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Search Results: 1 - 10 of 25711 matches for " Zhengping Cheng "
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A Solution for Cross-docking Operations Planning, Scheduling and Coordination  [PDF]
Zhengping Li, Wei He, Cheng Hwee Sim, Chong Chuan Chen
Journal of Service Science and Management (JSSM) , 2012, DOI: 10.4236/jssm.2012.52014
Abstract: Crossdocking is defined as an operational strategy that moves items through consolidation centers or cross docks without putting them into storage. As the need to move inventory faster increases, more logistics managers are turning to crossdocking but the ability to execute such strategy well depends on good planning, dynamic scheduling and coordina-tion. This paper introduces our research and development work on cross docking solution in three aspects: optimized planning on container grouping, clustering, sequencing and allocating containers to docks; real-time scheduling handles the dynamics of container arrivals and actual pallet transfers; and cross-docking coordination conducts real-time task assignment/sequencing and resource management to deal with dynamic changes.
Integration of rolling circle amplification and cationic conjugated polymer for the homogeneous detection of single nucleotide polymorphisms
ZhiYuan Tang,YongQiang Cheng,Qing Du,HongXia Zhang,ZhengPing Li
Chinese Science Bulletin , 2011, DOI: 10.1007/s11434-011-4663-0
Abstract: A novel, homogeneous and sensitive assay for the detection of single nucleotide polymorphisms (SNPs) by integration of rolling circle amplification (RCA) and cationic conjugated polymer (CCP) has been developed and tested. Mutant DNA serves as the template for specifically circularizing a padlock probe (PLP) with a sequence that is complementary to the mutant DNA. Afterwards, the mutant DNA directly acts as the primer to initiate the RCA reaction in the presence of phi29 DNA polymerase that generates a long, tandem single-strand DNA product. During the RCA reaction, fluorescein-labeled dUTPs are incorporated into the RCA products. When the CCP is introduced, efficient FRET from CCP to fluorescein occurs as a result of the strong electrostatic interactions between the CCP and the DNA produced by RCA. The wild-type DNA contains a single base mismatch with PLP with the result that the PLP is not circularized, RCA is not triggered and inefficient FRET results. By measuring the change of the emission intensities of CCP and fluorescein, it was possible to detect the SNP in a homogeneous manner. The method is sensitive and specific enough to detect 0.1 pmol/L mutant DNA and to determine a mutant allele frequency as low as 2.0%.
Novel Co-Mg-Al-Ti-O catalyst derived from hydrotalcite-like compound for NO storage/decomposition
Jie Cheng,Xiaoping Wang,Chunyan Ma,Zhengping Hao,
Jie Cheng
,Xiaoping Wang,Chunyan M,Zhengping Hao

环境科学学报(英文版) , 2012,
Abstract: Catalysts of Co1.5Mg1.5/Al0.9Ti0.1O and Co1.5Mg1.5/AlO were successfully prepared by calcinations of corresponding hydrotalcite-like compounds at 800℃ for 4 hr. The derived oxides were of spinel phase and a small quantity of Ti substitution did not change the crystal purity. Their catalytic performance for the NO storage/decomposition was investigated. Ti incorporation enhanced the NO decomposition activity while has an opposite effect on the storage capacity of catalyst. In situ FT-IR spectra of the catalysts showed that the final adsorption species on the catalysts was coordinated nitrates/nitrites. In addition, NO storage/decomposition mechanism has been discussed on the basis of these observations.
Conditionally Suboptimal Filtering in Nonlinear Stochastic Differential System  [PDF]
Tongjun He, Zhengping Shi
Applied Mathematics (AM) , 2011, DOI: 10.4236/am.2011.26101
Abstract: This paper presents a novel conditionally suboptimal filtering algorithm on estimation problems that arise in discrete nonlinear time-varying stochastic difference systems. The suboptimal state estimate is formed by summing of conditionally nonlinear filtering estimates that their weights depend only on time instants, in contrast to conditionally optimal filtering, the proposed conditionally suboptimal filtering allows parallel processing of information and reduce online computational requirements in some nonlinear stochastic difference system. High accuracy and efficiency of the conditionally suboptimal nonlinear filtering are demonstrated on a numerical example.
A Quantity Discount Pricing Model Based on the Standard Container under Asymmetric Information  [PDF]
Zhengping DING, Keyi WANG
Journal of Service Science and Management (JSSM) , 2009, DOI: 10.4236/jssm.2009.23026
Abstract: A supply chain system is studied, in which the information about the retailer’s storage cost is usually asymmetric. This paper studies the inventory control in the system and presents a quantity discount pricing model for inventory coordination based on the standard container, a transport tool from the supplier to the retailer with a fixed size. First, it investigates the inventory models under full information. Before inventory coordination, the supplier and the retailer my-opically choose their lot sizes, which is not the optimal decision for the whole system. Then, it presents an incentive scheme under asymmetric information from the point of view of the supplier. It also discusses the solution and the distribution of the incremental profits after the incentive scheme is adopted by both the supplier and the retailer. A con-stant in the model, which affects the distribution of the incremental profits, is optimized for the supplier by using numerical analysis. Finally, an example illustrates the application of the model. After inventory coordination, both the supplier and the retailer have a positive incremental profit.
Synthesis and Characterization of Well-Defined Soluble - and -Functionalized Polymers via RAFT Copolymerization
Chengchao Wang,Wei Zhang,Nianchen Zhou,Yansheng Qiu,Zhengping Cheng,Xiulin Zhu
International Journal of Polymer Science , 2010, DOI: 10.1155/2010/340926
Abstract: The reversible addition-fragmentation chain transfer (RAFT) copolymerizations of 2-((8-hydroxyquinolin-5-yl)methoxy)ethyl methacrylate (HQHEMA) with styrene (St) or methyl methacrylate (MMA) were successfully carried out in the presence of 2-cyanoprop-2-yl dithionaphthalenoate (CPDN). The polymerization behaviors showed the typical living natures by the first-order polymerization kinetics, the linear dependence of molecular weights of the polymers on the monomer conversions with the relatively narrow molecular weight distributions , and the successful chain extension experiments. The soluble polymers having tris(8-hydroxyquinoline)aluminum ( ) and bis(8-hydroxyquinoline) znic(II) ( ) side chains were obtained via complexation of the polymers with aluminium isopropoxide or zinc acetate in the presence of monomeric 8-hydroxyquinoline, which had strong fluorescent emission at 520?nm. The obtained polymers were characterized by GPC, NMR, UV-vis, and fluorescent spectra. 1. Introduction In recent years, organic electroluminescence (EL) display devices have attracted more intensive attention as a promising technology for flat panel display [1]. Many emitting materials, including low-weight molecules and polymers, have been designed and utilized in fabricating organic light emitting diodes (OLEDs) [2–5]. Among them, metal 8-hydroxyquinoline (Mqn) chelates, especially for tris(8-hydroxyquinoline)aluminum (Alq3), and bis(8-hydroxyquinoline) znic(II) (Znq2) have been extensively investigated for their high stabilities, good emissions, and electron-transporting properties [6–8]. Compared with low-weight 8-hydroxyquinoline (Mqn) chelate, the polymers containing Mqn pendant groups combine the fluorescent property of Mqn and the processability of the polymer [6, 7, 9]. Up to now, two types of Mqn-containing polymers (main-chain type and side-chain type) have been reported. Yamamoto and Yamaquchi reported the synthesis of poly(quinolinol) [10] and poly(aryleneethynylene) [11] containing 8-quinolinol moieties. On the other hand, various side-chain type polymers including poly(arylene ether) [12], copolymers of 7-allyl-, or 7-(2-methylvinyl)-functionalized derivatives of 8-hydroquinoline with styrene [13], functionalized polystyrene [14], and copolymers of methacrylates having 8-hydroxyquinoline moieties were also successfully prepared [15]. Furthermore, Mqn-containing polymers were obtained by the reaction of the above polymers with metal compounds in the presence of monomeric 8-hydroxyquinoline. Meyers and Weck, reported the synthesis of an Alq3-functionalized polymer
Progress of Application Researches of Porous Fiber Metals
Zhengping Xi,Jilei Zhu,Huiping Tang,Qingbo Ao,Hao Zhi,Jianyong Wang,Cheng Li
Materials , 2011, DOI: 10.3390/ma4040816
Abstract: Metal fiber porous materials with intrinsic properties of metal and functional properties of porous materials have received a great deal of attention in the fundamental research and industry applications. With developments of the preparation technologies and industrial requirements, porous fiber metals with excellent properties are developed and applied in many industry areas, e.g., sound absorption, heat transfer, energy absorption and lightweight structures. The applied research progress of the metal fiber porous materials in such application areas based on the recent work in our group was reviewed in this paper.
DEGRADATION CONTROL AND PROPERTIES OPTIMIZATION OF in situ COMPATIBILIZED PS/POE BLENDS BY FRIEDEL-CRAFTS ALKYLATION REACTION
F-C烷基化反应原位增容PS/POE共混物中降解的抑制和增容效果的优化

GUO Zhenghong,FANG Zhengping,CHENG Jie,
郭正虹
,方征平,程捷

高分子学报 , 2009,
Abstract: in situ Compatibilization by Friedel-Crafts alkylation reaction has the commercial potential in the recycling of commingled post-consumed polymers containing polystyrene (PS) and polyolefin.The most important problem in the approach of in situ compatibilization of PS/POE (polyolefin elastomer) blends is to increase the efficiency of grafting and limit the degradation of the blending components.In order to increase the efficiency of grafting,the styrene (St) monomers were added into the in situ compatibilized PS/polyolefin elastomer (POE) blends.The graft degree of PS/POE/St/AlCl3 (80/20/n/0.8,wt%) increased from 8.6% to 14.0% with the St content increased from 0 to 0.6%,indicating that the addition of St could accelerate the Friedel-Crafts alkylation reaction.The St/AlCl3 catalyst system initiated more PS-graft-POE copolymers than the single AlCl3 catalyst.Because those PS-graft-POE copolymers acted as the compatibilizers between the interface of PS and POE,the mechanical properties of PS/POE blends were greatly improved.For example,the Charpy impact strength increased from 8.5 kJ/m2 to 9.9 kJ/m2 and the elongation at break increased from 22% to 29% when 0.6% St was added to PS/POE/AlCl3 (80/20/0.8,wt%) blend.Besides,the two-step extrusion procedure gave better mechanical properties of PS/POE blends,which were the results of a limitation of degradation of blending components when the master batch product and virgin polymers were extruded in the second extrusion step.
Convergence or Divergence? Chinese Novice EFL Teachers’ Beliefs about Postmethod and Teaching Practices
Zhengping Zeng
English Language Teaching , 2012, DOI: 10.5539/elt.v5n10p64
Abstract: Recently, there have been numerous researches focusing on postmethod. Generally, the researches can be divided into three perspectives: a new look at method, theoretical exploration of postmethod, implication for teacher education. Obviously, language researchers tend to focus on the theoretical review on postmethod ignoring the actual use of postmethod in practice. The study was conducted to explore Chinese novice EFL teachers’ conceptions and implement of postmethod. The data were collected through lesson observations and interviews. The results reveal that the novice teachers lack the knowledge of postmethod, that they are greatly influenced by examination-oriented education, and that there is a discrepancy between teaching behaviors and teacher beliefs.
SYNTHESIS AND CHARACTERIZATION OF BIODEGRADABLE POLY(5-HYDROXYLEVULINIC ACID-co-L-LACTIC ACID)
生物可降解聚(5-羟基乙酰丙酸-co-L-乳酸)的合成与表征

ZHANG Yan,GUO Zhenghong,CHENG Jie,FANG Zhengping,
张艳
,郭正虹,程捷,方征平

高分子学报 , 2009,
Abstract: Synthesis of biobased and biodegradable polymers from renewable biomass has attracted much attention in recent years.Levulinic acid has been deemed as a platform chemical from non-food stuff biomass,and some of its derivatives are starting materials for new polymers.In this paper,poly(5-hydroxylevulinic acid-co-L-lactic acid)(PHLL) was synthesized via melt copolycondensation of 5-hydroxylevulinic acid(5-HLA) and L-lactic acid(LLA) and characterized with GPC,X-ray,~1H-NMR,FTIR and DSC.The results showed that...
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