Showing papers by "Sun Yat-sen University published in 1986"

Combination device for a computerized and enhanced type of external counterpulsation and extra-thoracic cardiac massage apparatus

Abstract: A combination device are provided for a microcomputerized and enhanced type of external counterpulsation and extrathoracic cardiac massage apparatus. In addition to balloons for the 4 limbs, the device also comprises a pair of lower-abdomen-buttock balloons and a chest balloon. It is controlled by microcomputer process. The various sets of balloons are sequentially inflated from the distal portion to the proximal portion during the diastolic period of the heart beat. The pressure is applied from the distal to the proximal portion gradually onto the 4 limbs, lower abdomen buttock and lower portion of the sternum. At the beginning of the cardiac systole all of the balloons deflate simultaneously. The cycle is then repeated. This device used for the treatment of diseases of the heart, the brain, the kidneys, the isohemic disease of the retina and the peripheral vascular disease with apparent curative effect. For those cases of sudden cardiac arrest, the computer gives orders according to need, so that the above-mentioned sets of balloons exert pressure sequentially from the distal portion to the proximal portion to force the blood to the adbomen, the chest and the head. Thereafter the device deflates suddenly, and then again the balloons sequentially inflate from the proximal portion to the distal portion to force blood back to the lower portion of the body. Thus the circulation goes on wavelike in succession to support adequate output as well as adequate cardiac blood inflow, and improves the effect of resuscitation.

Dynamic mechanical behaviour and phase separation of mixtures of polysulfone with bis[4‐(4‐ethynylphenoxy)phenyl]‐sulfone or poly(phenylene sulfide)

Abstract: The dynamic mechanical behaviour and microphase-separation structure of polysulfone blends with bis[4-(4-ethynylphenoxy)phenyl]sulfone and with poly(phenylene sulfide) were investigated using torsional braid analysis and scanning electron microscopy. The experimental results showed that the size and shape of dynamic mechanical damping peaks and the structure characteristics of polysulfone blends with sulfur-containing polymers do not only depend on the chemical and physical nature and the weight fractions of the two components but also on conditions of thermal treatment leading to cross-linking reactions. In these multi-component polymer systems, the initially compatible mixture turns into an incompatible two-phase system during heating.

Genetic polymorphisms of complement C6 and C7 in two Chinese populations

Abstract: Genetic polymorphisms of the complement components C6 and C7 in two Chinese populations (Beijing and Guangzhou) were investigated, using isoelectric focusing and immunoblotting technique. Three common and four rare allotypes of C6 were observed, and one of the rare allotypes was considered to be a new variant. Ten different patterns of C7 observed were classified into three homozygous and seven heterozygous phenotypes, indicating occurrence of four common and a new variant alleles. The new variants of C6 and C7 detected were designated as C6 B21 and C7 6, respectively. There was no statistically significant difference for C6 and C7 allele frequencies between the Beijing and the Guangzhou populations except forC7*4. TheC7*4 frequency was shown to be significantly higher in Beijing than in Guangzhou. No significant positive association between C6 and C7 alleles was found.

Measures for improving therapeutic results of esophageal carcinoma in stage III: preoperative radiotherapy.

Abstract: Surgical therapeutic results of esophageal carcinoma stage III in 245 cases admitted to our hospital from 1966 to 1982 are reported in this paper. In this series, 171 cases were treated by surgery alone and 74 cases treated with a combination of preoperative radiotherapy and surgery. Of the entire group, 184 cases underwent gastroesophagostomy or colon interposition for esophageal reconstruction preceded by resection of the cancerous esophageal segment. The resectability rate was 75.1%, and the resection operative mortality rate was 7.1%. The 5- and 10-year survival rates were 30.0 and 25.8%, respectively. In the group of 171 cases treated by surgery alone, the resectability rate was 73.1% (125/171), and the resectability in the middle third esophageal carcinoma was only 64.7% (44/68), while in the group of 74 cases treated by combination treatment, the resectability increased to 79.7% (59/74) and the resectability in the middle third esophageal carcinoma increased to 79.3% (46/58). The 5-year survival rate in the combination-therapy group (60.1%) was 42.9% higher than that of the group treated by surgery alone (17.2%) (p less than 0.01). However, the differences in the rates of resection operative mortality and operative complications between these two groups were not significant. Therefore, we think that preoperative radiotherapy for esophageal carcinoma in stage III is an effective measure for improving resectability and survival rate.

The dynamic mechanical behaviour of blends of polyphenylene sulfide with acetylene terminated sulfone

Abstract: The dynamic mechanical behaviour of blends of poly(phenylene sulfide) (PPS) with the acetylene terminated sulfone bis(4-(4-ethynylphenoxy)phenyl)sulfone (ESF) was investigated by torsional braid analysis (TBA). A uniform dispersed system of ESF/PPS may be obtained by a solution process at 200°C, and can be maintained during the heat treatment up to 400°C. The increase of Tg of the blended system was found to be inappreciable by one-step and short time (e.g. 1 h) heat treatment, whatever the ESF fraction is. By a long term heat treatment or by step-curing, the Tg of the system may be raised from 180 to 220°C, in company with the increase of rigidity at 300°C, compared with pure PPS. The flexural modulus and interlaminar shear strength of continuous unidirectional carbon fibre composites with a blended matrix of ESF/PPS = 10/90 are significantly higher than those of composites with pure PPS matrix. An einem mit Blends von Polyphenylensulfid (PPS) und einem acetylenterminierten Sulfon Bis(4-(4-ethinylphenoxy)phenyl)sulfon (ESF) impragnierten Kohlenstoff-Faser-Band wurde eine Torsionsanalyse zur Bestimmung des dynamisch-mechanischen Verhaltens durchgefuhrt. Ein gleichmasig disperses System kann durch einen Losungsprozes bei 200°C erzielt und wahrend der Hitzebehandlung bis zu 400°C aufrecht erhalten werden. Ein Anstieg von Tg bei den legierten Systemen war bei einer Einstufen-Kurzzeit-Erhitzung (1 h) kaum feststellbar, unabhangig von der Art der ESF-Komponente. Durch langes Erhitzen oder durch stufenweise Hitzebehandlung kann Tg von 180 bis 220°C anwachsen, parallel zu einem Anstieg der Steifigkeit bis 300°C gegenuber reinem PPS. Der Biegemodul und die interlaminare Scherfestigkeit eines kontinuierlich einachsig gerichteten Kohlenstoff-Faser-Verbundstoffs mit einer Matrix aus 10/90 ESF/PPS-Legierung sind signifikant hoher als bei einer reinen PPS Matrix.

Mössbauer spectroscopy in china

Abstract: Mossbauer spectroscopy is a dynamic field with applications ranging from physics to biology. This paper gives a review of Mossbauer spectroscopy activities carried out by different groups in China. About thirty groups are distributed all over China for both fundamental and practical aspects. In-beam Mossbauer setup was established at HIRAC accelerator in Lanzhou, and the nuclear scattering facility has already been planned at Shanghai Synchrotron Radiation Light Source. In this review, some recent developments and achievements are discussed, as examples: (1) Brownian motion in anisotropic media, (2) applications to archaeology, and (3) molecule-based magnetic materials.

An optimal control problem involving a class of linear time-lag systems

Abstract: A class of convex optimal control problems involving linear hereditary systems with linear control constraints and nonlinear terminal constraints is considered. A result on the existence of an optimal control is proved and a necessary condition for optimality is given. An iterative algorithm is presented for solving the optimal control problem under consideration. The convergence property of the algorithm is also investigated. To test the algorithm, an example is solved.

String theory in four dimensions with three families of chiral fermions and standard gauge symmetry

Abstract: A heterotic string theory in four dimensions is constructed by compactifying the ${\mathrm{E}}_{8}$\ifmmode\times\else\texttimes\fi{}${\mathrm{E}}_{8}^{\mathcal{'}}$ heterotic strings from 26 to 4 dimensions via a manifold ${T}^{22}$/G. The theory is modular invariant. In the low-energy limit, there are three families of chiral fermions with exactly the same quantum numbers as in the standard SU(3${)}_{C}$\ifmmode\times\else\texttimes\fi{}SU(2${)}_{L}$\ifmmode\times\else\texttimes\fi{}U(1) model. They couple to gravity and gauge fields with the gauge symmetry SU(3${)}_{F}$\ifmmode\times\else\texttimes\fi{}SU(3${)}_{C}$\ifmmode\times\else\texttimes\fi{}SU(2${)}_{L}$\ifmmode\times\else\texttimes\fi{}U(1 ${)}^{3}$. The ${\mathrm{E}}_{8}^{\mathcal{'}}$ is broken down to SU(3)' \ifmmode\times\else\texttimes\fi{}SU(4)'\ifmmode\times\else\texttimes\fi{}U(1)${\mathcal{'}}^{3}$. The SU(4)' group can play the role of the technicolor group to break the SU(2${)}_{L}$ \ifmmode\times\else\texttimes\fi{}U(1${)}^{3}$ symmetry.

A recent coincidence experiment of gravitational waves with long baseline

Abstract: The results of coincidence experiment which was carried out in the whole month of April, 1985 by two gravitational wave detectors in stanford and in Guangzhou are presented. It is found that up to sensitivity of h 10-16 the number of coincident events did not excess the number expected statistically.

Shortening of travelling-wave-amplified spontaneous emission by a transversal pumping scheme

Abstract: An experimental investigation on shortening of travelling-wave ASE employing a transversal pumping is presented A N2 laser with λ=3371 nm, pulsewidth: 700 ps is used as a pump source An ASE pulse with duration of 45, 55 and 45 ps from dye solution of Rh 6G, Rh B and C311, respectively, is obtained Pulse shapes of output signals generated from these solutions in three different pumping schemes are compared

The proof of Goka's conjecture

Abstract: If the system X_{k+1} = (A + u_{k}B)X_{k}, k = 0, 1, ..., is controllable with |u_{k}| for all \delta > 0 , then the eigenvalues of A lie on the unit circle. This is Goka's conjecture. Through algebraic transformation and discussion of invariant proper subsets, this note gives a proof of the conjecture, and shows that for more general discrete-time bilinear systems, the conjecture is still true.

Crystal structure of a 1:1 molecular adduct of hexamethylenetetramine with phenylacetic acid

Abstract: A 1∶1 crystalline adduct of hexamethylenetetramine with phenylacetic acid, (CH2)6N4·C6H5CH2COOH, has been isolated and characterized by X-ray analysis. The compound crystallizes in space groupI¯4 (No. 82), witha=20.576(3),c=6.907(1) A, andZ=8. The crystal structure is composed of a packing of discrete molecular aggregates corresponding to the stoichiometric formula, each being consolidated by a N⋯H-O hydrogen bond of length 2.643(8) A, which has no significant effect on the regular geometry of the (CH2)6N4 cage system. The C-CO2 and phenyl groups in the C6H5CH2COOH moiety make a dihedral angle of 74(1)°. The structure has been refined toR=0.071 for 1350 observed (∥F o ∥>2σ∥F o ∥) MoKα data.

Study on the fir bandpass filters consisting of two resonant grids

Abstract: A series of interference filters composed of two resonant grids, with resonant wavelengths λm <200μm, were constructed, and the dependence of the spectral characteristics on the separation of the two grids was studied experimentally in detail. The multiple-beam interference theory was applied to analyse the experimental results. The theoretical calculations and the experimental results are in good agreement. A method is presented, by which double-grid interference filters can be designed with the computer aid.

Effect of conjugation beyond multiple bonds: Part III. The nature of carbon—carbon bond length

Abstract: The effect of the change in the form of a carbon atom (tetrahedral, trigonal or linear) on the carbon—carbon bond length is studied by a statistical method. The interference of conjugative effects on bond length is eliminated by regression with the π-resonance integral contribution to energy. The charge or inductive effect is found to be insignificant in the regression. The shortening of the CC bond length in the change from a tetrahedral to a trigonal carbon atom is found to be 0.007 A, while the change from a trigonal form to a linear form shortens the CC bond by 0.0395 A. It is thus concluded that the change in form of the carbon atoms is not a major factor in shortening the middle CC bond of butadiene, as compared with that of ethane.

Ethylene Polymerization with Modified Supported Catalysts

Abstract: Slurry polymerization of ethylene giving high yields of polyethylene under ambient or enchanced pressure with catalyst of TiCl4/ MgCl2/AlEt3 (named “GZ-Catalyst”) prepared by comilling method has been studied. With modified catalyst comprising TiCl4, Ti(O-n-Bu)4/MgCl2/AlEt3 (named “ZS-Catalyst”), the yield of ethylene polymerization or ethylene/propylene copolymerization are raised up quite distinctly. For preparation of ultra high molecular weight polyethylene (UHMWPE), a modified catalyst of TiCl4/MgCl2/AlEt3, RMgCl (named “HE-Catalyst”) was found to be especially highly active. With catalyst comprising TiCl4, Ti (O-n-Bu)4/MgCl2, ZnCl2/AlEt3 (named “YJ-Catalyst”) or with catalyst comprising TiCl4,/MgCl2/AlEt3,ZnEt2, (named “ZE-Catalyst”), ethylene polymerization in absence of hydrogen gives' lower molecular weight polymer. A noval modified catalyst of TiCl4, NdCl3/MgCl2/ AlEt3, (named “SN-Catalyst”) is highly active for polymerization of ethylene as well as stereo specific polymerization of styrene and copolymerization of these two monomers. The effects of polymerization conditions and kinetics of ethylene polymerization with each of the above catalysts have been studied.

Studies on Chinese soft coral: 12. The structure of methyl sartortuoate, a unique new tetraterpenoid

Abstract: An unique new tetraterpenoid, with a rare skeleton different from the usual tetraterpenoids, has been isolated from the Chinese soft coral Sarcophyton tortuosum Tixier-Duriault and designated as methyl sartortuoate 1 It showed a formula C_(41)H_(62)O_8(M~+, m/z 6824469), [α]_D~(28)+1958(c, 00475, EtOH), m p 246～2465℃, and its structure has been deduced from IR, UV, MS, ~(13)C and 1~H NMR spectra, elaborated by double resonance experiments The single crystal X-ray diffraction experiment supported the structure 1 for methyl sartortuoate Acknowledgements We are deeply grateful to Mr Glen Bigam, University of Alberta, Canada, for 400MHz NMR measurements, especially for his outstanding decoupling techniques We also thank Li Chu-Pu, South China Sea Institute of Oceanology, Academic Sinica, for identification of the soft coral

The General Circulation and Heat Sources over the Tibetan Plateau and Surrounding Areas During the Onset of the 1979 Summer Monsoon

Abstract: The importance of the Tibetan Plateau (the Qinghai-Xizang Plateau) as an elevated heat source for the establishment and maintenance of the Asian summer monsoon circulation has been discussed by many authors (e.g., Flohn, 1957, 1968; Staff Members of Academia Sinica, 1958; Murakami, 1958; Yeh and Gao et al., 1979; Yeh, 1981, 1982) [see Luo and Yanai (1984) for a detailed review].

Electrostrictive effect in non-lead materials: BLTZ ceramics

Abstract: The temperature dependence of the dielectric constants and the electrostrictive coefficients of the lead-free ceramic system BLTZ were measured The results showed that the compositions had diffuse phase transition characteristics and relatively large electrostrictive effects in the vicinity of the Curie temperature

An improved defect model for schottky barrier formation on iii-v compounds

Abstract: An improved defect model has been proposed by combination of the defect model with the Bardeen model. The predictions based on this model can qualitatively explain the experimental results of the Schottky barrier formation on GaAs(110).