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421.
生物传感器是近年来的热点研究方向,其中基于折射率变化的光学传感器在灵敏度方面具有很大优势.本文基于α-MoO3设计了一种集成微流腔的法布里-珀罗谐振腔比色生物传感器.理论分析了BK7/Ag/SiO2作为谐振腔反射面的可行性,并进一步用传输矩阵法分析了所设计的比色生物传感器的透射光谱.当微流腔通过不同浓度的NaCl溶液时,比色生物传感器显示出明显的颜色变化.该比色生物传感器灵敏度最高可达600 nm/RIU,可分辨NaCl溶液9‰的浓度变化.由于α-MoO3具有独特的各向异性的光学性质,该比色传感器可以通过简单的旋转设备实现工作波长的调节以更好地适应人眼的光敏感区.另一方面,调节微流腔的厚度也改变该比色生物传感器的工作波长.该比色生物传感器具有结构简单、易于集成、操作成本低、实时检测等优点,为以后设计可调谐比色传感器提供了一种新的选择. 相似文献
422.
A series of Al 2p, K 2p, O 1s and N 1s core‐level spectra have been used to characterize the interaction between potassium (K) and tris(8‐hydroxyquinoline) aluminium (Alq3) molecules in the K‐doped Alq3 layer. All core‐level spectra were tuned to be very surface sensitive in selecting various photon energies provided by the wide‐range beamline at the National Synchrotron Radiation Research Center, Taiwan. A critical K concentration (x = 2.4) exists in the K‐doped Alq3 layer, below which the K‐doped atoms generate a strained environment near the O and N atoms within 8‐quinolinoline ligands. This creates new O 1s and N 1s components on the lower binding‐energy side. Above the critical K coverage, the K‐doped atoms attach the O atoms in the Al—O—C bonds next to the phenoxide ring and replace Al—O—C bonds by forming K—O—C bonds. An Alq3 molecule is disassembled into Alq2 and Kq by bond cutting and bond formation. The Alq2 molecule can be further dissociated into Alq, or even Al, through subsequent formations of Kq. 相似文献
423.
424.
On the boundedness and periodicity of the solutions of a certain vector differential equation of third-order 总被引:1,自引:0,他引:1
Cemil Tune 《应用数学和力学(英文版)》1999,20(2):163-170
IntroductionWeshallbeconcernedherewiththird-ordersystemofnon-lineardifferentialequationsoftheformX F(X,X)X Ba H(X)=P(t,X,X,X),(l)whereX6R",R"denotestherealn-dimensionalEuclldeanspaceRxRx'xR(nfactors),R=(--ac,ac),Fisannxn-matrixfunction,Bisarealnxn-constantsymmetricmatrix,H:R"~R"1andp:RxR"xR"xR"~R".ThedotsindicatCdifferentiationwithrespeCttot.ThefunctionsF,HandParecontinuousforallvaluesoftheirrespeCtivearguments.Moreover,theexistenceandtheuniquenessofthesolutionsof(l)willbeassu… 相似文献
425.
Acta Mechanica Sinica - A novel identification method of aerodynamic models using a physics neural network, named the attitude dynamics network, which incorporates the attitude dynamics of an... 相似文献
426.
Yu Liu Bang‐Tun Zhao Heng‐Yi Zhang Hong‐Fang Ju Lang‐Xing Chen Xi‐Wen He 《Helvetica chimica acta》2001,84(7):1969-1975
A series of novel double‐armed p‐(tert‐butyl)calix[4]arenes, carrying benzoylamido, 4‐nitrobenzoylamido, isonicotinamido, α‐naphthamido, acetamido, propionamido, or butyramido groups (see 2 – 8 , resp.) were synthesized in 80 – 86% yield by the reaction of the lower‐rim 1,3‐bis(aminoethoxy)‐substituted calix[4]arenediol 1 with the corresponding acylating agents. Their structures were established by elemental analysis, mass, IR, UV, and 1H‐NMR spectroscopy. Ion‐selective electrodes (ISEs) for Pb2+, carrying 2 – 8 in a PVC membrane as neutral ionophore, were prepared, and their selectivity coefficients for Pb2+ (K) were determined against other heavy‐metal ions, alkali and alkaline earth metal ions, and ammonium ions by means of the separate‐solution method. The results obtained indicated that the electrodes based on the calix[4]arene‐derived amides 2 – 8 as the neutral ionophores were all Pb2+ selective and exhibited almost theoretical Nernstian slopes, except for 3 and 4 . Typically, the Pb2+‐selective electrode based on 6 – 8 exhibited almost Nernstian slopes for Pb2+ over a relatively wide concentration range and had a fast response time as well as a long lifetime, although the silver ion interfered strongly. These ISEs based on 6 – 8 showed a relatively good Pb2+ selectivity against most of the interfering cations examined, except for Ag+. The effect of the side‐arm functions of calix[4]arene derivatives 2 – 8 on the Nernstian slopes and on the selectivity coefficients for Pb2+ obtained with the Pb2+ ISEs based on 2 – 8 is discussed. 相似文献
427.
A robust method for solving the chemical non-equilibrium Navier–Stokes equations, including all of the species conservation and energy production equations, is developed. The algorithm is embodied in a fully coupled, implicit, large block structure. Van Leer flux splitting for inviscid terms and central differencing for viscous terms in the explicit operators are applied in the numerical algorithm. The fully-coupled system is solved implicitly and the bi-conjugate gradient stable (Bi-CGSTAB) method with a preconditioner of incomplete lower–upper (LU)-factorization (ILU) is used for solving large block structure and diagonal dominate matrix equations. The computations are performed for the hypersonic inflow over blunt bodies including half cylinder, double ellipse and blunt nose. The adaptive grid constructed by moving grid method is employed to capture the shock location. Computational results in the present study are compared with other calculated data and exhibit good agreement. Convergence histories of the mean flow variables and species equations demonstrate that the fast convergent rate can be achieved by the preconditioned Bi-CGSTAB method. © 1998 John Wiley & Sons, Ltd. 相似文献
428.
Ng Wei Wuen Thiam Hui San Pang Yean Ling Lim Yun Seng Wong Jianhui 《Journal of Solid State Electrochemistry》2023,27(6):1477-1492
Journal of Solid State Electrochemistry - Getting the direct methanol fuel cell (DMFC) closer to mass production requires the creation of a high-performance and long-lasting proton exchange... 相似文献
429.
Qixia Bai Yu-Ming Guan Tun Wu Ying Liu Zirui Zhai Qingwu Long Zhiyuan Jiang Peiyang Su Ting-Zheng Xie Pingshan Wang Zhe Zhang 《Angewandte Chemie (International ed. in English)》2023,62(39):e202309027
The precise control over hierarchical self-assembly of superstructures relying on the elaboration of multiple noncovalent interactions between basic building blocks is both elusive and highly desirable. We herein report a terpyridine-based metallo-cage T with a tetrahedral motif and utilized it as an efficient building block for the controlled hierarchical self-assembly of superstructures in response to different halide ions. Initially, the hierarchical superstructure of metallo-cage T adopted a hexagonal close-packed structure. By adding Cl−/Br− or I−, drastically different hierarchical superstructures with highly-tight hexagonal packing or graphite-like packing arrangements, respectively, have been achieved. These unusual halide-ion-triggered hierarchical structural changes resulted in quite distinct intermolecular channels, which provided new insights into the mechanism of three-dimensional supramolecular aggregation and crystal growth based on macromolecular construction. In addition, the chiral induction of the metallo-cage T can be realized with the addition of chiral anions, which stereoselectively generated either PPPP- or MMMM-type enantiomers. 相似文献