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51.
The paper proposes an energy efficient quality of services (QoS) aware hierarchical KF-MAC routing protocol in mobile ad-hoc networks. The proposed KF-MAC (K-means cluster formation firefly cluster head selection based MAC routing) protocol reduces the concentration of QoS parameters when the node transmits data from source to destination. At first, K-means clustering technique is utilized for clustering the network into nodes. Then the clustered nodes are classified and optimized by the firefly optimization algorithm to find cluster heads for the clustered nodes. The transmission of data begins in the network nodes and TDMA based MAC routing does communication. The observation on KF-MAC protocol performs well for QoS parameters such as bandwidth, delay, bit error rate and jitter. The evaluation of proposed protocol based on a simulation study concludes that the proposed protocol provides a better result in contrast to the existing fuzzy based energy aware routing protocol and modified dynamic source routing protocol. With KF-MAC protocol, the collision free data transmission with low average energy consumption is achieved.  相似文献   
52.
Social Internet of Things (SIoT) is a young paradigm that integrates Internet of Things and Social Networks. Social Internet of Things is defined as a social network of intelligent objects. SIoT has led to autonomous decision making and communication between object peers. SIoT has created and opened many research avenues in the recent years and it is vital to understand the impact of SIoT in the real world. In this paper, we have mined twitter to evaluate the user awareness and impact of SIoT among the public. We use R for mining twitter and perform extensive sentiment analysis using supervised and semi supervised algorithms to evaluate the user’s perception about SIoT. Experimental results show that the proposed Fragment Vector model, a semi supervised classification algorithm is better when compared to supervised classification algorithms namely Improved Polarity Classifier (IPC) and SentiWordNet Classifier (SWNC). We also evaluate the combined performance of IPC and SWNC and propose a hybrid classifier (IPC?+?SWNC). Our analysis was challenged by limited number of tweets with respect to our study. Experimental results using R has produced evidences of its social influences.  相似文献   
53.
The effect of Ag addition on weak link behaviour of a Bi-2223 (Bi1.7Pb0.3Sr2Ca2Cu3O10) polycrystalline sample has been investigated in terms of AC susceptibility, critical current density (J c), electrical resistivity ρ(T)H and upper critical field (H c2). A series of phase pure Bi-2223-Ag x (x = 0.0–0.3) samples are prepared by the solid-state synthesis route. The phase purity, crystal structures and surface morphology are being studied using the X-ray diffraction and scanning electron microscopy (SEM) technique, respectively. The effect of Ag addition on inter- and intragranular coupling has been investigated by means of AC susceptibility and magneto-transport ρ(T)H measurements, and the results are compared with the pure Bi-2223 sample. Enhancement in granular coupling between the grains of the 20 wt% Ag-added Bi-2223 sample has been witnessed. Critical current density (J c) has been estimated using the AC susceptibility technique, and the results are interpreted in terms of inter- and intragranular coupling of the investigated samples. The high field magneto-transport technique has been used to estimate the upper critical field (H c2) and thermally activation flux flow (TAFF) activation energy. The ensuing results revealed that H c2 increases for the 20 wt% Ag-added sample along with enhancement in grain alignment and intergrain connectivity.  相似文献   
54.
Nano-particle Co1?x Zn x Fe2O4 (x = 0.0, 0.3, 0.5, 0.7, and 1.0) samples were prepared via combustion route using Alove Vera Gel. XRD, IR, and SAED analysis represents single-phase formation of ferrite samples, and nano-sizes of the particles in the range of 6 to 13 nm were confirmed using XRD data and TEM images. Decrease in lattice constant with increasing Zn content reflects formation of compositionally homogeneous samples. Dielectric constant and dielectric loss study showed promising results. The room temperature Mossbauer spectrum showed mixed superparamagnetic and ordered ferromagnetic behavior. The possible modification in the cation distributions was seen in the nano-particle ZnFe2O4 sample obtained in the present work compared to conventional bulk samples.  相似文献   
55.
Multimedia Tools and Applications - Medical image is the visual representation of anatomy or physiology of internal structures of the body and it is useful for clinical analysis and medical...  相似文献   
56.
Anodic bonding of Pyrex 7740 glass to bare silicon and oxidized silicon wafer is presented for micro electro mechanical systems (MEMS) device packaging. Experimentally it has been observed that anodic bonding process parameters are varying with different 3D structures. The effects of bonding temperature and voltage are discussed by keeping the temperature constant and varying the voltage. The bonding interface has been studied by scanning electron microscope observations. Effective parameters for MEMS structure such as bonding temperature, voltage has been discussed.  相似文献   
57.
This research deals with the facile combustion synthesis of manganese ferrite (MFO) nanoparticle with different cerium concentration and their potential application as an efficient photocatalyst and chemical sensor. The concentration of introduced cerium affects the size, structure, compositional, morphological, optical, photoluminescence and magnetic properties of the ferrite nanoparticle. The X-ray diffraction pattern affirmed the arrangement of cubic spinel structure with the formation of secondary phase CeO2 as the cerium concentration exceed 3 mol%. SEM micrographs revealed irregular morphology with more number of pores and voids. HRTEM along with SAED pattern revealed the crystalline cubic nature. The optical band gap deduced from UV–Vis-DRS spectra was observed to be in the range 2.3–2.8 eV. PL studies indicated a significant minimization in combination of electrons & holes in MnFe2O4 on addition of Ce dopant. VSM investigation demonstrated the soft magnetic nature of the prepared sample with moderate magnetization value. An excellent photocatalytic performance of Cerium doped MFO (3 mol%) towards MB and AR dye degradation was found to be 1.5 and 1.67 times more compared to host matrix under Sunlight irradiation that correlated to reduced band gap, Ce dopant and efficient separation of charge carriers. Cerium doped MFO (3 mol%) have high specific capacitance value of 471.7 and 1546.8 Fg-1 for NaNO3 and HCl electrolytes respectively, indicating the pseudo capacitance nature due to which it can be used as a supercapacitor. The synthesized nanoparticles can sense d-Glucose and Paracetamol even at a lower concentration varying from 1 to 10 mM. The synthesized Ce-doped MnFe2O4 nanomaterials have great potential to be used in the future production of promising active photocatalysts and sensitive chemical sensors for the identification and degradation of toxic industrial dyes for improved safety in the fields of environment and health care.  相似文献   
58.
The relative Influence of nine techniques for drying wet granulated microcrystal-lline cellulose (MCC) on the subsequent compaction characteristics was studied In terms of the tensile strength and corrected work of failure of the tablets. Wet granulation resulted in a substantial decrease in compatibility. However, the drying technique used was found to affect the degree of loss in compatibility. In general, microwave-vacuum drying using the “high” process type resulted in the production of granules with the highest compatibility followed by freeze drying and fluidized bed drying. Granules dried under ambient conditions, and granules tray dried to “just dry” or “over dried” conditions resulted In tablets possessing approximately comparable compatibilites, with the poorest compaction characteristics being exhibited by vacuum dried granules, in addition It was found that use of a “low” drying process type during microwave- vacuum drying yielded granules with inferior compaction characteristics to those dried by the “high” process type. Radio frequency drying was found to yield granules which produced tablets having slightly inferior tensile strength to tray dried material, although the tablet work of failure values were comparable. The effect of drying technique on the subsequent compaction characteristics was not found to be directly related to the moisture content of the granules.  相似文献   
59.
Plants have evolved several adaptive strategies through physiological changes in response to herbivore attacks. Plant secondary metabolites (PSMs) are synthesized to provide defensive functions and regulate defense signaling pathways to safeguard plants against herbivores. Herbivore injury initiates complex reactions which ultimately lead to synthesis and accumulation of PSMs. The biosynthesis of these metabolites is regulated by the interplay of signaling molecules comprising phytohormones. Plant volatile metabolites are released upon herbivore attack and are capable of directly inducing or priming hormonal defense signaling pathways. Secondary metabolites enable plants to quickly detect herbivore attacks and respond in a timely way in a rapidly changing scenario of pest and environment. Several studies have suggested that the potential for adaptation and/or resistance by insect herbivores to secondary metabolites is limited. These metabolites cause direct toxicity to insect pests, stimulate antixenosis mechanisms in plants to insect herbivores, and, by recruiting herbivore natural enemies, indirectly protect the plants. Herbivores adapt to secondary metabolites by the up/down regulation of sensory genes, and sequestration or detoxification of toxic metabolites. PSMs modulate multi-trophic interactions involving host plants, herbivores, natural enemies and pollinators. Although the role of secondary metabolites in plant-pollinator interplay has been little explored, several reports suggest that both plants and pollinators are mutually benefited. Molecular insights into the regulatory proteins and genes involved in the biosynthesis of secondary metabolites will pave the way for the metabolic engineering of biosynthetic pathway intermediates for improving plant tolerance to herbivores. This review throws light on the role of PSMs in modulating multi-trophic interactions, contributing to the knowledge of plant-herbivore interactions to enable their management in an eco-friendly and sustainable manner.  相似文献   
60.
Nuclear energy generation technology is critically linked with the safe disposal of radioactive waste. In this context, iron phosphate glass (IPG) is gaining predominance as nuclear waste vitrification matrix that necessitates a thorough study on the effect of the loading of various nuclear fission waste materials in it. In this study, the effect of the loading of Nd3+ (which acts as a surrogate for radioactive curium (Cm)) and Ru4+ (which is a fission product of 235U) in IPG has been assessed. The optimum loading of Nd3+/Ru4+ leading to the formation of homogenous melt has been ascertained via powder X-ray diffraction and scanning electron microscopy techniques. The modification in the Fe3+/Fe2+ ratio in IPG and the consequent change in its average coordination number with Nd3+/Ru4+ loading has been deduced from the Mössbauer studies. Local structure analysis has been done using X-ray absorption spectroscopy at Nd/Ru/Fe K-edge (as applicable) for all the single and co-loaded IPG samples. All the co-loaded samples show enhanced glass stability and glass forming ability compared to unloaded IPG which has been ascertained via detailed thermal studies. The variation in IPG network structure on the addition of Nd2O3 and RuO2 has been ascertained through spectroscopic techniques like Fourier transform infrared (FTIR) and Raman. The base glass and a few representative homogenous single and co-loaded IPG samples have been irradiated with 4.5 MeV proton beam to simulate the hosting of radioactive elements and the radiation effect on glass structure has been ascertained using FTIR and Raman spectroscopies. The suitability of IPG as nuclear waste vitrification matrix for Nd3+ and Ru4+ is established through all the above analyses.  相似文献   
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