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981.
本文介绍了降秩因子(RAFA)方法,它是从一个多组分混合物中直接定量计算其中某一组分,而不必知道其他组分的物种及含量的一种定量分析的数学方法。它适用于双线性的数据。本实验首先将荧光分光光度计与外接计算机相连,以获得样品的激发-发射矩阵(EEM),再用RAFA方法对蒽,萘,菲,芘,芴,Qu六种标样的一至五组分的混合物进行定量分析,获得满意的结果。 相似文献
982.
Akikazu Matsumoto Sachiyo Umehara Hiroyuki Watanabe Takayuki Otsu 《Journal of Polymer Science.Polymer Physics》1993,31(5):527-535
Poly(N-n-butylitaconimide) was prepared by radical polymerization in benzene and in bulk at 60°C and was subsequently fractionated at 30°C with benzene and methanol as solvent and nonsolvent, respectively. Relationships between molecular weight and intrinsic viscosity (Mark-Houwink-Sakurada equations) in tetrahydrofuran, benzene, and toluene at 30°C are established. From the Burchard-Stockmayer-Fixman plot, the characteristic ratio of this polymer is determined, and local chain conformation is discussed in relation to the termination process in radical polymerization. © 1993 John Wiley & Sons, Inc. 相似文献
983.
V. A. Petrosyan L. V. Adaevskaya O. S. Chizhov A. Yu. Romanovich 《Russian Chemical Bulletin》1993,42(1):129-131
Direct electrochemical reduction of specially synthesized 2-[(diethoxyphosphorylacetoxy] benzaldehyde on a platinum electrode in an aprotic medium is accompanied by ester bond cleavage, and not formation of coumarin via the phosphonate-anion followed by intramolecular Horner cyclization. This could be realized, as a matter of principle, in the presence of an ionol anion (2,6-di-tert-butyl-4-methylphenoxide), electrochemically generatedin situ.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 144–146, January, 1993. 相似文献
984.
985.
Helene Gunnarsson Mikael Rönnqvist Dick Carlsson 《Journal of Mathematical Modelling and Algorithms》2007,6(1):25-45
In this paper we consider integrated planning of transportation of raw material, production and distribution of products of the supply chain at Södra Cell AB, a major European pulp mill company. The strategic planning period is one year. Decisions included in the planning are transportation of raw materials from harvest areas to pulp mills, production mix and contents at pulp mills, distribution of pulp products from mills to customer via terminals or directly and selection of potential orders and their levels at customers. Distribution is carried out by three different transportation modes; vessels, trains and trucks. We propose a mathematical model for the entire supply chain which includes a large number of continuous variables and a set of binary variables to reflect decisions about product mix and order selection at customers. Five different alternatives regarding production mix in a case study carried out at Södra Cell are analyzed and evaluated. Each alternative describes which products will be produced at which pulp mills. 相似文献
986.
987.
H. Aoki S. Kosakabe M. Inumaru A. Kuboki S. Ohira M. Kodama 《Journal of Thermal Analysis and Calorimetry》2008,92(2):443-449
D-erythro sphingomyelines (SM) having a defined acyl chain were synthesized with sphingosylphosphorylcholine as a starting material,
and both a structural property and its relating phase transition phenomenon were compared between a symmetric chain length
SM (palmitoyl-SM: C16-SM) and asymmetric chain length SMs (behenoyl-SM: C22-SM, lignoceryl-SM: C24-SM). Furthermore, effect
of increasing a content of asymmetric chain SMs in the mixture systems of C22-SM/C16-SM, and C24-SM/C16-SM was investigated.
The present calorimetric and electron microscopic studies revealed that (1) The main transition enthalpy is smaller for the
asymmetric chain SMs than for the symmetric chain SM by about 3 kJ mol−1, although the acyl chain length is longer for the former than for latter; (2) Relatively small size vesicles (100∼200 nm
diameters) surrounded by one or more lamellae are observed for the asymmetric chain SMs, in contrast to large multilamellar
vesicles (1500∼2500 nm diameters) having at least fifteen stained lamellae for the symmetric chain SM and (3) The coexisting
asymmetric chain SMs cause the decrease in size and multiplicity for the MLV of the symmetric chain SM, simultaneously with
a decrease in the main transition enthalpy. 相似文献
988.
Andreas M. Nyström Jeremy W. Bartels Wenjun Du Karen L. Wooley 《Journal of polymer science. Part A, Polymer chemistry》2009,47(4):1023-1037
Reversible addition‐fragmentation chain transfer polymerization was employed to synthesize a set of copolymers of styrene (PS) and 2,3,4,5,6‐pentafluorostyrene (PPFS), as well as block copolymers with tert‐butyl acrylate (PtBA)‐b‐PS‐co‐PPFS, with control over molecular weight and polydispersity. It was found that the copolymerization of styrene and PFS allowed for the preparation of gradient copolymers with opposite levels of monomer consumption, depending on the feed ratio. Conversion to amphiphilic block copolymers, PAA‐b‐(PS‐co‐PPFS), by removing the protecting groups was followed by fitting with monomethoxy poly(ethylene glycol) chains. Solution‐state assembly and intramicellar crosslinking afforded shell crosslinked knedel‐like (SCK) block copolymer nanoparticles. These fluorinated nanoparticles (ca. 20 nm diameters) were studied as potential magnetic resonance imaging (MRI) contrast agents based on the 19F‐nuclei; however, it was found that packaging of the hydrophobic fluorinated polymers into the core domain restricted the mobility of the chains and prohibited 19F NMR spectroscopy when the particles were dispersed in water without an organic cosolvent. Packing of perflouro‐15‐crown‐5‐ether (PFCE) into the polymer micelle was demonstrated with good uptake efficiency; however, it was necessary to swell the core with a good solvent (DMSO) to increase the mobility and observe the 19F NMR signal of the PFCE. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1023–1037, 2009 相似文献
989.
研究了测度链上的柯西不等式,给出测度链上柯西不等式的具体形式.此外,还对测度链上的柯西不等式作了推广. 相似文献
990.
U. V. Manoj Jatinder N. D Gupta Sushil K. Gupta Chelliah Sriskandarajah 《Annals of Operations Research》2008,161(1):53-86
We study the benefits of coordinated decision making in a supply chain consisting of a manufacturer, a distributor, and several
retailers. The distributor bundles finished goods produced by the manufacturer and delivers them to the retailers to meet
their demands. The distributor is responsible for managing finished goods inventory. An optimal production schedule of the
manufacturer, if imposed on the distributor, may result in an increased inventory holding cost for the distributor. On the
other hand, an optimal distribution schedule of the distributor, if imposed on the manufacturer, may result in an increased
production cost for the manufacturer. In this paper we develop mathematical models for individual optimization goals of the
two partners and compare the results of these models with the results obtained for a joint optimization model at the system
level. We investigate the computational complexities of these scheduling problems. The experimental results indicate that
substantial cost savings can be achieved at the system level by joint optimization. We also study conflict and cooperation
issues in the supply chain. The cost of conflict of a supply chain partner is a measure of the amount by which the unconstrained
optimal cost increases when a decision is to be made under the scheduling constraint imposed by the other partner. We quantify
these conflicts and show that the cost of conflicts are significant. We also show that a cooperative decision will generate
a positive surplus in the system which can be shared by the two partners to make cooperation and coordination strategy more
attractive. 相似文献