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91.
Forensic examiners are in an uninterrupted battle with criminals in the use of Big Data technology. The underlying storage system is the main scene to trace the criminal activities. Big Data Storage System is identified as an emerging challenge to digital forensics. Thus, it requires the development of a sound methodology to investigate Big Data Storage System. Since the use of Hadoop as Big Data Storage System continues to grow rapidly, investigation process model for forensic analysis on Hadoop Storage and attached client devices is compulsory. Moreover, forensic analysis on Hadoop Big Data Storage System may take additional time without knowing where the data remnants can reside. In this paper, a new forensic investigation process model for Hadoop Big Data Storage System is proposed and discovered data remnants are presented. By conducting forensic research on Hadoop Big Data Storage System, the resulting data remnants assist the forensics examiners and practitioners for generating the evidences.  相似文献   
92.
This study examines the financial feasibility of producing ethanol biofuel from sugar beets in central North Dakota. Under the Energy Independence and Security Act (EISA) of 2007, biofuel from sugar beets uniquely qualifies as an “advanced biofuel”. EISA mandates production of 21 billion gallons of advanced biofuels annually by 2022. A stochastic simulation financial model was calibrated with irrigated sugar beet data from central North Dakota to determine economic feasibility and risks of production for 0.038 hm3y−1 (or 10 MGY (Million Gallon per Year) and 0.076 hm3y−1 (or 20 MGY) ethanol plants. Study results indicate that feedstock costs, which include sugar beets and beet molasses, account for more than 70 percent of total production expenses. The estimated breakeven ethanol price for the 0.076 hm3y−1 plant is $400 m−3 ($1.52 per gallon) and $450 m−3 ($1.71 per gallon) for the 0.038 hm3y−1 plant. Breakeven prices for feedstocks are also estimated and show that the 0.076 hm3y−1 plant can tolerate greater ethanol and feedstock price risks than the 0.038 hm3y−1 plant. Our results also show that one of the most important factors that affect investment success is the price of ethanol. At an ethanol price of $484.21 m−3 ($1.84 per gallon), and assuming other factors remain unchanged, the estimated net present value (NPV) for the 0.076 hm3y−1 plant is $41.54 million. By comparison, the estimated NPV for the 0.038 hm3y−1 plant is only $8.30 million. Other factors such as changes in prices of co-products and utilities have a relatively minor effect on investment viability.  相似文献   
93.
In this paper, the effect of heat transfer on the C49–C54 phase transformation in TiSi2 thin film was investigated for the first time. Variation of the height of the chamber in the furnace during the annealing process was found to affect the sheet resistance (Rs) value of TiSi2. By employing a moderate height of the annealing chamber, which makes it possible for the gas molecules inside to be more turbulent, the reduction of Rs can be achieved. From the standpoint of heat transfer theory, it has been proved in this paper that the enhancement of the thermal energy exchange between the wafer and the surrounding ambient contributes to the low resistivity C54 phase formation.  相似文献   
94.
Globally, point-of-care testing (POCT) is the most preferable on-site technique for disease detection and includes a rapid diagnostic test (RDT) and fluorescent immunochromatographic strip test (FICT). The testing kits are generally insufficient in terms of signal enhancement, which is a major drawback of this approach. Sensitive and timely on-site POCT methods with high signal enhancement are therefore essential for the accurate diagnosis of infectious diseases. Herein, we prepare cysteamine-gold coated carboxylated europium chelated nanoparticle (Cys Au-EuNPs)-mediated POCT for the detection of the H5N1 avian influenza virus (AIV). Commercial nanoparticles were used for comparison. The spectral characteristics, surface morphologies, functional groups, surface charge and stability of the Cys AuNPs, EuNPs, and Cys Au-EuNPs were confirmed by UV-visible spectrophotometry, fluorescence spectrometry, transmission electron microscope with Selected area electron diffraction (TEM-SAED), Fourier-transform infrared spectroscopy (FTIR) and zeta potential analysis. The particle size distribution revealed an average size of ~130 ± 0.66 nm for the Cys Au-EuNPs. The Cys Au-EuNP-mediated RDT (colorimetric analysis) and FICT kit revealed a limit of detection (LOD) of 10 HAU/mL and 2.5 HAU/mL, respectively, for H5N1 under different titer conditions. The obtained LOD is eight-fold that of commercial nanoparticle conjugates. The photo luminance (PL) stability of ~3% the Cys Au-EuNPs conjugates that was obtained under UV light irradiation differs considerably from that of the commercial nanoparticle conjugates. Overall, the developed Cys Au-EuNPs-mediated dual-mode POCT kit can be used as an effective nanocomposite for the development of on-site monitoring systems for infectious disease surveillance.  相似文献   
95.
The effect of the presence of a feedback channel on the transmission of information was first considered by Shannon, who showed that the capacity of a memoryless channel is not increased by the existence of a feedback link even if the feedback link is noiseless. Later it was shown that the information on a feedback channel can be used to improve considerably the performance of channel coding. In this work we study the transmission of an information source through a fading channel with feedback, modeled by a finite-state channel in the Gilbert-Elliot sense. We show that by employing the feedback information in the quantizer design for this finite-state channel, one can achieve lower overall distortion compared to the case where feedback is not available. The feedback channel is used to estimate the channel state using a hidden Markov model, and a quantizer matched to the channel state is chosen based on this information.  相似文献   
96.
97.
Age differences were assessed in a conceptual model that seeks to explain how acculturation affects psychological well-being among Mexican-Americans. The data were from a national probability sample of 859 persons of Mexican descent. It was hypothesized that low acculturation creates financial stress. Moreover, low acculturation and financial stress were in turn predicted to erode feelings of personal control and self-esteem. Finally, diminished feelings of control and low self-esteem were hypothesized to exert a negative impact on psychological well-being. When data from respondents of all ages were assessed, empirical support was found for all of the hypotheses except the linkage between acculturation and financial stress. However, few age differences emerged in the model. The authors conclude that older Mexican-Americans may not be more vulnerable to the stressors associated with acculturation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
98.
In this study, a high performance poly(ether sulfone) (PES) hollow fiber ultrafiltration (UF) membrane has been prepared for removal of natural organic matter (NOM). The membrane was spun from a dope solution containing PES/poly (vinyl pyrrolidone) (PVP 40K)/N‐methyl‐2‐pyrrolidone (NMP) by using a wet‐spinning process. Characterization of the membrane in terms of pure water flux, molecule weight cut‐off (MWCO), and retention for a model humic acid (HA) were conducted, and the fouling resistance was analyzed. The experimental results showed that the membrane had a pure water permeability of 20 × 10?5 L m?2 h?1 Pa?1 and a nominal MWCO of 6000 Da. The results also showed that the membrane retention for humic acid was over 97% and both productivity and selectivity for HA increased with increasing feed velocity. The PES membrane in this study exhibited a much lower fouling tendency than the commercial polysulfone membrane. SEM images revealed that the membrane had an outer dense skin and a porous inner surface. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 430–435, 2006  相似文献   
99.
A pilot study for reclamation of secondary treated sewage effluent in Singapore was conducted using a MF/RO system with the capacity of 20 m3/d. A 0.1 μm MF membrane from Asahi and RE-4040-FL RO membrane from Saehan were used in this study. The pilot plant consists of six spiral-wound RO elements. The RO train was configured in single stage. The pilot plant was designed with automatic control system and it was operated continuously (24 h) during the study. Trial runs on various flux rates of the RO membrane at different operating pressures were conducted over 3 months. The pilot results showed that the optimal operation flux rate of the RO membrane ranged from 10 to 15 gal/f2/d (GFD) for this application. The normalized flux after CIP was 97% of the initial one. At a flux rate of 10 GFD and water recovery of 50%, the average operating pressure of 57 psi was noted corresponding to a high normalized flux of 38 L m−2 h−1 MPa−1 at 25°C. Rejections of the RO membrane in terms of conductivity, TOC, ammonium and nitrate were higher than 96%,97%,90% and 85%, respectively. It was concluded that the RO permeate quality in terms of conductivity, turbidity, TOC, ammonium, nitrate, hardness, total bacteria and total coliform matched the quality of high-grade water (NEWater) for use in the electronics industry.  相似文献   
100.
In this study, plasma levels of magnesium, calcium, zinc and copper were simultaneously determined in pregnancies complicated by either abortion, intrauterine growth retardation (IUGR), diabetes or EPH (edema, proteinuria, hypertension) gestosis. The levels of the four cations in non-pregnant women and in healthy, pregnant women were also determined. Compared with controls, a significant decrease in magnesium, with increase of the Ca/Mg ratio, was found in spontaneous abortions, but not when patients had a successful continuation of pregnancy. In EPH gestosis, total calcium was reduced, with a significant decrease of the plasma Ca/Mg ratio. A slight, but significant, increase in plasma zinc was observed in women affected by either diabetes or IUGR, probably as a result of reduced zinc uptake by the fetus. In addition, higher copper levels were found in the pathologies studied, with the exception of missed abortions. The possible role of an altered Ca/Mg ratio homeostasis in relation to gestational pathologies is discussed.  相似文献   
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