固定节面量子MonteCarlo的一个新算法

提出了一个固定节面量子MOnTECArlO的新算法,与前人的算法相比,其“指导函数”的优化不是在扩散前,而是在扩散过程中同步进行;这不仅在机时上是节省的,更重要的是优化与扩散两者按相同的取样方式进行,达到互相改善的目的;这一优化方案是超线性收敛的,它能加快粒子的扩散;在扩散过程中,“指导函数”的节面不断发生改变,这有利于减小“固定节面误差”.这一新算法已被运用到CH_2的X--3b_1态和A--1A_1态,以及nH_2的π-X--2b_1态和σ-A--2A_1态总能量的计算,由此算出了CH_2单一三重态的“劈开”能△E_(S-T)=(45.542±1.840)kJ/MOl和nH_2的σ-π“劈开”能△E_(σ-π)=(141.644±1.589)kJ/MOl.计算结果表明这一新算法在精度、统计误差和计算量方面比一般固定节面量子MOnTECArlO方法都要优越得多

Study on Highway Road Detection Based on Computer Vision

根据高速公路路面的基本特征,通过分道线特征点投影位置的计算,提取出了比较完整的当前车道分道线特征点。建立道路边缘灰度模型,采用gAbOr变换多分辨率的特点,对图像按方向进行滤波处理,实现道路边缘线检测和拟合。实验结果表明,所讨论的方法在工程实践中有实际应用价值。According to the basic characteristics of the road and through marginal extraction,the location of current lane line can be acquired.After calculating projection location of the lane feature points,feature points of a relatively complete current lane dividers can be distilled.Establishing the model of road edge grey scale and adopting the multi-resolution characteristics of Gabor transform,they can filter the image so that they can realize the detection and fitting of the road edge line.Experimental results show us that the method discussed in this text has a certain value in practice.福建省青年科技人才创新项目(2006F3121

Hartree-Fock量子MonteCarlo方法

量子MOnTECArlO(QMC)方法已成功地应用于量子化学领域,对QMC的评述请参考

Corrosion Characteristics of Electrodeposited Ni Mo P Alloy Immersed in NaCl Solution

用失重法、阳极极化曲线、Ｘ光电子能谱（ＸＰＳ）以及俄歇电子能谱（ＡＥＳ）研究了电沉积ＮｉＭｏＰ合金镀层在５％ＮａＣｌ溶液中的腐蚀特性．非晶态ＮｉＭｏＰ合金镀层比晶态ＮｉＭｏＰ合金镀层有较低的腐蚀速度．阳极极化曲线表明，ＮｉＭｏＰ合金镀层中，镍的摩尔分数为０．７１９～０．８６８时，随镀层中磷含量的增加，腐蚀电位正移；而活化区的峰电流随镀层中钼含量的增加而增加．磷含量对活化区的峰电流以及钼含量对腐蚀电位的影响均很小．ＸＰＳ和ＡＥＳ分析指出，经５％ＮａＣｌ溶液中浸渍后，ＮｉＭｏＰ合金镀层表面形成厚度约为５０ｎｍ的氧化膜．这层氧化膜主要由Ｎｉ２Ｏ３，ＭｏＯ３和ＰＯ４３－等构成，其在电解质溶液和合金间起着阻挡层的作用．The corrosion characteristics of electrodeposited Ni Mo P alloy immersed in 5wt.% NaCl solution were investigated using immersion, anodic polarization curves, XPS and AES analysis. The corrosion rates of amorphous Ni Mo P alloys are lower than that of crystalline Ni Mo P alloys. Anodic polarization curve experiments show that for the electrodeposited Ni Mo P alloys, the nickel mol fraction of which has in between 0.719 and 0.868, the corrosion potential moves to positive with the increase of P content, and the peak current value of active region increase with the increase of Mo content in alloys, though the effects of P content on the peak current of active region and of Mo content on the corrosion potential are insignificant. XPS and AES analyses indicate that after immersion in 5wt.% NaCl solution, an oxidation film of about 50 nm in thickness is formed on the surface of Ni Mo P alloys. This oxidation film is composed of Ni 2O 3,MoO 3 and PO 3- 4, and acts as a barrier between the alloy and the electrolyte.作者联系地址：湖南师范大学化学系,天津大学应用化学系Author's Address: Department of Chemistry, Hunan Normal University, Changsha, Hunan, 410006 Yao Suwei Guo Hetong Department of Applied Chemistry, Tiangjin University, Tianjin, 30007

Variational Monte Carlo Treatment of Molecules

对变分量子MOnTECArTO方法提出了一种新算法：将传统的HArTrEE-fOEk方法与量子MOnTECArlO方法有机结合在一起；导出了“局部能”的解析式；使用了一种新的分子相关函数和新的随机数发生器。我们用这个新算法计算了H2、lIH、lI2、H2O、f2分子的基态和CH2分子的3b1、1A1态的能量.计算结果表明，这个新算法在精度和统计误差两个方面比一般VMC过程都要好得多.A novel algorithm is outlined For the variational quantum Monte Carlo treatment of molecules.The quantum Monte Carlo method is combined organically with the conventional Hartree-Fock method in the algorithm.An analytical expression of the local energy is presented.A new Form of trial waveFunction and a new generator of random numbers is also used.This new algorithm is used to compute the energies of the ground states For molecules H2, LiH, Li2, H2O,F2 and the states X3B1 and a1A1 of CH2, and calculated results show that this novel algorithm.is much superior to the usual VMC in both accuracy and statistical error.湖南省教委科研基

Research on Anti-collision Safe Running of Vehicle on Highway

为了提高在高速行驶状态下的车辆主动安全性能,并针对高速公路上汽车追尾事故发生的特点,以汽车制动过程为分析基础,得到3种不同的安全车距计算方法.利用MATlAb对干燥路面状况下的车速与安全车距的关系进行仿真.仿真结果表明,其符合国家对机动车运行安全的要求.在此基础上,研究了汽车防追尾安全行驶的控制与执行,最后提出了基于不同影响因子的安全车距等级预警方法.To improve initiative security of vehicle at high speed,according to the characteristics of the accident of highway vehicle,three different safe vehicle gap can be obtained on the basis of the analysis of a vehicle braking process.It can be emulated by using matlab so as to understand fully the relationship between vehicle speed and safe gap at dry road conditions.The simulation results show that the safe running requirement of the vehicle can be acquired.And then the process of the control and implementation of safe running was investigated.Finally the method of warning of safe vehicle gap was advanced based on the level of security of the proposed factor

Surplus Function Quantum Monte Carlo Approach

为量子MOnTECArlO方法提出一条新途径──剩余函数法；引入了SCHrOdIngEr方程剩余函数的概念，利用剩余函数将一种新的有明显物理意义的试探函数应用到量子MOnTECArlO过程中；这种试探函数是通过一种迭进式的方式确定的，它不需要在MOnTECArlO过程中优化参数.文中我们将给出这种试探函数的具体形式，证明由这种试探函数求出的能量期望值收敛于体系真实的能量值；文中还给出这种试探函数能量期望值的计算公式以及它在变分MOnTECArlO过程中的具体运算步骤；几个分子的算例说明这种试探函数的能量期望值不仅逐步逼近体系真实的能量值，而且逼近速度也非常快，一般只需要4~5次迭进即可获得90%以上的相关能.据作者所知，这种试探函数的计算精度和收敛速度在目前量子MOnTECArlO方法中均是最高的.A concept of surplus function for Schrodinger equation is put forward.A novel quantum Monte Carlo approach entitled surplus function method is suggested with use of a novel trial function of significant physical meaning which is based on the proposed surplus function.The trial function is of an iteration-type and suffers no time-consuming parameter optimum in a quantum Monte Carlo process.It is theoretically proved that the energy expectation value obtained from the proposed trial function converges to the exact energy value of the system inveshgated.In addition,computation formulas and procedures for energy expectation value are presented.Calculations for several molecules indicate that the energy expectation value obtained from the trial function does converge to the exact energy value of the investigated system and the converging rate is very fast as generally only 4-5 iterations achieves over 90% correlation energy.To our knowledge, both the calculating precision and converging rate of the trial function proposed are the highest one in the quantum Monte Carlo approach at present time.国家自然科学基金;湖南省教委科研基

Differential Diffusion Quantum Monte Carlo Method

提出了自优化扩散量子 MOnTE CArlO差值法 ,这是一个集优化、扩散和相关取样三项技术于一身的 MOnTE CArlO新算法 .这个算法能够在扩散过程中直接计算两个体系之间的能量差 ,且使计算结果的统计误差达到 10 -5HArTrEE数量级 ,获得相关能达 80 %以上 .应用该方法研究分子势能面 ,使用“刚性移动”模型 ,利用 JACObI变换使分子两个几何构型的能量计算具有很好的正相关性 ,因而能得到准确的能量差值和分子势能面 .另外 ,我们还首创了“平衡后留样”技术 ,可节省 50 %以上的计算量 .该算法还可应用于分子光谱、化学反应能量变化值等领域的研究A differential approach for self optimizing diffusion quantum Monte Carlo calculation was proposed in this paper, which is a new algorithm combining with three techniques such as optimizing, diffusion and correlation sampling.This method can directly be used to calculate the energy differential between two systems in the diffusion process, make the statistical error of calculation reduce to the order of 10 -5 hartree, and recover about more than 80% of the correlation energy.We employed this approach to set up a potential energy surface of a molecule, used a "rigid move" model, and utilized Jacobi transformation to make energy calculation for two configurations of a molecule have a good positive correlation.So, an accurate energy differential could be obtained, and the potential energy surface with a good quality can be depicted.In the calculation, a technique called "post equilibrium remaining sample" was set up firstly, which can save about 50% of computation expense.This novel algorithm can also be applied to studying other related fields such as molecular spectroscopy and the energy variation in chemical reactions.国家自然科学基金!(批准号:29773036);湖南省教委科研基金资助课