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A Breakthrough of Primary Structure in Indeterminate Analysi--Irregular Force Method and Irregular Displacement Method
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作者 Ren Song 《Journal of Civil Engineering and Architecture》 2010年第12期47-55,共9页
As the strict limitation of primary structure in traditional force method and displacement method in indeterminate analysis may lead to complicated high-order linear equations, a breakthrough of the limitation, i.e., ... As the strict limitation of primary structure in traditional force method and displacement method in indeterminate analysis may lead to complicated high-order linear equations, a breakthrough of the limitation, i.e., the application of irregular force method and irregular displacement method, would be introduced in this paper to ease the difficulty of hand computations. By using hyperstatic primary structures and partly chained primary structures, the primary structures of force method and displacement method are reformed, and the order of the system is decreased. The technique is explained through examples. The significance of the new method is summarized. 展开更多
关键词 assistant diagram irregular force method hyperstatic primary structure irregular displacement method partly chained primary structure.
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Purification and Primary Structure Determination of a Novel Polypeptide Isolated from Mistletoe Viscum coloratum 被引量:2
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作者 JingLinKONG XiuBaoDU ChongXuFAN YingCAO HuiJIANG JianFuXU XiaoJunZHENG 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第11期1311-1314,共4页
A novel polypeptide was isolated from mistletoe Viscum coloratum. The primary structure of the polypeptide named viscotoxin B2 was determined to be KSCCKNTTGRNIYNT CRFAGGSRERCAKLSGCKIISASTCPSDYPK by Edman degradation.... A novel polypeptide was isolated from mistletoe Viscum coloratum. The primary structure of the polypeptide named viscotoxin B2 was determined to be KSCCKNTTGRNIYNT CRFAGGSRERCAKLSGCKIISASTCPSDYPK by Edman degradation. Viscotoxin B2 shared high sequence homology with viscotoxins isolated from Viscum album. Pharmacological experiments showed that viscotoxin B2 had distinct cytotoxic activity on tumor cells. Viscotoxin B2 could be used as a leading compound in cancer therapy. 展开更多
关键词 Viscum coloratum ISOLATION primary structure viscotoxin.
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Cubic Mesoporous Aluminosilicate with Primary Structure Units of Zeolite Beta in the Pore Wall
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作者 Gong LI Qiu Bin KAN +1 位作者 Tong Hao WU Jia Hui HUANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第6期637-640,共4页
Mesoporous aluminosilicate with cubic ordered structure was synthesized by two-step crystallization, which showed stronger acid sites and more effective activity for catalytic alkylation of 2, 4-ditert-butylphenol wit... Mesoporous aluminosilicate with cubic ordered structure was synthesized by two-step crystallization, which showed stronger acid sites and more effective activity for catalytic alkylation of 2, 4-ditert-butylphenol with tert-butanol than conventional H-AlMCM-48 materials. 展开更多
关键词 Cubic mesostructure two-step crystallization primary structure units zeolite beta catalysis.
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Effect of RE Oxide on Impact Toughness and Primary Structure of Surfacing Metal
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作者 Yang Qingxiang Wang Airong +2 位作者 Liao Bo Yao Mei Qi Junjie 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 1998年第1期42-45,共4页
The effect of rare earth(RE) oxide on impact toughness and primary structure of surfacing metal was investigated . The results show that the impact toughness of surfacing metal containing RE oxide can be increased by ... The effect of rare earth(RE) oxide on impact toughness and primary structure of surfacing metal was investigated . The results show that the impact toughness of surfacing metal containing RE oxide can be increased by 50 %. The primary structure can be refined and its shape changed from columnar crystals to equiaxed ones. 展开更多
关键词 RE oxide impact toughness primary structure surfacing metal
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Tree structure and diversity shape the biomass of primary temperate mountain forests
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作者 Dheeraj Ralhan Ruffy Rodrigo +14 位作者 Heather Keith Annemiek Irene Stegehuis Jakob Pavlin Yumei Jiang Milos Rydval Juliana Nogueira Alexandre Fruleux Marek Svitok Martin Mikolas Daniel Kozak Martin Dusatko Pavel Janda Oleh Chaskovsky Catalin-Constantin Roibu Miroslav Svoboda 《Forest Ecosystems》 SCIE CSCD 2024年第4期568-579,共12页
Primary forests are spatially diverse terrestrial ecosystems with unique characteristics,being naturally regenerative and heterogeneous,which supports the stability of their carbon storage through the accumulation of ... Primary forests are spatially diverse terrestrial ecosystems with unique characteristics,being naturally regenerative and heterogeneous,which supports the stability of their carbon storage through the accumulation of live and dead biomass.Yet,little is known about the interactions between biomass stocks,tree genus diversity and structure across a temperate montane primary forest.Here,we investigated the relationship between tree structure(variability in basal area and tree size),genus-level diversity(abundance,tree diversity)and biomass stocks in temperate primary mountain forests across Central and Eastern Europe.We used inventory data from726 permanent sample plots from mixed beech and spruce across the Carpathian Mountains.We used nonlinear regression to analyse the spatial variability in forest biomass,structure,and genus-level diversity and how they interact with plot-level tree age,disturbances,temperature and altitude.We found that the combined effects of genus and structural indices were important for addressing the variability in biomass across different spatial scales.Local processes in disturbance regimes and uneven tree age support forest hete rogeneity and the accumulation of live and dead biomass through the natural regeneration,growth and decay of the forest ecosystem.Structural complexities in basal area index,supporte d by genus-level abundance,positively influence total biomass stocks,which was modulated by tree age and disturbances.Spruce forests showed higher tree density and basal area than mixed beech forests,though mixed beech still contributes significantly to biomass across landscapes.Forest heterogeneity was strongly influenced by complexities in forest composition(tree genus diversity,structure).We addressed the importance of primary forests as stable carbon stores,achieved through structure and diversity.Safeguarding such ecosystems is critical for ensuring the stability of the primary forest,carbon store and biodiversity into the future. 展开更多
关键词 Biodiversity indicators Biomass carbon stock Ecosystem functioning Forest composition primary forest structure Tree size distribution
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THE PRIMARY STRUCTURE OF ARROWHEAD PROTEINASE INHIBITOR
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作者 杨慧玲 朱德煦 戚正武 《Science China Chemistry》 SCIE EI CAS 1991年第9期1070-1081,共12页
After the reduction and carboxymethylation of disulfide bonds, arrowhead proteinase inhibitors A and B were cleaved either by proteinases or by cyanogen bromide, the fractionated and purified peptides were then subjec... After the reduction and carboxymethylation of disulfide bonds, arrowhead proteinase inhibitors A and B were cleaved either by proteinases or by cyanogen bromide, the fractionated and purified peptides were then subjected to sequencing by a gas phase automatic sequencer, the primary structures were completed by the alignment of the peptides sequenced with overlapping peptides. Both inhibitors A and B consist of 150 amino acid residues with three pairs of disulfide bonds, share 90% homology in structure, and are markedly different from all other Ser proteinase inhibitors so far known. Hence, the arrowhead inhibitor may belong to a new inhibitor family. Based on their structure characteristics, it was deduced that both their two reactive sites might be located in the positions of Lys-Ser (45-46) and Arg-Tyr-Lys (77-79), respectively. Among 13 mutated residues in inhibitors A and B, the substitution of residue Arg in position 87 of inhibitor B for residue Leu in A might be the main cause of leading to difference in their inhibitory activities. 展开更多
关键词 Ser proteinase inhibitor amino acid sequence ARROWHEAD primary structure reactive site
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Primary structure of p-momorcharin, a ribosome-inactivating protein from the seeds of Momordica Charantia Linn (Cucurbitaceae)
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作者 叶国杰 卢保元 +2 位作者 金善炜 钱瑞卿 汪猷 《Chinese Journal of Chemistry》 SCIE CAS CSCD 1999年第6期658-673,6,共17页
The complete amino acid sequence of β-momorcharin, a ribosome-inactivating protein from the seeds of Momordica charantia Linn (Cucurbitaceae) has been determined. This has been done by the sequence analysis of peptid... The complete amino acid sequence of β-momorcharin, a ribosome-inactivating protein from the seeds of Momordica charantia Linn (Cucurbitaceae) has been determined. This has been done by the sequence analysis of peptides obtained by enzymatic digestion with trypsin, chymotrypsin and S. aureus V8 protease, as well as by chemical cleavage with BNPS-skatole. The protein consists of 249 amino acid residues containing one asparagine - linked sugar group attached to the site of Asn 5 1 and has a calculated relative molecular mass of 28,452 Da without addition of the carbohydrate. Comparison of this sequence with those of trichosanthin and other ribosome-inactivating proteins from different species of plants shows a significant homology with each other. Regarding the similarity of their biological properties, an active domain of these proteins has been predicted here. 展开更多
关键词 Momorcharin ribosome-inactivating protein (RIP) primary structure sequence comparison
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Studies on the primary structure of chicken apolipoprotein A-I using HPLC technique
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作者 KIM.T.W. 《Chinese Journal of Chemistry》 SCIE CAS CSCD 1990年第3期251-258,共0页
The complete amino acid sequence of chicken plasma apolipoprotein(apo)A-I was determined by sequencing overlapping peptide fragments produced by trypsin,S.aureus V8 protease, and cyanogen bromide cleavage respectively... The complete amino acid sequence of chicken plasma apolipoprotein(apo)A-I was determined by sequencing overlapping peptide fragments produced by trypsin,S.aureus V8 protease, and cyanogen bromide cleavage respectively.All of the peptide fragments were purified on a Waters or on a Beckman HPLC system with a Vydae C_(18) column using 0.1% TFA in water as buffer A,and 0.08% TFA in 95% acetomtrile and 5% water as buffer B.Most of the peaks separated by these systems were pure.The partially purified fractions were subjected to rechromatography with a Hypersil ODS column using 0.005M sodium phosphate,pH 6.0,as buffer A,and 90% acetonitrile and 10% water as buffer B.The N-terminus of chicken apo A-I was determined to be aspartic acid by directly sequencing the intact protein up to 30 residues,while the C-terminus was identified as alanine by carboxypeptidase Y cleavage.There are 240 amino acid residues in mature chicken apo A-I.By direct analysis of cyanogen bromide peptide,we also determined the sequence of a 6 amino acid prosegment,which is present at approximately 10% of the molar amount of the mature protein in chicken plasma. 展开更多
关键词 Studies on the primary structure of chicken apolipoprotein A-I using HPLC technique HPLC
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A STUDY OF THE STRUCTURE AND THE EXPRESSION OF PROTOONCOGENES IN HUMAN PRIMARY GASTRIC CANCER
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作者 陈诗书 钱关祥 +10 位作者 陈季 王敦瑞 章有章 孔良曼 赵涵芳 何尧祥 汪肖钢 薛建静 钱晓岚 于丽莉 王璐 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 1990年第1期4-11,共8页
The allelic distribution of EcoRI and BamHI fragments of ras family genes between the human primary gastric cancer tissues and the corresponding adjacent normal tissues did not show any differences. Three genotypes of... The allelic distribution of EcoRI and BamHI fragments of ras family genes between the human primary gastric cancer tissues and the corresponding adjacent normal tissues did not show any differences. Three genotypes of BamHI restriction fragments length polymorphism of c-H-ras were revealed. No significant differences in the RFLPs were observed between normal individuals and gastric cancer patients. Four protooncogenes, c-H-ras, N-ras, c-myc and c-fos, were found to be transcriptionally active in the gastric cancer tissues in some cases examined. The comparison of the expression of these oncogenes between the malignant tissues and the corresponding normal tissues showed differential patterns. The expression of c-H-ras at cellular level was detected with in situ hybridization. The enhanced expression of c-H-ras in the gastric cancer cells was demonstrated, but the degree of the expession among the cancer cells was shown to be heterogeneous. In addition, the enhanced expression of c-H-ras was seen in the inflammatory cells. 展开更多
关键词 A STUDY OF THE structure AND THE EXPRESSION OF PROTOONCOGENES IN HUMAN primary GASTRIC CANCER EcoRI rRNA BamHI DNA
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Study of quantum well mixing induced by impurity-free vacancy in the primary epitaxial wafers of a 915 nm semiconductor laser
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作者 Tianjiang He Suping Liu +5 位作者 Wei Li Li Zhong Xiaoyu Ma Cong Xiong Nan Lin Zhennuo Wang 《Journal of Semiconductors》 EI CAS CSCD 2023年第10期70-76,共7页
Output power and reliability are the most important characteristic parameters of semiconductor lasers.However,catas-trophic optical damage(COD),which usually occurs on the cavity surface,will seriously damage the furt... Output power and reliability are the most important characteristic parameters of semiconductor lasers.However,catas-trophic optical damage(COD),which usually occurs on the cavity surface,will seriously damage the further improvement of the output power and affect the reliability.To improve the anti-optical disaster ability of the cavity surface,a non-absorption window(NAW)is adopted for the 915 nm InGaAsP/GaAsP single-quantum well semiconductor laser using quantum well mix-ing(QWI)induced by impurity-free vacancy.Both the principle and the process of point defect diffusion are described in detail in this paper.We also studied the effects of annealing temperature,annealing time,and the thickness of SiO_(2) film on the quan-tum well mixing in a semiconductor laser with a primary epitaxial structure,which is distinct from the previous structures.We found that when compared with the complete epitaxial structure,the blue shift of the semiconductor laser with the primary epi-taxial structure is larger under the same conditions.To obtain the appropriate blue shift window,the primary epitaxial struc-ture can use a lower annealing temperature and shorter annealing time.In addition,the process is less expensive.We also pro-vide references for upcoming device fabrication. 展开更多
关键词 catastrophic optical damage primary epitaxial structure impurity-free vacancy disordering quantum well intermixing non-absorption window
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A novel plant defensin from Chinese mistletoe,Viscum coloratum (Kom.) Nakai 被引量:1
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作者 Shi Lei Liu Xiu Bao Du Jing Lin Kong Hui Jiang 《Chinese Chemical Letters》 SCIE CAS CSCD 2007年第1期55-58,共4页
A novel polypeptide named as defensin CM was isolated from Chinese mistletoe, Viscum coloratura (Kom.) Nakai. The amino acid sequence was determined by the combination of Edman degradation, endoproteinase Lys-C dige... A novel polypeptide named as defensin CM was isolated from Chinese mistletoe, Viscum coloratura (Kom.) Nakai. The amino acid sequence was determined by the combination of Edman degradation, endoproteinase Lys-C digestion, and MALDI-TOF mass spectrometry. The primary structure was ATCSAPSGRF KGACFSSNTC SNICKTLEGL KDGHCTGLAC YCSRNC. 展开更多
关键词 Viscum coloratura MISTLETOE primary structure Plant defensin POLYPEPTIDE
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New Polypeptides from Chinese Mistletoe, Viscum coloratum (Kom.) Nakai
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作者 Shi Lei LIU Xiu Bao DU Jing Lin KONG 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第1期41-44,共4页
Three viscotoxins have been isolated from Chinese mistletoe, Viscum coloratura (Kom.) Nakai. The primary structures were determined unambiguously by the combination of Edman degradation, endoproteinase Elu-c digesti... Three viscotoxins have been isolated from Chinese mistletoe, Viscum coloratura (Kom.) Nakai. The primary structures were determined unambiguously by the combination of Edman degradation, endoproteinase Elu-c digestion, and Q-TOF mass spectrometry. One was identified as viscotoxin C1, which was for the first time isolated from Chinese mistletoe. The other two were new polypeptides, named as viscotoxin B5 and viscotoxin B8. Pharmacological studies showed that the polypeptides exhibit distinct cytotoxicity to human cancer cells. 展开更多
关键词 Viscum coloratura MISTLETOE ISOLATION primary structure viscotoxin.
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Primary Structural Characterization of Phospholipid Hydroperoxide Glutathione Peroxidase
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作者 王泽斌 杨晓东 +1 位作者 赵南明 刘进元 《Tsinghua Science and Technology》 SCIE EI CAS 2002年第4期363-368,共6页
More than 20 sequences of phospholipid hydroperoxide glutathione peroxidase (PHGPX) from a sequence database were analyzed. The analyses show that the primary structures of most PHGPX proteins have three highly con... More than 20 sequences of phospholipid hydroperoxide glutathione peroxidase (PHGPX) from a sequence database were analyzed. The analyses show that the primary structures of most PHGPX proteins have three highly conserved regions forming a catalytic center and have more than 50% amino acid sequence identity in common. However, two PHGPXs from bovine and swine with the same function have very low similarity with typical PHGPXs and do not have the three highly conserved regions. Thus, the PHGPX proteins are divided into two types: those with the three highly conserved regions, designated as PHGPX I, and the others as PHGPX II. In general, type I proteins are composed of ca.170 amino acid residues; a few of them have an extra signal peptide sequence at the N terminal of the protein. The composition of plant and animal PHGPX amino acids is very different, with most plant PHGPXs being weak acidic, while most animal ones are alkaline. Another specific conservative motif is also found in plant PHGPX proteins. System evolution analysis shows that ortholog and paralog evolution models both exist in PHGPXs, with the plant PHGPX and the animal PHGPX diverging exclusively into two branches in PHGPX I. The information revealed by the evolution tree agrees with the general species evolution process from low to advanced and from simple to complicated. 展开更多
关键词 phospholipid hydroperoxide glutathione peroxidase (PHGPX) isoelectric point and transmembrane region molecular evolution primary structural characterization
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