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61.
Traditional single channel communication in Wireless Sensor Networks (WSN) offers limited network throughput due to frequent interferences and congestion caused by concurrent transmissions in the same neighborhood. On the one hand, successful packet delivery requires mostly multiple retransmissions because of frequent collisions which also uses much battery. On the other hand, concurrent transmissions over multiple channels not only offer better network throughput and delays, but also reduce power consumption as packet collisions are minimized or eliminated depending upon the efficiency of the concerned channel assignment scheme. This may ensure QoS requirements of transmissions demanding high bandwidth and those that are delay sensitive such as in the case of wireless body area networks. In this paper, we consider a multiple channel wireless body area networks and propose GATE, a theoretical game approach to adapt the channel bandwidth to the volume traffic requirement. In this way, medical video and audio traffics which are likely to be much bandwidth consumer are mainly considered using their priority classes. The simulation results show good performances of the proposed system in terms of increasing throughput and significantly reducing delay and energy consumption.  相似文献   
62.
Cognition, Technology & Work - Subjective Evidence-Based Ethnography (SEBE) is a family of methods developed in digital ethnography for investigation in social science based on subjective...  相似文献   
63.
Various structurally modified analogues of FR235222 (1), a natural tetrapeptide inhibitor of mammalian histone deacetylases, were prepared in a convergent approach. The design of the compounds was aimed to investigate the effect of structural modifications of the tetrapeptide core involved in enzyme binding in order to overcome some synthetic difficulties connected with the natural product 1. The modifications introduced could also help identify key structural features involved in the mechanism of action of these compounds. The prepared molecules were subjected to in vitro pharmacological tests, and their potency was tested on cultured cells. Two of the components of the array were found to be more potent than the parent compound 1 and almost as efficient as trichostatin A (TSA). These results demonstrate that it is possible to synthesize highly active cyclic tetrapeptides using commercially available amino acids (with the exception of 2-amino-8-oxodecanoic acid, Ahoda). The nature of the residue in the second position of the cyclic peptide and the stereochemistry of the Ahoda tail are important for the inhibitory activity of this class of cyclic tetrapeptide analogues.  相似文献   
64.
Some construction laws require the integration of an open thermosyphon system having multiple functions to the building roof. In order to analyze the efficiency of this system, a numerical model was developed. This model is based on the study of the natural convection coupled with radiative heat transfer in an inclined air channel. Two configurations are studied, the first one is a simple channel formed by two parallel plates and the second one is equipped with fin blades joined to the upper plate. The air flow in the channel which is due to the buoyancy forces is fully turbulent and the turbulence was modeled using the k‐ε model. Some numerical results obtained were validated using the experimental ones of Khedari et al. (2002) and those of Nouanégué and Bilgen (2009). The effect of the radiative heat transfer on the mean Nusselt number was shown. Correlations for Nusselt numbers were obtained for the two configurations as functions of the geometric parameters and the Rayleigh number. The main objective of this study is to use these correlations in other models to facilitate the operation of this system  相似文献   
65.
In this study, nanostructured γ-alumina has been used as an adsorbent for nickel removal from aqueous solution in a fixed-bed column. Comparison of Thomas, Yoon-Nelson, and Adams-Bohart models with the experimental kinetic results was done and model parameters were evaluated using a linear regression analysis for Ni2+ adsorption in different bed heights, initial concentrations, and flow rates. The obtained experimental data was in good agreement with Thomas and Yoon-Nelson models, but in the case of Adams-Bohart model, a low correlation coefficient was observed.  相似文献   
66.
67.
In this study, the presence of Coxiella burnetii (Cb) in cheese produced in Southern Italy from milk of cow, buffalo, and small ruminants has been evaluated. Two tests based on real-time PCR assay targeting CB IS1111 element were performed. First an assay based on the use of Taq-Man probe was performed to screen the samples. The positive samples were confirmed using both a SyBr Green test and the evaluation of the melting temperature of the amplicons. In addition, all cheese samples were also tested to determine the milk species utilized (Regulation EC 273/2008). The samples of cheese produced with a milk mix from different species were not included into the study. A total of 169 cheese samples were tested, and the obtained results showed an overall prevalence of Cb of 21.3 % with variation between species. A positivity rate of 39 % was observed in cow’s cheese while Cb DNA was detected in 26 % of cheese samples made from small ruminants’ milk. However, the bacterium was found only in 6.9 % of buffalo’s cheese samples. A direct association between prevalence and milk used for the production was highlighted (χ 2  = 19.12). The statistical analysis of the prevalence in the samples from cattle and small ruminants compared with those from buffalo shows an OR of 8.4 and 4.9, respectively.  相似文献   
68.
The major types of nondisulphide cross‐linking which cause milk protein aggregation were investigated in milk, with and without lactose, heated at 95 °C for up to 8 h. Compared with the milk containing no lactose, the milk containing lactose showed a smaller increase in pH, a larger increase in pH 4.6 soluble nitrogen, much smaller increase in lysinoalanine (LAL) and a much higher percentage of cross‐linked proteins. It was concluded that cross‐linking in milk products containing lactose occurs mainly via Maillard reaction products, and in milk products with no lactose, it occurs mainly via isopeptide linkages such as in LAL.  相似文献   
69.
A quasi-two-dimensional solidification benchmark experiment with controlled thermal boundary conditions is proposed. The experiment consists in solidifying a rectangular ingot of Sn–3 wt.%Pb alloy using two lateral heat exchangers to extract the heat flux from one or two sides of the sample. The temperature difference between the two sides of the heat exchangers may vary from 0 to 40 K and the cooling rate from 0.02 to 0.04 K/s. This slow-cooling condition has been used to promote segregation formation. An array of fifty thermocouples placed on the corresponding sample walls is used to determine the instantaneous temperature distribution. During the solidification process, the temperature field is recorded versus time and analyzed. This makes it possible to estimate the change in temperature due to natural convection, the velocity field and the solidification macrostructure and segregation behavior. After each experiment, the segregation patterns are obtained by X-ray analysis and confirmed by eutectic fraction measurements. The local solute distribution is determined by means of induction coupled plasma analysis.  相似文献   
70.
The authors present a method for measuring the temperature-depth profile in a lossy material by applying Kalman algorithm to radiometric signals. The method employs a correlation microwave radiometer. It uses both short-range weighting functions and the delay times of the correlator. An experimental verification of this new thermal inversion approach is presented. The thermal noise is received in the microwave domain, by a S band radiometer by using an automatic experimental bench. A feature of this method is that it can be used in biomedical applications.  相似文献   
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