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101.
S. Mohammad Sajadi Kamal Kolo Samir M. Hamad Sarbast A. Mahmud Mohammad Pirouei Keyvan Amjadian Karzan M. Khalid 《IET nanobiotechnology / IET》2019,13(2):124
For the first time, through a fast, eco‐friendly and economic method, the aqueous extract of the leaf of Euphorbia corollate was used to the green synthesis of the highly stable CuO@Magnetite@Hen Bone nanocomposites (NCs) as a potent antioxidant and antibacterial agent against Pseudomonas aureus, Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae pathogenic bacteria. The biosynthesised NCs were identified using the scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy, elemental mapping, X‐ray diffraction (XRD), Fourier transforms infrared spectroscopy and UV–vis analytical techniques. Also, the radical scavenging activity using (2,2‐diphenyl‐1‐picrylhydrazyl) method was used to evaluate the antioxidant activity of the NCs. The stability of nanocatalyst was monitored using the XRD and SEM analyses after 30 days from its synthesis. Furthermore, its excellent catalytic activity, recycling stability, and high substrate applicability were demonstrated to the adsorption of the polycyclic aromatic hydrocarbons of the light crude oil from Shiwashok oil fields and destruction of methylene blue and methyl orange as harmful organic dyes at ambient temperature using UV–vis spectroscopy. Moreover, the green CuO@Magnetite@Hen Bone NCs were recovered and reused several times without considerable loss of its catalytic activity.Inspec keywords: nanobiotechnology, X‐ray diffraction, infrared spectra, catalysis, crude oil, Fourier transform spectra, ultraviolet spectra, scanning electron microscopy, dyes, catalysts, photochemistry, iron compounds, X‐ray chemical analysis, antibacterial activity, adsorption, visible spectra, microorganisms, organic compounds, reduction (chemical), nanomedicine, toxicology, recycling, chemical industryOther keywords: antioxidant activity, XRD, SEM analyses, recycling stability, polycyclic aromatic hydrocarbons, harmful organic dyes, UV–vis spectroscopy, green CuO@Magnetite@Hen Bone NCs, reusable CuO@Magnetite@Hen Bone NCs, recyclable CuO@Magnetite@Hen Bone NCs, antioxidant activities, antibacterial activities, highly stable magnetically nanocatalyst, eco‐friendly method, economic method, euphorbia corollate, green synthesis, CuO@Magnetite@Hen Bone nanocomposites, antibacterial agent, pseudomonas aureus, staphylococcus aureus, escherichia coli, klebsiella pneumoniae pathogenic bacteria, biosynthesised NCs, X‐ray spectroscopy, X‐ray diffraction, radical scavenging activity, antioxidant agent, 2,2‐diphenyl‐1‐picrylhydrazyl, catalytic activity, organic dye reduction, light crude oil, CuO 相似文献
102.
Khalid Kassara 《Systems & Control Letters》2000,40(4):507
The paper shows, for the first time that a feedback spreading control law for semilinear distributed parameter systems with compact linear operator can be provided by a selection procedure which involves both the dynamics of the system and the property to be spread. In the case of affine dependence upon the control a minimum energy feedback spreading control law will be derived by using a parametrized constrained optimization technique along with some facts of set-valued analysis. 相似文献
103.
The introduction of new service categories withdifferent bandwidth requirements, e.g., data and multimedia, to cellularmobile radio networks makes many of the traditional mechanisms for controlingtraffic unusable orless efficient. The call admission and the handover handling are of the mostsensitive issues in this extension to new services. The performance of allservices includingthe traditional voice and the new services can be dramatically affected ifappropriate schemes are not used. In this paper, we propose call admission andhandover handling schemes for a cellular mobile network that offers twoservice types: voice and data. The data connections are assumed to transmitatdifferent transmission rates that are integer multiples to that of one radiochannel. In the case of congestion, the base station asks the active dataconnections to reduce their transmission rate in order to provide freechannels for the newly arrived request of both service types. This isbasically intended for incoming handover requests. The request will berejected if the transmission rate of the active connections reaches a givenminimum rate. Similar mechanism can also be used for new call arrivals, butsome priority can be given to handovers by setting a higher transmission ratethreshold for the new call rejection. As an extension to the proposedscalability, aqueuing of new calls is also proposed and analyzed. Analytical models werebuilt for the two proposed schemes together with the traditional channelreservation scheme. The effect of different traffic and configurationparameters on the performance measures like the grade of service, blockingprobabilities, and utilization, are studied using the proposed technique.Results show that the proposed schemes provide very good performance and morefairness among the different service types. 相似文献
104.
The influences of the exchange complex and pH of the solution used for cation saturation on Atterberg limits, compaction, and swelling potential of a compacted clay were investigated. The study involved transforming the exchange complex from a heterogeneous to a homogeneous one so that a frame of reference can be set for the clay behavior under such an ideal condition. The employed method for altering the exchange complex successfully yielded homo-ionic clay. The introduction of different species of cations gave rise to different particles associations. When introduced to the tested clay, potassium cations bond its particles with a rather strong bond (K-linkage), causing a drastic decrease in the specific area of the clay (about one-fourth of its untreated specific area), a decrease in the CEC, as well as a drastic decrease in the swell potential. For example, the swell pressure decreased from 1.87 kg/cm2 for the untreated samples to 0.4 kg/cm2 for the K-treated samples (under the same conditions). Also, the swell potential vs. time relationships can be modeled accurately using a rectangular hyperbola. 相似文献
105.
Fast computation of accurate Zernike moments 总被引:2,自引:0,他引:2
Khalid M. Hosny 《Journal of Real-Time Image Processing》2008,3(1-2):97-107
Zernike polynomials are continuous orthogonal polynomials defined in polar coordinates over a unit disk. Zernike moment’s computation using conventional methods produced two types of errors namely approximation and geometrical. Approximation errors are removed by using exact Zernike moments. Geometrical errors are minimized through a proper mapping of the image. Exact Zernike moments are expressed as a combination of exact radial moments, where exact values of radial moments are computed by mathematical integration of the monomial polynomials over digital image pixels. A fast algorithm is proposed to accelerate the moment’s computations. A comparison with other conventional methods is performed. The obtained results explain the superiority of the proposed method. 相似文献
106.
Khalid Al‐Osaimi Abdulmohsen Alheraish Saad Haj Bakry 《International Journal of Network Management》2008,18(1):65-75
The STOPE‐based approach is used here for practical e‐readiness assessment case studies. The approach integrates and evaluates the various e‐readiness assessment issues, over its well‐structured domains: strategy, technology, organization, people, and environment. The case studies considered concern three Saudi organizations: a government organization, a bank, and a private sector company. The results obtained provide e‐readiness indicators that illustrate the strengths and weaknesses of each organization with regard to e‐readiness strategic development issues, information and communication technology (ICT) issues, management and organization issues, people issues, and environment issues within which the organization operates. The work shows how the approach can be practically used, and it also provides practical results that direct the organizations concerned toward enhancing their e‐readiness in response to the current trend of globalizing e‐business. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
107.
Performing deep excavations in karst regions is likely lead to geo-hazards, e.g. sinkholes, water ingress, and ground surface settlement. This case report presents the performance of a 16-m deep excavation in sand covered karst in Metro Line no. 9, Guangzhou, China. The performances during deep excavation, including lateral wall deflection, vertical wall movement, ground surface settlement, and settlement of adjoining buildings, were monitored and evaluated. Based upon the interpretation of the field measurements, the following major findings were obtained: (i) the lateral wall deflection and surface settlement measurements were smaller those cited in other case studies with similar geological conditions, (ii) both the grouting of the karst cavern and the use of the socket diaphragm wall panel dominated the performance of the deep excavation; (iii) the type of the founding structure could significantly affect the settlement development of the adjoining buildings. This case report provides insight into the design and construction of deep, narrow excavations in sand covered karst in a metropolitan environment. 相似文献
108.
Experimental investigation of a new type of interfacial instability in a reactive coextrusion process
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Arnaud Bondon Khalid Lamnawar Abderrahim Maazouz 《Polymer Engineering and Science》2015,55(11):2542-2552
This paper deals with the study of new interfacial instabilities, called “grainy” defects, in coextrusion process of reactive multilayer polymers. The main objective was to better understand this phenomenon since no help can be found in the literature. The fundamental approach from a micro‐scale to a macro‐scale involves the study of relationships between polymer structure, processing, and interfacial properties. The influence of these parameters on the generation of “grainy” defects during coextrusion has been assessed in correlation with physicochemical properties. Through this work, rheological properties and the interfacial morphology between tie and barrier layers have been investigated by shear stress relaxation experiments and transmission electronic microscopy, respectively. Depending on the reactive polymers, the interfacial coupling was found to significantly alter the stress relaxation behavior by extending the relaxation time and generating an interfacial roughness. Hence, relations between the copolymer architecture, the relaxation process, and the interfacial morphology were established in correlation with the generation of grainy defects in coextrusion process. POLYM. ENG. SCI., 55:2542–2552, 2015. © 2015 Society of Plastics Engineers 相似文献
109.
pH‐Cleavable Nucleoside Lipids: A New Paradigm for Controlling the Stability of Lipid‐Based Delivery Systems
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Dr. Khalid Oumzil Sébastien Benizri Giovanni Tonelli Dr. Cathy Staedel Ananda Appavoo Max Chaffanet Laurence Navailles Prof. Philippe Barthélémy 《ChemMedChem》2015,10(11):1797-1801
Lipid‐based delivery systems are an established technology with considerable clinical acceptance and several applications in human. Herein, we report the design, synthesis and evaluation of novel orthoester nucleoside lipids (ONLs) for the modulation of liposome stability. The ONLs contain head groups with 3′‐orthoester nucleoside derivatives featuring positive or negative charges. The insertion of the orthoester function in the NL structures allows the formation of pH‐sensitive liposomes. ONL‐based liposomes can be hydrolyzed to provide nontoxic products, including nucleoside derivatives and hexadecanol. To allow the release to be tunable at different hydrolysis rates, the charge of the polar head structure is modulated, and the head group can be released at a biologically relevant pH. Crucially, when ONLs are mixed with natural phosphocholine lipids (PC), the resultant liposome evolves toward the formation of a hexadecanol/PC lamellar system. Biological evaluation shows that stable nucleic acid lipid particles (SNALPs) formulated with ONLs and siRNAs can effectively enter into tumor cells and release their nucleic acid payload in response to an intracellular acidic environment. This results in a much higher antitumor activity than conventional SNALPs. The ability to use pH‐cleavable nucleolipids to control the stability of lipid‐based delivery systems represents a promising approach for the intracellular delivery of drug cargos. 相似文献
110.
Propoxylated Fatty Thiazole,Pyrazole, Triazole,and Pyrrole Derivatives with Antimicrobial and Surface Activity
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Lauric acid and propylene oxide were used to modify four biologically active heterocycles (thiazole, pyrazole, triazole, and pyrrole) to synthesize 17 new surfactants. The chemical structures of these surfactants were confirmed using infrared and 1H, and 13C nuclear magnetic resonance (NMR) spectroscopy. The surfactants all show good surface activity, low critical micelle concentration (CMC) values, high cloud points, and tight interfacial packing. All showed antimicrobial activity on both bacteria and fungi. In addition, biodegradation testing demonstrated significant breakdown within seven days. 相似文献