全文获取类型
收费全文 | 3233篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
化学工业 | 21篇 |
金属工艺 | 5篇 |
建筑科学 | 2篇 |
矿业工程 | 2篇 |
能源动力 | 4篇 |
轻工业 | 8篇 |
水利工程 | 1篇 |
无线电 | 3篇 |
一般工业技术 | 10篇 |
冶金工业 | 3169篇 |
原子能技术 | 1篇 |
自动化技术 | 9篇 |
出版年
2022年 | 3篇 |
2020年 | 3篇 |
2018年 | 5篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2011年 | 2篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2008年 | 1篇 |
2007年 | 1篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 6篇 |
2003年 | 4篇 |
1999年 | 70篇 |
1998年 | 924篇 |
1997年 | 540篇 |
1996年 | 391篇 |
1995年 | 235篇 |
1994年 | 162篇 |
1993年 | 183篇 |
1992年 | 20篇 |
1991年 | 33篇 |
1990年 | 27篇 |
1989年 | 29篇 |
1988年 | 24篇 |
1987年 | 19篇 |
1986年 | 18篇 |
1985年 | 19篇 |
1983年 | 5篇 |
1982年 | 19篇 |
1981年 | 25篇 |
1980年 | 33篇 |
1979年 | 3篇 |
1978年 | 10篇 |
1977年 | 131篇 |
1976年 | 258篇 |
1975年 | 9篇 |
1973年 | 1篇 |
1965年 | 1篇 |
1964年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有3235条查询结果,搜索用时 109 毫秒
931.
932.
TV Konchugova VA Vinogradov AA Minenkov AS Bobkova SB Pershin 《Canadian Metallurgical Quarterly》1993,115(4):391-393
The aim of the present paper was to study the effect of infrared laser radiation on endocrine regulation of immunogenesis and on endogenic opioid system. For this purpose experiments on rabbits were carried out. The animals underwent transcerebral radiation with subsequent induction of the primary immune response (PIR) to thymus-dependent antigen (sheep red blood cells). The PIR suppression was revealed in all test animals. It was more graphically expressed in rabbits exposed to impulse radiation. Immunodepression was combined with the increase of glucocorticoid activity of adrenal cortex, while no significant changes in thyroid hormones were registered. The 0.08 Joles impulse radiation cause a palpable fall in opioid concentration in blood plasma, the fact, which can be possibly accounted for the rapid exhaustion of opioid synthesis after their stimulation due to laser radiation. 相似文献
933.
934.
AS O'Marcaigh WL Nichols NL Hassinger JD Mullins AA Mallouh GS Gilchrist WG Owen 《Canadian Metallurgical Quarterly》1996,88(7):2611-2618
The structural abnormalities and functional characteristics of dysfunctional prothrombin variants in two new kindreds have been determined. Prothrombin Corpus Christi (family 1) was purified and found to have markedly reduced fibrinogen clotting activity, yet normal amidolytic and near-normal platelet aggregating activity. A transition (C to T) at nucleotide position 8885, present in the heterozygous form in affected family members, resulted in the substitution of Cys for Arg 382. This substitution results in the loss of a positive charge within the fibrinogen-binding exosite of thrombin, thus accounting for the observed functional defect. A heterozygous C to T transition was also present at position 19994 in other family members with a hypoprothrombinemic phenotype. This mutation results in the replacement of Gln 541 (CAA) by a premature stop codon (TAA). Prothrombin Dhahran (family 2) was found to have markedly reduced fibrinogen clotting activity, but normal amidolytic activity. Affected family members were found to have a G to A transition at nucleotide position 7312 resulting in the substitution of His for Arg 271. This substitution results in the abolition of a factor Xa cleavage site, yielding meizothrombin rather than thrombin, on activation of prothrombin Dhahran by factor Xa. All but one of the above mutations occur at CpG dinucleotides, thus further supporting the observation of a high incidence of CpG transitions in hereditary dysprothrombinemia. The significant bleeding tendencies of individuals homozygous for prothrombin Dhahran (prothrombin clotting activity 5% to 7%) contrast sharply with the absence of significant chronic bleeding in the proband expressing prothrombin Corpus Christi (prothrombin clotting activity 2%). Our findings underscore the capacity of thrombin to contribute to clinical hemostasis by mechanisms other than its fibrinogen clotting activity. 相似文献
935.
936.
937.
938.
In order to clarify the influence of inflammatory mediators of the arachidonic acid cascade in the mechanism of nasal polyp growth, peptido-leukotriene (pLT), prostaglandin E2 (PGE2) and thromboxane B2 (TXB2) synthesis was investigated. In addition to several stimuli, functionally intact human biopsy specimens of polypous and normal tissue were incubated. Especially remarkable was the significantly increased release of pLT by polypous tissue upon arachidonic acid stimulation, in contrast to only slightly elevated PGE2 release compared to normal tissue. Basic release of pLT and PGE2 was similar for polypous and normal tissue. Examining TXB2 release, no significant difference was observed with regard to the origin of tissues. These data support an altered pattern of the lipoxygenase and cyclo-oxygenase pathways when tissue becomes irritated and suggest their involvement in the aetiopathogenesis of nasal polyps. 相似文献
939.
MF Abdul-Mohsen A al-Quorain AA al-Hamdan A Husain H Qutub GO Ladipo 《Canadian Metallurgical Quarterly》1993,70(12):777-781
Concern has been expressed about the cost-effectiveness of the Coronary Care Unit (CCU) and solution options offered on account of the large number of patients admitted to the CCU who turn out not to have acute myocardial infarction. In a prospective study over four years, we studied a group of patients admitted to the CCU with suspected myocardial infarction but who did not have diagnostic ECG and/or enzyme changes for the causes of their chest pain. We compared the clinical profile of these patients (Group A) with that of a random sample of patients with confirmed myocardial infarction (Group B). Gastrointestinal disorders, musculoskeletal chest pain, panic and anxiety disorders were the major causes of chest pain in Group A patients. A normal ECG and a normal creatine phosphokinase (CPK) within the first 24 hours, a normal initial random blood sugar, a younger age and absence of coronary risk factors effectively separated Group A patients as low risk from Group B patients as high risk for acute myocardial infarction. These simple parameters will assist physicians providing CCU care in most hospitals in early decision making and in the judicious use of the CCU. 相似文献
940.
DC Jette FT Kreutz BA Malcolm DS Wishart AA Noujaim MR Suresh 《Canadian Metallurgical Quarterly》1996,42(12):1961-1969
Prostate-specific antigen (PSA) is a widely used marker for screening and monitoring prostate cancer. We identified and characterized the epitopes of two anti-PSA monoclonal antibodies (mAbs) designated B80 and B87. The epitopes were initially mapped as nonoverlapping by developing a sandwich immunoassay to measure PSA with the two anti-PSA mAbs. The two antibodies do not cross-react with homologous pancreatic kallikrein, but recognize epitopes unique to PSA. B80 and B87 can recognize both free and complexed PSA and hence measure total PSA. Epitope scanning and bacteriophage peptide library affinity selection procedures were used to identify and locate an epitope on PSA. A possible epitope for B80 was identified as being located on or near PSA amino acid residues 50-58 (-GRH-SLFHP-). The epitope for B87 was likely on an exposed nonlinear conformational determinant, unique to PSA, and not masked by the binding of B80 or alpha 1-antichymotrypsin. 相似文献