全文获取类型
收费全文 | 288篇 |
免费 | 32篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 7篇 |
综合类 | 5篇 |
化学工业 | 99篇 |
金属工艺 | 17篇 |
机械仪表 | 7篇 |
建筑科学 | 7篇 |
矿业工程 | 1篇 |
能源动力 | 13篇 |
轻工业 | 24篇 |
水利工程 | 6篇 |
石油天然气 | 1篇 |
无线电 | 33篇 |
一般工业技术 | 65篇 |
冶金工业 | 8篇 |
原子能技术 | 1篇 |
自动化技术 | 28篇 |
出版年
2023年 | 9篇 |
2022年 | 3篇 |
2021年 | 11篇 |
2020年 | 19篇 |
2019年 | 21篇 |
2018年 | 27篇 |
2017年 | 26篇 |
2016年 | 18篇 |
2015年 | 17篇 |
2014年 | 24篇 |
2013年 | 37篇 |
2012年 | 22篇 |
2011年 | 23篇 |
2010年 | 12篇 |
2009年 | 11篇 |
2008年 | 8篇 |
2007年 | 8篇 |
2006年 | 3篇 |
2004年 | 2篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 5篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1986年 | 1篇 |
排序方式: 共有322条查询结果,搜索用时 46 毫秒
1.
Mozhgan Shahmirzaee Ahmad Iran Nejhad Amir Masoud Arabi 《Particulate Science and Technology》2019,37(1):110-117
ZnAl2O4 and ZnO nanostructure particles and in situ crystallization of zinc aluminate and zinc oxide coating layers on sintered α-Al2O3 and γ-Al2O3 granules by the microwave-assisted combustion method were investigated. For powders, the effects of solution pH value and for coated samples the influence of support type on the structure, microstructure, and photocatalytic activity of powders were studied. Results showed that variation of synthesis pH value caused to considerable change in agglomeration, specific surface area, obtaining up to 88 and 92% yields for zinc aluminate and zinc oxide nanoparticles, respectively. γ-alumina granules were more appropriate supports than the α-alumina ones because of the better photocatalytic activities and lower extent of the attritions for both zinc aluminate and zinc oxide coating layers. 相似文献
2.
Zahra Ghahramani Amir Masoud Arabi Mahdi Shafiee Afarani Mohammad Mahdavian 《International Journal of Applied Ceramic Technology》2020,17(3):1514-1521
In this study, combustion synthesis of cerium oxide nanoparticles was reported using cerium nitrate hexahydrate as starting material as well as urea, glycine, glucose, and citric acid as fuels. The influence of fuel type on structure, microstructure, band gap, and corrosion inhibition was investigated. X-ray diffraction (XRD) patterns and scanning electron microscopy micrographs showed that CeO2 nanoparticles with different morphologies were obtained depending on the fuel type. Microstructural changes from unreacted gel to sponge-like morphologies were resulted by varying the fuel type from urea, glycine, and glucose to citric acid. In addition to Ce–O bonds, Fourier transform infrared analysis showed carbon bonds of carbonaceous compositions from incomplete combustion which were declined during combustion reaction. Furthermore, corrosion analyses showed that samples synthesized using urea fuel released the most Ce+4 ions and could have better protection than other samples. 相似文献
3.
4.
Keyvanpour Mohammad Reza Khanbani Neda Aliniya Zahra 《Multimedia Tools and Applications》2021,80(9):13879-13910
Multimedia Tools and Applications - Auto understanding of human activities in video is an increasing necessity in some application realms. The existing methods for human’s activity... 相似文献
5.
The Tunable Porous Structure of Gelatin–Bioglass Nanocomposite Scaffolds for Bone Tissue Engineering Applications: Physicochemical,Mechanical, and In Vitro Properties 下载免费PDF全文
Unidirectional freeze‐casting method is used to fabricate gelatin–bioglass nanoparticles (BGNPs) scaffolds. Transmission electron microscopy (TEM) images show that sol–gel prepared BGNPs are distributed throughout the scaffold with diameters of less than 10 nm. Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetric are used to evaluate the physicochemical properties of BGNPs. Scanning electron microscopy (SEM) micrographs present an oriented porous structure and a homogeneous distribution of BGNPs in the gelatin matrix. The lamellar‐type structure indicates an improvement of mechanical strength and absorption capacity of the scaffolds. Increasing the concentration of BGNPs from 0 to 50 wt% have no noticeable effect on pore orientation, but decreases porosity and pore size distribution. Increase in BGNPs content improves the compressive strength. The absorption and biodegradation rate reduces with augmentation in BGNPs concentration. Bioactivity is evaluated through apatite formation after immersion of the nanocomposites in simulated body fluid and is verified by SEM–energy‐dispersive X‐ray spectroscopy (EDS), an element map analysis, X‐ray powder diffractometer, and FTIR spectrum. SEM images and methyl thiazolyl tetrazolium assay confirm the biocompatibility of scaffolds and the supportive behavior of nanocomposites in cellular spreading. The results show that gelatin–(30 wt%)bioglass nanocomposites have incipient physicochemical and biological properties. 相似文献
6.
Neda Stoehr Benjamin Baudrit Edmund Haberstroh Michael Nase Peter Heidemeyer Martin Bastian 《应用聚合物科学杂志》2014,131(12)
The objectives of the presented work were to investigate films based on polylactic acid (PLA) and polyethylene glycol (PEG) in order to improve ductility and weldability of PLA films. The effect of plasticizer amount on the thermal, rheological, and mechanical properties of PLA plasticized films was investigated. The PEG content does affect the glass transition and the cold crystallization temperature of PLA in blends, while the melting temperature was not affected by the addition of PEG. The complex viscosity of the neat PLA granules and of plasticized films showed strong temperature and angular velocity dependence. The Young's modulus and tensile strength of plasticized films were improved with increasing plasticizer concentration, while the elongation at break stays rather constant. Plasticized PLA films were furthermore heat welded. These investigations showed that plasticized PLA films can be welded by heat welding. The obtained weld strength is strongly depending on the PEG amount as well as on selected welding parameters. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40394. 相似文献
7.
Back Cover: Hydrophobic Triaryl‐Substituted β‐Lactams as Activity‐Based Probes for Profiling Eukaryotic Enzymes and Host–Pathogen Interactions (ChemBioChem 15/2014) 下载免费PDF全文
8.
Dandan Li Neda Kordalivand Marieke F. Fransen Ferry Ossendorp Koen Raemdonck Tina Vermonden Wim E. Hennink Cornelus F. van Nostrum 《Advanced functional materials》2015,25(20):2993-3003
Targeting of antigens to dendritic cells (DCs) to induce strong cellular immune response can be established by loading in a nano‐sized carrier and keeping the antigen associated with the particles until they are internalized by DCs. In the present study, a model antigen (ovalbumin, OVA) is immobilized in cationic dextran nanogels via disulfide bonds. These bonds are stable in the extracellular environment but are reduced in the cytosol of DCs due to the presence of glutathione. Reversible immobilization of OVA in the nanogels is demonstrated by the fact that hardly any release of the protein occurred at pH 7 in the absence of glutathione, whereas rapid release of OVA occurs once the nanogels are incubated in buffer with glutathione. Furthermore, these OVA conjugated nanogels show intracellular release of the antigen in DCs and boost the MHC class I antigen presentation, demonstrating the feasibility of this concept for the aimed intracellular antigen delivery. 相似文献
9.
Cationic Nanogels: Reduction‐Sensitive Dextran Nanogels Aimed for Intracellular Delivery of Antigens (Adv. Funct. Mater. 20/2015) 下载免费PDF全文
10.
Synthesis,characterization, rheological and thermal behavior of metallocene ethylene − norbornene copolymers with low norbornene content using pentafluorophenol modified methylaluminoxane 下载免费PDF全文
Ethylene ? norbornene copolymers were synthesized using rac‐ethylene bis(indenyl) zirconium dichloride/pentafluorophenol modified methylaluminoxane. First, the effect of using a modifier in combination with a low ratio of Al/Zr on the catalyst activity and co‐monomer incorporation was studied. The results of copolymerization reveal a 20% co‐monomer incorporation improvement and a rise of activity by 2‐fold in the presence of the modifier. Rheological measurements show a higher molecular weight in copolymers synthesized using modified methylaluminoxane. The alternative and dyad block microstructures of copolymers become possible in the case of a norbornene content of more than 14 mol%. Second, the effect of co‐monomer content on the rheological and thermal behavior of the synthesized copolymers was investigated. The results of the rheological study indicate a lower molecular weight in samples containing a higher norbornene content. Dynamic mechanical thermal analysis confirms the influence of different microstructures on the glass transition temperature. The crystal structure of copolymers having a higher molecular weight is emphasized using wide angle X‐ray scattering and DSC even with a greater incorporation of norbornene. © 2015 Society of Chemical Industry 相似文献