全文获取类型
收费全文 | 785篇 |
免费 | 91篇 |
国内免费 | 42篇 |
专业分类
电工技术 | 2篇 |
综合类 | 34篇 |
化学工业 | 384篇 |
金属工艺 | 41篇 |
机械仪表 | 30篇 |
建筑科学 | 7篇 |
矿业工程 | 6篇 |
能源动力 | 3篇 |
轻工业 | 113篇 |
水利工程 | 4篇 |
石油天然气 | 18篇 |
武器工业 | 9篇 |
无线电 | 73篇 |
一般工业技术 | 152篇 |
冶金工业 | 16篇 |
原子能技术 | 2篇 |
自动化技术 | 24篇 |
出版年
2024年 | 4篇 |
2023年 | 27篇 |
2022年 | 45篇 |
2021年 | 50篇 |
2020年 | 42篇 |
2019年 | 38篇 |
2018年 | 43篇 |
2017年 | 27篇 |
2016年 | 28篇 |
2015年 | 40篇 |
2014年 | 48篇 |
2013年 | 66篇 |
2012年 | 77篇 |
2011年 | 74篇 |
2010年 | 48篇 |
2009年 | 49篇 |
2008年 | 31篇 |
2007年 | 46篇 |
2006年 | 28篇 |
2005年 | 25篇 |
2004年 | 17篇 |
2003年 | 16篇 |
2002年 | 12篇 |
2001年 | 14篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1990年 | 1篇 |
1976年 | 1篇 |
1964年 | 1篇 |
1960年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有918条查询结果,搜索用时 31 毫秒
1.
分子印迹技术及其应用 总被引:3,自引:0,他引:3
分子印迹技术是将高分子科学、材料科学、生物学、化学工程等有机集成。基于分子印迹技术所制备的分子印迹聚合物具有选择性高、稳定性好、应用范围广等特点 ,近年来得到了日益广泛和深入的研究。介绍了分子印迹技术的原理、分子印迹聚合物的制备方法、分子印迹技术的应用场合和实例 ,并简要预测了分子印迹技术领域未来的发展趋势。 相似文献
2.
3.
Shaofeng Wang Jianwei Xu Yuejin Tong Lin Wang Chaobin He 《Polymer International》2005,54(9):1268-1274
A novel cholesterol‐imprinted polymer (CMIP‐H) was prepared by a hybrid method of covalent imprinting and non‐covalent imprinting. This approach involves the copolymerization of a template‐containing monomer, cholesteryl 2‐hydroxyethyl methacrylate carbonate, and a cross‐linker, followed by hydrolysis to afford a flexible guest‐binding site accompanied with the easy and efficient removal of a ‘sacrificial spacer’. The effect of solvent on the binding capacity of CMIP‐H towards cholesterol was studied, indicating that a good binding capacity towards cholesterol could be achieved in a less‐polar solvent. The binding experiments of CMIP‐H towards a series of structural analogues of cholesterol, including cholesterol acetate, progesterone and stigmasterol, were carried out in hexane. The results showed that CMIP‐H almost did not bind cholesterol acetate at all because the hydrogen‐bonding site is blocked. It exhibited a similar binding towards both cholesterol and stigmasterol, but much higher binding towards progesterone. Copyright © 2005 Society of Chemical Industry 相似文献
4.
Qingzhao Yao Yuming Zhou Yanqing Sun Xiaoyun Ye 《Journal of Inorganic and Organometallic Polymers and Materials》2008,18(4):477-484
TiO2 hybrid molecular imprinted polymer (MIP) for ethofumesate using methacrylic acid (MAA) as the functional monomer and silane
coupling agent 3-(trimethoxysilyl) propylmethacrylate (KH570) as organic–inorganic connective bridge was synthesized via photo-excitation
method. Hydrogen bond was proved to act between MAA and ethofumesate for pre- and post-polymerization binding properties as
testified by UV spectrometric method. KH570 modified TiO2 nanoparticles were prepared via sonochemical reaction, which can accelerate hydrolysis, increase collision chance for the
reactive system and improve the dispersion of the nanoparticles. Scanning electron microscope (SEM), transmission electron
microscope (TEM), binding and the adsorption kinetics experiments as well as thermogravimetric analysis (TGA) were employed
for characterization. The results indicated that the hybrid MIP revealed a larger surface area and more ordered imprinting
cavities with improved thermal stability compared to organic-only MIP. Furthermore, faster adsorption kinetics and enhancive
adsorption capacity were achieved, which made it promising in chemical sensor applications. 相似文献
5.
A molecularly imprinting polymer (MIP) was synthesized via bulk polymerization under different conditions using anti-ague drug cinchonine (CN) as template. Infrared spectra (IR) results show that the template CNand functional monomer α-methyl acrylic acid (MAA) formed complexes before polymerization and the structure of complexes was simulated by Hyperchem. The results indicate that there are hydrogen bond or ionic bond between functional monomer and template molecule in acetonitrile solution. The MIP made in cold-initiated photo-polymerization has higher separation performance than that in the therm-initiated polymerization. The separation of the isomers CN and cinchonidine (CD) can be successfully obtained when its separate factor α reaches 1.82. Scatchard analysis suggests that the MIP recognizing CN with two classes of binding sites. The partition coefficient Kd, 1 and apparent maximum number nmax, 1 of binding sites with high affinity are 131.43 μmol/L and 58. 90 μmol/g, respectively,while Kd, 2 and nmax, 2 of binding sites with low affinity are 2.32 mmol/L and 169.08 mmol/g, respectively. 相似文献
6.
Using nickel-2,2′-dipyridyl complex as a template, N-vinyl-2-pyrrolidone as the metal coordination functional monomer, and ethylene glycol dimethacrylate as the crosslinker, polyvinylidene fluoride (PVDF) hollow fiber ultrafiltration membrane as the supported membrane, metal complex imprinted polymeric membranes were prepared. The association constant of template-monomer interaction in the prepolymerization solution was estimated to be 4.38 × 104 (L/mol)2 by spectrophotometric titration analysis. The attenuated total reflection Fourier transform infrared spectroscopy and scanning electron micrograph characterization indicated that the surface of the support PVDF membrane was completely coated by the imprinted polymer layer after modification. The imprinted membranes exhibited the selective permeability for the template in certain nickel acetate solution. The molecularly imprinted membranes gave higher permeation separation factors at about pH 6, whereas increasing pressure would lower the separation ability. The effects of ion concentration, cations and counterions, ligand selectivity, pH, and trans-membrane pressure were investigated and the permeation performances of the imprinted membranes could be regarded as facilitated transport mechanism. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
7.
Chun‐Wei Liu Chi‐Hung Lee Shih‐Chieh Lin 《Journal of the Society for Information Display》2012,20(12):646-652
This study proposes a roll‐to‐roll process‐based sub‐wavelength grating, which is attached on a light bar to turn the side‐lit red/green/blue (620, 520, and 450 nm) incident rays into a uniformly and normally output white light with high illuminance from the light bar's surface. On the basis of the rigorous coupling wave analysis, the relationship between the first‐order transmission/reflection efficiency and the pitch of the gratings with different shapes was analyzed. The optimal design can effectively reduce the coupling length and enhance the white color balance for display applications. 相似文献
8.
利用简便的液相法,在室温下于不锈钢网上沉积ZnO纳米片和纳米花粗糙结构,接着通过浸渍法修饰低表面能物质硬脂酸,制备了超疏水不锈钢网。对沉积后的不锈钢网表面形貌、晶体结构、润湿性能、耐磨性能、油水分离性能等进行表征与测定。结果表明,该不锈钢网表面由纳米片和纳米花组成的微纳米结构ZnO构成,具有超疏水性,水接触角161 °;油水分离效率达98%,循环使用20次后分离效率仍保持在95.5%以上;具有良好的机械耐磨性,在高盐环境中表现出化学稳定性。 相似文献
9.
10.
硫酸铀酰印迹离子交换树脂的合成及识别特性研究 总被引:1,自引:0,他引:1
为进行稀溶液中铀的浓缩,以硫酸铀酰为模板、二乙基烯丙基胺为功能单体,在水中采用自组装分子印迹技术制备了硫酸铀酰印迹离子交换树脂.对树脂合成条件进行了优化,研究了pH值对吸附量的影响、分子印迹聚合物MIPs-4的等温吸附与吸附动力学、柱内吸附与淋洗曲线等树脂识别性能.结果表明:印迹树脂对硫酸铀酰的吸附性能比非印迹树脂好,可以在pH=1~6范围内应用,并在pH为2左右时吸附能力最强.MIPs-4树脂的吸附等温线为"优吸"型,吸附在约3h达到平衡.当C0=0.125mg·mL-1时,Kd=0.249L·g-1.吸附液ρ(U)=1.0 mg·mL-1、接触时间4min进行的柱内试验得出MIPs-4的穿透体积、穿透容量和饱和容量分别为柱内树脂的床体积(BV)的22倍、21.6 mg·mL-1和36.2 mg·mL-1.以0.05 mol·L-1 H2SO4 1.0 mol·L-1 NaCl为淋洗液时,淋洗体积仅4BV,流出液中最大铀浓度达到17.6 mg·mL-1.印迹树脂的吸附和解吸性能好,可应用于低浓度铀的浓缩及含铀废水的处理. 相似文献