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31.
The properties of a material can be engineered by manipulating its atomic and chemical architecture. Nanoglasses which have been recently invented and comprise nanosized glassy particles separated by amorphous interfaces, have shown promising properties. A potential way to exploit the structural benefits of nanoglasses and of nanocrystalline materials is to optimize the composition to obtain crystals forming within the glassy particles. Here, a metastable Fe‐10 at% Sc nanoglass is synthesized. A complex hierarchical microstructure is evidenced experimentally at the atomic scale. This bulk material comprises grains of a Fe90Sc10 amorphous matrix separated by an amorphous interfacial network enriched and likely stabilized by hydrogen, and property‐enhancing pure‐Fe nanocrystals self‐assembled within the matrix. This composite structure leads a yield strength above 2.5 GPa with an exceptional quasi‐homogeneous plastic flow of more than 60% in compression. This work opens new pathways to design materials with even superior properties.  相似文献   
32.

Relying on the past technology radio reception through hardware needs front end tuning which in turn internally changes the frequency of the capacitor. Thus the conventional radio can capture the required frequency by tuning manually. As the technology advances the wireless technology shown the light of cognition through which real time data transmission and reception are implemented using reconfigurable radio i.e., Software Defined Radio (SDR) whose physical layer functions are mainly or fully defined by software. In this paper, HackRFOne (Software defined Radio SDR) is tuned to the required radio frequency by employing GNU Radio Companion and Gqrx (spectrum viewer), where both GNU Radio and Gqrx are an open ended software. Cognitive Radio have revealed that by varying the software, the hardware adjustment is possible only within a fraction of the time. However, this requires more knowledge on signal processing blocks so that adjusting certain parameters like gain and frequency of filter can be made in the receiver side. The goal of this paper is to focus on the signal processing blocks which plays vital role in implementing the transmitter / receiver for reconfigurable wireless communication system.

  相似文献   
33.
Microsystem Technologies - Wireless sensor networks (WSN) are primarily used for sensing and collecting the information from environment. This information is sent to base station (BS), where, it is...  相似文献   
34.
In vivo imaging of hydrogen peroxide with chemiluminescent nanoparticles   总被引:1,自引:0,他引:1  
The overproduction of hydrogen peroxide is implicated in the development of numerous diseases and there is currently great interest in developing contrast agents that can image hydrogen peroxide in vivo. In this report, we demonstrate that nanoparticles formulated from peroxalate esters and fluorescent dyes can image hydrogen peroxide in vivo with high specificity and sensitivity. The peroxalate nanoparticles image hydrogen peroxide by undergoing a three-component chemiluminescent reaction between hydrogen peroxide, peroxalate esters and fluorescent dyes. The peroxalate nanoparticles have several attractive properties for in vivo imaging, such as tunable wavelength emission (460-630 nm), nanomolar sensitivity for hydrogen peroxide and excellent specificity for hydrogen peroxide over other reactive oxygen species. The peroxalate nanoparticles were capable of imaging hydrogen peroxide in the peritoneal cavity of mice during a lipopolysaccharide-induced inflammatory response. We anticipate numerous applications of peroxalate nanoparticles for in vivo imaging of hydrogen peroxide, given their high specificity and sensitivity and deep-tissue-imaging capability.  相似文献   
35.
Freshly harvested Jatropha dried fruit contains about 35–40% shell and 60–65% seed (by weight). The fruits are 2.5 cm long, ovoid, black and have 2–3 halves. It has nearly 400–425 fruits per kg and 1580–1600 seed per kg weight. Weight of 100 seeds is about 63 g. Jatropha shells are available after de-shelling of the Jatropha fruit while Jatropha seed husks are available after decortications of Jatropha seed for oil extraction. Seed contains about 40–42% husk/hull and 58–60% kernels. The kernels have about 50% oil. If the oil is extracted by solvent method the oil recovery is more than 95% but in mechanical expeller the oil recovery is about 85% only. If 100 kg of seed is expelled by expeller it will give about 28–30 kg oil. While lot of emphasis is being given on use of bio-diesel, which is only about 17–18% of the dry fruit, not much attention is being given to utilize other components of fruit for energy purposes.At SPRERI holistic approach has been taken to utilize all components of the Jatropha fruit—shell for combustion, hull/husk for gasification, oil and bio-diesel for running CI engines, cake for production of biogas and spent slurry as manure and it has been found that all components of the Jatropha curcas fruit can be utilized efficiently for energy purposes. This paper gives detailed information on the use of different components of J. curcas fruit for energy purposes.  相似文献   
36.
This paper presents the tensile response of thin-walled composite tubes with multi-axial fibre architecture. A hybrid braid-wound layup has the potential to optimise the composite tube properties, however, stacking sequence plays a role in the failure mechanism. A braid-winding method has been used to produce stacked overwound braid layup [(±45°/0°)5/90°4]T. Influence of stacking sequence on premature failure of hoop layers has been reported. Under tensile loading, a cross-ply composite tube with the alternate stacking of hoop and axial fibre show hoop plies splitting similar to the overwound braided composite tube. However, splitting has been restricted by the surrounding axial plies and contained between the adjacent axial fibre tows. This observation suggests hoop layers sandwiched between braid layers will improve structural integrity. A near net shape architecture with three fibre orientation in a triaxial braid will provide additional support to prevent extensive damage for plies loaded in off-axis. Several notable observations for relatively open braid structures such as tow scissoring, high Poisson’s ratio and influence of axial tow crimp on the strain to failure have been reported. Digital Image Correlation (DIC) in conjunction with surface strain gauging has been employed to capture the strain pattern.  相似文献   
37.
Use of cysteamine hydrochloride (Cys-HCl) protected gold nanorods (GNRs) as efficient carrier of widely used anti-cancer drug doxorubicin using folic acid as navigational molecule is presented in this work. GNRs were found to have excellent drug loading capacity of >97 %. A detailed comprehension of in vitro drug release profile under ideal physiological condition was found to obey 1st order kinetics at pH 6.8, 5.3 and 7.2, an ideal milieu for drug delivery to solid tumours.  相似文献   
38.
To improve its dissolution, ibuprofen solid dispersions (SDs) were prepared in a relatively easy and simple manner, characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR), and evaluated for solubility and in vitro drug release. Loss of individual surface properties during melting and re-solidification as revealed by SEM micrographs indicated the formation of effective SDs. Absence or shifting toward the lower melting temperature of the drug peak in SDs in DSC study indicated the possibilities of drug–polymer interactions. FTIR spectra showed the presence of drug crystalline in SDs. The effect of improved dissolution on the oral absorption of ibuprofen in rats was also studied. Quicker release of ibuprofen from SDs in rat intestine resulted in a significant increase in AUC and Cmax, and a significant decrease in Tmax over pure ibuprofen. Preliminary results from this study suggested that the preparation of fast dissolving ibuprofen SDs by low-temperature melting method using polyethylene glycol 20000 as a meltable hydrophilic polymer carrier could be a promising approach to improve solubility, dissolution, and absorption rate of ibuprofen.  相似文献   
39.
Journal of Materials Science: Materials in Electronics - The present work accentuates the aspects of electrochemical analysis determined by cyclic voltammeter (CV), especially enhancement in...  相似文献   
40.
Thakur M  Tay CJ  Quan C 《Applied optics》2005,44(13):2541-2545
Talbot interferometry is used to study the surface profile of a transparent object. Periodic patterns are produced by illuminating a grating with a collimated laser beam. The object is placed on the self-image plane of the grating. The deformed grating image, which interferes with another grating, results in the Talbot interferometric fringes. The fringe pattern is recorded on a CCD camera for subsequent analysis, and the phase variation is achieved by a linear translation stage. In this application two specimens are tested to demonstrate the validity of the method; one is a transparent object with a spherical shape with a height of less than 350 microm, and the other is a transparent object with an uneven surface of 50-microm average height. The experimental results are compared with the test results obtained with the mechanical stylus method.  相似文献   
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