全文获取类型
收费全文 | 925篇 |
免费 | 16篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 79篇 |
化学工业 | 244篇 |
金属工艺 | 23篇 |
机械仪表 | 14篇 |
建筑科学 | 6篇 |
能源动力 | 59篇 |
轻工业 | 83篇 |
水利工程 | 4篇 |
无线电 | 67篇 |
一般工业技术 | 176篇 |
冶金工业 | 77篇 |
原子能技术 | 26篇 |
自动化技术 | 84篇 |
出版年
2023年 | 4篇 |
2022年 | 16篇 |
2021年 | 23篇 |
2020年 | 15篇 |
2019年 | 6篇 |
2018年 | 11篇 |
2017年 | 10篇 |
2016年 | 25篇 |
2015年 | 13篇 |
2014年 | 30篇 |
2013年 | 43篇 |
2012年 | 44篇 |
2011年 | 63篇 |
2010年 | 34篇 |
2009年 | 53篇 |
2008年 | 52篇 |
2007年 | 52篇 |
2006年 | 44篇 |
2005年 | 28篇 |
2004年 | 27篇 |
2003年 | 34篇 |
2002年 | 22篇 |
2001年 | 16篇 |
2000年 | 21篇 |
1999年 | 21篇 |
1998年 | 37篇 |
1997年 | 40篇 |
1996年 | 19篇 |
1995年 | 13篇 |
1994年 | 14篇 |
1993年 | 12篇 |
1992年 | 7篇 |
1991年 | 8篇 |
1990年 | 8篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 12篇 |
1978年 | 1篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有942条查询结果,搜索用时 15 毫秒
81.
Takeshi Kikuchi Makio Mogi Iichiro Okabe Kosuke Okada Hisashi Goto Yasuyuki Sasaki Takeki Fujimura Mitsuo Fukuda Akio Mitani 《International journal of molecular sciences》2015,16(10):24111-24126
Periodontal disease is caused by dental plaque biofilms, and the removal of these biofilms from the root surface of teeth plays a central part in its treatment. The conventional treatment for periodontal disease fails to remove periodontal infection in a subset of cases, such as those with complicated root morphology. Adjunctive antimicrobial photodynamic therapy (aPDT) has been proposed as an additional treatment for this infectious disease. Many periodontal pathogenic bacteria are susceptible to low-power lasers in the presence of dyes, such as methylene blue, toluidine blue O, malachite green, and indocyanine green. aPDT uses these light-activated photosensitizer that is incorporated selectively by bacteria and absorbs a low-power laser/light with an appropriate wavelength to induce singlet oxygen and free radicals, which are toxic to bacteria. While this technique has been evaluated by many clinical studies, some systematic reviews and meta-analyses have reported controversial results about the benefits of aPDT for periodontal treatment. In the light of these previous reports, the aim of this review is to provide comprehensive information about aPDT and help extend knowledge of advanced laser therapy. 相似文献
82.
Yoshinari Sawama Masahiro Masuda Ryosuke Nakatani Hiroki Yokoyama Yasunari Monguchi Toshifumi Dohi Yasuyuki Kita Hironao Sajiki 《Advanced Synthesis \u0026amp; Catalysis》2016,358(23):3683-3687
The iron(III) chloride‐catalyzed Friedel–Crafts arylation of 4‐aryl‐4‐methoxy‐2,5‐cyclohexadienones, which were easily prepared by the phenyliodine(III) diacetate (PIDA)‐mediated oxidation of 4‐arylphenols in methanol, proceeded site‐selectively to form meta‐terphenyl (2,4‐diarylphenol) derivatives in good yields. The subsequent PIDA‐mediated oxidation and iron(III) chloride‐catalyzed Friedel–Crafts arylation of the resulting products gave the corresponding 2,4,6‐triarylphenol derivatives. The present method provides useful highly substituted polyarylated compounds.
83.
Shinichi Kawasaki Masahiro Yamada Kana Kobori Fengzhe Jin Toshikazu Takata 《应用聚合物科学杂志》2010,118(5):2690-2695
The high compatibility of fluorene‐based polyester (FBP‐HX) as a polymer matrix for multiwalled carbon nanotubes (MWCNTs) is discussed. A low surface resistivity due to the fine dispersion of MWCNTs in FBP‐HX and polycarbonate (PC) is reported. With a solution‐casting method, a percolation threshold with the addition of between 0.5 and 1.0 wt % MWCNTs was observed in the MWCNT/PC and MWCNT/FBP‐HX composites. Because of the coverage of FBP‐HX on the MWCNTs, a higher surface resistivity and a higher percolation ratio of the MWCNT/FBP‐HX composites were achieved compared with the values for the MWCNT/PC composites. In the MWCNT/FBP‐HX composites, MWCNTs covered with FBP‐HX were observed by scanning electronic microscopy. Because of the coverage of FBP‐HX on the MWCNTs, FBP‐HX interfered with the electrical pathway between the MWCNTs. The MWCNTs in FBP‐HX were covered with a 5‐nm layer of FBP‐HX, but the MWCNTs in the MWCNT/PC composites were in their naked state. MWCNT/PC sheets demonstrated the specific Raman absorption of the MWCNTs only with the addition of MWCNTs of 1 wt % or above because of the coverage of the surface of the composite sheet by naked MWCNTs. In contrast, MWCNT/FBP‐HX retained the behavior of the matrix resin until a 3 wt % addition of MWCNTs was reached because of the coverage of MWCNTs by the FBP‐HX resin, induced by its high wettability. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
84.
Kensuke Nishioka Tsuyoshi Sueto Masaki Uchida Yasuyuki Ota 《Journal of Electronic Materials》2010,39(6):704-708
Temperature characteristics of an InGaP/InGaAs/Ge triple-junction solar cell were analyzed in detail using an equivalent circuit
calculation. The current–voltage (I–V) characteristics of single-junction solar cells (InGaP, InGaAs, Ge solar cells) were measured at various temperatures. Fitting
of I–V curves between measured and calculated data was carried out, and the diode parameters and temperature exponents of the single-junction
solar cells were extracted. The parameters for each single-junction solar cell were used in the equivalent circuit model for
the triple-junction solar cell, and calculations of solar cell performance were carried out. Measured and calculated results
of the I–V characteristics at various temperatures agreed well. 相似文献
85.
Makoto Sasaki Motoki Inoue Yasuyuki Katada Yuuki Nishida Akiyoshi Taniguchi Sachiko Hiromoto Tetsushi Taguchi 《Science and Technology of Advanced Materials》2012,13(6)
Calcium phosphate was formed on nickel-free high-nitrogen stainless steel (HNS) by chemical solution deposition. The calcium phosphate deposition was enhanced by glutamic acid covalently immobilized on the surface of HNS with trisuccinimidyl citrate as a linker. X-ray diffraction patterns and Fourier transform infrared spectra showed that the material deposited on glutamic acid-immobilized HNS within 24 h was low-crystallinity calcium-deficient carbonate-containing hydroxyapatite (HAp). The biological activity of the resulting HAp-coated HNS was investigated by using a human osteoblast-like MG-63 cell culture. The HAp-coated HNS stimulated the alkaline-phosphate activity of the MG-63 culture after 7 days. Therefore, HAp-coated HNS is suitable for orthopedic devices and soft tissue adhesion materials. 相似文献
86.
Sho Shirakata Katsuhiko Ohkubo Yasuyuki Ishii Tokio Nakada 《Solar Energy Materials & Solar Cells》2009,93(6-7):988-992
Photoluminescence (PL) have been studied on Cu(In,Ga)Se2 (CIGS) thin films, CdS/CIGS and CIGS solar cells, to clarify the carrier recombination process. The chemical-bath deposition (CBD) of the CdS buffer layer on the CIGS thin film leads to (i) the enhancement of near-band-edge PL intensity by a factor of 2–3, (ii) change in energy of the defect-related PL and (iii) the slight change in the decay time. They are related not only to the minimization of the surface recombination but also to the modification of native defects at the Cu-poor surface of CIGS by the occupation of Cd atom at the Cu site. A donor–acceptor pair PL at low-temperature and temperature-dependent PL have been studied. They are discussed in terms of the impurity and defect levels created in the CIGS film during the CBD-CdS process. 相似文献
87.
Reo Etani Takahiro Kataoka Yuichi Nishiyama Yuji Takata 《Journal of Nuclear Science and Technology》2013,50(12):1512-1518
It has been reported that radon inhalation activates antioxidative functions in liver and has an antioxidative effect against hepatopathy similar to that of the antioxidative effects of ascorbic acid (VC) or α-tocopherol (VE). In this study, we examined the combined effects of radon inhalation and antioxidant vitamin administration on acute alcohol-induced hepatopathy in mice. ICR mice were subjected to intraperitoneal (i.p.) administration of alcohol after pretreating with air only (sham) or radon at a concentration of approximately 2000 Bq/m3 for 24 hours and i.p. administration of VC (300 mg/kg body weight) or VE (300 mg/kg body weight). In mice injected with alcohol, the combined radon and antioxidant vitamins treatment significantly decreased the activities of glutamic oxaloacetic transaminase in serum compared to not only the alcohol-administered group (sham group), but also the radon inhalation with alcohol administration group or the vitamin and alcohol administration group. In addition, radon inhalation significantly increased the antioxidant level, in such as the catalase activity and the total glutathione content in liver compared to the sham group. These results suggested that the combined radon and antioxidant vitamin treatment could effectively inhibit alcohol-induced hepatopathy in mice without any antagonizing action. 相似文献
88.
Takashi Masuoka Yasuyuki Takatsu Tomomi Inoue 《Nanoscale and Microscale Thermophysical Engineering》2013,17(4):347-357
An experimental study has been made of the chaotic behavior in the transition to turbulence of flow through porous media consisting of a bank of tubes in a narrow gap. Judging from the examination of the correlation dimension and the maximum Lyapunov exponents, we can identify the chaotic behavior in porous media for Re > ~60. Rapid increase in the maximum Lyapunov exponents was observed for Re > ~300. Also, the spatial distribution of the Lyapunov exponents is discussed. 相似文献
89.
Satoru Goto Yuji Yamamoto Takenao Sugi Takeshi Yasunaga Yasuyuki Ikegami Masatoshi Nakamura 《Electrical Engineering in Japan》2010,170(4):9-17
This paper describes a simulation model for a spray flash desalination system which makes fresh water from sea water by using the temperature difference between warm surface sea water and cool deep sea water. The spray flash desalination system can be modeled by using the energy conservation law and the mass conservation law. Simulation results of the model are compared with the experimental results and show the accuracy of the proposed simulation model. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(4): 9–17, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20975 相似文献
90.
Hiroaki Ishikawa Takehide Nomura Yasuyuki Saito Haruo Kawasaki Atsushi Okamoto Ryuta Hatakenaka 《亚洲传热研究》2011,40(3):269-285
As heat generation in satellites increases, ensuring that they are provided with sufficient radiator panel area is an important problem. Deployable radiators, with radiator panels that are deployed post‐launch in space to increase the satellite's effective radiator panel area of the satellite, are becoming an important thermal control technology. A reservoir embedded loop heat pipe (RELHP) is used in deployable radiators as a heat transport device. A deployable radiator of this type was mounted on the ETS‐VIII satellite, which was launched on December 18, 2006 and injected into a geostationary orbit. The satellite is still operating without any significant issues over two years later. This paper investigates the heat transport characteristics of an RELHP system used in a deployable radiator in a geostationary orbital environment. This system can be successfully started up in a micro gravity environment. We also found that the sub‐cooling region is shorter in a micro gravity environment than in a terrestrial gravity environment, because there is less heat leakage into the reservoir in a micro gravity environment. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library ( wileyonlinelibrary.com/journal/htj ). DOI 10.1002/htj.20346 相似文献