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81.
A double-recessed offset gate process technology for InP-based high electron mobility transistors (HEMTs) has been developed in this paper. Single-recessed and double-recessed HEMTs with different gate offsets have been fabricated and characterized. Compared with single-recessed devices, the maximum drain-source current (ID,max) and maximum extrinsic transconductance (gm,max) of double-recessed devices decreased due to the increase in series resistances. However, in terms of RF performance, double-recessed HEMTs achieved higher maximum oscillation frequency (fMAX) by reducing drain output conductance (gds) and drain to gate capacitance (Cgd). In addition, further improvement of fMAX was observed by adjusting the gate offset of double-recessed devices. This can be explained by suppressing the ratio of Cgd to source to gate capacitance (Cgs) by extending drain-side recess length (Lrd). Compared with the single-recessed HEMTs, the fMAX of double-recessed offset gate HEMTs was increased by about 20%. 相似文献
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84.
一种磺酰胺类碳酸酐酶Ⅱ抑制剂3D-QSAR分析新方法 总被引:1,自引:0,他引:1
提出了用Gaussian03量子化学计算软件优化磺酰胺类碳酸酐酶Ⅱ抑制剂分子的空间构型,得到相应的3D隐氢分子图、原子的标准定位坐标及其单点能.然后将3D分子隐氢图模拟成一个3D空间刚架元体系,通过求解该体系的无阻尼自由振动固有频率,得到分子体系的3D动态结构特征参量——基频ω0,并选择辅助基团中第一环路结构上取代基的节点顺序数NXm、元素种类数NE和分子单点能绝对值E0作为辅助参量建立QSAR模型,且用于文献报导的29种磺酰胺类碳酸酐酶Ⅱ抑制剂活性的定量结构-活性相关性分析,可得到多元线性回归方程:lgKc=-6.7960-25.3670ω0+2.2525NXm-0.6210NE+0.005779E0,其复相关系数r2大于0.99,其对数标准偏差S0.14,平均偏差小于0.112. 相似文献
85.
The title complex Ni3(C14H8N3O5)2(C5H5N)4 has been synthesized by the reaction of 2-hydroxy-N′-(4-nitrobenzoyl)benzohydraizide with nickel acetate in pyridine solution. Its molecular structure was characterized by elemental analysis, IR spectra and X-ray crystal structure determination. Crystal data for this compound: Mono-clinic, space group P21/c, Mr=1 089.00, a=0.249 27(5) nm, b=0.161 40(3) nm, c=0.121 81(2) nm, β=94.59(3)°, V=4.885 2(17) nm3, Z=4, Dc=1.481 Mg·m-3, F(000)=2 232, R1=0.049 7, wR2=0.106 8 (observed reflections with I>2σ(I)) and R1=0.105 1, wR2=0.119 4 (all reflections), GOF=1.021. The complex was evaluated for their antitumor activi-ties against two kinds of cell lines (K562 and BGC) by MTT method. A preliminary bioactivity study indicates that the complex shows distinct antitumor activity. CCDC: 627252. 相似文献
86.
光谱椭偏仪被用来研究用脉冲激光沉积方法在Si(100)基片上,温度分别为400,500,600,700 ℃制备的ZnO薄膜的特性。利用三层Cauchy散射模型拟合椭偏参数,计算了每个温度下制备的ZnO薄膜在400~800 nm波长范围内的折射率(n)和消光系数(k)。发现基片温度对光学常数有很大的影响。通过分析XRD表征的晶体结构和 AFM表征的薄膜表面形貌,发现折射率的变化归因于薄膜堆积密度的变化。为了获得具有较好的光学和薄膜质量的ZnO薄膜,相比与其他沉积温度600 ℃或许是最佳的沉积温度。 相似文献
87.
A-α-CAO induces weak analgesia with very short duration in mice and is able to antagonize the analgesic effect of morphine (Mor) up to 3—4 days after a single injection. No tendency of dependence has been observed. It acts as a partial agonist on MVD with Ke value of 9×10~(-9) mol/L. Its antagonist effect remains after several washes and its agonist effect cannot be reversed by naloxone (Nx), provided the incubation time or the concentration of the agent is sufficient. On isolated GPI, A-α-CAO is a pure agonist with IC_(50) of 5.7×10~(-10) mol/L; this agonist effect cannot be removed by washing but can be reversed by Nx. On RVD and RbVD, it has antagonist effect against β-endorphine (β-end) and US0488H, which cannot be washed out easily, and the pA_2are 7.5 and 7.6 respectively. A-α-CAO also inhibits the specific binding of ~3H-etorphine (~3H-Etor) to the P_2 fraction of the mouse brain membrane with an IC_(30) of 3.2×10~(-9) mol/L. The inhibition on the high affinity binding sites of ~3H-Etor 相似文献
88.
设计并制备了780 nm大功率半导体激光器的单管和巴条。采用金属有机化学气相沉积技术制备的外延结构,分别使用GaAsP和GaInP作为量子阱和波导层,限制层是具有高带隙的AlGaInP材料。量子阱与波导层带隙0.15 eV,波导层与限制层带隙0.28 eV,抑制了载流子泄露。1.55μm厚非对称大光学腔波导结构抑制快轴高阶模,同时缓解腔面损伤问题。为进一步提高腔面损伤阈值,利用超高真空解理和钝化技术,在腔面上沉积了非晶ZnSe钝化层。条宽150μm、腔长4 mm的单管器件,在电流为15 A时,输出连续功率16.3 W未出现COD现象,斜率效率达到1.27 W/A,电光转换效率为58%,慢轴发散角9.9°,光谱半高宽为1.81 nm。填充因子为40%的厘米巴条,在192 A下实现连续输出功率180 W,电光转换效率为50.7%,光谱宽度仅为2.2 nm。 相似文献
89.
本文叙述14.2±0.1MeV中子能量的137Ba(n,p)137Cs、136Ba(n,p)136Cs、134Ba(n,p)134Cs、132Ba(n,p)132Cs、134Ba(n,2n)133Ba和132Ba(n,2n)131Ba等反应截面的测量,测量方法采用以54Fe(n,p)54Mn和54Fe(n,a)51Cr反应为标准截面的相对活化法,并用现有的数据对本结果进行了比较. The cross sections of the 137Ba (n, p) 137Cs, 136Ba (n, p)136Cs, 134Ba (n, p ) 134Cs, 132Ba (n, p) 132Cs, 134Ba(n, 2n) 133Ba and 132Ba(n, 2n ) 131Ba reactions have been measured by using the activation method relative the cross sections of 54Fe(n, p ) 54Mn and 54Fe(n,a)51Cr reactions at the neutron energy of 14. 2 ±0. 1MeV. The results obtained are compared with the data on hand. 相似文献
90.