金属矿山当前面临的主要问题及对策

叙述了为了解我国金属矿山当前面临的突出问题，必须充分依靠科技进步和技术创新，大力提高矿山企业的技术水平，装备水平和管理水平。     

热损伤岩石物理力学特性演化机制研究进展

为深入了解温度作用下岩石热损伤演化机制,对超深钻探、深地实验室、核废料处置库、地热资源开发等地下岩体工程的安全性和稳定性做出合理性评价,本文通过分析整理国内外文献,系统综述了温度作用下岩体变形破坏方面的研究进展与成果。简述了高温作用下岩石的物理力学特性,侧重总结了岩石物理力学参量随温度变化的演化规律。重点分析了深部岩石材料在高温条件下岩体结构及相关物理场探测技术的最新研究成果,梳理了声发射(AE)、超声波(UT)、X射线分析（XRD）、偏光显微镜(PM)、扫描电子显微镜(SEM)、核成像技术（NMR）以及CT扫描技术等先进的辅助试验设备在热破裂分析中的应用。归纳总结了国内外学者采用的热力耦合模型和数值分析方法及适用条件,简略阐述了温度作用下岩石力学参量变异性特征。最后,指出了当前岩石热损伤研究中存在的一些局限性,并从深部地下工程建设方面展望了未来的发展方向,即多尺度、多场?相探究岩石热损伤机理,宏?细?微观角度系统分析岩石热损伤演化规律。      

Biochemical changes in an intermediate moisture cecina-like meat during storage

Biochemical and microbiological changes in two cecina-like products were evaluated during storage. Two products were prepared, one by salting and the other by infusion in a salt-glycerol solution. The samples were vacuum packed and tested monthly for pH, colour, haematin complex, soluble nitrogen and microbiological spoilage. Proteolysis and increase in pH showed a high correlation for both samples. Temperature-dependent changes in colour and concentration of haematin complex during storage were also found in both samples. The activation energy for haematin transformation was found to be around 1 kcal/mol. Based on the low activation energy for haematin complex degradation (around 1 kcal/mol) for both samples, this process may be regarded as a low energy biochemical process.     

Photonic page buffer based on GaAs multiple-quantum-well modulators bonded directly over active silicon complementary-metal-oxide-semiconductor (CMOS) circuits

We present a 2-kbit, 50-Mpage/s, photonic first-in, first-out page buffer based on gallium arsenide/aluminium-gallium arsenide multiple-quantum-well diodes that are flip-chip bonded to submicrometer silicon complementary-metal-oxide-semiconductor circuits. This photonic chip provides nonvolatile storage (buffering), asynchronous-to-synchronous conversion, bandwidth smoothing, tolerance to jitter or skew, spatial format conversion, wavelength conversion, and independent flow control for the input and the output channels. It serves as an interface chip for parallel-accessed optical bit-plane data. It represents the first smart-pixel array that accomplishes the vertical integration of multiple-quantum-well modulators and detectors directly over active silicon VLSI circuits and provides over 340 transistors per optical input-output. Results from high-speed single-channel testing and real-time array operation of the photonic page buffer are reported.     

Performance enhancement in an uninhabited air vehicle task using psychophysiologically determined adaptive aiding

OBJECTIVE: We show that psychophysiologically driven real-time adaptive aiding significantly enhances performance in a complex aviation task. A further goal was to assess the importance of individual operator capabilities when providing adaptive aiding. BACKGROUND: Psychophysiological measures are useful for monitoring cognitive workload in laboratory and real-world settings. They can be recorded without intruding into task performance and can be analyzed in real time, making them candidates for providing operator functional state estimates. These estimates could be used to determine if and when system intervention should be provided to assist the operator to improve system performance. METHODS: Adaptive automation was implemented while operators performed an uninhabited aerial vehicle task. Psychophysiological data were collected and an artificial neural network was used to detect periods of high and low mental workload in real time. The high-difficulty task levels used to initiate the adaptive automation were determined separately for each operator, and a group-derived mean difficulty level was also used. RESULTS: Psychophysiologically determined aiding significantly improved performance when compared with the no-aiding conditions. Improvement was greater when adaptive aiding was provided based on individualized criteria rather than on group-derived criteria. The improvements were significantly greater than when the aiding was randomly provided. CONCLUSION: These results show that psychophysiologically determined operator functional state assessment in real time led to performance improvement when included in closed loop adaptive automation with a complex task. APPLICATION: Potential future applications of this research include enhanced workstations using adaptive aiding that would be driven by operator functional state.     

The approximation of image blur restoration filters by finite impulse responses

Image blur can often be modeled by a linear spatially invariant, symmetric point spread function. For this class of functions, several restoration filters are known in the literature. The approximation of their frequency transfer functions (ftf's) by the ftf's of small finite impulse response (FIR) filters has been studied. Accurate approximations will be possible by 9 × 9 FIR's with 8-bit elements if the approximation is done in a weighted MMSE sense, and if the truncation of the element values will be carried out such that the errors are small. A heuristic truncation algorithm MINIM will be described. An example of restoration by a 9 × 9 FIR will be shown.     

碎石桩在强夯处理高饱和细粒土地基中的聚能和隔振作用

强夯法一般不适用于处理高饱和细粒土地基。但是,如果在该类地基中预先设置碎石桩,则能获得较好的处理效果。这是因为桩的聚能作用,减小了夯击能的传播损失,提高了每个夯坑的地基加固效果;桩的隔振作用,降低了夯击能对表层地基土的破坏、松动程度;桩的压重作用,减小了夯坑周围土体的隆起。碎石桩还有很好的挤土、置换等作用,从而提高了强夯法在该类地基处理中的适用性。