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31.
Food Science and Biotechnology - Acrylamide and 5-hydroxymethylfurfural (HMF) is the product of the Maillard reaction and its accumulation may lead to adverse health effects. Hence, this paper aims...  相似文献   
32.
A process of making a symmetrical self-aligned n-type vertical double-gate MOSFET (n-VDGM) over a silicon pillar is revealed. This process utilizes the technique of oblique rotating ion implantation (ORI). The self-aligned region forms a sharp vertical channel profile and decreases the channel length Lg. A tremendous improvement in the drive-on current is noted. The electron concentration profile obtained demonstrates an increased number of electrons in the channel injected from the source end as the drain voltage increases. The enhanced carrier concentration results in significant reduction in the off-state leakage current and improves the drain-induced barrier-lowering (DIBL) effect. These simulated characteristics when compared to those in a fabricated device without the ORI method show the distinct advantage of the technique reported for suppression of short-channel effects (SCE) in nanoscale vertical MOSFET.  相似文献   
33.
Hydrogel dressings should be adhesive and elastic, while providing excellent functional and aesthetic features. Owing to weak intermolecular forces, various measures are undertaken to improve the hydrogel mechanical properties. Thermo-responsive poly(2-(2-methoxyethoxy)ethyl methacrylate) (poly(MEO2MA)) hydrogel fabricated with different amounts of di(ethylene glycol) dimethacrylate (DEGDMA) cross-linker was characterised using texture profile analysis. More cross-linking sites incorporated within the hydrogel limit the swelling ability where 1.0 and 10?mol-% of DEGDMA swell by 8.03 and 1.92 times, at 5°C. Hydrogel textural and tensile property correlated with the cross-linker amount. Meanwhile, network structure disentanglement within swollen hydrogel reduced the force required for deformation. Thus, the swelling behaviour, textural and tensile properties were investigated to discern the possible biomedical applications suitable for this hydrogel.  相似文献   
34.
A series of mesoporous silicas (MS-1–MS-9) were synthesized at different gel compositions using a triblock copolymer (TCP), poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide), as the surfactant. The interactive effects of acidity, the contents of tetraethyl orthosilicate (TEOS) and the surfactant, and the gelling temperature on the characteristics of the final material were simultaneously characterized. Increasing acidity favored mesopore formation. A material with a surface area of 760 m2/g, mostly in the mesoporous range, was obtained at 1.0(TEOS):0.017(TCP):7.3HCl:115.7H2O. Mesopore formation was predominantly determined by the TEOS:TCP ratio and was promoted with its increase from 1.56:1 to 2.09:1. A further increase to 2.61:1 was detrimental. Whereas increasing the TCP content to 3.5% w/w improved micellization, a further increase to 4.6% should be avoided. Mesoporous silicas showed low crystallinity but a high degree of hexagonal mesoscopic organization. The weak surface acidity was attributed to surface silanols, the number of which was proportional to mesoporosity.  相似文献   
35.
A new model for threshold voltage of double-gate Bilayer Graphene Field Effect Transistors (BLG-FETs) is presented in this paper. The modeling starts with deriving surface potential and the threshold voltage was modeled by calculating the minimum surface potential along the channel. The effect of quantum capacitance was taken into account in the potential distribution model. For the purpose of verification, FlexPDE 3D Poisson solver was employed. Comparison of theoretical and simulation results shows a good agreement. Using the proposed model, the effect of several structural parameters i.e. oxide thickness, quantum capacitance, drain voltage, channel length and doping concentration on the threshold voltage and surface potential was comprehensively studied.  相似文献   
36.
One of the most compatible coatings, known as yttria-stabilised zirconia polycrystal (YZP) is deposited on metallic Ti alloys due to its excellent hardness and aesthetic value as well as its low affinity for plaques. However, poor bioactivities of YZP and the existence of micro crack propagations due to the aging of YZP may result in spontaneous implant failure thus limiting its clinical use. In this work, YZP coating reinforced titania (TiO2), which is formed via a plasma spray technique was investigated in order to enhance the bioactivity and the mechanical properties of YZP coatings for dental implants. Based on microstructural studies performed on the deposited coating, a distinguished lamellar structure comprising YZP and TiO2 was observed. It was found that the reinforcement of TiO2 in YZP coating significantly reduced the crack due to the improved densities and the lamellar structure. The mechanical properties were also found to improve with 90% of hardness, 45% of adhesion strength and 54% of Young's Modulus with TiO2 addition, which is desirable for dental implants. An in-vitro bioactivity test was then conducted by immersing the coatings in a simulated body fluid (SBF). As a result, an apatite formation was found on the YZP/TiO2 coating surface after 3 days of immersion. Besides, it was verified in an XRD analysis that the crystalline TiO2 was found in a rutile phase which was highly effective in generating apatite (natural mineral in human bones) on YZP coatings, proving that the bioactivities of the coating were significantly improved. Further studies were also performed on the SBF treatment, which took up to 14 days also demonstrated that only a small decrease in hardness was noted, indicating that YZP/TiO2 coatings had reached an excellent mechanical stability.  相似文献   
37.
NiTi shape memory alloy archwire is widely used in orthodontic treatment, replacing stainless steel for the flat and low deactivation force it can offer. However, the presence of friction at the contact region of wire and bracket may cause the low deactivation force to be ineffective to induce tooth movement. This work evaluated the bending deformation behavior of NiTi archwire in application using conventional orthodontic stainless steel bracket in levelling treatment. Experimental test rig was developed to perform three-brackets bending test at room temperatures (27 °C). The bracket used was 0.022-in stainless steel and the archwire was 0.016-in NiTi round wire. Fabricated polytetrafluoroethylene (Teflon) bracket was used as a control experiment to represent frictionless condition of deformation on three-bracket bending. Additionally, elastomeric ligature was also used to evaluate the effect of friction produced by the elastomer. Bending tests were done at 3 different deflection magnitudes of 2 mm, 3 mm and 4 mm. The results show that bending deformation behavior of the wire on frictionless Teflon bracket produced a flat force plateau on both activation and deactivation. On the other hand, when stainless steel brackets were used, the force plateau exhibited positive gradient on the activation and negative gradient on the deactivation.  相似文献   
38.
In this paper, the techniques for the synthesis of CaFe2O4 nanoparticles using the auto-combustion and co-precipitation methods are discussed. The effects of both methods on the microstructure and magnetic properties of the CaFe2O4 nanoparticles were compared. The CaFe2O4 powder was obtained after drying the synthesized sample via co-precipitation overnight in an oven at 80 °C. For auto-combustion method, the sol that was initially formed was gradually converted into a gel, which was then combusted at 250 °C. Finally, the CaFe2O4 nanoparticles were calcined at 550 °C. The different synthesis methods produced nanoparticles with different physical and magnetic properties in order to find an optimum size to be utilized for drug delivery applications. The results of the X-ray diffraction showed that both processes produced nanocrystals with an orthorhombic crystalline structure. It was noted from the measurements made with a transmission electron microscope (TEM) that the synthesis using the co-precipitation method produced nanoparticles with a size of about 10–20 nm, which was comparable with the size that was obtained when the auto-combustion method was used. The magnetic properties were investigated using a vibrating sample magnetometer (VSM), where the magnetic saturation (Ms) of CaFe2O4 for the sample synthesized using the co-precipitation method was 47.279 emu/g, which was higher than the magnetic saturation (Ms) of 31.10 emu/g obtained when the auto-combustion method was used. The hysteresis loops (Hc) for the samples were 17.380 G and 6.1672 G, respectively. Additionally, the elaborate properties mentioned above, such as the size and superparamagnetic properties of the synthesized CaFe2O4 nanoparticle size, were the characteristics required for drug delivery because the targeted therapy required nanoparticles with good magnetic properties, a suitable size, and which were non-toxic in order to have a potential application in targeted drug delivery systems.  相似文献   
39.
Recent development of trilayer graphene nanoribbon Schottky-barrier field-effect transistors (FETs) will be governed by transistor electrostatics and quantum effects that impose scaling limits like those of Si metal-oxide-semiconductor field-effect transistors. The current–voltage characteristic of a Schottky-barrier FET has been studied as a function of physical parameters such as effective mass, graphene nanoribbon length, gate insulator thickness, and electrical parameters such as Schottky barrier height and applied bias voltage. In this paper, the scaling behaviors of a Schottky-barrier FET using trilayer graphene nanoribbon are studied and analytically modeled. A novel analytical method is also presented for describing a switch in a Schottky-contact double-gate trilayer graphene nanoribbon FET. In the proposed model, different stacking arrangements of trilayer graphene nanoribbon are assumed as metal and semiconductor contacts to form a Schottky transistor. Based on this assumption, an analytical model and numerical solution of the junction current–voltage are presented in which the applied bias voltage and channel length dependence characteristics are highlighted. The model is then compared with other types of transistors. The developed model can assist in comprehending experiments involving graphene nanoribbon Schottky-barrier FETs. It is demonstrated that the proposed structure exhibits negligible short-channel effects, an improved on-current, realistic threshold voltage, and opposite subthreshold slope and meets the International Technology Roadmap for Semiconductors near-term guidelines. Finally, the results showed that there is a fast transient between on-off states. In other words, the suggested model can be used as a high-speed switch where the value of subthreshold slope is small and thus leads to less power consumption.  相似文献   
40.
Multimedia Tools and Applications - Nowadays, visual recognition based dynamic hand gesture tracking has gained very considerable attention. Hand gestures can play an important role as a...  相似文献   
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