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71.
On Regularization of a Source Identification Problem in a Parabolic PDE and its Finite Dimensional Analysis 下载免费PDF全文
Subhankar Mondal & M. Thamban Nair 《偏微分方程(英文版)》2021,34(3):240-257
We consider the inverse problem of identifying a general source term, which is a function of both time variable and the spatial variable, in a parabolic PDE from the knowledge of boundary measurements of the solution on some portion of the lateral boundary. We transform this inverse problem into a problem of solving a compact linear operator equation. For the regularization of the operator equation with noisy data, we employ the standard Tikhonov regularization, and its finite dimensional realization is done using a discretization procedure involving the space $L^2(0,\tau;L^2(Ω))$. For illustrating the specification of an a priori source condition, we have explicitly obtained the range space of the adjoint of the operator involved in the operator equation. 相似文献
72.
Bhaskar Das Amit Kar Rudranil Bhowmik Sanmoy Karmakar Satyajit Tripathy Motlalepula G. Matsabisa Pulok Kumar Mukherjee 《Molecules (Basel, Switzerland)》2022,27(4)
A South African traditional formulation, PHELA®, is consumed by the traditional people for severe chest problems with coughing, diarrhea, oral ulcers etc. The present study focused on establishing the anti-infective properties of a safe and standardized poly-herbal formulation through a series of criteria and specifications. 相似文献
73.
Monte Carlo simulation is a very powerful tool for simulation of transient and steady state crystal size distribution (CSD) in a continuous crystallizer under stochastic dispersion effects. In the present work, transient CSD in a continuous crystallizer has been reported when shape factor and growth rate dispersions conform to normal distribution. For the steady state run, the algorithm reported by Sen Gupta and Dutta elsewhere has been used to validate the results obtained in the present work when the steady state is reached. 相似文献
74.
Cobalt‐Embedded Nitrogen‐Rich Carbon Nanotubes Efficiently Catalyze Hydrogen Evolution Reaction at All pH Values 下载免费PDF全文
Dr. Xiaoxin Zou Xiaoxi Huang Dr. Anandarup Goswami Dr. Rafael Silva Dr. Bhaskar R. Sathe Eliška Mikmeková Prof. Tewodros Asefa 《Angewandte Chemie (International ed. in English)》2014,53(17):4372-4376
Despite being technically possible, splitting water to generate hydrogen is still practically unfeasible due mainly to the lack of sustainable and efficient catalysts for the half reactions involved. Herein we report the synthesis of cobalt‐embedded nitrogen‐rich carbon nanotubes (NRCNTs) that 1) can efficiently electrocatalyze the hydrogen evolution reaction (HER) with activities close to that of Pt and 2) function well under acidic, neutral or basic media alike, allowing them to be coupled with the best available oxygen‐evolving catalysts—which also play crucial roles in the overall water‐splitting reaction. The materials are synthesized by a simple, easily scalable synthetic route involving thermal treatment of Co2+‐embedded graphitic carbon nitride derived from inexpensive starting materials (dicyandiamide and CoCl2). The materials’ efficient catalytic activity is mainly attributed to their nitrogen dopants and concomitant structural defects. 相似文献
75.
超导纳米线单光子探测器件(SNSPD)是超导单光子探测系统的核心器件。文中介绍了成功制备的基于5nm厚的NbN超导超薄薄膜的SNSPD器件。器件核心结构为150nm宽的纳米曲折线结构,纳米线条占空比为75%,面积为20μm×20μm。超导纳米线是利用电子束曝光(EBL)技术和反应离子刻蚀(RIE)等工艺技术制备的。所制备的SNSPD样品,在温度3.5K下的临界电流约12.9μA;在1310nm波长光波辐照,12.5μA的偏置电流下,探测效率约0.016%。 相似文献
76.
Subhasis Mallick Subala Mondal Arup Mandal Biplab K. Bera Parnajyoti Karmakar Alak K. Ghosh 《国际化学动力学杂志》2011,43(9):498-506
The kinetics of the interaction of three glycine‐containing dipeptides, namely, glycine‐L‐leucine (Gly‐Leu), glycine‐L‐isoleucine (Gly‐Ile), and glycine‐valine (Gly‐Val) with [Pt(en)(H2O)2](ClO4)2 has been studied spectrophotometrically as a function of [substrate complex], [dipeptides] and temperature at a particular pH(4.0), where the substrate complex exists predominantly as the diaqua species and the dipeptides as a zwitterion. The substitution reaction shows two consecutive steps; the first is the ligand‐assisted anation and the second is the chelation step. The activation parameters for both the steps were evaluated using Eyring's equation. The low ΔH1≠ and large negative value of ΔS1≠ as well as ΔH2≠ and ΔS2≠ indicate an associative mode of activation for both the aqua ligand substitution processes. © 2011 Wiley Periodicals, Inc. Int J Chem Kinet 43: 498–506, 2011 相似文献
77.
Mondal Naba Kumar Das Pradyut Kumar Roy Bijan Kumar Ghosh Barindra Kumar 《Transition Metal Chemistry》1999,24(6):678-682
The reaction of [OsX2(HL)(L)] (1) {X = Cl or Br; HL = PhC(O)C(=NOH)Ph (HL1) or PhC(O)C(=NOH)Me (HL2)] with n-BuONO yields mononuclear [OsX(NO)(L1)2] (2) or binuclear [OsX2(NO)(L2)]22 (3) nitrosyls depending on L. The complexes are also obtained by reacting (1) with NaNO2 plus HCl. Molecular weight determinations are in agreement with mono- and binuclear formulations. The diamagnetic orange-red nitrosyls exhibit (NO) at ca. 1890 cm–1 indicating NO+ character of the bound nitrogen monoxide. In 1H-n.m.r. a single sharp L2 methyl signal is in line with the centrosymmetric geometry (4) of the binuclear nitrosyls. The complexes display both spin-allowed and -forbidden charge transfer transitions in the 1000–200 nm range. Both (2) and (3) are electroactive and reductions characteristic of mono- and binuclear compositions are observable on the negative side of s.c.e. They react smoothly with acetylacetone (acacH) in the presence of K2CO3 yielding K[Os(acamo)(L1)2] (5) and K[Os(acac)(acamo)(L2)] (6) [acamo = deprotonated MeC(O)C(=NOH)C(O)Me] respectively. 相似文献
78.
o-Lithio 2,3-; 3,4-; 3,5-; 2,5- and 2,4-dimethoxy-N-methyl-benzamides upon condensation with propylene oxide give corresponding
dimethoxy-3-methyl-3, 4-dihydroisocoumarins. The method has been used to synthesise (±)-6-methoxy mellein. 3-Methyl-6,7-dimethoxy-3,4-dihydroisocoumarin
has been synthesised by an acid catalysed cyclisation reaction. The dihydroisocoumarins have been dehydrogenated to respective
isocoumarins. 相似文献
79.
Graham LA Fout AR Kuehne KR White JL Mookherji B Marks FM Yap GP Zakharov LN Rheingold AL Rabinovich D 《Dalton transactions (Cambridge, England : 2003)》2005,(1):171-180
The manganese(I) tricarbonyl complexes (Bm(R))Mn(CO)3(R = Me, Bz, But, p-Tol) and (PhBmMe)Mn(CO)3, the first bis(mercaptoimidazolyl)borate derivatives for this metal, have been readily prepared and fully characterized. In particular, the presence of three-center-two-electron Mn...H-B interactions in these species, both in solution and in the solid state, has been investigated using a combination of IR and NMR spectroscopies and, in the case of the methyl-, tert-butyl- and para-tolyl-substituted derivatives, by X-ray crystallography. To complement these synthetic and structural studies, the tris(mercaptoimidazolyl)borate complexes (TmMe)Mn(CO)3(R = Me, Bz, But, p-Tol) and (PhTm(Me))Mn(CO)3, as well as the related pyrazolylbis(mercaptoimidazolyl)borate (pzBmMe)Mn(CO)3, have also been synthesized and characterized by a combination of analytical and spectroscopic techniques. 相似文献
80.
Singh AK Mondal JA Ramakrishna G Ghosh HN Bandyopadhyay T Palit DK 《The journal of physical chemistry. B》2005,109(9):4014-4023
The dynamics of ultrafast photoinduced intermolecular electron transfer (ET) from the excited singlet (S1) state of perylene (Pe) to an electron-accepting cationic surfactant molecule, N-cetylpyridinium chloride (CPC), in aqueous micellar solutions has been investigated using the femtosecond transient absorption spectroscopic technique with temporal resolution of 120 fs. The Pe molecule is localized at or near the micellar surface, where it coexists with the pyridinium moieties (headgroups of the micelle) of the surfactant molecule. Following photoexcitation of Pe, an electron is transferred to the neat and geometrically restricted headgroup of the micelle. Dynamics of the forward ET process as well as the geminate recombination or back ET (BET) process have been followed by monitoring the temporal evolution of the S1 state of Pe and the cation radical of Pe (Pe*+), respectively. The multiexponential forward ET process indicates that the ET dynamics is highly correlated with the spatial distributions of the micellar headgroups around a donor Pe molecule and thus dependent on the donor-acceptor distance. The distance-dependent ET and BET rates have been calculated following the method of Weidemaier and Fayer (J. Chem. Phys. 1995, 102, 3820) to get the best fit parameters for the multiexponetial temporal profiles for the S1 state of Pe as well as Pe*+. Because the acceptor is a constituent of the neat micellar medium, their confinement on the surface of the microheterogeneous medium provides a very large concentration such that, even though the forward transfer rate is 0.06 ps(-1) at the distance of closest approach, the ET process is complete within a 200-ps time domain. If the concepts of distribution of ET distances are utilized, the possible role of material diffusion on the kinetics of forward ET is ruled out. This is an experimental study to show, for the first time, the ultrafast distance-dependent light-induced ET dynamics following both the excited state of the donor and the cation radical formed in an ET process using the transient absorption spectroscopic technique in a self-reactive restrictive environment. 相似文献