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Study on the Relationship Between Sex Differentiation and Ethylene in Ramie

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Agricultural Sciences in China 2009年第4期8卷 418-423页

作者： XING Hu-cheng SHE Wei LUO Zhong-qin QIN zhan.jun jie Yu-cheng Ramie Research Institute Hunan Agricultural University Changsha 410128 P.R.China Institute of Bast Fiber Crops Chinese Academy of Agricultural Sciences Changsha 410205 P.R. China

To explore the role of ethylene in sexual determination in ramie, the ethylene release rates in ramie stem apex of different sex, bud of the same node in female and hermaphrodite ramie in the second crop, and single inflorescence of different sex in hermaphrodite ramie were measured by gas chromatography. Effects of two ethylene inhibitors on sex expression in ramie were investigated. The ethylene release rate of stem apex was higher in the second crop or female ramie than that in the third crop or hermaphrodite ramie during growth. Although ethylene release rates between lower nodes and higher nodes were little different, it was lower in the middle nodes in hermaphrodite ramie. The ethylene release rates were higher in the higher nodes of female ramie at the second crop. At the third crop, the ethylene release rates were higher in lower nodes, lower in middle nodes and then highest in higher nodes in female ramie. However, an opposite ethylene release pattern was observed in hermaphrodite ramie. The ethylene release rate was higher in female flower than male flower and mixed inflorescence in hermaphrodite ramie. The male flower could be distinctly induced by AVG （aminooethoxyvinylglycine）. The node of the first male flower, percentage of female flowers and ratio of female flowers to male in ramie were evidently depressed by AVG in contrast to water. The percentage of mixed male and female flowers was also increased and the percentage of female flower decreased by spraying AgNO3. There was a close relationship between sexual differentiation and ethylene release rate in ramie. The female ramie could be induced by high ethylene release rate. The female flower could be inhibited by AVG and AgNO3. AVG at a concentration of 300 mg L^-1 was most effective.

关键词： ramie [Boehmeria nivea (L.) Gaud] sex ethylene

Stability and Hopf Bifurcation Analysis on a Numerical Discretization of the Distributed Delay Equation

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Chinese Physics Letters 2012年第5期29卷 7-10页

作者： WU jie zhan.Xi-Sheng zhan. Xian-He GAO Hong-Liang College of Mechatronics and Control Engineering Hubei Normal UniversityHuangshi 435002

A kind of discrete logistic model with distributed delays obtained by the Euler method is investigated,where the discrete delay Τ is regarded as a *** analyzing the associated characteristic equation,it is found that the stability of the positive equilibrium and Hopf occurs when Τ crosses some critical *** the explicit formulae which determine the stability,direction and other properties of the bifurcating periodic solution are derived by using the theory of normal form and center ***,numerical simulations are performed to verify and illustrate the analytical results.

关键词： parameter. value. Hopf

Numerical Simulation for Shallow Strata Stability of Coral Reef in the Southwest of Yongshu Reef(South China Sea)

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Journal of Ocean University of China 2018年第4期17卷 763-772页

作者： TANG Qinqin zhan. Jinchang FENG Yingci LI Jian YAO Yantao SUN jie zhan.Wenhuan Key Laboratory of Ocean and Marginal Sea Geology CASGuangzhou 510301China University of Chinese Academy of Sciences Beijing 100049China

In recent years, infrastructure construction on coral reefs has been increasingly developed. Therefore, the shallow strata stability of coral reefs in the South China Sea should be evaluated. This study aims to investigate the profiles for the shallow strata of coral reefs in the southwest of the Yongshu Reef, particularly in the hydrodynamic marine environment, and to establish a geological model for numerical simulation using Geo-Studio. The shallow strata of the coral reefs include mass gravel, sand gravel, mid-coarse sand, silty sand, fine sand, and reef limestone. The shallow reef slope near the lagoon is similar to a ‘layer cake', in which the side close to the sea is analogous to a ‘block cake'. The simulation results showed that coral reef stability depends on wave loads and earthquake strength and on the physical properties of coral reefs. The factor of safety for the outer reef is greater than 10.0 under static, wave, and seismic conditions; this indicated that the outer reefs were less affected by waves and earthquakes. However, the factor of safety next to the lagoon varied from 0.1 to 5.3. The variation was primarily caused by the thick strata of coral reefs close to the sea(reef limestone, typically with the thickness > 10 m and equivalent to a block). The soil and rock layers in the coral reef strata with thicknesses < 10 m showed weak engineering geological characteristics. Our findings can provide useful information to future construction projects on coral reefs.

关键词： coral reefs rock mass structure stability evaluation numerical simulation

A COMPARISON OF THE RETRIEVAL OF ATMOSPHERIC TEMPERATURE PROFILES USING OBSERVATIONS OF THE 60 GHZ AND 118.75 GHZ ABSORPTION LINES

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Journal of Tropical Meteorology 2018年第2期24卷 151-162页

作者： HE Qiu-rui WANG Zhen-zhan.HE jie-ying zhan. Lan-jie Key Laboratory of Microwave Remote Sensing National Space Science Center Chinese Academy of SciencesBeijing 100190 China University of Chinese Academy of Sciences Beijing 100049 China

The Microwave Temperature Sounder-Ⅱ(MWTS-Ⅱ) and Microwave Humidity and Temperature Sounder(MWHTS) onboard the Fengyun-3 C(FY-3 C) satellite can be used to detect atmospheric temperature profiles. The MWTS-II has 13 temperature sounding channels around the 60 GHz oxygen absorption band and the MWHTS has 8 temperature sounding channels around the 118.75 GHz oxygen absorption line. The data quality of the observed brightness temperatures can be evaluated using atmospheric temperature retrievals from the MWTS-Ⅱ and MWHTS observations. Here, the bias characteristics and corrections of the observed brightness temperatures are described. The information contents of observations are calculated, and the retrieved atmospheric temperature profiles are compared using a neural network(NN) retrieval algorithm and a one-dimensional variational inversion(1 D-var) retrieval algorithm. The retrieval results from the NN algorithm show that the accuracy of the MWTS-Ⅱ retrieval is higher than that of the MWHTS retrieval, which is consistent with the results of the radiometric information analysis. The retrieval results from the 1 D-var algorithm show that the accuracy of MWTS-Ⅱ retrieval is similar to that of the MWHTS retrieval at the levels from 850-1,000 h Pa, is lower than that of the MWHTS retrieval at the levels from 650-850 h Pa and 125-300 h Pa, and is higher than that of MWHTS at the other levels. A comparison of the retrieved atmospheric temperature using these satellite observations provides a reference value for assessing the accuracy of atmospheric temperature detection at the 60 GHz oxygen band and 118.75 GHz oxygen line. In addition, based on the comparison of the retrieval results, an optimized combination method is proposed using a branch and bound algorithm for the NN retrieval algorithm, which combines the observations from both the MWTS-Ⅱand MWHTS instruments to retrieve the atmospheric temperature profiles. The results show that the optimal combination can further i

关键词： Fengyun-3C satellite Microwave Temperature Sounder-II microwave humidity and temperature sounder one-dimensional variational retrieval algorithm neural networks retrieval algorithm

Approximation of weak sense stationary stochastic processes from local averages

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Science China Mathematics 2007年第4期50卷 457-463页

作者： zhan.jie SONG Wen-chang SUN Shou-yuan YANG Guang-wen ZHU School of Science Tianjin UniversityTianjin 300072China Department of Mathematics and LPMC Nankai UniversityTianjin 300071China National Ocean Technology Center Tianjin 300111China

We show that a weak sense stationary stochastic process can be approximated by local averages. Explicit error bounds are given. Our result improves an early one from Splettst?sser.

关键词： sampling theorem weak sense stationary stochastic processes local averages average sampling 42C15 60G10 94A20

Extraordinary propagation characteristics of electromagnetic waves in one-dimensional anti-PT-symmetric ring optical waveguide network

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Chinese Physics B 2020年第6期29卷 164-170页

作者： jie-Feng Xu Xiang-Bo Yang Hao-Han Chen zhan.Hong Lin Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices School of Information and Optoelectronic Science and EngineeringSouth China Normal UniversityGuangzhou 510006China

In this paper, we design a one-dimensional anti-PT-symmetric ring optical waveguide network(1 D APTSPROWN).Using the three-material network equation and the generalized Floquet–Bloch theorem, we investigate its photonic mode distribution, and observe weak extremum spontaneous anti-PT-symmetric breaking points(WBPs) and strong extremum spontaneous anti-PT-symmetric breaking points(SBPs). Then the transmission spectrum is obtained by using the threematerial network equation and the generalized eigenfunction method. The 1 D APTSPROWN is found to generate ultrastrong transmission near SBPs and ultra-weak transmission near WBPs and SBPs, with the maximal and minimal transmissions being 4.08× 1012 and 7.08× 10-52, respectively. The maximal transmission has the same order of magnitude as the best-reported result. It is not only because the distribution of photonic modes generated by the 1 D APTSROWN results in the coupling resonance and anti-resonance, but also because the 1 D APTSROWN composed of materials whose real parts of refractive indices are positive and negative has two kinds of phase effects, which results in the resonance and antiresonance effects in the same kind of photonic modes. This demonstrates that the anti-PT-symmetric and PT-symmetric optical waveguide networks are quite different, which leads to a more in-depth understanding of anti-PT-symmetric and PT-symmetric structures. This work has the potential for paving a new approach to designing single photon emitters,optical amplifiers, and high-efficiency optical energy saver devices.

关键词： waveguides optical materials metamaterials

Facile and efficient synthesis of 5,7-disubstituted thiazolo[5,4-d] pyrimidine-4,6(5H,7H)-diones

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Chinese Chemical Letters 2012年第6期23卷 695-698页

作者： Liang Chen zhan.Mei Li jie Zhou Hong Rui Song Bai Ling Xu Beifing Key Laboratory of Active Substance Discovery and Druggability Evaluation Institute ofMateria Medica Chinese Academy of Medical Sciences ＆ Peking Union Medical College Beijing 100050 China Department of Pharmacy Engineering Shenyang Pharmaceutical University Shenyang 110016 China

A facile and efficient approach was developed to access 5, 7-disubstitued thiazolo[5,4-d]pyrimidine-4, 6（5H, 7H）-diones through condensation of N-substituted 5-amino-4-carbethoxythiazole with structurally diverse isocyanates in the presence of sodium hydride. The easy availability of substrates and tolerance of structural diversity in this reaction make it attractive to be used for construction of libraries in drug discovery process.

关键词： Thiazolo[5,4-d]pyrimidine-4 6(5H 7H)-dione Isocyanate Isothiocyanate Sodium hydride

Electronic, Vibrational, and Superconducting Properties of High-Pressure Metallic SiH4： ab initio Calculations

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Chinese Physics Letters 2010年第1期27卷 227-230页

作者：闫岩宫杰宗占国 School of Materials Science and Engineering Changchun University of Science and Technology Changchun 130022 Applied Physics Institute Changchun University Changchun 130022 Institute of Science and Engineering China Jiliang University Hangzhou 310018

We extensively explore the experimentally proposed metallic structure of hcp P63 for the hydrogen rich compound, SiH4. It is found that the lattice dynamic of this structure is severely unstable. By freezing the soften mode, an orthorhombic Pbcn structure is discovered to be dynamically stable up to 226GPa. Within the conventional BCS theory, the calculated critical temperature Tc within the proposed Pbcn structure is 16.5K at 188GPa, in good agreement with the experimental result （17.5K）. Thus, we propose that the current predicted orthorhombic phase is a better candidate for the metallic phase of SiH4.

关键词： Metals Experimentation

A quantitative benefit evaluation of code search platform for enterprises

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Science China(Information Sciences) 2020年第9期63卷 58-60页

作者： zhan.SHI jie TANG Hao YU Yongxu XING Zhiwei LIU Wei BAI Tao LI Baidu (China) Co. Ltd Baidu Online Network Technology (Beijing) Co. Ltd

Dear editor,With the size and complexity of modern software growing, developers need more efficient tools to accomplish all kinds of routine tasks, such as coding,compiling, and analyzing program structure [1].Among t... 详细信息

关键词： code search efficiency evaluation software engineering efficiency engineer development platform