全文获取类型
收费全文 | 1001篇 |
免费 | 35篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 28篇 |
化学工业 | 190篇 |
金属工艺 | 30篇 |
机械仪表 | 29篇 |
建筑科学 | 7篇 |
能源动力 | 28篇 |
轻工业 | 122篇 |
水利工程 | 5篇 |
石油天然气 | 5篇 |
无线电 | 231篇 |
一般工业技术 | 202篇 |
冶金工业 | 94篇 |
原子能技术 | 5篇 |
自动化技术 | 65篇 |
出版年
2023年 | 5篇 |
2022年 | 16篇 |
2021年 | 38篇 |
2020年 | 22篇 |
2019年 | 24篇 |
2018年 | 29篇 |
2017年 | 25篇 |
2016年 | 24篇 |
2015年 | 14篇 |
2014年 | 34篇 |
2013年 | 53篇 |
2012年 | 25篇 |
2011年 | 45篇 |
2010年 | 47篇 |
2009年 | 28篇 |
2008年 | 31篇 |
2007年 | 21篇 |
2006年 | 18篇 |
2005年 | 25篇 |
2004年 | 27篇 |
2003年 | 14篇 |
2002年 | 12篇 |
2001年 | 16篇 |
2000年 | 19篇 |
1999年 | 19篇 |
1998年 | 31篇 |
1997年 | 32篇 |
1996年 | 18篇 |
1995年 | 35篇 |
1994年 | 31篇 |
1993年 | 28篇 |
1992年 | 22篇 |
1991年 | 24篇 |
1990年 | 24篇 |
1989年 | 23篇 |
1988年 | 18篇 |
1987年 | 9篇 |
1986年 | 11篇 |
1985年 | 9篇 |
1984年 | 10篇 |
1983年 | 7篇 |
1982年 | 9篇 |
1981年 | 9篇 |
1980年 | 13篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1976年 | 13篇 |
1975年 | 6篇 |
1966年 | 2篇 |
排序方式: 共有1041条查询结果,搜索用时 46 毫秒
11.
Studies on the effect of nitrogen plasma on morphology and textile properties of mulberry silk fibers and fabrics have been conducted. The changes in the morphological structure have been monitored by transmission electron microscopy, X-ray diffraction, and internal reflection infrared spectroscopy. The changes in some of textile properties such as wettability, drying rate, and crease recovery owing to plasma treatment have also been investigated. It has been found that the surface of mulberry silk gets etched away, even affecting the crystalline region. This behavior is opposite to our findings on tassar silk. Therefore, an explanation of this differential behavior of mulberry with tasar on the basis of amino acid linkages vis-à-vis bonding, wettability, drying rate, and water retention capacity has been attempted. These results have been used to arrive at an understanding of internal structure of mulberry. 相似文献
12.
Undoped and Te-doped gallium antimonide (GaSb) layers have been grown on GaSb bulk substrates by the liquid phase epitaxial
technique from Ga-rich and Sb-rich melts. The nucleation morphology of the grown layers has been studied as a function of
growth temperature and substrate orientation. MOS structures have been fabricated on the epilayers to evaluate the native
defect content in the grown layers from theC-V characteristics. Layers grown from antimony rich melts always exhibitp-type conductivity. In contrast, a type conversion fromp- ton- was observed in layers grown from gallium rich melts below 400 C. The electron mobility of undopedn-type layers grown from Ga-rich melts and tellurium doped layers grown from Sb- and Ga-rich solutions has been evaluated.
Paper presented at the poster session of MRSI AGM VI. Kharagpur. 1995 相似文献
13.
14.
Atomic layer epitaxy or ALE has proven to be useful for the growth of epitaxial layers of high uniformity, good quality, and
well-controlled thickness. In this study, we have carried out in-situ monitoring during the atmospheric pressure ALE of CdTe on GaAs (100) substrates using spectroscopic ellipsometry (SE). The
susceptor temperature, reactant partial pressures, as well as the flow and flush duration for each precursor are crucial process
variables for ALE growth. Growth was carried out for 20–25 cycles under different sets of these process conditions during
the experiment and in-situ SE was used to verify the presence of layer-by-layer growth, which enabled the quick determination of the process window.
We observed ALE growth of CdTe at 300°C, supporting the explanation that the growth of CdTe occurs via a surface catalyzed
decomposition of the Te precursor di-isopropyltelluride (DIPTe). Investigation of ALE mode growth behavior for different susceptor
temperatures and DIPTe flush times indicated that the growth was limited by competition between desorption and reaction of
the adsorbed DIPTe species on the Cd terminated surface. 相似文献
15.
The influence of black pepper (Piper nigrum L.) and its active principle, piperine on the secretion and composition of bile was investigated in the rat. They were administered by gavage (black pepper at 250 or 500 mg and piperine at 12.5 or 25 mg/kg body wt.) or fed in the diet for 4 weeks (black pepper at 0.2 and 0.4%, piperine at 0.01 and 0.02%). The lower dose by gavage of black pepper caused an increase in bile solids while with other treatments bile secretion or dry matter in bile was not changed. Dietary feeding of black pepper caused an increase in bile flow with a concomitant decrease in bile solids -- a hydrocholagoguic effect. Cholesterol and bile acid output were not affected by black pepper or piperine at either level irrespective of the mode of administration; in contrast, the secretion of uronic acids in bile was enhanced by both levels of pepper as also of piperine indicating possible excretion of some of the components of black pepper or of piperine as glucuronides. 相似文献
16.
R Venkataraghavan K M Satyalakshmi K S R K Rao A K Sreedhar M S Hegde H L Bhat 《Bulletin of Materials Science》1996,19(1):123-129
Single crystalline oriented films of indium antimonide have been grown on cadmium telluride substrates by the pulsed laser
deposition technique. The films were (111) oriented which is the substrate orientation. The composition of the grown films
were found to deviate from that of the target owing to loss of antimony during evaporation. This deviation from stoichiometry
led to film-substrate reaction, resulting in mixed interface. The antimony deficiency in the films were controlled by correcting
the stoichiometry, which led to avoiding mixed interfaces. The stoichiometric films showed good surface morphology and well
defined sharp interfaces. The IR transmission spectrum showed sharp band to band absorption and effective detection in the
MWIR.
Paper presented at the poster session of MRSI AGM VI, Kharagpur, 1995 相似文献
17.
The immunosuppressive agent FK 506 is widely used in liver transplant patients. Neurotoxicity is a major complication of its use. We report progressive and irreversible neurologic complications occurring in a 39-year-old woman who underwent liver transplantation and was treated with FK 506. Neuropathologic examination revealed multiple vasculitic lesions. The possibility of an FK 506-mediated toxic effect on the cerebral vessels is suggested. 相似文献
18.
Khanapure Sharanabasappa Pore Dattaprasad Jagadale Megha Patil Vaishali Rashinkar Gajanan 《Catalysis Letters》2021,151(8):2237-2249
Catalysis Letters - A novel silica supported ferrocene appended N-heterocyclic carbene-palladium complex (SilFemBenzNHC@Pd) has been prepared and characterized by using fourier transform infrared... 相似文献
19.
20.
R. S. Veerapur K. B. Gudasi M. B. Patil V. Ramesh Babu S. D. Bhat M. Sairam T. M. Aminabhavi 《应用聚合物科学杂志》2006,101(5):3324-3329
Interpenetrating polymeric network (IPN) membranes of sodium alginate (NaAlg) and various amounts of poly(hydroxyethylmethacrylate) (PHEMA) have been prepared and tested for the pervaporation dehydration of ethanol and tetrahydrofuran (THF). The presence of hydrophilic PHEMA in the IPN matrix was found to be responsible for increase in membrane selectivity to water. NaAlg–PHEMA IPN membrane containing 20 wt % of PHEMA exhibited a selectivity of 571 to water for the water–ethanol mixture and 857 for water–THF mixture. These data are much better than those observed for the pristine NaAlg membrane. However, flux of the IPN membranes was smaller than that of pristine NaAlg membrane. Comparatively higher flux values were observed for water–THF mixture than for water–ethanol mixture. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3324–3329, 2006 相似文献