全文获取类型
收费全文 | 2629篇 |
免费 | 96篇 |
国内免费 | 59篇 |
专业分类
化学 | 591篇 |
晶体学 | 1篇 |
力学 | 19篇 |
综合类 | 30篇 |
数学 | 61篇 |
物理学 | 293篇 |
无线电 | 1789篇 |
出版年
2024年 | 4篇 |
2023年 | 38篇 |
2022年 | 28篇 |
2021年 | 34篇 |
2020年 | 55篇 |
2019年 | 47篇 |
2018年 | 44篇 |
2017年 | 73篇 |
2016年 | 94篇 |
2015年 | 116篇 |
2014年 | 181篇 |
2013年 | 182篇 |
2012年 | 192篇 |
2011年 | 186篇 |
2010年 | 161篇 |
2009年 | 178篇 |
2008年 | 188篇 |
2007年 | 186篇 |
2006年 | 150篇 |
2005年 | 132篇 |
2004年 | 96篇 |
2003年 | 81篇 |
2002年 | 66篇 |
2001年 | 44篇 |
2000年 | 30篇 |
1999年 | 38篇 |
1998年 | 26篇 |
1997年 | 27篇 |
1996年 | 31篇 |
1995年 | 16篇 |
1994年 | 11篇 |
1993年 | 7篇 |
1992年 | 10篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 12篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有2784条查询结果,搜索用时 9 毫秒
51.
Dr. Lanjie Lei Prof. Chao Zhao Dr. Xiaofei Zhu Mr. Shuai Yuan Dr. Xing Dong Dr. Yinxiu Zuo Prof. Hong Liu 《Electroanalysis》2022,34(2):415-422
We report on a nonenzymatic electrochemical sensor for wearable glucose monitoring in interstitial fluid. The sensor exhibited acceptable selectivity and reliability for continuous glucose detection for up to 30 days. The sensor tip is coated with polyurethane, and the biocompatibility of the tip is investigated by tissue staining. A fully integrated wearable glucose monitoring system is developed with a wireless connection with a smartphone. The test results are in agreement with reference methods. So, we believe the sensor is promising for the development of a continuous glucose monitoring system and diabetes management. 相似文献
52.
53.
54.
近红外光(NIR)传感器在军事警戒、空间勘探、科研检测、医疗诊断等领域有着极为重要的应用价值。传统的NIR传感材料主要是基于半金属的无机材料,借助窄带隙来吸收低能量的NIR而改变材料自身的电导率,继而实现检测。无机传感材料由于加工繁琐、不具备柔性、成本高昂以及难降解等因素致其进一步发展受到限制。新兴的共轭聚合物材料通过光热转换或者能级可调的光电效应实现对NIR的高灵敏传感,同时能够实现快速响应。该类聚合物材料具有π电子离域的共轭结构,同样具有较窄的带隙,在NIR照射下能够通过自身电导率的改变或光热转换作用将热量传递至其他超热敏材料来实现对光的检测。借助柔性、环境友好、制备简单、便于掺杂、灵敏度高等优势,共轭聚合物材料为新一代NIR传感器的应用与普及开辟了新的前景。 相似文献
55.
A novel thiophene attached anthracene (TA) based fluorescent compound was designed and synthesized. The TA showed a high quantum yield (Qy = 0.34) in regard to fluorescence. We applied this TA compound to detect specific metal compound and found that it could identify CuCl2 from other metals through dramatic fluorescence change at λmax = 460 nm. It showed strong quenching fluorescence property with CuCl2 while with other metal compounds it exhibited strong blue fluorescence emission. UV/Vis absorption spectroscopy clearly demonstrated that the quenching property of TA at λmax = 460 nm was due to overlapping of the fluorescence peak of TA at λmax = 460 nm and the absorption band of CuCl2 (from 190 nm to 525 nm). Binding constant (K′), which was 0.0895 mM?2, indicated a complexation ratio between TA and CuCl2 as 1:2 and this interaction induced quenching property. 相似文献
56.
Bruno Guigas 《Magnetic resonance in chemistry : MRC》2017,55(9):821-827
SpecPad is a new device‐independent software program for the visualization and processing of one‐dimensional and two‐dimensional nuclear magnetic resonance (NMR) time domain (FID) and frequency domain (spectrum) data. It is the result of a project to investigate whether the novel programming language DART, in combination with Html5 Web technology, forms a suitable base to write an NMR data evaluation software which runs on modern computing devices such as Android, iOS, and Windows tablets as well as on Windows, Linux, and Mac OS X desktop PCs and notebooks. Another topic of interest is whether this technique also effectively supports the required sophisticated graphical and computational algorithms. SpecPad is device‐independent because DART's compiled executable code is JavaScript and can, therefore, be run by the browsers of PCs and tablets. Because of Html5 browser cache technology, SpecPad may be operated off‐line. Network access is only required during data import or export, e.g. via a Cloud service, or for software updates. A professional and easy to use graphical user interface consistent across all hardware platforms supports touch screen features on mobile devices for zooming and panning and for NMR‐related interactive operations such as phasing, integration, peak picking, or atom assignment. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
57.
采用N,N′-亚甲基双丙烯酰胺(MBA)为功能单体、钯纳米粒子为掺杂剂、马来松香丙烯酸乙二醇酯为交联剂,在玻碳电极上热聚合具有三甲氧苄啶(TMP)识别性能的钯纳米材料修饰的分子印迹传感膜.采用扫描电镜及红外光谱对合成的钯纳米材料、印迹传感膜的形貌及其结构进行了表征;采用循环伏安法(CV)、交流阻抗法(EIS)对钯纳米粒子掺杂的印迹电极与无掺杂电极的电化学性能进行了研究.结果表明,纳米粒子掺杂的印迹电极与无掺杂电极的表面形貌及电化学性能明显不同.差分脉冲伏安法(DPV)表征结果表明,TMP的浓度在5.0×10-7~4.0 ×10-3 mol/L范围内与脉冲峰电流呈良好的线性关系(R=0.9995),检出限为3.2×10-8 mol/L (S/N=3).此钯纳米粒子掺杂的印迹传感器具有较高的灵敏度.即时电流测定结果表明,新诺明(SMZ)、磺胺嘧啶(SDZ)、葡萄糖 (Glu)、尿素 (Urea)对三甲氧苄啶(TMP)的测定不产生干扰.将此印迹传感器用于实际样品中TMP的检测,加标回收率为96.8%~102.0%. 相似文献
58.
本研究利用阴离子型芘衍生物8-羟基芘-1,3,6-三磺酸三钠盐(HPTS),建立了一种快速、可视化的对硝基苯胺(PNA)荧光检测方法.检测原理主要是基于PNA通过非共价作用而导致的HPTS的荧光淬灭.通过测量加入PNA后HPTS在512 nm处荧光强度的变化,可以实现PNA的荧光检测.本方法的线性范围为10~120μmol/L,检出限(3σ/s)为4.6μmol/L.对本方法的抗干扰性以及方法的实际应用性进行了考察.结果表明,本方法具有低成本、高灵敏度、高选择性、操作简便等优点. 相似文献
59.
利用柠檬酸钠还原氯金酸制得金纳米粒子(AuNPs),基于AuNPs/Nafion与Ru(bpy)32+之间的静电引力,制备了Ru (bpy) 32+/AuNPs/Nafion电化学发光传感器.采用循环伏安法和电化学发光法对该传感器进行了表征,结果表明该传感器具有良好的稳定性和重现性,可实现对已烯雌酚的检测.在pH=7.0的0.1 mol/L磷酸盐缓冲溶液(PBS,含0.05 mol/L三正丙胺)中,当已烯雌酚与修饰电极作用15 min时,电化学发光强度减少值与已烯雌酚浓度的负对数在1.0×10-10~5.0×10-7 mol/L范围内呈良好的线性关系,检出限为6.0 X 10-11 mol/L.对1.0×10-8 mol/L已烯雌酚平行测定11次,相对标准偏差为2.7%.测定已烯雌酚实际样品的加标回收率在98.0%~104.5%之间. 相似文献
60.
Xue-Mei Li Rui-Rui Zhao Yan Yang Xue Wei Lv Yu-Ling Wei Rui Tan Jun-Feng Zhang Ying Zhou 《中国化学快报》2017,28(6):1258-1261
A rhodamine-based sensor (1) has been developed for the detection of chromium ions. Cr3+-induced opening of the rhodamine spirocycle in sensor (1) led to the distinct colorimetric and fluorescence responses. Among all the tested ions, only Cr3+ generated a significant fluorescence enhancement of up to 13-fold, which indicated the high selectivity of 1. Sensor (1) was successfully applied in the in vivo fluorescence imaging of Cr3+ in C. elegans. The results provided solid evidences for the future estimation of Cr3+ in environmental applications and tobacco samples. 相似文献