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41.
TiO2/Mo-TiO2 的制备、表征和光催化活性 总被引:1,自引:0,他引:1
采用溶胶-凝胶法制备了掺 Mo 的 TiO2 粉末, 再由其制得 TiO2/Mo-TiO2 复合物光催化剂. 使用 X 射线光电子能谱、X 射线衍射、透射电镜、N2 吸附-脱附、紫外-可见漫反射光谱和荧光光谱等手段对催化剂进行了表征. 在紫外光照射下, 以甲基橙溶液降解为探针反应, 研究了 Mo 掺杂量对样品光催化活性的影响. 结果表明, Mo-TiO2 催化剂的活性不如纯 TiO2, 这是因为 Mo 离子促进了光生载流子的复合; 而带有 n-n 异质结半导体结构的 TiO2/Mo-TiO2 复合催化剂具有比纯 TiO2 和 Mo-TiO2 催化剂更高的光催化活性. 当 Mo 掺杂摩尔分数为 2%, TiO2:Mo-TiO2 质量比为 10:1 时, 活性是纯 TiO2 的 1.57 倍. 相似文献
42.
In this paper, strongly luminescent CdTe quantum dots (QDs) were synthesized in aqueous solution by a facile one-pot method.
The CdTe QDs were synthesized in a weakly acidic or neutral buffer solution composed of sodium borate (Na2B4O7) and sodium citrate (C6H5Na3O7). The pH of buffer solution and the ratio of the precursors were systematically optimized; the high-quality CdTe QDs with
progressively increasing fluorescence during 60 days storage were obtained. As-prepared QDs can be conjugated with a mouse
antibody alpha-fetoprotein via the reaction mediated by N-hydroxysuccinimide and 1-ethyl-3(3-dimethylaminopropyl) carbodiimide hydrochloride. The conjugate showed a red shift of 9
nm for the emission position. 相似文献
43.
Novel HPLC methods were developed for the analytical and semipreparative resolution of new antianginal drug ranolazine enantiomers. Good baseline enantioseparation was achieved using cellulose tris (3,5-dimethylphenylcarbamate) (CDMPC) chiral stationary phases (CSPs) under both normal-phase and polar organic modes. The validation of the analytical methods including linearity, LODs, recovery, and precision, and the semipreparative resolution of ranolazine racemate were carried out using methanol as mobile phase without any basic and acidic additives under polar organic mode, using CDMPC CSPs. At analytical scale, the elution times of both enantiomers were less than 7.5 min at 20 degrees C and 1.0 mL/min, with the separation factor (a) 1.88 and the resolution factor (R(s)) 2.95. At semipreparative scale, about 14.3 mg/h enantiomers could be isolated and elution times of both enantiomers were less than 13 min at 2.0 mL/min. To increase the throughput, the technique of overlapping injections was used. The first eluted enantiomer was isolated with a purity of 99.6% enantiomer excess (e.e.) and > 99.0% yield. The second enantiomer was isolated with a purity of 98.8% e.e. and > 99.0% yield. In addition, optical rotation and circular dichroism spectroscopy of both ranolazine enantiomers isolated were also investigated. 相似文献
44.
Aggregates of gold nanoparticles were formed by simple addition of a dithiafulvene derivative (DF) to an acetonitrile solution containing gold ions. The discrete gold nanoparticles in the aggregates were separated by monolayers of oxidized DF. No aggregation was observed with the addition of poly(vinylpyrrolidone) (PVP), which acted as a strong stabilizer and inhibited self‐assembly of the gold nanoparticles. DF acted as a reducing agent for gold ions, a stabilizer, and a tether for the resulting gold nanoparticles. Intermolecular S···S interaction and Au–S bonds might be the driving force for the self‐assembly of the gold nanoparticles. 相似文献
45.
46.
Wenbin Li Meifang Zhu Xingping Zhou Kensuke Naka Yoshiki Chujo 《Journal of Macromolecular Science: Physics》2013,52(4):549-555
The interparticle spacing of carboxyl functionalized gold nanoparticles (Au–COOH) was mediated by rigid cross‐linkers, octa(3‐aminopropyl)octasilsesquioxane (POSS–NH3 +) and poly(amidoamine) dendrimer terminated with hydroxyl groups (PAMAM–OH), and a flexible polymeric linker, poly(hexanyl viologen) (6‐VP). Regular interparticle spacing was achieved by utilizing POSS–NH3 + and PAMAM–OH dendrimer as cross‐linkers, whereas size growth of Au–COOH was observed featuring no interparticle spacing by utilizing 6‐VP as the cross‐linker. 相似文献
47.
48.
利用基于密度泛函理论的第一性原理平面波赝势方法结合准谐德拜模型研究NaCl结构的CaS在高压下的弹性和热力学性质.计算得到的零温零压下的晶格常数、体弹模量与实验值符合得很好.弹性常数和弹性模量随着压强的增大而增大.压强对体弹模量和热膨胀系数的影响大于温度的影响.热容随压强的升高而降低,在高温下热容接近于Dulong-Petit极限.通过求解Gibbs自由能计算得到B1结构和B2结构CaS的相变压为36.61 GPa. 相似文献
49.
采用4种含不同官能基团修饰剂改性的二氧化硅SiO2增强溶聚丁苯橡胶(SSBR)/顺丁橡胶(BR)共混体系, 制备了SSBR/BR/SiO2橡胶纳米复合材料, 研究了其结构与性能. 结果表明, 在混炼胶体系中, 与未改性SiO2填充的SSBR/BR相比, 改性SiO2填充的SSBR/BR门尼黏度及结合橡胶含量显著增大, 表明填料-橡胶相互作用显著提高; 硫化焦烧时间缩短60%, 硫化速度增大了35%~40%. 在硫化胶体系中改性SiO2填充的SSBR/BR具有更大的交联密度, 填料分散性明显改善, 同时也表现出更为优异的物理机械性能, 100%和300%定伸模量提高47%以上, 旋转滚筒式磨耗机法(DIN)磨耗降低5%~12%, 生热降低了约7%~13%, 热空气老化性能提升4%~22%, 代表滚动阻力的tanδ在60 ℃降低8%~13%. 此外, 与SSBR/BR/1165MP硫化胶相比, 用90 mmol/kg氨基改性SiO2填充的SSBR/BR硫化胶的抗湿滑性能提高6.9%, 表现出最优的综合性能. 填料的良好分散及填料与聚合物的相互作用增强对于提高SSBR/BR/SiO2胎面胶综合力学性能具有重要意义. 相似文献
50.
Cu-doped ZnO films with hexagonal wurtzite structure were deposited on silicon (1 1 1) substrates by radio frequency (RF) sputtering technique. An ultraviolet (UV) peak at ∼380 nm and a blue band centered at ∼430 nm were observed in the room temperature photoluminescent (PL) spectra. The UV emission peak was from the exciton transition. The blue emission band was assigned to the Zn interstitial (Zni) and Zn vacancy (VZn) level transition. A strong blue peak (∼435 nm) was observed in the PL spectra when the αCu (the area ratio of Cu-chips to the Zn target) was 1.5% at 100 W, and ZnO films had c-axis preferred orientation and smaller lattice mismatch. The influence of αCu and the sputtering power on the blue band was investigated. 相似文献