Showing papers by "Chinese Academy of Sciences published in 1982"
TL;DR: The minimized energies of parallelβ-sheets are considerably higher than those of the corresponding antiparallel β-sheets, indicating that parallel β-sheet are intrinsically less stable.
143 citations
TL;DR: In this paper, the general properties of quadratic systems are discussed and a discussion of the properties of Quadratic Systems is presented. The American Mathematical Monthly: Vol 89, No. 3, pp. 167-178.
Abstract: (1982). On General Properties of Quadratic Systems. The American Mathematical Monthly: Vol. 89, No. 3, pp. 167-178.
65 citations
TL;DR: In this article, the authors present the initial results of work on a new class of semiconductor metallization which appear to hold great promise as primary metallizations and diffusion barriers for high-temperature device applications.
Abstract: In this paper we present the initial results of work on a new class of semiconductor metallizations which appear to hold great promise as primary metallizations and diffusion barriers for high-temperature device applications. These metallizations consist of sputter-deposited films of high-T g amorphous-metal alloys which (primarily because of the absence of grain boundaries) exhibit exceptionally good corrosion resistance and low diffusion coefficients. Amorphous films of the alloys Ni-Nb, Ni-Mo, W-Si, and Mo-Si have been deposited on Si, GaAs, GaP, and various insulating substrated. The films adhere extremely well to the substrates and remain amorphous during thermal cycling to at least 500°C. Rutherford Backscattering (RBS) and Auger Electron Spectroscopy (AES) measurements indicate atomic diffusivities in the 10 -19 cm 2 /S range at 450°C.
58 citations
TL;DR: In this paper, the problems of physical and chemical incompatibility between carbon fiber and the silicon nitride matrix were solved by addition of a small amount of zirconia to the matrix and by low-temperature hot-pressing.
Abstract: The processing of silicon nitride reinforced with carbon fibre was studied. The problems of physical and chemical incompatibility between carbon fibre and the silicon nitride matrix were solved by addition of a small amount of zirconia to the matrix and by low-temperature hot-pressing. The composite material possesses a much higher toughness than hot-pressed silicon nitride. Its work of fracture increased from 19.3 J m−2 for unreinforced Si3N4, to 4770 J m−2; its fracture toughness,K
lc
, increased from 3.7 MN m−3/2 for unreinforced material, to 15.6 MN m−3/2. The strength remains about the same as unreinforced Si3N4 and the thermal expansion coefficient is only 2.51×10−6 ° C−1 (RT to 1000° C). It is anticipated that this composite may be promising because of its mechanical and good thermal shock-resistance properties.
56 citations
TL;DR: The landscape in sand dune areas is characterized by the alternate distribution of sand dunes and interdune lowland, and the unique floras in these areas are some endemic or rare plant species as discussed by the authors.
Abstract: The landscape in sand dune areas is characterized by the alternate distribution of sand dune and interdune lowland, and the unique floras in these areas are some endemic or rare plant species. In recent years, the decrease in plant species richness and the disappearance of some endemic or rare plant species in these areas have been received special attention, which were listed in the Program of International Biodiversity Conservation, and studied in many countries and districts. In this paper, the research progress in these fields was summarized from the aspects of significance of plant diversity conservation, formation mechanisms of plant diversity, ways of plant diversity conservation, roles of plant diversity research in the development of ecological theories, and important issues in operating plant diversity conservation project. To conserve plant diversity in sand dune areas, attentions should be paid to the differences in conservation goals (to maintain high species richness or to conserve endemic or rare species) among different regions, and the balances between the stabilization of active sand and the conservation of endemic or rare species, and the maintenance of high species richness and the conservation of endemic or rare species. It needed also to consider the sand dune and the interdune lowland as a unified landscape unit to explore the impacts of disturbances and habitat fragment on plant diversity.
53 citations
TL;DR: In this article, the general formalism of transient four-wave mixing is developed using the diagrammatic technique of Yee and Gustafson, and applied systematically to two-, three-, and four-level systems.
Abstract: The general formalism of transient four-wave mixing is developed using the diagrammatic technique of Yee and Gustafson, and applied systematically to two-, three-, and four-level systems. The results predict all possible photon-echo phenomena including free-induction decay in the low-intensity limit. Connections to transient saturation spectroscopy and other coherent transient effects can also be made. The treatment can be readily extended to the more general problem of coherent transient optical effects with $n$ waves.
45 citations
TL;DR: A dilute solution of potassium chloride and magnesium sulfate induces oviposition in artificial eggs by the egg parasitoids Trichogramma pretiosum and T. minutum and the ability to obtain large numbers of eggs through the use of this inexpensive solution is a major advance toward the development of diets and the large-scale production of Trichogramsma spp.
Abstract: A dilute solution of potassium chloride and magnesium sulfate induces oviposition in artificial eggs by the egg parasitoids Trichogramma pretiosum and T. minutum. The ability to obtain large numbers of eggs through the use of this inexpensive solution is a major advance toward the development of diets and the large-scale production of Trichogramma spp. in vitro.
44 citations
TL;DR: The dideoxy sequencing technique has been applied to the direct sequencing of large double-stranded DNA molecules with a small single-Stranded primer and proves useful in the sequence analysis of a large number of different mutations in a particular region and in the analysis of eukaryotic DNA cloned in plasmids, phages, and cosmids.
Abstract: The dideoxy sequencing technique has been applied to the direct sequencing of large double-stranded DNA molecules with a small single-stranded primer. For instance, the method was applied to the lambda genome, which contains 48 502 base-pairs (Sanger F, Coulson AR, Hong GF, Hill D & Petersen GB, 1982, J. Mol. Biol., in press), and the coding region for gene W identified. The procedure proves useful in the sequence analysis of a large number of different mutations in a particular region and in the analysis of eukaryotic DNA cloned in plasmids, phages, and cosmids.
43 citations
TL;DR: In this article, the orientation dependence of oxygen adsorption has been investigated on the surface of a cylindrically shaped GaAs single crystal with [1110] being its axis and it is shown that it is possible to prepare all these orientations simultaneously and with reasonable quality by ion bombardment and annealing (IBA).
43 citations
TL;DR: In this article, the microstructures typifying the common mylonites found in the Moine Thrust Zone at Eriboll are presented along with c-axis quartz textures.
Abstract: In this paper, the microstructures typifying the common mylonites found in the Moine Thrust Zone at Eriboll are presented along with c-axis quartz textures. Typical cataclasite microstructures are also depicted. The study revealed that the deformation and softening mechanisms in fault rocks can change with increasing shear strain. It also revealed that strain can be extremely inhomogeneous on the microscale at high shear strains. There is evidence for episodic pulses of brittle behaviour which has been associated with possible seismic behaviour within the zone. The contribution concludes by outlining the microstructural and textural features that can be used to determine the direction of shearing in a mylonite zone.
42 citations
TL;DR: In this article, five sesquiterpene lactones were isolated from Ainsliaea fragrans, two of them being new, and they were used for protein synthesis.
TL;DR: Soliton propagation in nematic liquid crystals under shear is shown to be possible and studied theoretically in this article, including the modulation of monochromatic or white light passing through such a liquid-crystal cell.
Abstract: Soliton propagation in nematic liquid crystals under shear is shown to be possible and studied theoretically. Calculations including those pertaining to the modulation of monochromatic or white light passing through such a liquid-crystal cell are presented. Recent experiments are interpreted accordingly and are in good agreement with the theory presented here.
TL;DR: Gossypol inhibits the activities of pyruvate dehydrogenase complex and Na+, K+- and Mg2+-dependent ATPases of sea urchin spermatozoa, thereby influencing mitochondrial function and flagellar movement.
Abstract: Pyruvate dehydrogenase activity in the mitochondrial fraction obtained from Arbacia punctulata sperm was inhibited by 76%, 40%, and 8% at gossypol concentrations of 50, 20, and 10 μM, respectively. Activities of Mg2+- and Na+, K+-dependent ATPases from sperm mitochondria of Hemicentrotus pulcherrius were also inhibited proportionally to the concentrations of gossypol, ranging from 10 to 80 μM. Gossypol inhibits the activities of pyruvate dehydrogenase complex and Na+, K+- and Mg2+-dependent ATPases of sea urchin spermatozoa, thereby influencing mitochondrial function and flagellar movement.
TL;DR: In this paper, an estimate of the variance of the prediction error for a normal stationary time series based on the periodogram is presented, and it is shown that as T → ∞, the estimate converges almost surely to σ 2, the variance for the best linear predictor.
TL;DR: The orientation dependence of oxygen adsorption has been investigated by XPS and UPS on the surface of a cylindrically shaped GaAs single crystal with [110] as its axis.
TL;DR: The ICP-Spektroskopie für Klarschlamm-Bodenuberwachung hinsichtlich Schwermetallbelastung wird anhand von einigen ausgewahlten Beispielen diskutiert.
Abstract: Die Leistungsfahigkeit der ICP-Spektroskopie fur den routinemasigen Einsatz zur Klarschlamm-Bodenuberwachung hinsichtlich Schwermetallbelastung wird anhand von einigen ausgewahlten Beispielen diskutiert. Ein Vergleich zwischen Konigswasser- und Totalaufschlus fur Klarschlammproben wird gezeigt. Fur die Messungen wurde ein 16-Kanal ICP-Simultanspektrometer verwendet. Es ergab sich, das die Methode fur Uberwachungsaufgaben — auch fur grose Probenzahlen sehr geeignet ist.
TL;DR: In this article, the interaction of small fluctuations with a strong magnetohydrodynamic shock is considered theoretically in the most general situation using an ideal model and an analytical treatment of the cutoff conditions for penetration of the upstream fluctuation through the bow shock is presented.
Abstract: The interaction of small fluctuations with a strong magnetohydrodynamic shock is considered theoretically in the most general situation using an ideal model An analytical treatment of the cutoff conditions for penetration of the upstream fluctuation through the bow shock is presented The situation in which there exist unique solutions of the interaction is investigated quantitatively Numerical examples of the interaction of waves in the solar wind with the terrestrial bow shock are given to illustrate the refracted waves to be found in the earth’s magnetosheath
TL;DR: In this article, the minimum problem of SU( n ) symmetric potential which has number of Higgs in fundamental, adjoint, second-rank symmetric and antisymmetric tensor representations is discussed.
TL;DR: In this article, the equivalence between permutability of the Backlund transformation and the involution of the conserved densities of the sine-Gordon equation was shown.
Abstract: Letu′=Bau be the Backlund transformation of the sine-Gordon equation, we prove that
$$B_{a + \varepsilon } B_a^{ - 1} u = u + \varepsilon \sum\limits_{n = 0}^\infty {2D^{ - 1} } \frac{{\delta G_{n + 1} }}{{\delta u}}a^{2n} ,$$
where {Gn} is an infinite set of conserved densities of the sine-Gordon equation and ηn≡D−1δGn/δu are just the symmetries obtained by Olver [17]. Basing upon this expansion, we prove the equivalence between the permutability of the infinitesimal Backlund transformations and the involution of the conserved densities of the sine-Gordon equation.
TL;DR: This note points out that texture analysis techniques are applicable, in principle, to three-dimensional data arrays and to arrays of range (or terrain elevation) data.
TL;DR: In this paper, a Si:Cl:H film is described and the existence of chlorine atoms is identified by infrared and backscattering analyses, and it is found that Si3HCl configuration is dominant.
TL;DR: In this article, ESCA and AES were combined with ion sputtering to study compositional structure of MIS polycrystalline silicon solar cells, and a Cr2O3 layer formed during deposition of the metallic Cr layer was observed by studying the ESCA-sputtering profiles.
TL;DR: In this article, the authors observed several differential pulse polarographic peaks in buffered or unbuffered solutions in the presence of ammonium and Yb(III) ions and compared these with the results on classical polarography for nitrate, nitrite, and hydroxylamine respectively.
TL;DR: In this paper, the effects of the growth conditions on the properties of epitaxial layers are given. And the electrical properties of the epi-layer depend not only on the contaminating impurities in the growth solution, but also on the epitaxia growth conditions in connection with incorporating impurities and defects.
TL;DR: In this article, three types of linear polarization resistance (LPR) may provide an approximate value of polarization resistance for estimating the corrosion current density icorr: an anodic LPR, Ra, a cathodic L PR, Rc and a bi-directional LPR Rb.
01 Jan 1982
01 Jan 1982