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141.
Photocatalyst Materials for Water Splitting 总被引:4,自引:0,他引:4
Akihiko Kudo 《Catalysis Surveys from Asia》2003,7(1):31-38
Various photocatalyst materials developed by the group of the present author are described. Alkali and alkaline earth tantalates have arisen as a new group of photocatalyst materials for splitting of water into H2 and O2 under ultraviolet irradiation. They showed activities even without co-catalysts such as Pt, being different from titanate photocatalysts. When NiO co-catalysts were loaded on the tantalate photocatalysts, the photocatalytic activities were markedly increased. Among the tantalates, NiO/NaTaO3 doped with La showed the highest activity. BiVO4, AgNO3, and TiO2 co-doped with Cr and Sb photocatalysts showed high activities for O2 evolution in the presence of a sacrificial reagent (Ag+) under visible light irradiation ( > 420 nm). Pt/SrTiO3 co-doped with Cr and Sb or Ta, Pt/NaInS2, and Pt/AgInZn7S9 photocatalysts showed high activities for H2 evolution from aqueous solutions containing reducing reagents under visible light irradiation. Furthermore, Cu- or Ni-doped ZnS photocatalysts showed H2 evolution activities even without co-catalysts such as Pt. 相似文献
142.
Yasumichi Matsumoto Noriyuki Tanaka Hideki Kato 《Journal of solid state chemistry》2004,177(11):4205-4212
Photoelectrochemical measurements of TiO2, NaTaO3, and Cr or Sb doped TiO2 and SrTiO3 photocatalysts were carried out in H2 and O2 saturated electrolytes in order to evaluate the reverse reactions during water photolysis. The poor activity of TiO2 as a result of reverse photoreactions of O2 reduction and H2 oxidation was revealed with the respective high cathodic and anodic photocurrents. The rise in the photocurrents at NaTaO3 after La doping was in harmony with the doping-induced increase in the photocatalytic activity. NiO loading suppresses the O2 photoreverse reactions, which declines photocatalytic activity, and/or promotes the photo-oxidation of water, because the O2 photo-reduction current was scarcely observed near the flatband potential. Photocurrents of O2 reduction and H2 oxidation were observed under visible light for the Cr and Sb doped SrTiO3 and TiO2, respectively. These phenomena are in harmony with the previous reports on the photocatalysts examined with sacrificial reagents. 相似文献
143.
磁载WO3-TiO2/SiO2/Fe3O4复合光催化剂的制备及其光催化活性 总被引:9,自引:0,他引:9
用溶胶-凝胶法在表面包覆了SiO2的磁基体Fe3O4上负载TiO2,从而得到了易于磁性固液分离的磁载WO3-TiO2/SiO2/Fe3O4复合光催化剂,并通过IR,XRD,SEM和XPS等测试手段对催化剂进行了表征.研究了磁载WO3-TiO2/SiO2/Fe3O4复合光催化剂对亚甲基蓝溶液脱色的性能,并考察了WO3掺杂量对样品催化活性的影响.结果表明,n(WO3)/n(TiO2)=0.001时,磁载WO3-TiO2/SiO2/Fe3O4复合光催化剂的催化活性最高,循环使用3次时脱色率仍保持在98%. 相似文献
144.
Pt/CdS光催化剂表面修饰和表面结构 总被引:1,自引:0,他引:1
Pt/CdS光催化剂表面修饰和表面结构张虎勤陈开勋*金振声(西北大学化工系西安710069)(中国科学院兰州化学物理研究所兰州)关键词光催化剂,半导体,表面组成,表面修饰1996-05-20收稿,1996-09-28修回近年来对在Pt/CdS催化剂上... 相似文献
145.
Guoqiang Li Tetsuya Kako Zhigang Zou Jinhua Ye 《Journal of solid state chemistry》2007,180(10):2845-2850
A series of orthorhombic photocatalysts (AgNbO3)1−x(NaNbO3)x solid solutions have been synthesized by a solid-state reaction method. The composition dependence of the photophysical and photocatalytic properties of synthesized solid solutions has been investigated systematically. With an increase in the content of NaNbO3, we found that (1) the lattice parameters decreased; (2) the Nb-O bond length in NbO6 octahedron reduced; (3) the band gap increased; and (4) the mean particle size decreased while the Brunauer-Emmett-Teller (BET) surface area increased. Photocatalytic activities of the (AgNbO3)1−x(NaNbO3)x (0?x?0.5) samples were evaluated from gaseous 2-propanol (IPA) decomposition into acetone and CO2 under visible-light irradiation emitted from blue-light-emitting diodes (BLEDs; light intensity: 0.01 mW cm−2). Among all the samples, the (AgNbO3)0.6(NaNbO3)0.4 sample showed the highest photocatalytic activity. 相似文献
146.
Riyadh Zendin Mawlud Sangar S. Ahmed Sobhan Mortazavi-Derazkola Omid Amiri Zahra Salehi Peshawa H. Mahmood 《应用有机金属化学》2020,34(8):e5652
In this study, dendrite-like Sn nanocomposites were achieved by engineering the synthesis parameters. The dendritic Sn nanostructures show higher photocatalytic activity compared to nanoplate Sn and hierarchical Sn nanostructures. Flower-like Sn–Cu and cactus-like Sn–Ag nanostructures were prepared to improve the photocatalytic activity of Sn nanostructures. Adding Cu and Ag improved the photocatalytic activity of Sn by 24% and 46%, respectively. The photodegradation results revealed that the cactus-like Sn–Ag has a high degradation rate (5.3 × 10−4 mmol L−1 min−1) compared to the Sn nanostructures (2.9 × 10−4 mmol L−1 min−1). This work provides new insight into the design of highly efficient photocatalysts by engineering the morphology. 相似文献
147.
In this work, the photocatalytic activity of the synthesized graphene oxide (GO)‐Fe3O4/TiO2 mesoporous photocatalysts was evaluated using chlorpyrifos (CP) as a contaminant. The nano‐photocatalyst was characterized by X‐ray diffraction, field emission scanning electron microscopy with energy‐dispersive X‐ray spectroscopy, transmission electron microscopy, and specific surface area by the Brunauer–Emmett–Teller method. Using visible light, the GO‐Fe3O4/TiO2 mesoporous photocatalyst was investigated on the degradation of CP pesticide. The GO‐Fe3O4/TiO2 photocatalyst displayed a good photocatalytic activity, which was achieving 97% of CP degradation after 60 min. Finally, experiments were performed to evaluate GO‐Fe3O4/TiO2 mesoporous nanocatalyst activity on repeated applications; after several uses, its photocatalytic activity was retained, which indicated stability. 相似文献
148.
Three-dimensional (3D) hierarchical porous TiO2/InVO4 nanocomposites were fabricated by loading TiO2 nanoparticles on the surface of porous InVO4 microspheres. X-ray diffractometer (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis spectroscopy and photoluminescence spectroscopy (PL) were adopted to analyze the structure–property relationship of samples. The results show that the surface of as-prepared TiO2/InVO4 nanocomposites are composed of uniformly interconnected bi-phase nanocrystals, forming a close interface between these two components, which is favorable for the highly efficient interparticle electron transfer to achieve enhanced photocatalytic properties. However, the adsorption ability is decreased due to the loading of TiO2 nanoparticles on the surface of InVO4. Therefore, under the joint action of these factors, the TiO2/InVO4 nanocomposites achieve the best photocatalytic activity when the mole ratio of In:Ti reaches 4:1, and the visible-light photocatalytic activity is about as 3.3 times high as that of pure InVO4 without modification. 相似文献
149.
Titania deposited on soft magnetic activated carbon as a magnetically separable photocatalyst with enhanced activity 总被引:1,自引:0,他引:1
Magnetically separable composite photocatalysts, TiO2 deposited on soft magnetic ferrite activated carbon (TFAC), were prepared by sol-gel and dip-coating technique. The prepared composites were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectra (FTIR), optical absorption spectroscopy, vibrating sample magnetometer (VSM) and nitrogen adsorption. These photocatalysts exhibited enhanced photocatalytic activity compared to Degussa P25 for the degradation of methyl orange (MO) in aqueous solution. The kinetics of MO degradation was well fitted to the Langmuir-Hinshelwood model. The samples showed good magnetic response and could be completely recovered by an external magnet. Furthermore, the photocatalysts could maintain high photocatalytic activity after five cycles, and the degradation rate of MO was still close to 90%. 相似文献
150.
以活性炭为载体,通过溶胶-凝胶法分别制备了Fe、Ag、Zn、Mn和Cr过渡金属离子掺杂TiO2/活性炭(X-TiO2/AC,X-TA;X:过渡金属离子)复合体,利用X射线衍射(XRD)、比表面积(BET)、X光电子能谱(XPS)、扫描电镜(SEM)、电子自旋共振谱(ESR)和荧光光谱(FS)对其结构进行表征.以罗丹明B的光催化降解为探针实验,评价掺杂负载型复合体的双协同光催化性能和使用寿命,提出双协同光催化扩增机制,并探讨了掺杂率和负载率对双协同扩增效果影响.结果表明:通过活性炭吸附和离子掺杂对TiO2光催化性能表现出双协同扩增作用,导致X-TA对罗丹明B的降解速率常数kapp大于掺杂X-TiO2粉体和TA负载体之和.同时,掺杂率和负载率共同影响协同效应,当Fe离子掺杂率和Fe-TiO2负载率分别为0.3%和10%时,Fe-TA复合体kapp最大为0.0208min-1.另外,过渡金属离子掺杂对TiO2光催化性能提高程度按掺杂离子Ag、Zn、Mn、Cr、Fe递增.掺杂后金属离子的价态、得电子能力、比表面积和掺杂TiO2颗粒尺寸上的差异决定了不同离子掺杂负载型复合体催化性能不同,复合体寿命降低的主要原因是由于活性组分从载体上流失所引起. 相似文献