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141.
通过酚类与六甲基环三硅氧烷(D3)的调聚反应,首先合成了一类含芳氧端基的聚二甲基硅氧烷(AOS).采用UV、IR、1HNMR、元素分析、分子量测定等方法,确证了所合成聚合物的结构.讨论了反应试剂摩尔比和反应条件对调聚产物分子量的影响;研究了AOS的结构与杀菌功能、絮凝作用以及水解速度的关系.  相似文献   
142.
In the first part of this review, the authors give a survey on the literature of vibrational spectroscopy of phenol, phenol derivatives, and other phenolic componds from the last decade of the last century through today. The classical and modern methods of vibrational spectroscopy are also introduced and a glossary is included to aid comprehension. The second part deals with the literature regarding the importance of vibrational spectroscopy in the investigation and identification of phenolic compounds in natural substances, the application of vibrational spectroscopy in composite and synthetic polymer chemistry, and following of chemical processes and investigating their resulting products. Vibrational spectroscopy is a very good tool for determination of molecular structures and is important in chemical analysis and in the chemical industry.  相似文献   
143.
以NH4F为掺杂前体,采用简单的一步醇-水热法制备了F掺杂BiVO4光催化剂。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、紫外-可见漫反射光谱(UV-Vis)和光致发光光谱(PL)表征了这些光催化剂的物理化学性质。在少量H2O2存在条件下,以可见光照射下光催化降解苯酚的反应测定了这些光催化剂的催化活性。研究表明,相较于未掺杂的BiVO4样品而言,F掺杂BiVO4样品不仅仍保留了单斜结构,而且有更高的结晶度、表面氧空位密度和光生电荷载流子分离效率,更强的光吸收和更低的带隙能。在这些F掺杂BiVO4样品中,以nF/nBi的理论值为1.0且带隙能为2.43 eV的F掺杂BiVO4样品的光催化活性最好(90 min内苯酚的降解率可达95%)。这一优良的光催化性能与其具有最高的结晶度、表面氧空位密度和光生电荷载流子分离效率,最强的光吸收和最低的带隙能有关。  相似文献   
144.
有 pyronine 酚骨骼的二基于 rosamine 的 pH 探针 1a 和 1b 被简单一步舞反应设计并且综合。pH 滴定实验向氢离子在 550-750 nm 附近在在离开上荧光回答附近显示出那探针 1a 和 1b 展览。pK 探查 1a 的 是 8.29,当因为氢,探查 1b 的增加到 12.1 时,在它内结合。选择、竞争的实验显示普通离子和氨基酸没介入他们有氢离子的排放。而且,共焦荧光灯成像证明探查 1a 能在 HeLa 和 Ges-1 房间作为线粒体 biomarker 被服务。  相似文献   
145.
We describe a selective aerobic oxidation of meta‐biaryl phenols that enables rapid access to functionalized phenanthrenes. Aerobic oxidations attract interest due to their efficiency, but remain underutilized in complex molecule settings due to challenges of selectivity. We discuss these issues in the context of Cu catalysis, and highlight the advantages of confining oxygen activation and substrate oxidation to the catalyst's inner‐coordination sphere. This gives rise to predictable selectivity that we use for a concise synthesis of the aporphine dehydronornuciferine.  相似文献   
146.
The molecular structures of N(o-C6H4OH)3, PhN(o-C6H4OH)2, andp-TolN(o-C6H4OMe)2 have been determined by X-ray diffraction, thereby indicating several structural differences. For example, whereas the nitrogen in N(o-C6H4OH)3 is pyramidal with ΣC–N–C = 348.3, the nitrogen atoms in PhN(o-C6H4OH)2 andp-TolN(o-C6H4OMe)2 are trigonal planar with ΣC–N–C = 359.9 and ΣC–N–C = 360.0, respectively. The phenyl andp-tolyl groups of PhN(o-C6H4OH)2 andp-TolN(o-C6H4OMe)2 lie close to the trigonal plane, while theo-C6H4OH ando-C6H4OMe groups are almost orthogonal to this plane. The coplanar and orthogonal orientations of the aryl groups of PhN(o-C6H4OH)2 andp-TolN(o-C6H4OMe)2 are in marked contrast to those of the phenyl groups within Ph3N, which exhibit dihedral angles in the range 38–52 and approximateD3 symmetry. The observed structures of PhN(o-C6H4OH)2 andp-TolN(o-C6H4OMe)2 may be rationalized in terms of maximizing delocalization of the nitrogen lone pair into the phenyl andp-tolyl groups, while minimizing unfavorable overlap with theo-C6H4OH ando-C6H4OMe groups due to the presence of π-donatingortho-substituents; the orthogonal orientation of theo-C6H4OH ando-C6H4OMe groups is also one that minimizes unfavorable steric interactions between theortho-substituents.  相似文献   
147.
148.
The electrochemical response of phenol at acetylene black (AB)-dihexadecyl hydrogen phosphate (DHP) composite modified glassy carbon electrode in the presence of cetyltrimethylammonium bromide (CTAB) was investigated. In this system, a sensitive oxidation peak at 0.62 V (SCE) was obtained. The electrode process and the influence of CTAB on the oxidation of phenol were explored by chronocoulometry and linear sweep voltammetry (LSV). Experimental conditions for the determination of phenol were optimized. In the range of 5.0 × 10−7 to 1.2 × 10−5 M, the phenol concentration was linear with the oxidation peak current and the detection limit was found to be 1.0 × 10−7 M for 3 min accumulation. The method was applied for the determination of phenol in lake water and the results were satisfactory. Published in Russian in Elektrokhimiya, 2008, Vol. 44, No. 2, pp. 222–229. The text was submitted by the authors in English.  相似文献   
149.
The metal complexes of N, N′‐bis (o‐hydroxy acetophenone) propylene diamine (HPPn) Schiff base were supported on cross‐linked polystyrene beads. The complexation of iron(III), copper(II), and zinc(II) ions on polymer‐anchored HPPn Schiff base was 83.4, 85.7, and 84.5 wt%, respectively, whereas the complexation of these metal ions on unsupported HPPn Schiff base was 82.3, 84.5, and 83.9 wt%. The iron(III) complexes of HPPn Schiff base were octahedral in geometry, whereas copper(II) and zinc(II) ions complexes were square planar and tetrahedral. Complexation of metal ions increased the thermal stability of HPPn Schiff base. Catalytic activity of metal complexes was tested by studying the oxidation of phenol and epoxidation of cyclohexene in the presence of hydrogen peroxide. The polymer‐supported HPPn Schiff base complexes of iron(III) ions showed 73.0 wt% conversion of phenol and 90.6 wt% conversion of cyclohexene at a molar ratio of 1:1:1 of substrate to catalyst and hydrogen peroxide, but unsupported complexes of iron(III) ions showed 63.8 wt% conversion for phenol and 83.2 wt% conversion for cyclohexene. The product selectivity for catechol (CTL) and epoxy cyclohexane (ECH) was 93.1 and 98.3 wt%, respectively with supported HPPn Schiff base complexes of iron(III) ions but was lower with HPPn Schiff base complexes of copper(II) and zinc(II) ions. Activation energy for the epoxidation of cyclohexene and phenol conversion with unsupported HPPn Schiff base complexes of iron(III) ions was 16.6 kJ mol?1 and 21.2 kJ mol?1, respectively, but was lower with supported complexes of iron(III) ions. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
150.
The protonation of the electrochemically generated (0.1 M solution of tetrabutylammonium perchlorate in DMF) 1,3-dinitrobenzene (1) dianions with phenol, ethanol, tert-butanol, and 1-butyl-3-methylimidazolium cation was studied by cyclic voltammetry and chronoamperometry at the carbositall working electrode. The rate constants for the protonation (k) of the dianion of compound 1 by phenol, 1-butyl-3-methylimidazolium cation, ethanol, and tert-butanol were estimated by the comparison of the data of cyclic voltammetry and chronoamperometry with the digital simulation results, being 100, 50, 1.5, and 0.01 L mol−1 s−1, respectively. The similarly obtained k value for the protonation of the dianion of 1,4-dinitrobenzene (2) with phenol is 13 L mol−1 s−1. According to the quantum chemical calculation results, the protonation of the dianions of compounds 1 and 2 with phenol and 1-butyl-3-methylimidazolium cation can be classified as orbital-controlled reactions. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1463–1466, July, 2008.  相似文献   
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