5-硝基四唑亚铜的合成与表征

以氯化亚铜、5-硝基四唑钠等为原料合成了一种起爆药5-硝基四唑亚铜.利用能谱分析、红外光谱、紫外-可见光谱及元素分析和DSC测试等方法,对5-硝基四唑亚铜进行了结构表征.初步性能研究表明,5-硝基四唑亚铜的初始分解温度为291℃,峰温为324℃,其分解较剧烈,且热稳定性较好;感度测试结果显示,5-硝基四唑亚铜的撞击感度较BNCP钝感,火焰感度比BNCP敏感、比LA钝感.     

Sensitivity and specificity based multiobjective approach for feature selection: Application to cancer diagnosis

The study of the sensitivity and the specificity of a classification test constitute a powerful kind of analysis since it provides specialists with very detailed information useful for cancer diagnosis. In this work, we propose the use of a multiobjective genetic algorithm for gene selection of Microarray datasets. This algorithm performs gene selection from the point of view of the sensitivity and the specificity, both used as quality indicators of the classification test applied to the previously selected genes. In this algorithm, the classification task is accomplished by Support Vector Machines; in addition a 10-Fold Cross-Validation is applied to the resulting subsets. The emerging behavior of all these techniques used together is noticeable, since this approach is able to offer, in an original and easy way, a wide range of accurate solutions to professionals in this area. The effectiveness of this approach is proved on public cancer datasets by working out new and promising results. A comparative analysis of our approach using two and three objectives, and with other existing algorithms, suggest that our proposal is highly appropriate for solving this problem.     

Implementation and evaluation of nonparametric regression procedures for sensitivity analysis of computationally demanding models

The analysis of many physical and engineering problems involves running complex computational models (simulation models, computer codes). With problems of this type, it is important to understand the relationships between the input variables (whose values are often imprecisely known) and the output. The goal of sensitivity analysis (SA) is to study this relationship and identify the most significant factors or variables affecting the results of the model. In this presentation, an improvement on existing methods for SA of complex computer models is described for use when the model is too computationally expensive for a standard Monte-Carlo analysis. In these situations, a meta-model or surrogate model can be used to estimate the necessary sensitivity index for each input. A sensitivity index is a measure of the variance in the response that is due to the uncertainty in an input. Most existing approaches to this problem either do not work well with a large number of input variables and/or they ignore the error involved in estimating a sensitivity index. Here, a new approach to sensitivity index estimation using meta-models and bootstrap confidence intervals is described that provides solutions to these drawbacks. Further, an efficient yet effective approach to incorporate this methodology into an actual SA is presented. Several simulated and real examples illustrate the utility of this approach. This framework can be extended to uncertainty analysis as well.     

Voltage unbalance numerical evaluation and minimization

Among a series of parameters, power quality studies are concerned with voltage unbalances, which represent the voltage magnitude and phase deviation from nominal values. In order to determine the influence of the network's parameters on voltage unbalances, and to provide exact solutions to reduce or even eliminate them, the present study develops and presents two methods. First, a sensitivity analysis is used to determine the influence of each parameter, and then analytical solutions are developed in order to provide the changes needed for correction. The quantification index considered is the symmetrical components method.     

Effect of the inelastic dynamic soil-structure interaction on the seismic vulnerability assessment

This paper presents a study of the influence of inelastic dynamic soil-structure interaction (DSSI) on the seismic vulnerability assessment of buildings. The seismic vulnerability is evaluated in terms of analytical fragility curves constructed on the basis of non-linear dynamic finite elements (FE) analysis. An analytical sensibility strategy is introduced in order to define a suitable size of the motion database to be used for computing fragility curves. The fragility curves developed in this study are compared with reference curves. Concerning the effect of the inelastic DSSI, a general reduction of seismic demand when DSSI phenomena are included is found. Derived fragility curve reflects this seismic demand reduction. The importance of the ground motion database is highlighted in terms of the variability of parameters describing derived fragility curves. Comparison with reference curves are satisfactory. Findings illustrate clearly the importance and the advantages of an adequate DSSI effects evaluation.     

Sensitivity analysis for reliable design verification of nuclear turbosets

In this paper, we present an application of sensitivity analysis for design verification of nuclear turbosets. Before the acquisition of a turbogenerator, energy power operators perform independent design assessment in order to assure safe operating conditions of the new machine in its environment. Variables of interest are related to the vibration behaviour of the machine: its eigenfrequencies and dynamic sensitivity to unbalance. In the framework of design verification, epistemic uncertainties are preponderant. This lack of knowledge is due to inexistent or imprecise information about the design as well as to interaction of the rotating machinery with supporting and sub-structures. Sensitivity analysis enables the analyst to rank sources of uncertainty with respect to their importance and, possibly, to screen out insignificant sources of uncertainty. Further studies, if necessary, can then focus on predominant parameters. In particular, the constructor can be asked for detailed information only about the most significant parameters.     

谈电动机降压启动的应用

通过对笼型电动机降压启动的计算,及对电动机接地故障保护灵敏度的计算,阐述电动机降压启动在实际运用中易被忽视的作用。     

Nuclear data requirements for the ADS conceptual design EFIT: Uncertainty and sensitivity study

In this paper, we assess the impact of activation cross-section uncertainties on relevant fuel cycle parameters for a conceptual design of a modular European Facility for Industrial Transmutation (EFIT) with a “double strata” fuel cycle. Next, the nuclear data requirements are evaluated so that the parameters can meet the assigned design target accuracies. Different discharge burn-up levels are considered: a low burn-up, corresponding to the equilibrium cycle, and a high burn-up level, simulating the effects on the fuel of the multi-recycling scenario.     

Uncertainty quantification in the damage assessment of a cable-stayed bridge by means of fuzzy numbers

Cables offer interesting possibilities in bridge design, but are rather susceptible to damage. Since damage in a cable changes its natural vibration frequency, it can be assessed with a vibration-based finite element updating procedure. However, the natural frequency of a cable is also influenced by the temperature, and the measured frequencies are prone to measurement errors. Therefore, it is useful to check the sensitivity of the identified damage with respect to these factors. This paper presents a methodology based on fuzzy numbers to investigate the propagation of measurement errors and uncertainty on the structural temperature throughout the updating procedure.