首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   123篇
  免费   2篇
化学   78篇
晶体学   1篇
力学   1篇
数学   2篇
物理学   43篇
  2023年   3篇
  2022年   12篇
  2021年   5篇
  2020年   5篇
  2019年   6篇
  2018年   5篇
  2017年   3篇
  2016年   3篇
  2015年   1篇
  2014年   4篇
  2013年   10篇
  2012年   5篇
  2011年   7篇
  2010年   5篇
  2009年   10篇
  2008年   11篇
  2007年   7篇
  2006年   5篇
  2005年   1篇
  2004年   2篇
  2003年   1篇
  1997年   1篇
  1991年   2篇
  1990年   1篇
  1989年   3篇
  1981年   1篇
  1979年   1篇
  1978年   1篇
  1976年   2篇
  1950年   2篇
排序方式: 共有125条查询结果,搜索用时 15 毫秒
81.
82.
We develop generalized coherent states based on the Gazeau–Klauder formalism for the triangular well potential and discuss some of their properties. We study the Mandel parameter and the second-order correlation function for investigating the statistical properties. Moreover, we present the spatiotemporal evolution.  相似文献   
83.
84.
85.

Rapid liquid chromatographic procedures for analytical quality control of pharmaceutical preparations and human serum containing antihistamine drugs, meclizine and buclizine alone or in combination with pyridoxine are proposed, using acetonitrile:water (80:20) as a mobile phase (pH adjusted to 2.6), methylparaben as internal standard and UV detection was made at 230 nm. The results obtained showed a good agreement with the declared content. The method shows good linearity in the range of 30–10,000 ng mL−1 for pyridoxine and 25–10,000 ng mL−1 for meclizine and buclizine serum concentrations with a correlation coefficient 0.9999 (inter- and intra-day CV < 3.91%). The recovery was >97.8%. The proposed method may be used for the quantitative analysis of meclizine and buclizine alone or in combination with pyridoxine from raw materials, in bulk drugs, dosage formulations and in serum.

  相似文献   
86.
We propose two schemes for engineering cavity field cluster and GHZ states. The schemes are based on multiport atom interferometry in the Bragg-regime cavity QED. The second-order off-resonant Bragg diffraction of two-level atoms is utilized for generating the desired state. The derived schematics are shown to be experimentally feasible under the prevailing cavity QED research scenario.  相似文献   
87.
We present the recurrence phenomena of an initially localized wavepacket as a foundation to the quantum clock. Various recurrence times in a multidimensional system serve as arms of the clock. The quantum clock so designed may provide the best precision and make the measurement of time possible to the smallest scale.  相似文献   
88.
Cold atoms bouncing on a modulated atomic mirror exhibit dynamic localization and acceleration subject to modulated strength. We explain the characteristics of acceleration using accelerated mapping and define control parameters. We show that the effective Planck’s constant plays a vital role in limiting overall linear growth of accelerated atoms with time. For large values of the effective Planck’s constant, the atomic quantum accelerated is seized if the localization window overlaps the accelerated window.  相似文献   
89.
Fluorescent molecules absorb photons of specific wavelengths and emit a longer wavelength photon within nanoseconds. Recently, fluorescent materials have been widely used in the life and material sciences. Fluorescently labelled heterocyclic compounds are useful in bioanalytical applications, including in vivo imaging, high throughput screening, diagnostics, and light-emitting diodes. These compounds have various therapeutic properties, including antifungal, antitumor, antimalarial, anti-inflammatory, and analgesic activities. Different neutral fluorescent markers containing nitrogen heterocycles (quinolones, azafluoranthenes, pyrazoloquinolines, etc.) have several electrochemical, biological, and nonlinear optic applications. Photodynamic therapy (PDT), which destroys tumors and keeps normal tissues safe, works in the presence of molecular oxygen with light and a photosensitizing drugs (dye) to obtain a therapeutic effect. These compounds can potentially be effective templates for producing devices used in biological research. Blending crown compounds with fluorescent residues to create sensors has been frequently investigated. Florescent heterocyclic compounds (crown ether) increase metal solubility in non-aqueous fluids, broadening the application window. Fluorescent supramolecular polymers have widespread use in fluorescent materials, fluorescence probing, data storage, bio-imaging, drug administration, reproduction, biocatalysis, and cancer treatment. The employment of fluorophores, including organic chromophores and crown ethers, which have high selectivity, sensitivity, and stability constants, opens up new avenues for research. Fluorescent organic compounds are gaining importance in the biological world daily because of their diverse functionality with remarkable structural features and positive properties in the fields of medicine, photochemistry, and spectroscopy.  相似文献   
90.
A photoconversion efficiency of 2.12% was obtained under visible light illumination by nanostructure-sensitized photoelectrochemical cells using Mn/CdS as sensitizer loaded on TiO2 nanotube arrays (NTAs) (Mn/CdS/TiO2). Sensitization of Mn on CdS nanoparticles pre-loaded on TiO2 NTAs was carried out by a two-step electrodeposition method. Compared with unsensitized TiO2 NTAs, the photocurrent had increased from 0.03 to 4.12 for Mn/CdS/TiO2 prepared at 1 min. The effects of deposited Mn on the physical, chemical, and photoelectrochemical properties of the CdS/TiO2 NTAs nanostructure were investigated by using UV–visible diffuse reflectance spectroscopy, X-ray diffractometry, and field-emission scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. The photoelectrochemical analysis was examined in a three-electrode system under a halogen illumination by using the prepared film as the photo-anode.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号