S-矩阵猜想的几个特殊情形

利用矩阵分块技术、矩阵Frobenius范数的性质以及矩阵的极分解,对SLOANE等在1976年提出的一个关于〖WTHX〗S〖WTBZ〗\|矩阵的猜想进行了讨论. 对于一些特殊矩阵,这个猜想被证明是成立的.     

两参数Lomax分布形状参数的经验Bayes估计问题

依据经验Bayes(EB)估计的思想方法,研究在平方损失函数下两参数Lomax分布形状参数的EB估计问题。在这种损失函数下,获得了形状参数的Bayes估计,利用密度函数的递归核估计方法构造了相应的EB估计,在适当的条件下证明了所提出的EB估计是渐近最优的,并获得了它的收敛速度。最后给出一个满足文中主要结果的实例。     

贵东岩体X荧光光谱、等离子体质谱分析结果及其对岩体演化的指示意义

粤北贵东岩体是由形成于早侏罗世(燕山一期)的粗粒黑云母花岗岩、晚侏罗世(燕山三期)的中细粒二云母或白云母花岗岩、早白垩世(燕山四期)石英正长岩组成的复式岩体。不同期次花岗岩进行X荧光光谱和等离子体质谱测试结果显示：(1)同期岩体自上而下具有硅碱组分降低,铁镁含量组分和LREE,LREE/HREE及(La/Yb),N值总体升高的变化趋势;(2)复式岩体从早期到晚期,岩体的硅碱组分逐渐升高,而∑REE,LREE/HREE,(La/Yb)_N及δEu值则逐渐降低,稀土配分曲线由右倾型向海鸥型过渡,表明复式岩体的形成是地壳岩石多次原地熔融(重熔)的结果;(3)微量元素组成同样反映复式岩体形成是地壳岩石多次原地熔融(重熔)的结果;多次熔融(重熔)导致晚期岩体U丰度和U/Th比值升高,故该区铀矿床的形成多与燕山晚期的熔融(重熔)事件有关。     

常压下固态KNO2热力学性质的密度泛函理论研究

采用密度泛函理论结合准谐德拜模型研究常压下300~725 K间KNO₂立方结构的热力学性质,重点分析常压下定压热容、定容热容、熵、德拜温度、体膨胀系数、平衡体积和体弹模量随温度的变化.结果显示,常压下计算的定压热容随温度的变化与实验数据符合较好,而计算的熵与实验数据相差较大.计算得到KNO₂的平均体膨胀系数约为1.837 8×10^-5K^-1,常温下(300 K)KNO₂的德拜温度约为667.13K.     

A Lattice Hydrodynamic Model for Traffic Flow Accounting for Driver Anticipation Effect of the Next-Nearest-Neighbor Site

In this paper, a new lattice hydrodynamic model is proposed by incorporating the driver anticipation effect of next-nearest-neighbor site. The linear stability analysis and nonlinear analysis show that the driver anticipation effect of next-nearest-neighbor site can enlarge the stable area of traffic flow. The space can be divided into three regions: stable, metastable, and unstable. Numerical simulation further illuminates that the driver anticipation effect of the next-nearest-neighbor site can stabilize traffic flow in our modified lattice model, which is consistent with the analytical results.     

不同排布方向性椭圆孔液体润滑机械密封性能的研究

为提高液体润滑多孔端面密封的动压性能,提出了方向性多孔端面机械密封.考虑端面间润滑液膜的空化现象,基于质量守恒的JFO空化边界条件建立了理论模型,采用有限差分法求解Reynolds控制方程,获得了端面膜压分布,从而对比分析了方向性椭圆孔的排布方式对多孔端面机械密封性能的影响规律.结果表明:椭圆孔的方向性排布对端面密封的密封性能影响较大,高压侧下游泵送孔可有效提升密封端面的流体动压特性,上游泵送孔不论在高压侧还是在低压侧均可有效降低密封泄漏率;当形状因子γ为3~5,内外孔倾斜角α为35°~45°和β为125°~135°时,可获得最佳的动压性能,当形状因子γ为3~5,倾斜角α为30°~50°和β为30°~50°时,可以获得最低泄漏率.     

Design, Syntheses and Biological Activities of Novel Anthranilic Diamide Insecticides Containing N-Pyridylpyrazole

In search of environmentally benign insecticides with high activity, low toxicity and low residue, a series of novel anthranilic diamide derivatives containing N-pyridylpyrazole was designed and synthesized. All the compounds were characterized by ¹H NMR spectroscopy and elemental analysis. The single crystal structure of compound 8j was determined by X-ray diffraction. The insecticidal activities of the new compounds were evaluated. The results show that some compounds exhibited moderate insecticidal activities against Lepidoptera pests. Among this series of compounds, compounds 8o and 8p showed 100% larvicidal activity against Mythimna separate Walker, Plutella xylostella Linnaeus and Laphygma exigua Hubner at a test concentration of 200 mg/kg, which is equal to the commercial chlorantraniliprole.     

氢气对AlN薄膜择优取向的作用机制

采用脉冲反应磁控溅射方法在Si衬底上沉积了(100)和(002)择优取向的AlN薄膜,随着溅射功率的降低或氢气浓度的增加,放电电压下降,沉积粒子能量降低,薄膜由(002)取向逐渐向(100)取向转变.在溅射气氛中加入氢气后,薄膜中的氧含量降低,表面形貌与表面粗糙度均随着择优取向的改变发生变化.溅射功率及氢气浓度对AlN薄膜择优取向的影响规律表明,氢气主要是通过降低沉积粒子的能量和在衬底表面产生吸附两种作用方式来影响AlN薄膜的择优取向.     

超高效液相色谱-线性离子阱/静电场轨道阱高分辨质谱鉴别纺织品中禁用芳香胺及其异构体

针对目前纺织品中禁用偶氮染料检测中的假阳性问题,建立了一套应用超高效液相色谱-线性离子阱/静电场轨道阱高分辨质谱（UPLC-LTQ/Orbitrap）同时筛选24种禁用芳香胺及其常见的14种异构体的方法。样品经连二亚硫酸钠还原,叔丁基甲醚提取后,以水/甲醇（9/1,v/v）稀释定容,用ZORBAX SB-C₁₈色谱柱（150 mm×2.1 mm,5 μm）分离,以0.1%甲酸水溶液和甲醇为流动相,电喷雾正离子（ESI⁺）模式电离。以准分子离子峰的精确质量数和保留时间定性,以提取的色谱图峰面积定量。38种芳香胺的线性相关系数大于0.99,方法检出限为0.5~5 μg/kg。该方法可通过一次实验同时对24种禁用芳香胺及其常见的14种异构体准确定性定量,大大缩短检测周期,实际样品检测也进一步验证了其灵敏性和准确性。     

Ratiometric Fluorescent Probe Based on Novel Red-emission BODIPY for Determination of Bovine Serum Albumin

A novel red-emission boron-dipyrromethene（BODIPY） dye with a pyrrole ring was synthesized simply via one-pot reaction. The spectral properties of it were investigated under the conditions of different solvents. The results show that the as-prepared BODIPY dye is extremely sensitive to solvent polarity, and the fluorescent emission enhances with the decrease of solvent polarity. In aqueous buffer, the addition of bovine serum albumin leads to a ratiometric change in absorption spectra with an association constant of 1.16×10^6 L/mol. Meanwhile, the fluorescence emission increases greatly at 622 nm but changes slightly at 575 nm. The response time is very short（less than 3 min）, and the changes of color can be noticed by naked eyes. Bovine serum albumin can be detected by this ratiometric fluorescence probe, but other proteins or enzymes cannot be detected by this method, which indicates that this novel dye has high selectivity towards bovine serum albumin. The reason is that bovine serum albumin has suitable hydro- phobic cavities for binding with the dye. In addition, the dye molecule can penetrate cell membrane easily and make a fast fluorescent stain, which makes it a potential probe for living-cell fluorescence imaging.