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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

Dynamic Pendulum Effect of an Exceptionally Flexible Pillared-Layer Metal-Organic Framework

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Chinese Journal of Chemistry 2021年第10期39卷 2718-2724页

作者： hao-long zhou Jie Bai Xiao-Yun Tian Zong-Wen Mo Xiao-Ming Chen MOE Key Laboratory of Bioinorganic and Synthetic Chemistry School of ChemistrySun Yat-Sen UniversityGuangzhouGuangdong510275 China Department of Chemistry ond Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province Shantou UniversityShantouGuangdong 515063China

Main observation and conclusion Magnifying the controllable directional motions of molecular machines to the macroscopic levels is a significant topic for *** metal–organic frameworks with long-range order and responsive structural transformation under external stimuli may be an appropriate platform for achieving the *** taking advantage of the single-crystal to single-crystal manner of soft porous crystals,we utilize single-crystal X-ray diffraction to directly observe the dynamic structural inversion of a new three-fold interpenetrated pillared-layer metal-organic framework[Co(edba)(bpy)](MCF-83,H2edba=4,4’-(ethyne-1,2-diyl)dibenzoic acid,bpy=4,4’-bipyridine).More interestingly,the dynamic inversions of the pillars and layers are selectively guest-controllable and independent,allowing precise control of the directional shape changes,which is the key of constructing intelligent materials to accomplish a complex *** mechanism is further studied by combining the X-ray diffraction analyses,sorption measurements and molecular simulations.

关键词： Porous coordination polymers Metal-organic frameworks Structural transformation X-ray diffraction Adsorption

Glutamicibacter nicotianae AT6:A new strain for the efficient biodegradation of tilmicosin

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Journal of Environmental Sciences 2024年第8期142卷 182-192页

作者： Huijuan Li hao zhou Liling Fan long Meng Yanyun Zhao Lanmei Zhao Bo Wang College of Chemical and Biological Engineering Shandong University of Science and TechnologyQingdao 266590China College of Chemistry and Chemical Engineering Heze UniversityHeze 274015China College of Safety and Environmental Engineering Shandong University of Science and TechnologyQingdao 266590China

The degradation of tilmicosin(TLM),a semi-synthetic 16-membered macrolide antibiotic,has been receiving increasing ***,there are three tilmicosin degradation methods,and among them microbial degradation is considered the best due to its high efficiency,eco-friendliness,and low ***,we found a new strain,Glutamicibacter nicotianae ***6,capable of degrading high-concentration TLM at 100 mg/L with a 97%removal *** role of tryptone was as well investigated,and the results revealed that the loading of tryptone had a significant influence on TLM *** toxicity assessment indicated that strain AT6 could efficiently convert TLM into less-toxic *** on the identified intermediates,the degradation of TLM by AT6 processing through two distinct pathways was then proposed.

关键词： Tilmicosin Glutamicibacter nicotianae Biodegradation Degradation pathway Pharmaceutical wastewater

Flexibility of Metal-Organic Framework Tunable by Crystal Size at the Micrometer to Submillimeter Scale for Efficient Xylene Isomer Separation

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Research 2019年第1期2019卷 433-441页

作者： Xiao Yang hao-long zhou Chun-Ting He Zong-Wen Mo Jia-Wen Ye Xiao-Ming Chen Jie-Peng Zhang MOE Key Laboratory of Bioinorganic and Synthetic Chemistry School of ChemistrySun Yat-Sen UniversityGuangzhou 510275China

Understanding,controlling,and utilizing the flexibility of adsorbents are of great importance and *** with conventional solid materials,downsizing to the nanoscale is emerging as a possible strategy for controlling the flexibility of porous coordination polymers(or metal-organic frameworks).We report a unique flexibility controllable by crystal size at the micrometer to submillimeter *** removal transforms[Cu_(2)(pypz)_(2)]·0.5p-xylene(MAF-36,Hpypz=4-(1H-pyrazol-4-yl)pyridine)with one-dimensional channels toα-[Cu_(2)(pypz)_(2)]with discrete small cavities,and further heating gives a nonporous isomerβ-[Cu_(2)(pypz)_(2)].Both isomers can adsorb p-xylene to give[Cu_(2)(pypz)_(2)]·0.5p-xylene,meaning the coexistence of guest-driven flexibility and shape-memory *** phase transition temperature fromα-[Cu_(2)(pypz)_(2)]toβ-[Cu_(2)(pypz)_(2)]decreased from~270℃ to~150℃ by increasing the crystal size from the micrometer to the submillimeter scale,ca.2-3 orders larger than those of other size-dependent ***-crystal X-ray diffraction showed coordination bond reconstitution and chirality inversion mechanisms for the phase transition,which provides a sufficiently high energy barrier to stabilize the metastable phase without the need of downsizing to the *** virtue of the crystalline molecular imprinting and gate-opening effects,α-[Cu_(2)(pypz)_(2)]andβ-[Cu_(2)(pypz)_(2)]show unprecedentedly high p-xylene selectivities of 16 and 51,respectively,as well as ultrafast adsorption kinetics(<2 minutes),for xylene isomers.

关键词： isomers coordination adsorbent

Effect of CO_(2) Opposing Multiple Jets on Thermoacoustic Instability and NO_(x) Emissions in a Lean-Premixed Model Combustor

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Journal of Thermal Science 2024年第1期33卷 207-221页

作者： zhou hao HU Liubin Institute for Thermal Power Engineering State Key Laboratory of Clean Energy UtilizationZhejiang UniversityHangzhou 310027China

This paper experimentally studied the effect of CO_(2) opposing multiple jets on the thermoacoustic instability and NO_(x) emissions in a lean-premixed model *** feasibility was verified from three variables:the CO_(2) jet flow rate,hole numbers,and hole diameters of the *** indicate that the control effect of thermoacoustic instability and NO_x emissions show a reverse trend with the increase of open area ratio on the whole,and the optimal jet flow rate range is 1-4 L/min with CO_(2) opposing multiple *** this flow rate range,the amplitude and frequency of the dynamic pressure and heat release signals CH~* basically decrease as the CO_(2) flow rate increases,which avoids high-frequency and high-amplitude thermoacoustic *** amplitude-damped ratio of dynamic pressure and CH*can reach as high as 98.75% and 93.64% with an optimal open area ratio of 3.72%.NO_(x) emissions also decrease as the jet flow rate increases,and the maximum suppression ratio can reach 68.14%.Besides,the flame shape changes from a steep inverted "V" to a more flat "M",and the flame length will become shorter with CO_(2) opposing multiple *** research achieved the synchronous control of thermoacoustic instability and NO_(x) emissions,which could be a design reference for constructing a safer and cleaner combustor.

关键词： thermoacoustic instability lean-premixed model combustor CO_(2)opposing multiple jets open area ratio NO_(x)emissions

Enhancing SAEAs with unevaluated solutions:a case study of relation model for expensive optimization

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Science China(Information Sciences) 2024年第2期67卷 41-58页

作者： hao hao Xiaoqun ZHANG Aimin zhou Institute of Natural Sciences Shanghai Jiao Tong University Shanghai Frontiers Science Center of Molecule Intelligent Syntheses School of Computer Science and Technology East China Normal University

Surrogate-assisted evolutionary algorithms(SAEAs) hold significant importance in resolving expensive optimization problems. Extensive efforts have been devoted to improving the efficiency of SAEAs through the development of proficient model-assisted solution selection methods, which, however, first requires generating high-quality solutions. The fundamental paradigm of evaluating a limited number of solutions in each generation within SAEAs reduces the variance of adjacent populations, thereby affecting the quality of offspring solutions. This is a frequently encountered issue yet receives little attention. To address the issue, this paper presents a framework using unevaluated solutions to enhance the efficiency of *** surrogate model is employed to identify high-quality solutions for the direct generation of new solutions without evaluation. To ensure dependable selection, we have introduced two tailored relation models to select the optimal solution and the unevaluated population. A comprehensive experimental analysis is performed on two test suites, which showcases the superiority of the relation model over regression and classification models in the solution selection phase. Furthermore, the surrogate-selected unevaluated solutions with high potential have been shown to enhance the efficiency of the algorithm significantly.

关键词： expensive optimization unevaluated solutions relation model surrogate-assisted evolutionary algorithm

Graded Heterojunction Improves Wide-Bandgap Perovskite for Highly Efficient 4-Terminal Perovskite/Silicon Tandem Solar Cells

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Research 2024年第2期2023卷 181-190页

作者： Wenming Chai Lindong Li Weidong Zhu Dazheng Chen long zhou He Xi Jincheng Zhang Chunfu Zhang Yue hao State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology&Shaanxi Joint Key Laboratory of Graphene School of MicroelectronicsXidian UniversityXi'anShaanxi 710071China Xi'an Baoxin Solar Technology Co. Ltd.Xi'an710071China

Wide-bandgap(WBG)perovskite solar cells(PSCs)are essential for highly efficient and stable silicon/perovskite tandem solar *** this study,we adopted a synthetic strategy with lead thiocyanate(Pb(SCN)_(2))additive and methylammonium chloride(MACl)posttreatment to enhance the crystallinity and improve the interface of WBG perovskite films with a bandgap of 1.68 *** excessive PbI_(2)was formed at grain boundaries and converted into MAPbI_(3-x)Cl_(x)perovskites,which are utilized to form the graded heterojunction(GHJ)and compressive *** is beneficial for passivating nonradiative recombination defects,suppressing halide phase segregation,and facilitating carrier ***,the device with GHJ delivered a champion efficiency of 20.30%and superior stability in ambient air and under 85℃.Finally,we achieved a recorded efficiency of 30.91%for 4-terminal WBG perovskite/TOPCon tandem silicon solar *** findings demonstrate a promising approach for fabricating efficient and stable WBG PSCs through the formation of GHJ.

关键词： perovskite Graded Highly

Copper-catalyzed enantioselective desymmetrizing C(sp^(2))-H functionalization of azide-ynamides via α-imino copper carbenes

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Science China Chemistry 2024年第9期67卷 2982-2988页

作者： En-He Huang Li-Gao Liu You-Wei Yin hao-Xuan Dong Ji-Jia zhou Xin Lu Bo zhou long-Wu Ye Key Laboratory for Chemical Biology of Fujian Province and State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

α-Imino metal carbenes are versatile intermediates in organic synthesis,and have broad applications in the assembly of divergent ***,the catalytic enantioselective desymmetrization based onα-imino metal carbenes has not been developed to ***,we disclose an enantioselective desymmetrizing C(sp^(2))-H functionalization of azide-ynamides viaα-imino copper carbenes,leading to the efficient assembly of divergent chiral indoloazepines in generally moderate to excellent yields with high ***,this reaction represents the first enantioselective desymmetrization based onα-imino metal *** synthetic transformations and biological tests show the potential utility of this ***,computational studies are employed to elucidate the reaction mechanism and the origin of enantioselectivity.

关键词： enantioselective desymmetrization metal carbenes copper catalysis nitrene transfer alkynes

MLDA:a multi-level k-degree anonymity scheme on directed social network graphs

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Frontiers of Computer Science 2024年第2期18卷 199-215页

作者： Yuanjing hao long LI Liang CHANG Tianlong GU Guangxi Key Laboratory of Trusted Software Guilin University of Electronic TechnologyGuilin 541004China Engineering Research Center of Trustworthy AI(Ministry of Education) Jinan UniversityGuangzhou 510632China

With the emergence of network-centric data,social network graph publishing is conducive to data analysts to mine the value of social networks,analyze the social behavior of individuals or groups,implement personalized recommendations,and so ***,published social network graphs are often subject to re-identification attacks from adversaries,which results in the leakage of users’***-anonymity technology is widely used in the field of graph publishing,which is quite effective to resist re-identification ***,the current researches still exist some issues to be solved:the protection of directed graphs is less concerned than that of undirected graphs;the protection of graph structure is often ignored while achieving the protection of nodes’identities;the same protection is performed for different users,which doesn’t meet the different privacy requirements of ***,to address the above issues,a multi-level-degree anonymity(MLDA)scheme on directed social network graphs is proposed in this ***,node sets with different importance are divided by the firefly algorithm and constrained connectedness upper approximation,and they are performed different-degree anonymity protection to meet the different privacy requirements of ***,a new graph anonymity method is proposed,which achieves the addition and removal of edges with the help of fake *** addition,to improve the utility of the anonymized graph,a new edge cost criterion is proposed,which is used to select the most appropriate edge to be ***,to protect the community structure of the original graph as much as possible,fake nodes contained in a same community are merged prior to fake nodes contained in different *** results on real datasets show that the newly proposed MLDA scheme is effective to balance the privacy and utility of the anonymized graph.

关键词： directed social network graph graph publishing k-degree anonymity community structure graph utility