全文获取类型
收费全文 | 2972篇 |
免费 | 13篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 44篇 |
化学工业 | 256篇 |
金属工艺 | 111篇 |
机械仪表 | 127篇 |
建筑科学 | 44篇 |
矿业工程 | 8篇 |
能源动力 | 12篇 |
轻工业 | 74篇 |
水利工程 | 18篇 |
石油天然气 | 35篇 |
无线电 | 83篇 |
一般工业技术 | 303篇 |
冶金工业 | 1734篇 |
原子能技术 | 30篇 |
自动化技术 | 107篇 |
出版年
2022年 | 25篇 |
2021年 | 43篇 |
2020年 | 21篇 |
2019年 | 31篇 |
2018年 | 59篇 |
2017年 | 60篇 |
2016年 | 69篇 |
2015年 | 39篇 |
2014年 | 57篇 |
2013年 | 91篇 |
2012年 | 69篇 |
2011年 | 107篇 |
2010年 | 77篇 |
2009年 | 99篇 |
2008年 | 102篇 |
2007年 | 94篇 |
2006年 | 73篇 |
2005年 | 32篇 |
2004年 | 23篇 |
2003年 | 7篇 |
2002年 | 9篇 |
2001年 | 7篇 |
2000年 | 27篇 |
1999年 | 48篇 |
1998年 | 443篇 |
1997年 | 295篇 |
1996年 | 183篇 |
1995年 | 108篇 |
1994年 | 78篇 |
1993年 | 104篇 |
1992年 | 13篇 |
1991年 | 20篇 |
1990年 | 13篇 |
1989年 | 9篇 |
1988年 | 9篇 |
1987年 | 11篇 |
1986年 | 7篇 |
1985年 | 14篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 19篇 |
1981年 | 28篇 |
1980年 | 31篇 |
1979年 | 4篇 |
1978年 | 6篇 |
1977年 | 95篇 |
1976年 | 194篇 |
1975年 | 12篇 |
1973年 | 5篇 |
1966年 | 2篇 |
排序方式: 共有2986条查询结果,搜索用时 0 毫秒
31.
SV Murashkin SV Efremenko IuV Luzganov VA Belov 《Canadian Metallurgical Quarterly》1996,317(12):21-2, 80
The original decision of permanent introduction of antibacterial means to tissues of brain at gunshot meningoencephalitis is offered. For antibacterial therapy the intra-aortal catheter with diameter of 2,5 mm (through a.femoralis) was introduced. After washing the catheter by solution of crystalloid with heparin the various combinations of preparations in 5% solution of glucose were introduced: cephalosporin--8 g/day; hentamicin and brumacilin--240 mg/day accordingly, amicacin--1500 mg/day. Speed of introduction--20-50 mg/h, total volume--500 ml. The catheter was in aorta not more than 10 days, maximum--14 days. A described technique was applied in Burdenko Main Military Clinical Hospital on 34 wounded in head. At computer tomography of brain of all wounded intracranially the splinters and bullets were revealed, clinically--meningoencephalitis. Foreign bodies have been extracted after cupping of clinical and laboratory signs of meningoencephalitis. The authors consider, that the technique is effective not only at wounds of brain, but also at suppurative meningoencephalitis of other etiology. 相似文献
32.
VA Kniazhev 《Canadian Metallurgical Quarterly》1996,20(4):10-14
Reviews the state research and technological programs on priority trends in medical science. The programs are aimed at improving the nation's health. The emphasis in these programs is laid upon prophylactic medicine and the sociohygienic approach, underlying the health status of children and adults in the country. 相似文献
33.
34.
I. Yu. Grebennikov V. I. Gun’ko A. Ya. Dmitrishin L. I. Onishchenko S. O. Toporov T. A. Feshchuk 《Russian Electrical Engineering》2007,78(1):23-25
Methods for cleaning commercial T-1500 dielectric oil with different adsorbents are studied. The oil is intended for impregnation of high-voltage pulse capacitors with film dielectric. 相似文献
35.
Sixteen matching sera and DNA samples from healthy African blood donors living in rural areas of Guinea were analysed for the presence of type D retrovirus markers. Screening for the antibodies against structural proteins of Mason-Pfizer monkey virus (M-PMV) was carried out by Western blot with a purified M-PMV as an antigen. Eight out of 16 sera samples were found to contain antibodies against at least two gag gene-coded proteins, and three of these were weakly positive against env gene-coded protein. Using PCR amplification and Southern hybridization, we detected M-PMV-like gag sequences in 11 out of 16 samples and env-related sequences in 8 out of 16 samples. Six DNAs were found to contain both M-PMV gag- and env-related sequences. Restriction endonuclease analysis of the PCR-amplified gag sequences from two individuals and direct DNA sequencing analysis of the amplimers confirmed their M-PMV-like origin. Detection of antibodies and M-PMV-related sequences in blood donors from Guinea, but not in French or Algerian blood donors, indicated exogenous SRV infection in humans from certain geographic areas of Western Africa. 相似文献
36.
37.
38.
VA Barnes FA Treiber H Davis TR Kelley WB Strong 《Canadian Metallurgical Quarterly》1998,22(11):1079-1083
OBJECTIVE: To examine the impact of central adiposity upon hemodynamic functioning at rest and during stress in adolescents. DESIGN: Cross-sectional, correlational study. SUBJECTS: 46 White and 49 Black normotensive adolescents with family histories of essential hypertension. MEASUREMENTS: Systolic and diastolic blood pressure (SBP, DBP), cardiac output and total peripheral resistance responses were assessed at rest, during postural change, video game challenge and forehead cold stimulation. Specific lower and higher waist-to-hip ratio (WHR) tertiles were created for each gender and then integrated for analyses. This resulted in a lower WHR tertile of 11 Whites and 21 Blacks and an upper WHR tertile of 15 Whites and 17 Blacks. RESULTS: No differences in age, gender or ethnicity proportions were found between tertile groups (all P > 0.21). The upper WHR group showed greater body weight, waist and hip circumferences, body mass index (BMI), triceps skinfold and body surface area (all P < 0.001). Controlling for peripheral (that is, triceps skinfold) and overall (that is, BMI) adiposity, the upper WHR group exhibited greater SBP (that is, peak response minus mean pre-stressor level) to all three stressors and greater DBP reactivity to postural change and cold pressor (all P < 0.05). CONCLUSION: Central adiposity appears to adversely influence hemodynamic functioning during adolescence. Underlying mechanisms responsible for these associations require exploration. 相似文献
39.
O van der Heijden HC Chiu TC Park H Takahashi VA LiVolsi JI Risinger JC Barrett A Berchuck AC Evans K Behbakht AW Menzin PC Liu I Benjamin MA Morgan SA King SC Rubin J Boyd 《Canadian Metallurgical Quarterly》1998,23(4):243-247
The degree and nature of patient involvement in consultations with health professionals influences problem and needs recognition and management, and public accountability. This paper suggests a framework for understanding the scope for patient involvement in such consultations. Patients are defined as co-producers of formal health services, whose potential for involvement in consultations depends on their personal rights, responsibilities and preferences. Patients' rights in consultations are poorly defined and, in the National Health Service (NHS), not legally enforceable. The responsibilities of patients are also undefined. I suggest that these are not to deny, of their own volition, the rights of others, which in consultations necessitate mutuality of involvement through information-exchange and shared decision-making. Preferences should be met insofar as they do not militate against responsibilities and rights. 相似文献
40.
JG Izzo VA Papadimitrakopoulou XQ Li H Ibarguen JS Lee JY Ro A El-Naggar WK Hong WN Hittelman 《Canadian Metallurgical Quarterly》1998,17(18):2313-2322
Cyclin D1 proto-oncogene is a key regulator of the mammalian cell-cycle acting at the restriction point in late G1. Amplification of the cyclin D1 locus, located on chromosome 11q13, as well as cyclin D1 protein overexpression have been reported in several human malignancies. The purpose of this study was to evaluate cyclin D1 gene copy status and protein expression during the multistep process of head and neck tumorigenesis, using a combination of fluorescence in situ hybridization and immunohistochemistry techniques. From 29 selected patients presenting with head and neck squamous carcinoma and whose tumor cytospins had been previously screened for presence (16 cases) or absence (13 cases) of amplification at the 11q13 band, we analysed 46 paraffin-embedded tissue specimens that demonstrated, besides the primary tumor, the presence of contiguous adjacent normal tissue and/or premalignant lesions. Of the 16 amplified cases, nine demonstrated a continuous progression from premalignant to invasive carcinoma and seven (77.7%) of these cases showed cyclin D1 gene amplification in premalignant lesions prior to development of invasive carcinoma. Increased cyclin D1 protein expression was observed in all 16 amplified tumors and five of the 13 (38.4%) non-amplified tumors. Interestingly, dysregulated cyclin D1 expression was also found in the premalignant lesions adjacent to all 16 amplified tumors, and it appeared to precede cyclin D1 gene amplification. In contrast no dysregulated expression was detected in the premalignant lesions of the non-amplified tumors. In conclusion, these findings provide strong evidence for early dysregulation of cyclin D1 expression during the tumorigenesis process and suggest that dysregulated increased expression precedes and possibly enables gene amplification. 相似文献