求解参数识别反问题的同伦正则化方法

提出了求解参数识别反问题的同伦正则化方法,给出了相应的收敛性定理.数值结果表明该方法是一种快速的大范围收敛方法.     

Inhibitory Effect and Mechanism of Chitosan–Ag Complex Hydrogel on Fungal Disease in Grape

Hydrogel antibacterial agent is an ideal antibacterial material because of its ability to diffuse antibacterial molecules into the decayed area by providing a suitable microenvironment and acting as a protective barrier on the decay interface. The biocompatibility and biodegradation make the removal process easy and it is already widely used in medical fields. However, there have been few reports on its application for controlling postharvest diseases in fruit. In this study, the Chitosan–silver (CS–Ag) complex hydrogels were prepared using the physical crosslinking method, which is used for controlling postharvest diseases in grape. The prepared hydrogels were stable for a long period at room temperature. The structure and surface morphology of CS–Ag composite hydrogels were characterized by UV-Vis, FTIR, SEM, and XRD. The inhibitory effects of CS–Ag hydrogel on disease in grape caused by P. expansum, A. niger, and B. cinerea were investigated both in vivo and in vitro. The remarkable antibacterial activity of CS–Ag hydrogels was mainly due to the combined antibacterial and antioxidant effects of CS and Ag. Preservation tests showed that the CS–Ag hydrogel had positive fresh-keeping effect. This revealed that CS–Ag hydrogels can play a critical role in controlling fungal disease in grapes.     

环保节水型冷却塔的研究

综合湿式冷却塔有热交换效率高且造价低而空气冷却器无水蒸发等特点,提出了环保节水型冷却塔.对该新型塔进行了理论分析,对塔内换热、气动力性能等进行了数值计算,对塔内空气换热器和填料层间的冷却负荷以及与风机性能等进行了耦合匹配,结合北方气候条件的计算分析表明新型塔确有良好的节水和环保效果.     

纤维素热解过程中活性纤维素的生成研究

热重分析发现活性纤维素的生成始于530 K左右,对应于失重图上的肩部及SDTA曲线中强烈的放热峰.在辐射加热闪速热裂解试验台上获取了一种可溶于水、高温下易分解、室温下呈固态且稳定存在的黄色中间产物.扫描电镜图片证明在热裂解初期纤维素经历了一个熔化和相互粘结的状态,产物的红外谱图证实了大量的羰基和羧基官能团的生成.高效液相色谱分析证明其主要成分是一系列聚合度不同的低聚糖,推断该低聚糖即为活性纤维素.     

单轴拉伸下氧化锆纳米柱相变机理的分子动力学研究

通过分子动力学模拟,观察到[001]取向的四方氧化锆纳米柱在拉伸载荷下具有两个线弹性变形的应力-应变关系.这一现象是四方结构向单斜结构相变的结果 .为了进一步阐明应力-应变曲线,进行了包括晶体结构分析和原子应变计算在内的详细研究.晶格取向强烈影响塑性变形机制,即[001]和[111]取向的纳米柱在拉伸载荷下经历相变,而沿[110]取向的纳米柱导致脆性断裂.观察到显著的温度效应,随着温度从300K升高到1500K,弹性模量从573.45GPa线性降低到482.65GPa.此外,还用轻推弹性带(NEB)理论估算了相变能垒,观察到相变能垒随温度的升高而降低.这一工作将有助于加深对氧化锆的四方相到单斜相转变和纳米尺度力学行为的理解.     

催化动力学光度法测定槲皮素

在稀硫酸介质中,槲皮素对KBrO3氧化甲基红褪色反应有明显的催化作用。研究了该反应的最佳条件,建立了测定槲皮素的催化动力学光度法。当甲基红、硫酸、KBrO3的用量分别为0.70 mL、0.30 mL、0.25 mL,反应温度80℃,反应时间8 min时,该法测定槲皮素的线性范围为0.0~0.05 mg/L,检出限为0.002 mg/L。方法用于银杏叶和中草药鱼腥草中槲皮素含量的测定,结果满意。     

Phenomenological studies on B~0 → [K~-π~+]_(S/V)[π~+π~-]_(V/S) → K~-π~+π~+π~- decay

Within the quasi-two-body decay model,we study the localized CP violation and branching fraction of the four-body decay B~0→[K~-π~+]_(s/V)[π~+π~-]_(V/)S→K-π~+π~-π~+ when the K~-π~+and π~-π~+ pair invariant masses are0.35 m(K~-π~+)2.04 GeV and 0 mπ~-π~+1.06 GeV,with the pairs being dominated by the K_0~*(700)~0,K~*(892)~0,K~*(1410)~0,K_0~*(1430) and K~*(1680)~0,and fo(500),ρ~0(770),ω(782) and fo(980) resonances,respectively.When dealing with the dynamical functions of these resonances,fo(500),ρ~0(770),fo(980) and K_0~*(1430) are modeled with the Bugg model,Gounaris-Sakurai function,Flatte formalism and LASS lineshape,respectively,while the others are described by the relativistic Breit-Wigner function.Adopting the end point divergence parameters ρA ∈[0,0.5] andΦ_A∈[0,2π],our predicted results are F_(CP)(B~0→K~-π~+π~+π~-)∈[-0.365,0.447] and B(B~0→K-π~+π~+π~-)∈[6.11,185.32] x 10~(-8),based on the hypothetical qq structures for the scalar mesons in the QCD factorization approach.Meanwhile,we calculate the CP violating asymmetries and branching fractions of the two-body decays B~0→SV(VS) and all the individual four-body decays B~0→SV(VS)→K~-π~+π~-π~+,respectively.Our theoretical results for the two-body decays B~0→K~*(892)~0 fo(980),B~0→K_0~*(1430)~0ω(782),B~0→K~*(892)~0 f~0(980),B~0→K_0~*(1430)~0ρ,and B~0→(1430)~0ω are consistent with the available experimental data,with the remaining predictions await testing in future high precision experiments.     

The Link between Stochastic Differential Equations with Non-Markovian Coefficients and Backward Stochastic Partial Differential Equations

In this paper, we conjecture and prove the link between stochastic differential equations with non-Markovian coefficients and nonlinear parabolic backward stochastic partial differential equations, which is an extension of such kind of link in Markovian framework to non-Markovian framework.Different from Markovian framework, where the corresponding partial differential equation is deterministic, the backward stochastic partial differential equation here has a pair of adapted solutions, and thus the link has a much different form. Moreover, two examples are given to demonstrate the applications of the derived link.     

Zinc Stannate Nanostructures for Energy Conversion

To date,ternary metal oxide semiconductor materials have attracted extensive attention worldwide due to their unique optoelectronic properties.As a classical ternary oxide,Zn2SnO4 is featured with the high electron mobility,wide band gap,negligible visible light absorption and tailorable electronic band structures.Thus,it is an ideal material for practical use in solar cells,lithium batteries,sensors,and photo-catalysts.In this review,we summarize the recent research progress of this material with the focus on the synthesis methods,nanostructures,and the resulting effects on the crystal structure,optical properties,and photoelectrochemical properties.Moreover,their potential applications in different devices are highlighted and carefully discussed.     

类晶加合物(M=Co,Cu, Ni)的晶体结构及分子间相互作用的理论研究

合成了3种化合物 [2-ClPyH]2CoCl4(1), [2-ClPyH]2NiCl4(2)和[2-ClPyH]2CuCl4(3), 单晶X射线衍射法晶体结构测定结果表明, 这3种化合物是同形加合物, 在它们的结构中, [2-ClPyH]+离子呈平面状, 而[MCl4]2-离子为变形的四面体. 晶体结构分析发现晶体中存在N—H…Cl和C—H…Cl氢键, 以及Cl…Cl分子间相互作用和π-π堆积作用. 对自由状态下独立的配位离子进行的几何构型优化, 以及三维周期性条件下几何结构优化的量子化学计算结果表明, 标题化合物中具有方向性和选择性的氢键决定延伸性结构的方向, 而相对较弱的卤素…卤素作用在最终晶体结构的确定中扮演很重要的角色.