全文获取类型
收费全文 | 769篇 |
免费 | 26篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 10篇 |
综合类 | 3篇 |
化学工业 | 105篇 |
金属工艺 | 7篇 |
机械仪表 | 26篇 |
建筑科学 | 46篇 |
矿业工程 | 4篇 |
能源动力 | 113篇 |
轻工业 | 38篇 |
水利工程 | 7篇 |
石油天然气 | 2篇 |
无线电 | 110篇 |
一般工业技术 | 140篇 |
冶金工业 | 31篇 |
原子能技术 | 2篇 |
自动化技术 | 154篇 |
出版年
2024年 | 1篇 |
2023年 | 9篇 |
2022年 | 12篇 |
2021年 | 21篇 |
2020年 | 14篇 |
2019年 | 13篇 |
2018年 | 26篇 |
2017年 | 32篇 |
2016年 | 36篇 |
2015年 | 27篇 |
2014年 | 34篇 |
2013年 | 100篇 |
2012年 | 56篇 |
2011年 | 61篇 |
2010年 | 47篇 |
2009年 | 70篇 |
2008年 | 57篇 |
2007年 | 50篇 |
2006年 | 29篇 |
2005年 | 17篇 |
2004年 | 20篇 |
2003年 | 13篇 |
2002年 | 11篇 |
2001年 | 9篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有798条查询结果,搜索用时 15 毫秒
31.
Hakan Benzer 《Powder Technology》2005,150(3):145-154
A raw material grinding circuit was modeled using plant data. Samples were collected from around the circuit and, following a crash stop, from inside the mill. The size distributions of the samples were determined down to a few microns. Using the data from inside the mill a modeling approach, based on perfect mixing, was developed. The modelling approach implicitly assumes that the mixture of feed materials broken is homogenous from the breakage point of view. The air classification around the circuit was modeled using the efficiency curve approach. In order to measure the success of the method the circuit performance was predicted by simulation studies while it was operating at different conditions. The results were then compared with the measured data. It is concluded that modeling gives a useful quantitative indication of what may occur in fully air swept mills. 相似文献
32.
Flora W Y Chiu Hakan Bagci Amanda G Fisher Andrew J deMello Katherine S Elvira 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2016,91(1):16-24
Cellular fusion is a key process in many fields ranging from historical gene mapping studies and monoclonal antibody production, through to cell reprogramming. Traditional methodologies for cell fusion rely on the random pairing of different cell types and generally result in low and variable fusion efficiencies. These approaches become particularly limiting where substantial numbers of bespoke one‐to‐one fusions are required, for example, for in‐depth studies of nuclear reprogramming mechanisms. In recent years, microfluidic technologies have proven valuable in creating platforms where the manipulation of single cells is highly efficient, rapid and controllable. These technologies also allow the integration of different experimental steps and characterisation processes into a single platform. Although the application of microfluidic methodologies to cell fusion studies is promising, current technologies that rely on static trapping are limited both in terms of the overall number of fused cells produced and their experimental accessibility. Here we review some of the most exciting breakthroughs in core microfluidic technologies that will allow the creation of integrated platforms for controlled cell fusion at high throughput. © 2015 Society of Chemical Industry 相似文献
33.
Hakan Demiral ?lknur DemiralBelgin Karabacako?lu Fatma Tümsek 《Chemical Engineering Research and Design》2011,89(2):206-213
Activated carbons were produced from olive bagasse and their characteristics were investigated. Olive bagasse was first carbonized at 500 °C in N2 atmosphere. Then, the obtained chars were activated with steam. The effects of activation temperature and duration were examined. The resultant activated carbons were characterized by measuring their porosities and pore size distributions. The activated carbons produced had the BET surface areas ranging from 523 to 1106 m2/g. The total pore volume was increased from 0.2981 to 0.6067 cm3/g. Adsorption capacity was demonstrated by the iodine numbers. The surface chemical characteristics of activated carbons were determined by FTIR spectroscopic method and Boehm's titration method. The microstructure of the activated carbons prepared was examined by scanning electron microscopy (SEM). The experimental data was proved that the properties of activated carbons depend on the final temperature of the process and duration of treatment at the final temperature. 相似文献
34.
Utilization of Electrospun Polystyrene Membranes as a Preliminary Step for Rapid Diagnosis 下载免费PDF全文
Recent advances in clinical practice drive deoxyribonucleic acid (DNA) as an important class of biomarker. Monitoring the change in their concentration suggests the initiation and/or progression of various disorders. However, low quantity of DNA biomarkers in body fluids requires a delicate isolation methodology that provides efficient separation and easy handling. This study describes a newer‐generation separation technology relying on electrospun fibers of sub‐micrometer diameter of a commodity polymer for DNA biomarkers in simulative serum. Fibrous polystyrene membranes are prepared by electrospinning and they are subjected to post‐modification with Au. The composite membranes may provide a convenient environment for the removal of bovine serum albumin (BSA) from BSA and DNA mixtures. The eluent can be used as an efficient tool for detection of DNA biomarkers associated with diagnosis of numerous life‐threatening diseases.
35.
Meryem Koruyucu Fehmi Saltan Gökhan Kök Hakan Akat Yeşim Salman 《Iranian Polymer Journal》2016,25(5):455-463
The present study describes the synthesis and characterizations of polymerizable vinyl sugars. Glucose, mannose, galactose and fructose are abundant and sustainable natural compounds. As it is not possible to make many derivatives of sugars without using protective groups, first of all, diacetone derivatives [diacetone-d-glucose (1), diacetone-d-mannose (2), diacetone-d-galactose (3) and diacetone-d-fructose (4)] were synthesized according to the literature as starting compounds. The remaining free hydroxyl groups on C-3 (diacetone glucose), C-6 (diacetone galactose), C-1 (diacetone fructose) and C-1 (diacetone mannose), were reacted with epichlorohydrin (1-chloro-2,3-epoxypropane) to produce then “-O-(2′,3′-epoxypropane-1′-yl)” ether derivatives (5, 6, 7, and 8) which are epoxy sugars in the basic medium. Next, the epoxy rings of the ethers (5, 6, 7, and 8) were opened with methacrylic acid in DMF to produce new sugar based methacrylates (9, 10, 11, and 12). Finally, free radical polymerization of these sugar based methacrylate monomers was performed, producing related polymers (13, 14, 15 and 16). The polymerizations were carried out using AIBN as an initiator at 70 °C in DMF. All the products were characterized by FTIR, 1HNMR and 13CNMR techniques. Thermal properties of all polymers were investigated by TG, DTG and DSC. The data obtained has suggested that thermal stability of the synthesized polymers has changed with the structure of the sugar and increase in molecular weight. 相似文献
36.
Preparation of laurel oil alkanolamide from laurel oil 总被引:1,自引:1,他引:1
Hakan Kolancilar 《Journal of the American Oil Chemists' Society》2004,81(6):597-598
A low-temperature synthesis of laurel oil alkanolamides directly from laurel oil and ethanolamine was carried out in essentially
quantitative yields. The ethanolamine/laurel oil molar ratio used was 10∶1. Even though amine served as a catalyst in the
reaction, we used sodium methoxide at a ratio of 0.2–2% as a second catalyst. The reaction was complete in 1–9 h at room temperature.
The identity of the amide was confirmed by IR and 13C NMR spectroscopy. 相似文献
37.
Summary
2,5-Dihydro-2,5-dimethoxyfuran (DHMF) was polymerized via constant current electrolysis (CCE), in CH3CN-NaClO4 solvent-electrolyte couple. Poly(DHMF) was obtained from the anolyte. The effect of current density, temperature, monomer and electrolyte concentrations on the polymer yield have been examined. The apparent activation energy for CCE of DHMF was found to be 37.2 kj/mol. The FTIR and 1H-NMR analyses show that DHMF polymerizes by a ring opening. Molecular weight of poly(DHMF) was found by using cryoscopy. 相似文献
38.
Non-destructive determination of residual stress state in steel weldments by Magnetic Barkhausen Noise technique 总被引:2,自引:0,他引:2
The purpose of this study is non-destructive determination of residual stresses in the welded steel plates by Magnetic Barkhausen Noise (MBN) technique. A MBN-stress calibration set-up and a residual stress measurement system with scanning ability were developed. To control the accuracy and the effectiveness of the developed system and procedure, various MBN measurements were carried out. The MBN results were verified by the hole-drilling method. Microstructural investigation and hardness measurements were also conducted. It was concluded that if the calibration procedure including the effect of microstructure is appropriate then MBN is a very promising method for non-destructive, fast and accurate prediction of residual stresses in the welded plates. 相似文献
39.
The efficiency of ozone treatment for degradation of the mycotoxin patulin in the presence of various metal ions was evaluated in model systems. An initial patulin concentration of 250 μg/L was ozonated and residual ozone concentration was about 0.17±0.01 mg/L at the end of the experiment. Patulin showed a weak resistance to ozone, because up to 98% of this toxin was oxidized in only one minute. Degradation rates in the presence of calcium, aluminum, copper and zinc were almost the same in the absence of these metals. However, degradation of patulin was reduced from 98 to 37% when the concentration of manganese increased from 0 to 3 mg/L. Patulin was almost completely degraded in the absence of iron, while the degradation was only 8.5% in the presence of 0.5 mg/L of iron. These results have revealed that manganese and iron significantly reduce the detoxification of patulin by ozone. Agents such as ethylenediaminetetraacetic acid and sodium polyphosphate effectively chelated iron and increased the degradation rate of patulin. None of the tested agents were able to chelate manganese and to enhance patulin degradation by ozone. 相似文献
40.
Hakan Aşkun Basri Gülbakan Ömür Çelikbıçak Cengiz Uzun Olgun Güven Bekir Salih 《应用聚合物科学杂志》2008,107(4):2714-2722
Poly(styrene-divinylbenzene), PS-DVB, microbeads were modified with 8-hydroxyquinoline (8-HQ) following nitration, reduction of NO2 to NH2, and conversion of NH2 to diazonium salt. Characterization of pristine, NO2, NH2, NN+Cl−, and 8-QH functional groups modified microbeads was made by Fourier transform-infrared spectrometry (FTIR) and porosimetry. Total reflectron-X-ray florescence spectrometer (TXRF) was used to test the affinity of the 8-HQ modified microbeads to toxic metal ions. 8-HQ-modified microbeads were used to examine the adsorption capacity, recovery, preconcentration, and the matrix elimination efficiency for Pb(II), Cd(II), Ni(II), and Co(II) ions as a function of changing pH, initial metal-ion concentrations, and also equilibrium adsorption time of the studied metal ions. Preconcentration factors for the studied toxic metal ions were found to be more than 500-fold and recovery between 93.8% and 100.6%. Ultratrace toxic metal-ion concentrations in sea water were determined easily by using modified microbeads. Reference sea-water sample was used for the validation of the method, and it was found that recovery, preconcentration, and the matrix elimination were performed perfectly. For the desorption of the toxic metal ions, 3M of HNO3 was used and desorption ratio shown to be more than 96%. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献