全文获取类型
收费全文 | 1348篇 |
免费 | 25篇 |
国内免费 | 11篇 |
专业分类
电工技术 | 65篇 |
综合类 | 4篇 |
化学工业 | 354篇 |
金属工艺 | 44篇 |
机械仪表 | 24篇 |
建筑科学 | 27篇 |
能源动力 | 53篇 |
轻工业 | 110篇 |
水利工程 | 10篇 |
石油天然气 | 2篇 |
无线电 | 106篇 |
一般工业技术 | 301篇 |
冶金工业 | 166篇 |
原子能技术 | 29篇 |
自动化技术 | 89篇 |
出版年
2023年 | 10篇 |
2022年 | 18篇 |
2021年 | 27篇 |
2020年 | 11篇 |
2019年 | 19篇 |
2018年 | 16篇 |
2017年 | 16篇 |
2016年 | 26篇 |
2015年 | 26篇 |
2014年 | 31篇 |
2013年 | 57篇 |
2012年 | 51篇 |
2011年 | 82篇 |
2010年 | 57篇 |
2009年 | 57篇 |
2008年 | 81篇 |
2007年 | 60篇 |
2006年 | 45篇 |
2005年 | 49篇 |
2004年 | 33篇 |
2003年 | 52篇 |
2002年 | 39篇 |
2001年 | 35篇 |
2000年 | 30篇 |
1999年 | 20篇 |
1998年 | 60篇 |
1997年 | 48篇 |
1996年 | 46篇 |
1995年 | 21篇 |
1994年 | 31篇 |
1993年 | 26篇 |
1992年 | 20篇 |
1991年 | 22篇 |
1990年 | 13篇 |
1989年 | 16篇 |
1988年 | 10篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1985年 | 13篇 |
1984年 | 11篇 |
1983年 | 4篇 |
1982年 | 13篇 |
1981年 | 8篇 |
1980年 | 15篇 |
1979年 | 9篇 |
1977年 | 9篇 |
1976年 | 9篇 |
1975年 | 3篇 |
1973年 | 3篇 |
1969年 | 3篇 |
排序方式: 共有1384条查询结果,搜索用时 0 毫秒
21.
Huiyuan Geng Takahiro Ochi Shogo Suzuki Masaaki Kikuchi Satoru Ito Junqing Guo 《Journal of Electronic Materials》2013,42(7):1999-2005
Bulk multifilled n- and p-type skutterudites with La as the main filler were fabricated using the spark plasma sintering (SPS) method. The thermoelectric properties and thermal stability of these skutterudites were investigated. It was found that the interactions among the filling atoms also play a vital role in reducing the lattice thermal conductivity of the multifilled skutterudites. ZT = 0.76 for p-type La0.8Ba0.01Ga0.1Ti0.1Fe3CoSb12 and ZT = 1.0 for n-type La0.3Ca0.1Al0.1Ga0.1In0.2Co3.75Fe0.25Sb12 skutterudites have been achieved. Furthermore, the differential scanning calorimetry (DSC) results show that there is no skutterudite phase decomposition till 750°C for the La0.8Ba0.01Ga0.1Ti0.1Fe3CoSb12 sample. The thermal stability of the La0.8Ba0.01Ga0.1Ti0.1Fe3CoSb12 skutterudite is greatly improved. Using the developed multifilled skutterudites, the fabricated module with size of 50 mm × 50 mm × 7.6 mm possesses maximum output power of 32 W under the condition of hot/cold sides = 600°C/50°C. 相似文献
22.
Yuta Uenoyama Atsushi Matsuda Kazune Ohashi Koji Ueda Misaki Yokoyama Takuya Kyoutou Kouji Kishi Youichi Takahama Masaaki Nagai Takaaki Ohbayashi Osamu Hotta Hideki Matsuzaki 《International journal of molecular sciences》2022,23(9)
Aberrant glycosylation of IgA1 is involved in the development of IgA nephropathy (IgAN). There are many reports of IgAN markers focusing on the glycoform of IgA1. None have been clinically applied as a routine test. In this study, we established an automated sandwich immunoassay system for detecting aberrant glycosylated IgA1, using Wisteria floribunda agglutinin (WFA) and anti-IgA1 monoclonal antibody. The diagnostic performance as an IgAN marker was evaluated. The usefulness of WFA for immunoassays was investigated by lectin microarray. A reliable standard for quantitative immunoassay measurements was designed by modifying a purified IgA1 substrate. A validation study using multiple serum specimens was performed using the established WFA-antibody sandwich automated immunoassay. Lectin microarray results showed that WFA specifically recognized N-glycans of agglutinated IgA1 in IgAN patients. The constructed IgA1 standard exhibited a wide dynamic range and high reactivity. In the validation study, serum WFA-reactive IgA1 (WFA+-IgA1) differed significantly between healthy control subjects and IgAN patients. The findings indicate that WFA is a suitable lectin that specifically targets abnormal agglutinated IgA1 in serum. We also describe an automated immunoassay system for detecting WFA+-IgA1, focusing on N-glycans. 相似文献
23.
Masaaki Kando Norasage Pattanadech 《IEEJ Transactions on Electrical and Electronic Engineering》2015,10(6):723-725
A new concept of an electrical shunt with two rectangular holes in a copper plate (ESRP) has been developed to be used for measuring a large current with a short‐duration steep wave in a high‐voltage field. The ratio of the input current to the output current is 106, as obtained from a DC voltage test circuit. The electrical shunt has a special configuration. To verify the shunt current ratio of ESRP in a real application, the shunt current was connected to a sphere‐to‐sphere electrode breakdown test circuit with a 10 mm gap to measure the large damping current (8.4 kA) of a DC breakdown voltage. The voltage signal from the shunt was transmitted to excite two light‐emitting diodes (max. 50 mA, 4 V), which were reverse‐connected in series. The light‐emitting diodes operated properly and were illuminated, which validated the capability of the newly designed electrical shunt. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
24.
Tamikuni Komatsu 《应用聚合物科学杂志》1996,59(7):1137-1143
Strong adhesion in the superdrawn polyoxymethylene (POM) fiber/epoxy matrix system was achieved with surface treatments, 2H-hexafluoro-2-propanol (HFP) treatment, and surface phenolation of the fiber. HFP produced micropits for mechanical interlocking with the matrix. Surface phenolation formed active layers leading to interfacial miscibility. © 1996 John Wiley & Sons, Inc. 相似文献
25.
Toshio Fujii Hiroyuki Yoshimoto Naoshi Nagasawa Takayuki Bogaki Yukio Tamai Masaaki Hamachi 《Yeast (Chichester, England)》1996,12(6):593-598
The nucleotide sequences of alcohol acetyltransferase genes isolated from lager brewing yeast, Saccharomyces carlsbergensis have been determined. S. carlsbergensis has one ATF1 gene and another homologous gene, the Lg-ATF1 gene. There was a high degree of homology between the amino acid sequences deduced for the ATF1 protein and the Lg-ATF1 protein (75·7%), but the N-terminal region has a relatively low degree of homology. Southern analysis and contour-clamped homogeneous electric field analysis of Saccharomyces strains suggest that the ATF1 gene is located on chromosome XV in S. cerevisiae and that the Lg-ATF1 gene might originate from the ‘non-S. cerevisiae’ genome of S. carlsbergensis, which is similar to that of S. bayanus and S. pastorianus. The nucleotide sequence data reported in this paper will appear in the DDBJ, EMBL and GenBank data banks with the Accession Numbers D63449 (ATF1) and D63450 (Lg-ATF1). 相似文献
26.
Experimental study of impingement cooling by heat sinks with thin longitudinal fins for LSI packages
This paper reports on the impingement cooling characteristics of a heat sink with thin longitudinal fins of 0.2 mm thickness, which are spaced with a fin-pitch in the range 0.5 mm to 2.0 mm. The air cooling of the heat sink comes from a slot-shaped orifice positioned above the heat-sink center. The breadth of the gap between the fin tops and the inlet orifice is in the range 0 mm to 10 mm. The thermal resistance of the thin longitudinal fins used is about 50% to 57% that of the thick longitudinal fins now in commercial use. The cooling performance of the thin-plate fins is almost the same as that of optimally arranged pin-fins with the same total surface area. A maximum value of six times the heat transfer rate of a single flat plate having the same base area was observed for the thin-plate fins. A comparison of cooling performance between impingement and channel flow systems was conducted. The performance of impingement cooling systems is almost unaffected by the breadth of the gap between the fin tops and the inlet orifice (or, for channel cooling, the upper wall). On the other hand, the performance of channel-cooling systems decreases significantly as the gap widens. © 1997 Scripta Technica, Inc. Heat Trans Jpn Res, 25(7): 449–459, 1996 相似文献
27.
Kadota M Imanaka M Hino S Nanba J Take S Nakazawa H 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2003,44(1):69-72
An analytical method was developed for determination of residual avoparcin in chicken muscle by measuring alpha- and beta-avoparcin, major components of the pharmaceutical preparation avoparcin, using HPLC with UV and amperometric detectors. The analytical HPLC was run on a Cosmosil 5C18-AR column (4.6 mm x 25 cm) with a gradient formed from A: 2.5% acetic acid, 0.01 mol/L sodium heptane sulfonic acid-acetonitrile (88.5:11.5) (pH 4.0) and B: 2.5% acetic acid-acetonitrile (10:90), using UV and amperometric detection (AMD) with glassy-carbon electrode (+900 mV). Avoparcin was extracted from chicken muscle by homogenization with methanol-0.2 mol/L sulfuric acid (6:4) followed by centrifugation after pH adjustment to 4 with 1 mol/L sodium hydroxide. The supernatant was evaporated to dryness, and the residue was dissolved in water. The aqueous layer was adjusted to pH 4 by adding 1 mol/L sodium hydroxide. Then it was purified on a Sep-Pak tC18 plus ENV cartridge. The cartridge was washed with water, and retained substances were eluted with 50% methanol. The eluate was evaporated to dryness under reduced pressure. The residue was dissolved in water and determined by HPLC. Recoveries of avoparcin spiked in chicken muscle were 73.1-88.1% at levels of 2-10 micrograms/g. The detection limits were 0.5 microgram/g (UV) and 0.2 microgram/g (AMD). 相似文献
28.
Tetsuya Nanba Asima Sultana Shouichi Masukawa Masaaki Haneda Junko Uchisawa Akira Obuchi Hideaki Hamada 《Topics in Catalysis》2009,52(13-20):1766-1770
Selective catalytic reduction of NO x by NH3 over Cu–FER and Cu–ZSM-5 in the presence of n-decane and SO2 was investigated. NO x conversion over Cu–ZSM-5 decreased in the presence of n-decane, owing to inhibition of the active sites by coke formation. In contrast, coke formation was negligible over Cu–FER, which maintained its NO x conversion activity even in the presence of decane. Coke formation was negligible over H–ZSM-5 and H–FER supports, which suggests that Cu species were involved in coke formation. Temperature-programmed reduction by H2 and electron spin resonance spectroscopy indicated that [Cu–O–Cu]2+ was probably the Cu species involved in coke formation over Cu–ZSM-5. 相似文献
29.
Masaaki Haneda Ohki Houshito Hiromitsu Takagi Kiyoshi Shinoda Yuunosuke Nakahara Kazumi Hiroe Tadahiro Fujitani Hideaki Hamada 《Topics in Catalysis》2009,52(13-20):1868-1872
The activity of Rh/CeO2 for NO reduction by C3H6 was gradually deceased by mixing with ZrO2 until 68 mol%. Rh supported on CeO2–ZrO2 with higher OSC was found to show lower catalytic activity. High OSC of CeO2–ZrO2 would probably stabilize the surface of Rh in oxidized state, resulting in low activity and low efficiency of C3H6 utilization for NO reduction. In situ FT-IR spectroscopy suggested that mononitrosyl species such as Rh(NO)δ? and Rh(NO)δ+ are reaction intermediates in the NO–C3H6–O2 reaction over Rh/CeO2–ZrO2 catalysts. 相似文献
30.
Hydrogen and carbon dioxide adsorption with tetra‐n‐butyl ammonium semi‐clathrate hydrates for gas separations 下载免费PDF全文
Hiroyuki Komatsu Masaki Ota Yoshiyuki Sato Masaru Watanabe Richard L. Smith Jr. 《American Institute of Chemical Engineers》2015,61(3):992-1003
Gas adsorption rates of H2, CO2, and H2‐CO2 gas mixture (H2/CO2 = 3.4) with tetra‐n‐butyl ammonium salt (bromide, chloride, and fluoride) semi‐clathrate hydrate particles were measured at 269 K to assess their properties for gas separation. Equilibrium gas occupancies in the S‐cages of the particles were in order of (high to low) for hexagonal structure‐I, tetragonal structure‐I, and superlattice of cubic structure‐I structures with the maximum fractional occupancy by CO2 being about 40%. The CO2 diffusion rate depended on the anion size of the salt, which is attributed to distortion of the S‐cage that is close to the molecular size of CO2. Simulations of semi‐clathrate hydrate particles with theory showed that H2/CO2 selectivities could be as high as 36 (3.0 mol% TBAF) and that selectivities for an ideal membrane (3.3 mol% TBAF) could be >100 (269 K, 0.3–4.5 MPa). Semi‐clathrate hydrates have wide application as separation media for gas mixtures. © 2014 American Institute of Chemical Engineers AIChE J, 61: 992–1003, 2015 相似文献