人群头发元素分布及某些特征研究

本文介绍用堆中子活化分析法测定人群头发中I、Br、Mg、Mn、Cu、Na、V、Cl、Al、Ca、S等11种元素。研究人发中元素分布特征、相关性特征、性别年令分布特征。方法学中还从法庭科学应用角度介绍同一性识别中差异率和重合几率的双判据方法。     

Multidisciplinary optimization of gas-quenching process

Distortion as a result of the quenching process is predominantly due to the thermal gradient and phase transformations within the component. Compared with traditional liquid quenching, the thermal boundary conditions during gas quenching are relatively simple to control. By adjusting the gas-quenching furnace pressure, the flow speed, or the spray nozzle configuration, the heat-transfer coefficients can be designed in terms of both the component geometry and the quenching time. The purpose of this research is to apply the optimization methodology to design the gas-quenching process. The design objective is to minimize the distortion caused by quenching. Constraints on the average surface hardness, and its distribution and residual stress are imposed. The heat-transfer coefficients are used as design variables. DEFORM-HT is used to predict material response during quenching. The response surface method is used to obtain the analytical models of the objective function and constraints in terms of the design variables. Once the response surfaces of the objective and constraints are obtained, they are used to search for the optimum heat-transfer coefficients. This process is then used instead of the finite-element analysis. A one-gear blank case study is used to demonstrate the optimization scheme.     

电感电容损耗电阻的讨论

通过对电容电感阻抗的测量，发现实验值偏离理论值。定性地分析了误差的来源，得出的结论是电感电容内部的损耗电阻随着频率的变化而变化，变化方向相反而并非相同。     

Smart pricing scheme: A multi-layered scoring rule application

Defining appropriate pricing strategy for smart environment is important and complex task at the same time. It holds the primal fraction in Demand Response (DR) program. In our work, we devise an incentive based smart dynamic pricing scheme for consumers facilitating a multi-layered scoring rule. The proposed strategy characterizes both incentive based DR and price based DR programs facilities. This mechanism is applied between consumer agents (CA) to electricity provider agent (EP) and EP to Generation Company (GENCO). Based on the Continuous Ranked Probability Score (CRPS), a hierarchical scoring system is formed among these entities, CA–EP–GENCO. As CA receives the dynamic day-ahead pricing signal from EP, it will schedule the household appliances to lower price period and report the prediction in a form of a probability distribution function to EP. EP, in similar way reports the aggregated demand prediction to GENCO. Finally, GENCO computes the base discount after running a cost-optimization problem. GENCO will reward EP with a fraction of discount based on their prediction accuracy. EP will do the same to CA based on how truthful they were reporting their intentions on device scheduling. The method is tested on real data provided by Ontario Power Company and we show that this scheme is capable to reduce energy consumption and consumers’ payment.     

Dynamic response of Ti3SiC2 under shock compression up to 112 GPa

Ti₃SiC₂ is of interest due to its unique dual nature reminiscent of both brittle ceramics and ductile metals at ambient conditions. In this work, plate-impact experiments have been performed to study the dynamic behavior of Ti₃SiC₂ under shock compression up to 112 GPa by using laser velocity interferometer and electric pin techniques. Hugoniot elastic limits (HEL), spall strength, and Hugoniot equations of state have been obtained based on measured particle velocity profiles and shock wave velocities. The ratio of spall strength to HEL for Ti₃SiC₂ is larger than brittle ceramics but smaller than metals. This result indicates that the dual nature of Ti₃SiC₂ remains at least up to 10 GPa. On the other hand, the linearity of the Hugoniot equation of state, $D=6.9\text{0}1(22)+1.153(53)u_{\text{p}}$, suggests that the initial structure of Ti₃SiC₂ should be stable up to 112 GPa, in contrast to the result reported by Jordan et al. [J. Appl. Phys., 93 (2003) 9639].     

Modeling of fast pulse responses in the Multitrack: an advanced TAP reactor

A detailed transport model for the Multitrack setup, a TAP-like system, has been developed, which allows further analysis of adsorption, diffusion and catalysis phenomena. This includes the transport in the void part between the pulse valve and the reactor inlet. The effects of viscous flow and thermal transpiration, aspects that have not been studied in detail before for this type of setup, have been analyzed. A new expression for the modeling of the output signal is proposed depending on the positioning of the MS detector used in the study. The transport parameters of the model have been estimated by the analysis of the experimental pulse responses of the empty reactor system and the reactor charged with an inert packed bed. The proposed model reproduces the experimental pulse responses very well, and therefore can be extended to study systems with reacting or adsorbing beds by including the corresponding rate equations for the processes occurring in the bed of particles.     

Relation between structural evolution of the Longmenshan orogenic zone and sedimentation of its foreland basin

In order to determine the area for oil and gas exploration in China's north Sichuan basin, we have divided the time during which the Longmenshan foreland basin was formed into five periods, based on the sedimentary response relationship of the fore-land basin to structural evolution: 1) a late Triassic Noric period; 2) an early-Middle Jurassic period; 3) a late Jurassic to early Cre-taceous period; 4) a late Cretaceous to Paleogene-Neogene period and 5) the Quaternary period. As well, we analyzed the sedimen-tary environment and lithologic features of every basin-forming period. The results show that there are several favorable source-reservoir-cap assemblages in our study area, making it a major region for future oil and gas exploration in China's northern Sichuan basin.     

大变幅扬程多机组泵站并联运行水泵性能分析

分析了大变幅扬程下灌溉泵站并联运行水泵机组性能,提出了提高泵站装置效率的方法。