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Search Results: 1 - 10 of 127167 matches for " Li Liansheng "
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Back-propagation network improved by conjugate gradient based on genetic algorithm in QSAR study on endocrine disrupting chemicals
Li Ji,XiaoDong Wang,XuShu Yang,ShuShen Liu,LianSheng Wang
Chinese Science Bulletin , 2008, DOI: 10.1007/s11434-007-0484-6
Abstract: Since the complexity and structural diversity of man-made compounds are considered, quantitative structure-activity relationships (QSARs)-based fast screening approaches are urgently needed for the assessment of the potential risk of endocrine disrupting chemicals (EDCs). The artificial neural networks (ANN) are capable of recognizing highly nonlinear relationships, so it will have a bright application prospect in building high-quality QSAR models. As a popular supervised training algorithm in ANN, back-propagation (BP) converges slowly and immerses in vibration frequently. In this paper, a research strategy that BP neural network was improved by conjugate gradient (CG) algorithm with a variable selection method based on genetic algorithm was applied to investigate the QSAR of EDCs. This resulted in a robust and highly predictive ANN model with R 2 of 0.845 for the training set, q 2 pred of 0.81 and root-mean-square error (RMSE) of 0.688 for the test set. The result shows that our method can provide a feasible and practical tool for the rapid screening of the estrogen activity of organic compounds.
Comparison of Seven Approaches in Constructing Ontology
构建知识本体方法体系的比较研究

Li Jing Meng Liansheng,
李景
,孟连生

现代图书情报技术 , 2004,
Abstract: There are seven approaches of constructing ontology having been introduced in this article. Through comparing them with different aspects, their advantages, shortcoming and distinctions been disclosed.
Triphenylbis[4-(trifluoromethyl)benzoato-κO]antimony(V)
Li Quan,Handong Yin,Liansheng Cui,Minglei Yang
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809017449
Abstract: The title complex, [Sb(C6H5)3(C8H4F3O2)2], is located on a twofold axis defined by the metal center and two C atoms of a coordinated phenyl group. The environment of the Sb atom approximates a trigonal-bipyramidal geometry, with the axial positions occupied by the O atoms of symmetry-related 4-(trifluoromethyl)benzoate ligands. In this ligand, the CF3 group is disordered by rotation about the C—C bond and the F atoms are distributed over two sets of sites with occupancies of 0.62 (3) and 0.38 (3). In the crystal, molecules are assembled in a three-dimensional framework through weak C—H...O hydrogen bonds.
catena-Poly[[diaquacalcium(II)]-di-μ-2-chloronicotinato]
Li Quan,Handong Yin,Liansheng Cui,Minglei Yang
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536808044267
Abstract: The itle compound, [Ca(C6H3ClNO2)2(H2O)2]n, contains polymeric chains extending along [100] that are generated by inversion centres. The Ca2+ ions are bridged by 2-chloronicotinate groups and exhibit an eight-coordination by six carboxylate O atoms of four different 2-chloronicotinate ligands and two O atoms of water molecules. In the crystal structure, intermolecular O—H...O, O—H...N and C—H...O hydrogen bonds result in the formation of a supramolecular network structure. The π–π contacts between the 2-chloronicotinate rings [centroid–centroid distances = 3.875 (3) and 3.701 (3) ] may further stabilize the structure.
catena-Poly[[(N,N-diethyldithiocarbamato-κ2S:S′)phenylbismuth(III)]-μ-chlorido]
Liansheng Cui,Handong Yin,Minglei Yang,Li Quan
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536808032820
Abstract: In the title compound, [Bi(C6H5)(C5H10NS2)Cl]n, the Bi atom is coordinated by two S atoms of the dithiocarbamate ligand, one C atom of the phenyl group and one Cl atom in a four-coordinated tetrahedral configuration. Molecules are linked by Cl atoms to form a zigzag chain extending in the c direction.
Di-μ-hydroxido-bis[aquatrichloridotin(IV)] diethyl ether disolvate
Minglei Yang,Handong Yin,Li Quan,Liansheng Cui
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536808032832
Abstract: The title compound, [Sn2Cl6(OH)2(H2O)2]·2C4H10O, consists of a centrosymmetric molecule and two additional solvent molecules and has an infinite two-dimensional network extending parallel to (101). The Sn atom is six-coordinate with a distorted octahedral geometry. Additional O—H...O hydrogen bonding leads to stabilization of the crystal structure.
2-[(2-Hydroxy-1-naphthyl)methyleneamino]-1,3-benzothiazole
Liansheng Cui,Handong Yin,Minglei Yang,Li Quan
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536808029644
Abstract: In the title compound, C18H12N2OS, the dihedral angle between the mean planes of the aromatic ring systems is 7.26 (8)°. There is an intramolecular O—H...N hydrogen bond, forming a six-membered ring. In the crystal structure, intermolecular C—H...N hydrogen bonds link the molecules into a one-dimensional chain.
Research on a Scroll Expander Used for Recovering Work in a Fuel Cell
Gao Xiaojun,Li Liansheng,Zhao Yuanyang,Shu Pengcheng
International Journal of Thermodynamics , 2004, DOI: 10.5541/ijot.120
Abstract: The energy of the exhausted high-pressure air from a proton exchange membrane (PEM) fuel cell can still be recovered. The performance of the scroll expander used for recovering this energy is studied in this paper. A numerical simulation of the expander is presented, and then the simulated results are compared with that of the experiment results gleaned from the prototype of the expander. The matching of the flows and pressure characteristics between the compressor-expander (C-E) is also discussed. Finally, this paper points out that leakage has a significant effect on the volumetric efficiency, the quantity of recovered work, and other performance indicators of the scroll expander. The matching of the C-E is a key factor in the practical application of this system.
The Modification of the Valves of a Refrigeration Piston Compressor due to the Refrigerant Change
Zhao Yuanyang,Li Liansheng,Guo Bei,Shu Pengcheng
International Journal of Thermodynamics , 2003, DOI: 10.5541/ijot.105
Abstract: Compressor and refrigerant play key roles in a refrigeration system. Owing to the de-mands of environment protection, the CFCs and HCFCs refrigerants will be phased out in a short time, and new refrigerants such as R600, R134a and R407C will be used. As the new refrigerant is selected, the motion regularity of the valves will be changed. The motion regularity of the ring valves of a 2-stage refrigerating piston compressor is simulated, and the calculations are done respectively with refrigerants R717 (ammonia), R22 and R134a. The results show that refrigerants and working conditions of a compressor have a direct effect on the motion of the ring valves. Comparing the original design parameters of the ring valves with the modified ones, the former are effective for the HCFC refrigerants, the latter have perfect motion of the valves for the new refrigerants, and the refrigeration system performance parameters, such as input power, the refrigerating quantity and the COP value, are also better. Service life test of the compressor system using the ring valves has been done for R717. The compressor using the modified ring valves has a life exceeding 8000 hours. Hence, the valve design should consider the influences of the refrigerant.
Pulsar observations in China
Liansheng Kang
Chinese Science Bulletin , 2002, DOI: 10.1360/02tb9064
Abstract: The development history and achievement of pulsar observation in China were introduced. The history is very short, only ten years. The cooperation program about pulsar timing observation at 18 cm using a 25-m radio telescope of UAO between China, Australia and Great Britain has been carried out since 1997. Some scientific results such as glitch, model changing, interstellar scintillation and the spectra of pulsar have been obtained. The plans of development of the pulsar observation were also introduced using Chinese radio telescopes.
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