全文获取类型
收费全文 | 4564篇 |
免费 | 6篇 |
专业分类
电工技术 | 8篇 |
化学工业 | 64篇 |
金属工艺 | 7篇 |
机械仪表 | 10篇 |
建筑科学 | 39篇 |
矿业工程 | 2篇 |
能源动力 | 7篇 |
轻工业 | 28篇 |
水利工程 | 2篇 |
无线电 | 22篇 |
一般工业技术 | 51篇 |
冶金工业 | 4302篇 |
原子能技术 | 6篇 |
自动化技术 | 22篇 |
出版年
2021年 | 3篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2014年 | 4篇 |
2013年 | 8篇 |
2012年 | 11篇 |
2011年 | 16篇 |
2010年 | 7篇 |
2009年 | 14篇 |
2008年 | 7篇 |
2007年 | 5篇 |
2006年 | 19篇 |
2005年 | 17篇 |
2004年 | 7篇 |
2003年 | 21篇 |
2002年 | 15篇 |
2001年 | 8篇 |
2000年 | 9篇 |
1999年 | 145篇 |
1998年 | 1430篇 |
1997年 | 801篇 |
1996年 | 527篇 |
1995年 | 265篇 |
1994年 | 239篇 |
1993年 | 261篇 |
1992年 | 34篇 |
1991年 | 46篇 |
1990年 | 39篇 |
1989年 | 49篇 |
1988年 | 48篇 |
1987年 | 26篇 |
1986年 | 29篇 |
1985年 | 26篇 |
1984年 | 10篇 |
1983年 | 13篇 |
1982年 | 16篇 |
1981年 | 20篇 |
1980年 | 41篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1977年 | 86篇 |
1976年 | 196篇 |
1975年 | 7篇 |
1973年 | 2篇 |
1967年 | 4篇 |
1966年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有4570条查询结果,搜索用时 15 毫秒
51.
More inpatient hospital days are used for the care of diabetic foot infection than for any other diabetic sequela. Both the number of lower extremity amputations and the overall treatment cost of treating diabetic infections may be reduced by using a team approach in the care of the infected diabetic pedal wound. The authors propose an evaluation and treatment protocol of infected pedal ulcerations in an urban, community teaching institution when admitted to an established, multidisciplinary diabetic foot care team. The hospital course of 111 patients admitted with a primary diagnosis of infected pedal ulceration are retrospectively reviewed. Results revealed an average-length hospital stay of 7.4 days with a 96% limb-salvage rate. The authors suggest that in the treatment of the infected pedal wound, a diabetic foot care team with a well developed treatment protocol may yield a consistently favorable outcome and a cost-effective hospital course. 相似文献
52.
53.
Phenotypic analysis of antigen-specific T lymphocytes 总被引:4,自引:0,他引:4
JD Altman PA Moss PJ Goulder DH Barouch MG McHeyzer-Williams JI Bell AJ McMichael MM Davis 《Canadian Metallurgical Quarterly》1996,274(5284):94-96
Identification and characterization of antigen-specific T lymphocytes during the course of an immune response is tedious and indirect. To address this problem, the peptide-major histocompatability complex (MHC) ligand for a given population of T cells was multimerized to make soluble peptide-MHC tetramers. Tetramers of human lymphocyte antigen A2 that were complexed with two different human immunodeficiency virus (HIV)-derived peptides or with a peptide derived from influenza A matrix protein bound to peptide-specific cytotoxic T cells in vitro and to T cells from the blood of HIV-infected individuals. In general, tetramer binding correlated well with cytotoxicity assays. This approach should be useful in the analysis of T cells specific for infectious agents, tumors, and autoantigens. 相似文献
54.
55.
Metabolism and biochemical effects of 3,3',4,4'-tetrachlorobiphenyl in pregnant and fetal rats 总被引:1,自引:0,他引:1
DC Morse EK Wehler M van de Pas AT de Bie PJ van Bladeren A Brouwer 《Canadian Metallurgical Quarterly》1995,95(1-2):41-56
The metabolism and distribution of a single oral dose of 25 mumol 14C-labelled 3,3',4,4'-tetrachlorobiphenyl (14C-TCB) were investigated in pregnant female Wistar rats and their fetuses. TCB was administered on day 13 of gestation and the elimination was followed for 7 days. Non-pregnant rats were treated similarly for comparison. Fecal elimination of 14C-TCB derived radioactivity was significantly lower in pregnant rats than in non-pregnant rats. The major metabolite found in adult liver and plasma, placental tissue, whole fetuses and fetal plasma was 3,3',4',5-tetrachloro-4-biphenylol (4-OH-TCB). Tissue levels (liver, abdominal fat, skin, skeletal muscle, kidney and plasma) of 14C-TCB-derived radioactivity declined by 65-85% over a 7-day period following administration in the adult animals. However, 14C-TCB-derived radioactivity accumulated more than 100-fold in the fetuses over the same time period, and GC/MS analysis revealed that the fetal accumulation in radioactivity was due primarily to 4-OH-TCB, and not the parent compound. On day 20 of gestation, concentrations of 4-OH-TCB were 14 times greater in fetal plasma than maternal plasma. Treatment with 14C-TCB significantly reduced plasma thyroxine levels by at least 28% up to 7 days after administration in non-pregnant animals and up to 4 days after administration in pregnant rats (31% decrease). By 7 days after administration plasma thyroxine levels had returned to control levels in the TCB-treated pregnant rats. However, fetal plasma thyroxine levels were significantly decreased by 35% in fetuses from 14C-TCB-treated dams 7 days after TCB administration. Hepatic microsomal ethoxyresorufin-O-deethylase (EROD) activity was significantly induced in TCB-treated dams relative to controls at 4 and 7 days after administration, while no EROD activity was detected in hepatic microsomes from control or TCB treated fetal rats at day 20 of gestation. These data suggest that hydroxylated metabolites of polychlorinated biphenyls may play a role in the development toxicity of these compounds. 相似文献
56.
57.
Over a 2-year period eight patients underwent percutaneous fluoroscopic fixation of their acetabular fractures. Average patient age was 43 and mean ISS was 27. Mean blood loss was less than 100 ml. There were five transverse fractures, one affecting both columns, one anterior column-posterior hemitransverse and one T-type fracture. There were two ipsilateral femoral and two ipsilateral tibial fractures. Mean follow-up was 15 months. Three broad patient groups were identified. One patient died, one was lost to follow-up, four had full range of motion of the affected hip, one had good range with Brooker II heterotopic ossification and one was wheelchair-bound with Brooker IV heterotopic ossification. The technique, which requires only cannulated screws and fluoroscopy, is described. 相似文献
58.
59.
Clostridium tertium bacteremia is unusual, seen most often with gastrointestinal disease and/or neutropenia. Two cases are described. The first was a 19-yr-old female with acute leukemia, who developed gastrointestinal symptoms and C. tertium bacteremia while neutropenic. The second was a 57-yr-old female with quiescent ulcerative colitis, who presented with fever, rigors and epigastric pain. Four organisms including C. tertium were isolated from blood cultures. This patient responded to broad spectrum antimicrobial therapy, whereas the first patient required the addition of specific agents to recover. C. tertium is aerotolerant and thus can be misidentified as a Bacillus or Corynebacterium spp. Our isolates had a distinctive Gram stain morphology, were catalase negative and failed to sporulate aerobically--this aided in the recognition of this significant Gram-positive bacillus. 相似文献
60.
RE Droleskey PJ Holman KA Waldrup DE Corrier GG Wagner 《Canadian Metallurgical Quarterly》1993,79(3):424-434
Babesia odocoilei continuously cultured in white-tailed deer (Odocoileus virginianus) erythrocytes was examined by transmission and scanning electron microscopy. Merozoites, trophozoites, intermediate-stage forms, and dividing forms were observed. Merozoites possessed a single nucleus, inner membrane complex, rhoptries, free ribosomes, rough endoplasmic reticulum, and single membrane-bound vesicles. Trophozoites lacked an inner membrane complex and rhoptries. Intermediate stages were characterized by distinct segments of inner membrane complex. Dividing forms ranged from cells with an elongated nucleus to mature daughter cells joined by a ringlike structure. Babesia odocoilei was characterized by its close proximity to the erythrocyte membrane, membranous structures resembling feeding organelles, and reproduction via a method resembling budding sensu stricto. 相似文献