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   120篇
  免费   13篇
  国内免费   28篇
化学   78篇
晶体学   2篇
力学   8篇
综合类   2篇
数学   14篇
物理学   57篇
  2024年   1篇
  2023年   9篇
  2022年   10篇
  2021年   8篇
  2020年   8篇
  2019年   3篇
  2017年   10篇
  2016年   9篇
  2015年   6篇
  2014年   9篇
  2013年   10篇
  2012年   13篇
  2011年   5篇
  2010年   4篇
  2009年   10篇
  2008年   6篇
  2007年   2篇
  2006年   9篇
  2005年   5篇
  2004年   1篇
  2003年   3篇
  2002年   2篇
  2001年   1篇
  2000年   1篇
  1999年   2篇
  1998年   1篇
  1997年   1篇
  1996年   4篇
  1995年   1篇
  1993年   1篇
  1991年   2篇
  1990年   4篇
排序方式: 共有161条查询结果,搜索用时 0 毫秒
1.
赵慧洁  贾国瑞 《光学学报》2008,28(3):583-586
时空联合调制型干涉成像光谱仪获取的像面干涉图是带有干涉条纹的二维空间图像,具有对姿态变化敏感的特点.根据该类仪器的成像过程,在竖直摄影时,相邻两帧像面干涉图之间的像移量为一列像元;偏离竖直摄影时,由于像面干涉图的几何变形或旋转,会引入非正常像移.利用共线方程导出了这一非正常像移量的表达式.利用仿真计算说明:这一非正常像移会在像面干涉图序列中不断积累,导致提取出的物体干涉信息失真.在竖直摄影而平台指向精度较低、倾斜摄影、探测器阵列的安装方向精度较低或者航空成像且存在偏流角时,必须对像面干涉图进行有效校正,才能保证最终反演出的物体光谱的真实性.  相似文献   
2.
Postoperative fatigue syndrome (POFS) is a common clinical complication following almost every major abdominal surgery. There is not a full explanation of the etiology of POFS, especially its central mechanism. Carthamus tinctorius L. is a classic traditional Chinese medicine (TCM) which could exert ananti‐fatigue effect on POFS. However, its mechanism is still lacking. Here, ultra‐high performance liquid chromatography coupled with a quadrupole time‐of‐flight mass spectrometry (UHPLC‐Q‐TOFMS) based metabonomic approach was used to characterize hippocampal metabolic fluctuations of POFS in a rat model induced by partial hepatectomy, and to evaluate the anti‐fatigue effect of C. tinctorius L. extract (CTLE). With partial least‐squares discriminant analysis for classification and selection of biomarkers, 15 hippocampal metabolites related to POFS were identified, primarily involving alanine, aspartate and glutamate metabolism, valine, leucine and isoleucine degradation, purine metabolism, phenylalanine metabolism, tryptophan metabolism, phospholipid metabolism and fatty acid metabolism. With these altered metabolic pathways as possible drug targets, we systematically analyzed the protective effect of CTLE, which showed that CTLE could provide an anti‐fatigue effect on POFS through partially regulating the perturbed metabolic pathways. This study indicated that UHPLC‐Q‐TOFMS‐based metabolomics provided a powerful tool to reveal hippocampal metabolic fluctuations of POFS and study the mechanism of TCM. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
3.
4.
上转换发光免疫试纸条扫描检测系统研究   总被引:3,自引:0,他引:3  
研制了一种以上转换发光材料作为标记物的扫描检测系统,有别于传统的测量方法,可做出定量和多重分析.扫描检测系统以扫描方式逐点测量经生物反应而结合上去的UCP颗粒的含量,记录整个免疫试纸条的信息,计算出被测样品中特定生物分子的浓度.实验结果表明,该系统对兔抗鼠疫免疫球蛋白(IgG)标准样品的检测灵敏度达到百ng/mL量级,且具有变异系数小于6%的重复性,符合生物免疫测定的要求.  相似文献   
5.
光纤生物传感器用于核酸的特异性检测   总被引:15,自引:2,他引:15  
为了利用光纤传感器实现对细菌核酸分子的特异性和相对快速检测,我们使用直径1mm的石英光纤和635nm激光二极管,利用倏逝波原理制作了光纤生物传感器。光纤经过处理后产生醛基化基团,然后与核酸分子进行共价结合。通过3个实验来验证传感器的特异性和灵敏度。蒌光素溶液直接检测,使用互补模式寡核苷酸分子(25mer)进行核酸杂交模式实验和设计嗜肺军团菌一段特异性探针一 光标记嗜肺军团菌染色体DNA杂交。结果表明:光纤检测荧光素的灵敏度可达0.01mmol/L,而生物芯片扫描仪最低可检测到1nmol/L的荧光素;模式寡 核苷酸杂交表明:光纤传感器可以特异地检出目的核酸分子,灵敏度可达纳克级水平;染色体杂交结果显示在正常检测浓度下,光纤检测军团菌之信噪比达到了6:1,同时具有较好的特异性。检测时间约需要3-4h。我们构建的光纤生物传感器可以用于核酸分子的特异性检测,并且具有较好的灵敏度,对光纤表面修饰、样品处理和杂交过程的优化可望使之应用于实际标本的检测。  相似文献   
6.
建立了测定硝苯地平中基因毒性杂质2、6和12的超高效液相色谱-静电场轨道阱高分辨质谱法(UHPLC-Orbitrap HRMS).样品以甲醇为溶剂,提取后直接进样分析.采用ACE EXCELTM 3 C18-AR色谱柱(150 mm×4.6 mm,3μm)分离,流动相为甲醇-0.1%甲酸水(65:35,v/v),等度洗...  相似文献   
7.
A method for automatically identifying the order of fringe pattern traces is presented. It uses the simplified Otsu algorithm for obtaining the threshold, the angular scan in the range of 45~ for searching the trace positions, and the zone search technique for identifying different traces. Experimental results show that the proposed method may reliably obtain the order of fringe pattern traces orientating from almost 45° to 90°.  相似文献   
8.
9.
Nucleus-targeted therapy holds great promise in cancer treatment; however, a lack of effective nucleus-specific delivery significantly limits its application potential. Here, we report a nucleus-targeted synergistic chemo-photodynamic therapy based on the self-assembly of chlorin e6 (Ce6) and doxorubicin (DOX) tuned by clickable dibenzocyclooctyne (DIBO) functionalized lysine (D-K) and subsequent reaction with crosslinkers. The assembled nanodrugs with high loading efficiency and long-term stability show enhanced cellular uptake and accumulation in the nucleus, resulting in greatly improved in vitro and in vivo chemo-photodynamic efficacy. Notably, D-K can promote the rapid self-assembly of Ce6 and DOX in aqueous solution, avoiding the introduction of organic solvents or tedious preparations. In addition, the introduction of the DIBO group can effectively expand the types of self-assembly material and enhance the self-assembly behaviour through a copper-free click reaction. Therefore, we present an effective nucleus-targeted combination drug delivery strategy, which has great potential in the treatment of many diseases.

A highly efficient nucleus-targeted multi-drug delivery nanoplatform based on clickable amino acid tuned self-assembly of chlorin e6 and doxorubicin has been prepared for enhanced photodynamic therapy and chemotherapy.  相似文献   
10.
A method of clarifying bioaerosol particles is proposed based on T-matrix. Size and shape characterizations are simultaneously acquired for individual bioaerosol particles by analyzing the spatial distribution of scattered light. The particle size can be determined according to the scattering intensity,while shape information can be obtained through asymmetry factor(AF) . The azimuthal distribution of the scattered light for spherical particles is symmetrical,whereas it is asymmetrical for non-spherical ones,and the asymmetry becomes intense with increasing asphericity. The calculated results denote that the 5 –10 scattering angle is an effective range to classify the bioaerosol particles that we are concerned of. The method is very useful in real-time environmental monitoring of particle sizes and shapes.  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