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991.
K. Shi X.L. Liu D.B. Li J. WangH.P. Song X.Q. XuH.Y. Wei C.M. JiaoS.Y. Yang H. SongQ.S. Zhu Z.G. Wang 《Applied Surface Science》2011,257(18):8110-8112
XPS was used to measure the energy discontinuity in the GaN/diamond heterostructure. The valence band offset (VBO) was determined to be 0.38 ± 0.15 eV and a type-II heterojunction with a conduction band offset (CBO) of 2.43 ± 0.15 eV was obtained. 相似文献
992.
Tianru WuHonglie Shen Bin ChengYuanyuan Pan Bing LiuJiancang Shen 《Applied Surface Science》2011,258(3):999-1003
In this work, hydrogenated amorphous silicon carbide (α-Si1−xCx:H) and nanocrystalline SiC (nc-SiC) thin films were deposited by hot wire CVD (HWCVD) using SiH4/C2H2/H2 gas mixtures. It was found that the films prepared under low gas pressure were α-Si1−xCx:H and those prepared under high gas pressure were nc-3C-SiC. The α-Si1−xCx:H films showed enhanced density of C-Hn and Si-C bonds with increasing C2H2 fraction, which induced an increase in optical gap from 1.8 to 3.0 eV. For the deposition process of nc-SiC, the Eg opt of the deposited films varied from 1.9 eV to 2.5 eV as the filament temperature increased from 1700 to 2100 °C. The deposition rate decreased rapidly from 5.74 nm/min to 0.8 nm/min with increasing TF. 相似文献
993.
V. SoleimanianS.R. Aghdaee 《Applied Surface Science》2011,258(4):1495-1504
The zinc oxide films were prepared by the sol-gel method on the ordinary glass substrates. The activity of slip systems were evaluated by X-ray diffraction line broadening analysis using convolution multiple whole profile (CMWP) fitting procedures. It was found that in all temperatures the 〈a〉 type dislocations is dominating and its fraction increases with the rise of annealing temperature in the range of 350-600 °C. The investigation on the optical properties of films showed that the optical band gap energy increases linearly with the annealing temperature and crystallite size but decreases with the lattice strain. 相似文献
994.
Tao Wang Yanmei Liu Qingqing FangMingzai Wu Xia SunFei Lu 《Applied Surface Science》2011,257(6):2341-2345
Al-doped ZnO (AZO) and (Al, Na) co-doped ZnO (ANZO) thin films were prepared via sol-gel technique with an annealing process at temperatures between 450 and 550 °C for 60 min in air ambient, and their structural and optical properties have been investigated. The deposited films exhibited hexagonal zinc oxide structure except annealing at 450 °C. For the 500 °C-annealed samples, the surface morphology was analyzed via scanning electron microscopy, Photoluminescence (PL) of different Na content ANZO thin films showed that there were very obvious violet and blue emission bands between 400 and 500 nm, and intensity of which were enhanced with Na content increasing. Transparency of the films was improved along with increasing Na content. The result of UV indicated the absorb bands appeared obviously red shift with Na doping into ZnO, the optical gaps of all films far beyond 3.37 eV of pure ZnO, and gradually decreased with Na content increasing, this is very virtual for improving photoelectricity performance of transparent conduct oxide (TCO) film. The possible origins responsible for structure and optical properties also had been discussed. 相似文献
995.
该文构建了玉米秸秆粗蛋白定量分析模型,并对光谱特征波段选取方法进行探讨及验证。首先对107个样本进行预处理,剔除两个异常样本后采用DB2小波缺省阈值4层分解方式进行光谱重构,预处理后粗蛋白模型交互验证决定系数R2CV从0.788 9提高至0.920 8,采用间隔偏最小二乘(IPLS)及其改进型方法后向区间间隔偏最小二乘(BIPLS)、组合间隔偏最小二乘(SIPLS)进行特征波段选取,并对比主成分分析、竞争性自适应重加权采样法、相关系数法、遗传算法、移动窗口最小二乘等结果,发现基于IPLS及其改进型BIPLS、SIPLS均可有效、准确定位特征波段区间,其中采用SIPLS 30 波段间隔在10 128~10 398 cm-1与11 196~11 462 cm-1时具有最优模型,验证集相关系数(rp)为0.978 4,验正集决定系数(R2P)为0.957 2,验正集均方误差根(RMSEP)为0.221 1,相比于其他波段选取方法表现出较好的实时准确性,该方法可为玉米秸秆氨碱化最优条件判定提供重要的数据支撑。 相似文献
996.
997.
Wen-Tong Chen 《Acta Crystallographica. Section C, Structural Chemistry》2020,76(5):375-380
A novel manganese(III)–porphyrin complex, namely, catena‐poly[[chloridomanganese(III)]‐μ2‐5,10,15,20‐tetrakis(pyridin‐3‐yl)‐21H,23H‐porphinato(2?)‐κ5N21,N22,N23,N24:N5], [MnCl(C40H24N8)]n, 1 , was prepared by the hydrothermal reaction of manganese chloride with 5,10,15,20‐tetrakis(pyridin‐3‐yl)‐21H,23H‐porphine. The crystal structure was determined by single‐crystal X‐ray diffraction. The porphyrin macrocycle exhibits a saddle‐like distortion geometry. The MnIII atom has a six‐coordination geometry. Each porphyrin unit links to two neighbouring units to yield a one‐dimensional coordination polymer. These chains are further interlinked by hydrogen bonds to form a two‐dimensional network. The complex shows red photoluminescence emission bands in ethanol solution, which can be attributed to ligand‐to‐ligand charge transfer (LLCT) accompanied by partial metal‐to‐ligand charge transfer (MLCT), as revealed by TDDFT calculations. 相似文献
998.
Yaokang Lv Dr. Jun Cheng Dr. Alexander Steiner Prof. Lihua Gan Prof. Dominic S. Wright 《Angewandte Chemie (International ed. in English)》2014,53(7):1934-1938
Metal‐doped polyoxotitanium cages are a developing class of inorganic compounds which can be regarded as nano‐ and sub‐nano sized molecular relatives of metal‐doped titania nanoparticles. These species can serve as models for the ways in which dopant metal ions can be incorporated into metal‐doped titania (TiO2), a technologically important class of photocatalytic materials with broad applications in devices and pollution control. In this study a series of cobalt(II)‐containing cages in the size range ca. 0.7–1.3 nm have been synthesized and structurally characterized, allowing a coherent study of the factors affecting the band gaps in well‐defined metal‐doped model systems. Band structure calculations are consistent with experimental UV/Vis measurements of the TixOy absorption edges in these species and reveal that molecular dipole moment can have a profound effect on the band gap. The observation of a dipole‐induced band‐gap decrease mechanism provides a potentially general design strategy for the formation of low band‐gap inorganic cages. 相似文献
999.
Superconducting Double Perovskite Bismuth Oxide Prepared by a Low‐Temperature Hydrothermal Reaction
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Mirza H. K. Rubel Prof. Akira Miura Prof. Takahiro Takei Prof. Nobuhiro Kumada M. Mozahar Ali Prof. Masanori Nagao Prof. Satoshi Watauchi Prof. Isao Tanaka Prof. Kengo Oka Prof. Masaki Azuma Prof. Eisuke Magome Prof. Chikako Moriyoshi Prof. Yoshihiro Kuroiwa Prof. A. K. M. Azharul Islam 《Angewandte Chemie (International ed. in English)》2014,53(14):3599-3603
Perovskite‐type structures (ABO3) have received significant attention because of their crystallographic aspects and physical properties, but there has been no clear evidence of a superconductor with a double‐perovskite‐type structure, whose different elements occupy A and/or B sites in ordered ways. In this report, hydrothermal synthesis at 220 °C produced a new superconductor with an A‐site‐ordered double perovskite structure, (Na0.25K0.45)(Ba1.00)3(Bi1.00)4O12, with a maximum Tc of about 27 K. 相似文献
1000.
采用水合肼(N2H4·H2O)作为还原剂,在液相环境中制备了自掺杂TiO2纳米管阵列(NTs)。利用FE-SEM、EDS、XPS、XRD、Raman、UV-Vis/NIR分光光度法以及半导体特性分析系统(Keithley 4200 SCS)分别对样品的形貌,晶体结构,光学特性以及电学性能进行了表征。结果表明:通过这种方法制备的自掺杂TiO2NTs在带隙中引入了大量的氧空位,创造了氧空位能级,从而提高了样品的电导率,有效提高光生电子-空穴对的产生、分离和传输。此外,由于氧空位的作用,使得TiO2NTs的带隙变窄,增强了可见光吸收能力,致使样品具有较高的光催化活性,并通过降解甲基橙溶液对样品的光催化活性进行评估。结果显示当光照150 min后,自掺杂TiO2NTs对甲基橙溶液的降解率达73%,并且这种催化剂便于回收和重复使用。 相似文献