检索结果-南通市图书馆

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

设计定向井和水平井的简化方程

钻井工艺情报 1991年第3期 1-10页

作者： wigg.,ml 宿连秀

Ice Induced Low Temperature Fatigue Crack Propagation in Offshore Structural Steel A131

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China Ocean Engineering 1998年第3期13卷 275-284页

作者： Duan, ml Gao, ZJ Liu, CT China Classificat Soc Beijing 100006 Peoples R China Chinese Acad Sci Inst Mech Beijing 100080 Peoples R China

To investigate the low temperature fatigue crack propagation behavior of offshore structural steel A131 under random ice loading, three ice failure modes that are commonly present in the Bohai Gulf are simulated according to the vibration stress responses induced by real ice loading. The test data are processed by a universal software FCPUSL developed on the basis of the theory of fatigue crack propagation and statistics. The fundamental parameter controlling the fatigue crack propagation induced by random ice loading is determined to be the amplitude root mean square stress intensity factor K-arm. The test results are presented on the crack propagation diagram where the crack growth rate da/dN is described as the function of K-arm. It is evident that the ice failure modes have great influence on the fatigue crack propagation behavior of the steel in ice-induced vibration. However, some of the experimental phenomena and test results are hard to be physically explained at present. The work in this paper is an initial attempt to investigate the cause of collapse of offshore structures due to ice loading.

关键词： low temperature fatigue crack propagation offshore structure steel A131 ice load random vibration

Molecular Weight Characterization of Partially Hydrolyzed Polyacrylamide in the Complex Salts Solution

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1997年第1期8卷 73-74页

作者： Ye, ml Han, D Shi, LH ACAD SINICA INST CHEMPOLYMER PHYS LABBEIJING 100080PEOPLES R CHINA

The effects of the nature of salts, salt concentration, pH value, degree of hydrolysis as well as surfactant on molecular size of HPAM were studied. It is found that [eta] of HPAM changes with all the above variables, and the molecular weight of HPAM can be obtained through [eta] measurement at a specific salts environment in which the [eta] is independent of above factors.

关键词： Molecular Weight Characterization of Partially Hydrolyzed Polyacrylamide in the Complex Salts Solution

A New Triterpenoid Saponin from Aralia subcapitata

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2000年第10期11卷 913-914页

作者： Zou, ml Sang, SM Xia, ZH Lao, AN Chinese Acad Sci Shanghai Inst Mat Med Shanghai 200031 Peoples R China

A new oleanane-type saponin, named subcapitatoside A, has been isolated from the roots of Aralia subcapitata. On the basis of chemical and spectral evidence: the structure of subcapitatoside A has been established as:... 详细信息

关键词： Aralia subcapitat oleanane-type saponin subcapitatoside A

Isolation of osRACD gene encoding a small GTP-binding protein from rice

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2002年第20期47卷 1673-1679页

作者： ml Zhiyong WANG Shusheng WU Naihu Institute of Developmental Biology Chinese Academy of SciencesBeijing 100080China Academy of Life Sciences Peking UniversityBeijing 100871China

Using an improved version of mRNA differential display technology, we have obtained a differentially displayed fragment RDP-8. Homologous comparison indicated that the fragment RDP-8 has high homology with the gene encoding maize small GTP-binding protein. By screening cDNA library of the rice Nongken 58N panicle using the newly obtained fragment RDP-8 as probe, we further found the full-length cDNA of osRACD gene that encodes a rice small GTP-binding protein. As compared with maize RACD gene, the osRACD of rice shows remarkable homology in both nucleotide sequence and amino acid sequence, 88% and 97% respectively. Evidence from RT-PCR study indicates that osRACD gene is related to photoperiod fertility conversion of photoperiod sensitive genie male sterility (PSGMS) rice.

关键词： rice osRACD mRNA differential display light signal transduction.

Broadband antireflection coatings deposited by magnetron sputtering

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第19期42卷 1612-1615页

作者： Wang, ml Gong, H Fan, ZX Optical Coating Center Shanghai Institute of Optic and Fine Machine Chinese Academy of Sciences Shanghai China

IN 1938, antireflection coatings were prepared by Americans. Later, they were successfullygot by Europeans. The antireflection coatings are very important in optical films, and used inmost optical instruments such as photograph eyes, glasses, telescopes and microscopes. Atpresent, the technology of preparing antireflection is perfect. Especially, with the help ofcomputer, multi-antireflection coating can be constructed easily. Resistance heating

关键词： magnetron sputtering broadband antireflection deposition.

An approach to noble-gas isotopic compositions in natural gases and gas-source tracing in the Ordos Basin,China

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2002年第6期47卷 489-493页

作者： Liu, WH Sun, ml Xu, YC Chinese Acad Sci Lanzhou Inst Geol State Key Lab Gas Geochem Lanzhou 730000 Peoples R China

Isotopic compositions of noble gases, i.e. He Ar Kr and Xe, are measured in natural gases from the Zhongbu gasfield in the Ordos Basin. And heavy noble-gas isotopes (Kr, Xe) are here first used in geochemically studying natural gases and gas-source correlation. Isotopic compositions of heavy noble gases in natural gases, especially Xe, show two-source mixing in the Zhongbu gasfield. Gas sources are somewhat different in the northeast and the southwest of the gasfield. Generally, the gas source of the Lower Paleozoic makes a greater contribution in the southwest than in the northeast in the field. Two kinds of gases can be differentiated from isotopic compositions of heavy noble gases and from their relation with the Ar isotopic composition. Therefore, the comprehensive study on isotopic compositions of light and heavy noble gases can supply more useful information on gas-source correlation and tracing.

关键词： noble gas Kr Xe isotope natural gas gas-source corre-lation.