基于程序分析的二进制软件模糊测试

针对现有二进制模糊测试难以深入程序内部发现漏洞这一问题, 提出一种融合硬件程序追踪、静态分析和混合执行3种技术的多角度优化方案. 首先, 利用静态分析和硬件追踪评估程序路径复杂度及执行概率; 之后, 根据路径复杂度与执行概率进行种子选择和变异能量分配; 同时, 利用混合执行辅助种子生成并记录关键字节用于针对性变异. 实验结果表明, 相比现有模糊测试方案, 该方案在多数情况下能发现更多的程序路径和crash.     

贵州25个辣椒主栽品种品质分析与评价

目的 探究贵州主栽辣椒的品质差异,并进行样品品质综合性评价。方法 对25种贵州主栽辣椒的营养指标进行测定,针对品质指标进行统计分析、相关性分析和聚类分析。结果 25种辣椒果实的含水量、辣椒红素、还原糖、总氨基酸、粗脂肪、粗纤维、辣椒素和二氢辣椒素的平均含量分别为0.53 g/g、56.68μg/g、11.08 mg/g、34.86μmol/g、14.95%、22.41%、2.20 g/kg、1.11 g/kg。各个品质在不同材料间的差异明显,其中以二氢辣椒素含量的变异系数最大,达70.24%,最小的为粗纤维,只有13.19%。通过隶属函数分析可知,综合品质最优的品种为黔椒11号。通过相关性分析得出辣椒红素与还原糖、总氨基酸显著负相关(P<0.05),与辣椒素、二氢辣椒素显著正相关(P<0.05);还原糖与总氨基酸、辣椒素显著负相关(P<0.05),与粗脂肪、粗纤维、二氢辣椒素显著正相关(P<0.05);总氨基酸与粗脂肪、含水量、辣椒素、二氢辣椒素显著正相关(P<0.05);粗纤维与辣椒素显著正相关(P<0.05)。通过聚类分析将所有样品分为4类。第1...     

Syntheses, Crystal Structures and Photophysical Properties of a Series of LnIII (Ln?=?Sm, Tb, Pr) Coordination Polymers

Four new lanthanide(Ш) coordination polymers, [Ln(p-aminobenzoate)₂(DMF)(HCOO) (H₂O)]_n (Ln = Sm 1, Tb 2, Pr 3) and {[Pr(2,5-dcp)(CH₃COO)(H₂O)]·1.5H₂O}_n (4) (DMF = N,N-dimethylformamide, 2,5-dcp = pyridine-2,5-dicarboxylate), have been synthesized by hydrothermal method. The structures are determined by the single-crystal X-ray diffraction. The four polymers all crystallize in the monoclinic space group P2₁/n. Polymers 1 and 2 are isostructural; both Sm^III ion of polymer 1 and Tb^III ion of polymer 2 are eight-coordinate. Although polymer 3 possesses the same asymmetric unit as polymers 1 and 2, the three are not isomorphous. The Pr^III ions in polymers 3 and 4 are nine-coordinate. In polymers 1, 2 and 3 the neighboring units are bridged by formyloxy and extend into infinite chains, which are connected by hydrogen bonds to form a hydrogen bond network. However, polymer 4 is bridged by pyridine-2,5-dicarboxylate and acetates to form an infinite 3D network. At room temperature, the IR, UV–Vis–NIR and emission spectra of the four polymers were measured and analyzed. The four polymers emit in the visible or NIR region. The luminescent properties are discussed.     

HgCdTe长波光电二极管列阵的等离子体修饰

报道了HgCdTe长波离子注入n+-on-p型光电二极管列阵低能氢等离子体修饰的研究成果.基于采用分子束外延(MBE)技术生长的HgCdTe/CdTe薄膜材料,通过注入窗口的光刻与选择性腐蚀、注入阻挡层的生长、形成光电二极管的B+注入、光电二极管列阵的低能氢等离子体修饰、金属化和铟柱列阵的制备等工艺,得到了氢等离子体修饰的n+-on-p型HgCdTe长波光电二极管列阵.从温度为78 K的电流与电压(I-V)和动态阻抗与电压(R-V)特性曲线中,发现经过低能氢等离子体修饰的HgCdTe红外长波光电二极管列阵动态阻抗极大值比未经过修饰处理的提高了1～2倍,并在反向偏压大于动态阻抗极大值所处的偏压时动态阻抗得到更为明显的提升.这表明低能氢等离子体修饰可以抑制HgCdTe光电二极管列阵暗电流中的带带直接隧穿电流Ibbt和缺陷辅助隧穿电流Itat,从而能提高长波红外焦平面探测器工作的动态范围和探测性能的均匀性.     

基于邻域重心约束的点云模型光顺算法

从统计的角度分析点云模型的光顺除噪,并提出了一个针对随机噪声的邻域重心约束光顺算法．此方法通过极小化邻域重心约束的局部邻域目标函数达到局部光顺的目的,不需要进行表面重构并保证选代过程中点云模型主体形状不变,有效地克服了拉普拉斯算子所造成的过度收缩与聚集现象．实验表明此方法不仅计算稳定、速度快,而且简便易用．     

Self-assembled ionic liquid synthesis of nitrogen-doped mesoporous TiO2 for visible-light-responsive hydrogen production

Nitrogen-doped mesoporous TiO₂ has been synthesized by a simple solvent evaporation-induced self-assembly method using a nitrogen-containing ionic liquid concurrently as a nitrogen source and mesoporous template. After being evaporated and subsequently calcined at various temperatures (300–900 °C), the synthesized samples were thoroughly characterized by X-ray diffraction (XRD), Raman, small-angle X-ray scattering patterns (SAXS), N₂ adsorption-desorption isotherms, X-ray photoelectron (XPS) and UV–Vis diffuse reflectance (UV–Vis DR) spectroscopies. The obtained results suggest that the calcination temperature greatly influences the crystallization of TiO₂, formation of mesoporous structure, specific surface area and N-doping amounts. Among the fabricated photocatalysts, the samples calcined at 600 °C exhibit superior photocatalytic performance for hydrogen production in water/methanol solution under visible light illumination if compared to other synthesized samples and commercial TiO₂ (Degussa P25). The finding is possibly due to the synergy of more N-doping amounts on the well-defined mesoporous TiO₂ with highly anatase crystal phase and moderate surface area in the catalysts.     

Use of flexible micro-temperature sensor to determine temperature in situ and to simulate a proton exchange membrane fuel cell

In this work, a micro-temperature sensor on a 40 μm flexible stainless-steel substrate was fabricated using micro-electro-mechanical systems (MEMS). Embedding a micro-temperature sensor in a proton exchange membrane fuel cell (PEMFC) to monitor temperature will not damage the sensor during the experimental process. This investigation is the first to develop a micro-temperature sensor that can be placed anywhere between the membrane electrode assembly (MEA) and the flow-channel plate inside a PEMFC. The simulated temperature is consistent with the experimentally determined temperature. The performance curve is also consistent with experimental results, revealing the accuracy of the simulation and the effectiveness of monitoring temperature inside a PEMFC.