最新刊期
卷 26 ， 期 4 ， 1987
- 摘要：Let denote the class of all standard p-functions. for any pe, 0=to≤t1nnns15s1ssss1z012n+1n+1r2r0
- 73
- |
- 17
- |
- 0
发布时间：2023-12-11 - 摘要：The characteristic theorem for the best interpolation points of operator spline functions of order two is proved for strictly convex (concave) interpolated functions. The theoretical explanation about denser distribution of the best interpolation points near singlular point of interpolated function is presented. For a few simple interpolated functions, their best interpolation points are given according to the characteristic theorem.关键词：Operator spline;interpolation;Best knots
- 53
- |
- 17
- |
- 0
发布时间：2023-12-11 - 摘要：The nonlinear bifurcation for the riser under the effect including tension, ovcrpull and steady flow, is discussed. The singular perturbation method is employed to solve the perturbed bifurcation problem with multiple independent parameters. Bifurcation curve surfaces which model imperfections aer obtained. Their stab ility is also investigated.
- 56
- |
- 21
- |
- 0
发布时间：2023-12-11 - 摘要：The normal form of the lincar elliptic systems of second order in Petrovskii sense with two variations and two unknow functions in divergence form is that Assume that the matrix -D(x) is positive definite and its least eigenvalueIn this paper we prove that if γ>0, then Dirichlet probfems of the elliptic systems in Petrovskii sense exist unigue. solutipn. Particularly, if Bi(x)=Ci(x) and D(x) is seminegative definite there is an unique solution关键词： Linear elliptic systems;Dirichlit problem;Bounded and coercive;bilinear form
- 48
- |
- 18
- |
- 0
发布时间：2023-12-11 - 摘要：The physical mechanism of the training process of TWSME has been studied in a Ni-49.7at%Ti alloy, by utilizing the measurements of electric resistance change, internal friction, elastic modulus and distortion strain for the fully trained specimen as well as un-trained specimen. It has been verified that a complete two way shape memory effect obtained through training process was provided by the I/C (incommensurate/commensurate) phase transformation in this alloy. The changes of electric resistance and resistant force of transformation have been studied and the essence of the training process is discussed. The substantive point of the training process is that under combined action of temperature and stress field, the I/C transformation is induced, the transformation resistant force tends to decrease and stabilize, making the transformation process reversible completely in a specific way. The specimen then possesses the two way shape memory effect.关键词：NiTi alloy;Two way shape memory effect;Training process;Transformation resistant force;I/C phase transformation
- 94
- |
- 25
- |
- 0
发布时间：2023-12-11 - 摘要：Positron annihilation technique gives unique information for electronic structure of ferroelectric crystals. Anomalous change of property and structure parameters was compared with the theory of internal rotation of oxygen octahedra in lithium niobate single crystal. The experimental results can not be explained from the viewpoint of lattice dynamics. In temperature range of 20 to 85℃, the life-time spectrum of positron in LN has two major components. The ano-222关键词：Positron;Lithium niobate;Oxygen octahedra;Internal rotation;Relaxation
- 96
- |
- 19
- |
- 0
发布时间：2023-12-11 - 摘要：The ancient Zhaoqing was originally a hub of water transportion linking the Pearl River Delta and the Central China. Due to its typical location and favourable transport conditions, Zhaoqing was once established as a provincial capital administrating both Guangdong Province and Guangxi Province during the Ming dynasty and Ching dynasty. The development of Zhaoqing was declined after and Ching dynasty. The development of Zhaoqing was declined after the building up of the Railroad Canton-Wuhan and the Railroad Hunan-Guangxi in its surrounding area because the city’s hinterlands were divided by those railroads. The Railroad Sanshui-Maoming and the Xijiang Bridge are recently built pass through Zhaoqing. It is believed that the city’s transportation linkage with its hinterlands will therefore be improved and the growth of this city will be accelerated. The corresponding changes in the city’s functions and land use pattern are finally predicated and several measures which should be taken in the city’s planning are proposed.
- 60
- |
- 23
- |
- 0
发布时间：2023-12-11 - 摘要：Dendroid graptolites of the late Cambrian and early Ordovican from Taoyuan, Hunan are dealt with in this paper. They consist of 40 species and subspecies assigned to 9 genera, of which there are 11 new species. At this locality Late Cambrian and Tremadoc stage (early Ordovician) contain four graptolite zones as follows: Heterograptus zone, Anisograptus zone, Dictyograptus flabelliformis zone, Dictyograptus wutingshanensis zone. These dendroids found from the key strata are very importent for the study and correlation of Cambrian-Ordovician boundary
- 65
- |
- 22
- |
- 0
发布时间：2023-12-11 - 摘要：A new synthetic method of dehydropeptides, by direct coupling of N-protected amino acids or N-protected peptides with β-hydroxy -α-amino acid esters in the presence of three equivalents of each of triphenylphosphine, carbon tetrachloride, and triethylamine or ethyl diisopropylamine, was devcloped. Compounds synthesized by this method were Boc-DL-Ile-⊿But-oMe, Boc-DL-Ile-⊿Ala-oMe, Boc-DL-Val⊿Ala-OMe, Boc-L Ile-DL-Val(Thz)-⊿But-oMe, and Boc-L-Ile-DL-Val(Thz)-⊿Ala -oMe. In the case of L-threone methyl ester, only Z-dehydroamino acid residue was observed. A possible mechanism was proposed. It was believed that the Nprotected amino acid or N-protected peptide was coupled first with β-hydroxy -α-amino acid ester, forming a peptide having a β-hydroxyamino acid residue at the C terminal, and then dehydration of the newly formed peptide gave dehydropeptide. The same reagents were used to synthesize peptide oxazolines. The key factor affecting reaction directions was the acidity of the protons at the α-C-H bond and at the N-H bond.关键词：Dehydropeptide;Dehydroamino acid;Oxazolinc
- 78
- |
- 22
- |
- 0
发布时间：2023-12-11 - 摘要：A further research was made to the 13 forest communities on Hong Kong island by using fuzzy cluster, reciprocal averaging (RA) and R-Principal component analysis (R-PCA). The results show that fuzzy cluster is suitable for the classfication of the lower subtropical forests, especially, the higher classficational units. The RA ordination indicates the relations between 13 forest communities and 60 species distribution in these forest communities and it seems better and more significant than the other methods in this field. And R-PCA illustrated the relationship between the dominant and subordinate species.关键词： Hong kong island;Forest communities;Fuzzy cluster;Reciprocal averaging ordination;R-Principal component analysis
- 81
- |
- 27
- |
- 0
发布时间：2023-12-11 -
- 摘要：The application of nitrification inhibior CP on the Citrus was studied by using the isotope technique.1. The rate of utilization of the nitrogenous fertilizer was increased when it was used in combination with the nitrification inhibitors.2. The number of the length of shoots, nitrogen content of leaf, amount of ammonium nitrogen pH in soil and the yield of fruit were increased, after the incorporation of nitrification inhibitor CP into nitrogenous fertilizer.3. There was no effect on the quality of fruits in citrus with the application of nitrification inhibitors. The residue of nitrification inhibitor CP in fruits of citrus was very low.
- 81
- |
- 21
- |
- 0
发布时间：2023-12-11 - 摘要：The X-ray diffraction intensity vs. temparature curves have been measured directily by method of constant angle scanning for parent phase, martensite and R-phase in NiTi alloy respectively. On heating and cooling,two stages have been found in variation of X-ray diffraction intensity of parent phase. On cooling, the first stage of diffraction intensity reduction corresponds to lattice unstability, but the second one corresponds to normal martensitic transition and R- transition. The two stage curve of diffraction intensity becomes to one stage curve under action of load. This phenomenon can be explained by transition temperaturc shifting when alloy undergoes a thermal cycling under load.
- 56
- |
- 20
- |
- 0
发布时间：2023-12-11 - 摘要：he gravitational wave antenna must be supported during the operation, in order to cancel its weight. The ideal supported points are nodes of antenna. However, for a variety of reasons, sometimes the supported points may deviate from the nodes of antenna, and that must influence Q factor of the antenna. In this paper, we have considered the supporting formalism which influence on Q factor of antenna in general aspect, and have obtained some significative results.
- 48
- |
- 18
- |
- 0
发布时间：2023-12-11 - 摘要：This paper reports the syntheses of five analogues of subergorgic acid: methyl ester of subergorgic acid （3）, 9-hydroxyl subergorgic acid （4）, 2,3-epoxidesubergorgic acid（5）, 8-hydroxyl-⊿7,8-ene-subergorgic acid （7） and its methyl ester（6）.An attempt has been made to survey the relationship between the structure of subergorgic acid and its bioactivity. Compounds （3） and （4）, though similar to subergorgic acid in structure, possess almost no toxicity. As soon as an epoxy or a double bond is functionalized to the α,β-position of the carboxyl or the earbonyl group respectively, its toxicity almost disappears too, Therefore. it can be thought that the carboxyl and carbonyl groups are responsible for the bioactivity of subergorgic acid.关键词：Subergorgic acid;Analogues of subergorgic acid;Neurotoxin
- 65
- |
- 25
- |
- 0
发布时间：2023-12-11 - 摘要：A Pseudomonas species desiganted as S7, was isolated from polluted environment by using a minimal medium containing salicylate as the sole carbon source and a rich medium containing HgCl2The organism could degrade and utilize phenol, salicylate, benzoic acid or catechal as the sole carbon source and was resistant to HgCl2when it was grown in a rich medium. The minimal inhibitory concentration of phenol for the bacterium was 7.4 mM. The degradation of phenol and salicylate by S7 Was inducible and regulated by catechal or its catabolites as a repressor.关键词：Pseudomons;Phenol degrading bacteria;Merctiry-resistant bacteria
- 54
- |
- 22
- |
- 0
发布时间：2023-12-11
- Postal code：510275
- Tel：020-84112585，84113223 Email：xuebaozr@mail.sysu.edu.cn
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备09064830号-19
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0