全文获取类型
收费全文 | 589468篇 |
免费 | 21732篇 |
国内免费 | 1516篇 |
专业分类
电工技术 | 10459篇 |
综合类 | 562篇 |
化学工业 | 100091篇 |
金属工艺 | 20750篇 |
机械仪表 | 16344篇 |
建筑科学 | 15225篇 |
矿业工程 | 2350篇 |
能源动力 | 16110篇 |
轻工业 | 57854篇 |
水利工程 | 5707篇 |
石油天然气 | 9520篇 |
武器工业 | 44篇 |
无线电 | 67190篇 |
一般工业技术 | 116146篇 |
冶金工业 | 111310篇 |
原子能技术 | 10752篇 |
自动化技术 | 52302篇 |
出版年
2022年 | 3885篇 |
2021年 | 6157篇 |
2020年 | 5463篇 |
2019年 | 8223篇 |
2018年 | 11490篇 |
2017年 | 11494篇 |
2016年 | 12393篇 |
2015年 | 9695篇 |
2014年 | 13647篇 |
2013年 | 30798篇 |
2012年 | 18781篇 |
2011年 | 24067篇 |
2010年 | 19541篇 |
2009年 | 21268篇 |
2008年 | 21144篇 |
2007年 | 20425篇 |
2006年 | 17746篇 |
2005年 | 16175篇 |
2004年 | 15476篇 |
2003年 | 15112篇 |
2002年 | 14276篇 |
2001年 | 14126篇 |
2000年 | 13168篇 |
1999年 | 13417篇 |
1998年 | 34882篇 |
1997年 | 24294篇 |
1996年 | 18421篇 |
1995年 | 13615篇 |
1994年 | 11779篇 |
1993年 | 11514篇 |
1992年 | 8149篇 |
1991年 | 7620篇 |
1990年 | 7415篇 |
1989年 | 7198篇 |
1988年 | 6639篇 |
1987年 | 5912篇 |
1986年 | 5793篇 |
1985年 | 6439篇 |
1984年 | 6033篇 |
1983年 | 5279篇 |
1982年 | 5033篇 |
1981年 | 5095篇 |
1980年 | 4852篇 |
1979年 | 4704篇 |
1978年 | 4496篇 |
1977年 | 5598篇 |
1976年 | 7502篇 |
1975年 | 3870篇 |
1974年 | 3599篇 |
1973年 | 3735篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Kruglikov S. S. Zagorskii D. L. Kolesnikov V. A. Doludenko I. M. Bedin S. A. 《Theoretical Foundations of Chemical Engineering》2021,55(5):942-951
Theoretical Foundations of Chemical Engineering - The effect of the electrolyte composition, mass-transfer conditions, pore diameter, interpore distance, and electric parameters on the formation of... 相似文献
62.
Vasanthapriya R. Neelakandeswari N. Uthayarani K. Chitra M. 《Journal of Inorganic and Organometallic Polymers and Materials》2021,31(11):4272-4280
Journal of Inorganic and Organometallic Polymers and Materials - This paper reports the performance of alizarin based SnO2 dye-sensitized solar cells. A novel template assisted method has been... 相似文献
63.
Applied Composite Materials - Determining the impact behavior of adhesive joints allows the designing of high-strength joints. Therefore, the dynamic behavior of adhesive joints has recently become... 相似文献
64.
Ebrahim A. Mahdy Khadega M. Sahbal Hanan H. Beherei Yasser K. Abdel-Monem 《Ceramics International》2021,47(5):6251-6261
A new TiO2-containing bioactive glass and glass-ceramics based on 50SiO2-(45-X)CaO-(XTiO2)-5P2O5 system was designed using a sol–gel technique (where X = 5, 7.5 and 10 wt %). The roles of the crystallization behavior and physicochemical characteristics of the designed glass and glass-ceramics which were played in the introduction of TiO2 substitutions were investigated. Moreover, cell proliferation and differentiation were evaluated against human osteosarcoma cells (Saos-2). The TiO2/CaO replacements led to the formation of a stronger glass structure and thus increased thermal parameters and the chemical stabilization of the designed materials. The FTIR data confirmed the existence of Ti within the glass and glass-ceramics samples, and no remarkable effect on their chemical integrity was observed. The XRD patterns indicated that calcium-containing minerals, including Ca2SiO4,Ca3(PO4)2, Ca(Ti,Si)O5, CaTiSiO5, and Ca15(PO4)2·(SiO4)6 phases were developed as a role of structure/texture under the applied heat-treatment. The results of the cytotoxicity test proved that a safe sample dose is 12–50 μg/ml, at which cell viability is ≥ 85%. The cell differentiation determined by ALP test proved the superiority of glass-ceramics compared with their native glasses. Therefore, the obtained materials could be safely used as novel biocompatible materials for the regeneration of bone tissue. 相似文献
65.
T.V. Vakalova L.P. Devyashina Sh.M. Sharafeev N.P. Sergeev 《Ceramics International》2021,47(11):15282-15292
One of the drawbacks of fusible clays is the narrow sintering interval due to a sharp increase in the amount of iron-silicate melt at a temperature of 1000–1100 °C, which hardens in the form of a glass phase upon cooling. This leads to a relatively low mechanical strength of the calcined samples and causes the danger of melting the granular material surface from such clays during the firing process. To increase the strength of samples of fusible clays, the influence of diabase and granitoid rocks was considered. It was found that the strengthening effect of diabase and granitoid rock additives in an amount of 20–50% in a mixture with fusible clay is due to an increase of total content of the crystalline phase (mullite, cristobalite and residual quartz) from 18–20% in clays without additives to 22–28 % - in mixtures with diabase and to 28–34% - with granitoid additives) at a temperature of 1050–1100 °C. This increase is due to the activation of synthesis processes of secondary mullite and crystallization from alkali-rich feldspar melt of amorphous silica, released from the structure of clay minerals. The established influence of the igneous rocks used made it possible to develop compositions and propose process flow sheet for producing aluminosilicate proppants based on fusible clays. The use of granitoid and diabase rocks in an amount of 20–70% with fusible clays produces lightweight aluminosilicate proppants with bulk density of 1.40–1.46 g/cm3 at temperature range of 1050–1100 °C, which can endure destructive pressures up to 34.5–52 MPa. 相似文献
66.
Moustapha Moussa Amudhan Ponrajan Osvaldo H. Campanella Martin R. Okos Mario M. Martinez Bruce R. Hamaker 《International Journal of Food Science & Technology》2022,57(7):4594-4601
Traditional West African pearl millet couscous products are popular; however, their preparation is laborious, time-consuming and energy-demanding, involving agglomeration, steaming, drying and sieving steps. In this study, a process was developed to produce millet couscous using a high pressure, high temperature and low-cost single-screw extruder. The innovation was to directly process the cooked low-moisture extrudate to a couscous product by drying and milling to the appropriate particle size (ranging between 1 and 2 mm). Throughput for the traditional process as prepared for commercial sale is 50 kg per day, but with the same amount of labour, the extrusion process yields ~350 kg per day. A consumer sensory study held in Niamey (Niger) showed that the extruded millet couscous was comparable to traditional couscous, though this was dependent on selection of the proper millet variety. This novel extrusion process could stimulate small- to medium-scale manufacturing of couscous and couscous-type products in West Africa. 相似文献
67.
A. Kathalingam S. Valanarasu Tansir Ahamad Saad M. Alshehri Hyun-Seok Kim 《Ceramics International》2021,47(6):7608-7616
Herein, we report the photosensing property of CdS thin films. CdS thin films were coated onto glass substrates via a spray pyrolysis method using different spray pressures. Prepared films were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and optical and photoluminescence spectroscopy. XRD analysis demonstrated the growth of crystalline CdS films with crystallite sizes varying from 26 to 29 nm depending on the pressure. The SEM and EDAX analyses revealed nearly-stoichiometric CdS films with smooth surfaces and slight variation in grain morphology due to pressure changes. Optical measurements showed a direct bandgap varying from 2.37 eV to 2.42 eV due to pressure changes. A photodetector was also fabricated using the grown CdS films; the fabricated photodetector exhibited good performance depending on the spray pressure. A spray pressure of 1.5 GPa resulted in high photoresponsivity and external quantum efficiency. 相似文献
68.
Golubev N. V. Ignat’eva E. S. Maurus A. A. Ziyatdinova M. Z. Lopatina E. V. Lorenzi R. Paleari A. Sigaev V. N. 《Glass and Ceramics》2021,77(11-12):415-418
Glass and Ceramics - The influence of Al2O3 as an additive and the heat-treatment regime on the luminescence spectra of gallate glass-ceramics was investigated. It is shown that its luminescence... 相似文献
69.
Ana Clara Sabbione Santiago Suárez María Cristina Añón Adriana Scilingo 《International Journal of Food Science & Technology》2019,54(5):1506-1513
In this study, amaranth flour was used as an ingredient to prepare gluten-free cookies. The production process and attributes of amaranth cookies were characterised, and the potential use of amaranth flour as a functional ingredient was analysed. Cookies exhibited a non-uniform reddish brown colour and a cookie factor ratio of 4.5 ± 0.6. Storage studies indicated that after 3 weeks at room temperature cookies presented slight variations in the texture. Simulated gastrointestinal digestion of this product was able to release peptides capable of exerting potential antithrombotic and antihypertensive activities, IC50 values of 0.22 ± 0.04 and 0.23 ± 0.03 mg mL−1 protein, respectively. This work demonstrates for the first time that food made with amaranth flour exerts potential antithrombotic and antihypertensive activity. In conclusion, these amaranth cookies could be an alternative way of incorporating potentially health beneficial products for people who choose a conscious diet, including coeliac or vegan consumers. 相似文献
70.
Fluorescence‐Activated Cell Sorters: Standing Surface Acoustic Wave (SSAW)‐Based Fluorescence‐Activated Cell Sorter (Small 40/2018)
下载免费PDF全文
![点击此处可从《Small (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)