邮票上的物理学史⑨--牛顿

"牛顿由于发现了万有引力定律而创立了科学的天文学,由于进行了光的分解而创立了科学的光学,由于建立了二项式定律和无穷理论而创立了科学的数学,由于认识了力的本性而创立了科学的力学."恩格斯的这段话很好地总结了牛顿的科学业绩.为了纪念牛顿在科学上的伟大建树,许多国家发行了多枚一套的邮票.     

物理实验开放式教学初探

网上预约实验实现了各校区资源共享、教学内容有弹性满足了不同层次学生的需求，开放式教学增强了教师的责任心，激发了学生学习的主动性和积极性，提高了实验教学质量，充分利用了实验室的资源，取得了较好的效果。     

自由落体实验的改进

针对教材中自由落体实验操作的不稳定性,改进了实验,增强了实验操作的稳定性,提高了实验的精确度,减少了实验次数,节省了时间,提高了课堂效率.     

大统一理论:回顾与展望

本文系统地讨论了大统一理论的来龙去脉。回顾了大统一理论的发展历史,讨论了其发展现状及存在问题,指出了进一步发展的方向。本文重点介绍了SU(5)和SO(10)两个模型,讨论了Higgs场、规范等级、渐近自由、重正化等问题。文章进而讨论了一些有趣问题,比如提供了对宇宙重子起源的解释、计算了质子衰变寿命、论述了B-L是否守恒以及讨论了中子和中微子可能有的振荡现象等。     

双波段扫描辐射计的研制

介绍了一种新型小视场、高精度的双波段扫描辐射计。描述了系统的特点,分析了系统的总体方案。介绍了系统的工作原理,对系统的NETD进行了估算,对其探测器的选择、光学系统设计、调制系统设计、扫描机构设计、信号处理等方案进行了详细论述,对系统的标定和测量原理进行了分析,并给出了相应的计算公式。给出了系统的检测结果。     

大统一理论:回顾与展望

本文系统地讨论了大统一理论的来龙去脉。回顾了大统一理论的发展历史,讨论了其发展现状及存在问题,指出了进一步发展的方向。本文重点介绍了SU(5)和SO(10)两个模型,讨论了Higgs场、规范等级、渐近自由、重正化等问题。文章进而讨论了一些有趣问题,比如提供了对宇宙重子起源的解释、计算了质子衰变寿命、论述了B-L是否守恒以及讨论了中子和中微子可能有的振荡现象等。     

La/酸化膨润土吸附剂的表征与除磷性能

以酸化改性膨润土为载体,采用浸泡法制备了稀土La掺杂的La/酸化膨润土吸附剂.通过XRD和FTIR对其结构进行了表征,探讨了膨润土的改性机理,研究了该吸附剂对废水的除磷性能.结果表明：酸化过程洗掉了膨润土中的杂质和氧化铝,稀土镧的掺杂在膨润土层间及表面引入了一定数量的羟基化合物,改善了膨润土的层间结构并生成了新的La-O-Si键,实现了La与膨润土的复合,提高了膨润土的吸附性能.     

地磁场测量实验教学设备的改造、替代及软件选取

介绍了周期幅值法测量地磁场的实验方法,指出了原实验设备存在的问题,同时提出了实验设备的改造方案,并详细介绍了如何软选取件模块.该工作降低了实验教学的维护成本,节约了因等待维护耗费的大量时间,保证了实验教学的顺利进行.     

控制环量设计涡轮的实验研究

采用控制环量方法设计了一单级涡轮。该方法打破了传统的设计规律,为验证该方法的可靠性进行了模型试验。在宽广的范围内测定了总特性;在设计点附近作了沿叶高效率分布及动叶进、出口速度三角形的测定。本文给出了主要试验结果并作了简要分析。结果表明基本上达到了设计要求,控制环量设计的主要特征得到了验证,该方法基本可行。     

纳米流体脉动热管的流动与传热性能研究

建立了纳米流体脉动热管的分析模型,将相变传热项合理引入了汽塞能量微分方程;液塞动量方程中考虑了剪切力的影响;纳米流体的物性采用了当量处理方法.采用数值迭代方法进行了求解,得到了汽塞压力、温度、质量的变化波形,分析了波形的频率,进而解释了初始条件、重力等对脉动热管的流动与传热影响的机理.     

INAA for determination of trace elements in bottom sediments of the Selenga river basin in Mongolia

Instrumental neutron activation analysis (INAA) was used for the determination of major, minor and trace elements in samples of bottom sediments of the inflows of the Selenga river basin to assess the impact of the contamination from the industrial complex Erdenet and other industrial enterprises in Mongolia. A total of 42 elements (Na, Mg, Cl, K, Ca, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Sr, Rb, Sr, Zr, Nb, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Tb, Dy, Tm, Hf, Ta, W, Au, Hg, Th, and U) was determined by combination of conventional and epithermal neutron activation analysis at the IBR-2 reactor, FLNP JINR, Dubna. For the first time such a large set of elements was used for characterization of the bottom sediments as accumulating media which may reflect industrial contamination of the water basin. The concentrations of heavy metals and other trace elements in the samples from three inflows of the Selenga river basin were compared with data from the previous studies. It was shown that the industrial zone of the Erdenet Mining Corporation (EMC) and gold mining zone Zaamar are the sources of strong environmental contamination. The concentrations of Cu and Sb determined in sediment samples of the River Khangal and Govil near the EMC exceed average crustal rock and soil values by factors of 50 and 15, respectively. In the area of the gold mining zone Zaamar concentrations of Au, As, and Sb exceed crustal rock and soil values by factors of 4, 25, and 6, respectively. The relatively high levels of As, V, Zn, V, and Sr in the sediments of the studied rivers are obviously due to the discharges of untreated wastewater of desalination plant, electrical power station, textile industry and mining activities as well as domestic wastewater.     

Holstein极化子能带和有效质量的温度依赖性

使用正则变换方法,考察了一维Holstein极化子能带和有效质量的温度依赖性。结果表明,对于一定的电子声子耦合强度,Holstein极化子能带宽度随温度升高而变窄,有效质量随温度升高而增大。特别是当电子声子耦合强度足够大时,极化子能带宽度在很小的温度范围内会迅速地变为零,我们认为这种情况实际上是极化子从能带状态向自陷局域态的迅速转变,这与通常的相变现象有点相类似。当电子声子耦合常数越大时,极化子有效质量随温度的升高而增加得越快。很显然,研究电子声子相互作用,对理解固体的光学和输运等性质将有重要的意义。     

指纹识别技术的发展

指纹识别技术由于具有独特的防伪性、可靠性、方便性、实时性、灵活性、可接受性、安全性和兼容性，因而可广泛应用于公安、保安、机要军事、商业等领域。本文首先对指纹识别技术的技术背景做了较为详细的介绍，包括个人识别和特征识别、指纹识别及其优点、指纹识别的发展历史、其它识别办法的限制、指纹自动识别系统的发展现状等，然后对指纹识别技术的市场前景做了综述，包括指纹锁和指纹卡的潜在应用。总之，随着市场的推动和技术的提高，指纹识别应用领域将会越来越广泛，在人们生活中的作用也会越来越重要。     

Magneto-electronic properties of the AA- and ABC-stacked graphites

In this study, we apply the tight-binding method to magneto-electronic properties of the AA- and ABC-stacked graphites, which are strongly dependent on the interlayer interactions, the magnetic field, and the stacking sequences. First of all, the interlayer interactions induce the significant changes in the energy dispersions, the band symmetry about the Fermi level, the overlap between valence and conduction bands, the band width, and the band-edge states or the symmetry points. Then, the magnetic field induces the Peierls phase in the Bloch functions and thus strongly affects the energy dispersions of the Landau Levels, the subband spacings, the energy width, and the special structures in density of states (DOS). Finally, the stacking sequences dominates over the low-energy band overlap and the anisotropy of energy bands. The effects mentioned above are exactly reflected in the density of state. Here, DOS exhibits the 3D, 2D, and 1D characteristics.     

Elemental Analysis of Tea Leaves (Camellia Sinensis) and Their Own Soils at Eastern Black Sea Region in Turkey

People consume tea brewed from the leaves of the Camellia sinensis plant for about 50 centuries. Health benefits of the tea have been investigated for about three decades. Especially green tea shows antitoxic and lots of properties with its determined ingredients. Turkey is not only the one of the best consumer and but also good producer of the tea as being 5 th producer all over the world. It grows eastern region of the Turkey and high quality tea is imported and exported. To have quality tea, grooving soils are also crucial. In the current research, Tea leaves and their own grown soils were collected from 20 stations where the most tea producer cities as Trabzon, Rize and Artvin tea fields of the eastern of Black Sea Region in Turkey. The cultivated tea and their own grown soil samples were analysed by using EDXRF Spectrometry. In the soil samples, the elements Mg, Al, Si, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Sr, Ba, Pb on percent level and the elements Mg, Al, Si, P, Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn and Sr in the tea leaves were detected by using SKRAY 3600-EDXRF.and also the obtained data were evaluated with the Kriging interpolation of geostatistical method. Element content were investigated in the soil and tea samples according to the geological situations and also the relation of elemental difference between the tea and the own grown soil. Pb/Zn ratio was also anaysed in the samples.     

Classical theory of the octonian field

We develop a nonassociative classical theory of the octonion spinor field. We construct the Lagrange function, the field equations, the solutions, the energymomentum tensor, the spin, and the associator, which is a new quantum characteristic. We consider the interaction of the octonion spinor field with the electromagnetic field. We show that, in the case of a massless field, the energy, the spin, and the associator can be measured simultaneously, while in the case of a field with rest mass, only either spin and energy or spin and associator can be measured simultaneously.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 58–62, December, 1986.     

基于紫外光谱法和有监督模式识别技术对氯化钠、氢氧化钠和β-苯乙胺种类的鉴别

β-苯乙胺(PEA)是一种重要的有机合成中间体,在PEA生产过程中,最终的生成物中常常为含有氯化钠(NaCl)、氢氧化钠(NaOH)和PEA三者的混合物。因此,对NaCl,NaOH,PEA和混合物种类进行鉴别,有利于PEA的合成以及定性检测,需建立紫外光谱快速鉴别NaCl,NaOH,PEA和混合物种类的方法。利用紫外光谱法分别测量了NaCl,NaOH,PEA和混合物在190～400 nm范围的吸收光谱。首先,采用偏最小二乘法(PLS)提取紫外光谱的主成分信息,用少数的主成分信息取代原始变量,减少模型的复杂度。用PLS提取NaCl,NaOH和PEA在前三个主成分空间中得分向量值的分布。可知NaCl,NaOH和PEA前三个主成分累计贡献率分别是96.64%,99.44%和99.95%。因此,NaCl、NaOH和PEA的前三个主成分基本包含了大部分的光谱信息。其次,用获得的三个主成分作为输入变量,采用线性判别分析（LDA）,Sigmoid SVM,RBF-SVM,RBF-ANN,BP-ANN和人工蜂群(ABC)优化神经网络(ABC-BP-ANN)等模式识别方法对NaCl,NaOH和PEA种类进行判别,获得总的敏感性分别为95.6%,95.6%,95.9%,95.8%,96.9%和99.6%。由于NaCl和NaOH特征吸收峰很相似,主成分得分向量会出现重叠现象,导致NaCl和NaOH的种类鉴别出现误判。通过对比六种分类方法,可知ABC-BP-ANN效果最优,BP-ANN次之,RBF-SVM和RBF-ANN结果相似,但比BP-ANN稍差,LDA和Sigmoid-SVM效果最差。最后,配制7种不同摩尔分数的混合物(混合物摩尔分数是指PEA物质的量占混合物总物质的量百分比),浓度范围为0%mol·L-1～60%mol·L-1,然后采用RBF-SVM,BP-ANN和ABC-BP-ANN三种方法对混合物种类进行判别。从敏感性和特异性结果可以得知,ABC-BP-ANN分类效果最好,BP-ANN次之,RBF-SVM分类效果最差, 由混合物得到的结果与单组分的结果相一致。结果表明,紫外光谱结合ABC-BP-ANN模式识别方法可以成功区分NaCl,NaOH,PEA和混合物的种类。该方法可作为一种简便、快速、可靠的方法用于NaCl,NaOH,PEA和混合物的种类判别,并为PEA的合成和质量控制提供理论依据和技术支撑。     

Bond dissociation energies in organometallic systems: substituent effects

A knowledge of the factors determining the magnitude of the bond dissociation enthalpy (BDE) is of importance to the advancement of theoretical organometallic chemistry and from the practical standpoint. The central atom and the substituents bound to it influence the BDE values; however, the interplay between the BDE and the substituent effects remains unknown. In this work, the literature data on substituent influence on the BDE of lithium, sodium, copper, silver, mercury, aluminium, gallium, silicon, germanium, tin, lead, phosphorus, antimonium, chromium, iron, cobalt, nickel, rhodium, and iridium compounds (37 series) have been analyzed, using the correlation analysis. Generally, the BDE values were first established to depend on the joint influence of the inductive, resonance, polarizability, and steric effects of substituents. The contribution of the polarizability effect ranges up to about 40%. Copyright © 2014 John Wiley & Sons, Ltd.     

拉曼光谱技术的汽油组分含量测定

为实现汽油中所含组分含量的快速测定,对93号、97号汽油,芳烃、烯烃、苯、甲醇、乙醇等几类物质,以及往汽油中添加几类物质后的410个汽油混合物进行拉曼光谱检测。将获取的原始拉曼光谱经过有效波段提取、平滑去噪、基线扣除、数据归一化等一系列预处理过程,最终提取出每个汽油混合样品光谱中所含的33个特征峰信息,依据现行的国标检测方法,以气相色谱法测定的汽油中各组分含量值为基础,结合化学计量学多重回归分析方法,建立了汽油组分含量测定模型。经过比较,使用多输出最小二乘支持向量回归机(MLS-SVR)建立的模型优于偏最小二乘(PLS)模型。MLS-SVR模型对汽油中芳烃、烯烃、苯、甲醇、乙醇测定精度均较好,预测均方根误差(RMSEP)分别为0.27%,0.30%,0.16%, 0.17%, 0.12%;相应的相关系数(r)为0.999 2,0.998 4,0.998 5,0.992 6,0.996 8。通过对未知混合汽油样品的测定,证明了该方法具有较好的推广预测精度,预测均方根误差不超过0.5%,能够满足工业中的测量需求。拉曼光谱结合多输出最小二乘支持向量机为汽油组分测定提供了一种高精确、快捷、方便的测定方法。     

无回热混合制冷剂循环(MRC)液化天然气流程的系统模拟

针对混合制冷循环液化天然气流程的热力学研究进行流程的系统模拟。系统介绍了第一个多股换热器前高低压制冷剂之间不进行回热的典型混合制冷循环液化天然气流程的计算方法;指出了进行此类流程计算时应注意的事项:针对特定的参数进行了全流程的模拟,得到了流程各节点压力、温度、焓、熵、汽液两相流量、总流量、汽液两相摩尔分率;同时得到了流程中压缩机耗功、丙烷预冷量、制冷剂流量、各换热器的换热量等表示流程性能的参数