α-Tocopherol alteration of soybean antiherbivory toTrichoplusia ni larvae

The antioxidant vitamin E, <img src="/content/k1865k06h886025l/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-tocopherol, was tested as a candidate elicitor of alterable antiherbivory in soybean plants against cabbage looper larvae. Although a nonspecific antioxidant, vitamin E proved elicitory to the involved sulfhydryl-dependent receptor-energy transducer protein in soybean plasma membrane. Effects of <img src="/content/k1865k06h886025l/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-tocopherol were dependent on dosage, time, and space in the plant. The observed elicited effects were all decreases in herbivory. The best negative phytochemical correlate of looper feeding was the percentage of increased total HPLC peak area of extractables from elicited as compared to nonelicited leaves. Some specific compounds, e.g., glyceollins, were quantitatively major components of the total profile of secondary metabolites.     

基于朴素基因表达式编程挖掘紧致函数

基因表达式编程(GEP)是一种基因型和表现型相分离的进化新模型,为了挖掘紧致的函数关系,分析了进化系统各因素对挖掘紧致函数的影响,提出了带紧致压力的适应度函数来进化函数紧致解。实验表明,带有紧致压力的适应度函数能自动进化计算机程序,适合挖掘的紧致关系,在挖掘紧致函数中,朴素基因表达式编程(NGEP)比GEP提高效率21.7%,与不带压力的系统相比,GEP的平均压缩了31.2%,NGEP系统平均压缩了42.5%;NGEP较GEP更容易发现紧致解,且函数表达形式更容易理解,丰富了NGEP理论.     

Catalytic Combustion of Model Carbon Particles (CPs) over Pt/β-SiC Catalyst

Platinum catalyst supported on a medium surface area <i><img src="/content/l180w9r66167580u/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0"></i>-SiC was successfully used for the catalytic combustion of model carbon particles and compared to a catalyst supported on a low surface area <i><img src="/content/l180w9r66167580u/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0"></i>-SiC. The <i><img src="/content/l180w9r66167580u/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0"></i>-SiC-based catalyst showed no deactivation as a function of cycling tests while a strong deactivation was observed on the <i><img src="/content/l180w9r66167580u/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0"></i>-SiC-based catalyst. This deactivation was attributed to the progressive encapsulation of the platinum particles by a layer of silica which built up during the combustion cycle. These results render possible the use of Pt/<i><img src="/content/l180w9r66167580u/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0"></i>-SiC catalyst as a diesel carbon particle catalytic filter with continuous regeneration.     

辣椒红色素的提取工艺及稳定性研究

红辣椒中含有纯天然辣椒红色素，研究了辣椒红色素的几种提取方法。用有机溶剂从辣椒中提取红色素，同时对不同温度、不同时间下的色素提取率进行测试，以确定最佳提取条件；研究发现，乙酸乙酯法可以有效地去除辣椒中的辣味，使产品应用于更广泛的领域。本文还研究了辣椒红色素对pH值、光照、温度、金属离子的稳定性。     

基于加权平滑l_0范数的单快拍波达方向估计

针对现有基于压缩感知的DOA估计算法估计精度不高的问题,提出一种基于加权平滑l0范数的单快拍DOA估计算法。所提算法采用一种新的加权方式,在构造一个恰当的平滑连续函数后,根据接收数据的初始解确定一个合适的递减的{σ}序列[σ_1,σ_2,?,σ_J],并对每一个σ值,用最速下降法来求解l0范数的逼近函数H_σ(S)的最小值;然后将该σ值作为下一次迭代的初始值,并在每次迭代开始时更新权值,通过多次的迭代获得逼近函数的最小解,即逼近的最小l0范数。通过仿真实验表明所提算法可对DOA进行有效估计,且容易实现、精度较高,与未加权的改进平滑l_0范数DOA估计方法相比具有更好的估计性能。     

The influence of platinum on the maintenance of α-Al2O3 as a protective scale

The influence of externally located platinum on the isothermal stability of <img src="/content/u73l247g42153330/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-Al<sub>2</sub>O<sub>3</sub> scales formed at high temperatures has been examined. It has been observed that a nickel-base alloy forms an external scale of <img src="/content/u73l247g42153330/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-Al<sub>2</sub>O<sub>3</sub> during oxidation at 1200°C, but this scale breaks down isothermally, enabling a faster-growing Cr<sub>2</sub>O<sub>3</sub>-rich scale to develop. However, in the presence of platinum metal alongside the specimen in the furnace hot zone, the breakdown of the <img src="/content/u73l247g42153330/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-Al<sub>2</sub>O<sub>3</sub> scale is postponed for a substantial period of time. It appears that platinum, as the volatile species PtO<sub>2</sub>, is incorporated into the growing <img src="/content/u73l247g42153330/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-Al<sub>2</sub>O<sub>3</sub> scale where it either influences the stress relief mechanism at temperature or reduces oxidation growth stress generation and thus significantly enhances the isothermal stability of the scale.     

基于无秩树自动机的信息抽取技术研究

针对目前基于网页结构的信息抽取方法的缺陷,提出了一种基于无秩树自动机的信息抽取技术,其核心思想是通过将结构化(半结构化)文档转换成无秩树,然后利用(k,l)-contextual树构造样本自动机,依据树自动机接收和拒绝状态来对网页进行数据的抽取.该方法充分利用结构,依托树自动机将传统的以单一结构途径的信息抽取方法与文法推理原则相结合,得到信息抽取规则.实验结果表明,该方法与同类抽取方法相比在准确率、召回率以及抽取所需时间上均有所提高.     

Role of electron-phonon interaction in lattice dynamics and superconductivity of oxide spinel LiTi2O4

The lattice dynamics of an oxide spinel LiTi<sub>2</sub>O<sub>4</sub> is studied by taking account of the electron-phonon (EP) interaction derived on the basis of the realistic tight-binding bands fitted to the first-principles bands. Due to the characteristic dependences of the EP interaction on wavevectors and vibrational modes, a remarkable frequency renormalization of the O vibrational modes, which hybridize with the Ti vibrational modes, is obtained over a wide region of the Brillouin zone. The overall features of the calculated phonon density of states are in agreement with those observed by the inelastic neutron scattering measurements. By using the EP interaction and the renormalized phonon frequencies we have calculated the EP spectral function<i><img src="/content/j26332026577p1l1/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0"></i> <sup>2</sup> <i>F(<img src="/content/j26332026577p1l1/xxlarge969.gif" alt="ohgr" align="BASELINE" BORDER="0">)</i>. The superconducting transition temperature, gap function, and tunneling spectra are calculated by solving the Éliashberg equation. The results agree well with the observations.     

结合l1/2范数与显著性约束的背景减除

传统背景减除模型在背景静止和前景对象移动较快时提取到的前景效果较好,但当背景变化或前景对象移动缓慢时容易将动态背景误判为前景或检测出的前景有较多空洞。针对传统背景减除模型在动态背景和前景对象移动缓慢条件下存在前景检测精度下降的问题,提出一种基于l_1/2范数与显著性约束的背景减除模型。将观测数据分为低秩背景、运动前景和动态干扰3类,利用l_1/2范数约束运动前景加强前景稀疏性,有效抑制动态背景对前景提取造成的干扰,提高运动前景在动态背景中的检测精度。引入视频每一帧的显著性约束,通过对每一帧图像进行低秩稀疏分解来检测移动缓慢的目标。实验结果表明,该模型对于复杂场景具有较强的适应能力,可有效去除动态背景对前景的干扰,快速检测出移动缓慢的前景对象,相比于l_1/1/2-RPCA背景减除模型的平均查全率、查准率和调和平均值分别提升了9、14和10个百分点。     

Isochoric p-ρ-T Measurements on 1,1-Difluoroethane (R152a) from 158 to 400 K and 1,1,1-Trifluoroethane (R143a) from 166 to 400 K at Pressures to 35 MPa

The <i>p</i>-<img src="/content/h51h437771l84g21/xxlarge961.gif" alt="rgr" align="MIDDLE" BORDER="0">-<i>T</i> relationships have been measured for 1,1-difluoroethane (R152a) and 1,1,1-trifluoroethane (R143a) by an isochoric method with gravimetric determinations of the amount of substance. Temperatures ranged from 158 to 400 K for R152a and from 166 to 400 K for R143a, while pressures were up to 35 MPa. Measurements were conducted on compressed liquid samples. Determinations of saturated liquid densities were made by extrapolating each isochore to the vapor pressure, and determining the temperature and density at the intersection. Published <i>p</i>-<img src="/content/h51h437771l84g21/xxlarge961.gif" alt="rgr" align="MIDDLE" BORDER="0">-<i>T</i> data are in good agreement with this study. For the <i>p</i>-<img src="/content/h51h437771l84g21/xxlarge961.gif" alt="rgr" align="MIDDLE" BORDER="0">-<i>T</i> apparatus, the uncertainty of the temperature is ±0.03 K, and for pressure it is ±0.01% at <i>p</i>>3 MPa and ±0.05% at <i>p</i><3 MPa. The principal source of uncertainty is the cell volume (<img src="/content/h51h437771l84g21/xxlarge8764.gif" alt="sim" align="MIDDLE" BORDER="0">28.5 cm<sup>3</sup>), which has a standard uncertainty of ±0.003 cm<sup>3</sup>. When all components of experimental uncertainty are considered, the expanded relative uncertainty (with a coverage factor <i>k</i>=2 and thus a two-standard deviation estimate) of the density measurements is estimated to be ±0.05%.