全文获取类型
收费全文 | 1043篇 |
免费 | 4篇 |
国内免费 | 1篇 |
专业分类
化学工业 | 9篇 |
金属工艺 | 11篇 |
机械仪表 | 2篇 |
建筑科学 | 7篇 |
矿业工程 | 5篇 |
轻工业 | 19篇 |
石油天然气 | 5篇 |
无线电 | 15篇 |
一般工业技术 | 15篇 |
冶金工业 | 946篇 |
原子能技术 | 4篇 |
自动化技术 | 10篇 |
出版年
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 5篇 |
2012年 | 4篇 |
2011年 | 7篇 |
2010年 | 7篇 |
2009年 | 9篇 |
2008年 | 12篇 |
2007年 | 10篇 |
2006年 | 5篇 |
2005年 | 11篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 25篇 |
1998年 | 253篇 |
1997年 | 157篇 |
1996年 | 100篇 |
1995年 | 56篇 |
1994年 | 37篇 |
1993年 | 51篇 |
1992年 | 6篇 |
1991年 | 11篇 |
1990年 | 5篇 |
1989年 | 12篇 |
1988年 | 14篇 |
1987年 | 6篇 |
1986年 | 12篇 |
1985年 | 18篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 10篇 |
1981年 | 12篇 |
1980年 | 10篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 28篇 |
1976年 | 91篇 |
1975年 | 2篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1970年 | 3篇 |
1969年 | 2篇 |
1968年 | 2篇 |
1955年 | 2篇 |
1940年 | 1篇 |
排序方式: 共有1048条查询结果,搜索用时 15 毫秒
21.
AIM: To examine the association of Epstein-Barr virus (EBV) with carcinoma of the ear. METHODS: Five non-keratinising squamous cell carcinomas and two undifferentiated carcinomas of the ear were examined. In situ hybridisation was used to localised EBV-encoded RNAs (EBER). Immunohistochemical methods to detect LMP-1 and EBNA2 were performed in the EBER positive cases. RESULTS: Two cases were EBER positive, including one non-keratinising and one undifferentiated carcinoma. Both showed identical morphology to those arising from the nasopharynx, with abundant lymphoid stroma. They were both negative for LMP-1 and EBNA2. CONCLUSIONS: EBV associated carcinoma with the morphology of lymphoepithelioma can also arise from the middle ear. 相似文献
22.
M Patel RF Kaltenbach DA Nugiel RJ McHugh PK Jadhav LT Bacheler BC Cordova RM Klabe S Erickson-Viitanen S Garber C Reid SP Seitz 《Canadian Metallurgical Quarterly》1998,8(9):1077-1082
Cyclic urea SD146, a potent HIV protease inhibitor bearing a flat resistance profile, possessed poor solubility and bioavailability, which precluded further development of the compound. In an effort to improve upon the pharmacokinetic profile of the compound, several analogs modified at the P1/P1' residues were prepared and evaluated. Several of those compounds displayed significant improvement of physical properties. 相似文献
23.
扫描笔是近年新兴的扫描产品,它又可以称为微型扫描仪或手刮式扫描笔,常见的扫描笔大小大约跟"折扇"差不多,甚者会更小。它最大的特点是携带方便,特别适合商务人士随身携带出差办公使用。一般购买它主要是用于扫描办公文件、身份证、名片或大型工程图等等。下面,小编带大家去深入了解扫描笔,让你能够知才善用。 相似文献
24.
Molecular cloning, expression, and characterization of a functional single-chain Fv antibody to the mycotoxin zearalenone 总被引:1,自引:0,他引:1
Q Yuan JR Clarke HR Zhou JE Linz JJ Pestka LP Hart 《Canadian Metallurgical Quarterly》1997,63(1):263-269
The heavy-chain and kappa light-chain variable region genes of an antizearalenone hybridoma cell line (2G3-6E3-2E2) were isolated by PCR and joined by a DNA linker encoding peptide (Gly4Ser)3 as a single-chain Fv (scFv) DNA fragment. The scFv DNA fragment was cloned into a phagemid (pCANTAB5E) and expressed as a fusion protein with E tag and phage M13 p3 in Escherichia coli TG1. In the presence of helper phage M13K07, the scFv fusion protein was displayed on the surfaces of recombinant phages. High-affinity scFv phages were enriched through affinity selection in microtiter wells coated with zearalenone-ovalbumin conjugate. The selected recombinant phages were used to infect E. coli HB2151 for the production of soluble scFv antibodies. One selected clone (pQY1.5) in HB2151 secreted a soluble scFv antibody (QY1.5) with a high zearalenone-binding affinity (concentration required for 50% inhibition of binding, 14 ng/ml), similar to that of parent monoclonal antibody in a competitive indirect enzyme-linked immunosorbent assay. However, scFv QY1.5 exhibited higher cross-reactivity with zearalenone analogs and had greater sensitivity to methanol destabilization than the parent monoclonal antibody did. Nucleotide sequence analyses revealed that the light-chain portion of scFv QY1.5 had a nucleotide sequence identity of 97% to a mouse germ line gene VK23.32 in mouse kappa light-chain variable region subgroup V, whereas the heavy-chain nucleotide sequence was classified as mouse heavy-chain subgroup III (D) but without any closely related members having highly homologous complementarity-determining region sequences. The potential of soluble scFv QY1.5 for routine screening of zearalenone and its analogs was demonstrated with zearalenone-spiked corn extracts. 相似文献
25.
E. A. Garber S. I. Pavlov I. A. Kozhevnikova M. A. Timofeeva V. V. Kuznetsov 《Steel in Translation》2011,41(4):332-337
Surface defects of cold-rolled sheet in the form of transverse ribbing and cold-hardening bands are due to vibration in the working cells of the continuous rolling mill. The vibration is excited by impact of the working-roller supports on the frame’s supporting plane during reverse motion within the available gap. Means of eliminating these defects are developed on the basis of new approaches to cold-rolling theory. 相似文献
26.
Shari Sellers Walter Horodnik Aileen House Jennifer Wylie Peter Mauser Natalie Garber 《Drug development and industrial pharmacy》2015,41(12):1989-1996
AbstractContext: Aerosol delivery to animals in preclinical settings has historically been very challenging, requiring the use of techniques, such as intratracheal instillation and dry powder insufflation, that are somewhat invasive, inefficient and not representative of clinical inhalation.Objective: The objective of this work is to develop a system to deliver dry powder to dogs in an efficient and effective manner for the study of new anti-migraine compounds in development.Materials and methods: The new device uses a metered aliquot of a dry gas to force dry powder drug from a pre-filled HPMC capsule into an AeroChamber® spacer for subsequent inhalation by the animal.Results: The delivery of two invesigational migraine drugs via the new device was assessed in vitro using abbreviated Andersen cascade impaction and showed the device is capable of generating a reproducible delivered dose of up to ~68% with more than 50% of the dose in the respirable range. In vivo studies have also been performed showing that this device effectively delivered the migraine drugs to spontaneously breathing dogs using a proprietary validated dog inhalation model.Discussion: Results confirmed that the air pressurized capsule device (APCD) was effective in delivering the APIs to lungs of the animals. The in vivo data verified the advantages of inhaled delivery over oral delivery for this class of drugs and were used to establish the cardiopulmonary and respiratory side effect liability profile for these compounds.Conclusions: This work has demonstrated the utility of this device for quick and accurate screening of prospective drug candidates, representing a significant improvement in ease of use and reprodicibility over current delivery methods. 相似文献
27.
28.
In order to study the prevalence and the clinical features of renal tuberculosis associated with AIDS, we studied the renal tissue of the necropsies made in 46 AIDS patients under light microscopy. We found renal tuberculous granuloma in 11 (23%) patients (in 3 without previous diagnosis of renal or extrarenal tuberculosis) and only 4 of them presented moderate hematuria or pyuria sterile. As subclinical renal tuberculosis was frequent in this group of AIDS patients, the urine culture for Mycobacterium tuberculosis may be useful for diagnosing tuberculosis in AIDS patients. 相似文献
29.
30.
IV Ga?voronski? LP Tikhonova SV Chepur GI Nichiporuk 《Canadian Metallurgical Quarterly》1997,112(6):33-37
An original quantitative examination of oxidation-reduction enzymes activity in endotheliocytes of hemomicroclrculatory vessels of jejunum and rectum submucosal base in normal state and in portal hypertension was performed by the authors. Comparative analysis of the activity of the enzymes studied revealed different metabolic processes intensity in these organs, dependent on current hemodynamic conditions. Cytochemical changes in hemomicrocirculatory bed are consistent with structural reorganizations that arise in the wall of vessels studied, consist of several phases and may be used as an assessment criterion for defining the portal hypertension stage. 相似文献