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71.
Takayoshi Katahira Ilkka Kartio Hiroshi Segawa Michimasa Takahashi Katsumi Sagisaka 《Microelectronics Reliability》2006,46(5-6):756-762
There are several PWB technologies in the market that enables high density interconnection for product miniaturization, and this paper focuses on two HDI technologies, SSP and FVSS®, and discuss the new PWB technologies and the reliability evaluation results for mobile applications. SSP is manufactured in simple lamination process using conventional FR4 materials, which enables future cost reduction and high reliability. FVSS contains filled buried via hole (BVH) and filled micro blind via (μvia) process. By combining the two process FVSS accomplishes high vertical design capability with Stacked μvia-on-μvia and stacked μvia-on-BVH designs.Key reliability requirements for final product quality is drop and temperature cycling reliability in board level in addition to evaluate PWB specific tests to compare performance of new materials used in PWB. 相似文献
72.
We study the effect of tissue anisotropy in optical tomography of neonates. A Monte Carlo method capable of modeling photon migration in an arbitrary 3D tissue model with spatially varying optical properties and tissue anisotropy is used for simulating measurements of neonates. Anatomical and diffusion tensor magnetic resonance imaging of neonates are used for creating the anatomical models. We find that tissue anisotropy affects the measured signal and the pattern of sensitivity in optical measurements. 相似文献
73.
Uurto I Kotsar A Isotalo T Mikkonen J Martikainen PM Kellomäki M Törmälä P Tammela TL Talja M Salenius JP 《Journal of materials science. Materials in medicine》2007,18(8):1543-1547
Drug-eluting stents are a recent innovation for endovascular and endourethral purposes. The aim of this study was to assess
the biocompatibility of new biodegradable drug-eluting stent materials in vivo. Rods made of SR-PLDLA (self-reinforced poly-96l,4d-lactic acid) covered with P(50l/50d)LA and rods made of 96l/4D SR-PLA and covered with P(50l/50d)LA including indomethacin 3.3 μg/mm2 or dexamethasone 1.5 μg/mm2, were inserted into the dorsal muscles of 20 rabbits serving as test animals. Rods made of silicone and organotin-positive
polyvinylchloride were used as negative and positive controls. The animals were sacrificed after 1 week, 1 month, 2 months
or 4 months. Histological changes attributable to the operative trauma were seen in all specimens at 1 week and 1 month. At
2 months both dexamethasone and indomethacin induced less fibrosis than the plain SR-PLDLA covered with P(50l/50d)LA without drug. At 4 months dexamethasone induced both chronic inflammatory changes and foreign body reaction, whereas the
reactions in the indomethacin and drug-free plain SR-PLDLA groups were insignificant. The new biodegradable drug-eluting stent
materials are highly biocompatible. Drug-eluting biodegradable stents may offer a promising new treatment modality for vascular
and urethral diseases. However, further studies are needed to demonstrate their feasibility and efficacy. 相似文献
74.
Handolin L Partio EK Arnala I Pajarinen J Pätiälä H Rokkanen P 《Journal of materials science. Materials in medicine》2007,18(6):1239-1245
The effects of low-intensity pulsed ultrasound (30 mW/cm2) were investigated in experimental cancellous bone fracture healing in bioabsorbable self-reinforced poly-l-lactide (SR-PLLA) rod fixed distal femur osteotomy in rats. A transverse transcondylar osteotomy was fixed with one SR-PLLA
rod in 32 male Wistar rats of the age of 20 weeks. Half of the rats had a daily 20-min ultrasound exposure for three weeks.
The follow-up times were three, six, and 12 weeks. Radiographical, histological, microradiographical, oxytetracycline labeling,
and histomorphometrical analyses were performed. No foreign-body reactions were noted. The biocompatibility of SR-PLLA and
ultrasound was found to be good. In the radiological and histological assessments there was a slight tendency for enhanced
healing in the ultrasound group at three weeks, but at six and 12 weeks no differences were observed. The histomorphometrical
and oxytetracycline labeling analyses showed that ultrasound exposure had no significant effects on bone healing.
The present study shows that there were no obvious findings to support the hypothesis that low-intensity pulsed ultrasound
enhances bone healing in self-reinforced poly-l-lactide (SR-PLLA) rod fixed experimental metaphyseal distal femur osteotomy in rats. The observed good biocompatibility provides
a safe starting-point for clinical trials on bioabsorbable fixation combined with low-intensity ultrasound. 相似文献
75.
Benjamin Manrique Delgado Sunliang Cao Ala Hasan Kai Sirén 《Building Research & Information》2018,46(6):668-685
Surplus energy can be a recurrent phenomenon in zero-energy buildings (ZEBs) with onsite generation systems, usually resulting in the export of excess electricity. Yet, converting electricity into heat and exporting it could improve the overall energy balance. This study analyses the energy and exergy performance of a Finnish nearly zero-energy building (nZEB) as a heat and electricity prosumer, and proposes alternative energy topologies to improve energy and exergy levels, primary energy demand and CO2 emissions. The results show that increasing the installed capacity of the photovoltaic systems would lead to zero energy, exergy, emissions and a balance of primary energy. However, by instead using the surplus electricity to drive a heat pump and export heat, the currently installed capacity would lead to a net energy export of over 4000?kWh/a. Thus, energy conversion could significantly enhance the contribution from heat and electricity prosumers to smart energy grids, though not without affecting other criteria. Two management strategies arise: favouring heat export improves the net energy and CO2 emissions reduction but lessens the net exergy, while favouring electricity export improves the net exergy and primary energy reduction. The findings highlight that energy conversion can enhance nZEB performance and its exchange with hybrid grids. 相似文献
76.
Experimental measurements were carried out to compare the air-side heat transfer coefficients of three oval tubes (axis ratio 2, 3, and 4) with those of an equivalent circular tube (o. d. 18 mm). The tubes were tested as single tubes in a cross-flow of air. The range of the investigated Reynolds numbers Re D was between 1000 and 11000. The effects of the area blockage and the free stream turbulence were taken into consideration in the evaluation of the thermal performance. The measurement results indicate that Nusselt numbers Nu D for the tested circular and oval tubes are close at the lower range of the tested Reynolds numbers (Re D < 4000) corresponding to an air velocity < 4 ms ?1 in this work, which is the air velocity for most air conditioning applications. For Re D > 4000, the Nu D for the circular tube are higher than those for the oval tubes, and the Nu D for the oval tubes decrease with the increase of the axis ratio. 相似文献
77.
Davood Gudarzi Warin Ratchananusorn Ilkka Turunen Tapio Salmi Markku Heinonen 《Topics in Catalysis》2013,56(9-10):527-539
Activated carbon cloths (ACCs) were used as supports for Pd catalysts. The catalyst preparation was carried out by the impregnation method using acidic solution of palladium dichloride (PdCl2) as metal precursor. The effects of the oxidation state of the loaded metal, heat treatment of the catalysts in different atmosphere (H2, air) at different temperatures and surface chemistry of the support on the catalyst characterizations and the catalytic activities were investigated. Wet oxidation of ACC was done by nitric acid in order to induce oxygen-containing surface functional groups. Surface chemistry of the support and oxidation state of the metallic phase was investigated by means of XPS, TPD, SEM, DTA and TGA tests. Direct synthesis of hydrogen peroxide from H2 and O2 was performed batch wise in a stainless steel autoclave. The reactions were conducted under high pressure (38 bar) at 0 °C and methanol was used as reaction medium. The direct synthesis results showed that the oxygen-containing surface functional groups increase the selectivity of the catalysts by reducing the rate of water production. Existence of the oxidized state of Pd (PdO) also makes the catalyst more selective than the corresponding zerovalent state (Pd0). PdO affected on selectivity by increasing the rate of H2O2 production and reducing the amount of production of water, simultaneously. 相似文献
78.
Electrochemical treatment of the antibiotic sulfachloropyridazine: kinetics, reaction pathways, and toxicity evolution 总被引:2,自引:0,他引:2
Dirany A Sirés I Oturan N Ozcan A Oturan MA 《Environmental science & technology》2012,46(7):4074-4082
The electro-Fenton treatment of sulfachloropyridazine (SCP), a model for sulfonamide antibiotics that are widespread in waters, was performed using cells with a carbon-felt cathode and Pt or boron-doped diamond (BDD) anode, aiming to present an integral assessment of the kinetics, electrodegradation byproducts, and toxicity evolution. H(2)O(2) electrogeneration in the presence of Fe(2+) yielded (?)OH in the solution bulk, which acted concomitantly with (?)OH adsorbed at the anode (BDD((?)OH)) to promote the oxidative degradation of SCP (k(abs,SCP) = (1.58 ± 0.02) × 10(9) M(-1) s(-1)) and its byproducts. A detailed scheme for the complete mineralization was elucidated. On the basis of the action of (?)OH onto four different SCP sites, the pathways leading to total decontamination includes fifteen cyclic byproducts identified by HPLC and GC-MS, five aliphatic carboxylic acids, and a mixture of Cl(-), SO(4)(2-), NH(4)(+), and NO(3)(-) that accounted for 90-100% of initial Cl, S, and N. The time course of byproducts was satisfactorily correlated with the toxicity profiles determined from inhibition of Vibrio fischeri luminescence. 3-Amino-6-chloropyridazine and p-benzoquinone were responsible for the increased toxicity during the first stages. Independent electrolyses revealed that their toxicity trends were close to those of SCP. The formation of the carboxylic acids involved a sharp toxicity decrease, thus ensuring overall detoxification. 相似文献
79.
• | Forecasting changes in business environments is critical for appropriate responses by policy makers and corporate decision makers. This article reports on a Delphi study which features three rounds of interchanges between experts on possible changes in the international business environment and practice in the next years. |
• | Results indicate that terrorism and corruption issues have risen in importance while trade negotiations have declined. Corporate strategies are seen to need significant reform to deliver on the promise of globalization. As trends are becoming more multidimensional, regular solicitation of stakeholder perspectives becomes more important. |
80.
David Plackett Harvey Anturi Mikael Hedenqvist Mikael Ankerfors Mikael Gällstedt Tom Lindström István Siró 《应用聚合物科学杂志》2010,117(6):3601-3609
Two types of microfibrillated cellulose (MFC) were prepared using either a sulfite pulp containing a high amount of hemicellulose (MFC 1) or a carboxymethylated dissolving pulp (MFC 2). MFC gels were then combined with amylopectin solutions to produce solvent‐cast MFC‐reinforced amylopectin films. Tensile testing revealed that MFC 2‐reinforced films exhibited a more ductile behavior and that MFC 1‐reinforced films had higher modulus of elasticity (E‐modulus) at MFC loadings of 50 wt % or higher. Pure MFC films had relatively low oxygen permeability values when data were compared with those for a variety of other polymer films. MFC 1 and MFC 2 films had similar opacity but differences in appearance which were attributed to the presence of some larger fibers and nanofiber agglomerates in MFC 2. Field emission scanning electron microscopy (FE‐SEM) and atomic force microscopy (AFM) were used to illustrate the morphology of MFC nanofibers in pure films and in an amylopectin matrix. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献