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971.
研究了18-冠-6与Na2[Cu(i-mnt)2][i-mnt=异丁二腈烯二硫醇阴离子,S2CC(CN)2-2]的反应,得到的配合物[Na(18-C-6)]2[Cu(i-mnt)2](1)通过元素分析、红外光谱、X射线单晶衍射进行了结构分析.配合物为单斜晶系,空间群P2(1)/c.晶体学结构数据a=1.2819(11),b=1.1793(10),c=1.4928(13)nm,β=99.121(16)°,V=2.228(3)nm3,Z=2,Dcaled.=1.369g/cm3,F(000)=958,R1=0.0521,wR2=0.1003.1中的[Cu(i-mnt)2]基团通过配体i-mnt的氮原子与两个[Na(18-C-6)]基团中的钠原子成键,形成稳定的中性配合物. 相似文献
972.
973.
Yuancong Zhao 《Applied Surface Science》2010,257(5):1596-1601
Crystalline TiO2 films were prepared by unbalanced magnetron sputtering and the structure was confirmed by XRD. An organic layer of 11-hydroxyundecylphosphonic acid (HUPA) was prepared on the TiO2 films by self-assembling, and the HUPA on TiO2 films was confirmed by FTIR analysis. Simultaneously, hydroxyl groups were introduced in the phosphonic acid molecules to provide a functionality for further chemical modification. 2-Methacryloyloxyethyl phosphorylcholine (MPC), a biomimetic monomer, was chemically grafted on the HUPA surfaces at room temperature by surface-initiated atom-transfer radical polymerization. The surface characters of TiO2 films modified by poly-MPC were confirmed by FTIR, XPS and SEM analysis. Platelet adhesion experiment revealed that poly-MPC modified surface was effective to inhibit platelet adhesion in vitro. 相似文献
974.
975.
运用Gaussian 03程序包中的单双迭代三重激发耦合簇理论和相关一致五重基优化了AsH_2的基态结构,并在优化结构的基础上计算了它的离解能和振动频率.结果表明:AsH_2基态的平衡构型具有C_(2v)对称性,键长R_(As-H)=0,1508 nm,键角∠HAsH=91.2231°,离解能D_e(Has-H)=2.8795 eV,振动频率ν_1(α_1)=1013.3361 cm~(-1),ν_2(α_1)=2225.1347 cm~(-1),ν_3(α_1)=2233.7565 cm~(-1).这些结果与实验值较为相符.对H_2的基态使用优选出的cc-pV6Z基组、对AsH的基态使用优选出的cc-pV5Z基组进行平衡几何与谐振频率的计算并进行单点能扫描,且将扫描结果拟合成了Murrell-Sorbie函数.与实验数据及其他理论结果的比较表明,本文关于AsH(X~3∑~-)自由基光谱常数(D_0,D_e,R_e,ω_e,B_e,α_e和ω_eX_e)的计算结果达到了很高的精度并最为完整.采用多体项展式理论导出了AsH_2(C_(2v),X~2B_1)自由基的解析势能函数,其等值势能图准确再现了它的离解能和平衡结构特征.首次报导了AsH_2(C_(2v),X~2B_1)自由基对称伸缩振动等值势能图中存在的两个对称鞍点,对应于反应AsH+H→ABH_2,势垒高度约0.1512×4.184 kJ/mol.Abstract: The CCSD(T) theory in combination with the cc-pV5Z basis set is used to determine the equilibrium geometry, dissociation energy and vibrational frequencies of AsH_2 (C_(2v), X~2B_1) radical. By comparison, excellent agreement can be found between the present results and the experiments. The values obtained at present are of 0.1508 ran for the equilibrium bond length R_(As-H), 91.2231° for the bond angle ∠ HASH, 2. 8795 eV for the dissociation energy D_e (HAs-H) and 1013.3361 cm~(-1), 2225.1347 cm~(-1) and 2233.7565 cm~(-1) for the vibrational frequencies ν_1(α_1), ν_2(α_1) and ν_3(α_1), respectively. The equilibrium geometry,harmonic frequency and potential energy curve of the AsH(X~3∑~-) radical are calculated at the CCSD(T)/cc-pV5Z level of theory. The ab initio results are fitted to the Murrell-Sorbie function with the least-square method. The spectroscopic parameters are in excellent agreement with the experiments. The analytic potential energy function of the AsH_2 (C_(2v), X~2 B_1) radical is derived by using the many-body expansion theory. This function correctly describes the configuration and dissociation energy of the AsH_2 (C_(2v), X~2B_1) radical. Two symmetrical saddle points have been found at (0.160 nm,0.296 nm) and (0.296 nm,0.160 nm) ,respectively. And the barrier height is equal to 0.1512×4.184 kJ/mol. 相似文献
976.
Ultrafine particles of BaMgAl10O17:Eu2+ (BAM) phosphor were synthesized by a solid-state combustion reaction in a powder bed of 0.9BaCO3+MgO+5Al2O3+0.05Eu2O3+k(KClO3+1.5C) composition. A large exothermic reaction of the mixture (KClO3+1.5C) leads to a self-sustaining combustion mode. Under optimized combustion conditions, the product consisted of BAM powder and KCl was obtained. BAM ultrafine particles resulting from the combustion process were easily obtained by simply washing the salt by-product with water. Combustion-processed BAM phosphor shows a homogeneous grain size of 100-500 nm, good dispersity, regular morphology, and improved luminescence properties. 相似文献
977.
Jen-Hwan Tsai 《Journal of luminescence》2010,130(10):1680-1686
In this paper, a shift in the photoluminescence (PL) peak from blue to near-infrared region was observed in the Si+-implanted 400-nm-thick SiO2 films with the rapid thermal annealing (RTA) method only. As the Si+-fluence was 1×1016 ions/cm2, a blue band was observed in the films after RTA at 1050 °C for 5 s in dry-N2 atmosphere; then, the band shifted from blue to orange upon increasing the holding temperature of RTA to 1250 °C in the films after the isochronal RTA in dry N2. Furthermore, while the fluence was increased to 3×11016 ions/cm2 and the holding temperature was at the same range between 1050 and 1250 °C, the PL peak occurred between red and near-infrared regions. Although the RTA and conventional thermal annealing (CTA) methods produce a similar mechanism, the CTA method needs a much longer annealing-time and a higher Si+-implanted dose than the RTA method for producing the same shift and intensity of PL peak from the as-implanted sample. Therefore, the RTA method can produce the mechanism in the Si+-implanted sample with the PL energy between blue and near-infrared band in place of the CTA method. 相似文献
978.
连续CO2激光对红外窗口材料损伤研究 总被引:4,自引:0,他引:4
研究了连续CO2激光对几种红外窗口材料的表面损伤特性,研究表明,损伤机制在于杂质缺陷吸收造成的热冲击应力破坏。深入研究了杂质缺陷密度、焦斑与材料损伤阈值的关系,并建立了一个损伤模型。同时分析了热冲击应力破坏方式。 相似文献
979.
980.
2×2列联表中二属性相关的假设检验是定性数据分析中的热点问题,针对此问题的研究频率学派已做过大量的工作,其理论方法已趋于成熟.利用Bayes检验研究2×2列联表中二属性的相关性迄今为止国内外的相关文献还为数不多.将依据Bayes理论对此问题提出新的检验方法,推出其Bayes因子计算公式,利用正态近似研究三项假设计算出有关的后验概率,不仅解决了频率学派难以处理的问题,并且为吸烟有害健康提供了理论支撑. 相似文献