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61.
Integration of multiple objectives to evaluate the alternative operating rules for urban water supply reservoir systems can be effectively accomplished by multi-criteria decision aid techniques, where preference elicitation and modelling plays an important role. This paper describes a preference elicitation and modelling procedure involving the multi-criteria outranking method PROMETHEE in evaluating these alternative operating rules. The Melbourne water supply system was considered as the case study. Eight performance measures (PMs) were identified under four main objectives to evaluate the system performance under alternative operating rules. Three major hypothetical stakeholder groups namely, resource managers, water users, and environmental interest groups were considered in decision-making. An interviewer-assisted questionnaire survey was used to derive the preference functions and weights of the PMs. The evaluation of alternative operating rules is not covered in this paper, rather an approach to elicit and model stakeholder preferences in decision-making is described. 相似文献
62.
D. D. Coon A. G. U. Perera 《International Journal of Infrared and Millimeter Waves》1987,8(9):1037-1052
A new approach to focal plane processing based on silicon injection mode devices is suggested. These devices provide a natural basis for parallel asynchronous focal plane image preprocessing. The simplicity and novel properties of the devices would permit an independent analog processing channel to be dedicated to every pixel. A laminar architecture built from arrays of the devices would form a two-dimensional (2-D) array processor with a 2-D array of inputs located directly behind the focal plane detector array. A 2-D image data stream would propagate in neuronlike asynchronous pulse coded form through the laminar processor. No multiplexing, digitization or serial processing would occur in the preprocessing stage. High performance is expected because approximately linear pulse coding has already been observed for input currents ranging over six orders of magnitude down to one picoampere with noise referred to input of about 10 femtoamperes. Very low power requirements suggest utility in space and in conjunction with very large arrays. Multispectral processing is possible because of compatibility with the cryogenic environment of high performance infrared detectors. 相似文献
63.
Cronin-Hennessey D Kwon Y Lyon AL Thorndike EH Jessop CP Mariske H Perl ML Savinov V Ugolini D Zhou X Coan TE Fadeyez V Maravin Y Narsky I Stroynowski R Ye J Wlodek T Artuso M Ayad R Boulahouache C Bukin K Dambasuren E Karamnov S Kopp S Majumder G Moneti GC Mountain R Schuh S Skwarnicki T Stone S Viehauser G Wang JC Wolf A Wu J Csorna SE Danko I McLean KW Márka S Xu Z Godang R Kinoshita K Lai IC Schrenk S Bonvicini G Cinabro D Perera LP Zhou GJ Eigen G Lipeles E Sharma V 《Physical review letters》2000,85(3):515-519
We have studied charmless hadronic decays of B mesons into two-body final states with kaons and pions and observe three new processes with the following branching fractions: beta(B-->pi(+)pi(-)) = (4.3(+1. 6)(-1.4)+/-0.5)x10(-6), beta(B-->K(0)pi(0)) = (14.6(+5.9+2.4)(-5.1-3. 3))x10(-6), and beta(B-->K(+)/-pi(0)) = (11.6(+3.0+1.4)(-2.7-1.3))x10(-6). We also update our previous measurements for the decays B-->K(+)/-pi(-/+) and B+/--->K(0)pi(+/-). 相似文献
64.
Akerib DS Alvaro-Dean J Armel-Funkhouser MS Attisha MJ Baudis L Bauer DA Beaty J Brink PL Bunker R Burke SP Cabrera B Caldwell DO Callahan D Castle JP Chang CL Choate R Crisler MB Cushman P Dixon R Dragowsky MR Driscoll DD Duong L Emes J Ferril R Filippini J Gaitskell RJ Haldeman M Hale D Holmgren D Huber ME Johnson B Johnson W Kamat S Kozlovsky M Kula L Kyre S Lambin B Lu A Mahapatra R Manalaysay AG Mandic V May J McDonald R Merkel B Meunier P Mirabolfathi N Morrison S Nelson H Nelson R 《Physical review letters》2004,93(21):211301
We report the first results from a search for weakly interacting massive particles (WIMPs) in the Cryogenic Dark Matter Search experiment at the Soudan Underground Laboratory. Four Ge and two Si detectors were operated for 52.6 live days, providing 19.4 kg d of Ge net exposure after cuts for recoil energies between 10 and 100 keV. A blind analysis was performed using only calibration data to define the energy threshold and selection criteria for nuclear-recoil candidates. Using the standard dark-matter halo and nuclear-physics WIMP model, these data set the world's lowest exclusion limits on the coherent WIMP-nucleon scalar cross section for all WIMP masses above 15 GeV/c2, ruling out a significant range of neutralino supersymmetric models. The minimum of this limit curve at the 90% C.L. is 4 x 10(-43) cm2 at a WIMP mass of 60 GeV/c2. 相似文献
65.
Four phenolic steroids were titrated coulometrically with bromine in a methanol—water solvent containing hydrochloric acid and sodium bromide. End-point detection was achieved with a twin electrode thin-layer cell placed in a flow loop connected to the titration vessel. Linear-segmented biamperometric titration curves were recorded. Concentrations of 17-β-estradiol were determined in the range from 442 ppb to 8.84 ppm with relative inaccuracies of -1.3% and +2.2%, respectively. Part-per-million solutions of estrone and estriol were titrated with good accuracy and precision. Somewhat poorer precision and accuracy was found for the determination of 17-α-ethynyl estradiol. 相似文献
66.
A sandwich-type thin-layer cell has been applied to hydrodynamic biamperometric end-point detection in coulometric titrations. The detector cell, constructed from two pieces of teflon, has platinum indicator electrodes and is placed in a flow loop attached to the coulometric titration cell. The thin-layer cavity has a volume of 6.5 μl and a thickness of 51μm, which are obtained using teflon tape as a spacer. A peristaltic pump maintains a continual flow through the loop. The titration cell is a closed vessel completely filled with the solution to be titrated. Operational amplifier circuits control the potential difference applied across the two thin-layer electrodes, and to measure the current developed in the thin-layer cell. Noise arising from the pulsed nature of the flow is reduced by a factor of 25 by using an electronic filter. The titration of arsenic(III) with electrogenerated bromine was used to study the performance of the system. Concentrations from 24 ppb to 1.6 ppm can be determined with relative inaccuracies of +4 and +0.1%, respectively. 相似文献
67.
Standard calibration methods used to determine trace analytes usually yield significant deviations from the actual analyte value in the presence of interferents in the assay media. These deviations become of particular concern when the concentration of the analyte is low, and when the results are used to draw mechanistic or kinetic conclusions, for instance in enzyme structure-function studies. In these circumstances, the H-point standard addition method (HPSAM) provides superior precision and accuracy. This method is developed here for the case of the spectrophotometric Griess assay used to determine nitrite in various enzymology investigations, such as nitrite determination in studies of nitrite reductases (NiR), or when determining nitrite as a breakdown product of nitric oxide synthesized by NOS enzymes. The results obtained by HPSAM are contrasted with those of the traditional calibration method.Electronic Supplementary Material Supplementary material is available for this article at 相似文献
68.
K. Prasanna U. Perera Khalil A. Abboud Mariusz Krawiec Don VanDerveer Dennis W. Smith Jr. 《Journal of chemical crystallography》2006,36(6):399-406
A representative compound of bis-ortho-diynyl arene (BODA), with a general formula [(m,p)R2–Ph]2
–X, where R: –C≡C–Ph and X: >C(CF3)2 has been structurally characterized. The compound is being investigated as a monomer for high-performance polyarylene networks and glassy carbon precursors. The bis(trifluoromethyl) derivative crystallizes in two concomitant polymorphic forms. The two polymorphs form a monotropic system with melting points of 436 and 463 K. The metastable form yields monoclinic crystals (P21/n, Z=4). a=12.677(3) ?, b=11.677(2) ?, c=24.026(5) ?, β=93.79(3)°. The thermodynamically stable form is monoclinic as well (P21/c, Z=8), a=10.7983(6) ?, b=30.628(2) ?, c=21.648(1) ?, β=94.737(1)° with small voids indicating less efficient packing. The two polymorphs contain different conformers of the rotationally flexible molecule. 相似文献
69.
70.
A. G. U. Perera 《Opto-Electronics Review》2006,14(2):99-108
The work describes multiband photon detectors based on semiconductor micro-and nano-structures. The devices considered include
quantum dot, homojunction, and heterojunction structures. In the quantum dot structures, transitions are from one state to
another, while free carrier absorption and internal photoemission play the dominant role in homo or heterojunction detectors.
Quantum dots-in-a-well (DWELL) detectors can tailor the response wavelength by varying the size of the well. A tunnelling
quantum dot infrared photodetector (T-QDIP) could operate at room temperature by blocking the dark current except in the case
of resonance. Photoexcited carriers are selectively collected from InGaAs quantum dots by resonant tunnelling, while the dark
current is blocked by AlGaAs/InGaAs tunnelling barriers placed in the structure. A two-colour infrared detector with photoresponse
peaks at ∼6 and ∼17 μm at room temperature will be discussed. A homojunction or heterojunction interfacial workfunction internal
photoemission (HIWIP or HEIWIP) infrared detector, formed by a doped emitter layer, and an intrinsic layer acting as the barrier
followed by another highly doped contact layer, can detect near infrared (NIR) photons due to interband transitions and mid/far
infrared (MIR/FIR) radiation due to intraband transitions. The threshold wavelength of the interband response depends on the
band gap of the barrier material, and the MIR/FIR response due to intraband transitions can be tailored by adjusting the band
offset between the emitter and the barrier. GaAs/AlGaAs will provide NIR and MIR/FIR dual band response, and with GaN/AlGaN
structures the detection capability can be extended into the ultraviolet region. These detectors are useful in numerous applications
such as environmental monitoring, medical diagnosis, battlefield-imaging, space astronomy applications, mine detection, and
remote-sensing.
The paper presented there appears in Infrared Photoelectronics, edited by Antoni Rogalski, Eustace L. Dereniak, Fiodor F. Sizov, Proc. SPIE Vol. 5957, 59570W (2005). 相似文献