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排序方式: 共有514条查询结果,搜索用时 15 毫秒
91.
M. YasinA. Asghar F.M. AnjumM.S. Butt M.I. KhanM.S. Arshad M. ShahidA.H. El-Ghorab T. Shibamoto 《Food chemistry》2012,131(3):768-773
Depression of meat quality is known to be caused by lipid peroxidation occurring in meat. Supplementation of antioxidants in feed decreases lipid peroxidation and improves the oxidative stability of meat after slaughtering. The present study demonstrated that meat obtained from broiler birds fed feed supplemented with α-tocopherol acetate (200 mg/kg feed) along with α-lipoic acid (25, 75, or 150 mg/kg feed) exhibited increased oxidative stability and reduced fat content. The total phenolic content and α-lipoic acid content increased in the meat as the concentration of α-lipoic acid supplementation increased. The protein content in the meat was not changed by the supplementation of α-lipoic acid and α-tocopherol acetate. The results of DPPH and TBA assays demonstrated that feed supplemented with α-lipoic acid and α-tocopherol acetate also enhanced the antioxidant activity of broiler meat. On the other hand, the meat from broiler birds fed feed supplemented with oxidised oil (4% in feed) reduced its oxidative stability. 相似文献
92.
Wastewater treatment by adsorption with electrochemical regeneration using graphite-based adsorbents
H.?M.?A.?Asghar E.?P.?L.?RobertsEmail author S.?N.?Hussain A.?K.?Campen N.?W.?Brown 《Journal of Applied Electrochemistry》2012,42(9):797-807
An innovative technology for wastewater treatment using adsorption and electrochemical regeneration has been developed at the University of Manchester. The process uses a low capacity graphitic adsorbent material (a graphite intercalation compound, NyexTM 1000) which can be regenerated electrochemically. In this study, we investigate the characteristics of a new, partially porous adsorbent material, NyexTM 2000 which offers increased surface area in comparison with NyexTM 1000. NyexTM 2000 was found to have an adsorption capacity of almost three times that of NyexTM 1000. The electrical conductivity of a NyexTM 2000 was found to be double that of NyexTM 1000, enabling improvements in the electrochemical regeneration characteristics. The removal of an anionic azo dye, acid violet 17, from aqueous solution using NyexTM 1000 and 2000 was investigated under various operating conditions. The adsorption of acid violet 17 on NyexTM 2000 was found to be comparatively fast with 75 % of the equilibrium capacity being achieved within 5 min. The parameters affecting the regeneration efficiency including the charge passed, current density, treatment time, adsorbent bed thickness, and pH were investigated. An electrochemical regeneration efficiency of around 100 % was achieved for a fully loaded NyexTM 2000 in a sequential batch electrochemical cell with a regeneration time of 60 min and a charge passed of 100 C g−1 at a current density of 14 mA cm−2. The charge required for electrochemical regeneration was found to be approximately equal to theoretical charge required for complete oxidation of the adsorbed acid violet 17, making process design relatively simple. NyexTM 2000 was found to be an economic adsorbent with relatively small electrical energy consumption required (31 J mg−1 of acid violet 17 treated, compared to 52 J mg−1 of acid violet 17 for NyexTM 1000). Multiple adsorption/regeneration cycles presented no loss in adsorptive capacity and material loses over five adsorption/regeneration cycles. 相似文献
93.
Ali Asghar J Ian Gray Alden M. Booren E A Gomaa Mohamed M Abouzied Elwyn R Miller D Joseph Buckley 《Journal of the science of food and agriculture》1991,57(1):31-41
The influence of three levels of vitamin E in the diet of pigs on the subcellular deposition of α-tocopherol in the muscle and on selected quality characteristics of pork meat (oxidative stability of lipids, colour, drip loss, microbial growth) was studied. The content of α-tocopherol in adipose tissue and L. dorsi muscle as well as in mitochondrial and microsomal fractions of the muscle significantly increased (P < 0.05) with increasing levels of dietary vitamin E. The differences in the concentrations of α-tocopherol in the subcellular fractions were evident in the enhanced stability of the membranes when exposed to metmyoglobin/hydrogen peroxide. The beneficial effect of dietary vitamin E on the oxidative stability of pork lipids during the storage of pork chops and ground pork was also demonstrated. Even though lipid oxidation increased in all cases during storage, the pork products from the pigs receiving the highest level of vitamin E (200 IU kg?1 feed) exhibited the smallest increase in thiobarbituric acid reactive substances. In addition, increased colour stability and decreased drip loss were observed on keeping pork chops, which had been previously frozen for three months, at 4°C under fluoresent light for 10 days. The possible effect of α-tocopherol on membrane fluidity in this context is discussed. 相似文献
94.
Polygerinos P Ataollahi A Schaeffter T Razavi R Seneviratne LD Althoefer K 《IEEE transactions on bio-medical engineering》2011,58(3):721-726
This paper presents a novel, magnetic resonance imaging (MRI)-compatible, force sensor suitable for cardiac catheterization procedures. The miniature, fiber-optic sensor is integrated with the tip of a catheter to allow the detection of interaction forces with the cardiac walls. The optical fiber light intensity is modulated when a force acting at the catheter tip deforms an elastic element, which, in turn, varies the distance between a reflector and the optical fiber. The tip sensor has an external diameter of 9 Fr (3?mm) and can be used during cardiac catheterization procedures. The sensor is able to measure forces in the range of 0-0.85?N, with relatively small hysteresis. A nonlinear method for calibration is used and real-time MRI in vivo experiments are carried out, to prove the feasibility of this low-cost sensor, enabling the detection of catheter-tip contact forces under dynamic conditions. 相似文献
95.
Kati Miettunen Minna Toivola Ghufran Hashmi Jyri Salpakari Imran Asghar Peter Lund 《Carbon》2011,(2):528-532
Carbon gel catalyst layers were used in dye solar cells. These layers were prepared on flexible plastic substrates at low temperatures (130 °C). The carbon gel, demonstrated excellent flexibility which is an important feature for roll-to-roll production and special applications of dye solar cells. The use of these low cost and highly flexible catalyst layers resulted in good photovoltaic performance; only 10% lower than dye solar cells with rigid glass-based counter electrodes prepared with thermal platinization at ∼400 °C temperature. 相似文献
96.
Shabnam Ashhari Ali Asghar Sarabi Seyed Mahmoud Kasiriha Davood Zaarei 《应用聚合物科学杂志》2011,119(1):523-529
Polyurethane (PU)–clay nanocomposite coatings were prepared by a sonication method. The stability and morphology of these coatings was characterized by turbidometry, X‐ray diffraction, and transmission electron microscopy. The anticorrosive properties of these coatings were investigated by salt‐spray and electrochemical impedance spectroscopy methods. According to the results, dispersed nanoclay layers in the matrix of the nanocomposite coating compositions led to superior anticorrosive characteristics compared to those of pure PU coatings. The best results were obtained with coatings containing about 5 wt % clay. The resistance of the coating containing 5% clay was about 9.002 GΩ after 225 days of immersion in a 3.5 wt % NaCl solution, whereas it was only 97 kΩ for the pure PU coating. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
97.
Asghar Mirzazadeh Ghanadi Amir Heydari Nasab Dariush Bastani Ali Akbar Seife Kordi 《Chemical Engineering Communications》2013,200(5):600-605
This article investigates the effect of nanoparticles on mass transfer in the liquid–liquid extraction for the chemical system of n-butanol–succinic acid–water. For this purpose, nanofluids containing various concentrations of ZnO, carbon nanotubes (CNT), and TiO2 nanoparticles in water, as base fluid, were prepared. To examine the flow mode effect on mass transfer rate, different fluid modes including dropping and jetting were employed in the process. Results show that mass transfer rate enhancement depends on the kinds and the concentration of nanoparticles and the modes of flow. It was observed that after adding nanoparticles, the mass transfer rate significantly increases up to two-fold for ZnO nanoparticles. Furthermore, the results indicate that under the circumstances in which the mass flow rate is high enough, the effect of nanoparticles on the mass transfer phenomenon is too slight. 相似文献
98.
Erick González-Rodríguez Holger Maune Yuliang Zheng Mohsen Sazegar Lufei Shen Ibrahim Asghar Shah Dirk Dahlhaus Klaus Hofmann Rolf Jakoby 《AEUE-International Journal of Electronics and Communications》2013,67(12):1107-1117
In this paper the bit error rate performance and error vector magnitude of a tunable impedance matching network is analyzed assuming QPSK, 16-QAM and 64-QAM digital modulation schemes. The characterized tunable impedance matching network is based on barium–strontium–titanate ferroelectric thick-film varactors. Inherent dispersive behavior is subsumed into the forward transmission of the passive device. Due to this nonlinear phase response, in general to maximize the overall system performance, an agile tuning of the varactor values is demonstrated, taking into account the phase and group delay of s21 parameter. Detailed signal simulation results based on measured data of a testbed are presented. The influence of varying matched impedances on the tuning behavior with different modulation bandwidths is discussed at a center frequency of 1.9 GHz. 相似文献
99.
The time-dependent mechanical behavior of textiles has particular importance. One of such behaviors is stress relaxation. When strain is applied constantly, there is a decreased stress with time in viscoelastic materials, which is called stress relaxation. The aim of this study is to investigate the effect of knot’s geometry (surgeon, square and eight) and the number of knots on the tensile and stress relaxation properties of the polyester yarn. Significant differences were observed for the tensile characteristics of the yarn in the presence of the knot. Generally, the knotted yarns demonstrated lower tensile stress and strain at failure. Moreover, the results revealed that the stress relaxation behavior of the yarn is affected by the number of knots and their geometry. The yarn without knot exhibited the highest stress relaxation percent while the yarn with the surgeon’s knot displayed the least stress relaxation percent. On the other hand, increasing the number of knots led to a decrease in the percentage of yarn stress relaxation. 相似文献
100.
Ali Asghar Ghorbanpour Khamseh Michele Miccio Giovanna Ferrari 《Chemical Engineering Communications》2013,200(10):1334-1346
Galacturonic acid is a monosaccharide obtained by pectin hydrolysis and a suitable substrate to produce bioethanol by fermentation. This article focuses on quantification of citrus pectin hydrolysis to galacturonic acid and provides new, reliable kinetic parameters for the Michaelis-Menten equation when the well-known commercial Pectinex Ultra SP-L is employed as enzyme. They are: r max = 1.10 g/(L min), K m = 10.42 g/L, and K IGA = 10.05 g/L, as obtained with a great accuracy by a nonlinear regression method and confirmed by the three classical linearization procedures (Lineweaver-Burk, Langmuir, and Eadie-Hofstee). The quantification of product inhibition has been achieved, with its inclusion in the rate equation. A batch reactor model yields perfect agreement between predictions and experiments, even under conditions different from those on which the parameters had been determined by regression. 相似文献