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Experiment on acoustic emission response and damage evolution characteristics of polymer-modified cemented paste backfill under uniaxial compression

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International Journal of Minerals,Metallurgy and Materials 2023年第8期30卷 1502-1514页

作者： Shenyang Ouyang Yanli Huang nan zhou Ming Li Xiaotong Li Junmeng Li Fei Ke Yahui Liu State Key Laboratory of Coal Resources and Safe Mining School of MinesChina University of Mining and TechnologyXuzhou 221116China Xinjiang Institute of Engineering Urumqi 830000China Henan Energy Chemical Group Co. Ltd.Zhengzhou 450000China

The mechanical properties of cemented paste backfill(CPB)determine its control effect on the goaf *** this study,the mechanical strength of polymer-modified cemented paste backfill(PCPB)samples was tested by uniaxial compression tests,and the failure characteristics of PCPB under the compression were ***,acoustic emission(AE)technology was used to monitor and record the cracking process of the PCPB sample with a curing age of 28 d,and two AE indexes(rise angle and average frequency)were used to classify the failure modes of samples under different loading *** results show that waterborne epoxy resin can significantly enhance the mechanical strength of PCPB samples(when the mass ratio of polymer to powder material is 0.30,the strength of PCPB samples with a curing age of 28 d is increased by 102.6%);with the increase of polymer content,the mechanical strength of PCPB samples is improved significantly in the early and middle period of *** uniaxial load,the macro cracks of PCPB samples are mostly generated along the axial direction,the main crack runs through the sample,and a large number of small cracks are distributed around the main *** AE response of PCPB samples during the whole loading process can be divided into four periods:quiet period,slow growth period,rapid growth period,and remission period,corresponding to the micro-pore compaction stage,elastic deformation stage,plastic deformation stage,and failure instability stage of the stress-strain *** AE events are mainly concentrated in the plastic deformation stage;both shear failure and tensile failure occur in the above four stages,while tensile failure is dominant for PCPB *** study provides a reference for the safety of coal pillar recovery in pillar goaf.

关键词： polymer cemented paste backfill mechanical strength acoustic emission

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Existence and uniqueness of solutions for a hierarchical system of two age-structured populations

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Frontiers of Mathematics in China 2023年第1期18卷 51-62页

作者： Zerong HE nan zhou Mengjie HAN Institute of Operational Research and Cybernetics Hangzhou Dianzi UniversityHangzhou 310018China

We propose a class of new hierarchical model for the evolution of two interacting age-structured populations,which is a system of integro-partial differential equations with global feedback boundary conditions and may describe the interactions such as competition,cooperation and predator-prey *** upon a group of natural conditions,the existence and uniqueness of solutions on infinite time interval are proved by means of fixed point and extension principle,and the continuous dependence of the solution on the initial age distribution is *** results lay a sound basis for the investigation of stability,controllability and variable optimal control problems.

关键词： Hierarchy of ages population system integro-partial differential equations existence and uniqueness fixed points

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Release behavior of soluble salts in MSWI bottom ash used as road basement materials under continuous rainfall conditions

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Waste Disposal and Sustainable Energy 2023年第4期5卷 525-534页

作者： Lingqin Zhao Dongming Zhang Yanjun Hu Qianqian Guo Long Jiao nan zhou Francesco Di Maio Institute of Thermal and Power Engineering Zhejiang University of TechnologyLiuhe Road 28#310023HangzhouChina Zhejiang Zheneng Xingyuan Energy Saving Technology Co.Ltd Gongshu District310011HangzhouChina Delft University of Technology P.O.Box 50482628DelftThe Netherlands

The bottom ash is increasingly used as a substitute aggregate material in road construction in China,and road salting is the major salt source in *** rainfall releases soluble salts from the bottom ash subgrade into the surrounding soil and groundwater,resulting in potential *** methods were employed to simulate and collect runoff water during rainfall events,including batch leaching test,dynamic leaching test and constant head test,to assess environmental impact of bottom ash as road basement materials under continuous rainfall *** study simulated the seepage of bottom ash backfill roads under different rainfall intensities,rainfall times,and rainfall pH values.A comprehensive sampling and laboratory testing program was undertaken to characterize the environmental impact of soluble salts from bottom *** obtained results reveal that the leaching concentrations of Cl^(−)and SO_(4)^(2−)exceed the limit specified in the class V standard of surface water,which are 2.06–2.17 times and 1.08–1.25 times,*** examining the long-term environmental influence under the condition of continuous rainfall,the leaching of Cl^(−)mainly occurs in the early leaching stage,and the maximum leaching concentration reaches 19,700 mg/*** release concentration of Cl^(−)begins to be lower than the class V standard of surface water when continuous rainfall approaches the total rainfall for 13 *** cumulative release of Cl^(−)in the bottom ash is 2.8–5.4 mg/*** rainfall intensity and rain pH affect the release of Cl^(−).The obtained results derived from the constant head tests indicate that stagnant water caused by rainfall deteriorates the release of soluble salt into the groundwater in only 1 day,especially at the early stage of 12 *** work provides some basic information about how to minimize damage to the surrounding environment caused by the leaching of salt in bottom ash.

关键词： Municipal solid waste Incineration bottom ash Salts Leaching Continuous rainfall

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Stereochemistry and solid-state circular dichroism spectroscopy of eight-coordinate chiral lanthanide complexes

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Science China Chemistry 2009年第11期52卷 1851-1857页

作者： zhou nan WAN ShiGang ZHAO Jian LIN YiJi XUAN WeiMin FANG XueMing ZHANG Hui State Key Laboratory of Physical Chemistry of Solid Surface and Department of Chemistry College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China

Eight-coordinate chiral lanthanide complexes [Eu(dbm)3LRR](1),[Eu(dbm)3LSS](2) and [Tb(dbm)3LRR](3)(LRR/LSS =(-)-/(+)-4,5-pineno-2,2'-bipyridine,Hdbm = dibenzoylmethane) were synthesized stereoselectively,which were characterized by UV-vis,CD spectra and X-ray single-crystal *** mirrorimage structure features of complexes 1 and 2 were obtained by combination of the solid-state CD spectra and the crystal structure *** further comparison with the solid-state CD spectra of six-coordinate and seven-coordinate metal complexes containing β-diketone ligands,the CD spectraabsolute configuration correlation rule for the eight-coordinate β-diketonate lanthanide complexes was proposed through the exciton chirality method for the first *** △ or Λ absolute configurations of complexes 1―3 with the distorted square antiprism geometry were confirmed by the X-ray single-crystal analysis.

关键词： eight-coordinate lanthanide complex β-diketone chiral bipyridine crystal structure solid-state CD spectroscopy absolute configuration

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An improved and practical route for the synthesis of enzalutamide and potential impurities study

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Chinese Chemical Letters 2017年第2期28卷 426-430页

作者： Ai-nan zhou Bonan Li Lejun Ruan Yeting Wang Gengli Duan Jianqi Li Novel Technology Center of Pharmaceutical Chemistry Shanghai Institute of Pharmaceutical Industry School of Pharmacy Fudan University

An improved and practical synthesis of enzalutamide was accomplished in five *** from 4-bromo-2-fluoro-benzonic acid,a methyl esterification,Ullmann ligation,methyl esterification,ring closing reaction and final methyl amidation provided the target in 35% total yield with 99.8% *** identified impurities were also *** efficient and economical procedure avoids the use of highly toxic reagents and multiple recrystallization operations,which is suitable for further industrialization.

关键词： Enzalutamide New route High purity Impurity

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New concurrent digital signature scheme based on the computational Diffie-Hellman problem

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The Journal of China Universities of Posts and Telecommunications 2010年第6期17卷 89-94,100页

作者： QIN Wen,zhou nan-run Department of Electronic Information Engineering,nanchang University,nanchang 330031,China [a] Department of Electronic Information Engineering Nanchang University Nanchang 330031 China

Based on strong designated verifiers signatures,a new fair concurrent signature scheme is proposed. Compared with the previous concurrent signature schemes,even if a keystone must be chosen by the initial signer,the matching signer will easily get the keystone through an extraction algorithm. Due to the property of strong designate verifying,the initial signer couldn＇t make use of the keystone prepared carefully to deceive the matching signer. Then the matching signer is able to participate actively the signature scheme. Besides,there aren＇t bilinear operations in the keystone algorithm to deliver the keystone efficiently. Therefore the efficiency of our signature scheme is also improved.

关键词： designated verifiers signature fairness concurrent signature information security

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Strata movement controlling effect of waste and fly ash backfillings in fully mechanized coal mining with backfilling face

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Mining Science and Technology 2011年第5期21卷 721-726页

作者： Zhang Jixiong Zhang Qiang Huang Yanli Liu Jinwei zhou nan Zan Dongfeng School of Mines China University of Mining ＆ Technology Xuzhou 221116 China State Key Laboratory of Coal Resources and Mine Safety Xuzhou 221008 China Huayuan Mine fining Sources of Energy Development Group Co. Ltd. fining 272100 China

A fully mechanized coal mining with backfilling (FMCMB) provides advantages of safety and efficiency for coal mining under buildings, railways, and water bodies. According to the field geological conditions, we analyzed the controlling effect of strata movement by the waste and fly ash backfilling in FMCMB face. Based on the key strata theory, we established the equivalent mining thickness model, and analyzed the action of the bulk factor of backfilling body to the equivalent mining thickness. In addition, we numerically simulated the controlling function of the strata movement by backfilling bodies with differ- ent strength. And the numerical simulation result show that the deformation of stratum and the subsi- dence of surface can be controlled by FMCMB. The result provides references to the effective execution of fully mechanized coal mining with solid waste backfilling in goaf.

关键词： Waste and tly ashBackfilling body (BB)FMCMBStrata movementEquivalent mining thicknessNumerical simulation

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Combining of chemotherapy with targeted therapy for advanced biliary tract cancer:A systematic review and meta-analysis

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World Journal of Gastrointestinal Oncology 2022年第10期14卷 2061-2076页

作者： Xue-Song Bai Sheng-nan zhou Yi-Qun Jin Xiao-Dong He Department of General Surgery Peking Union Medical College HospitalChina Academy of Medical Science&Peking Union Medical CollegeBeijing 100730China Affiliated Hangzhou First People’s Hospital Zhejiang University School of MedicineHangzhou 310000Zhejiang ProvinceChina

BACKGROUND Targeted therapy(TT)has resulted in controversial efficacy as first-line treatment for biliary tract cancer(BTC).More efficacy comparisons are required to clarify the overall effects of chemotherapy(CT)combined with TT and CT alone on advanced *** To conduct a meta-analysis of the available evidence on the efficacy of CT combined with TT for advanced *** The PubMed,EMBASE,ClinicalTrials,Scopus and Cochrane Library databases were systematically searched for relevant studies published from inception to August *** randomized clinical trials(RCTs)including comparisons between the combination of gemcitabine-based CT with TT and CT alone as firstline treatment for advanced BTC were eligible(PROSPERO-CRD42022313001).The odds ratios(ORs)for the objective response rate(ORR)and hazard ratios(HRs)for both progression-free survival(PFS)and overall survival(OS)were calculated and *** analyses based on different targeted agents,CT regimens and tumor locations were *** Nine RCTs with a total of 1361 individuals were included and *** overall analysis showed a significant improvement in ORR in patients treated with CT+TT compared to those treated with CT alone(OR=1.43,95%CI:1.11-1.86,P=0.007)but no difference in PFS or *** trends were observed in the subgroup treated with agents targeting epidermal growth factor receptor(OR=1.67,95%CI:1.17-2.37,P=0.004)but not in the subgroups treated with agents targeting vascular endothelial growth factor receptor or mesenchymal-epithelial transition ***,patients who received a CT regimen of gemcitabine+oxaliplatin in the CT+TT arm had both a higher ORR(OR=1.75,95%CI:1.20-2.56,P=0.004)and longer PFS(HR=0.83,95%CI:0.70-0.99,P=0.03)than those in the CT-only ***,patients with cholangiocarcinoma treated with CT+TT had significantly increased ORR and PFS(ORR,OR=2.06,95%CI:1.27-3.35,PFS,HR=0.79,95%CI:0.66-0.94).CONCLUSION CT+TT is a potential first-line treat

关键词： Advanced biliary tract cancer Targeted therapy Chemotherapy Meta-analysis Randomized controlled trial First-line treatment

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Structure optimal design research on backfill hydraulic support

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Journal of Central South University 2017年第7期24卷 1637-1646页

作者： ZHANG Qiang ZHANG Ji-xiong QI Wen-yue zhou nan TAI Yang State Key Laboratory of Coal Resource and Safe Mining School of MinesChina University of Mining&TechnologyXuzhou 221116China

Backfill hydraulic support is the key equipment in achieving coal mining and solid backfilling simultaneously in solid backfill mining *** on the summary and analysis of main types,basic structural properties and filed application of backfill hydraulic support,this work has firstly proposed the basic principle of backfill hydraulic support optimization design and provided the method of optimal design of key structural components,like four-bar linkage,rear canopy and tamping structure;the method is further elaborated as changing hinging position of upper bar to optimize four-bar linkage,by lengthening or shortening the rear canopy to optimize length ratio of canopy;and by changing length and hinging position of tamping structure as well as suspension height of backfill scrape conveyor to realize optimization of tamping *** this basis,the process of optimal design of backfill hydraulic support is *** optimal design case of ZC5200/14.5/30 six columns-four bar linkage used in 7203 W workface of Zhaizhen Coal Mine shows that the backfill properties like horizontal roof gap,vertical horizontal gap,tamping angle and tamping head gap are improved obviously through optimizing four-bar linkage,canopy length and tamping structure according to the optimal design method proposed in this work.

关键词： backfill hydraulic support structure optimal design four-bar linkage rear canopy tamping structure

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Blast responses of polyurea retrofitted utility tunnel reinforced with basalt fibre reinforced polymer bars

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Defence Technology（防务技术） 2022年第5期18卷 755-771页

作者： Jian-nan zhou Xiao-shuo Chen Yin-zhi zhou Wen-ye Wang Peng Wang Xin-li Kong Ying Xu Han-sheng Geng Feng-nian Jin State Key Laboratory for Disaster Prevention&Mitigation of Explosion&Impact Army Engineering University of PLANanjing210007China

Polyurea coating and carbon fibre reinforced polymer reinforcing techniques were applied to retrofit a severely damaged urban utility tunnel(UUT).The blast responses of the retrofitted UUT were investigated through in-filed explosion experimental tests,and the displacements,strains,accelerations,and damage were *** retrofitted UUT exhibited comparable or even better blast resistance than the intact *** the polyurea coating was flexible,it exhibited excellent performance in improving the blast resistance of the damaged *** the UUT reinforced with basalt fibre reinforce polymer(BFRP)bars has smaller damage compared with the UUT reinforced with steel bars,its retrofitting is simple,and the cost is *** roof was simplified as an elastically simple support one-way *** beam theory was adopted to analyse the dynamic responses of UUT roof considering the interaction between soil and structure,which agree well with the experiments in the first three cases.

关键词： Urban utility tunnel Retrofitting Polyurea CFRP Explosion

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