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1.
曹则贤 《物理》2008,37(4):271-278
图像可以帮助表述难以言传之意,所以它一直是物理学以及其他众多学科之重要表现工具.英文物理学文献中常遇到的与图像有关的词汇包括chart,map(mapping),histogram,scratch, sketch,image,plot,inset, painting,drawing,illustration,depict, delineation,profile,graphics,figure, picture,diagram(schematic diagram), graph, photograph, micrograph, cartoon,portrait,以及最近也可以作为稿件部分的film,flash,video,等等.研究者要善于选择最有效的图形表现工具,并要明了这些不同方式间的细微差别.然而,对物理学渐进境界之理解却又要求研究者心中不能着相.此中微义,愿读者诸公参详.  相似文献   

2.
用硝酸、高氯酸和氢氟酸溶解样品,在0.025 mol·L-1 EDTA介质中,采用一种标准溶液,用ICP-AES光谱法测定样品溶液中Ni,Cu,V,Mn,W,Mo,Co,Cr的含量。研究了基体和共存元素对分析元素光谱的影响,选择合适的波长,测定了分析结果的精密度,方法的检出限和回收率,结果表明,分析方法有很低的检出限,样品分析结果的相对标准偏差小于1%,加入回收率在98.2%~101.6%,方法准确、可靠、简便、快速,满足生产要求。  相似文献   

3.
 意大利首都罗马共有三所国立大学、四所教会大学、二所私立大学。罗马大学(又称罗马第一大学)座落在罗马近郊。它由十个学院(法律,金融与贸易,统计学,文学哲学与考古学,师范,数学物理与自然科学,机械工程,建筑,医疗,药学)、二所附属学校(航空机械,图书档案)、一所国立高等数学研究所、八所附属博物馆(矿业,地质,地理,古典艺术,动物,医学史,古生物学,人类学)组成。  相似文献   

4.
We propose a theorem for the quantum operator that corresponds to the solution of the Helmholtz equation, i.e., V(x1, x2, x3)|x1, x2, x3 x1, x2, x3| d3 x = V(X1, X2, X3) = e-λ2/4: V(X1, X2, X3) :,where V(x1, x2, x3) is the solution to the Helmholtz equation ?2V + λ2V = 0, the symbol : : denotes normal ordering, and X1, X2, X3 are three-dimensional coordinate operators. This helps to derive the normally ordered expansion of Dirac’s radius operator functions. We also discuss the normally ordered expansion of Bessel operator functions.  相似文献   

5.
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.  相似文献   

6.
 当暴风雨即将来临的时候,满天阴霾,空气沉闷,正所谓"山雨欲来风满楼,黑云压城城欲摧"。突然,一声霹雳,一道强光划破长空,照得天空和大地无比灿烂。天上的云层,地上的山水,像水洗过一样,尽收眼底。这就是闪电,是云层与云层之间,云层与大地之间由火花放电产生的巨大的电火花。  相似文献   

7.
曹则贤 《物理》2011,40(5):338-341
碰撞过程(impact,bombardment,collision)难免崩出来一些物质,于是就有了sputter,splash,spatter,spurt等物理上也算常见的词汇,它们同spew,spit,sputum,sprout等同源.  相似文献   

8.
《广西物理》2014,(2):F0004-F0004
1.来稿要求科学性准确,逻辑性强,文字简练,数据可靠,图表清晰,具有创新性或一定新意。每篇文章字数(包括图、表)以不超过6000字为宜。来稿(按顺序)必须包括:题目,作者姓名,作者单位(包括所在地和邮政编码),中文摘要(不超过300字),关键词(3~8个),中图分类号,正文,参考文献。  相似文献   

9.
1 总体评价 2009年全国高考(非课改区)理科综合物理试卷共两套,其中:甲卷供云南,贵州,黑龙江,吉林,甘肃,新疆,内蒙古,青海,西藏等省、自治区使用;乙卷供湖北,湖南,河北,河南,山西,陕西,江西,广西等省、自治区使用.  相似文献   

10.
星辉南极,荣颐衍生,喜迎王志符先生百龄寿诞,曷胜欣慰.我蛰居沪渎,云山遥隔,未能趋春城造府叩贺,停云遐企,无任绻依.念往昔夙蒙惠爱,时挹清芳,篆结中怀,与时俱永.自念未酬高谊,为此,特修芜函,回忆20余年深受先生大教之历历往事,作一扫描式回顾,濡笔为文,遥申祝嘏之忱.我早年虽未受先生親炙,但在1959年秋因工作需要和本人酷爱数理学科,遂从同济大学新建立的水利工程系,  相似文献   

11.
String theory suggests that black hole microstates are quantum, horizon sized ‘fuzzballs’, rather than smooth geometries with horizon. Radiation from fuzzballs can carry information and does not lead to information loss. But if we let a shell of matter collapse then it creates a horizon, and it seems that subsequent radiation will lead to information loss. We argue that the resolution to this problem is that the shell can tunnel to the fuzzball configurations. The amplitude for tunneling is small because we are relating two macroscopically different configurations, but the number of states that we can tunnel to, given through the Bekenstein entropy, is very large. These small and large numbers can cancel each other, making it possible for the shell to tunnel into fuzzball states before a significant amount of radiation has been emitted. This offers a way to resolve the information paradox.  相似文献   

12.
有效反射面积小,运动速度快的空间低轨卫星和小碎片的日益增多对现有地基探测跟踪技术提出了挑战。本文分析了国外现有低轨小目标光电探测技术的发展现状,结合低轨小目标的探测需求,提出了一种用于低轨微小卫星及小碎片搜索/跟踪探测的机动式车载大视场光电望远镜设计方案。介绍了该望远镜的光学系统、跟踪架及载车,描述了它的工作模式和图像处理,讨论了系统的搜索和探测能力。结果表明,该望远镜对300 km轨道高度的目标搜索能力达到13.5星等(相当于直径5 cm目标),可以满足搜索和跟踪低轨微小卫星及小碎片探测的实际需求。  相似文献   

13.
《Physics letters. A》2020,384(14):126267
The propagation of an intense laser beam in an alternating corrugated plasma channel, which has a wide region and a narrow region in one corrugated space period, is investigated. Compared with the usual corrugated plasma channel, it is found that there are many more resonance peaks and many more abundant beat-like wave phenomena for the laser beam in this extended channel. Moreover, the much narrower region in some special alternating corrugated channels can play the role like a plasma lens for some laser beams, i.e., it can obviously change the laser spot size from small (large) to large (small) amplitude when the laser passes through the narrow region. These results are well confirmed by the final numerical simulations of wave equation and particle-in-cell approach.  相似文献   

14.
The plasma waves and coupled plasmon-acoustic waves due to piezoelectrical effect in superlattices are investigated theoretically. The dispersion relations are obtained, and it is shown that under certain conditions the group velocity of the waves can be extremely small.  相似文献   

15.
The diffusion of small palladium clusters on MgO(100) is theoretically investigated. It is found that small clusters can diffuse even faster than isolated adatoms by a variety of mechanisms (some of which are novel), such as dimer rotation, trimer walking, tetramer rolling, and sliding. The consequences of the diffusion of small clusters on the growth of Pd aggregates on MgO(100) are investigated, and it is shown that fast mobility of clusters larger than a single atom is essential to bring the theoretical results into agreement with the outcome of molecular beam epitaxy experiments.  相似文献   

16.
《Physica A》2006,365(2):556-564
A new characteristic (residual closeness) which can measure the network resistance is presented. It evaluates closeness after removal of vertices or links, hence two types are considered—vertices and links residual closeness. This characteristic is more sensitive than the well-known measures of vulnerability—it captures the result of actions even if they are small enough not to disconnect the graph. A definition for closeness is modified so it still can be used for unconnected graphs but the calculations are easier.  相似文献   

17.
In heavy nuclei where the thickness of the diffused edge is relatively small, a certain sharp effective surface can be defined which characterizes the shape of the nucleus, and it can be considered as a collective dynamic variable. It is shown that the problem of fluid dynamics can be simplified by reducing it to simple linearized equations for the dynamics in the nuclear interior and boundary conditions set at the effective dynamic sharp surface of the density distribution. These conditions are derived from the fluid dynamical equations. Transitional densities obtained from this simple model are compared with the numerical solution of fluid dynamical equations.  相似文献   

18.
The decay B(d)-->phi K(S) is a special probe of physics beyond the standard model (SM), since it has no SM tree level contribution. Motivated by recent data suggesting a deviation from the SM for its time-dependent CP asymmetry, we examine supersymmetric explanations. Chirality preserving contributions are generically small, unless gluino is relatively light. Higgs contributions are also too small to explain a large asymmetry. Chirality flipping LR and RL gluino contributions actually can provide sizable effects without conflict with all related results. We discuss how various insertions can be distinguished, and argue the needed sizes of mass insertions are reasonable.  相似文献   

19.
DNA gel not only uses the skeleton function of hydrogel but also the biological function of DNA to realize the unified fusion of the structure and function of hydrogel material. By introducing specific small molecules into the DNA gel, it can respond to pH, temperature, ultraviolet, infrared, metal ions, and drug small molecules. To further realize the detection and loading of various small molecules in the biomedical field, the specific recognition and detection of heavy metal ions and toxins in the environment are done. In this paper, the preparation of pure DNA gel and hybrid DNA gel, their detection in the biomedical and environmental fields are reviewed, and their prospects and further development directions are discussed.  相似文献   

20.
The dynamical zeta function is usually defined as an infinite (and divergent) product over all primitive periodic orbits. It is possible to show that as variant Planck's over 2pi -->0 it can be represented as det(1-T), where the operator T(q,q') defines the semiclassical Poincare map. Here, certain consequences of this representation for chaotic systems are discussed. In particular, it is shown that the zeta function can be expressed through a subset of specially selected orbits, the error of this approximation being small as variant Planck's over 2pi -->0. Assuming that the chosen Poincare surface of section is divided into small cells of phase-space area of 2pi variant Planck's over 2pi, these trajectories are uniquely characterized by the requirement that they never go twice through the same cell.  相似文献   

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