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801.
Habibul Arfin Jagjit Kaur Tariq Sheikh Assist. Prof. Sudip Chakraborty Assoc. Prof. Angshuman Nag 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(28):11403-11407
Bi3+ and lanthanide ions have been codoped in metal oxides as optical sensitizers and emitters. But such codoping is not known in typical semiconductors such as Si, GaAs, and CdSe. Metal halide perovskite with coordination number 6 provides an opportunity to codope Bi3+ and lanthanide ions. Codoping of Bi3+ and Ln3+ (Ln=Er and Yb) in Cs2AgInCl6 double perovskite is presented. Bi3+-Er3+ codoped Cs2AgInCl6 shows Er3+ f-electron emission at 1540 nm (suitable for low-loss optical communication). Bi3+ codoping decreases the excitation (absorption) energy, such that the samples can be excited with ca. 370 nm light. At that excitation, Bi3+-Er3+ codoped Cs2AgInCl6 shows ca. 45 times higher emission intensity compared to the Er3+ doped Cs2AgInCl6. Similar results are also observed in Bi3+-Yb3+ codoped sample emitting at 994 nm. A combination of temperature-dependent (5.7 K to 423 K) photoluminescence and calculations is used to understand the optical sensitization and emission processes. 相似文献
802.
卤化物钙钛矿不仅具有光吸收系数高、激子束缚能低、载流子迁移率高等优异的光电性能,而且具有缺陷容忍度高、低温溶液法生长、带隙可调等传统半导体不具备的优点,迅速成为光电领域的研究热点之一。 在单个光电器件的基础上,开发阵列型器件将推动卤化物钙钛矿在(柔性)光电器件中的应用。 但卤化物钙钛矿因对常规有机溶剂较敏感而与现有光刻工艺不兼容,开发适合卤化物钙钛矿的微纳制作工艺尤为重要。 本文系统归纳了近年卤化物钙钛矿微纳阵列制备采用的各种策略和方法,分析了不同方法的优缺点和适用性,介绍了卤化物钙钛矿微纳阵列在光电领域的应用,并对该领域目前存在的问题及发展前景进行了展望,以期为新型卤化物钙钛矿光电器件的研究提供参考。 相似文献
803.
Jie-Hui Yu 《Journal of solid state chemistry》2007,180(2):518-522
From the simple hydro/solvothermal reactions, two 1:1 adducts of MX2 and piperazine (pip) [CdI2(pip)] 1 and [CoCl2(pip)] 2 were prepared. Both were characterized by elemental analyses, IR spectra, ultra-violet visible spectra, thermogravimetric analyses and X-ray single-crystal diffraction. With pip as the bridges, the 1-D linear CdI2 chains are extended into a 2-D layered compound 1, while the mononuclear CoCl2 units are linked into a 1-D zigzag-type chain compound 2. The fluorescence emission spectrum indicates that compound 1 possesses fluorescence property with the peaks at 373 nm () and 410 nm (). 相似文献
804.
针对传统方法难以制作结构光三维投影测量设备的灰度正弦光栅元件,并以Ronchi光栅代替从而影响测量准确度,提出了一种制作灰度按正弦分布的光栅模板的新方法.通过对银盐全息干板透过率特性曲线的理论分析,指出在对比度为一的正弦干涉条纹下曝光不能得到线性记录和变换的原因,并提出了采用均匀非相干光预曝光提供偏置点来实现线性记录的新方法.实验表明,采用空间滤波法能够获得对称双光束正弦干涉条纹记录,并准确控制正弦干涉条纹曝光在干板的线性区域,可以达到线性记录并获得尽可能高的反衬度. 相似文献
805.
Michael Veith Sanjay Mathur Volker Hugh 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):493-496
New heterotrimetallic alkoxide [{Cd(OPri)3}Sr{Zr2(OPri)9}]2 (1) is obtained quantitatively in an anion-exchange reaction involving well-characterised iodide heterobimetallic alkoxide ICd{Zr2(OPri)9} and the alkali metal reagent KSr(OPri)3. The formation of 1 is accompanied with an exchange of metals (Cd(II) and Sr(II)) between the constituting fragments (‘Cd{Zr2(OPri)9}+’ and ‘Sr(OPri)3 ?’) and the chelating Zr2(OPri)9 ? anion, in 1, coordinates to Sr2+ in contrast to the precursor ICdZr2(OPri)9 where it is bound to Cd2+. The heterotrimetallic nature of 1 is unambiguously established by multinuclear (1H, 13C and 113Cd) NMR spectral data and a single crystal X-ray diffraction analysis. 相似文献
806.
807.
AlCl3 · 6H2O/KI/CH3CN/H2O, an efficient and versatile system, cleaves the C–O bonds of esters, acetals, ethers, and oxathiolanes to the corresponding acids, alcohols, and carbonyl compounds chemoselectively at 80 °C in hydrated media with good yields. This system also converts the alcohols (primary/secondary) to halides and oxidizes the alcohols (primary/secondary) to the corresponding carbonyl compounds in the presence of DMSO. 相似文献
808.
We synthesized and characterized a series of oligo(phenyl-amide-triazole)s that can fold into a helical conformation guided by halide ions. Their binding models and affinities are highly dependent on the length of the foldamer, media and the inducing capability of halide ions. The short foldamer with one helical turn shows a 1:1 binding stoichiometry to all halides, while the longer foldamer with two or three helical turns in principle can form 1:2 complexes with chloride anions even bromide anions with an enhancement on binding affinities. A result of quantitative NOE calculations imply that the longer foldamer should increase its helical pitch so as to release the electrostatic repulsion between halide ions. 相似文献
809.
卤化银微晶中光电子衰减谱的特性 总被引:2,自引:1,他引:1
光电子在卤化银材料潜影形成过程中发挥着重要的作用 ,光电子衰减行为在很大程度上决定于卤化银的晶体结构。采用光学与微波双共振技术 ,测量了自由光电子和浅俘获光电子的衰减谱 ,得到了卤化银中电子陷阱的密度和深度分布。以自由光电子寿命为纽带 ,通过分析掺杂卤化银晶体中电子陷阱的分布情况 ,可以确定浅电子陷阱掺杂剂的最佳掺杂浓度。 相似文献
810.
This paper presents a review of the experimental and theoretical investigations of halogen interaction with metal surfaces. The emphasis was placed on the recent measurements performed with a scanning tunneling microscope in combination with density functional theory calculations. The surface structures formed on metal surface after halogen interaction are classified into three groups: chemisorbed monolayer, surface halide, bulk-like halide. Formation of monolayer structures is described in terms of surface phase transitions. Surface halide phases are considered to be intermediates between chemisorbed halogen and bulk halide. The modern theoretical approaches in studying the dynamics of metal halogenation reactions are also presented. 相似文献