全文获取类型
收费全文 | 75篇 |
免费 | 28篇 |
国内免费 | 25篇 |
专业分类
化学 | 76篇 |
晶体学 | 2篇 |
力学 | 1篇 |
数学 | 4篇 |
物理学 | 45篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 5篇 |
2015年 | 3篇 |
2014年 | 6篇 |
2013年 | 8篇 |
2012年 | 7篇 |
2011年 | 5篇 |
2010年 | 4篇 |
2009年 | 6篇 |
2008年 | 10篇 |
2007年 | 6篇 |
2006年 | 5篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 2篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有128条查询结果,搜索用时 31 毫秒
1.
2.
Chao-Yu Chen Yu-Ting Jhou Hui-Ling Lee Yu-Wen Lin 《Analytical and bioanalytical chemistry》2016,408(23):6295-6306
3.
用静电纺丝法制备了In(NO3)3/聚乙烯吡咯烷酮(PVP)纺丝前驱物, 然后分别在500、600、700℃时烧结得到三种In2O3 纳米纤维. 通过X 射线衍射(XRD)仪、热重差热分析(TG/DTA)、场发射扫描式电子显微镜(FE-SEM)表征结果得知, 500℃时In2O3的晶相已经形成, 且粒径为最小, 约为24 nm, 纳米纤维呈介孔结构.将三种烧结温度的In2O3纤维制作成气敏元件, 测试对比了三种元件对甲醛气体的敏感特性, 结果表明, 500℃烧结得到的In2O3纳米纤维在工作温度为240℃时响应最好, 对浓度为10×10-6 (体积分数, φ)甲醛的响应为7.用静电纺丝法合成了CdO 纳米颗粒, 通过XRD、SEM 表征得知CdO 呈粒径约为68 nm 的颗粒. 将In2O3和CdO以不同摩尔比(1:1, 10:1, 20:1)复合, 对比测试了纯In2O3及三种In2O3/CdO复合材料对应的气敏元件对甲醛的气敏特性, 测试结果表明当In2O3纳米纤维与CdO纳米颗粒以摩尔比10:1 复合时, 元件的工作温度较低(200℃), 且对甲醛表现出最佳的气敏特性, 对浓度为10×10-6甲醛的响应为13.6, 响应/恢复时间为140 s/32s. 最后对不同摩尔比复合的In2O3/CdO对甲醛的气敏机理进行了初步分析. 相似文献
4.
5.
Fang-Hua Zhao Zhong-Lin Li Shu-Fang Zhang Jian-Hui Han Mei Zhang Jun Han Yu-Wen Lin Jin-Mao You 《Acta Crystallographica. Section C, Structural Chemistry》2020,76(2):148-158
Two new metal–organic frameworks (MOFs), namely, three‐dimensional poly[diaquabis{μ2‐1,4‐bis[(2‐methyl‐1H‐imidazol‐1‐yl)methyl]benzene}bis(μ2‐glutarato)dinickel(II)] monohydrate], {[Ni2(C5H6O4)2(C16H18N4)2(H2O)2]·H2O}n or {[Ni2(Glu)2(1,4‐mbix)2(H2O)2]·H2O}n, ( I ), and two‐dimensional poly[[{μ2‐1,4‐bis[(2‐methyl‐1H‐imidazol‐1‐yl)methyl]benzene}(μ2‐glutarato)zinc(II)] tetrahydrate], {[Zn(C5H6O4)(C16H18N4)]·4H2O}n or {[Zn(Glu)(1,4‐mbix)]·4H2O}n ( II ), have been synthesized hydrothermally using glutarate (Glu2?) mixed with 1,4‐bis[(2‐methyl‐1H‐imidazol‐1‐yl)methyl]benzene (1,4‐mbix), and characterized by single‐crystal X‐ray diffraction, IR and UV–Vis spectroscopy, powder X‐ray diffraction, and thermogravimetric and photoluminescence analyses. NiII MOF ( I ) shows a 4‐connected 3D framework with point symbol 66, but is not a typical dia network. ZnII MOF ( II ) displays a two‐dimensional 44‐ sql network with one‐dimensional water chains penetrating the grids along the c direction. The solid‐state photoluminescence analysis of ( II ) was performed at room temperature and the MOF exhibits highly selective sensing toward Fe3+ and Cr2O72? ions in aqueous solution. 相似文献
6.
Yu-Wen Cheng Hua-Long Su Wen-Han Lin Ching-Fuh Lin 《Journal of Sol-Gel Science and Technology》2014,70(1):81-89
Sol–gel zinc oxide (ZnO) thin films generally have non-uniform stripes. After annealing at high temperatures, these thin films are rough and granular. When ZnO rods are grown on such rough and non-uniform surface with the hydrothermal method, collimation, crystalline structure, and defect density are very poor. Here we explore a method to solve this problem. The ZnO thin film is first coated with an Au layer to prohibit the vertical extension of crystallization during the annealing period. As a result, the surface morphology of ZnO thin film is very flat and uniform after annealing. Afterwards, the ZnO rods are grown on the flat and uniform thin film, which gives rise to ZnO rods with very good collimation and crystalline structure. The extremely flat ZnO thin film even enables the fabrication of patterned ZnO rod arrays with regular shapes through lithography. 相似文献
7.
Ren-Min Wu Na Qi Yu-Wen Jia Zhu Guan Liang-Ren Zhang Li-He Zhang Zhen-Jun Yang 《中国化学快报》2014,25(12):1583-1585
A facile and efficient protocol for the synthesis of sulfur substituted-cyclopyrophosphate of cIDPRE(P_S~1-cIDPRE) was developed.The key step was the cyclization process which was completed by the sulfur substituted cyclization precursor 1b via the one-pot phosphoramidite strategy. 相似文献
8.
L-Shell X-Ray Yields and Production Cross Sections of Zr and Mo Bombarded by Slow Highly Charged Ar16+ Ions 下载免费PDF全文
The L-shell x-ray yields of Zr and Mo bombarded by slow Ar16+ ions are measured. The energy of the Ar^16+ ions ranges from about 150 keV to 350 keV. The L-shell x-ray production cross sections of Zr and Mo are extracted from these yields data. The explanation of these experimental results is in the framework of the adiabatic direct- ionization and the binding energy modified BEA approximation. We consider, in the slow asymmetric collisions such as Ar and Mo/Zr, the transient united atoms (UA) are formed during the ion-surface interaction and the direct-ionization is the main mechanism for the inner-shell vacancy production. Generally, the theoretical results are in good agreement with the experimental data. 相似文献
9.
A series of Ni–B catalysts were prepared by mixing nickel acetate in 50% ethanol/water or methanol/water solution. The solution of sodium borohydride (1 M) in excess amount to nickel was then added dropwise into the mixture to ensure full reduction of nickel cations. The mol ratio of boron to nickel in mother solution was 3 to 1. The effects of preparation conditions such as temperature, stirring speed, and sheltering gas on the particle size, surface compositions, electronic states of surface atoms and catalytic activities of the Ni–B catalysts were studied. Ranel nickel catalyst was included for comparison. These catalysts were characterized by N2 sorption, X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. The catalysts were tested for liquid phase hydrogenation of p-chloronitrobenzene. All of the catalysts prepared in this study had nanosized particles. The preparation condition has significant influence on the particle size and surface compositions of the catalyst. The Ni–B catalyst was passivated by boron; therefore it was more stable than Raney nickel and did not catch fire after exposure to air. The catalysts prepared under N2 flow could suppress the oxidation of Ni by the dissolved oxygen in water and had metallic state of nickel. The catalyst prepared with vigorous stirring at 25°C under N2 stream yielded the smallest particles and resulted in the highest activity. It was much more active than the Raney nickel catalyst. The reaction condition also has pronounced effect on the hydrogenation activity. Using methanol as the reaction solvent increased p-chloronitrobenzene conversion to a large extent, compared to that using ethanol as the reaction medium. The selectivity of main product (p-chloroaniline) was greater than 99% on all of the Ni–B catalysts. 相似文献
10.
A series of alumina-supported alkaline earth metal oxide catalysts were prepared by incipient-wetness impregnation. These
catalysts were characterized by nitrogen-sorption to determine their surface areas and pore size distributions. The basicities
of these catalysts were characterized by temperature-programmed desorption of carbon dioxide. The TPD results demonstrate
that all of the catalysts have one-peak profiles. The basicity increases with increasing atomic number of the alkaline earth
metal. The alumina-supported alkaline earth oxides exhibit the same basic properties as bulk metal oxides. However, the presence
of alumina can increase the mechanical strength of the catalyst, since the alkaline earth oxides have a weak mechanical strength.
The basic properties of the catalysts are strongly influenced by the calcination temperature. 相似文献