全文获取类型
收费全文 | 467篇 |
免费 | 12篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 7篇 |
综合类 | 1篇 |
化学工业 | 106篇 |
金属工艺 | 6篇 |
机械仪表 | 14篇 |
建筑科学 | 16篇 |
矿业工程 | 1篇 |
能源动力 | 5篇 |
轻工业 | 27篇 |
水利工程 | 9篇 |
无线电 | 48篇 |
一般工业技术 | 71篇 |
冶金工业 | 102篇 |
原子能技术 | 5篇 |
自动化技术 | 62篇 |
出版年
2023年 | 3篇 |
2022年 | 21篇 |
2021年 | 28篇 |
2020年 | 3篇 |
2019年 | 10篇 |
2018年 | 7篇 |
2017年 | 5篇 |
2016年 | 13篇 |
2015年 | 10篇 |
2014年 | 19篇 |
2013年 | 18篇 |
2012年 | 16篇 |
2011年 | 21篇 |
2010年 | 13篇 |
2009年 | 20篇 |
2008年 | 16篇 |
2007年 | 18篇 |
2006年 | 17篇 |
2005年 | 11篇 |
2004年 | 17篇 |
2003年 | 11篇 |
2002年 | 11篇 |
2001年 | 7篇 |
2000年 | 4篇 |
1999年 | 9篇 |
1998年 | 38篇 |
1997年 | 14篇 |
1996年 | 9篇 |
1995年 | 14篇 |
1994年 | 8篇 |
1993年 | 8篇 |
1992年 | 10篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1985年 | 1篇 |
1984年 | 6篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1972年 | 2篇 |
1971年 | 3篇 |
排序方式: 共有480条查询结果,搜索用时 15 毫秒
51.
J. Fodor K. Meyer M. Riedlberger J. Bauer P. Horn F. Kovacs M. Kovacs 《Food Additives & Contaminants》2006,23(5):492-501
The distribution and elimination of fumonisins after oral administration of 50 mg FB1, 20 mg FB2 and 5 mg FB3 per animal day-1 for 22 days was studied in weaned barrows. At the end of the trial, the lung, heart, liver, kidney, spleen, brain, serum, bile, muscle, fat, urine and faeces samples were collected and their content of fumonisins (FB1, FB2) determined by LC-MS. The highest FB1 concentrations were found in the liver (99.4 ± 37.5 ng g-1) and kidneys (30.6 ± 10.1 ng g-1), whilst the highest average amount of FB2 was in the liver (1.4 ± 2.3 ng g-1) and fat (2.6 ng g-1 ± 4.8) samples. Comparing the FB1/FB2 ratio in different organs (19/1), it was found that the ratio in the abdominal and subcutaneous fat samples (4/1) was markedly different from those in all other tissues, namely the relative proportion of FB2 was higher in latter cases. Of the total quantity of FB1, the 13% taken up during 5 days was excreted unchanged with the faeces and urine. On average, in the urine and faeces, FB1 was detected in nine- and 14-fold quantities, as compared with FB2. 相似文献
52.
Johannes Staguhn Dominic Benford Eli Dwek Gene Hilton Dale Fixsen Kent Irwin Christine Jhabvala Attila Kovacs Samuel Leclercq Stephen Maher Tim Miller S. Harvey Moseley Elmer Sharp Edward Wollack 《Journal of Low Temperature Physics》2014,176(5-6):829-834
We present the main design features for the GISMO-2 bolometer camera, which we build for background-limited operation at the IRAM 30 m telescope on Pico Veleta, Spain. GISMO-2 will operate simultaneously in the 1 and 2 mm atmospherical windows. The 1 mm channel uses a \(32 \times 40\) TES-based backshort under grid (BUG) bolometer array, the 2 mm channel operates with a \(16 \times 16\) BUG array. The camera utilizes almost the entire full field of view provided by the telescope. The optical design of GISMO-2 was strongly influenced by our experience with the GISMO 2 mm bolometer camera, which is successfully operating at the 30 m telescope. GISMO is accessible to the astronomical community through the regular IRAM call for proposals. 相似文献
53.
Oxide layers were grown on tubular samples of Zr–1%Nb under conditions simulating those in VVER-type pressurised water reactors, viz. in near-neutral borate solutions in an autoclave at 290 °C. These samples were investigated using electrochemical impedance spectroscopy which was found to be suitable to follow in situ the corrosion process. A –CPEoxRox– element was used to characterise the oxide layer on Zr–1%Nb. Both the CPEox coefficient, σox, and the parallel resistance, Rox, were found to be thickness dependent. The layer thickness, however, can only be calculated after a calibration procedure. The temperature dependence of the CPEox element was also found to be anomalous while the temperature dependence of Rox indicates that the oxide layer has semiconductor properties. The relaxation time – defined as (Roxσox)1/ – was found to be quasi-independent of oxidation time and temperature; thus it is characteristic to the oxide layer on Zr–1%Nb. 相似文献
54.
55.
In response to M. L. Meltzer's (1975) article on insurance reimbursement for psychologists, the economic legitimacy that professional psychologist practitioners have secured over the past 2 decades is discussed. This legitimacy is illustrated by the US government's recognition that psychologists may now be reimbursed by insurance companies for providing psychotherapy for government employees. The effects that the enactment of national health insurance will have on the profession of psychology are addressed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
56.
57.
OBJECTIVE: Our aim was to determine the prevalence, histopathologic correlation, and clinical significance of multiple peripherally distributed echogenic foci seen within ovaries on transvaginal sonography. SUBJECTS AND METHODS: Transvaginal sonograms of 264 ovaries in 135 patients were prospectively analyzed for the presence of peripheral echogenic foci that were then characterized as linear, punctate, or globular. Previous examinations, when available, were reviewed for this sonographic feature, and the time interval between studies was recorded as a measure of stability. Sonograms were correlated with available surgical specimens in six patients, five of whom underwent hysterectomy and bilateral oophorectomy and the remaining patient who underwent laparoscopic ovarian wedge biopsy. RESULTS: Multiple peripheral echogenic foci were common and were found in 66 patients (49%) and 97 ovaries (37%). The punctate pattern was seen in 63 (95%) of 66 patients. The linear and globular patterns were present in only three and four patients, respectively. These echogenic foci were found on previous examinations in 18 patients. No suspicious sonographic features were seen in the ovaries of any of these patients. Histologic evaluation revealed multiple superficial epithelial inclusion cysts and associated psammomatous calcifications in all five patients who underwent bilateral oophorectomy. An additional finding in one of these patients was extensive endosalpingiosis. CONCLUSION: Multiple peripheral echogenic foci involving the ovaries is a common incidental finding on routine transvaginal sonography of the pelvis. Our data suggest that this sonographic finding represents psammomatous calcifications associated with superficial epithelial inclusion cysts. 相似文献
58.
59.
Relaxation techniques have been used increasingly in therapy with people who present with diverse anxiety and stress-related problems. Most applications, however, are aimed at a circumscribed problem area and use a specific relaxation procedure. The variety of patients and range of problems encountered in the evening mental health clinic of a teaching hospital prompted the authors to develop an approach that (1) incorporates a variety of cognitive and somatic techniques, (2) serves a heterogeneous population, (3) uses a time-limited group modality, and (4) encourages individual responsibility for selection and application of techniques. The content of each of the 6 sessions is described. Ss have indicated improvement in the areas of somatic complaints, interpersonal relationships, and sense of personal control. This approach appears to be a cost-effective way of teaching a heterogeneous population improved ways of coping with stress and encouraging individual responsibility for healthful behavior. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
60.
Wexley Kenneth N.; Yukl Gary A.; Kovacs Steven Z.; Sanders Raymond E. 《Canadian Metallurgical Quarterly》1972,56(1):45
Examined contrast effects by having 80 students watch 3 videotaped interviews of job applicants and rate them in terms of their job qualifications. 2 videotapes were used to establish a frame of reference; ratings of the 3rd were evaluated for contrast effects. It was found that contrast effects were statistically significant, but they accounted for a small part of the total variance in ratings when high- or low-suitability applicants were seen in the 3rd position. When an average applicant was preceded by 2 high- or 2 low-suitability applicants, however, contrast effects accounted for a substantial part (80%) of the total variance. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献