全文获取类型
收费全文 | 2388篇 |
免费 | 99篇 |
国内免费 | 11篇 |
专业分类
电工技术 | 132篇 |
综合类 | 3篇 |
化学工业 | 731篇 |
金属工艺 | 53篇 |
机械仪表 | 75篇 |
建筑科学 | 77篇 |
能源动力 | 107篇 |
轻工业 | 303篇 |
水利工程 | 11篇 |
石油天然气 | 1篇 |
无线电 | 108篇 |
一般工业技术 | 443篇 |
冶金工业 | 80篇 |
原子能技术 | 108篇 |
自动化技术 | 266篇 |
出版年
2023年 | 22篇 |
2022年 | 31篇 |
2021年 | 77篇 |
2020年 | 24篇 |
2019年 | 35篇 |
2018年 | 75篇 |
2017年 | 52篇 |
2016年 | 98篇 |
2015年 | 49篇 |
2014年 | 90篇 |
2013年 | 167篇 |
2012年 | 143篇 |
2011年 | 175篇 |
2010年 | 129篇 |
2009年 | 152篇 |
2008年 | 160篇 |
2007年 | 116篇 |
2006年 | 107篇 |
2005年 | 97篇 |
2004年 | 83篇 |
2003年 | 75篇 |
2002年 | 80篇 |
2001年 | 50篇 |
2000年 | 32篇 |
1999年 | 45篇 |
1998年 | 53篇 |
1997年 | 37篇 |
1996年 | 22篇 |
1995年 | 20篇 |
1994年 | 27篇 |
1993年 | 25篇 |
1992年 | 11篇 |
1991年 | 12篇 |
1990年 | 8篇 |
1989年 | 14篇 |
1988年 | 8篇 |
1987年 | 11篇 |
1986年 | 14篇 |
1985年 | 15篇 |
1984年 | 9篇 |
1983年 | 12篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 9篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1974年 | 4篇 |
排序方式: 共有2498条查询结果,搜索用时 15 毫秒
991.
Satoshi Akamaru Li Jin Katsuhiko Nishimura Masanori Hara Takayuki Abe Masao Matsuyama 《International Journal of Hydrogen Energy》2017,42(25):16305-16312
A new hydrogen sensor utilizing a ferromagnetic hydrogen absorbing alloy was developed. An optimum sensing element, Cu particles coated with Pd–Co hydrogen absorbing alloy was prepared by the barrel sputtering technique. The surface of prepared Cu particle was covered uniformly by Pd–Co thin layer constituted of aggregated nanoparticles. The sensitivity of the sensing element to H2 concentrations under flowing dry N2 and dry air gases was examined. The element has a reasonable sensitivity to the H2 concentration of the range from 3.8% to 0.2%, and the lower limit of detectable H2 concentration was estimated to be less than 0.1%. In dry air, the water formation on the Pd–Co surface affected its sensing ability, because the temperature of the sensing element increased by the exothermic reaction. The effect of moisture on the H2 sensing ability was also investigated. The moisture slightly degraded the output signal under flowing air. It could be ascribed to an additional consumption of hydrogen atoms by water molecules and oxygen atoms on the Pd–Co surface. This sensor takes advantage of magnetic susceptibility measurement, which requires no electrical wire between the sensing element and an electric circuit, leading to a safe evaluation system of H2 concentration in air. 相似文献
992.
Satoshi Ihara Masaki Kamatani Masashi Ishimine Saburo Sato Chobei Yamabe Hidenori Akiyama 《Electrical Engineering in Japan》2000,132(1):15-21
We have carried out experiments on TEA‐CO2 laser oscillation using the inductive energy storage pulsed‐power generator, which has a copper wire fuse as an opening switch. Maximum laser output energy of about 1 J/pulse was obtained in the case of a fuse length of 5 cm and energy storage inductance of 8 μH. The laser output energy depends on the energy storage inductance and the parameters of the fuse. In this paper, the dependencies of laser output energy on inductance and fuse length, and a comparison between the inductive and capacitive system were described. Furthermore the laser efficiency was discussed by calculating the electron energy distribution of laser main discharge region. © 2000 Scripta Technica, Electr Eng Jpn, 132(1): 15–21, 2000 相似文献
993.
Hiroo Nakamura Pietro Agostini Kuniaki Ara Satoshi Fukada Kazuyuki Furuya Pascal Garin Alessandro Gessi David Giusti Friedrich Groeschel Hiroshi Horiike Mizuho Ida Takuji Kanenmura Hiroo Kondo Nikolai Loginov Gioacchino Micciche Makoto Miyashita F.S. Nitti Akihiro Suzuki Takayuki Terai Kazuhiro Watanabe A. Mikheyev 《Fusion Engineering and Design》2009,84(2-6):252-258
In International Fusion Materials Irradiation Facility (IFMIF), intense neutron flux (4.5 × 1017 n/m2 s) with a peak energy of 14 MeV are produced by means of two deuteron beams with a total current of 250 mA and maximum energy of 40 MeV that strike a liquid Li target circulating in a Li loop. Major design requirement is to provide a stable Li jet at a speed of 10–20 m/s with a surface wave amplitude on the Li flow less than 1 mm for handling of an averaged heat flux of 1 GW/m2 under a continuous 10 MW deuterium beam deposition. The target system consists of a target assembly, a replaceable back-plate, a Li main loop and a Li purification loop. In July 2007, Engineering Validation and Engineering Design Activities (EVEDA) started under Broader Approach. In this paper, status of the engineering design of the IFMIF Li target system performed in 2007/2008 is described. The future EVEDA tasks to develop the target system are also summarized. 相似文献
994.
The SIMMER-IV computer code is a three-dimensional fluid-dynamics code coupled with a fuel-pin model and a space- and energy-dependent neutron transport kinetics model. The present study has attempted the first application of SIMMER-IV to a core disruptive accident in a large-scale sodium-cooled fast reactor. A principal point of this study was to investigate reactivity effects with fuel relocation under three-dimensional core representation including control rods. The calculation has indicated that the fuel discharge from the core was disturbed by a significant flow resistance at the entrance nozzle in the current design. Additional static neutronic calculations have been performed to compare basic neutronic characteristics between different scale cores. The static neutronic calculations have clarified that the outward fuel compaction within the inner core increased the reactivity in the large-scale core unlike the small-scale core. 相似文献
995.
Effect of Existence of Exogenous Protein on Physicochemical Properties of Heat- and Transglutaminase-induced Bovine Collagen-peptide Gel 总被引:1,自引:0,他引:1
Yuny Erwanto Satoshi Kawahara Kazunori Katayama Abdulatef M. Ahhmed Kiyoshi Yamauchi Koo B. Chin Michio Muguruma 《Journal of food science》2005,70(9):E505-E509
ABSTRACT: The combined influence of preheat treatment, mixing with various proteins, and the addition of microbial transglutaminase (MTGase) on the physicochemical properties of bovine collagen-peptide (BCP) gel was investigated. The preheat treatment and the mixing with various proteins contributed to the enhancement of the gel strength and polymerization of BCP. The gel made with 0.1% MTGase showed the highest breaking strength. The melting point of the preheated BCP gel was higher than that of the unheated one ( P < 0.05). The gel made with a combination of preheated BCP-casein or preheated BCP-soybean protein showed a higher melting point than that made with preheated BCP alone ( P < 0.05). The sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) pattern of the mixture of preheated BCP with casein or soybean protein showed that the protein bands with relatively low molecular weights disappeared and the bands with relatively high molecular weights increased. Observation by a scanning electron microscope revealed that the preheated BCP gel prepared with MTGase had a well-defined cross-linked network and showed some clumps of aggregated proteins. These results show that preheating, mixing with other proteins and MTGase treatment, are effective ways to make BCP a fine biopolymer. 相似文献
996.
Yokoyama M Miwa H Maeda S Wakitani S Takagi M 《Journal of Bioscience and Bioengineering》2008,106(1):46-50
Mesenchymal stem cells (MSCs) should be expanded in vitro while maintaining their multilineage potential before differentiation to one mesenchymal lineage for application to regeneration therapy. The effect of fetal calf serum (FCS) on undesirable differentiation during subcultivations for the expansion was investigated. The expression level of the aggrecan gene, which is a marker of chondrogenic differentiation, gradually and markedly increased during the subcultivations of MSCs with the addition of 10% FCS and without additional cytokines. The percentage of cells positive for CD90 and CD166, which are markers of MSCs, decreased, and the percentage of large polygonal cells and the average cell adhesion area increased during the expansion. There was a marked difference in the increase in the aggrecan expression level between the two expansion cultures employing different FCS lots, although their proliferation rates were almost the same. The decrease in FCS concentration resulted in a higher percentage of CD90(+)CD166(+) cells, a lower percentage of large polygonal cells, and a lower level of aggrecan expression. Consequently, FCS components could stimulate MSC differentiation to chondrocytes and a lower concentration could decrease this differentiation. 相似文献
997.
Hashimoto S Suzuki T Shirota Y Honma M Itabashi Y Chyounan T Kamiyama T 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2006,47(2):33-40
Lipophilic toxins associated with diarrhetic shellfish poisoning (DSP) in scallops, Patinopecten yessoensis, collected in Hokkaido, Japan were quantified by liquid chromatography-mass spectrometry (LC/MS). Pectenotoxin-6 (PTX6) and yessotoxin (YTX) were the dominant toxins in the scallops, although the percentages of these toxins were different depending on the production area or the sampling period. The quantitative results obtained for the scallops in LC/MS and in mouse bioassay (MBA) were compared. Fifty of the 55 samples found to be exceeding the local quarantine level (0.025 MU/g whole meat) in Hokkaido by LC/MS were quantified by MBA as being below the quarantine level. It is suggested that this discrepancy is due to poor detection of YTX by MBA. These results indicate that LC/MS is a better method than MBA in terms of sensitivity and accuracy to quantify known lipophilic toxins, including YTX. 相似文献
998.
Terada A Hibiya K Nagai J Tsuneda S Hirata A 《Journal of Bioscience and Bioengineering》2003,95(2):170-178
A membrane-aerated biofilm reactor (MABR) capable of simultaneous nitrification and denitrification in a single reactor vessel was developed to investigate the characteristics of nitrogen removal from high-strength nitrogenous wastewater, and biofilm analysis using microelectrodes and the fluorescence in situ hybridization (FISH) technique was performed. Mean removal percentages of total organic carbon (TOC) and nitrogen were 96% and 83% at removal rates of 5.76 g-C m(-2) d(-1) and 4.48 g-N m(-2) d(-1), respectively. For stable removal efficiency, constant washing of the biofilm was needed. Dissolved oxygen microelectrode measurement revealed that the biofilm thickness was about 1600 microm, and that oxygen penetrated about 300 to 700 microm, from the outer surface of the membrane. Furthermore, FISH analysis revealed that ammonia-oxidizing bacteria (AOB) were located near the outer surface of the membrane, whereas other bacteria were located from the inner to the outer part of the biofilm. Combining these results demonstrated that simultaneous nitrification and denitrification occurred in the biofilm of the MABR system. In addition, stoichiometric analysis revealed that after 130 d(-1), the free ammonia (FA) concentration ranged within the concentration causing inhibition of the growth of nitrite oxidizing bacteria (NOB) and that AOB consumed 86% of the oxygen supplied through the intra-membrane. These results indicate that nitrogen removal not via nitrate but via nitrite was mainly achieved in the MABR system. 相似文献
999.
Daisuke Ikeda SungGi Chi Satoshi Uchiyama Hirotaka Nakamura Yong-Mei Guo Nobuhiko Yamauchi Junichiro Yuda Yosuke Minami 《International journal of molecular sciences》2022,23(11)
The European LeukemiaNet (ELN) criteria define the adverse genetic factors of acute myeloid leukemia (AML). AML with adverse genetic factors uniformly shows resistance to standard chemotherapy and is associated with poor prognosis. Here, we focus on the biological background and real-world etiology of these adverse genetic factors and then describe a strategy to overcome the clinical disadvantages in terms of targeting pivotal molecular mechanisms. Different adverse genetic factors often rely on common pathways. KMT2A rearrangement, DEK-NUP214 fusion, and NPM1 mutation are associated with the upregulation of HOX genes. The dominant tyrosine kinase activity of the mutant FLT3 or BCR-ABL1 fusion proteins is transduced by the AKT-mTOR, MAPK-ERK, and STAT5 pathways. Concurrent mutations of ASXL1 and RUNX1 are associated with activated AKT. Both TP53 mutation and mis-expressed MECOM are related to impaired apoptosis. Clinical data suggest that adverse genetic factors can be found in at least one in eight AML patients and appear to accumulate in relapsed/refractory cases. TP53 mutation is associated with particularly poor prognosis. Molecular-targeted therapies focusing on specific genomic abnormalities, such as FLT3, KMT2A, and TP53, have been developed and have demonstrated promising results. 相似文献
1000.
Kazufumi Nakamura Toru Miyoshi Masashi Yoshida Satoshi Akagi Yukihiro Saito Kentaro Ejiri Naoaki Matsuo Keishi Ichikawa Keiichiro Iwasaki Takanori Naito Yusuke Namba Masatoki Yoshida Hiroki Sugiyama Hiroshi Ito 《International journal of molecular sciences》2022,23(7)
There is a close relationship between diabetes mellitus and heart failure, and diabetes is an independent risk factor for heart failure. Diabetes and heart failure are linked by not only the complication of ischemic heart disease, but also by metabolic disorders such as glucose toxicity and lipotoxicity based on insulin resistance. Cardiac dysfunction in the absence of coronary artery disease, hypertension, and valvular disease is called diabetic cardiomyopathy. Diabetes-induced hyperglycemia and hyperinsulinemia lead to capillary damage, myocardial fibrosis, and myocardial hypertrophy with mitochondrial dysfunction. Lipotoxicity with extensive fat deposits or lipid droplets is observed on cardiomyocytes. Furthermore, increased oxidative stress and inflammation cause cardiac fibrosis and hypertrophy. Treatment with a sodium glucose cotransporter 2 (SGLT2) inhibitor is currently one of the most effective treatments for heart failure associated with diabetes. However, an effective treatment for lipotoxicity of the myocardium has not yet been established, and the establishment of an effective treatment is needed in the future. This review provides an overview of heart failure in diabetic patients for the clinical practice of clinicians. 相似文献