全文获取类型
收费全文 | 1394篇 |
免费 | 65篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 62篇 |
化学工业 | 359篇 |
金属工艺 | 34篇 |
机械仪表 | 14篇 |
建筑科学 | 31篇 |
矿业工程 | 1篇 |
能源动力 | 48篇 |
轻工业 | 160篇 |
水利工程 | 6篇 |
石油天然气 | 1篇 |
无线电 | 121篇 |
一般工业技术 | 275篇 |
冶金工业 | 223篇 |
原子能技术 | 45篇 |
自动化技术 | 83篇 |
出版年
2023年 | 17篇 |
2022年 | 24篇 |
2021年 | 31篇 |
2020年 | 23篇 |
2019年 | 22篇 |
2018年 | 27篇 |
2017年 | 31篇 |
2016年 | 42篇 |
2015年 | 29篇 |
2014年 | 52篇 |
2013年 | 72篇 |
2012年 | 67篇 |
2011年 | 87篇 |
2010年 | 50篇 |
2009年 | 71篇 |
2008年 | 64篇 |
2007年 | 52篇 |
2006年 | 53篇 |
2005年 | 44篇 |
2004年 | 47篇 |
2003年 | 40篇 |
2002年 | 34篇 |
2001年 | 24篇 |
2000年 | 27篇 |
1999年 | 32篇 |
1998年 | 82篇 |
1997年 | 55篇 |
1996年 | 38篇 |
1995年 | 30篇 |
1994年 | 26篇 |
1993年 | 27篇 |
1992年 | 21篇 |
1991年 | 10篇 |
1990年 | 8篇 |
1989年 | 9篇 |
1988年 | 3篇 |
1987年 | 9篇 |
1986年 | 9篇 |
1985年 | 8篇 |
1984年 | 7篇 |
1983年 | 7篇 |
1982年 | 10篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 8篇 |
1976年 | 7篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1972年 | 3篇 |
1968年 | 2篇 |
排序方式: 共有1463条查询结果,搜索用时 31 毫秒
31.
H Toyoshima S Hayashi N Tanabe K Miyanishi T Satoh Y Aizawa T Izumi 《Canadian Metallurgical Quarterly》1996,59(3-4):81-95
Epidemiological features, risk factors and preventive methods of sudden death (SD) derived from studies the authors have performed since 1987 together with colleagues in Niigata University School of Medicine were reviewed. When SD was defined as death occurring within 24 hours of the onset of symptoms, the annual incidence was 145/100,000 for people aged 15 years and older in Niigata Prefecture. The incidence increased sharply along with the advance of age, while the proportion of SD to natural death due to circulatory diseases was higher in younger people. Though diseases of the circulatory system made up approximately 90 percent of all causes of death, SD due to ischemic heart disease was less frequent in Japan than in western countries. SD showed various patterns in seasonal and "within-a-day" occurrences according to sex, age and cause of death. The months of the highest SD occurrence differed by occupation and matched the busiest work periods. A decrease in sleeping hours and mental stress experienced during the preceding week were related to the occurrence of both sudden death and non-fatal acute myocardial infarction. People having structural circulatory diseases were shown to be predisposed to SD when stress occurred, because fatal arrhythmia is easily induced by the above factors in such people. Health examinations were shown to have preventive effects, though limited, against SD. Differences in the resuscitated rates in cases where a witness was present and where one was not indicates that educating people about correct resuscitation methods is important to minimizing SD. 相似文献
32.
The activity of CaO in the CaO-ZrO2 system has been measured at 1572 to 1877 K with a Galvanic cell composed of 4CaO ? P2O5 as the solid electrolyte. The activity ZrO2 was calculated from the activity of CaO by integrating the Gibbs-Duhem relation. From the activities of CaO and ZrO2, the standard Gibbs free energy of formation of CaO ? ZrO2 was determined as follows: ΔG f 0 /J mol?1 = -25,200 (±150) - 17.58 (±0.085)T (1633 to 1873 K) 相似文献
33.
Tsuji S Kasumi T Nagase K Yoshikawa E Kobayashi H Kurita N 《Journal of molecular graphics & modelling》2011,29(8):975-984
During cancer invasion, the binding of urokinase-type plasminogen activator (uPA) to its receptor (uPAR) on the surface of a cancer cell is considered a trigger for invasion. Here, we present a stable structure of the solvated complex formed between uPA and uPAR (uPA-uPAR) and investigate the specific interactions between uPA and uPAR by ab initio fragment molecular orbital (FMO) calculations. The result indicates that the electrostatic interactions between the charged amino acid residues existing in both uPA and uPAR make a large contribution to the binding between uPA and uPAR. In particular, Lys23, Lys46, Lys98 and Lys61 of uPA are found to have strong attractive interactions with uPAR. To elucidate the effect of these residues on the interactions between uPA and uPAR, we substituted each of them with the uncharged amino acid Leu and investigated the interactions between the mutated uPA and wild-type uPAR. The interaction energies indicate that Lys46 and Lys98, which bind uPA to the rim of the central ligand-binding cavity of uPAR, make greater contributions to the binding between uPA and uPAR than Lys23, which is positioned at the bottom of the ligand-binding cavity of uPAR. The effect of hydrating water molecules located between uPA and uPAR is also investigated to be significant for the specific interactions between uPA and uPAR. These results are expected to be informative for developing new peptide antagonists that block the binding of uPA to uPAR. 相似文献
34.
Yoshifumi Morita Norihiro Toya Ryosuke Takeichi Hitomi Hattori Hirofumi Tanabe Yoshiaki Takagi 《Advanced Robotics》2016,30(21):1406-1414
We developed a new training system, called ‘UR-System 2’, for the recovery of motor function of a plegic upper limb after stroke. UR-System 2, which was redesigned based on knowledge gained from clinical tests using UR-System 1, was newly equipped with a function for testing the motor function of patients, such as isolated movement. In order to verify the effectiveness of UR-System 2, we conducted the following procedures: we verified the safety of training in healthy persons; we gathered standard data on pronation and supination of healthy forearms during tests; and, we verified that the test function was effective in evaluating the recovery effect of isolated movement in two hemiplegic patients. 相似文献
35.
36.
Keisuke Ichida Kiyotaka Izumi Keigo Watanabe Nobuhiro Uchida 《Artificial Life and Robotics》2008,12(1-2):258-263
In general, manipulators used for industry and in academic laboratories have actuators to drive each joint. On the other hand,
underactuated manipulators handled by our research have some passive or free joints without actuators and brakes. We recently
developed a switching method of fuzzy energy regions to control such manipulators. In such a method, it is necessary to design
parameters related to energy regions and the gains of some partly stable controllers based on the computed torque method.
Here, the switching method is applied for a three-link underactuated manipulator. We optimize such design parameters related
to fuzzy energy regions by a genetic algorithm. The effectiveness of the present method is illustrated with some simulations.
This work was presented in part at the 12th International Symposium on Artificial Life and Robotics, Oita, Japan, January
25–27, 2007 相似文献
37.
I Tanabe K Kusaba Z Nagasawa Y Tajima J Tadano N Fujisawa O Kato H Yamada 《Canadian Metallurgical Quarterly》1993,67(8):718-723
A recent nationwide increase in beta-lactams-resistant Streptococcus pneumoniae has attracted a great deal of attention. We studied the drug sensitivity of S. pneumoniae isolated from various clinical specimens in Saga Medical School Hospital between April 1988 and December 1991. To determine the drug sensitivity of the strains, we used a micro-dilution method and determined the MIC. Drug resistance was evaluated using MIC of ampicillin (ABPC) as a reference MIC, and the results were roughly classified into the following three groups: sensitive (< or = 0.1 microgram/ml), moderately resistant (0.2-3.13 micrograms/ml) and highly resistant (> or = 6.25 micrograms/ml). The isolation frequency was calculated on the basis of one strain from one patient. No strain of S. pneumoniae with high resistance against ABPC was found in 1988 (94 strains of S. pneumoniae were isolated) and 1990 (115 strains isolated), but one such strain (0.8%) was found among 129 strains isolated in 1989, and 2 such strains (2.4%) among 84 strains isolated in 1991. Moderately resistant strains were isolated at the frequencies of 12.8%, 15.5%, 22.6%, and 21.4% respectively, in 1988, 1989, 1990, and 1991. A sum of the frequencies of "moderately resistant" and "highly resistant" (2.4%) strains was 23.8% in 1991. The frequency of resistant strains is increasing and the intensity of resistance is also being elevated. 相似文献
38.
Etching characteristics of high-k dielectric materials (HfO2) and metal electrode materials (Pt, TaN) have been studied in high-density chlorine-containing plasmas at pressures around 10 mTorr. The etching of HfO2 was performed in BCl3 without rf biasing, giving an etch rate of about 5 nm/min with a high selectivity of >10 over Si and SiO2. The etching of Pt and TaN was performed in Ar/O2 with high rf biasing and in Ar/Cl2 with low rf biasing, respectively, giving a Pt etch rate of about several tens nm/min and a TaN etch rate of about 200 nm/min with a high selectivity of >8 over HfO2 and SiO2. The etched profiles were outwardly tapered for Pt, owing to the redeposition of etch or sputter products on feature sidewalls, while the TaN profiles were almost anisotropic, probably owing to the ion-enhanced etching that occurred. 相似文献
39.
We propose a quantum bit-commitment scheme based on quantum one-way permutations with the unconditionally binding and computationally
concealing property. Our scheme reduces exponentially the number of bits which the receiver needs to store until, the opening
phase compared with the classical counterpart.
Keisuke Tanaka, Ph.D.: He is Assistant Professor of Department of Mathematical and Computing Sciences at Tokyo Institute of Technology. He received
his B.S. from Yamanashi University in 1992 and his M.S. and Ph.D. from Japan Advanced Institute of Science and Technology
in 1994 and 1997, respectively. For each degree, he majored in computer science. Before joining Tokyo Institute of Technology,
he was Research Engineer at NTT Information Sharing Platform Laboratories. His research interests are cryptography, quantum
computation, circuit complexity, and the design and analysis of algorithms. 相似文献
40.