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排序方式: 共有380条查询结果,搜索用时 31 毫秒
11.
Wen Zhou Xiao-Li Sun Lin Gu Fei-Fei Bao Xin-Xin Xu Chun-Yan Pang Zhi-Guo Gu Zaijun Li 《Journal of Radioanalytical and Nuclear Chemistry》2014,300(2):843-852
Three new mesoporous silica materials IL15SGs (HF15SG, TF15SG and DF15SG) doped with benzo-15-crown-5 and imidazolium based ionic liquids (C8mim+PF6 ?, C8mim+BF4 ? or C8mim+NTf 2 ? ) have been prepared by a simple approach to separating lithium isotopes. The formed mesoporous structures of silica gels have been confirmed by transmission electron microscopy image and N2 gas adsorption–desorption isotherm. Imidazolium ionic liquids acted as templates to prepare mesoporous materials, additives to stabilize extractant within silica gel, and synergetic agents to separate the lithium isotopes. Factors such as lithium salt concentration, initial pH, counter anion of lithium salt, extraction time, and temperature on the lithium isotopes separation were examined. Under optimized conditions, the extraction efficiency of HF15SG, TF15SG and DF15SG were found to be 11.43, 10.59 and 13.07 %, respectively. The heavier isotope 7Li was concentrated in the solution phase while the lighter isotope 6Li was enriched in the gel phase. The solid–liquid extraction maximum single-stage isotopes separation factor of 6Li–7Li in the solid–liquid extraction was up to 1.046 ± 0.002. X-ray crystal structure analysis indicated that the lithium salt was extracted into the solid phase with crown ether forming [(Li0.5)2(B15)2(H2O)]+ complexes. IL15SGs were also easily regenerated by stripping with 20 mmol L?1 HCl and reused in the consecutive removal of lithium ion in five cycles. 相似文献
12.
合成了2个相似的多吡啶类双核镍配合物[Ni_2(L)_2Cl_2](ClO_4)_2·3H_2O (1)和[Ni_2(L)_2Cl_2](PF_6)_2 (2)(L=N,N-bis(pyridin-2-ylmethyl)-4-(4-((pyridin-2-ylmethyl)amino)benzyl)aniline),通过X射线单晶衍射对其结构进行测定并解析,并利用元素分析、红外光谱对其进行表征。另外,通过噻唑蓝(MTT)比色法检验了 2个配合物对HeLa细胞、BGC-823细胞、NCI-H460细胞以及HepG-2细胞的体外毒性作用,结果表明2个配合物均对NCI-H460细胞表现出良好的毒性作用,IC_(50)值分别为(26.0±2.2)μmol·L~(-1)(1)和(31.3±2.7) μmol·L-~1 (2)。进一步通过Hoechst 33342染色、活性氧水平检测、线粒体膜电位的测定和分析探究了配合物1的抗肿瘤作用机制,结果表明,该配合物可能通过线粒体途径来诱导细胞凋亡从而对癌细胞产生致死作用。 相似文献
13.
以3,5-二硝基苯甲酸(3,5-Hdnbc)和2,2′-联吡啶(2,2′-bipy)为配体,与Zn2+和Cu2+反应,得到了4个配合物[Zn(3,5-dnbc)2(2,2′-bipy)(H2O)]·(3,5-Hdnbc)(1),[Cu(3,5-dnbc)2(2,2′-bipy)(H2O)](2),[Cu(2,2′-bipy)2(3,5-dnbc)](NO3)·2(3,5-Hdnbc)(3),和[Cu(2,2′-bipy)2Cl](3,5-dnbc)·(3,5-Hdnbc)(4)。用元素分析、红外光谱对其进行了表征,并用单晶X-射线衍射测定了配合物的晶体结构;对配合物1和2进行了热重分析。4个配合物均为单核分子。配合物1中,Zn2+离子是五配位的三角双锥结构;配合物2中,Cu2+离子是五配位的变形四方锥结构;配合物3和4中,Cu2+离子均是五配位的三角双锥结构;配合物中存在氢键和π-π堆积等弱的分子间作用力。 相似文献
14.
以3-硝基邻苯二甲酸和咪唑及2,2′-联吡啶为配体构筑了2种配合物[Zn2(npa)2(Im)4](1)和[Cd2(npa)2(2,2′-bipy)2(H2O)2]·2H2O(2)(npa2-=3-硝基邻苯二甲酸根,Im=咪唑,2,2′-bipy=2,2′-联吡啶)。用元素分析、红外光谱对其进行了表征,并用单晶X-射线衍射测定了配合物的晶体结构;测定了配合物1和2的热稳定性。2个配合物均为双核分子,具有M2C8O4十四元大环结构。配合物1的双核单元通过分子间氢键形成3D网络结构,配合物2的双核单元通过分子间氢键和π-π堆积形成2D层状结构。 相似文献
15.
Zhen Zhang Ying-Lin Gu Zheng-Yang Wang Huan-Nan Wang Yan Zhao Xue-Mei Chu Chun-Yan Zhang Mao-Cai Yan 《Journal of heterocyclic chemistry》2020,57(3):1165-1172
Novel indole amide derivatives C1-C10 were successfully synthesized and characterized by 1H NMR, 13C NMR, IR, MS, and elemental analysis, and their molecular formulas were C14H10N6O, C13H10N4O, C16H13N3O2, C19H14N2O2, C16H11N3OS, C15H13N3O, C12H9N5O, C16H10ClN3OS, C15H17N3O2, and C13H14N2O3, respectively. The primary biological activities of these compounds were evaluated in vitro by the DPPH assay, H2O2-induced oxidative stress injury assay, and cytotoxicity assay. The results indicated that compounds C1, C2, C4, C7, and C9 exhibited DPPH·scavenging ability, while C3, C4, C5, and C8 showed potent growth-inhibitory activities against various human tumor cells, including MDA-MB-231, Hela, A549, and HT29. Interestingly, compound C4 showed potent scavenging effects on the DPPH radical and possessed protective effect on H2O2-induced oxidative stress injury in human neuroblastoma SH-SY5Y cells at low concentrations; however, C4 exhibited significant toxicity against four human tumor cells at a higher concentration in all treatments, and the range of IC50 value was 7.91 to 13.35 μM. 相似文献
16.
相位锁定是双模压缩微波制备的关键问题之一.针对基于超导180°混合环的制备方案相位稳定度不高且信息处理复杂等问题,提出一种相位锁定方案.对约瑟夫森参量放大器的信号输入进行相位调制,输出的单模压缩微波与另一未调制的同频单模压缩微波在超导180°混合环内干涉,实现双模压缩微波的制备与路径分离.将未调制的单模压缩微波与一路双模压缩微波混频,解调出相位调制信号可得到两路单模压缩微波的相对相位及误差,将相位误差反馈于约瑟夫森参量放大器的抽运实现相对相位的锁定,获得稳定的双模压缩输出.本研究对高性能纠缠微波源的设计提供了理论参考. 相似文献
17.
18.
Er3+,Ho3+和Tm3+在硫氧化钆中的余辉发光 总被引:1,自引:0,他引:1
The new Er^3 , Ho^3 and Tm^3 doped gadolinium oxysulfide phosphors with the long afterglow emission were synthesized by solid-state reaction method. The synthesized phosphors were characterized by X-ray diffraction. The excitation and photolumineseenee spectra, afterglow spectra and afterglow decay curve were examined by fluorescence spectroscopy. The afterglow spectra of Gd2O2S:Er^3 , Mg, Ti showed typical transitions of Er^3 at 528(2H11/2→4I15/2), 548 (^4S3/2 →^4I15/2) and 669 nm (^4F9/2→^4I15/2). In the afterglow spectra of Gd2O2S: Ho^3 , Mg, Ti,typical transitions of Ho^3 at 546 nm (^5S2→^5I8), 651 and 661 nm (^2F5→^5I8) were observed. In Gd2O2S:Tm^3 , Mg,Ti, the afterglow emission at 800 nm (^1G4→^3H5) of Tm^3 was seen. The meehnism and model of afterglow energy transfer were proposed. 相似文献
19.
20.
半导体光催化剂的表面修饰 总被引:80,自引:5,他引:80
从半导体光催化剂表面修饰的类型、机理及效果出发,对其研究进展作了综合评述. 相似文献