全文获取类型
收费全文 | 443篇 |
免费 | 33篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 155篇 |
金属工艺 | 10篇 |
机械仪表 | 12篇 |
建筑科学 | 32篇 |
矿业工程 | 2篇 |
能源动力 | 33篇 |
轻工业 | 54篇 |
水利工程 | 7篇 |
石油天然气 | 3篇 |
无线电 | 18篇 |
一般工业技术 | 62篇 |
冶金工业 | 21篇 |
原子能技术 | 1篇 |
自动化技术 | 64篇 |
出版年
2024年 | 5篇 |
2023年 | 9篇 |
2022年 | 21篇 |
2021年 | 26篇 |
2020年 | 16篇 |
2019年 | 23篇 |
2018年 | 38篇 |
2017年 | 29篇 |
2016年 | 16篇 |
2015年 | 25篇 |
2014年 | 28篇 |
2013年 | 46篇 |
2012年 | 36篇 |
2011年 | 28篇 |
2010年 | 15篇 |
2009年 | 32篇 |
2008年 | 19篇 |
2007年 | 16篇 |
2006年 | 6篇 |
2005年 | 4篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 5篇 |
1994年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1985年 | 3篇 |
1983年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1970年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有478条查询结果,搜索用时 15 毫秒
31.
32.
33.
We report the mechanical fracture strength and physical properties of fabricated carbons made from pulverized metallurgical coke bonded with coal tar pitch, followed by pyrolysis. Tensile strength from diametral compression of discs ranged from 9.7 ± 1.3 MPa for materials bonded with 13 wt% pitch to 63 ± 7.1 MPa for materials bonded with 40 wt% pitch. Materials made by dry mixing pulverized pitch with coke were comparable with materials made by mixing coke powder with a solution of pitch in toluene. Strength increased with pyrolysis temperature. Pyrolyzed pitch-bonded coke was significantly stronger and lighter than ordinary Portland cement concrete. 相似文献
34.
Evaluation of suspended load transport rate using transport formulas and artificial neural network models (Case study: Chelchay Catchment)* 总被引:2,自引:0,他引:2
HADDADCHI Arman MOVAHEDI Neshat VAHIDI Elham OMID Mohammad Hossein _ DEHGHANI Amir Ahmad 《水动力学研究与进展(B辑)》2013,25(3):459-470
Accurate estimation of sediment load or transport rate is very important to a wide range of water resources projects. This study was undertaken to determine the most appropriate model to predict suspended load in the Chelchay Watershed, northeast of Iran. In total, 59 data series were collected from four gravel bed-rivers and a sand bed river and two depth integrating suspended load samplers to evaluate nine suspended load formulas and feed forward backpropagation Artificial Neural Network (ANN) structures. Although the Chang formula with higher correlation coefficient (r = 0.69) and lower Root Mean Square Error (RMSE = 0.013) is the best suspended load predictor among the nine studied formulas, the ANN models significantly outperform traditional suspended load formulas and show their superior performance for all statistical parameters. Among different ANN structures two models including 4 inputs, 4 hidden and one output neurons, and 4 inputs, 4 and one hidden and one output neurons provide the best simulation with the RMSE values of 0.0009 and 0.001, respectively. 相似文献
35.
Yevgeniy Kim Sanzhar Nurakhayev Ayan Nurkesh Zharylkasyn Zharkinbekov Arman Saparov 《International journal of molecular sciences》2021,22(5)
Cardiovascular disease is the leading cause of mortality and morbidity around the globe, creating a substantial socio-economic burden as a result. Myocardial infarction is a significant contributor to the detrimental impact of cardiovascular disease. The death of cardiomyocytes following myocardial infarction causes an immune response which leads to further destruction of tissue, and subsequently, results in the formation of non-contractile scar tissue. Macrophages have been recognized as important regulators and participants of inflammation and fibrosis following myocardial infarction. Macrophages are generally classified into two distinct groups, namely, classically activated, or M1 macrophages, and alternatively activated, or M2 macrophages. The phenotypic profile of cardiac macrophages, however, is much more diverse and should not be reduced to these two subsets. In this review, we describe the phenotypes and functions of macrophages which are present in the healthy, as well as the infarcted heart, and analyze them with respect to M1 and M2 polarization states. Furthermore, we discuss therapeutic strategies which utilize macrophage polarization towards an anti-inflammatory or reparative phenotype for the treatment of myocardial infarction. 相似文献
36.
Blends of plasticized casein (CA) and poly(vinyl alcohol) (PVA) at various ratios were prepared using the solution‐casting method. The prepared blend solutions were cast onto polystyrene petri plates and bend films were obtained. The characterization of films was performed using Fourier transform infrared spectroscopy, tensile testing, thermogravimetric analysis, contact angle measurements and water vapour permeability. According to spectroscopic analysis, there were interactions between the CA and PVA molecules. The tensile test results showed that the tensile strength of CA increased with increasing PVA content. The flexibility of plasticized CA film increased with the incorporation of PVA. The thermal stability and water vapour barrier properties of plasticized CA improved on blending with PVA. As a result, it was seen that blend films were successfully produced using plasticized CA and PVA with potential for use in biodegradable packaging applications. © 2019 Society of Chemical Industry 相似文献
37.
Stefan Panglisch Arman Kouchaki Shalmani Martin Weber Oliver Gronwald Peter Berg Martin Heijnen Michaela Krug Marcel Koti Andreas Nahrstedt Volker Abetz Ulrich A. Handge Lara Grünig Mathias Ulbricht Inga Stratmann 《化学,工程师,技术》2019,91(8):1162-1167
Within the framework of the MABMEM research project, new high‐performance membranes are being developed for sustainable water management. The performance of the membranes will be evaluated in comparative and standardized fouling tests as well as in terms of the removal of trace impurities on a laboratory scale. Seven candidates are currently being tested in demonstrator trials with real‐water matrix in a waterworks for the direct treatment of dam water without prior coagulation over a period of 6 months. Subsequently, the new membrane materials will be operated with the effluent of a wastewater treatment plant. 相似文献
38.
39.
Multifunctional technical textiles are of great interest both by industry and academia and these products are considered as high value-added products that contribute to the economies of countries. In this study, polyamic acid (PAA) was synthesized through polycondensation of pyromellitic dianhydride (PMDA) and 4,4′-oxydianiline (ODA) in dimethyl acetamide (DMAc) at low temperature. Then, PAA was coated onto woven cotton and polyester fabric by padding technique. Finally, polyimide (PI)-coated multifunctional cotton and polyester fabrics were obtained by an easy coating technique and low-temperature imidization. Thus, low cost, easily accessible and widely used cotton and polyester fabrics were converted to high-performance textile products, which are flame retardant, UV protective, acid resistant, and waterproof. The chemical, thermal, morphological, optical, mechanical, wettability, chemical resistance, and flame retardancy properties of developed fabrics were investigated. Optical results showed that both PI-coated cotton and polyester fabrics are UV-A protective compared to noncoated fabrics. Moreover, PI-coated samples have high contact angles which are 111.43° and 113.40° for PI-coated cotton (PI-c-C) and PI-coated polyester (PI-c-PET), respectively. Young's modulus of PI-c-PET fabrics increased four times more than noncoated polyester fabric. PI coating changed the burning behavior of both cotton and polyester fabrics in a positive way. All the test results showed that these developed multifunctional textile products might find an application in different industrial areas such as automotive, aerospace, protective clothing, and so on due to easy and inexpensive production techniques and also superior properties. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47616. 相似文献
40.