用电象法的物理思想和注意的问题

本文从静电场的唯一性定理出发，用移荷保场的思想给出电象法清晰的物理思想和物理图象．

槐花赋

山崖红梅撒香粉,河边翠柳抽新芽。布谷鸟告诉人间——春天来到了。田野里绿油油的禾苗显生机,山川间清潺潺的流水乐哈哈;万紫千红百卉含苞绽蕾争春,满园春色万花喷芳吐艳竟华。且不叙赤橙黄绿青兰紫之情,也不赞海棠月季红牡丹之花;问君最爱哪一枝?赋歌一曲杨槐花! 槐花呀槐花,为什么——盘古开天从未有人为你称颂赞美?自史至今从未有人为你写诗作画?因为你既不象红梅那样——在冰天雪地里盛开引人注目,又不象荷花那样——在公园池塘里怒放水灵娇娜;因为你既不象桂花那样——专会吐香惹人品味,又不象海棠那样——光凭艳丽的姿色争享春华。那么——为什么?为什么??为什么???你会使我酷爱!你能引我情发?

如何激活想象力

想象力的培养是小学语文教学中必须充分注意到的。 一是想象可以使学生形成学习的“兴奋点”,调动学习的主动性和积极性。例如,学生作文要写一座凌空高架江面的大桥,如果就事论事,未免平淡无奇。如果教师引导学生展开想象,大桥像是雨后天晴出现的一道彩虹,再进一步想象到通过彩虹可以直达天宫。

The Symbolism of the Skull in Vanitas： Homo Bulla Est

In Dutch vanitas imagery of Homo bulla est there is a sad child （homo） holding a scalloped shell filled with soap and water. Although the child is amused and playing with the formation of beautiful transparent water circles, his expression is mischievous and melancholic. Blooming flowers and dead trees, burning urns, and cloudy landscapes also accompany this gloomy imagery, which alludes to a warning about moral behavior. The first part of this essay deals with a brief history about the symbolism of the skull in vanitas imagery （1590-1630）. And the second part of the essay focuses on two prints by the Dutch artist and printmaker from Haarlem, Hendrick Goltzius （1558-1617）, who honored this proverb Homo bulla est in Allegory of Transience as a remembrance of the brevity of life.

Investigation of the binding behavior of human serum albumin and phosphorothioate oligodeoxynucleotide

Aim To study the binding behavior between human serum albumin （HSA） and phosphorothioate oligodeoxynucleotide （PS- ODN） and the effects of bivalent cations on the interaction. Methods Surface plasma resonance, circular dichroism and fluorescence experiments were conducted. Results （ 1 ） the binding ability was decreased along with the increase of pH; （2） Zn^2＋and Ni^2＋ enhanced the interaction between PS-ODN and HSA; （3） Upon PS-ODN binding, the conformation of HSA was changed with an increase of β - sheet. Conclusion The results provide experimental evidences to the hypothesis that PS-ODN binds with HSA in the positive potential region, and histidine residues located in the region play a crucial rule in the interaction.

Jan Haicksz Steen＇s Woman at Her Toilet： ＂Provocative Innuendos＂

Jan Haicksz Steen （1626-1679）, a Dutch actor, poet and painter, engaged the viewer with various innuendos and double entendres in his paintings about Woman at Her Toilet. Decoding the conceits introduces the viewer to Dutch artistic astuteness and popular culture. Steen drew the observer into his picture plane through a series of emblematic vignettes. Although he raised questions about cultural mores, morality, and religiosity, none are judgmental. On the contrary, it is the viewer who might or might not articulate a moral judgment according to personal experiences. For Steen, the imagery, filled with complex conceits, is an artistic visual representation to delight the eyes, tantalize the senses, and maybe even spark the intellect.

A control model for hysteresis based on microscopic polarization mechanisms in piezoelectric actuator

Aiming at the limitation of control accuracy caused by hysteresis and creep for a piezoelectric actuator, the hysteresis phenomenon is explained based on the microscopic polarization mechanism and domain wall theory. Then a control model based on polarization is established, which can reduce the hysteresis and creep remarkablely. The experimental results show that the polarization control method is with more linearity and less hysteresis compared with the voltage control method.

Estimation of the Volga-Caspian Water Ecosystems Stability under the Possible Climate Change and Anthropogenic Load

In this article, possible consequences of the Volga-Caspian water ecosystems change as a result of climatic changes are stated according to the data scenarios of Worldwide Meteorological Organization.

Electrokinetic phenomena of poly(vinyl butyral) hollow fiber membranes in different electrolyte solutions

The streaming potential of poly（vinyl butyral） （PVB） hollow fiber membrane was studied in different electrolyte solutions （including NaCl, KCl, CaCl2 and MgCl2）, the effects of ionic strength, ion valence and pH value on the streaming potential （SP） of the membrane were investigated. The zeta potentials and surface charge densities of the membrane were estimated on the basis of Helmholtz-Smoluchowski equation and Gouy-Chapmann theory. The results show that the PVB membrane has a weak negative charge due to the specific adsorption of ions. Moreover, the streaming potential, the zeta potential and the surface charge density of the membrane depend strongly on the salt concentration and the type and valence of ions. The iso-electric point （IEP） of the PVB membrane is arotmd 3.0 in the monovalent media （NaC1 and KC1） and 3.5 in divalent electrolytes （CaCl2 and MgCl2）. A few retentions were obtained for PVB membrane in low concentration solutions. This result verifies that the negative charged membrane surface can reject inorganic solutes by means of electrostatic repulsion effect even though the size of membrane pores is much larger than the size of salts.

Study of beat phenomenon on a pile-supported pipeline system subjected to wave loading

Classical beat phenomenon has been observed in most combined systems. The focus of this paper is to provide a better understanding of this phenomenon in an offshore pile-supported pipeline system. The beat phenomeon is caused by the coupling movement of the pipeline and its vertical pile support under certain conditions. It can induce excessive vibration and cause fatigue failure at pipe elbow. However, in some circumstances it does not exist. Numerical results in both frequency and time domains are presented to elucidate this phenomenon in a combined pipeline system. The conclusions of this paper could give constructive guidance to future design of simply supported pipeline systems.

Charmonium Spectrum and Their Transitions in Relativistic Quark Models

Using the phenomenological relativistic harmonic model （RHM） for quarks, we have obtained the masses of S wave charmonium states. The full Hamiltonian used in the investigation has Lorentz scalar plus vector confinement potential, along with the confined one gluon exchange potential （COGEP）. A good agreement with the experimental masses for the ground state and the radially excited states is obtained for both the triplet and singlet S wave mesons. The calculated charge radii, meson decay constants, leptonic decay width, two photon decay width, and the radiative M1 decay width are in good agreement with the experimental results.

Focal Plane Image Assembly of Subpixel

This paper describes the scanning assembly principle and construction of scanning assembly sample.The factors that affect assembly accuracy are analyzed.There are two steps in CCD focal plane scanning assembly.The first is rough assembly,and the second is accurate assembly.In this paper,the moiré fringe is introduced in judging assembly accuracy directly and accurately.The equation for optical transmission characteristics of CCD Moiré fringes is presented.The measurement of Moiré fringes can be completed when some conditions are satisfied.2D_assembly error can be obtained by using digital correlation filtering technique.Finally,the result of focal plane scanning assembly is presented.The result is in good accordance with theory.

Experimental Researches of a Hydrogen Fuelled SI Engine

The paper presents the results of the experimental research which was carried out on the spark ignition engine, experimental model, fuelled with hydrogen by direct injection method, using qualitative load adjustment method for engine running control. Also, the hydrogen injection solution at the beginning of the compression stroke, after the inlet valve closing, assures the cylinder cooling by inlet air avoiding in that way uncontrolled ignition phenomena and inlet back fire. Using this fueling method avoided the abnormally hydrogen combustion phenomena＇s for stoichiometric dosage operating conditions, achieving -30 % engine power increase. Hydrogen engine runs with very lean mixtures, due to engine load qualitative adjustment, a dosage value that leads to a reduction of the engine power with -25% from maximum power value. This provides a higher engine efficiency at low loads, the best results was obtained for λ=2- 4 air-fuel ratio values. The influence of the mixture quality on burning process, on polluting and energetically engine performances at the fuelling with hydrogen using direct injection method are presented. Because of the higher combustion temperature, the NOx emission level is higher for λ=1 - 2 comparative to gasoline fuelled engine, but decreases a lot for leaner mixture values, λ〉2.5.

Topological surface states and flat bands in the kagome superconductor CsV_(3)Sb_(5)

Exotic quantum phenomena may appear in material systems with multiple orders or phases,where the mutual interactions can give rise to new physics beyond that of each component.Here,we report spectroscopic evidence for a unique combination of topology and correlation effects in the kagome superconductor CsV_(3)Sb_(5).Topologically nontrivial surface states are observed near the Fermi energy(E_(F)),indicating that the topological physics may be active upon entering the superconducting state.Flat bands are observed,suggesting that electron correlation effects are also at play in this system.Our results reveal the peculiar electronic structure of CsV_(3)Sb_(5),which holds the potential for realizing Majorana zero modes and anomalous superconducting states in kagome lattices.They also establish CsV_(3)Sb_(5)as a unique platform for exploring the interactions between the charge order,topology,correlation effects and superconductivity.