4种等温物态方程适用性的比较研究

 通过分析现有文献,认为4种两参数的物态方程在高压物理研究中较为流行,它们是Vinet、Baonza、Morse和Born-Meyer（BM）方程。将这4种方程用于拟合50种材料的实验压缩数据,得出了零压下压缩模量及其一阶压力导数的优化取值,并计算了4种方程的平均压力误差。结果表明,Morse方程的精度最高,对50种材料的平均拟合误差为0.557 6%;BM方程次之,平均误差为0.615 1%;Vinet和Baonza方程的误差大一些,分别为0.788 9%和0.833 3%。对8种典型材料计算了压力误差随压强变化的曲线,所得结果与平均误差的趋势一致,也是Morse方程的精度最高。在宽广压力范围的高压物态方程研究中,推荐使用Morse方程。     

New exact solutions of nonlinear conformable time-fractional Boussinesq equations using the modified Kudryashov method

In this paper, the nonlinear Boussinesq equations with the conformable time-fractional derivative are solved analytically using the well-established modified Kudryashov method. As a consequence, a number of new exact solutions for this type of equations are formally derived. It is believed that the method is one of the most effective techniques for extracting new exact solutions of nonlinear fractional differential equations.     

DNA damage induced by laser-hematoporphyrin derivative

Irradiation caused DNA single-strand breaks in S180 cells in the presence oflaser-hematoporphyrin derivative(HPD).The number of single strand breaks was 3.69 ×10~(10)break dolton~(-1).The analysis of base composition of DNA showed that the effect of laser-HPDirradiation on guanine was the highest,being 5-12 times as high as those of the three others(adenine,cytosine and thymine).It was different from the nature of DNA damage caused by γ-ray irradiation.     

Analytical approximate solution for nonlinear space-time fractional Klein Gordon equation

The fractional derivatives in the sense of Caputo and the homotopy analysis method are used to construct an approximate solution for the nonlinear space-time fractional derivatives Klein-Gordon equation. The numerical results show that the approaches are easy to implement and accurate when applied to the nonlinear space-time fractional derivatives KleinGordon equation. This method introduces a promising tool for solving many space-time fractional partial differential equations. This method is efficient and powerful in solving wide classes of nonlinear evolution fractional order equations.     

夫勒烯二氮杂桥衍生物对吡啶荧光猝灭机制以及它的电化学的研究

用荧光光谱研究了富勒烯二氮杂桥衍生物(eddy2)对吡啶荧光的猝灭机制,发现吡啶在426.27 nm处有荧光发射峰,当向吡啶中分别加入C₆₀和eddy2时,原有的发射峰强度明显减弱,且向短波长稍有移位,C₆₀和eddy2对吡啶荧光有猝灭作用。吡啶-C60和吡啶-eddy2体系的猝灭过程是分子之间结合形成了复合物引起的静态猝灭。eddy2对吡啶的离解常数为K_D＝2.28×10-6 (mol·L-1),结合常数K_S＝4.39×10-5 (L·mol-1)。同时研究了eddy2的电化学行为,发现eddy2的前3个还原峰电位比母体C₆₀的峰电位正移,表明eddy2的电化学还原比C₆₀的电化学还原容易,更容易接收电子。     

Does the flatness of the velocity derivative blow up at a finite Reynolds number?

A tentative suggestion is made that the flatness of the velocity derivative could reach an infinite value at finite (though very large) Reynolds number, with possible implications for the singularities of the Navier—Stokes equations. A direct test of this suggestion requires measurements at Reynolds numbers presently outside the experimental capacity, so an alternative suggestion that can be tested at accessible Reynolds numbers is also made.     

基于线性回归算法的春玉米叶面积指数的冠层高光谱反演研究

利用辽宁锦州地区2013年生长季不同土壤水分控制条件下的春玉米冠层高光谱数据,及对应的植株叶面积指数(leaf area index,LAI)数据,分析在不同发育期内不同生长状况下的春玉米冠层高光谱特征及其与植株叶面积指数的关系。采集并计算共313组有效样本,包括350～2 500 nm波段范围光谱的反射率、反射率倒数的对数、反射率一阶导数及LAI,应用多元逐步线性回归法和偏最小二乘回归法,对剔除了受大气水分影响较为严重光谱波段的其他波段数据进行降维,构建叶面积指数的全波段冠层高光谱数据模型,并进行精度检验与比较。结果表明,春玉米LAI与光谱反射率在可见光波段(350～680 nm)、红外波段(1 430～1 800和1 950～2 450 nm)均呈显著的负相关;反射率倒数的对数在对应区间为显著的正相关;反射率一阶导数则在可见光和近红外波段(350～1 350 nm)存在较显著相关波段。三种全波段冠层高光谱数据在春玉米LAI的线性回归中,偏最小二乘法在以冠层反射率为自变量的模型构建中,比多元逐步线性回归拟合度好,其总均方根误差为0.480 7;以冠层光谱反射率的倒数的对数及一阶导数为自变量,应用逐步线性回归法建模,拟合度较好,其总均方根误差分别为0.333 5和0.348 8;三种光谱数据的春玉米LAI两种回归算法中,以冠层反射率倒数的对数为自变量,应用逐步线性回归方法建模的拟合度最佳。     

不同滞尘量对城市植物冠层光谱的影响

为了探索不同滞尘量对植被冠层光谱的影响,以位于上海市中心城区的上海师范大学徐汇区校园为研究样区,选取并使用ASD FieldSpec 3地物光谱仪测定校园内龙爪槐、紫荆、红叶石楠及蔓长春等植物不同滞尘量等级下的冠层反射光谱,然后在实验室中使用万分之一电子分析天平测定相应植物的滞尘量并计算各植物的滞尘能力。在此基础上,分析不同滞尘量对植物冠层光谱特征变化的影响。结果表明： (1)植物在710～1 350 nm之间光谱反射率会随着滞尘量的增减而减小而且三条曲线之间的差值较大;滞尘量的变化对各植物在350～710和1 450～1 750 nm之间的光谱影响较复杂,三条曲线之间的差值虽小但差值比并不小。(2)滞尘对植物冠层光谱的影响不仅与滞尘量有关还与树种有关,不同植物或同种植物不同波长的光谱曲线对滞尘量的灵敏度不同。(3)各植物在“绿峰”和红边附近的光谱曲线的斜率会随着滞尘量的增加而减小。(4)滞尘不会引起红边位移现象,但会消弱红边一阶导数的“双峰”现象,表现为“主峰”值与“次峰”值之间的差随着滞尘量的增加而减小,红边位于719 nm处。找到滞尘或不同滞尘量对植被冠层光谱的影响关系,对高光谱遥感在这一领域的应用具有重大意义。     

Proton conductivity of phosphoric acid derivative of fullerene

The proton conductive property of methano [60] fullerene diphosphoric acid has been investigated under various humidity conditions at the temperature range between 15 and 45 °C. It shows proton conductivity as high as 10⁻² S cm⁻¹ at 25 °C under relative humidity of 95%. Thermal analyses including TG–DTA and thermal desorption mass spectroscopy (TDS) confirm that the compound is thermally stable up to 200 °C. Proton conduction of the compound depends very much on humidity or water content. The logarithmic conductivity at 25 °C is increased linearly with increasing relative humidity. The activation energy (E_a) estimated from the slope of log(σT) vs. 1/T is decreased from 1.08 to 0.52 eV, as the relative humidity is increased from 40% to 75%. The humidity dependence of conductivity is discussed in the light of the observed hydration isotherm.     

2,3-二羟基萘钼多酸有机衍生物的合成及1H NMR和IR谱学研究

本文对二种新合成的2，3－二羟基萘二钼和四钼多酸有机衍生物[n-Bu)4N]2[Mo2O5(OC10H6O)2](Ⅰ）和[n-Bu)4N]2[Mo4O10(OC10H6O)2(OCH3)2](Ⅱ)进行了红外光谱与核磁共振波谱研究，发现[Mo2O5]^2 中钼氧多桥键的红外振动频率较[Mo4O10(OCH3)2]^2 中钼氧多桥键的红外振动频率红移，而在配合物Ⅱ中2，3－二羟基中芳环的^1H化学位移较配合物Ⅰ中向低场移动。同时还发现含二钼配位中心[Mo2O5]^2 的[Mo2O5(OC10H6O)2]^2-与含四钼配位中心[Mo4O10(OCH3)2]^2 的[Mo4O10(OC10H6O)2(OCH3)2]^2-生成条件的差异仅仅只在反应体系的pH值的微小变化，说明钼多酸有机衍生物阴离子是对体系酸碱度极为敏感的物质。