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61.
高温退火后掺铁半绝缘(SI)InP单晶转变为n型低阻材料.利用霍尔效应(Hall),热激电流谱(TSC),深能级瞬态谱(DLTS),X射线衍射等方法分别研究了退火前后InP材料的性质和缺陷.结果表明受高温热激发作用部分铁原子由替位转变为填隙,导致InP材料缺少深能级补偿中心而发生导电类型转变.通过比较掺杂、扩散和离子注入过程Fe原子的占位和激活情况分析了这一现象的机理和产生原因.
关键词:
磷化铟
铁激活
退火
半绝缘 相似文献
62.
63.
The dispersions of low energy surface phonon modes of GaP(1 1 0) and InAs(1 1 0) measured with inelastic He-atom scattering along the
and 0 0 1 directions are presented. Aside from the Rayleigh mode, additional distinct acoustic modes are observed as well as indications of optical modes. Contrary to results for GaAs(1 1 0), a rocking mode was not observed. The experimentally determined phonon dispersions are in excellent agreement with recent ab initio calculations by C. Eckl, et al. [1]. 相似文献
64.
A novel route for synthesis of NiCoP/SiO2 hydrodesulfurization catalysts with active S species 下载免费PDF全文
We report a new route for synthesis of NiCoP/SiO2 with active S species using NiS and CoS as precursors. The as‐prepared catalysts were characterized using X‐ray powder diffraction, N2‐adsorption specific surface area measurements, inductively coupled plasma atomic emission spectroscopy, transmission electron microscopy, and X‐ray photoelectron spectroscopy (XPS). The catalyst was highly active during the dibenzothiophene hydrodesulfurization (HDS) of NiCoP/SiO2. The XPS spectra of the as‐obtained samples show that the surface of NiCoP contains a small amount of S species, which may be responsible for the higher HDS activity. 相似文献
65.
Peter Eliáš Stanislav Hasenöhrl Agáta Laurencíková Alica Rosová Jozef Novák 《固体物理学:研究快报》2014,8(4):321-324
GaP(111)B substrate was strewn with 30 nm colloidal Au nanoparticles. Organic residues were removed by: A) boiling in acetone and isopropylalcohol followed by a DI water rinse, B) treatment A + HF:H2O, C) treatment A + O2 plasma for 10 min, 20 min, and 40 min, and D) treatment A combined with O2 plasma (10 min) and HF:H2O. The substrate thus had original ‘epi‐ready' oxides (A), or fresh native oxides (B and D), or new added oxides (C). The samples were annealed at Ta = 650 °C for 10 min under PH3 and H2 in an MOVPE chamber. This resulted in the growth of GaP stumps along [111]B on each sample. Their length was <3 nm (B and D), ~20 nm (A), and ~220 nm (C 40 min). Elemental Ga is left as P2O5/Ga2O3 oxides form on etched GaP(111)B at room temperature. We believe that as the oxides disintegrated during annealing, they released the elemental Ga that combined with phosphorus from PH3, and this led to the growth of the GaP stumps. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
66.
在低还原温度下程序升温还原法制备了Ni2P/MCM-41催化剂,并采用H2-TPR、TG-DTG、XRD、BET、XPS等手段对制备的催化剂进行了表征,考察了还原温度对活性相Ni2P形成以及催化剂二苯并噻吩HDS性能的影响。结果表明,在210~390℃下还原得到的催化剂活性相为单一的Ni2P相;在390℃下还原得到的催化剂具有最高的二苯并噻吩HDS活性,在反应温度340℃、反应压力3.0 MPa、氢/油体积比500、质量空速(WHSV)2.0 h-1的条件下二苯并噻吩HDS转化率达到99.0%。 相似文献
67.
使用TiO2、Al2O3以及TiO2-Al2O3复合载体考察了载体对磷化镍催化剂活性相和加氢脱氮性能的影响。不同钛铝原子比的TiO2-Al2O3复合载体采用原位-溶胶凝胶法制备,负载的磷化镍催化剂采用等体积浸渍法和H2原位还原法制备。以喹啉为模型化合物在固定床反应器上对催化剂的加氢脱氮性能进行评价,采用XRD、N2吸附、TEM和H2-TPR等技术对催化剂和载体进行了表征。结果表明,制成的复合载体基本保留了最初引入的γ-Al2O3的孔特征,分散在γ-Al2O3表面的TiO2以锐钛矿晶型存在。不同载体对催化剂的H2还原行为有显著影响,所形成的活性物种也不相同。Al2O3中引入TiO2可以减弱P物种和Al2O3之间的相互作用,有利于Ni2P活性相的生成和催化活性的提高。当Ti/Al的原子比为1∶8时,Ni2P/TiO2-Al2O3催化剂比Ni2P/TiO2、Ni2P/Al2O3催化剂具有更高的加氢脱氮活性。 相似文献
68.
以两种类型的TiO2(锐钛矿anatase、晶须载体whiskers)为载体,分别采用程序升温还原(H2-TPR)法和溶剂热法制备Ni2P/TiO2催化剂,并用X射线衍射(XRD)、N2吸附比表面积(BET)测定、N2等温吸附脱附、CO吸附表征、X射线光电子能谱(XPS)技术、扫描电镜(SEM)对催化剂的结构和性质进行了表征。考察了不同的制备方法及不同类型TiO2载体对Ni2P/TiO2催化剂二苯并噻吩(DBT)加氢脱硫(HDS)性能的影响。结果表明,溶剂热法制备催化剂过程中,保持了TiO2晶体结构,抑制了TiPO4的形成,HDS活性高于H2-TPR法制备的催化剂;与锐钛矿TiO2为载体的催化剂相比,以晶须TiO2为载体的催化剂具有更优良的表面性质,能生成较多晶体颗粒粒径较小、分散性好的Ni2P活性相,具有更高的HDS活性。以晶须TiO2为载体,采用溶剂热法制备的Ni2P/TiO2催化剂,具有最好的加氢脱硫活性,在340℃、3.0MPa、氢油体积比为500、质量空速(WHSV)2.0h-1的条件下,二苯并噻吩转化率达到为98.2%。 相似文献
69.
Erping Cao Zhimin Chen Hao Wu Peng Yu Ying Wang Fei Xiao Shuo Chen Shichao Du Ying Xie Yiqun Wu Zhiyu Ren 《Angewandte Chemie (International ed. in English)》2020,59(10):4154-4160
Even though transition‐metal phosphides (TMPs) have been developed as promising alternatives to Pt catalyst for the hydrogen evolution reaction (HER), further improvement of their performance requires fine regulation of the TMP sites related to their specific electronic structure. Herein, for the first time, boron (B)‐modulated electrocatalytic characteristics in CoP anchored on the carbon nanotubes (B‐CoP/CNT) with impressive HER activities over a wide pH range are reported. The HER performance surpasses commercial Pt/C in both neutral and alkaline media at large current density (>100 mA cm?2). A combined experimental and theoretical study identified that the B dopant could reform the local electronic configuration and atomic arrangement of bonded Co and adjacent P atoms, enhance the electrons’ delocalization capacity of Co atoms for high electrical conductivity, and optimize the free energy of H adsorption and H2 desorption on the active sites for better HER kinetics. 相似文献
70.
Phosphine and tertiarybutylphosphine adsorption on the indium-rich InP (0 0 1)-(2 × 4) surface at 25 °C have been studied by internal reflection infrared spectroscopy, X-ray photoelectron spectroscopy, and low energy electron diffraction. Both molecules form a dative bond to the empty dangling bonds on the In-P heterodimers and the second-layer In-In dimers and vibrate symmetrically at 2319 (2315) and 2285 (2281) cm−1 and asymmetrically at 2339 (2339) and 2327 (2323) cm−1. A fraction of these species dissociate into adsorbed PH2 with the hydrogen and tertiarybutyl ligands transferring to nearby phosphorus sites. The calculated energy barriers for desorption (<11 kcal/mol) of these molecules is less than that for dissociation (>17 kcal/mol) and explains their low sticking probabilities at elevated temperatures under InP growth conditions. 相似文献