以＂公＂＂忠＂精神，＂诚＂＂敬＂品质，养＂和协＂校风——教育家汤茂如、王崇阶在成都列五中学期间的办学理念及实践探讨

汤茂如先生是我国三十年代著名的平民教育家，著名的“定县乡村平民教育”实验的组织者和参与者，也是著名教育家晏阳初先生的好友和同志。1940年至1943年期间受四川省政府委聘担任四川省立华阳中学（成都列五中学前身）校长，进行六年一贯制试验。其目的是“增进教育效率，提高教育程度”，“为升大专之青年培植良好基础”。本此，汤茂如大刀阔斧的改革课程，提出了一系列改革主张。其要旨是：培养“公”“忠”“诚”“敬”之品质，树“和协”之校风，重视礼节，陶冶品行，爱生如子，重视学法指导，鼓励学生自修讨论，提倡生活即教学，“知行合一”，培养学生“有工农之身手”等。王誊阶先生之继任校长后，继续贯彻了这些主张，加大改革实验力度，推进学校课制改革。当时学校风气为之走振，声誉为之远扬，成为列五中学历史上最为辉煌的一笔。

拖网选择性对鱼类表型性状的选择作用研究

参照渔业生物学、渔业资源解析学、数量遗传学等有关理论模型,并应用数值模拟方法,对长期选择性捕捞(重点为渔具选择性)是否参与造成了渔业资源的生物学变化(体长、性成熟等)进行某些基础性探索。设计了一个具有一定体长遗传特征的模拟鱼类种群,并利用一种具有固定选择性参数的拖网对其进行长期捕捞。结果表明,多年的持续的捕捞压力使得模拟种群中鱼类体长逐渐减小,减小的幅度随开发率的增大而增大,而终止捕捞后种群的体长并没有发生恢复的迹象,说明这种变化很可能伴随种群遗传的变化,具有自然不可逆性。

新中国50年区域经济发展战略分析

建国以来 ,我国的区域经济发展战略经历了计划经济型的向内地倾斜战略到双轨制型的向沿海倾斜战略的转变 ;前者未能实现效益与均衡的统一 ,后者则使我国经济发展的地区差距越来越大。经过 2 0年的改革开放 。

单基地互质MIMO阵列DOA估计

针对传统均匀直线阵列的相干目标波达方向估计算法的自由度受限于实际阵列阵元数目的问题,提出基于MUSIC算法的单基地发射/接收和协阵列DOA估计方法。该方法将互质MIMO阵列虚拟成等效的和协阵列,找到和协阵列中的连续子阵和半连续子阵,并运用多频操作填补半连续子阵中的孔洞,使之与连续子阵形成一个更长的新连续子阵;然后通过矩阵重构算法解相干,该方法极大地提高了算法的自由度,可以根据目标的个数灵活调整虚拟发射/接收阵元的数量,使复杂度尽可能降低。但该方法涉及到高维矩阵的特征值分解,复杂度仍然很高,因此文中引入传播算子,提出基于传播算子的单基地发射/接收和协阵列DOA估计方法,避免了特征值分解,复杂度得到极大改善。仿真结果证明,该方法对非相干目标的估计能力与前者接近,可用于估计非相干目标以及估计相干目标的大致方向或者判断此时是否有相干目标出现。

随机变量之间相依性的有关研究

随着copulas理论知识的完善,copulas用于相依性的研究也越来越多,从随机变量单调变换的角度出发,给出了在随机变量单调变换的情况下,它们之间的相依性以及相关性所发生的变化,进一步挖掘了copulas在相依性研究中的运用.

室内环境中的色彩设计

在室内环境设计中色彩就是灵魂。室内的色彩对室内设计的空间感、舒适度、环境气氛、使用效率,对人的生理和心理均有很大的影响。

甘肃省城乡居民收入差距实证分析:1979—2009

选取甘肃省1979-2009年的城乡二元结构系数、城市化水平、第一产业总产值占三大产业的比重、农村生产资料价格指数和农村固定投资占全社会固定投资比例等5个指标,利用多元回归模型对甘肃省基尼系数及五个指标进行回归分析,并进行单位根和协整检验,结果表明二元结构系数对基尼系数的影响最大,其次为城市化水平和第一产业总产值占三大产业比例。

巴丹吉林沙漠东南部沙山群地区近地层湍流特征研究

利用巴丹吉林沙漠东南部沙山群地区涡度相关系统观测近到地层湍流资料,计算并统计了湍流方差特征,分析了湍流能谱和协谱变化特点,并讨论了湍流谱局地各向同性。结果表明:三维风速标准差与稳定度关系满足MoninObukov相似理论,温度和湿度(水汽)标准方差与稳定度的关系难以符合Monin-Obukov相似理论;Monin-Obukov相似理论对湍流能谱和协谱的基本能适用,但个别能谱存在差异;局地各向同性理论同样满足。本研究能为复杂地形下近地层湍流物质和能量输送机制提供参考。

从供方管理看到强大的内部执行力

供方是企业生存和发展的一支有生力量，某企业用强化内部执行力，落实对供方的有效管理。从文件对供方的平等要求入手；用执行力和协感染合作方；用领导用严格管理与爱护员工圆融执行力。实现采购过程的严格控制，保证与合格的合作方建立长期合作关系，共同为顾客提供优质产品和服务。

浅谈数学美及其教育教学意义

在归纳总结著名数学家,哲学家对数学美感体硷和论述的基础上,论述了数学科学中确实存在着美,揭示出数学美的教育教学意义.

A Robust Collaborative Recommendation Algorithm Based on k-distance and Tukey M-estimator

The existing collaborative recommendation algorithms have lower robustness against shilling attacks.With this problem in mind,in this paper we propose a robust collaborative recommendation algorithm based on k-distance and Tukey M-estimator.Firstly,we propose a k-distancebased method to compute user suspicion degree(USD).The reliable neighbor model can be constructed through incorporating the user suspicion degree into user neighbor model.The influence of attack profiles on the recommendation results is reduced through adjusting similarities among users.Then,Tukey M-estimator is introduced to construct robust matrix factorization model,which can realize the robust estimation of user feature matrix and item feature matrix and reduce the influence of attack profiles on item feature matrix.Finally,a robust collaborative recommendation algorithm is devised by combining the reliable neighbor model and robust matrix factorization model.Experimental results show that the proposed algorithm outperforms the existing methods in terms of both recommendation accuracy and robustness.

RFD-Rao and RFD-Wald tests for distributed targets with range walking effect

Two novel adaptive distributed target detectors, the range frequency domain-Rao （RFD-Rao） and range frequency domain-Wald （RFD-Wald） tests are proposed in this work. The application methods for these tests consider a partially homogeneous disturbance environment and a target range walking effect in a coherent processing interval （CPI）. The asymptotic performance of the detectors is analyzed, and the constant false alarm rate （CFAR） properties with respect to the clutter covariance matrix and power level are shown. The performances of the proposed adaptive detectors are assessed through Monte-Carlo simulations, and the results are presented to demonstrate the effectiveness of the proposed detection algorithms compared to those of similar existing detectors.

Performance of an Improved One-Way Error Reconciliation Protocol Based on Key Redistribution

In data post-processing for quantum key distribution, it is essential to have a highly efficient error reconciliation protocol. Based on the key redistribution scheme, we analyze a one-way error reconciliation protocol by data simulation. The relationship between the error correction capability and the key generation efficiency of three kinds of Hamming code are demonstrated. The simulation results indicate that when the initial error rates are （0,1.5%], （1.5,4%], and （4,11%], using the Hamming （31,26）, （15,11）, and （7,4） codes to correct the error, respectively, the key generation rate will be maximized. Based on this, we propose a modified one-way error reconciliation protocol which employs a mixed Hamming code concatenation scheme. The error correction capability and key generation rate are verified through data simulation. Using the parameters of the posterior distribution based on the tested data, a simple method for estimating the bit error rate （BER） with a given confidence interval is estimated. The simulation results show that when the initial bit error rate is 10.00%, after 7 rounds of error correction, the error bits are eliminated completely, and the key generation rate is 10.36%; the BER expectation is 2.96×10^-10, and when the confidence is 95% the corresponding BER upper limit is 2.17×10^-9. By comparison, for the single （7,4） Hamming code error reconciliation scheme at a confidence of 95%,the key generation rate is only 6.09%, while the BER expectation is 5.92x 10＂9, with a BER upper limit of 4.34×10^-8. Hence, our improved protocol is much better than the original one.

A Decade of Scien tific and Tech no logical Inno vati on at Chin ese Academy of Medical Sciences&Peking Union Medical College:Retrospect and Prospect

Focusing on the reform initiatives of Chinese Academy of Medical Sciences(CAMS) & Peking Union Medical College(PUMC) in medical scientific and technological innovation from perspectives of deepening the reform and optimizing the ecosystem of science and technology innovation,this article summarizes the highlights of CAMS & PUMC’s efforts in safeguarding people’ s health and promoting the Healthy China 2030 strategy through scientific and technological innovation in the fields including basic research,disease prevention and treatment,and medical technology in the past ten years.These achievements embody the endeavors and responsibility of CAMS& PUMC in realizing self-reliance and self-improvement of Chinese medical science and technology and highlight its contributions to the development of medical science and technology of China.

Dynamic Radiographic Analysis of Sympathetic Cervical Spondylosis Instability

Objective To investigate the correlation between subaxial cervical spine instability and cervical spondylotic sympathetic symptoms as well as the difference of cervical spondylotic subaxial instability between male and female patients. Methods We analyzed retrospectively 318 surgical cases of cervical spondylosis treated at Department of Orthopedic Surgery of Peking Union Medical College Hospital between July 2003 and December 2007. All cases were divided into group A without sympathetic symptoms (n=284) and group B with sympathetic symptoms (n=34). Angular and horizontal translation values between two adjacent vertebral bodies from C2 to C7 were measured separately on hyperflexion and hyperextension lateral cervical spine radiographs. Fisher's exact test was used to evaluate the correlation between subaxial cervical instability and sympathetic symptoms. Intragroup correlation between patient gender and subaxial cervical instability was also evaluated. Results Subaxial instability incidences in groups A and B were 21.8% (62/284) and 55.9% (19/34), respectively. Statistical analysis indicated a definite correlation between subaxial cervical instability and sympathetic symptoms (P=0.000). Among patients without sympathetic symptoms, subaxial instability incidences were 21.4% (37/173) in males and 22.5% (25/111) in females, respectively (P=0.883). While among patients with sympathetic symptoms, subaxial instability incidences were 27.3% (3/11) in males and 69.6% (16/23) in females, respectively, indicating significant difference (P=0.030). Subaxial instability was most commonly seen at C4-C5 intervertebral space in sympathetic cervical spondylosis patients. Conclusions High correlation exists between subaxial cervical spine instability and cervical spondylotic sympathetic symptoms, especially in female patients. Hyperextension and hyperflexion radiographs of cervical spine are important to assess sympathetic cervical spondylotic subaxial instability.

ATTACKS AND IMPROVEMENTS ON THE RFID AUTHENTICATION PROTOCOLS BASED ON MATRIX

Most of the Radio Frequency IDentification (RFID) authentication protocols, proposed to preserve security and privacy, are analysed to show that they can not provide security against some passive or active attacks. In this paper, the security of two matrix-based protocols, proposed by Karthikeyan and Nesterenko (KN protocol) and Ramachandra et al. (RRS protocol) that conform to Electronic Product Code Class-1 Generation-2 (EPC Class-1 Gen-2) standard, are investigated. Using the linear relationship of multiplication of matrix and vector, we point out that both protocols can not provide scalability, and they are vulnerable to passive impersonation attack. In addition, both protocols are totally insecure if the adversary can compromise one tag to extract the secrets. A modified lightweight matrix-based authentication protocol is presented, which can resist mainly common attacks on an RFID authentication system including eavesdropping, relay attack, desynchronization attack, impersonation attack and tag tracking attack. The new protocol also has the desirable scalability property and can keep secure under compromising attack.

Association between body mass index and erosive esophagitis:A meta-analysis

AIM:To conduct a meta-analysis to estimate the determinants of the association between erosive esophagitis (EE)and body mass index(BMI). METHODS:We identified the studies using PubMed. Studies were selected for analysis based on certain inclusion and exclusion criteria.Data were extracted from each study on the basis of predefined items.Metaanalyses were performed to verify the risk factors,such as obesity and gender. RESULTS:Twenty-one studies were included in this systematic review.These studies demonstrated an association between increasing BMI and the presence of EE[95%confidence interval(CI):1.35-1.88,overweight,odds ratio(OR)=1.60,P value homogeneity =0.003,95%CI:1.65-2.55,obese,OR=2.05,P< 0.01].The heterogeneity disappeared by stratifying for gender.No publication bias was observed in this metaanalysis by the Egger method. CONCLUSION:This analysis demonstrates a positive association between BMI and the presence of EE,especially in males.The risk seems to progressively increase with increasing weight.

Spatiotemporal interpolation of precipitation across Xinjiang, China using space-time CoKriging

In various environmental studies, geoscience variables not only have the characteristics of time and space, but also are influenced by other variables. Multivariate spatiotemporal variables can improve the accuracy of spatiotemporal estimation. Taking the monthly mean ground observation data of the period 1960–2013 precipitation in the Xinjiang Uygur Autonomous Region, China, the spatiotemporal distribution from January to December in 2013 was respectively estimated by space-time Kriging and space-time CoKriging. Modeling spatiotemporal direct variograms and a cross variogram was a key step in space-time CoKriging. Taking the monthly mean air relative humidity of the same site at the same time as the covariates, the spatiotemporal direct variograms and the spatiotemporal cross variogram of the monthly mean precipitation for the period 1960–2013 were modeled. The experimental results show that the space-time CoKriging reduces the mean square error by 31.46% compared with the space-time ordinary Kriging. The correlation coefficient between the estimated values and the observed values of the space-time CoKriging is 5.07% higher than the one of the space-time ordinary Kriging. Therefore, a space-time CoKriging interpolation with air humidity as a covariate improves the interpolation accuracy.

The Emergence of Modern Physics Research in China:The Yenching Department of Physics and the Rockefeller Foundation

Based on archival materials discovered in America,Britain,and China,this paper carefully examines the history of the short-lived and completely overlooked Department of Physics in the Premedical School of Peking Union Medical College(PUMC),and uncovers this department’s extensive interconnections with its counterpart at Yenching University.This project also looks into the Master of Science(MS)program in the Department of Physics at Yenching University,which,founded in 1927,was the first graduate program in physics in China.It was this MS program that transformed the Yenching Department from a largely premedical training center serving the PUMC into a prominent cradle of Chinese physics research.This Yenching Department,despite its small faculty and brief existence,nurtured many eminent Chinese physicists,such as Chao-Ying Meng孟昭英,Wen-Yu Chang张文裕,Ming-Chen Wang王明贞,Chia-Liu Luke Yuan袁家骝,Cheng-Shu Wang(Chang)王承书,Ho-Fu Lu卢鹤绂,Ting-Sui Ke葛庭燧,Kun Huang黄昆,and Chia-Lin Hsieh谢家麟.It would have been impossible to achieve these outstanding accomplishments without the effective leadership and pioneering work of C.H.Corbett,P.A.Anderson,Y.M.Hsieh,and W.Band—the first four Department Chairs—in combination with relatively abundant private funding,mostly from America,and extensive educational connections with Western institutions.This paper not only introduces in detail these four department heads and their contributions,but also discloses the unique role played by the Rockefeller Foundation via the China Medical Board and the PUMC in the development of the Yenching Department of Physics.