全文获取类型
收费全文 | 942篇 |
免费 | 17篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 46篇 |
化学工业 | 214篇 |
金属工艺 | 15篇 |
机械仪表 | 15篇 |
建筑科学 | 12篇 |
能源动力 | 43篇 |
轻工业 | 85篇 |
水利工程 | 1篇 |
无线电 | 77篇 |
一般工业技术 | 179篇 |
冶金工业 | 176篇 |
原子能技术 | 25篇 |
自动化技术 | 74篇 |
出版年
2022年 | 6篇 |
2021年 | 16篇 |
2020年 | 5篇 |
2019年 | 9篇 |
2018年 | 10篇 |
2017年 | 11篇 |
2016年 | 14篇 |
2015年 | 14篇 |
2014年 | 33篇 |
2013年 | 41篇 |
2012年 | 43篇 |
2011年 | 50篇 |
2010年 | 32篇 |
2009年 | 37篇 |
2008年 | 51篇 |
2007年 | 35篇 |
2006年 | 23篇 |
2005年 | 30篇 |
2004年 | 20篇 |
2003年 | 38篇 |
2002年 | 20篇 |
2001年 | 18篇 |
2000年 | 22篇 |
1999年 | 17篇 |
1998年 | 71篇 |
1997年 | 48篇 |
1996年 | 42篇 |
1995年 | 19篇 |
1994年 | 16篇 |
1993年 | 18篇 |
1992年 | 10篇 |
1991年 | 13篇 |
1990年 | 8篇 |
1989年 | 6篇 |
1988年 | 9篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 6篇 |
1984年 | 9篇 |
1983年 | 13篇 |
1982年 | 10篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1978年 | 5篇 |
1977年 | 6篇 |
1976年 | 13篇 |
1975年 | 5篇 |
1974年 | 5篇 |
1971年 | 3篇 |
1970年 | 2篇 |
排序方式: 共有962条查询结果,搜索用时 0 毫秒
31.
Two azurin-type blue copper proteins, which is concerned with the electron transport chain involved in methylamine/methanol oxidation, have been found in the obligate methylotroph Methylomonas sp. strain J. The azurin iso-1 gene was cloned and sequenced to analyze the role in the electron transport chain. PCR products synthesized with primers based on the N- and C-terminal amino acid sequences of azurin iso-1 were used as probes for cloning. One complete open reading frame (the azurin iso-1 gene) and one partial orf (orf1) were found in a cloned Eco105I-HindIII fragment, pMAZ3, with a total of 1066 bp. The gene encoded 148 amino acid residues. The amino acid sequence after Ala-21, deduced from the nucleotide sequence, was identical to that of the azurin iso-1 protein. The gene was in a region separate from the mau gene cluster in the chromosome. Escherichia coli expressed azurin iso-1. The results of northern blotting analysis suggested that expression of the azurin iso-1 gene is regulated by a complex regulatory network controlling oxidation of methylamine or methanol in this strain; for example, copper ions affected the expression of the azurin iso-1 gene. 相似文献
32.
T Shiina G Tamiya A Oka T Yamagata N Yamagata E Kikkawa K Goto N Mizuki K Watanabe Y Fukuzumi S Taguchi C Sugawara A Ono L Chen M Yamazaki H Tashiro A Ando T Ikemura M Kimura H Inoko 《Canadian Metallurgical Quarterly》1998,47(3):372-382
The biomechanics of medialization laryngoplasty are not well understood. An excised canine larynx model was used to test the effects of various sized silicon implants. The vocal fold length, position, and tension were measured. Medialization laryngoplasty did not affect vocal fold length. At the mid-membranous vocal fold, larger shims resulted in greater medialization and tension. Medialization laryngoplasty neither medialized nor stiffened the vocal process to resist lateralizing forces. We conclude that medialization laryngoplasty provides bulk and support for defects of the membranous region of the vocal fold, but does not appear to close a posterior glottal gap. The selection of a surgical procedure to treat glottal incompetence should take into account the unique biomechanical properties of the anterior (membranous vocal folds) and posterior (cartilaginous portion) glottis. 相似文献
33.
We investigated the effects of YM294, recombinant human interleukin-11, on changes in blood cell levels in carboplatin-treated rats. Continuous infusion of YM294 was carried out by either intravenous or subcutaneous injection (10 and 100 micrograms/rat/day) for 14 days via an implanted osmotic pump. Carboplatin (30 mg/kg iv) significantly decreased platelet counts on days 7-9; counts subsequently increased to levels greater than the initial level by day 21. Intravenous administration of YM294 inhibited this decrease in platelet count by carboplatin and increased the platelet count in the recovery phase in a dose-dependent manner. YM294 also showed effects on carboplatin-induced changes in white blood cell and red blood cell counts; these effects seemed, however, to be neither consistent nor dose-dependent. The effects of YM294 on subcutaneous infusion were similar to those on intravenous infusion. The effect of YM294 on the survival of rats treated with a higher dose of carboplatin (60 mg/kg iv) was also investigated. YM294 (100 micrograms/rat/day) given by continuous intravenous infusion increased the 30-day survival rate. These results confirm the utility of YM294 in the treatment of thrombocytopenia after chemotherapy. 相似文献
34.
The purpose of this study is to develop an approach for unified constitutive modeling based on experimentally determined back stress and overstress. Back stress and overstress were experimentally determined for Type 316 stainless steel at 600°C, by analyzing the unloading curve for the stress-strain response of cyclic strain tests. The result has indicated that the cyclic strain hardening behavior is mainly caused by hardening in the back stress. A phenomenological unified constitutive model in which the back stress and drag stress are taken as the internal state variables is proposed, and has been shown that this model is able to simulate the cyclic inelastic behavior. 相似文献
35.
N Keicho K Tokunaga K Nakata Y Taguchi A Azuma M Bannai M Emi N Ohishi Y Yazaki S Kudoh 《Canadian Metallurgical Quarterly》1998,158(3):846-850
Diffuse panbronchiolitis (DPB) in East Asia is a distinctive chronic obstructive pulmonary disease of unknown etiology. We hypothesize that the disease susceptibility is due to genetic predisposition unique to Asians. Association between human leukocyte antigen (HLA)-Bw54 and the disease was previously reported. In the present study, using newly developed polymerase chain reaction (PCR)- based methods, we directly analyzed HLA class I and II alleles in 76 Japanese patients. HLA-A, -B, and -C antigens were screened by the conventional typing method, and then B22-group alleles including HLA-B54 were genotyped by single-strand conformation polymorphism analysis. Alleles of HLA-DRB1 gene were fully determined by the microtiter plate hybridization method. Thirty-seven percent of the patients possessed HLA-B*5401 allele conserved predominantly in East Asians, as compared with 15% of 110 healthy volunteers (chi2 = 12.4, p = 0.0004). In addition, 4% of the patients possessed B*5504 also unique to Asians but a rare allele which was not found in normal control subjects in this study. Typing of HLA-DRB1 class II gene did not demonstrate strong positive association with the disease. A33, B44, and DRB1*1302 showed negative association with the disease. We conclude that distinctive molecular structure of HLA-B alleles or a closely linked gene in the HLA region contributes to genetic predisposition in diffuse panbronchiolitis. This may partly explain why this disorder is found primarily in Asians. 相似文献
36.
R Hirose S Suita T Taguchi T Koyanagi H Nakano 《Canadian Metallurgical Quarterly》1995,30(9):1390-1393
An infant girl with extralobar pulmonary sequestration (PS) composed of congenital cystic adenomatoid malformation (CCAM)-like structure is presented. Initially, the antenatal sonographic findings indicated CCAM. The macroscopic findings of the resected specimen were compatible with extralobar PS; however, the microscopic findings showed cystic structure mimicking type II CCAM. The combination of PS and CCAM is rare, and it is likely that the embryological origin is common to both. There is confusion in the classification of these two congenital anomalies. In this report, the histological and sonographic findings of PS and CCAM are discussed. 相似文献
37.
T Taguchi S Tsukagoshi H Furue H Niitani K Noda 《Canadian Metallurgical Quarterly》1998,25(12):1899-1907
Oxaliplatin is a new platinum derivative. A multicentric phase I study was conducted with a monotherapy of Oxaliplatin. A total of 20 patients were enrolled who had histologically proven 6 ovarian cancers, 5 uterine cervix cancers, 3 lung cancers, 3 breast cancers, 1 endometrial cancer, 1 gastric cancer, and 1 colorectal cancer. Oxaliplatin was administered as a 2-hour infusion at doses of 20, 40, 80, 130, and 180 mg/m2 every 3 weeks, for a total of 30 cycles. A dose-related and reversible peripheral sensory neuropathy was the dose-limiting toxicity with minimal hematotoxicity and no nephrotoxicity. No hydration was needed. The plasma platinum concentration was biphasically decreased. Cmax and AUC were dose-dependent. T1/2 beta was 31.3 hours. The recommended dose for further studies was 130 mg/m2. A partial response was observed in endometrial cancer. 相似文献
38.
39.
In the past decade it has been suggested that the isotopic enrichment of 28-silicon enhances its thermal properties. Thus, 28-silicon is suitable as a heat sink in large-scale integrated circuits. Although some studies have focused on the measurement of isotopically enriched silicon's thermal properties, accurate experimental data are not sufficient because of this material's high conductivity and large heat capacity which make measurement difficult. However, the dynamic grating radiometry (DGR) method has been successfully developed to measure the thermal diffusivity of 28-silicon. In the DGR method, the sample is heated by interference of two pulsed laser beams, and the temperature decay is monitored by an infrared detector. By analyzing the temperature changes of the peaks and valleys of the thermal grating, the thermal diffusivities parallel and perpendicular to the sample surface are obtained simultaneously. In this paper, the optimum conditions of the experimental setup for measuring isotopically enriched silicon are discussed. The comparison of thermal diffusivities between 28-silicon and natural silicon (with a thickness of about 100m) is presented, and the applicability of DGR to isotope engineering is reported. 相似文献
40.
Fluorescent molecular thermometers based on polymers showing a temperature-induced phase transition and labeled with polarity-sensitive fluorescent benzofurazans are the most sensitive known. Here we show a simple and effective method for modulating the sensitive temperature ranges of fluorescent molecular thermometers based on such temperature-responsive polymers. 4-N-(2-acryloyloxyethyl)-N-methylamino-7-N,N-dimethylaminosulfonyl-2,1,3-benzoxadiazole was adopted as a polarity-sensitive fluorescent benzofurazan, and nine copolymers of two kinds of acrylamide derivative (N-n-propylacrylamide, N-isopropylacrylamide, and/or N-isopropylmethacrylamide) with a small amount of DBD-AE were obtained. The fluorescence intensities of these copolymers in aqueous solution sharply increased with increasing temperature over a small range (6-7 degrees C). In contrast, these fluorescent molecular thermometers differed from one another in the sensitive temperature range (between 20 and 49 degrees C). Moreover, the sensitive temperature ranges were well related to the acrylamide ratios in feed. In addition, the responses from these fluorescent molecular thermometers to the change in temperature were reversible and exactly repeatable during 10 cycles of heating and cooling (relative standard deviation of the fluorescence intensity, 0.44-1.0%). 相似文献