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Expansion series of the pairwise velocity generating function and its implications on redshift space distortion modeling

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Research in Astronomy and Astrophysics 2021年第7期21卷 209-222页

作者： Jun-De Chen peng-jie zhang Yi Zheng Department of Astronomy Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai 200240China Tsung-Dao Lee Institute Shanghai 200240China School of Physics and Astronomy Sun Yat-sen UniversityTangjia 519082China

The pairwise velocity generating function G has a deep connection with both the pairwise velocity probability distribution function and modeling of redshift space distortion(RSD).Its implementation into RSD modeling is often faciliated by expansion into a series of pairwise velocity moments(v^(n)_(12))-Motivated by the logrithmic transformation of the cosmic density field,we investigate an alternative expansion into series of pairwise velocity cumulants(v^(n)_(12))*** numerically evaluate the convergence rate of the two expansions,with three 30723 particle simulations of the CosmicGrowth N-body simulation series.(1)We find that the cumulant expansion performs significantly better,for all the halo samples and redshifts investigated.(2)For modeling RSD at k||

关键词： cosmology dark energy dark matter large-scale structure of universe

Performance analysis of optical multicast in a new switching structure

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The Journal of China Universities of Posts and Telecommunications 2007年第3期14卷 43-47页

作者： JIA peng zhang jie GU Wan-yi Key Laboratory of Optical Communication and Lightwave Technologies Ministry of Education Beijing University of Posts and TelecommunicationsBeijing 100876 China

The emergence of new services demands multicast function in optical network. Because of the high cost and complex architecture of multicast capable （MC） node, splitter- sharing switch structure is introduced in which the light splitters are shared by all input signals. To accommodate to this situation, by extending resource ReSerVation protocol-traffic engineering （RSVP-TE） and open shortest path first-traffic engineering （OSPF-TE）, a new optical multicast mechanism is provided and the signaling flow and its finite state machine model are given. At the same time, a multicast routing algorithm in splitter-sharing optical network and a changing link weight policy to balance network traffic are proposed. Simulations in NSFNET show no matter with or without wavelength converters, when the number of splitters is 25% of that demanded by traditional MC nodes, the multicast performance has been close to the ideal circumstance. Wavelength converters and changing link weight help much in improving the traffic performance when the number of splitters is adequate.

关键词： splitter-sharing optical multicast optical network wavelength converter

Optimizing luminescence sensitivity and moisture stability of porous coordination frameworks by varying ligand side groups

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Science China Chemistry 2019年第3期62卷 341-346页

作者： Jia-Wen Ye Xu-Yu Li Hao-Long Zhou jie-peng zhang MOE Key Laboratory of Bioinorganic and Synthetic Chemistry School of Chemistry Sun Yat-Sen University

Hydrophobic ethyl, butyl or hexyl groups were introduced into the dicarboxylate ligand in the fluorescent porous coordination framework [Zn_2(fda)_2(bpy)](LMOF-202, H_2fda=9H-fluorene-2,7-dicarboxylic acid, bpy=4,4′-bipyridine) for improving water stability and tuning oxygen sensitivity. The long hexyl groups gave satisfactory water stability but its oxygen sensitivity is low(70.8% fluorescence quenched at 1 bar O_2(1 bar=105 Pa)). In contrast, the shorter side groups gave high oxygen sensitivity(93.9% fluorescence quenched at 1 bar O_2) and low water stability. The derivation of the Stern-Volmer curves of the O_2 luminescence quenching data from the linear form can be used for detecting trace impurities in the luminescent framework, being much more sensitive than conventional methods such as powder X-ray diffraction. Mixing the ethyl and hexyl groups in the solid-solution manner brought high oxygen sensitivity(96.4% fluorescence quenched at 1 bar O_2) and high water stability simultaneously in the same coordination framework.

关键词： metal-organic framework water stability oxygen fluorescence sensor

A partially fluorinated ligand for two super-hydrophobic porous coordination polymers with classic structures and increased porosities

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National Science Review 2021年第3期8卷 99-107页

作者： Chao Wang Dong-Dong Zhou You-Wei Gan Xue-Wen zhang Zi-Ming Ye jie-peng zhang MOE Key Laboratory of Bioinorganic and Synthetic Chemistry School of ChemistrySun Yat-Sen University

3-Ethyl-5-trifluoromethyl-1,2,4-triazole is synthesized by a one-pot *** this asymmetric triazole ligand bearing one trifluoromethyl and one ethyl as side groups,we construct two new porous coordination polymers,MAF-9 and MAF-2 F,being isostructural with the classic hydrophobic and flexible materials,FMOF-1 and MAF-2,based on symmetric triazole ligands bearing two trifluoromethyl groups or two ethyl groups,***-9 and MAF-2 F can adsorb large amounts of organic solvents but completely exclude water,showing superhydrophobicity with water contact angles of 1520 in between those of FMOF-1 and ***-9 exhibits very large N2-induced breathing and colossal positive and negative thermal expansions like FMOF-1,but the lower molecular weight and smaller volume of MAF-9 give 16%and 4% higher gravimetric and volumetric N2uptakes,*** contrast,MAF-2 F is quite rigid and does not show the inversed temperature-dependent N2adsorption and large guest-induced expansion like ***,despite the higher molecular weight and larger volume,MAF-2 F possesses 6% and 25%higher gravimetric and volumetric CO2uptakes,*** results can be explained by the different pore sizes and side group arrangements in the two classic framework prototypes,which demonstrate the delicate roles of ligand side groups in controlling porosity,surface characteristic and flexibility.

关键词： porous coordination polymers metal-organic frameworks super-hydrophobicity flexibility

Weak lensing magnification reconstruction with the modified internal linear combination method

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Research in Astronomy and Astrophysics 2021年第10期21卷 51-60页

作者： Shu-Tong Hou Yu Yu peng-jie zhang Department of Astronomy School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory for Particle Physics and Cosmology Shanghai Jiao Tong UniversityShanghai 200240China Tsung-Dao Lee Institute Shanghai 200240China

Measuring weak lensing cosmic magnification signal is very challenging due to the overwhelming intrinsic clustering in the observed galaxy *** this paper,we modify the Internal Linear Combination(ILC)method to reconstruct the lensing signal with an extra constraint to suppress the intrinsic *** quantify the performance,we construct a realistic galaxy catalogue for the LSST-like photometric survey,covering 20000 deg^(2) with mean source redshift at z_(s)~*** find that the reconstruction performance depends on the width of the photo-z bin we *** to the correlation between the lensing signal and the source galaxy distribution,the derived signal has smaller systematic bias but larger statistical uncertainty for a narrower photo-z *** conclude that the lensing signal reconstruction with the Modified ILC method is unbiased with a statistical uncertainty <5% for bin width Δz^(P)=0.2.

关键词： cosmology:observations large-scale structure of universe weak lensing

A topology approach to overcome the pore size/volume trade-offs for autonomous indoor humidity control

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Science China Chemistry 2024年第9期67卷 2968-2974页

作者： Zhi-Shuo Wang Xue-Wen zhang Kai Zheng Xiao-Xian Chen Dong-Dong Zhou jie-peng zhang MOE Key Laboratory of Bioinorganic and Synthetic Chemistry GBRCE for Functional Molecular EngineeringSchool of ChemistryIGCMESun Yat-Sen UniversityGuangzhou 510275China Chemistry and Chemical Engineering Guangdong Laboratory Shantou 515021China

Autonomous indoor humidity control is gaining more and more attention but is limited by the trade-offs among pore volume,pore size and water stability of water *** solve this problem by using a unique coordination network topology combined with hydrolytically stable M(Ⅲ)carboxylate *** extending the ligand length from 9.0 to 11.2 and 13.7?,the pore volume significantly increases from 0.99 to 1.40 and 1.78 cm^(3)g^(-1),which proportionally increases the saturated water adsorption ***,the pore size slightly increases from 10.4 to 11.0 and 13.5A,which restricts the isotherm inflection pressure and hysteresis width to meet the requirement of indoor humidity *** single-crystals suitable for Xray diffraction studies were obtained by using Fe(Ⅲ)salts,while isostructural frameworks with sufficiently high water stabilities were synthesized by using Cr(Ⅲ)salts,which offer record working capacity of 0.90 and 1.10 g g^(-1)for indoor humidity control.

关键词： metal-organic frameworks water adsorption indoor humidity control water stability pore engineering

Controlling flexibility of metal–organic frameworks

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National Science Review 2018年第6期5卷 907-919页

作者： jie-peng zhang Hao-Long Zhou Dong-Dong Zhou Pei-Qin Liao Xiao-Ming Chen MOE Key Laboratory of Bioinorganic and Synthetic Chemistry School of ChemistrySun Yat-Sen University Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province Shantou University

Framework flexibility is one of the most important characteristics of metal–organic frameworks(MOFs),which is not only interesting, but also useful for a variety of applications. Designing, tailoring or controlling framework flexibility of MOFs is much more difficult than for static structural features such as the framework topology and pore size/shape. Nevertheless, with in-depth understanding of the relationship between framework flexibility and the host framework structure, guest loading and other aspects such as the crystal size/morphology and external physical environment, some strategies have been developed for controlling the flexibility of MOFs and the corresponding properties, which are summarized and discussed in this review.

关键词： porous coordination polymers metal–organic frameworks flexibility dynamism adsorption structural transformation

Effects of solid-solution temperature on microstructure and mechanical properties of a novel 2000MPa grade ultra-high-strength steel

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Journal of Iron and Steel Research International 2020年第6期27卷 710-718页

作者： Chun-xu Wang Yuan-hang Gao Yong Li Shun Han Shao-zun Liu peng-jie zhang Central Iron and Steel Research Institute Beijing100081China

A novel 2000 MPa grade ultra-high-strength steel AIR0509 with high fracture toughness and low cost has recently been developed. The effects of solid-solution temperature on the microstructure and mechanical properties of this steel were inves-tigated. The increase in solid-solution temperature first increased and then decreased the values of ultimate strength (UTS) and Charpy U-notch (CUN) energy. The increase in the UTS and CUN values was caused by the dissolution of the primary carbides M6C and MC, while the decrease in both strength and toughness was due to the increase in the prior austenite grain size. Samples that were solid-solution treated at 1000℃ exhibited an optimal combination of strength and toughness with a UTS of 2020MPa, yield strength of 1780MPa, and CUN energy of 68J, as well as a correlative fracture toughness KIC value of about 105MPam1/2.

关键词： Ultra-high-strength steel Solid-solution treatment Carbide Mechanical property Microstructure

Multistep evolution from a metal–organic framework to ultrathin nanosheets

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Science Bulletin 2019年第14期64卷 964-967页

作者： Yun Li Jin Huang Zong-Wen Mo Xue-Wen zhang Xiao-Ning Cheng Li Gong Dong-Dong Zhou jie-peng zhang MOE Key Laboratory of Bioinorganic and Synthetic Chemistry School of Chemistry Sun Yat-Sen University Guangzhou 510275 China Instrumental Analysis and Research Center Sun Yat-Sen University Guangzhou 510275 China

Two-dimensional (2D) materials and ultrathin nanosheets have attracted tremendous research interests [1-4]. Exfoliation of porous coordination polymers (PCPs) or metal-organic frameworks (MOFs) with 2D coordination structures is emerging as a viable strategy for preparation of new types of 2D materials [5-8]. The relatively weak bonding within and strong interactions between 2D coordination networks are the main problems for successful exfoliation [9]. Pretreatments of the layered MOFs to expand the interlayer distances can be helpful [10-12]. Capturing the exfoliation intermediates and visualizing their structures are valuable for understanding the exfoliation mechanism and confirming the structures of the final 2D materials [11,12].

关键词： Two-dimensional (2D) porous coordination polymers (PCPs) metal-organic frameworks (MOFs)