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51.
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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   
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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   
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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   
55.
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   
56.
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   
57.
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   
58.
The development of a new kind of material that is a nanostructured catalytic material with an environmentally benign nature that can be used for alternative energy has acquired significance in recent years. In this context, the use of heterogeneous catalysts for the transesterification of vegetable oils has gained prominence due to their eco‐friendly and reusable nature. Hence in the present study, pure hydroxyapatite (HAp) and hydroxyapatite/platinum (HAp/Pt) nanostructured particles have been prepared successfully through a facile chemical method without templates and surfactants and their catalytic activity investigated for transesterification of natural vegetable oil to bioenergy (biodiesel). The textural and structural features of pure HAp and HAp/Pt were investigated using various characterization techniques such as x‐ray diffraction, Fourier transform infrared (FTIR) and Raman spectroscopy, field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The elements present in the prepared nanostructures were confirmed through energy dispersive spectroscopy (EDS) and x‐ray photoelectron spectroscopy (XPS) techniques. The XPS analysis also confirms the metallic nature of the platinum in HAp/Pt. The specific surface area and porous nature of the prepared nanostructured catalysts were studied using the N2 physisorption Brunauer‐Emmett‐Teller‐Barrett‐Joyner‐Halenda (BET‐BJH) method. The catalytic activity of the pure HAp nanoparticles and HAp/Pt core shell nanorods with the Simarouba glauca plant seed oil was investigated. The obtained results indicate that the pristine HAp nanoparticles and HAp/Pt core shell nanorods (NRs) show 91.4% and 87.1% fatty acid methyl ester (FAME) conversion, respectively, potentially offering environmental benign biocatalysts for biofuel production from natural feed stock.  相似文献   
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60.
In today's business transactions, there are various reasons, namely, bulk purchase discounts, re-ordering costs, seasonality of products, inflation induced demand, etc., which force the buyer to order more than the warehouse capacity. Such situations call for additional storage space to store the excess units purchased. This additional storage space is typically a rented warehouse. Inflation plays a very interesting and significant role here: It increases the cost of goods. To safeguard from the rising prices, during the inflation regime, the organisation prefers to keep a higher inventory, thereby increasing the aggregate demand. This additional inventory needs additional storage space, which is facilitated by a rented warehouse. Ignoring the effects of the time value of money and inflation might yield misleading results. In this study, a two-warehouse inventory model with linear trend in demand under inflationary conditions having different rates of deterioration has been developed. Shortages at the owned warehouse are also allowed subject to partial backlogging. The solution methodology provided in the model helps to decide on the feasibility of renting a warehouse. Finally, findings have been illustrated with the help of numerical examples. Comprehensive sensitivity analysis has also been provided.  相似文献   
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