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排序方式: 共有150条查询结果,搜索用时 78 毫秒
1.
Inherited cardiomyopathies are frequent causes of sudden cardiac death (SCD), especially in young patients. Despite at the autopsy they usually have distinctive microscopic and/or macroscopic diagnostic features, their phenotypes may be mild or ambiguous, possibly leading to misdiagnoses or missed diagnoses. In this review, the main differential diagnoses of hypertrophic cardiomyopathy (e.g., athlete’s heart, idiopathic left ventricular hypertrophy), arrhythmogenic cardiomyopathy (e.g., adipositas cordis, myocarditis) and dilated cardiomyopathy (e.g., acquired forms of dilated cardiomyopathy, left ventricular noncompaction) are discussed. Moreover, the diagnostic issues in SCD victims affected by phenotype-negative hypertrophic cardiomyopathy and the relationship between myocardial bridging and hypertrophic cardiomyopathy are analyzed. Finally, the applications/limits of virtopsy and post-mortem genetic testing in this field are discussed, with particular attention to the issues related to the assessment of the significance of the genetic variants.  相似文献   
2.
Thin-layer carbon supported Nafion-H catalysts were found to be active and highly selective (S>98%) for the partial oxidation of C1-C3 alkanes, in a three phase catalytic membrane reactor (3PCMR), under mild conditions and in the presence of H2O2. The influences of the catalyst teflon loading and H2O2 concentration on the reaction rate have been evaluated. A reaction pathway, based on the electrophilic hydroxylation of the C-H bond of alkanes with protonated hydrogen peroxide (H3O 2 + ), is discussed.  相似文献   
3.
Spherical electrode carbon particles prepared from carbon rods of dry cell batteries have been used to study the attrition behaviour in a bubbling fluidized bed combustor. Experiments have been conducted in a 40 mm I.D. and 1 m high fluidized bed combustor operated at 1 m/s superficial velocity. The bed was operated with nitrogen and with two different oxygen concentrations at 850°C to study the effect of combustion on attrition of these particles. The experimental technique used allowed the time resolution of attrited fines generation, providing detailed curves of attrition rates as a function of time. Attrition rate constants have been evaluated. Results show an enhancement of attrition due to combustion even for spherical, homogeneous and smooth particles.  相似文献   
4.
Synthesis of liquid oxygenates from light alkanes (C1--C3) is achieved in a multifunctional three-phase catalytic membrane reactor (3PCMR) operating under mild conditions (TR, 80-120 °C; PR, 140 kPa). The features of superacid catalytic membranes mediated by the Men+/H2O2 Fenton system in activating C1-C3 alkanes are presented. The effect of operating conditions ([H2O2], [Men+]) on the catalyst activity is outlined. A general reaction pathway accounting for the activation of the CH bond of the alkane molecule on the superacid sites and the subsequent reaction of the activated alkane with primary reactive intermediates, generated from the Men+/H2O2 system, is proposed. The suitability of the 3PCMR in enabling simultaneous reaction and product separation is discussed.  相似文献   
5.
Precipitated silica catalysts loaded with either MoO3 (0.2–4.0 wt%) or V2O5 (0.2–5.3 wt%) have been studied in the selective partial oxidation of methane to formaldehyde with molecular oxygen at 520 °C. The functionality of the SiO2 surface towards the formation of HCHO is significantly promoted by V2O5, while it is depressed by the MoO3.  相似文献   
6.
Design and control of an IPMC wormlike robot.   总被引:2,自引:0,他引:2  
This paper presents an innovative wormlike robot controlled by cellular neural networks (CNNs) and made of an ionic polymer-metal composite (IPMC) self-actuated skeleton. The IPMC actuators, from which it is made of, are new materials that behave similarly to biological muscles. The idea that inspired the work is the possibility of using IPMCs to design autonomous moving structures. CNNs have already demonstrated their powerfulness as new structures for bio-inspired locomotion generation and control. The control scheme for the proposed IPMC moving structure is based on CNNs. The wormlike robot is totally made of IPMCs, and each actuator has to carry its own weight. All the actuators are connected together without using any other additional part, thereby constituting the robot structure itself. Worm locomotion is performed by bending the actuators sequentially from "tail" to "head," imitating the traveling wave observed in real-world undulatory locomotion. The activation signals are generated by a CNN. In the authors' opinion, the proposed strategy represents a promising solution in the field of autonomous and light structures that are capable of reconfiguring and moving in line with spatial-temporal dynamics generated by CNNs.  相似文献   
7.
Uncoupled thermomechanical transient analyses have been carried out to investigate the behavior of IFMIF-EVEDA lithium test loop bayonet backplate target assembly under two selected start-up transient operational scenarios. The first transient scenario considered foresees that the target assembly, starting from the initial uniform temperature of 50 °C, is heated up uniquely by convective heat transfer with lithium, flowing from inlet to outlet nozzle at its reference nominal temperature and pressure, until its nominal steady state thermal field distribution is reached. The second transient scenario foresees, more realistically, that the target assembly, starting from the uniform temperature of 50 °C, is initially warmed-up by electric heaters mounted onto its main accessible surfaces and, subsequently, by convective heat transfer with lithium reference flow, until nominal steady state conditions are reached. Heaters have been supposed to operate in an on/off stepwise mode, resulting to be alternatively switched on and off in order to allow the target assembly thermal field to grow up minimizing thermal gradients. To this purpose, a parametric analysis has been performed to realistically assess, for each electric heater, its heat flux and duty-cycle. Numerical results obtained are presented and critically discussed.  相似文献   
8.
A preparation method of highly effective methane to formaldehyde partial oxidation (MPO) FeOx/SiO2 catalysts (Fe 0.09--0.43 wt%) is reported, based on adsorption-precipitation (ADS/PRC) of FeII ions under controlled conditions. The performance of ADS/PRC catalysts in the MPO reaction at 650 °C has been compared with that of conventional systems prepared by incipient wetness (INC/WET) of silica carriers with aqueous solutions of FeIII. The ADS/PRC method, likely enabling a higher dispersion of the active phase, provides very effective MPO catalysts featuring CH4 turnover frequency (TOF) and HCHO productivity (STYHCHO) values larger than those of the counterpart INC/WET systems.  相似文献   
9.
10.
Organic double layers obtained by electrodeposition of a substituted polythiophene followed by spin-coating of a Tetracyanoquinodimethane (TCNQ) electron acceptor layer, are characterized by means of spectrophotometric measurements carried out in the UV-VIS-IR range. According to the optical data, the electron acceptor molecules reduce to the singly ionized state as a consequence of a charge-transfer reaction that takes place at the interface with the electrodeposited polymer, which acts as an electron donor. Rectifying heterojunctions are obtained by depositing the double layers on the top of monocrystalline silicon wafers, and on the top of monocrystalline silicon wafers coated with electrochemically de-doped poly(3,4-ethylendioxythiophene)/poly(styrenesulfonate) (PEDOT/PSS). Current versus voltage measurements performed in the dark and under halogen light irradiation show that the developed heterojunctions exhibit photosensitive charge transport features, promising in view of photovoltaic applications.  相似文献   
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