuan Li Zibing Zhu xiang xiong State Key Laboratory of Powder Metallurgy Central South University Changsha 410083 China China Aviation Power Plant Research Institute Zhuzhou 412002 China

Carbon fibre reinforced carbon and SiC dual matrices composites （C/C-SiC） show superior tribological properties,high thermal shock resistance and good abrasive resistance,and they are promising candidates for advanced brake and clutch *** microstructure,mechanical properties,friction and wear properties,and application of the C/C-SiC composites fabricated by warm compacted-in situ reaction were *** results indicated that the composites were composed of 50-60 wt pct carbon,2-10 wt pct residual silicon and 30-40 wt pct silicon *** C/C-SiC brake composites exhibited good mechanical *** value of flexural strength and compressive strength could reach 160 and 112 MPa,*** impact strength was about 2.5 kJ·*** C/C-SiC brake composites showed excellent tribological performance,including high coefficient of friction （0.38）,good abrasive resistance （1.10 μm/cycle） and brake steadily on dry *** tribological properties on wet condition could be mostly *** silicon carbide matrix in C/C-SiC brake composites improved the wear resistance,and the graphite played the lubrication function,and right volume content of graphite was helpful to forming friction film to reduce the wear *** results showed that C/C-SiC composites fabricated by warm compacted-in situ reaction had excellent properties for use as brake materials.

关键词： C/C-SiC Ceramic-matrix composites Tribology Warm compacted-in situ reaction