Showing papers by "Shanghai University published in 1994"

Practical circular-polarization maintaining optical fiber

Abstract: The present invention is directed to a circular-polarization maintaining fiber structure, containing a stress-applying filament whirling around a central core. The fiber is fabricable by any of the existing fiber-making methods. The fiber is capable of maintaining circular polarizations of light, segments of such fiber can be easily spliced by lining up the cores only, and the fiber tolerates well bending and random perturbations likely to occur in practice. The invention is immediately applicable to fiber gyroscope and other interferometric architectures, to a variety of sensors, and to coherent optical transmission.

Analysis of crack tip hydrogen distribution under i/ii mixed mode loads

Abstract: — The distribution of hydrogen in the vicinity of a crack tip was studied using SIMS (Secondary Ion Mass Spectrometry) under different ratios of I/II mixed mode loads. Modified WOL specimens with kinked slits were employed in the course of the experimental work. Spectrographic measurements show that under I/II mixed mode loading, both in the HIC and in the rmaxp directions, there are two hydrogen accumulation peaks ahead of the crack tip, corresponding to the location of the maximum hydrostatic stress and maximum equivalent plastic strain, respectively. Based on results obtained over a range of loading conditions from mode I to a high KII/ KI, ratio, it is shown that the mode II component has a clear influence on both peaks. The conditions for hydrogen redistribution are discussed in terms of crack tip stress-strain fields.

Investigation on SnS film by RF sputtering for photovoltaic application

Abstract: Tin sulfide (SnS) solar cell semiconductor thin films were prepared by an RF sputtering method. The component, crystal structure, optical properties and electrical properties of SnS films were measured. The relationship between the SnS films properties and the sputtering condition was discussed. Using Sb as a dopant and combining thermal annealing at elevated temperatures (about 400/spl deg/C), n-type SnS homojunction solar cell thin films were obtained.

New Chinese Cinemas: Spatiality and Subjectivity in Xie Jin's Film Melodrama of the New Period

Abstract: By analyzing the textual embodiment of a set of symbolic divisions valorized by the Chinese patriarchal socio-cultural order in classical Chinese fiction,drama,critical discourses and film melodrama and the ways in which these divisions contribute to the construction of a viewing subject implicated in the complex social relations that make up the Chinese social formation in spatial terms,we can gain new insights into the intertextuality of Xie Jin's film melodrama in terms of its relation to the traditional Chinese melodramatic paradigm and the political paradigm of the Mao period and the vital role it plays in the new period as a period of political and cultural transition.Focusing on Xie Jin' s deployment of a bipolar narrative pattern informed by the Chinese yin-yang cosmology that allows him to blend history with fiction and the socio-cultural and political function of his melodramatic treatment of touchy political issues and identity problems with recourse to specific mise-en-scene techniques and cinematic codes,the author argues that the significance of Xie Jin' s film melodrama which centers on the definition and redefinition of the social and political status of the main characters within a highly limited ethical and political discursive field lies in its function to provide women and other socially disadvantaged social groups with a semantically complex reference framework and new modes of moral expressivity to negotiate with the dominant forces in society and its capacity to mediate social contradictions and facilitate the construction of a collective subjectivity that promotes and affirms socio-cultural transformation in the new period.

[Influence of acupuncture at zusanli point on function of 5-HT and M receptor in rat's brain and spleen].

Abstract: 5-HT and muscarine (M) receptors total binding capacities (Rt) in different brain areas and spleen were determined using receptor radioligand binding assay (RLBA) after needling zusanli of rats. And the rats without needling and needling Taichong point were used as control. These results showed that 5-HT and M receptors Rt were decreased obviously than control group in rat's cerebral cortex, hippocampus, striatum, spinal cord and spleen when needling zusanli can produce obvious acupuncture analgesia. 5-HT Rt in brain stem and medulla oblongata was obviously decreased and not changed in thalamus. M receptor Rt value was not changed clearly in brain stem and medulla oblongata as well, but it was obviously decreased in thalamus. These results showed that effects of acupoints on Various meridians are different, thus the results of acupuncture at Zusanli are distinct from taichong.

Absorption mechanism of paeoniflorin across Caco-2 monolayer model

Abstract: Objective To research the absorption mechanism of paeoniflorin across Caco-2 monolayer model. Methods Depending on the Caco-2 cell monolayers drug transport model to study the double transport mechanism of paeoniflorin. To explore the effect of paeoniflorin absorption by time and drug concentration, the drug concentration was determined through the use of HPLC instrument and the Papp was calcalatad. Results In the Caco-2 monolayer model, the transport of paeoniflorin form Apical (AP) to Basolateral (BL) is similar to the transport form BL to AP. Conclusion The main mechanism of the paeoniflorin intestinal absorption in the Caco-2 monolayer model is passive transference.

Clinical and experimental study on Ligusticum wallichii mixture in preventing and treating bronchial asthma

Abstract: UNLABELLED To investigate the significance of Ligusticum wallichii Mixture (LWM) and its possible therapeutical mechanism in bronchial asthma, clinical and experimental studies were carried out. RESULTS LWM inhibited bronchospasm induced by histamine and acetylcholine in guinea pigs; the plasma level of TXB2 was decreased remarkably and the incubation period from antigen inhalation to asthma attack could be delayed by LWM; the incidence of asthma and its mortality were reduced in guinea pigs, compared with control, P < 0.01. In addition, the prolonged period of induced asthma attack was negatively correlated to the plasma level of TXB2 in guinea pigs (P < 0.01). It was observed that the plasma level of TXB2 was decreased, the forced expiratory volume in 1 sec (FEV1%) was elevated significantly in asthmatic patients after they were treated by LWM. Moreover, the total effective rate was significantly better than that in the control (92% : 62%). It indicated that: (1) The effects of airway allergic inflammation (AAI) might be the important pathological basis for the bronchial asthma, (2) TXA2 might be an important inflammatory mediator in asthma which could be taken as an useful biochemical parameter for evaluating clinical effects, (3) LWM could relax tracheal smooth muscle, improve pulmonary function, inhibit the synthesis and release of TXA2 with no side effects.

A stability study of Navier-Stokes equations (III)

Abstract: In this paper, the necessary conditions of the existence of C2 solutions in some initial problems of Navier-Stokes equations are given, and examples of instability of initial value (at t=0) problems are also given. The initial value problem of Navier-Stokes equation is one of the most fundamental problem for this equation various authors studies this problem and contributed a number of results. J. Lerav, a French professor, proved the existence of Navier-Stokes equation under certain defined initial and boundary value conditions. In this paper, with certain rigorously defined key concepts, based upon the basic theory of J. Hadamard partial differential equations1, gives a fundamental theory of instability of Navier-Stokes equations. Finally, many examples are given, proofs referring to Ref. [4].

Stability of navier-stokes equation(ii)

Abstract: In this paper, we make some comparisons between the solutions for Navier-Stokes equation and those for heat conduction equation.

Two-dimensional deformation of an anisotropic elastic body with a parabolic boundary

Abstract: In the present paper, two-dimensional deformation problems of an anisotropic body with a parabolic boundary are systematically analysed by using Lekhnitskii’s formalism and the mapping functions method, then a special structure—the half-infinite crack problem is studied through the obtained results, the singular fields and the stress intensity factors near the crack tip are also obtained.

Prescription design of Ophiopogon japonicus saponin enteric microsphere by spray drying technique

Abstract: Objective To explore the prescription factor on Ophiopogon japonicus saponin enteric microsphere by spray drying technique. Methods Observing the type and content of enteric coating material, the type of plasticizer, the type and dosage of antistickiness material by single factor. Optimizing the prescription by orthogonal test design. Results Both Eudragit Ⅱ and micronization silica gel made in China could meet the need of the preparation. The best prescription included the proportion between drug and enteric coating material (1∶4), the dosage of castor oil (1%), and the dosage of micronization silica gel (1.5%). Conclusion O. japonicus saponin enteric microsphere accorded with the expecting demand. The kind of medical subsidiary material made in China will be the main raw material in producing the enteric microsphere. The study of prescription design will provide the basis for realizing microencap-sulation in Chinese materia medica.

Mechanically Driven Amorphization in the Ta-Cu System.

Abstract: Amorphizing transformation by ball milling was studied in a system without miscibility of the elements, Ta-Cu, with nominal compositions of Ta 50 Cu 50 to Ta 90 Cu 10 . X-ray diffractometry, scanning and transmission electron microscopy were employed to monitor the structural evolution of the samples. The results show that a single phase of amorphous product was obtained for all the given samples after 100 h of milling. Differential thermal analysis shows that both the temperature and the activation energy for crystallization increase with the Ta content, implying that the Ta-rich alloys exhibit a better thermal stability

Stress analysis of thick ring shell submitted to the action of internal pressure

Abstract: In this paper, from asymptotic equations of thick ring shell obtained on the basis of the equations of three dimensional elastic mechanics using geometric small parameter α=r0/R0, we find the solutions of the stresses and the deformations of thick ring shell submitted to the action of internal pressure q.

Spatial－temporal discrete coordination of fem and direct integral method for transient dynamic problems

Abstract: In this paper, the coordination of spatial-temporal discrete of FEM and direct integral method is investigated. By analyzing the numerical error induced by spatial-temporal discrete, the principle of balancing the energy error induced by spatial discrete and the energy error induced by temporal discrete is presented, and the priori process and adaptive method for the coordination of spatial discrete and temporal discrete is obtained.

The application of multi-scale perturbation method to the stability analysis of plane couette flow

Abstract: This paper applies the multi-scale perturbation method suggested by Ref. [3] to investigate the linear stability behavior of distorted plane Couette flow. Using this method, the unstable Tollmien-Schlichting wave in plane Couette flow can be found. but not the most unstable mode. By comparing the results of this paper with those of Ref. [3], the effectiveness of this method is investigated.

The Thermal Stability of a TiAl Based Alloy

Abstract: The thermal stability of a TiAl based alloy was investigated through a series of high temperature exposures in air and vacuum. The microstructures were found to be thermally stable. The bending tests showed that both ductility and strength of air-exposed specimens decreased, but no significant variation was observed in those exposed in vacuum. The influence of alloy microstructure, thermal exposure temperature and time was also taken into account here.

A mixed method for the creep of a skin layer

Abstract: The creep of a skin layer under a distributed surface pressure was solved by an analytical method using Hankel transform and Laplace transform. The surface stress boundary conditions lead to a Volterra integral equation of the first kind, which was then solved by a numerical method. The IMSL subroutines DINLAP and DGQRUL were employed to numerically obtain the Hankel-Laplace inversion. The calculated displacements at two distinctive moments were compared respectively with those obtained by an elastic solution for either incompressible or compressible solid. The transient creep responses of the skin layer were also presented.

A distributed control testing system of rechargeable batteries

Abstract: A new type of distributed control testing system of rechargeable batteries (DCTSB) is introduced DCTSB consists of a field control unit, a process control unit, a management and control unit, and a three-level computer system According to the parameter preset, the DCTSB system can test the batteries automatically, record the dynamic process, classify all the batteries and manage all the data It has the function of self-check, configuration and fault-tolerance Apart from loading and disloading batteries on the testing bed, all other operations are performed by DCTSB automatically It has also a friendly man-machine interface >

The asymptotic solving equations of thick ring shelland its solution under moment m0

Abstract: In this paper, from the fundamental equations of three dimensional elastic mechanics, we have found a sequence of asymptotic solving equations of thick ring shell (or body) applied arbitrary loads by the perturbation method based upon a geometric small parameter a=ro/Ro, which may be divided into two independent equation groups which are similar to the equation groups for plane strain and torsional problems. Using these equations, we have also found first order and second order approximate solutions of thick ring shell applied moment Mo.

IMPROVE THE HOMOGENEITY OF ZnO VARISTOR — A WAY TO ECOMATERIALS

Abstract: Matrix of small electrods are made on the cross-section of ZnO varitor component. Measuremant shows the nonhomogeneity in electrial paramenters. From the observation and computer simulation the diversity of current passes through different places of the component is revealed. Analysis points out that in order to meet the requirement of ecological balance, improvement of the homogeneity of this kind of material is necessary.