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141.
引入了拓扑覆盖的概念,并结合最小描述元对有限论域上的拓扑覆盖加于研究,得出了拓扑覆盖的最简覆盖和基与最小描述元之间的关系.介绍了在基于有限论域U上的覆盖,构造U上的一个拓扑的方法.并且在最小描述元的基础上将划分下的粗糙隶属函数推广至一般覆盖下的粗糙隶属函数,而后介绍了其相关运用.  相似文献   
142.
Multilayers of myoglobin (Mb) with ionic liquid 1‐ethyl‐3‐methylimidazolium tetrafluoroborate ([EMIM]BF4) was assembled on carbon ionic liquid electrode (CILE) based on the electrostatic attraction between the negatively charged Mb and the positively charged imidazolium ion of IL. The CILE was fabricated with 1‐ethyl‐3‐methylimidazolium ethylsulfate ([EMIM]EtOSO3) as the modifier, which exhibited imidazolium ion on the electrode surface. Then Mb molecules were assembled on the surface of CILE step‐by‐step to get a {IL/Mb}n multilayer film modified electrode. UV‐Vis adsorption and FT‐IR spectra indicated that Mb remained its native structure in the IL matrix. In deaerated phosphate buffer solution (pH 7.0) a pair of well‐defined quasi‐reversible redox peaks appeared with the apparent formal potential (E0′) as ‐0.212 V (vs. SCE), which was the characteristic of Mb heme Fe(III)/Fe(II) redox couples. The results indicated that the direct electron transfer of Mb was realized on the modified electrode. The {IL/Mb}n/CILE displayed excellent electrocatalytic ability to the trichloroacetic acid reduction in the concentration range from 2.0 to 22.0 mmol/L with the detection limit of 0.6 mmol/L (3σ). The proposed method provides a new platform to fabricate the third generation biosensor based on the self‐assembly of redox protein with ILs.  相似文献   
143.
The mechanism and conformational changes of farrerol binding to bovine serum albumin (BSA) were studied by spectroscopic methods including fluorescence quenching technique, UV–vis absorption, circular dichroism (CD) spectroscopy and Fourier transform infrared (FT-IR) spectroscopy under simulative physiological conditions. The results of fluorescence titration revealed that farrerol could strongly quench the intrinsic fluorescence of BSA through a static quenching procedure. The thermodynamic parameters enthalpy change and entropy change for the binding were calculated to be −29.92 kJ mol−1 and 5.06 J mol−1 K−1 according to the van’t Hoff equation, which suggested that the both hydrophobic interactions and hydrogen bonds play major role in the binding of farrerol to BSA. The binding distance r deduced from the efficiency of energy transfer was 3.11 nm for farrerol–BSA system. The displacement experiments of site markers and the results of fluorescence anisotropy showed that warfarin and farrerol shared a common binding site I corresponding to the subdomain IIA of BSA. Furthermore, the studies of synchronous fluorescence, CD and FT-IR spectroscopy showed that the binding of farrerol to BSA induced conformational changes in BSA.  相似文献   
144.
Polythieno[3,2-b]thiophene (PTT) was electrosynthesized by facile anodic oxidation of thieno[3,2-b]thiophene (TT) in three systems: boron trifluoride diethyl etherate (BFEE), acetonitrile (ACN), and dichloromethane solutions. The onset oxidation potential of TT in BFEE was determined to be 0.62?V vs. Ag/AgCl, which was much lower than those in ACN and dichloromethane solutions. PTT films exhibited excellent electrochemical property, high thermal stability, good redox activity, and stability. Free-standing PTT films with good mechanical property can be obtained from BFEE solution, whose structure and morphology were characterized by FT-IR, UV?Cvisible spectra, and scanning electron microscopy. With an electrical conductivity of 1.5?S?cm?1 and a Seebeck coefficient of 85???V?K?1 at 306?K, the as-prepared free-standing PTT films showed a certain thermoelectric property. The dimensionless figure-of-merit of PTT films was estimated to be 2.3?×?10?3 at 306?K, which was much higher than those of some organic thermoelectric materials reported previously. All these results indicated that PTT films may have potential applications in the thermoelectric field.  相似文献   
145.
介绍和研究了实q-一致光滑Banach空间中一类新的具(A,η)一增生算子的广义混合拟一似变分包含组,利用(A,η)一增生算子的预解算子技巧,证明了解的存在性及由新的P步迭代算法所生成序列的收敛性.  相似文献   
146.
为提升结构整体性能和抗震性能,基于结构构件应变能对材料弹性模量的敏感性及其失效后结构的应变能变化量,建立了结构易损性与冗余度评价指标,以衡量在地震作用下构件发生破坏的容易程度及其失效后对结构整体性能的影响.考虑地震作用下结构构件冗余度及易损性差异,通过加强低冗余-高易损构件,同时削弱高冗余-低易损构件,合理调整各类构件截面面积.结果 表明,构件的冗余度和易损性可以准确反映地震作用下结构构件的重要性及发生破坏的容易程度,考虑构件冗余度及易损性差异,调整结构构件面积,可有效提升结构的整体性能及抗震性能.  相似文献   
147.
In this paper, we investigate some nonlocal diffusion problems with free boundaries. We first give the existence and uniqueness of local solution by the ODE basic theory and the contraction mapping principle. Then we provide a complete classification for the global existence and finite time blow-up of solutions. Moreover, estimates of blow-up rate and blow-up time are also obtained for the blow-up solution.  相似文献   
148.
采用熔融共混技术,将聚磷酸铵(APP)和氢氧化铝(ATH)引入到聚氨酯弹性体(TPU)中,制备了一系列热塑性聚氨酯/聚磷酸铵/氢氧化铝(TPU/APP/ATH)复合材料。采用傅里叶红外光谱(FTIR)、X-射线光电子能谱(XPS)、扫描电镜(SEM)、激光拉曼光谱研究了TPU和阻燃TPU(FR-TPU)复合材料燃烧后炭渣的微观形貌、表面结构、元素组成、键合状态和石墨化程度,结合阻燃性能测试,揭示APP和ATH的协同阻燃机制。SEM分析表明相较于APP与ATH单独使用,TPU/APP/ATH炭层的空洞结构更少,炭渣的致密性更高。XPS分析表明FR-TPU的炭渣中C元素含量相比于纯TPU有所降低,O元素的含量有所上升,其中TPU/APP10/ATH10的C元素含量从88.2%降至69.24%,O元素的含量从8.07%升至17.78%,P和Al元素含量相较于单独添加分别从11.74%和16.36%下降至3.91%和3.31%。在此基础上,通过对C元素的分峰拟合发现TPU炭渣中C—C/C—H,C—O/C—N和CO/CN含量分别为61.05%,35.65%和3.30%;TPU/APP10/ATH10炭渣中三种结构含量分别为45.38%,45.00%和9.63%,说明ATH和APP复配使用有利于C元素形成酯、醚、羰基、羧酸(盐)、酯基等结构。通过对O元素的分峰拟合发现,TPU炭渣中O2/H2O,—O—,O三种结构含量分别为28.75%,44.36%和26.89%;TPU/APP10/ATH10炭渣中O2/H2O,—O—,O三种结构含量分别为44.33%,32.78%和22.89%,说明APP和ATH的加入有利于炭渣中O元素形成O2/H2O结构。通过对N元素的分峰拟合发现,TPU炭渣中—NH—,N结构的N元素含量分别为40.93%和59.07%;TPU/APP10/ATH10中—NH—,N结构的N元素含量分别47.17%和52.83%,说明ATH与APP复配使用促进了—NH—结构的形成。拉曼测试表明,相比于单独使用,APP和ATH复配使用,炭层的石墨化程度更好,致密性更高。以上分析结合阻燃测试可以得出TPU/APP/ATH复合材料阻燃机制:ATH受热分解生成氧化铝,吸收热量并释放大量水蒸气,有效促进APP降解,生成不燃性的氨气和聚磷酸,氨气和水蒸气稀释可燃性气体的浓度。随着温度继续升高,氧化铝可继续与聚磷酸反应生成偏磷酸铝[Al(PO3)3],同步催化聚氨酯基体成炭,形成高度石墨化炭层,石墨化炭层与偏磷酸铝一起覆盖在基体表面,有效抑制燃烧区域物质以及能量的输运,从而达到阻燃目的。  相似文献   
149.
能量色散X射线荧光(EDXRF)光谱分析待测元素的信息主要反映在能谱的特征峰峰位以及特征峰净峰面积中。对于特征峰的准确检测是EDXRF光谱分析的关键。特征X射线之间的能量在低原子序数元素中相差很小,在实际测量过程中由其他一些因素干扰会导致EDXRF光谱中特征峰产生严重重叠,以EDXRF光谱中低序列元素的重叠峰作为研究对象,提出一种四次导数结合三样条小波变换处理低序列元素重叠峰的新方法。通过数学模型模拟重叠峰检测了该方法的可行性,并仿真了实测X荧光光谱数据进行检测得到良好的效果,通过使用了CIT-3000SY X 荧光元素录井仪实测T铅黄铜数据和混合轻元素数据荧光光谱作为验证。首先,介绍导数法以及三样条小波法分解重叠的原理。导数法阶数越高信号越畸形但可以有效提高重峰分离度,而三样条小波变换对低分离度重峰处理较为无力但能有效的保持峰型。通过Tsallis峰信号模拟重叠峰,模拟出3个峰信号,第1个峰和第2个峰的分离度R=0.33,第2个峰和第3个峰的分离度R=0.67,导数处理后信号任仍具有一部分重叠,但是导数处理后不仅保留了信号的峰位值,且出现了分离度变大的现象,而三样条小波对低分离度重叠峰的分解较为无力,但是对于分离度较大的重叠峰具有较好的效果,信号通过四次导增加分离度再进行三样条小波变换,通过调节样条小波分解层次的次数,然后对分解出的高频信号采取适当的系数进行放大,最后进行信号重构。实验实现了对模拟信号的分解。验证了此方法针对重叠峰分解具有可行性。实验采用分解4层的三样条小波变换以及放大6倍的高频信号。然后,处理仿真K元素的重叠光谱,实现了重叠峰的分解,通过仿真实验表明新方法能准确的识别峰位,结果表明只有1%之内的误差,证明了新方法对X荧光光谱重叠峰分解的适用性。最后用此方法对CIT-3000SY X荧光元素录井仪实测T铅黄铜元素数据以及混合轻元素数据X荧光光谱进行处理,实现了对重叠峰的分解,且分解后的峰位误差控制在1%之内,具有较高的准确率。实验结果证明:四次导数结合三样条小波变换能有效分离重叠峰,并且在处理X荧光光谱的重叠峰分解上具有实用性。  相似文献   
150.
The flow-shop scheduling problem with the makespan criterion is a certain strongly NP-hard case from the domain of OR. This problem, having simple formulation contrasting with its troublesome, complex and time-consuming solution methods, is ideal for testing the quality of advanced combinatorial optimization algorithms. Although many excellent approximate algorithms for the flow-shop problem have been provided, up till now, in the literature, some theoretical and experimental problems associated with an algorithm’s activity still remain unexamined. In this paper, we provide a new view on the solution space and the search process. Relying upon it, we are proposing the new approximate algorithm, which applies some properties of neighborhoods, refers to the big valley phenomenon, uses some elements of the scatter search as well as the path relinking technique. This algorithm shows up to now unprecedented accuracy, obtainable within a short time on a PC, which has been confirmed in a wide variety of computer tests. Good properties of the algorithm remain scalable if the size of instances increases.  相似文献   
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