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1.
Cytomegalovirus is the main agent of congenital viral infections. The aim of this study was to compare the incidence of congenital cytomegalovirus infections of two groups of newborns of differing socioeconomic status. Cytomegalovirus was isolated from urine or oropharingeal secretions in 218 children born in a private clinic and 471 born in a public hospital. Positive viral isolates were confirmed with indirect immunofluorescence using monoclonal antibodies. Infection was detected in 12 children (1.82%), four coming from the private clinic (1.86%) and 8 coming from the public hospital (1.81%). Ninety two percent of infected children were asymptomatic. Urine and oropharingeal secretion samples had the same yield for viral isolation. It is concluded that the incidence of congenital cytomegalovirus infection is similar to that described in developed countries.  相似文献   
2.
The amount of data generated by the infra-red and visible cameras at ITER is expected to be considerably larger than most diagnostics. ITER will have 12 infra-red cameras plus 12 visible cameras in four different equatorial port plugs. Each of the ports will have a Plant System Host (PSH) that will provide a standard image of the plant system to the ITER's Control and Data Access and Communication (CODAC) system.The two key functions of these cameras will be the scientific exploitation with the detection of interesting physics events and the operational protection of the machine, namely the first wall. Already assuming high bandwidth requirements for both audio and video, ITER will provide a separate network for this kind of communication, which will be used to transmit both the experimental and informational data provided by the cameras.This paper presents the current camera plant system design and its interaction with ITER CODAC system and networks. Starting from the camera specifications several alternatives for data collection and compression are discussed. The required inputs from CODAC and a first specification for the internal finite state machine are also presented. Finally, a possible hardware straw man design solution for the plant system hardware is proposed.  相似文献   
3.
The synthesis and the biological evaluation of a new family diterpenes are presented. The synthetic studies were inspired by the structural framework of acanthoic acid (1) and yielded a family of compounds that were evaluated as anti-inflammatory agents. Among them, compounds 2, 10, 12, and 16 exhibited a very low nonspecific cytotoxicity and inhibited the synthesis of TNF-alpha with greater than 65 % efficacy at low micromolar concentrations. Cytokine-specificity studies revealed that these compounds also inhibited the synthesis of the proinflammatory cytokines IL-1beta and IL-6, while inhibition of IL-1ra and IL-8 synthesis was marginal and only occurred at high concentrations. Further studies, through EMSA and Western blot analyses, indicated that these compounds decreased the extent of phosphorylation of IkappaBalpha; this suggests that they exert their anti-inflammatory profile by inhibiting NF-kappaB-mediated cytokine synthesis. These findings imply that these diterpenes represent promising leads for the development of novel anti-inflammatory agents.  相似文献   
4.
Most of the ITER optical diagnostics aiming at viewing and monitoring plasma facing components will use in-vessel metallic mirrors. These mirrors will be exposed to a severe plasma environment and lead to an important tradeoff on their design and manufacturing. As a consequence, investigations are carried out on diagnostic mirrors toward the development of optimal and reliable solutions. The goals are to assess the manufacturing feasibility of the mirror coatings, evaluate the manufacturing capability and associated performances for the mirrors cooling and polishing, and finally determine the costs and delivery time of the first prototypes with a diameter of 200 and 500 mm. Three kinds of ITER candidate mock-ups are being designed and manufactured: rhodium films on stainless steel substrate, molybdenum on TZM substrate, and silver films on stainless steel substrate. The status of the project is presented in this paper.  相似文献   
5.
A study of the electrophysical properties of samples prepared by phase transformation of stoichiometric InSb into lnSb-Sb-In2O3 cermet compact has been performed (InSb, In2O3-semiconductors, antimony-metallic conductivity). Samples were prepared by isothermal partial oxidation at 200–500°C for 1–50 h. Bulk and thin-film samples annealed at 400°C for 1–50 h possess relatively constant electrical resistance over the wide temperature interval measured: 4–400 K. The conversion degree, β, and molar ratio, f = In2O3/2Sb were calculated from the isothermal thermogravimetry data according to the reaction equation 2InSb+3/2O2 = In2O3+2Sb at temperatures T < 400°C, when no ascertainable amount of antimony is escaping from the system. The β-value increases with temperature, T, and time of oxidation annealing, t. However, instead of being constant, i.e. f = 0.5, f increases for T > 400°C and t > 1 h. The X-ray powder diffraction, thermogravimetry, differential thermogravimetry and differential thermal analysis measurements and studies revealed that metallic antimony escapes partially from the InSb-Sb-In2O3 system obtained at T ≥ 400°C. As a result, the mutual volume ratio of individual InSb, Sb and In2O3 components is changed, and so also is the overall character of the electrical resistivity of the samples. Due to the partial escape of Sb↑ from the system at T ≥ 400°C, the following reaction is appropriate: 2InSb + 3/2O2 = In2O3 + (2 − z) Sb↑ = In2O3+Sb/f+ zSb, where z is the volatilized portion of Sb and f is the molar ratio of the reaction products, i.e. f = In2O3/(2 − z)Sb = 1/(2 − z). The SEM observations revealed a growing grain size with temperature and time of annealing, lowering the grain-boundary density and thus also the resistivity of the samples. The properties of the obtained ternary compact may be influenced significantly, if instead of stoichiometric InSb, the initial In-Sb with a variable In/Sb ratio is used.  相似文献   
6.
This paper addresses the problem of assessing the diagnosability of hybrid systems modeled by a hybrid automaton coupling methods from the continuous and the discrete event model-based diagnosis fields. The discrete states of the hybrid automaton represent the modes of operation of the system for which the continuous dynamics are specified. The diagnosability of the continuously-valued part of the model is first analyzed and the new concept of mode signature is shown to characterize mode diagnosability from continuous measurements. Continuous dynamics are then abstracted by defining a set of signature-events associated to mode signature changes, preserving this way mode diagnosability. The behavior of the abstract hybrid system is then modeled by a prefix-closed language over the original event alphabet enriched by these additional events. Based on this language, diagnosability analysis of the hybrid system is cast into a discrete-event framework and hybrid diagnosability conditions are provided. A case study based on the Attitude and Orbit Control System of a spacecraft illustrates the method.  相似文献   
7.
Identifiability is the property that a mathematical model must satisfy to guarantee an unambiguous mapping between its parameters and the output trajectories. It is of prime importance when parameters must be estimated from experimental data representing input–output behavior and clearly when parameter estimation is used for fault detection and identification. Definitions of identifiability and methods for checking this property for linear and nonlinear systems are now well established and, interestingly, some scarce works (Braems et al., 2001, Jauberthie et al., 2011) have provided identifiability definitions and numerical tests in a bounded-error context. This paper resumes and better formalizes the two complementary definitions of set-membership identifiability and μ-set-membership identifiability of Jauberthie et al. (2011) and presents a method applicable to nonlinear systems for checking them. This method is based on differential algebra and makes use of relations linking the observations, the inputs and the unknown parameters of the system. Using these results, a method for fault detection and identification is proposed. The relations mentioned above are used to estimate the uncertain parameters of the model. By building the parameter estimation scheme on the analysis of identifiability, the solution set is guaranteed to reduce to one connected set, avoiding this way the pessimism of classical set-membership estimation methods. Fault detection and identification are performed at once by checking the estimated values against the parameter nominal ranges. The method is illustrated with an example describing the capacity of a macrophage mannose receptor to endocytose a specific soluble macromolecule.  相似文献   
8.
9.
Relative and absolute order-of-magnitude models unified   总被引:1,自引:0,他引:1  
The aim of this paper is to analyze under which conditions Absolute Order-of-Magnitude and Relative Order-of-Magnitude models may be concordant and to determine the constraints which guarantee concordance. A graphical interpretation of the constraints is provided, bridging the absolute qualitative labels of two quantities into their corresponding relative relation(s), and conversely. The relative order of magnitude relations are then characterized in the absolute order-of-magnitude world.  相似文献   
10.
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