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991.
This paper studies the robust output tracking for heterogeneous double-integrator dynamics with external disturbance. It is assumed that there exist interactions among agents and their neighbours. All the agents have non-identical dynamics with others, and all the system matrices are unknown. A state feedback control protocol with only neighbours information is proposed based on a distributed compensator for non-identical dynamics and an internal-model compensator for the unknown parts. By the algebraic graph theory and matrix theory, sufficient conditions are given to guarantee that all the outputs of the agents converge to the reference output as time tends to infinity. Finally, two numerical simulations are provided to illustrate the effectiveness of the theoretical results. 相似文献
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In an attempt to remain competitive, manufacturers increasingly offer integrated product-service systems (PSSs). This transition from physical products to PSSs calls for new ways of working, for example in the product development process. However, so far only limited attention has been put on capabilities needed to succeed with PSS innovation in the very early development phases – often referred to as the fuzzy front end (FFE). This article, therefore, has a dual aim: first, to further our understanding of capabilities for PSS innovation in the FFE, and second, to determine how these capabilities are linked to PSS innovation capabilities needed in subsequent development phases. Empirical data were collected from an ongoing industrial project developing an innovative PSS offering in a large manufacturing company. Individuals connected to the project reported major challenges, both experienced in the FFE and anticipated in later phases, which provided valuable information regarding capabilities needed to succeed with the endeavour. Findings reveal four links of PSS innovation capabilities: (1) adapting vocabulary and mental models to PSS, (2) handling the ‘intangible aspect’, (3) bridging organisational structures, and (4) managing new business models. PSS innovation capabilities in the FFE are also found to be of higher order (dynamic) compared to capabilities in later development phases. 相似文献
995.
Piotr Kamedulski Anna Kaczmarek-Kedziera Jerzy P Lukaszewicz 《Bulletin of Materials Science》2018,41(3):76
This study is aiming at theoretical and experimental confirmations of the deposition of oligothiophene dyes (OT) on structurally and chemically diverse surfaces of carbon materials, especially carbon nanotubes (CNTs). This study is a contribution to the wide search and design of novel hybrid materials for light-sensitive (dye solar cells) and light-emitting (LEDs) structures. The obtained materials containing OTs embedded in the pores of a carbon matrix were analysed by means of microscopic and spectroscopic techniques as well as low-temperature adsorption of nitrogen, together with an investigation of the surface area by the BET method. Confocal microscopy was employed to confirm the immobilization of oligomers on the surface of CNTs. Raman spectra, XRD and HTEM microscopies allowed to judge the quality of the carbonaceous material and to compare the test material before and after the introduction of OT. Additionally, the elemental content and elemental surface species were determined by means of XPS and combustion elemental analyses. The explanation of thiophene; 2,2\(^\prime \):5\(^\prime \),2\({^{\prime \prime }}\)-terthiophene and \(\alpha \)-sexithiophene molecular interactions with single wall armchair CNTs was supported by theoretical calculations. In computational investigations, CNTs were modelled by tubules of different sizes, lengths and hydrogenated open ends. 相似文献
996.
Anna Maria Piras Ylenia Zambito Susi Burgalassi Daniela Monti Silvia Tampucci Eleonora Terreni Angela Fabiano Federica Balzano Gloria Uccello-Barretta Patrizia Chetoni 《Journal of materials science. Materials in medicine》2018,29(4):42
The ocular bioavailability of lipophilic drugs, such as dexamethasone, depends on both drug water solubility and mucoadhesion/permeation. Cyclodextrins and chitosan are frequently employed to either improve drug solubility or prolong drug contact onto mucosae, respectively. Although the covalent conjugation of cyclodextrin and chitosan brings to mucoadhesive drug complexes, their water solubility is restricted to acidic pHs. This paper describes a straightforward grafting of methyl-β-cyclodextrin (MCD) on quaternary ammonium chitosan (QA-Ch60), mediated by hexamethylene diisocyanate. The resulting product is a water-soluble chitosan derivative, having a 10-atom long spacer between the quaternized chitosan and the cyclodextrin. The derivative is capable of complexing the model drug dexamethasone and stable complexes were also observed for the lyophilized products. Furthermore, the conjugate preserves the mucoadhesive properties typical of quaternized chitosan and its safety as solubilizing excipient for ophthalmic applications was preliminary assessed by in vitro cytotoxicity evaluations. Taken as a whole, the observed features appear promising for future processing of the developed product into 3D solid forms, such as controlled drug delivery systems, films or drug eluting medical devices. 相似文献
997.
An increasing number of products are equipped with software and sensors. This suggests that, in order to deliver more customised performance, future products will be developed to accommodate systems that supply information on how these products are used. Today, information on the customer’s way of using a product is seldom factored into product design, but the opportunities for making use of it are increasing dramatically due to the amount of available data that can be logged. The proposed methodology is to formulate Customer Needs at a detailed level to be able to link customer satisfaction with a clear interface to the Design Requirements. These links are obtained by combining information acquired by means of surveys, among other methodologies, as well as usage data from customer products. The method is based on the planning House of Quality and also takes cost and risk into consideration. Risk is estimated using the Analytical Hierarchy Process, whereby a hierarchy of the most relevant customer information is constructed to make designers aware of how customer-focused the design process is. To validate the proposed methodology an illustrative example is presented. Results show that the method provides valuable information that enables the company to remain customer-focused during the whole process but also when strategic decisions on price and product launch are made. 相似文献
998.
Tomasz Osmałek Bartłomiej Milanowski Anna Froelich Mirosław Szybowicz Wojciech Białowąs Marcin Kapela 《Drug development and industrial pharmacy》2017,43(8):1314-1329
The aim of the presented work was to design, formulate and evaluate the properties of low-acyl gellan macro beads with the potential application as carriers for oral delivery of meloxicam (MLX) in the prophylaxis of colorectal cancer. The beads were obtained by means of ionotropic gelation technique. Calcium chloride (1.0%, 9.0?×?10?2 M) was used as the cross-linking agent. Nine different polymer, drug and surfactant (Tween®80) mixtures were used for production of the beads. The quantitative compositions of the mixtures were generated with the application of the Design of Experiments (DoE) modulus from the STATISTICA Software. The prepared formulations revealed 7.2–27.0% of drug loading and 29.2–50.7% drug encapsulation efficiency. It turned out that 0.5% amount of gellan gum in the mixtures was not sufficient to obtain spherical beads. The morphology and surface of the dried beads were analyzed by SEM. Raman spectra confirmed that MLX did not undergo structural changes during production of the beads. The swelling behavior and degradation of the beads were evaluated in three simulated gastrointestinal fluids at different pH (1.2; 4.5; 6.8). The MLX in vitro release studies were conducted on USP apparatus IV, working in the open loop mode. The obtained results showed that MLX release from the dried beads was pH-dependent. The formulations obtained from mixtures containing 1.0 and 1.5% of gellan may be considered as oral dosage forms for MLX, intended to omit the stomach and release the drug in the distal parts of the gastrointestinal tract. 相似文献
999.
Yagmur Akdag Cayli Selma Sahin Francesca Buttini Anna Giulia Balducci Serena Montanari Imran Vural 《Drug development and industrial pharmacy》2017,43(8):1378-1389
Objective: This study aimed to design and characterize an inhalable dry powder of ciprofloxacin or levofloxacin combined with the mucolytics acetylcysteine and dornase alfa for the management of pulmonary infections in patients with cystic fibrosis.Methods: Ball milling, homogenization in isopropyl alcohol and spray drying processes were used to prepare dry powders for inhalation. Physico-chemical characteristics of the dry powders were assessed via thermogravimetric analysis, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry and scanning electron microscopy. The particle size distribution, dissolution rate and permeability across Calu-3 cell monolayers were analyzed. The aerodynamic parameters of dry powders were determined using the Andersen cascade impactor (ACI).Results: After the micronization process, the particle sizes of the raw materials significantly decreased. X-ray and DSC results indicated that although ciprofloxacin showed no changes in its crystal structure, the structure of levofloxacin became amorphous after the micronization process. FT-IR spectra exhibited the characteristic peaks for ciprofloxacin and levofloxacin in all formulations. The dissolution rates of micro-homogenized and spray-dried ciprofloxacin were higher than that of untreated ciprofloxacin. ACI results showed that all formulations had a mass median aerodynamic diameter less than 5?μm; however, levofloxacin microparticles showed higher respirability than ciprofloxacin powders did. The permeability of levofloxacin was higher than those of the ciprofloxacin formulations.Conclusion: Together, our study showed that these methods could suitably characterize antibiotic and mucolytic-containing dry powder inhalers. 相似文献