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71.
B.K. Agrawal Savitri Agrawal 《Physica E: Low-dimensional Systems and Nanostructures》2005,30(1-2):7-12
An ab-initio study of the effects of the quantum confinement has been performed for the first time in the ultrathin ZnS films: unpassivated, passivated and the Mn-doped ones. A self-consistent full potential linear muffin tin orbital (FP-LMTO) method has been employed. The studied films have comparatively a large thickness range of 2.7–29.7 Å. The fundamental band gap increases exponentially with decrease in the size of the quantum confinement. The Mn-doped films reveal the localized impurity-induced states within the band gap and also in the conduction band region. The intense optical transitions between the Mn-induced states will appear at about 2.1 eV which is in excellent agreement with the observed peak in the photoluminescence experiments. 相似文献
72.
报道了对一系列不同组份的ZnSxTe1-x(0≤x〈1)混晶的喇曼菜射和光致姚研究,室温下的喇曼散实验结果表明ZnSxTe1-x中的声子具有双模行为,研究了ZnSxTe1-x混晶的反射谱,背散射和边发射配置下的光致发光谱,以及10~300K温度范围内光至发光谱的温度关系,结果表明:x较小时,ZnSxTe1-x的发光来源于混晶带边发光或浅杂质的发光,x接近1时,发光蜂来源于束缚在Te等电子自陷激子的 相似文献
73.
介绍了光化学汽相淀积法的原理以及PVD-1000设备淀积薄膜的规律,特点等,并且给出了所淀积的SiO2膜,Si3N4膜和ZnS膜的基本特性。 相似文献
74.
The photo (PL) and electro (EL) luminescence in ZnS: MnLa and ZnS: La have been studied. The enhancement and quenching of
emission bands have been observed on the simultaneous application of sinusoidal field and photons. The wave shape, voltage,
frequency and temperature dependence of EL brightness have been reported. A study of the phosphorescence and thermoluminescence
of these phosphors is also carried out and it is observed that the trap-depth changes slowly with temperature and activator
concentration. An attempt has been made to calculate the trap depth by studying temperature dependence of EL brightness. The
results are reported and discussed. 相似文献
75.
J. E. Yu K. S. Jones P. H. Holloway B. Pathangey E. Bretschneider T. J. Anderson S. S. Sun C. N. King 《Journal of Electronic Materials》1994,23(3):299-305
A temperature and flow modulation (TFM) technique has been developed to modulate the manganese doping profile in ZnS phosphor
material grown by lowpressure metalorganic chemical vapor deposition for alternating-current thin film electroluminescent
devices (TFELDs). In the TFM technique, modulation of both the substrate temperature as well as the flows of metalorganic
sources, diethylzinc and tricarbonyl-(methylcyclopentadienyl)-manganese (TCPMn), was used to grow a structure consisting of
alternating layers of undoped ZnS at 400°C and Mn-doped ZnS where Mn being incorporated into the undoped ZnS at 550°C. X-ray
results indicated that MnSx phases were present within the ZnS host crystal matrix for the modulation doped samples, while a MnxZn1-xS solid solution was present in the uniformly doped samples. The luminescence efficiency of the TFELDs could be modified by
growing the phosphor with dopant (luminescent center) modulation. The TFELDs with a single modulated doping phosphor layer
showed lower threshold voltages in the range 70 to 80 V with light emission in the 580 to 587 nm wavelength range. With a
twofold increase in the total thickness of the undoped ZnS layer, the brightness and the luminescence efficiency, measured
at the threshold voltage plus 40 V, increased by a factor of 20 and 10, respectively. The electroluminescent (EL) characteristics
of the phosphors with multiple dopant layers showed higher luminescence efficiency. By using the TFM growth technique, one
can engineer the luminescent center distribution in the phosphor layer to improve the EL characteristics. 相似文献
76.
报道了水热法(200℃)直接合成的ZnS:Cu,Al纳米晶及其发光特性.ZnS:Cu,Al纳米晶粒径约15 nm,尺寸分布窄,分散性好,具有纯立方相的类球形结构.借助X射线能谱法(EDX)和原子吸收光谱仪,研究了样品中S,Zn和Cu的含量并详细研究了光致发光(PL)光谱的特性.结果证明存在大量Zn空缺,Cu离子经过水热处理后已掺入到ZnS基体中.PL光谱特性为:样品的激发谱为宽带谱,337 nm激发时样品发出很强的绿光,370~420 nm之间任意波长激发时,发射谱均为宽带谱,且它们基本重合.表明此材料作为近紫外(370~410 nm)发光二极管((n)-UV(370~410 nm)LED)用荧光粉及全色荧光粉具有很大的应用潜力.样品在375 nm激发下全色宽带发射谱是460,510和576 nm带光谱的高斯叠加.当Cu/Zn,Cu/Al和S/Zn分别为3×10-4,2和3.0时,于室内照明条件下肉眼可观察到白色发光. 相似文献
77.
Shuping Zhang 《Optik》2010,121(4):312-316
The photoluminescence (PL) properties of the guest-host films, using CdTeS/ZnS core shell quantum dots (QDs) as the guest and organic small-molecule material Alq3 as the host, are studied by steady-state and time-resolved PL spectroscopy. Both the relative intensity and the PL lifetime are intensively dependent on the weight ratio of Alq3 and CdTeS/ZnS QDs. The detailed analysis provides clear evidence for a Förster energy transfer from Alq3 host to QDs guest, based on the nonradiative resonant transfer mechanism. The results are relevant to the application of hybrid organic/inorganic systems to OLEDs. 相似文献
78.
Y. Zhang X.Y. Dang J. Jin T. Yu B.Z. Li Q. He F.Y. Li Y. Sun 《Applied Surface Science》2010,256(22):6871-6875
In this combined film thickness, scanning electron microscopy (SEM), X-ray diffraction and optical properties study, we explore the effects of different stirring speeds on the growth and optical properties of ZnS film deposited by CBD method. From the disclosed changes of thickness of ZnS film, we conclude that film thickness is independent of the stirring speeds in the heterogeneous process (deposition time less than 40 min), but increases with the stirring speeds and/or deposition time increasing in the homogeneous process. Grazing incident X-ray diffraction (GIXRD) and the study of optical properties disclosed that the ZnS films grown with different stirring speeds show partially crystallized film and exhibit good transmittance (70-88% in the visible region), but the stirring speeds cannot give much effects on the structure and optical properties in the homogeneous process. 相似文献
79.
对不同温度下沉积的ZnS薄膜的结晶情况和光学特性进行了研究, 结果表明:沉积温度对ZnS薄膜的物理和光学特性有较大影响, 不同的温度沉积的ZnS薄膜具有不同的择优取向, 牢固度也大不相同; 不同沉积温度下, ZnS薄膜的光学常数也不尽相同. 温度为115 ℃和155 ℃时, ZnS薄膜的物理性能和光学性能较差, 不适合空间用光学薄膜的研制使用. 而190 ℃和230 ℃沉积温度下所得薄膜具有较好的物理和光学性能, 适合于不同要求的空间用薄膜器件的研制使用.
关键词:
硫化锌薄膜
沉积温度
表面形貌
光学常数 相似文献
80.