全文获取类型
收费全文 | 112篇 |
免费 | 22篇 |
国内免费 | 14篇 |
专业分类
化学 | 129篇 |
力学 | 1篇 |
物理学 | 18篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 11篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 7篇 |
2017年 | 5篇 |
2016年 | 9篇 |
2015年 | 7篇 |
2014年 | 11篇 |
2013年 | 8篇 |
2012年 | 3篇 |
2011年 | 8篇 |
2010年 | 3篇 |
2009年 | 6篇 |
2008年 | 1篇 |
2007年 | 7篇 |
2006年 | 3篇 |
2005年 | 6篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 8篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 1篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有148条查询结果,搜索用时 15 毫秒
61.
《Physics and Chemistry of Liquids》2012,50(2):231-242
Because of their wide ranging applications, the properties of chlorofluoro carbons (CFCs) and their alternatives are studied and correlated in terms of the parameters derived from molecular structures. The properties correlated are of physical, thermodynamic and transport in nature. The input parameters include molar refraction (R M), molecular connectivity (χ) and van der Waals equation coefficients (a and b), all of which are easily estimated from molecular structures. The correlations developed for the 11 properties studied showed average absolute deviations ranging between 3.5% and 13.7%. The correlation coefficients calculated for the equations developed ranged between 0.9557 and 0.9921. 相似文献
62.
Jerzy ChomaKatarzyna Jedynak Michal MarszewskiMietek Jaroniec 《Applied Surface Science》2012,258(8):3763-3770
Mesoporous carbon composites, containing nickel and nickel oxide nanoparticles, were obtained by soft-templating method. Samples were synthesized under acidic conditions using resorcinol and formaldehyde as carbon precursors, poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock co-polymer Lutrol F127 as a soft template and nickel and nickel oxide nanoparticles, and nickel nitrate as metal precursors. In addition, a one set of samples was obtained by impregnation of mesoporous carbons with a nickel nitrate solution followed by further annealing at 400 °C. Wide angle X-ray powder diffraction along with thermogravimetric analysis proved the presence of nickel nanoparticles in the final composites obtained using nickel and nickel oxide nanoparticles, and Ni(NO3)2 solution. Whereas, the impregnation of carbons with a nickel nitrate solution followed by annealing at 400 °C resulted in needle-like nickel oxide nanoparticles present inside the composites’ pores. Low-temperature (−196 °C) nitrogen physisorption, X-ray powder diffraction, and thermogravimetric analysis confirmed good adsorption and structural properties of the synthesized nickel-carbon composites, in particular, the samples possessed high surface areas (>600 m2/g), large total pore volumes (>0.50 cm3/g), and maxima of pore size distribution functions at circa 7 nm. It was found that the composites were partially graphitized during carbonization process at 850 °C. The samples are stable in an air environment below temperature of 500 °C. All these features make the synthesized nickel-carbon composites attractive materials for adsorption, catalysis, energy storage, and environmental applications. 相似文献
63.
Zhi-Peng Sun Xiao-Gang Zhang Hao Tong Rui-Li Xue Yan-Yu Liang Hu-Lin Li 《Applied Surface Science》2009,256(1):33-38
Pd nanoparticles highly dispersed onto the surface of ordered mesoporous carbons (OMCs) were synthesized successfully by poly(sodium-p-styrenesulfonate) (PSS) assisted microwave synthesis. Here, PSS served as a bifunctional molecule both for solubilizing and dispersing OMCs into aqueous solution and for jointing Pd2+ to facilitate the subsequent uniform formation of Pd nanoparticles on their surfaces. The effects of PSS on structural and electrochemical properties of Pd/OMCs were investigated. It was found that the addition of PSS facilitated Pd nanoparticles to disperse on the carbon surface. Electrochemical properties showed that Pd catalysts prepared with addition of PSS displayed better electrochemical activity and stability for formic acid electro-oxidation than those without PSS. 相似文献
64.
65.
用硬模板法合成了有序介孔碳(OMC),并以壳聚糖(Chitosan)作为分散剂制备了有序介孔碳-壳聚糖复合膜(OMC-Chitosan)修饰电极.应用该电极研究了尿酸(UA)的电化学行为以及实际样品的分析检测.在0.1 mol/L(pH 6.5)的磷酸盐(PBS)缓冲溶液中,UA在OMC-Chitosan修饰电极上于0.334 V处产生一灵敏的不可逆氧化峰,氧化峰电流(ipa)与UA的浓度在4.0×10-6~2.0×10-4 mol/L范围内呈良好的线性关系,相关系数为0.9997,检出限为2.0×10-6 mol/L.对0.2 mmol/L UA平行测定10次,相对标准偏差为3.8%,表明该电极重现性和稳定性良好. 相似文献
66.
通过简单的一步碳化方法, 以含氮的多孔有机骨架JUC-Z2为碳前驱物制备出氮掺杂多孔碳材料. 与原始JUC-Z2材料相比, 制备的多孔碳材料显示出明显提高的气体吸附量和增强的吸附焓. 其中JUC-Z2-900的CO2吸附量高达113 cm3·g-1, H2吸附量也达到246 cm3·g-1, 超过了大部分报道的多孔材料. 尤其是JUC-Z2-900的CH4吸附量在273 K, 1 bar下高达60 cm3·g-1, 据我们所知, 这一值为目前报道材料的最高值. 除此之外, 样品还显示出选择性吸附CO2的能力, 273 K下, JUC-Z2-900的CO2/N2的选择性高达10, CO2/H2的选择性也高达66. 另外, 样品具有很高的热稳定性, 有望应用在碳捕获和清洁能源储存等领域. 相似文献
67.
Application of Thermal Analysis to the Study of Some Waste Agricultural Products for the Preparation of Active Carbons 总被引:1,自引:0,他引:1
Lupascu T. Dranca I. Popa V. T. Vass M. 《Journal of Thermal Analysis and Calorimetry》2001,63(3):855-863
TG, DTG and DTA methods were used for the investigation of some waste agricultural products, such as grape seeds, walnut shells,
plum and peach stones, which can serve as raw materials for the production of active carbons. It was demonstrated that thermo
analytical methods are appropriate to study the thermal characteristics of the above wastes and the data obtained can be applied
to the technological processes of active carbon preparation.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
68.
The remarkable increase in the number of vehicles worldwide; and the lack of both technical and economical mechanisms of disposal make waste tires to be a serious source of pollution. One potential recycling process is pyrolysis followed by chemical activation process to produce porous activated carbons. 相似文献
69.
N. S. Polyakov G. A. Petukhova F. Stoeckli T. Centeno A. Lavanchy 《Russian Chemical Bulletin》1996,45(5):1071-1077
The influence of oxidation by nitric acid on the character of oxygen-containing functional surface groups and porous structure of active carbons is considered. Adsorption properties of the initial and oxidized carbons are studied using adsorption isotherms of vapor of n-hexane and polar substances (water and methanol).Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1132–1137, May, 1996. 相似文献
70.