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1.
将有机物2,5-二溴对苯二甲酸(H2L1)和2,2′-联吡啶(L2)作为双配体,使用溶剂热法和七水合硫酸锌(ZnSO4·7H2O)、六水合硝酸钴(Co(NO3)2·6H2O)分别反应,得到配合物[Zn(L1)(L2)(H2O)]n(1)和配合物[Co(L1)(L2)(H2O)]n(2)。采用单晶X射线衍射、元素分析、红外光谱、紫外光谱、荧光光谱、热重分析等测试方法对这两种物质进行分析研究。单晶测试结果表明配合物1是单斜晶系,以Zn2+配位连接L2-1与L2形成一维链状结构,各条链在分子间氢键和π…π共轭作用下有规律地堆叠形成三维网络结构。配合物2是三斜晶系,Co1离子和Co1i离子由H2L1上的羧酸氧原子O4和O4i连接,形成双齿螯合的配位结构单元,以Co2+配位连接 L2-1和L2形成二维网格结构,各层在O—H…O分子间氢键和范德瓦耳斯力作用下有规律的堆叠形成三维网络结构。配合物1和2均含有芳香杂环、羧基杂环和氮杂环,具有良好的荧光性质和热稳定性,最大发射波长分别为345 nm和333 nm。 相似文献
2.
聚硅氧烷涂敷的反相高效液相色谱固定相 总被引:5,自引:1,他引:5
用甲基乙烯基聚硅氧烷涂敷于硅烷化的微粒硅胶上,制备出一种新型的涂敷型反相高效液相色谱固定相。该固定相对极性、非极性和碱性化合物均有良好的分离能力,峰对称性好。对其恶性循环 了考察,连续使用三个月后,固定相的碳量和色谱性能仍保持不变。 相似文献
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通过化学镀和电化学镀的方法制备了一种Ni(OH)2电化学活性材料修饰三聚氰胺泡沫(MF)可压缩骨架的超级电容器电极材料MF/Ni(OH)2。MF/Ni(OH)2可压缩电极材料表现出最佳的电容性能,例如循环稳定性(即使在40 mA/cm-3的电流密度下经过2000次充放电循环后,可压缩电极仍能保持90.63%的初始电容)和可压缩稳定性(即使在压缩率为50%时,仍具有97.88%的电容保持率)。层状可压缩超级电容器由MF/Ni(OH)2弹性材料作为阳极,镍/碳(Ni/C)为阴极以及实验室中常用的滤纸作隔膜材料组成。这种超级电容器装置在不同的压缩下表现出良好的电化学性能和优异的压缩稳定性。最后,使用可压缩的超级电容器来点亮LED灯,以展示其在柔性电子设备中的应用。这些优化的电化学和机械性能表明MF/Ni(OH)2可作为可压缩超级电容器的应用中的候选电极。 相似文献
5.
Yuguo Li Ruiqin Peng Xianwu Xiu Xuelei Zheng Xiaosen Zhang Guannan Zhai 《Superlattices and Microstructures》2011,50(5):511-516
Tin oxide (SnO2) nanoparticles were fabricated by evaporation of Sn powers at 1000 °C in air pressure. The as-deposited SnO2 particles were single crystal structure, which were mostly spherical shape, the diameter of particles was ranging from 200 to 600 nm. The photoluminescence (PL) spectrum showed that a sharp emission peak at around 393 nm with the excitation wavelength at 325 nm, which suggested possible applications in nanoscaled optoelectronic devices. It was also found that the holding time affects the morphology of the products. The formation mechanism of SnO2 particles was discussed. 相似文献
6.
设p是适合p≡1(mod81的奇素数.本文主要利用初等方法证明了椭圆曲线y2=px(x2+1)在P≡9(rood16)时没有正整数点(x,y);并且对于p≡1(mod16)的情况,给出了该椭圆曲线有整数点的两个判别条件. 相似文献
7.
Chemical groups are known to tune the luminescent efficiencies of graphene-related nanomaterials, but some species, including the epoxide group (−COC−), are suspected to act as emission-quenching sites. Herein, by performing nonadiabatic excited-state dynamics simulations, we reveal a fast (within 300 fs) nonradiative excited-state decay of a graphene epoxide nanostructure from the lowest excited singlet (S1) state to the ground (S0) state via a conical intersection (CI), at which the energy difference between the S1 and S0 states is approximately zero. This CI is induced after breaking one C−O bond at the −COC− moiety during excited-state structural relaxation. This study ascertains the role of epoxide groups in inducing the nonradiative recombination of the excited electron-hole, providing important insights into the CI-promoted nonradiative de-excitations and the luminescence tuning of relevant materials. In addition, it shows the feasibility of utilizing nonadiabatic excited-state dynamics simulations to investigate the photophysical processes of the excited states of graphene nanomaterials. 相似文献
8.
Engineering the Band Gap States of the Rutile TiO2(110) Surface by Modulating the Active Heteroatom 下载免费PDF全文
Dr. Yaoguang Yu Xu Yang Dr. Yanling Zhao Xiangbin Zhang Dr. Liang An Miaoyan Huang Prof. Gang Chen Prof. Ruiqin Zhang 《Angewandte Chemie (International ed. in English)》2018,57(28):8550-8554
Introducing band gap states to TiO2 photocatalysts is an efficient strategy for expanding the range of accessible energy available in the solar spectrum. However, few approaches are able to introduce band gap states and improve photocatalytic performance simultaneously. Introducing band gap states by creating surface disorder can incapacitate reactivity where unambiguous adsorption sites are a prerequisite. An alternative method for introduction of band gap states is demonstrated in which selected heteroatoms are implanted at preferred surface sites. Theoretical prediction and experimental verification reveal that the implanted heteroatoms not only introduce band gap states without creating surface disorder, but also function as active sites for the CrVI reduction reaction. This promising approach may be applicable to the surfaces of other solar harvesting materials where engineered band gap states could be used to tune photophysical and ‐catalytic properties. 相似文献
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PM2.5 in an industrial district of Zhengzhou,China:Chemical composition and source apportionment 总被引:3,自引:0,他引:3
Zhengzhou is a developing city in China,that is heavily polluted by high levels of particulate matter.In this study.fine particulate matter(PM2.5) was collected and analyzed for their chemical composition(soluble ions,elements,elemental carbon(EC) and organic carbon(OC)) in an industrial district of Zhengzhou in 2010.The average concentrations of PM2.5 were 181,122,186 and 211μg/m3 for spring,summer, autumn and winter,respectively,with an annual average of 175μg/m3,far exceeding the PM2.5 regulation of USA National Air Quality Standards(15μg/m3).The dominant components of PM2.5 in Zhengzhou were secondary ions(sulphate and nitrate) and carbon fractions.Soluble ions,total carbon and elements contributed 41%,13%and 3%of PM2.5 mass,respectively.Soil dust,secondary aerosol and coal combustion, each contributing about 26%,24%and 23%of total PM2.5 mass,were the major sources of PM2.5,according to the result of positive matrix factorization analysis.A mixed source of biomass burning,oil combustion and incineration contributed 13%of PM2.5.Fine particulate matter arising from vehicles and industry contributed about 10%and 4%of PM2.5,respectively. 相似文献