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121.
Polykarpos Porfyrakis Nikolaos L. Tsitsas Dimitri J. Frantzeskakis 《Mathematical Methods in the Applied Sciences》2019,42(18):7326-7334
A nonlinear (Kerr‐type) electromagnetic metamaterial, characterized by a double‐Lorentz model of its frequency‐dependent linear effective dielectric permittivity and magnetic permeability, is considered. The formation of gap solitons in the low‐ and high‐frequency band gaps of this metamaterial is investigated analytically. Evolution equations governing the gap solitons, of the form of a nonlinear Klein‐Gordon and a nonlinear Schrödinger equation, are obtained, and the structure of their solutions is discussed. 相似文献
122.
James N. Tsoporis Ioannis-Alexandros Drosatos Sahil Gupta Hajera Amatullah Shehla Izhar Claudia C. dos Santos Vasileos Salpeas Angelos G. Rigopoulos Ioannis K. Toumpoulis Andreas S. Triantafyllis Eleftharios Sakadakis Nikolaos Kavantzas John C. Marshall Ioannis K. Rizos Thomas G. Parker 《Molecules (Basel, Switzerland)》2021,26(13)
DJ-1 was originally identified as an oncogene product while mutations of the gene encoding DJ-1/PARK7 were later associated with a recessive form of Parkinson’s disease. Its ubiquitous expression and diversity of function suggest that DJ-1 is also involved in mechanisms outside the central nervous system. In the last decade, the contribution of DJ-1 to the protection from ischemia-reperfusion injury has been recognized and its involvement in the pathophysiology of cardiovascular disease is attracting increasing attention. This review describes the current and gaps in our knowledge of DJ-1, focusing on its role in regulating cardiovascular function. In parallel, we present original data showing an association between increased DJ-1 expression and antiapoptotic and anti-inflammatory markers following cardiac and vascular surgical procedures. Future studies should address DJ-1’s role as a plausible novel therapeutic target for cardiovascular disease. 相似文献
123.
124.
Schizophrenia is a severe psychiatric disorder affecting up to 1% of the worldwide population. Available therapy presents different limits comprising lack of efficiency in attenuating negative symptoms and cognitive deficits, typical features of schizophrenia and severe side effects. There is pressing requirement, therefore, to develop novel neuroleptics with higher efficacy and safety. Nitric oxide (NO), an intra- and inter-cellular messenger in the brain, appears to be implicated in the pathogenesis of schizophrenia. In particular, underproduction of this gaseous molecule is associated to this mental disease. The latter suggests that increment of nitrergic activity might be of utility for the medication of schizophrenia. Based on the above, molecules able to enhance NO production, as are NO donors, might represent a class of compounds candidates. Sodium nitroprusside (SNP) is a NO donor and is proposed as a promising novel compound for the treatment of schizophrenia. In the present review, we intended to critically assess advances in research of SNP for the therapy of schizophrenia and discuss its potential superiority over currently used neuroleptics. 相似文献
125.
Hisham Ali Jawad Ahmad Zakwan Jaroucheh Pavlos Papadopoulos Nikolaos Pitropakis Owen Lo Will Abramson William J. Buchanan 《Entropy (Basel, Switzerland)》2022,24(10)
Historically, threat information sharing has relied on manual modelling and centralised network systems, which can be inefficient, insecure, and prone to errors. Alternatively, private blockchains are now widely used to address these issues and improve overall organisational security. An organisation’s vulnerabilities to attacks might change over time. It is utterly important to find a balance among a current threat, the potential countermeasures, their consequences and costs, and the estimation of the overall risk that this provides to the organisation. For enhancing organisational security and automation, applying threat intelligence technology is critical for detecting, classifying, analysing, and sharing new cyberattack tactics. Trusted partner organisations can then share newly identified threats to improve their defensive capabilities against unknown attacks. On this basis, organisations can help reduce the risk of a cyberattack by providing access to past and current cybersecurity events through blockchain smart contracts and the Interplanetary File System (IPFS). The suggested combination of technologies can make organisational systems more reliable and secure, improving system automation and data quality. This paper outlines a privacy-preserving mechanism for threat information sharing in a trusted way. It proposes a reliable and secure architecture for data automation, quality, and traceability based on the Hyperledger Fabric private-permissioned distributed ledger technology and the MITRE ATT&CK threat intelligence framework. This methodology can also be applied to combat intellectual property theft and industrial espionage. 相似文献
126.
Sergiu Aizicovici Nikolaos S. Papageorgiou Vasile Staicu 《Journal of Differential Equations》2007,243(2):504-535
We consider a nonlinear periodic problem driven by the scalar p-Laplacian with a nonsmooth potential (hemivariational inequality). Using the degree theory for multivalued perturbations of (S)+-operators and the spectrum of a class of weighted eigenvalue problems for the scalar p-Laplacian, we prove the existence of at least three distinct nontrivial solutions, two of which have constant sign. 相似文献
127.
Plant molecular pharming is a technology that uses plants as bioreactors to produce recombinant molecules of medical and veterinary importance. In the present study, we evaluated the ability of histamine (HIM), tryptamine (TRM), phenylamine (PHEM) and tyramine (TYRM) coupled to Sepharose CL-4B via a 1,4-butanediol diglycidyl ether spacer to bind and purify human monoclonal anti-HIV antibody 2F5 (mAb 2F5) from spiked maize seed and tobacco leaf extracts. Detailed studies were carried out to determine the factors that affect the chromatographic behaviour of mAb 2F5 and also maize seed and tobacco leaf proteins. All affinity adsorbents showed a reduced capacity to bind and a reduced ability to purify proteins from tobacco extract compared to maize extract. Under optimal conditions, HIM exhibited high selectivity for mAb 2F5 and allowed a high degree of purification (>95% purity) and recovery (>90%) in a single step with salt elution (0.4 M KCl) from spiked maize seed extract. Analysis of the purified antibody fraction by ELISA and Western blot showed that the antibody was fully active and free of degraded variants or modified forms. The efficacy of the system was assessed further using a second therapeutic antibody (human monoclonal anti-HIV antibody mAb 2G12) and a therapeutic enzyme (alpha-chymotrypsin). HIM may find application in the purification of a wide range of biopharmaceuticals from transgenic plants. 相似文献
128.
129.
Kai Johannes Keller Nikolaos A. Papadopoulos Andrés F. Reyes-Lega 《Mathematische Semesterberichte》2008,47(10):149-160
The aim of this paper is to give a simple, geometric proof of Wigner’s theorem on the realization
of symmetries in quantum mechanics that clarifies its relation to projective geometry. Although several
proofs exist already, it seems that the relevance of Wigner’s theorem is not fully appreciated in general.
It is Wigner’s theorem which allows the use of linear realizations of symmetries and therefore guarantees
that, in the end, quantum theory stays a linear theory. In the present paper, we take a strictly geometrical
point of view in order to prove this theorem. It becomes apparent that Wigner’s theorem is nothing else
but a corollary of the fundamental theorem of projective geometry. In this sense, the proof presented here
is simple, transparent and therefore accessible even to elementary treatments in quantum mechanics. 相似文献
130.