基于课程表的智能分析回溯算法的研究

用回溯算法解决排课问题是目前排课软件最为常用的算法,但有很多弊端.为了使得到的课表符合硬、软件约束,并具有较高的适应度,在运用回溯算法进行排课时,我们在进行分配的过程中引入评价机制,确保每一步都是比较优化的选择,从而使整个排课结果也比较优化,实现评价机制的关键是编码和对应的适应度评价的函数.     

加权Baouendi-Grushin型算子的基本解与一类加权Hardy不等式(英文)

In this paper we obtain the fundamental solution for a class of weighted BaouendiGrushin type operator L_p,γ,αu = ▽_γ·(|▽_γu|^p-2ρ^α▽_γu) on R^m+n with singularity at the origin,where ▽_γ is the gradient operator defined by ▽_γ =（▽_x,|x|^γ▽_y） and ρ is the distance function.As an application,we get some Hardy type inequalities associated with ▽_γ.     

POLYMER BOUND PYRROLE COMPOUNDS–VI. PHOTOPHYSICAL PROPERTIES OF MONOMERIC MODELS FOR POLYSTYRENE-BOUND PORPHYRINS

Abstract— Several porphyrin esters used as models for polystyrene-bound porphyrins have been prepared and their excited states have been studied by laser flash photolysis, IR phosphorescence of singlet molecular oxygen, O₂(¹Δ_g), and steady-state fluorescence. The photophysical properties of the porphyrin esters in solution are affected by the presence of nitro group(s) in the chain. In this case, an important decrease in φ_f, φ_T and φ_δ (to ca 0.7–0.4 of the value for the parent dimethyl ester) is observed. This is mainly due to intramolecular electron-transfer quenching [by the nitro group(s)] of the first excited singlet state of the porphyrin. The thermodynamic feasibility of this deactivation pathway has been confirmed polarographically. Quenching of the porphyrin triplet state and of O₂(¹Δ_g) by the nitro groups is negligible. The present conclusions explain also the results obtained previously for the photooxidation of bilirubin sensitized by the parent insoluble polystyrene-bound porphyrins. In that case the photooxidation rates were correlated directly with the quantum yield of O₂(¹Δ_g) production by the sensitizer. The consequences of these results for the use of polystyrene-bound porphyrins in sensitized photooxidation processes are discussed.     

ADJACENCY PRESERVING MAPS ON THE SPACE OF SELF-ADJOINT OPERATORS

§1. Introduction and Statement of ResultsThe study of the geometry of matrices was initiated by Hua [11–18] in the middle oftwenty century. In this geometry, the points of the space are a certain kind of matricesof a given size (rectangular matrices, symmetric matrices, Hermitian matrices, etc.). Witheach such space of matrices, we associate a group of motions. The main problem is tocharacterize this group by a geometric invariant called adjacency (see [23]). Recently, someauthors have gen…     

车载多传感器集成系统中线阵相机的检校方法及数据分析

传感器检校是车载多传感器集成系统中不可缺少的重要环节。介绍了一种线阵相机的数学标定方法,根据该方法设计了相关的检校设备及检校坐标系。通过对不同条件下的试验数据对比,获取最佳的实验条件和该方法所需的基本参数,并采集最佳试验条件下的试验数据,通过对数据进行处理得到投影中心坐标,对可能影响检测结果的多种实验因素进行了分析,将受这些因素影响较小的数据作为有效数据来解算最终的实验结果,可以得到较精确的结果。     

第1届亚洲物理奥林匹克竞赛力学实验题解答及分析

介绍第1届亚洲物理奥林匹克竞赛力学实验题及其解答,并分析了该实验题的设计思想、特点与要求.     

一类小波的构造

给出基于自相似形定义于无界集的多元小波构造方法,利用此方法,可以构造非张量积形式的多元小波.     

火炮用PCrMo钢激光熔覆MoS2润滑涂层摩擦学性能研究

PCrMo钢是导致火炮系统故障的磨损失效零部件主要材料.为了提高零部件的寿命,将固体润滑技术引入火炮抗磨减磨设计中.选取8 ～ 10 μm和3～5 μm两种粒度下二硫化钼作为固体润滑材料,采用激光熔覆工艺在PCrMo钢试样表面制备润滑涂层.通过对涂层宏观性能表征,发现粒度小的涂层熔覆厚度较好;采用扫描电镜和能谱仪分别对涂层表面、剖面微观形貌和化学成分进行分析,发现涂层表面有凹坑产生,且凹坑中氧的含量明显高于光滑表面;涂层剖面与基体结合处存在一定的缝隙,涂层元素与基体元素发生了熔渗.进一步开展的摩擦磨损试验表明:与PCrMo钢裸基材试样相比,两种粒度下润滑涂层试样摩擦系数和磨损量皆降低,磨损量分别为14.84％和42.01％,其中大粒度下涂层摩擦性能较优.二硫化钼润滑涂层起到了很好的润滑效果,可以作为火炮磨损零部件减磨的有效手段.     

吡啶-2,6-二甲酸氢钾的合成、结构表征及热化学性质

合成了吡啶-2,6-二甲酸氢钾(KHDPC). 利用X射线单晶衍射仪确定了化合物的晶体结构. 用精密自动绝热热量计测量了其在78~360 K温度区间的低温热容. 利用最小二乘法对配合物的实验热容进行拟合, 得到热容随温度变化的多项式方程. 利用此方程计算出温度区间内的舒平热容值及相对于298.15 K时的热力学函数值. 利用Hess定律设计合理的热化学循环, 在等温环境下利用溶解-反应热量计分别测定所设计热化学反应的反应物和产物在所选溶剂中的溶解焓并计算出反应的反应焓. 最后, 计算出该化合物的标准摩尔生成焓为-(1052.69±1.52) kJ/mol.