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排序方式: 共有542条查询结果,搜索用时 15 毫秒
111.
Rigid vinyl can be considered as a highly versatile thermoplastic, finding its way into many different applications. Vinyl's capacity for innovation is virtually limitless, thanks in part to advances in formulation additives, which have enlarged vinyl's processing and end-use performance capabilities. The importance of formulating is particularly evident in rigid cellular PVC, which can be extruded into a variety of shapes, such as profile, pipe, and sheet, all made with less PVC than their solid counterparts. The sheet application can be especially challenging, and it has been made the subject of this paper. The various types of extrusion processes, formulations, and uses for rigid cellular PVC sheet that are found in North America and Europe are compared. The effect of certain types of formulation ingredients on sheet density, surface, and impact strength is described. Reference is made to coextrusion of solid/cellular PVC layers as an economically feasible approach to handling industrial regrind PVC. 相似文献
112.
Attacks on smart cards can only be based on a black box approach where the code of cryptographic primitives and operating system are not accessible. To perform hardware or software attacks, a white box approach providing access to the binary code is more efficient. In this paper, we propose a methodology to discover the romized code whose access is protected by the virtual machine. It uses a hooked code in an indirection table. We gained access to the real processor, thus allowing us to run a shell code written in 8051 assembly language. As a result, this code has been able to dump completely the ROM of a Java Card operating system. One of the issues is the possibility to reverse the cryptographic algorithm and all the embedded countermeasures. Finally, our attack is evaluated on different cards from distinct manufacturers. 相似文献
113.
Electrochemical DNA aptamer-based biosensor for OTA detection, using superparamagnetic nanoparticles 总被引:3,自引:0,他引:3
Lise BarthelmebsAuthor Vitae Akhtar HayatAuthor VitaeAmbrosius Wis LimiadiAuthor Vitae Jean-Louis MartyAuthor VitaeThierry NoguerAuthor Vitae 《Sensors and actuators. B, Chemical》2011,156(2):932-937
A novel electrochemical aptasensor, based on disposable screen-printed electrodes was developed for the sensitive detection of the mycotoxin ochratoxin A (OTA). Two strategies were investigated by using an indirect and a direct competitive assay, based on the use of superparamagnetic nanoparticles. The performance of the optimized aptasensors in terms of reproducibility, stability, sensitivity, and analysis time was studied. The best strategy was found to be the direct competitive format. In this assay, free OTA competed with labeled alkaline phosphatase-OTA for the binding to the DNA aptamer immobilized on magnetic beads. The electrochemical detection was thus achieved through a suitable substrate for the enzyme ALP, by Differential Pulse Voltammetry. The aptasensor obtained using this novel approach allowed detection limit of 0.11 ng/mL, and was also validated for real sample analysis. 相似文献
114.
José Echeveste Arshia Cont Jean-Louis Giavitto Florent Jacquemard 《Discrete Event Dynamic Systems》2013,23(4):343-383
With the advent and availability of powerful personal computing, the computer music research and industry have been focusing on real-time musical interactions between musicians and computers; delegating human-like actions to computers who interact with a musical environment. One common use-case of this kind is Automatic Accompaniment where the system is comprised of a real-time machine listening system that in reaction to recognition of events in a score from a human performer, launches necessary actions for the accompaniment section. While the real-time detection of score events out of live musicians’ performance has been widely addressed in the literature, score accompaniment (or the reactive part of the process) has been rarely discussed. This paper deals with this missing component in the literature from a formal language perspective. We show how language considerations would enable better authoring of time and interaction during programming/composing and how it addresses critical aspects of a musical performance (such as errors) in real-time. We sketch the real-time features required by automatic musical accompaniment seen as a reactive system. We formalize the timing strategies for musical events taking into account the various temporal scales used in music. Various strategies for the handling of synchronization constraints and the handling of errors are presented. We give a formal semantics to model the possible behaviors of the system in terms of Parametric Timed Automata. 相似文献
115.
Llorens I Lahera E Delnet W Proux O Braillard A Hazemann JL Prat A Testemale D Dermigny Q Gelebart F Morand M Shukla A Bardou N Ulrich O Arnaud S Berar JF Boudet N Caillot B Chaurand P Rose J Doelsch E Martin P Solari PL 《The Review of scientific instruments》2012,83(6):063104
Fluorescence detection is classically achieved with a solid state detector (SSD) on x-ray absorption spectroscopy (XAS) beamlines. This kind of detection however presents some limitations related to the limited energy resolution and saturation. Crystal analyzer spectrometers (CAS) based on a Johann-type geometry have been developed to overcome these limitations. We have tested and installed such a system on the BM30B/CRG-FAME XAS beamline at the ESRF dedicated to the structural investigation of very dilute systems in environmental, material and biological sciences. The spectrometer has been designed to be a mobile device for easy integration in multi-purpose hard x-ray synchrotron beamlines or even with a laboratory x-ray source. The CAS allows to collect x-ray photons from a large solid angle with five spherically bent crystals. It will cover a large energy range allowing to probe fluorescence lines characteristic of all the elements from Ca (Z = 20) to U (Z = 92). It provides an energy resolution of 1-2 eV. XAS spectroscopy is the main application of this device even if other spectroscopic techniques (RIXS, XES, XRS, etc.) can be also achieved with it. The performances of the CAS are illustrated by two experiments that are difficult or impossible to perform with SSD and the complementarity of the CAS vs SSD detectors is discussed. 相似文献
116.
This paper presents a theoretical study of the failure rate behavior of components subjected to random environmental stresses. Three kinds of stresses are considered: point, alternating, diffused. The concept that the component could memorize the stress is introduced. Diverse types of stress action can thus be defined: instantaneous, cumulative, recovering. Two classes of stochastic models are proposed, which express the effect of stress to the lifetime of the component. Several examples for which the resulting failure rate has an explicit expression, are presented. In most of these examples, the failure rate converges rapidly to a constant, that confirms a conjecture frequently made by the engineers. 相似文献
117.
Christophe Duthoit Jean-Louis Armand 《International journal for numerical methods in engineering》1989,27(1):169-183
The dynamic behaviour of marine vehicles in extreme sea states is a matter of great concern following some recent and dramatic mishaps. The complex problem of its prediction can be approached from the study, yet of broader scope, of non-linear dynamic systems subjected to stochastic excitations. However, a general non-linear stochastic dynamic theory is not yet available. A new technique, the so-called linearize-and-match method, for predicting the response statistics of non-linear systems, is presented. Essentially, the technique involves the construction of an infinite series of linear systems aimed at the prediction of the response statistical moments of a given order. The linear systems are successively defined by linearizing the original, non-linear system and matching the Volterra functional model response statistics to the desired order. The linear system for predicting second order statistics is shown to coincide with the one obtained using the method of equivalent linearization. Response probability distributions can be constructed from the knowledge of such statistics. Particular attention is devoted to the distribution of maximum entropy and its justification in such underdetermined moment problems. Finally, applications to the roll motion of ships serve to exemplify as well as to assess the accuracy and the versatility of the overall method. Response distributions of maxima so predicted compare very well with digital simulation estimates. 相似文献
118.
Anne Sibille Jean-Louis Corhay Renaud Louis Vincent Ninane Guy Jerusalem Bernard Duysinx 《International journal of molecular sciences》2022,23(9)
Eosinophils are rare, multifunctional granulocytes. Their growth, survival, and tissue migration mainly depend on interleukin (IL)-5 in physiological conditions and on IL-5 and IL-33 in inflammatory conditions. Preclinical evidence supports an immunological role for eosinophils as innate immune cells and as agents of the adaptive immune response. In addition to these data, several reports show a link between the outcomes of patients treated with immune checkpoint inhibitors (ICI) for advanced cancers and blood eosinophilia. In this review, we present, in the context of non-small cell lung cancer (NSCLC), the biological properties of eosinophils and their roles in homeostatic and pathological conditions, with a focus on their pro- and anti-tumorigenic effects. We examine the possible explanations for blood eosinophilia during NSCLC treatment with ICI. In particular, we discuss the value of eosinophils as a potential prognostic and predictive biomarker, highlighting the need for stronger clinical data. Finally, we conclude with perspectives on clinical and translational research topics on this subject. 相似文献
119.
Yves Lecarpentier Victor Claes Jean-Louis Hbert Xnophon Krokidis Olivier Schussler Alexandre Valle 《International journal of molecular sciences》2022,23(13)
Contraction of the heart is caused by actin filaments sliding along myosin filaments. This generates a frictional force inducing wear of the contractile apparatus. We postulated that this process could be exacerbated when the heart was submitted to severe anoxia. Anoxia induced dramatic abnormalities in the molecular properties of actin-myosin crossbridges. We applied the formalism of far-from-equilibrium thermodynamics to the left ventricular papillary muscles (LVPMs) of mammalian rat hearts which had been subjected to a prolonged anoxia (3 h). We showed that when subjected to prolonged anoxia, the heart operated far-from-equilibrium as evidenced by the non-linearity between thermodynamic force (F/T: Frictional force/Kelvin temperature) and thermodynamic flow (v0: myofilament sliding velocity). The rate of entropy production (EPR) was the product of (F/T) and v0. The excess entropy production (EEP) was equal to = vo; (S: entropy). The tribological system remained stable when EEP was positive and became unstable when EEP became negative, thus characterizing instability of the system and reflecting the occurrence of self-organization and possibly dissipative structures. After 3 h anoxia, re-oxygenation induced significant reversibility. About 20% of the myosin heads did not recover despite re-oxygenation. These results may be of importance in the context of heart transplantation where the delay between the time of sampling from the donor and the time of the graft installation in the recipient should be as short as possible. 相似文献
120.
Olfa Harki Sophie Bouyon Marine Sall Alejandro Arco-Hierves Emeline Lemari Alexandra Demory Carole Chirica Isabelle Vilgrain Jean-Louis Ppin Gilles Faury Anne Brianon-Marjollet 《International journal of molecular sciences》2022,23(13)
Intermittent hypoxia (IH), the major feature of obstructive sleep apnea syndrome (OSAS), induces atherosclerosis and elastic fiber alterations. VE-cadherin cleavage is increased in OSAS patients and in an IH-cellular model. It is mediated by HIF-1 and Src-tyr-kinases pathways and results in endothelial hyperpermeability. Our aim was to determine whether blocking VE-cadherin cleavage in vivo could be an efficient strategy to inhibit deleterious IH-induced vascular remodeling, elastic fiber defects and atherogenesis. VE-cadherin regulation, aortic remodeling and atherosclerosis were studied in IH-exposed C57Bl/6J or ApoE-/-mice treated or not with Src-tyr-kinases inhibitors (Saracatinib/Pazopanib) or a HIF-1 inhibitor (Acriflavine). Human aortic endothelial cells were exposed to IH and treated with the same inhibitors. LDL and the monocytes transendothelium passage were measured. In vitro, IH increased transendothelium LDL and monocytes passage, and the tested inhibitors prevented these effects. In mice, IH decreased VE-cadherin expression and increased plasmatic sVE level, intima-media thickness, elastic fiber alterations and atherosclerosis, while the inhibitors prevented these in vivo effects. In vivo inhibition of HIF-1 and Src tyr kinase pathways were associated with the prevention of IH-induced elastic fiber/lamella degradation and atherogenesis, which suggests that VE-cadherin could be an important target to limit atherogenesis and progression of arterial stiffness in OSAS. 相似文献