全文获取类型
收费全文 | 2407篇 |
免费 | 52篇 |
国内免费 | 12篇 |
专业分类
电工技术 | 83篇 |
综合类 | 5篇 |
化学工业 | 533篇 |
金属工艺 | 115篇 |
机械仪表 | 73篇 |
建筑科学 | 35篇 |
矿业工程 | 1篇 |
能源动力 | 69篇 |
轻工业 | 160篇 |
水利工程 | 3篇 |
石油天然气 | 1篇 |
无线电 | 236篇 |
一般工业技术 | 335篇 |
冶金工业 | 643篇 |
原子能技术 | 49篇 |
自动化技术 | 130篇 |
出版年
2023年 | 8篇 |
2022年 | 25篇 |
2021年 | 38篇 |
2020年 | 17篇 |
2019年 | 14篇 |
2018年 | 31篇 |
2017年 | 15篇 |
2016年 | 29篇 |
2015年 | 28篇 |
2014年 | 38篇 |
2013年 | 90篇 |
2012年 | 59篇 |
2011年 | 99篇 |
2010年 | 73篇 |
2009年 | 88篇 |
2008年 | 111篇 |
2007年 | 96篇 |
2006年 | 64篇 |
2005年 | 76篇 |
2004年 | 62篇 |
2003年 | 68篇 |
2002年 | 65篇 |
2001年 | 65篇 |
2000年 | 53篇 |
1999年 | 61篇 |
1998年 | 218篇 |
1997年 | 165篇 |
1996年 | 119篇 |
1995年 | 72篇 |
1994年 | 64篇 |
1993年 | 66篇 |
1992年 | 34篇 |
1991年 | 25篇 |
1990年 | 28篇 |
1989年 | 19篇 |
1988年 | 22篇 |
1987年 | 21篇 |
1986年 | 12篇 |
1985年 | 19篇 |
1984年 | 16篇 |
1983年 | 11篇 |
1982年 | 24篇 |
1981年 | 18篇 |
1980年 | 24篇 |
1979年 | 24篇 |
1978年 | 8篇 |
1977年 | 19篇 |
1976年 | 37篇 |
1975年 | 11篇 |
1966年 | 4篇 |
排序方式: 共有2471条查询结果,搜索用时 15 毫秒
871.
In order to assess the role of hydrogen transport in hydrogen embrittlement, one of the kinetic aspects of hydrogen embrittlement,
the strain rate dependence, was analyzed in terms of hydrogen transport. The results have been analyzed in terms of a new
model which takes into account atomic and macroscopic diffusion in describing dislocation-hydrogen interactions. It was found
that the strong strain rate dependence of hydrogen embrittlement can be explained by a dynamic trapping effect, which is associated
with an increase in the population of dislocations during deformation. 相似文献
872.
K Shimizu T Hashimoto N Wang K Watanabe Y Ohata A Kikuchi M Amagai T Nishikawa 《Canadian Metallurgical Quarterly》1996,192(2):179-182
We report a case who was clinically and histopathologically diagnosed as herpetiform pemphigus (HP) and associated with autoimmune hemolytic anemia (AIHA). However, immunofluorescence studies demonstrated concurrent anti-cell-surface and anti-basement-membrane-zone antibodies in the patient's serum. Immunochemical studies showed that the patient's serum reacted with both the pemphigus foliaceus antigen and the two bullous pemphigoid antigens. Subsequently, the patient developed AIHA. Both anemia and skin lesions were successfully treated with oral prednisolone. We believe that this is the first case with HP in association with AIHA. The presence of autoantibodies against multiple antigens suggests an abnormal immunologic tolerance in the antibody production system in this patient. 相似文献
873.
Katsuki Kabemura Kazuhiko Yonekura Takanori Tsukamoto Keiichirou Hashimoto Masanori Hara 《Electrical Engineering in Japan》2004,146(1):27-36
This paper focuses on the application results of the dispersed autonomous voltage control system, which the authors have proposed, to a real distribution network. This system is effective for regulating the supply voltage of an entire HV line within an optimum range. In the system configuration, an SCC is installed together with an SC and/or ShR on the line. Individual SCCs autonomously control the operation of SCs and/or ShRs based on the voltage measured where the SCs and/or ShRs are located on the line. A field test on a real high‐voltage distribution network found that the proposed system could sustain a high fault tolerance ability and also be cost‐effective in regulating line voltage. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 146(1): 27–36, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10252 相似文献
874.
H Asano T Sone H Tsuboi H Sassa K Takeshima Y Miyazaki K Okumura H Hashimoto T Ito 《Canadian Metallurgical Quarterly》1993,71(11):902-908
The validity of dual energy single-photon emission computed tomography (SPECT) with technetium-99m pyrophosphate (Tc-99m PPi) and thallium-201 for the diagnosis of right ventricular (RV) infarction, and the clinical features of RV infarction, were investigated in 190 patients with acute myocardial infarction. Diagnosis of RV infarction was performed by Tc-99m PPi accumulation in the RV myocardium on thallium-201 and Tc-99m PPi over-lay images at the dual SPECT with simultaneous imaging taken 2 to 9 days after the onset of myocardial infarction. Thirty RV infarctions were found among the 190 patients with left ventricular infarction (15.8%): 29 (97%) in association with the inferior and 1 (3%) with the lateral infarction. Tc-99m PPi accumulation was mostly observed in the posterior wall of the right ventricle. A total occlusion or a severe stenosis of the right coronary artery was demonstrated angiographically in 92% of the patients with RV infarction. The prevalence of RV infarctions was significantly lower in patients who achieved successful early reperfusion than in those who did not (26.7 vs 68.4%, respectively, p < 0.01). However, a successful early reperfusion therapy could not significantly decrease the rate of RV involvement in patients without significant collateral flow (p < 0.01). Thus, dual isotope SPECT with Tc-99m PPi and thallium-201 can be used as a reliable method for the diagnosis of RV infarction. 相似文献
875.
876.
U Watanabe E Hashimoto T Hisamitsu H Obata N Hayashi 《Canadian Metallurgical Quarterly》1994,89(3):399-403
OBJECTIVES: To determine the risk factors for the development of thyroid diseases during interferon-alpha therapy, we analyzed the patients with chronic hepatitis C who were treated with interferon-alpha. METHODS: One hundred nine patients with chronic hepatitis C (77 men and 32 women, ages 20-72 yr) were treated with interferon-alpha (alpha, 48; alpha 2a, 38; alpha 2b, 23) for 14-40 wk. Thyroid function tests and seven autoantibodies were assessed at the beginning and end of interferon-alpha therapy, and every other month. A logistic multiple regression model was used in the statistical analysis of risk factors for development of thyroid diseases. RESULTS: Among the 106 patients with normal pretreatment thyroid function tests, nine patients (three men and six women, ages 33-62 yr) developed thyroid diseases. However, among three patients with abnormal thyroid function tests, exacerbation of thyroid disease was not observed during interferon-alpha therapy. Logistic multiple regression model revealed that positivity for microsome antibody was a significant risk factor for the development of thyroid disease (p < 0.0001, chi 2 = 20.18). Actually, compared to patients without microsome antibody at the beginning of therapy, the incidence of thyroid diseases in the patients with pretreatment microsome antibody was very high: 3.3% (3/99) versus 60% (6/10), respectively. Six patients developed hyperthyroidism and three patients developed hypothyroidism. The patients with hyperthyroidism had atypical clinical features. CONCLUSION: Our study revealed that positivity for microsome antibody at the beginning of interferon-alpha therapy is a risk factor for thyroid dysfunction. 相似文献
877.
K Arii T Suehiro M Yamamoto H Ito Y Ikeda Y Nakauchi K Hashimoto 《Canadian Metallurgical Quarterly》1997,36(9):603-606
We investigated the relationship between the Trp64Arg mutation in the beta 3-adrenergic receptor gene and insulin sensitivity, which was evaluated by the euglycemic-hyperinsulinemic-clamp technique, in 54 patients with impaired glucose tolerance (IGT) or non-insulin dependent diabetes mellitus (NIDDM) who were not receiving insulin therapy. The frequencies of Trp/Trp, Trp/Arg, and Arg/Arg genotypes in the patients were 63.0, 33.3, and 3.7%, respectively, which did not differ significantly from those of the 227 controls (67.0, 33.3, and 3.7%, respectively, which did not differ significantly from those of the 227 controls (67.0, 31.3, and 1.8%, respectively). The mean glucose infusion rate of the 34 patients with Trp/Trp did not differ from that of the 18 patients with Trp/Arg (4.3 +/- 2.2 and 5.3 +/- 2.4 mg/kg/min, respectively); while that of the 2 patients with Arg/Arg was 11.5 mg/kg/min. There were no differences in the BMI or fat distribution in the abdomen between each genotype of patients, although the frequency of the Arg64 allele tended to increase with body mass index (BMI) in the control subjects under 60 years of age, which suggests that the mutation is involved in weight gain. 相似文献
878.
Summary A new polyamide macromer having a vinylbenzyl end group (1), of which molecular weight was 3700–3800, was prepared by the anionic polymerization of bicyclic oxalactam (2) followed by the reaction with p-vinylbenzylamine. Its radical copolymerization with styrene was conducted to obtain a novel graft copolymer consisting of a polystyrene stock-chain and hydrophilic polyamide branches. 相似文献
879.
Widely (132 nm) wavelength tunable laser using a semiconductor optical amplifier and an acousto-optic tunable filter 总被引:1,自引:0,他引:1
Takabayashi K. Takada K. Hashimoto N. Doi M. Tomabechi S. Nakazawa T. Morito K. 《Electronics letters》2004,40(19):1187-1188
A widely wavelength tunable laser combining a semiconductor optical amplifier, an acousto-optic tunable filter and a Fabry-Perot etalon has been developed. It exhibited good characteristics over a 132 nm (1480-1612 nm) tuning range. 相似文献
880.