全文获取类型
收费全文 | 9556篇 |
免费 | 106篇 |
国内免费 | 9篇 |
专业分类
电工技术 | 98篇 |
综合类 | 2篇 |
化学工业 | 1011篇 |
金属工艺 | 101篇 |
机械仪表 | 300篇 |
建筑科学 | 219篇 |
矿业工程 | 28篇 |
能源动力 | 129篇 |
轻工业 | 872篇 |
水利工程 | 107篇 |
石油天然气 | 16篇 |
无线电 | 863篇 |
一般工业技术 | 1020篇 |
冶金工业 | 4050篇 |
原子能技术 | 108篇 |
自动化技术 | 747篇 |
出版年
2021年 | 68篇 |
2020年 | 51篇 |
2019年 | 61篇 |
2018年 | 60篇 |
2017年 | 82篇 |
2016年 | 65篇 |
2015年 | 47篇 |
2014年 | 104篇 |
2013年 | 315篇 |
2012年 | 161篇 |
2011年 | 238篇 |
2010年 | 212篇 |
2009年 | 231篇 |
2008年 | 260篇 |
2007年 | 240篇 |
2006年 | 245篇 |
2005年 | 218篇 |
2004年 | 178篇 |
2003年 | 200篇 |
2002年 | 200篇 |
2001年 | 162篇 |
2000年 | 161篇 |
1999年 | 220篇 |
1998年 | 1002篇 |
1997年 | 632篇 |
1996年 | 514篇 |
1995年 | 353篇 |
1994年 | 303篇 |
1993年 | 305篇 |
1992年 | 116篇 |
1991年 | 151篇 |
1990年 | 147篇 |
1989年 | 152篇 |
1988年 | 145篇 |
1987年 | 146篇 |
1986年 | 118篇 |
1985年 | 141篇 |
1984年 | 94篇 |
1983年 | 102篇 |
1982年 | 73篇 |
1981年 | 96篇 |
1980年 | 81篇 |
1979年 | 79篇 |
1978年 | 74篇 |
1977年 | 138篇 |
1976年 | 278篇 |
1975年 | 75篇 |
1974年 | 71篇 |
1973年 | 63篇 |
1972年 | 54篇 |
排序方式: 共有9671条查询结果,搜索用时 15 毫秒
111.
KG Davey AD Holmes EM Johnson A Szekely DW Warnock 《Canadian Metallurgical Quarterly》1998,36(4):926-930
The FUNGITEST method (Sanofi Diagnostics Pasteur, Paris, France) is a microplate-based procedure for the breakpoint testing of six antifungal agents (amphotericin B, flucytosine, fluconazole, itraconazole, ketoconazole, and miconazole). We compared the FUNGITEST method with a broth microdilution test, performed according to National Committee for Clinical Laboratory Standards document M27-A guidelines, for determining the in vitro susceptibilities of 180 isolates of Candida spp. (50 C. albicans, 50 C. glabrata, 10 C. kefyr, 20 C. krusei, 10 C. lusitaniae, 20 C. parapsilosis, and 20 C. tropicalis isolates) and 20 isolates of Cryptococcus neoformans. Overall, there was 100% agreement between the methods for amphotericin B, 95% agreement for flucytosine, 84% agreement for miconazole, 83% agreement for itraconazole, 77% agreement for ketoconazole, and 76% agreement for fluconazole. The overall agreement between the methods exceeded 80% for all species tested with the exception of C. glabrata (71% agreement). The poorest agreement between the results for individual agents was seen with C. glabrata (38% for fluconazole, 44% for ketoconazole, and 56% for itraconazole) and C. tropicalis (50% for miconazole). The FUNGITEST method misclassified as susceptible 2 of 12 (16.6%) fluconazole-resistant isolates, 2 of 10 (20%) itraconazole-resistant isolates, and 4 of 8 (50%) ketoconazole-resistant isolates of several Candida spp. Further development of the FUNGITEST procedure will be required before it can be recommended as an alternative method for the susceptibility testing of Candida spp. or C. neoformans. 相似文献
112.
WL Olszewski 《Canadian Metallurgical Quarterly》1996,29(3):126-131
Dermatolymphangioadenitis (DLA) is a common and serious complication of obstructive peripheral lymphedema. The clinical characteristics of acute DLA are local tenderness and erythema of the skin, sometimes red streaks along the distribution of the superficial lymphatics and enlarged inguinal lymph nodes. Systemic symptoms include malaise, fever and chills. In its subacute or latent form, only skin involvement is observed. Each episode of DLA is commonly followed by worsening of leg swelling. Numerous clinical studies suggest that administration of antibiotic drugs interrupt the acute episodes and prevent their recurrence. We investigated the clinical course of lymphedema with respect to the prevalence of DLA in patients receiving injections of long-acting penicillin (benzathine penicillin). Forty-five randomly selected patients with obstructive lymphedema of the lower limbs were included in an open clinical trial. The inclusion criteria was stage II-IV lymphedema of postsurgical, posttraumatic, and postdermatitis type with at least 3 previous episodes of DLA. Benzathine penicillin (PCN) was given after the last presenting episode of DLA in a dose of 1,200,000 u, intramuscularly at 3-week intervals, for at least one year. Each patient was reevaluated at 3-month intervals. They were instructed in early diagnosis of DLA and reported promptly to the responsible senior surgeon with prodrome symptoms of recurrent DLA. The duration of lymphedema before initiation of therapy was 7 months to 40 years and the frequency of DLA was 1-6 episodes per year. PCN administration lasted for at least one year but was extended in all patients because of the tendency for recurrence of DLA after cessation of PCN injections. In 26 of these patients, PCN administration extended to over 5 years and in 2 over 10 years. Recurrent episodes of DLA occurred in the PCN-treated group during one year follow-up in only 4 of the 45 patients (9%). The frequency episodes in 3 patients with recurrent DLA was 1-2/year; in one patient, no positive effect of PCN therapy was observed. There were no apparent side effects of long-term PCN therapy. These data, although evaluated without a placebo group, suggest that long-term PCN administration decreases the frequency of DLA attacks and furthermore provide justification for carrying out a double-blind randomly placebo-controlled clinical trial of the efficacy of prophylactic antibiotic drug treatment in forestalling DLA episodes. 相似文献
113.
JW Finley PE Johnson PG Reeves RA Vanderpool M Briske-Anderson 《Canadian Metallurgical Quarterly》1994,42(2):81-96
Biliary/pancreatic (B/P) secretions are a major component of endogenous secretions, and endogenously secreted Zn is a primary means of Zn homeostasis. This study examined whether B/P fluid alters the absorption/reabsorption of Zn and, in doing so, whether this contributes to homeostatic control of Zn. Animal experiments utilized rats fed 10 or 300 micrograms Zn/kg diet. An open-ended gut perfusion study in which 65Zn-labeled B/P fluid or 67Zn-labeled and digested diet found significantly decreased Zn absorption from B/P fluid. Although Zn absorption from both sources was less in animals fed diets higher in Zn, there was no interaction of treatment and diet. Further studies utilizing cultured human colon carcinoma cells (CACO-2) as in vitro models of gut enterocytes found that the presence of B/P fluid significantly decreased Zn retention and/or transport and resulted in a redistribution of cellular Zn after 1200 min of incubation. These studies show that a substance in B/P fluid can decrease the absorption of Zn and also suggest that dietary Zn and Zn associated with B/P secretions are absorbed from distinct pools. However, the lack of an interactive effect with diet, and the amount of time required to see differences in CACO-2 cells, suggest that differences in absorption are not a major contributor to Zn homeostasis. 相似文献
114.
Johnson CR 《Computing in science & engineering》2012,14(1):12-21
Advances in computational geometric modeling, imaging, and simulation let researchers build and test models of increasing complexity, generating unprecedented amounts of data. As recent research in biomedical applications illustrates, visualization will be critical in making this vast amount of data usable; it's also fundamental to understanding models of complex phenomena. 相似文献
115.
Future directions and research issues for ergonomics and advanced manufacturing technology (AMT) 总被引:1,自引:0,他引:1
In recent years, great progress has been made in the development of computer-based technologies that support the manufacturing industries. Those concerned with advanced manufacturing technology (AMT) are becoming increasingly aware of the fundamental importance of human organisational issues for the successful development, implementation, operation and maintenance of AMT. The discipline of industrial ergonomics and occupational occupational psychology, therefore, have a significant contribution to make in this field. This paper introduces the special issue, Ergonomics Matters in AMT, and presents a discussion of some of the future directions of AMT and the likely implications for ergonomics research. 相似文献
116.
Hunter S Howard M Marki P Gelpi MJ Francone J Reed G McGinty K Mayes B Ysmael R Johnson C 《Food management》1992,27(1):92-5, 98
Consumer confidence is at its lowest ebb since 1980. Economic growth is at a standstill & unemployment & inflation are both rising. Here's a front-line report from more than three dozen operators who are fending off the recession's dual pressures of slow sales & rising costs. They are using discount pricing, partnering with vendors, setting pay for performance standards & a variety of other recession-beating practices. 相似文献
117.
118.
119.
120.