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131.
Photocatalytic Activity and Photo-Induced Wettability Conversion of TiO2 Thin Film Prepared by Sol-Gel Process on a Soda-Lime Glass 总被引:17,自引:0,他引:17
Watanabe Toshiya Fukayama Shigemichi Miyauchi Masahiro Fujishima Akira Hashimoto Kazuhito 《Journal of Sol-Gel Science and Technology》2000,19(1-3):71-76
We have developed the transparent photoactive TiO2 thin film coated on soda lime glass (SLG) by sol-gel process. Titanium dioxide thin films coated on SLG exhibit lower photocatalytic activity due to the thermal diffusion of Na ion from the SLG substrate. Thin SiO2 film precoating is very effective to prevent the thermal diffusion of Na ion. We have evaluated the photocatalytic decomposition of gaseous acetaldehyde and the photo-induced surface wettability of TiO2 films with and without SiO2 precoating layer. As expected, the TiO2 film on SiO2/SLG is more photoactive to decompose acetaldehyde than that on SLG. However, as for wettability conversion, there was little difference in the conversion rate between TiO2 film without SiO2, and TiO2 film with SiO2. Different dependence of Na ion diffusion on two kinds of photo-induced reaction on TiO2 is discussed based on the difference of the photo-induced reaction mechanism. 相似文献
132.
133.
含铁的柱撑膨润土光催化降解甲基橙 总被引:11,自引:0,他引:11
将两种含铁柱撑膨润土(Fe-Al-Bent和Fe-Bent)用作复相光催化剂, 表征结果证实它们具有很高的比表面积, 铁以高催化活性的α-Fe2O3存在于复相催化剂中. 以甲基橙为目标降解物, 考察了不同类型的催化剂、催化剂用量以及H2O2浓度对其降解的影响, 并与相应的均相Fenton反应进行了比较. 结果表明: 两种复相光催化剂的催化脱色性能和CODCr去除率都很高, 明显优于相应的均相Fenton反应, 且复合铁铝柱撑膨润土(Fe-Al-Bent)比单一的铁柱撑膨润土(Fe-Bent)催化性能更好, 此外它们还具有分离简单、重复使用性好等特点. 相似文献
134.
采用光催化法对造纸废水的处理进行了研究.探讨了光催化反应机理,比较了光催化剂的活性顺序,讨论了复相光催化剂的组成、用量、试液pH值、光照时间与COD、色度去除率的关系.实验结果表明:采用WO3/α-Fe2O3/W为复相光催化剂,其组成为WO3:α-Fe2O3:W=75:24:1,当其用量为0.500g、pH=6.5、光照22h,造纸废水的COD和色度去除率分别达到68.3%和71.2%. 相似文献
135.
特定结构光催化剂的制备及其构效关系 总被引:2,自引:0,他引:2
高效光催化剂的设计是光催化研究的关键.本文介绍了超临界处理、醇解、溶剂蒸发诱导自组装(EISA)法和喷雾干燥技术在特定结构TiO2和非钛催化剂制备中的应用,并初步介绍了光催化剂的构效关系,说明具有特定组成和形貌结构的光催化剂的制备对提高光催化性能起到了关键的作用. 相似文献
136.
A novel thermo-responsive 2,9(10),16(17),23(24)-tetrakis[(3-carboxyacrylamide) phthalocyaninato] zinc (ZnPc)-g-TiO2-g-poly(N-isopropylacrylamide) (PNIPAM) photocatalyst modified with phthalocyanines was prepared. The photocatalyst exhibited thermo-responsive properties due to the introduction of PNIPAM, which performed recovery for reuse above the lower critical solution temperature (LCST, about 26 °C). ZnPc-g-TiO2-g-PNIPAM effectively expanded the light response range to the visible light region and inhibited the recombination of electron–hole pairs, which enhanced the performance of the photocatalyst. As expected, ZnPc-g-TiO2-g-PNIPAM (0.3 g/L) exhibited excellent photocatalytic performance for the removal of Rhodamine B (RhB, 1.0 × 10−5 mol/L) and methylene blue (MB, 1.0 × 10−5 mol/L) under visible light, which reached 97.2% and 88.6% at 20 °C within 40 min, respectively. Furthermore, the influence of temperature upon photocatalytic performance was also investigated. When the temperature increased from 20 °C to 45 °C, the removal of RhB decreased by approximately 53.8%. The stability of the photocatalyst demonstrated that the photocatalytic activity was still above 80% for the removal of RhB after 3 cycles. Above all, this work provided an intelligent thermally responsive photocatalyst based on phthalocyanine for water purification under visible light. 相似文献
137.
Wenyu Fang Yiyu Feng Jian Gao Hui Wang Jing Ge Qingbin Yang Wei Feng 《Molecules (Basel, Switzerland)》2022,27(10)
Molecular photoswitches are considered to be important candidates in the field of solar energy storage due to their sensitive and reversible bidirectional optical response. Nevertheless, it is still a daunting challenge to design a molecular photoswitch to improve the low solar spectrum utilization and quantum yields while achieving charging and discharging of heat without solvent assistance. Herein, a series of visible-light-driven ethylene-bridged azobenzene (b-Azo) chromophores with different alkyne substituents which can undergo isomerization reactions promoted in both directions by visible light are reported. Their visible light responsiveness improves their solar spectrum utilization while also having high quantum yields. In addition, as the compounds are liquids, there is no need to dissolve the compounds in order to exploit this switching. The photoisomerization of b-Azo can be adjusted by alkyne-related substituents, and hexyne-substituted b-Azo is able to store and release photothermal energy with a high density of 106.1 J·g−1, and can achieve a temperature increase of 1.8 °C at a low temperature of −1 °C. 相似文献
138.
BixOyBrz光催化剂在有机药物废水处理领域有着非常广阔的潜在应用价值,但因光生电子和空穴的快速复合而表现出较低的光催化效率,进而限制了其应用范围。通过简易的水解-焙烧法原位制得一种新型的Bi3O4Br/Bi12O17Br2复合光催化剂,并以磺胺甲噁唑(SMX)为模拟药物污染物进行了光催化性能测试,对所制催化剂进行了X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)、紫外可见漫反射光谱(UV-Vis DRS)、电化学阻抗(EIS)、光致发光光谱(PL)等表征。结果表明所制备的Bi3O4Br/Bi12O17Br2复合光催化剂具有较强的光生载流子分离率、较低的界面电荷转移电阻,进而展示出优异的光催化降解SMX性能,在模拟太阳光下照射30 min,SMX降解率达到87%,相较于纯的Bi3O4Br和Bi12O17Br2催化剂,降解率分别提升了30%和24%。最后基于自由基捕获实验和催化剂能带结构分析了所制催化剂的降解机理。 相似文献
139.
通常采用以氢氧化物作为造孔剂,过渡金属硝酸盐或氯化物作为石墨化催化剂的传统两步法策略制备多孔石墨化碳材料。然而制备过程中多涉及有毒和腐蚀性试剂,且多步骤的过程耗时较长。本文以双氰胺为原料通过热缩聚反应得到g-C3N4,采用高铁酸钾为催化剂一步法实现g-C3N4的同步碳化-石墨化,并研究其光催化性能。与传统的两步法相比,该方法耗时少、效率高、无污染。与初始的g-C3N4材料相比,石墨化g-C3N4衍生碳质材料不仅显著改善了可见光的吸收,而且大大增强了光催化活性。研究了不同石墨化温度对g-C3N4衍生碳质材料在可见光下降解甲基橙溶液的影响。700 ℃下制备的衍生碳质材料的降解率为12.4 mg/g。光电化学测试结果表明,多孔g-C3N4衍生碳质材料的光生载流子密度、电荷分离和光电流(提高了5.4倍)均得到显著提高。因此,该简便、灵活方法为提高g-C3N4衍生碳质材料的吸附和光催化性能提供了一种有前景的、高效的途径。 相似文献
140.
Ya-Qi Zhang Lin Hou Hao-Xue Bi Xiao-Xue Fang Yuan-Yuan Ma Zhan-Gang Han 《化学:亚洲杂志》2021,16(12):1584-1591
Visible-light-driven photocatalytic Cr(VI) reduction is a promising pathway to moderate environmental pollution, in which the development of photocatalysts is pivotal. Herein, three hourglass-type phosphomolybdate-based hybrids with the formula of: (H2bpe)3[Zn(H2PO4)][Zn(bpe)(H2O)2]H{Zn[P4Mo6O31H6]2} ⋅ 6H2O ( 1 ) Na6[H2bz]2[ZnNa4(H2O)5]{Zn [P4Mo6O31H3]2} ⋅ 2H2O ( 2 ) and (H2mbpy) {[Zn(mbpy)(H2O)]2[Zn(H2O)]2}{Zn[P4Mo6O31H6]2} ⋅ 10H2O ( 3 ) (bpe=trans-1,2-bi(4-pyridyl)-ethylene; bz=4,4′-diaminobiphenyl; mbpy=4,4’-dimethyl-2,2’bipyridine) were synthesized under the guidance of the functional organic moiety modification strategy. Structural analysis showed that hybrids 1 – 3 have similar 2D layer-like spatial arrangements constructed by {Zn[P4Mo6]2} clusters and organic components with different conjugated degree. With excellent redox properties and wide visible-light absorption capacities, hybrids 1 – 3 display favourable photocatalytic activity for Cr(VI) reduction with 79%, 70% and 64% reduction rates, which are superior to that of only inorganic {Zn[P4Mo6]2} itself (21%). The investigation of organic components on photocatalytic performance of hybrids 1 – 3 suggested that the organic counter cations (bpe, bz and mbpy) can effectively affect the visible-light absorption, as well as the recombination of photogenerated carriers stemmed from {Zn[P4Mo6]2} clusters, further promoting their photocatalytic performances towards Cr(VI) reduction. This work provides an experimental basis for the design of functionalized photocatalysts via the modification of organic species. 相似文献