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Characterization of Thermo-Physical Properties of Cement-Based Blocks of Varied Sand Types Using Cost-Effective Enhancement Approach
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作者 Eunice Akyereko Adjei Samuel Amos-Abanyie Siddig Omer 《Open Journal of Energy Efficiency》 2020年第1期14-30,共17页
The dominant property of building envelope fabric which contributes significantly to minimize electricity utilization in building is the thermo-physical properties. There is inadequate literature on representative pra... The dominant property of building envelope fabric which contributes significantly to minimize electricity utilization in building is the thermo-physical properties. There is inadequate literature on representative practical data of thermo-physical properties of the dominant building envelope components in Ghana. This study aims to use cost-effective approach to characterize the thermo-physical properties of only cement-based mortar and concrete blocks used in Ghana for building components specifically wall design. Mixed methods research design was employed to achieving the aim. A questionnaire survey was used among sampled building fabric components manufacturers to pick representative data on thermos-physical properties of their mortar and concrete blocks. Also, an experimental procedure employing a transient technique with a TCi Thermal Analyser was used to determine the thermo-physical properties of selected mortar and concrete blocks from Ghana in addition to designed parametric mortar and concrete blocks with varied ratios obtained from the survey were undertaken at University of Nottingham. From the study, a trend of decreasing thermal conductivity and thermal effusivity with corresponding decreasing sand content was observed with all the different sand types. The thermal conductivities of both mortar and concrete parametric blocks meet the range of expected standard values outlined in Chattered Institute of Building Services Engineers (CIBSE) Guide A. The major limitation of the work is the dimension of the sample size;which is not inconsistent with standard block size due to the experimental setup used. It is expected that, the characterization of the predominant cement-based building fabrics components will contribute to improved building performance analysis with significant savings in electricity utilization for space cooling. 展开更多
关键词 Building Envelop THERMAL Conductivity THERMAL Effusivity TCI THERMAL Analyser cement-based Fabric COST-EFFECTIVE ENHANCEMENT APPROACH Ghana
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Reinforcing effects of polypropylene on energy absorption and fracturing of cement-based tailings backfill under impact loading
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作者 Jiajian Li Shuai Cao Erol Yilmaz 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2024年第4期650-664,共15页
Polypropylene(PP)fiber-reinforced cement-based tailings backfill(FRCTB)is a green compound material with superior crack resistance and has good prospects for application in underground mining.However,FRCTB exhibits su... Polypropylene(PP)fiber-reinforced cement-based tailings backfill(FRCTB)is a green compound material with superior crack resistance and has good prospects for application in underground mining.However,FRCTB exhibits susceptibility to dynamic events,such as impact ground pressure and blast vibrations.This paper investigates the energy and crack distribution behavior of FRCTB under dynamic impact,considering the height/diameter(H/D)effect.Split Hopkinson pressure bar,industrial computed tomography scan,and scanning electron microscopy(SEM)experiments were carried out on six types of FRCTB.Laboratory outcomes confirmed fiber aggregation at the bottom of specimens.When H/D was less than 0.8,the proportion of PP fibers distributed along theθangle direction of80°-90°increased.For the total energy,all samples presented similar energy absorption,reflectance,and transmittance.However,a rise in H/D may cause a rise in the energy absorption rate of FRCTB during the peak phase.A positive correlation existed between the average strain rate and absorbed energy per unit volume.The increase in H/D resulted in a decreased crack volume fraction of FRCTB.When the H/D was greater than or equal to 0.7,the maximum crack volume fraction of FRCTB was observed close to the incidence plane.Radial cracks were present only in the FRCTB with an H/D ratio of 0.5.Samples with H/D ratios of 0.5 and 0.6 showed similar distributions of weakly and heavily damaged areas.PP fibers can limit the emergence and expansion of cracks by influencing their path.SEM observations revealed considerable differences in the bonding strengths between fibers and the FRCTB.Fibers that adhered particularly well to the substrate were attracted together with the hydration products adhering to surfaces.These results show that FRCTB is promising as a sustainable and green backfill for determining the design properties of mining with backfill. 展开更多
关键词 cement-based tailings fiber-reinforced backfills FRACTURE energy absorption impact loading
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分组密码算法uBlock积分攻击的改进
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作者 王晨 崔佳敏 +1 位作者 李木舟 王美琴 《电子与信息学报》 EI CAS CSCD 北大核心 2024年第5期2149-2158,共10页
积分攻击是由Daemen等人(doi:10.1007/BFb0052343)于1997年提出的一种密码分析方法,是继差分分析和线性分析之后最有效的密码分析方法之一。作为2018年全国密码算法设计竞赛分组算法的获胜算法,uB-lock抵抗积分攻击的能力受到较多的关... 积分攻击是由Daemen等人(doi:10.1007/BFb0052343)于1997年提出的一种密码分析方法,是继差分分析和线性分析之后最有效的密码分析方法之一。作为2018年全国密码算法设计竞赛分组算法的获胜算法,uB-lock抵抗积分攻击的能力受到较多的关注。为了重新评估uBlock家族密码算法抵抗积分攻击的安全性,该文利用单项式传播技术,结合混合整数线性规划(MILP)工具搜索积分区分器,并利用部分和技术进行密钥恢复攻击。对于uBlock-128/128和uBlock-128/256,基于搜索到的9轮积分区分器分别进行了首个11轮和12轮攻击,数据复杂度为2~(127)选择明文,时间复杂度分别为2~(127.06)和2~(224)次加密,存储复杂度分别为2~(44.58)和2~(138)字节;对于uBlock-256/256,基于搜索到的10轮积分区分器进行了首个12轮攻击,数据复杂度为2~(253)选择明文,时间复杂度为2~(253.06)次加密,存储复杂度为2~(44.46)字节。与之前uBlock的最优积分攻击结果相比,uBlock-128/128和uBlock-256/256的攻击轮数分别提高2轮,uBlock-128/256的攻击轮数提高3轮。本文的攻击说明,uBlock针对积分攻击依然有足够的安全冗余。 展开更多
关键词 密码分析 分组密码 ublock 积分攻击
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Twin-Block双期矫治与单纯直丝弓矫正技术在早期下颌后缩矫正患儿中的疗效对比
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作者 田华 邓刚 郝天喜 《中国医疗美容》 2024年第1期66-70,共5页
目的探讨Twin-Block双期矫治与单纯直丝弓矫正技术在替牙及恒牙早期错(牙合)畸形矫正患儿中的疗效对比。方法选取我院2020年9月到2023年9月收治的60例恒牙早期错(牙合)畸形患儿作为研究对象,按照治疗方法不同分为观察组与对照组,各组均... 目的探讨Twin-Block双期矫治与单纯直丝弓矫正技术在替牙及恒牙早期错(牙合)畸形矫正患儿中的疗效对比。方法选取我院2020年9月到2023年9月收治的60例恒牙早期错(牙合)畸形患儿作为研究对象,按照治疗方法不同分为观察组与对照组,各组均为30例。所有患儿均采取矫正治疗,对照组患儿采取直丝弓矫正技术进行治疗,观察组患儿采取Twin-Block矫治器及直丝弓矫治技术进行双期治疗。对比两组患儿临床疗效,及矫治时间,治疗前头影测量及关节改建情况,采用口腔锥形束扫描成像进行检测两组患儿关节窝宽径、关节前间隙、关节后间隙、关节上间隙、髁突前后径、髁突高度相关参数表达水平,最后对比两组患儿治疗前后上下齿槽座(ANB)角、下齿槽座(SNB)角、上齿槽座(SNA)角、下颌平面角(Mp-SN)、下颌综合长度(Ar-Po)、下颌升支高度(Ar-Go)、下颌体长(Go-Gn)、上中切牙-SN平面角(U1-SN)、下中切牙-下颌平面角(L1-Mp)、上唇审美平面距(Ls-E)、下唇审美平面距(Li-E)、鼻唇角。结果观察组治疗总有效率96.67%明显高于对照组76.67%(P<0.05);治疗后,观察组矫治时间长于对照组(P<0.05);治疗前,两组患儿关节窝宽径、关节前间隙、关节后间隙、关节上间隙、髁突前后径、髁突高度对比无明显差异(P>0.05),治疗后,两组患儿关节窝宽径对比无明显差异,关节前间隙减小,观察组(1.21±0.28)mm高于对照组,关节后间隙、关节上间隙、髁突前后径、髁突高度均增加,且观察组高于对照组(P<0.05);治疗前,两组患儿ANB角、SNB角、SNA角、Mp-SN、Ar-Po、Ar-Go、Go-Gn、U1-SN、L1-Mp、Ls-E、Li-E、鼻唇角对比无明显差异(P>0.05),治疗后,两组患儿SNB、Mp-SN、Ar-Po、Ar-Go、Go-Gn、鼻唇角均增大,ANB、U1-SN、L1-Mp、Li-E、Ls-E减小,且观察组变化大于对照组(P<0.05)。结论Twin-Block矫治器配合直丝弓矫治技术双期矫治器与单纯直丝弓矫正技术相比治疗替牙及恒牙早期错(牙合)畸形疗效显著,可作为儿童恒牙早期错(牙合)畸形的首选治疗方案。 展开更多
关键词 TWIN-block矫治器 直丝弓矫正 恒牙早期 错(牙合)畸形 咀嚼功能
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Copper Ions Removal from Wastewater by Electrocoagulation Using Cement-based Cathode Plates
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作者 YOU Song WU Jing +5 位作者 WANG Shizhe WANG Wei LI Qiong ZAHNG Ganggang DING Qinjun WANG Luoxin 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第2期387-393,共7页
The present work uses PEO solution to well disperse carbon fiber and identifies percolation thresholds of carbon fiber and carbon black which are used as conductive fillers.The resultant cathode plates have an average... The present work uses PEO solution to well disperse carbon fiber and identifies percolation thresholds of carbon fiber and carbon black which are used as conductive fillers.The resultant cathode plates have an average compressive strength of 27.3 MPa and flexural strength of 29.09 MPa,which demonstrate excellent mechanical properties.The Cu^(2+)removal efficiency was measured at different current densities in EC process with cement-based cathode plate,while the voltage changes were recorded.The results showed that the cement-based cathode plate operated stably and achieved 99.7%removal of 1 L of simulated wastewater with a Cu^(2+)concentration of 200 ppm at a current density of 8 m A/cm^(2)for 1 h.Characterization of floc and tested cathode plates,SEM and EDS analyses,and repeatability testing of the tested plates demonstrate the reusability of the plates,proving that cement-based plates can effectively replace metal cathode plates,reduce the cost of EC and improve the applicability of EC devices. 展开更多
关键词 ELECTROCOAGULATION cathode plate cement-based conductive materials copper ions repeatability
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Experimental and Numerical Research on Water Transport during Adsorption and Desorption in Cement-Based Materials
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作者 Xiang Zhang Miao Su +3 位作者 Wenjie Yu Zhen Lei Jun Ren Juntong Qu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第8期1487-1507,共21页
The durability of cement-based materials is related to water transport and storage in their pore network under different humidity conditions.To understand the mechanism and characteristics of water adsorption and deso... The durability of cement-based materials is related to water transport and storage in their pore network under different humidity conditions.To understand the mechanism and characteristics of water adsorption and desorption processes from the microscopic scale,this study introduces different points of view for the pore space model generation and numerical simulation of water transport by considering the“ink-bottle”effect.On the basis of the pore structure parameters(i.e.,pore size distribution and porosity)of cement paste and mortar with water-binder ratios of 0.3,0.4 and 0.5 obtained via mercury intrusion porosimetry,randomly formed 3D pore space models are generated using two-phase transformation on Gaussian random fields and verified via image analysis method of mathematical morphology.Considering the Kelvin-Laplace equation and the influence of“ink-bottle”pores,two numerical calculation scenarios based on mathematical morphology are proposed and applied to the generated model to simulate the adsorption-desorption process.The simulated adsorption and desorption curves are close to those of the experiment,verifying the effectiveness of the developed model and methods.The obtained results characterize water transport in cement-based materials during the variation of relative humidity and further explain the hysteresis effect due to“ink-bottle”pores from the microscopic scale. 展开更多
关键词 cement-based material adsorption and desorption ink-bottle effect pore space modeling mathematical morphology
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Effect of Glutinous Rice Flour on Mechanical Properties and Microstructure of Cement-based Materials
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作者 FENG Qi LU Bao WANG Dan 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第2期394-400,共7页
The mechanism of glutinous rice flour,a kind of natural admixture,on the hydration process,setting time,and microstructure of the Portland cement was investigated.The experimental results show that the glutinous rice ... The mechanism of glutinous rice flour,a kind of natural admixture,on the hydration process,setting time,and microstructure of the Portland cement was investigated.The experimental results show that the glutinous rice flour has an obvious setting retarding effect on cement pastes.The optimal dosage of the glutinous rice flour is 3wt%.In this case,the initial and final setting time of the paste are delayed by 140 and185 min,respectively.The flexural and compressive strengths of the hardened paste are increased by 0.35%and 0.07%after 56 d of curing.The glutinous rice flour hinders the mineral dissolution process and decreases the concentration of calcium ion at the initial stage of hydration due to the complexation effect,thereby hindering the nucleation and growth of CH and C-S-H phases and prolonging the hydration process.However,C-S-H phases combine with the glutinous rice flour to contribute the bonding effect together,which compacts the microstructure of hardened cement pastes at the later hydration stage of cement pastes.Thus,in-depth investigation on the utilization of glutinous rice flour as the admixture for the Portland cement is expected to be meaningful for the control of hydration exothermic rate and setting time. 展开更多
关键词 glutinous rice flour cement-based materials mechanical properties setting time
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Effects of Strain Rate and Fiber Content on the Dynamic Mechanical Properties of Sisal Fiber Cement-Based Composites
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作者 Yubo Zhang Ping Lei +1 位作者 Lina Wang Jiqing Yang 《Journal of Renewable Materials》 SCIE EI 2023年第1期393-410,共18页
In this paper,a split Hopkinson pressure bar(SHPB)was used to investigate the dynamic impact mechanical behavior of sisal fiber-reinforced cement-based composites(SFRCCs),and the microscopic damage evolution of the co... In this paper,a split Hopkinson pressure bar(SHPB)was used to investigate the dynamic impact mechanical behavior of sisal fiber-reinforced cement-based composites(SFRCCs),and the microscopic damage evolution of the composites was analyzed by scanning electron microscopy(SEM)and energy-dispersive X-ray spectrome-try(EDS).The results show that the addition of sisal fibers improves the impact resistance of cement-based composite materials.Compared with ordinary cement-based composites(OCCs),the SFRCCs demonstrate higher post-peak strength,ductility,and energy absorption capacity with higher fiber content.Moreover,the SFRCCs are strain rate sensitive materials,and their peak stress,ultimate strain,and energy integrals all increase with increasing strain rate.From the perspective of fracture failure characteristics,the failure of OCCs is dominated by the brittle failure of crystal cleavage.In contrast,the failure mode of the SFRCCs changes to microscale matrix cracks,multi-scale pull-out interface debonding of fibers(fine filaments and bundles),and mechanical interlock.This research provides an experimental basis for the engineering application of high-performance and green cement-based composites. 展开更多
关键词 Sisal fiber cement-based composites SHPB energy integration microstructure damage evolution law
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Novel approach of ultrasound-guided lateral recess block for a patient with lateral recess stenosis: A case report 被引量:1
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作者 Jiao Yang Xin-Ling Li Qing-Bing Li 《World Journal of Clinical Cases》 SCIE 2024年第5期1010-1017,共8页
BACKGROUND Ultrasound guide technology,which can provide real-time visualization of the needle tip and tissues and avoid many adverse events,is widely used in mini-mally invasive therapy.However,the studies on ultraso... BACKGROUND Ultrasound guide technology,which can provide real-time visualization of the needle tip and tissues and avoid many adverse events,is widely used in mini-mally invasive therapy.However,the studies on ultrasound-guided Lateral recess block(LRB)are limited,this is probably because there is no recognized standard method for ultrasound scanning.This study aimed to evaluate the effect of ultrasound-guided LRB in patients with lateral recess stenosis(LRS).CASE SUMMARY A 65-year-old patient complained of low back pain accompanied occasionally by pain and numbness in the left lower limb.Physical examination showed ten-derness on the spinous process and paraspinal muscles from L1 to S1,extensor hallucis longus and tibialis anterior weakness(muscle strength:4-),and a positive straight leg raising test in the left lower limb(60°).Magnetic resonance imaging showed L4–L5 disc degeneration with left LRS and nerve root entrapment.Subsequently,the patient was diagnosed with LRS.This patient was treated with a novel ultrasound-guided LRB approach.The patient’s symptoms significantly improved without any complications at 1 wk postoperatively and at the 3-month follow-up.CONCLUSION This is the first report on the LRS treatment with ultrasound-guided LRB from the contralateral spinous process along the inner side of the articular process by out-plane technique.Further studies are expected to investigate the efficacy and safety of ultrasound-guided LRB for patients with LRS. 展开更多
关键词 Lateral recess stenosis ULTRASOUND Lateral recess block Real-time visualization Low back pain Case report
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A nanobody-based blocking enzyme-linked immunosorbent assay for detecting antibodies against pseudorabies virus glycoprotein E
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作者 Huanhuan Lü Pinpin Ji +6 位作者 Siyu Liu Ziwei Zhang Lei Wang Yani Sun Baoyuan Liu Lizhen Wang Qin Zhao 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第4期1354-1368,共15页
Pseudorabies(PR)is an acute infectious disease of pigs caused by the PR virus(PRV)and results in great economic losses to the pig industry worldwide.PRV glycoprotein E(gE)-based enzyme-linked immunosorbent assay(ELISA... Pseudorabies(PR)is an acute infectious disease of pigs caused by the PR virus(PRV)and results in great economic losses to the pig industry worldwide.PRV glycoprotein E(gE)-based enzyme-linked immunosorbent assay(ELISA)has been used to distinguish gE-deleted vaccine-immunized pigs from wild-type virus-infected pigs to eradicate PR in some countries.Nanobody has the advantages of small size and easy genetic engineering and has been a promising diagnostic reagent.However,there were few reports about developing nanobody-based ELISA for detecting anti-PRV-gE antibodies.In the present study,the recombinant PRV-gE was expressed with a bacterial system and used to immunize the Bactrian camel.Then,two nanobodies against PRV-gE were screened from the immunized camel by phage display technique.Subsequently,two nanobody-HRP fusion proteins were expressed with HEK293T cells.The PRV-gE-Nb36-HRP fusion protein was selected as the probe for developing the blocking ELISA(bELISA)to detect anti-PRV-gE antibodies.Through optimizing the conditions of bELISA,the amount of coated antigen was 200 ng per well,and dilutions of the fusion protein and tested pig sera were separately 1:320 and 1:5.The cut-off value of bELISA was 24.20%,and the sensitivity and specificity were 96.43 and 92.63%,respectively.By detecting 233 clinical pig sera with the developed bELISA and a commercial kit,the results showed that the coincidence rate of two assays was 93.99%.Additionallly,epitope mapping showed that PRV-gE-Nb36 recognized a conserved conformational epitope in different reference PRV strains.Simple,great stability and low-cost nanobody-based bELISA for detecting anti-PRV-gE antibodies were developed.The bELISA could be used for monitoring and eradicating PR. 展开更多
关键词 NANOBODY nanobody-HRP blocking ELISA PRV-gE ANTIBODY
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Ultrasound-guided sphenopalatine ganglion block for effective analgesia during awake fiberoptic nasotracheal intubation: A case report
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作者 Hangil Kang Seongjae Park Yehun Jin 《World Journal of Clinical Cases》 SCIE 2024年第14期2451-2456,共6页
BACKGROUND Awake fiberoptic nasotracheal intubation(AFNI)is the preferred airway ma-nagement strategy for patients with difficult airways.However,this procedure can cause significant physical and psychological distres... BACKGROUND Awake fiberoptic nasotracheal intubation(AFNI)is the preferred airway ma-nagement strategy for patients with difficult airways.However,this procedure can cause significant physical and psychological distress.This case report explores the application of a sphenopalatine ganglion(SPG)block as an alternative anal-gesic modality to mitigate the discomfort associated with AFNI.CASE SUMMARY A 63-year-old female with a history of right maxillary osteosarcoma underwent craniotomy for a suspected malignant brain lesion.The patient’s medical history included prior surgery,chemotherapy,and radiation therapy,resulting in signi-ficant jaw impairment and limited neck mobility.Considering the anticipated air-way challenges,AFNI was planned.A SPG block was performed under real-time ultrasound guidance,providing effective analgesia during nasotracheal intuba-tion.CONCLUSION The SPG block represents a promising analgesic approach in AFNI,offering po-tential benefits in alleviating pain involving the nasal and nasopharyngeal regions as well as improving patient cooperation. 展开更多
关键词 Sphenopalatine ganglion block Nerve block Regional anesthesia ANALGESIA Awake fiberoptic nasotracheal intubation Case report
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General Method of Combining Grover and Simon for Attacking Block Ciphers
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作者 Fu Xiangqun Bao Wansu +1 位作者 Shi Jianhong Li Tan 《China Communications》 SCIE CSCD 2024年第6期237-245,共9页
The compatibility of different quantum algorithms should be considered when these algorithms are combined.In this paper,the method of combining Grover and Simon is studied for the first time,under some preconditions o... The compatibility of different quantum algorithms should be considered when these algorithms are combined.In this paper,the method of combining Grover and Simon is studied for the first time,under some preconditions or assumptions.First,we give two preconditions of applying Grover’s algorithm,which ensure that the success probability of finding the marked element is close to 1.Then,based on these two preconditions,it is found out that the success probability of the quantum algorithm for FXconstruction is far less than 1.Furthermore,we give the design method of the Oracle function,and then present the general method of combining Grover and Simon algorithm for attacking block ciphers,with success probability close to 1. 展开更多
关键词 block ciphers post-quantum crypto quantum algorithms
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An Encode-and CRT-Based Scalability Scheme for Optimizing Transmission in Blockchain
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作者 Qianqi Sun Fenhua Bai 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期1733-1754,共22页
Blockchain technology has witnessed a burgeoning integration into diverse realms of economic and societal development.Nevertheless,scalability challenges,characterized by diminished broadcast efficiency,heightened com... Blockchain technology has witnessed a burgeoning integration into diverse realms of economic and societal development.Nevertheless,scalability challenges,characterized by diminished broadcast efficiency,heightened communication overhead,and escalated storage costs,have significantly constrained the broad-scale application of blockchain.This paper introduces a novel Encode-and CRT-based Scalability Scheme(ECSS),meticulously refined to enhance both block broadcasting and storage.Primarily,ECSS categorizes nodes into distinct domains,thereby reducing the network diameter and augmenting transmission efficiency.Secondly,ECSS streamlines block transmission through a compact block protocol and robust RS coding,which not only reduces the size of broadcasted blocks but also ensures transmission reliability.Finally,ECSS utilizes the Chinese remainder theorem,designating the block body as the compression target and mapping it to multiple modules to achieve efficient storage,thereby alleviating the storage burdens on nodes.To evaluate ECSS’s performance,we established an experimental platformand conducted comprehensive assessments.Empirical results demonstrate that ECSS attains superior network scalability and stability,reducing communication overhead by an impressive 72% and total storage costs by a substantial 63.6%. 展开更多
关键词 blockchain network coding block compression transmission optimization
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Geochemistry, zircon U–Pb geochronology, and Hf isotopes of S-type granite in the Baoshan block, constraints on the age and evolution of the Proto-Tethys
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作者 Jianjun Zhang Chuanlong Mou +3 位作者 Chendong Liu Yong Zhang Ting Chen Hualiang Li 《Acta Geochimica》 EI CAS CSCD 2024年第1期40-58,共19页
Geochemistry, zircon U–Pb geochronology, and Hf isotope data for the Early Paleozoic granites in the Baoshan Block reveal the Early Paleozoic tectonic evolution of the Proto-Tethys. The samples are high-K, calcalkali... Geochemistry, zircon U–Pb geochronology, and Hf isotope data for the Early Paleozoic granites in the Baoshan Block reveal the Early Paleozoic tectonic evolution of the Proto-Tethys. The samples are high-K, calcalkaline, strongly peraluminous rocks with A/CNK values of 1.37–1.46, are enriched in SiO2, K2O, and Rb, and are depleted in Nb, P, Ti, Eu, and heavy rare earth elements,which indicates the crystallization fractionation of the granitic magma. Zircon U–Pb dating indicates that they formed in ca. 480 Ma. The Nansa granites have εHf(t) values ranging from-16.04 to 4.36 with corresponding TC DMages of 2.10–0.81 Ga, which suggests the magmas derived from the partial melting of ancient metasedimentary with minor involvement of mantle-derived components. A synthesis of data for the Early Paleozoic igneous rocks in the Baoshan block and adjacent(Tengchong,Qiangtang, Sibumasu, Himalaya, etc.) blocks indicates that these blocks were all aligned along the proto-Tethyan margin of East Gondwana in the Early Paleozoic. The Early Paleozoic S-type granites from Nansa were generated in a high-temperature and low-pressure(HTLP) extensional tectonic setting, which resulted from Andean-type orogeny instead of the final assembly of Gondwana or crustal extension in a non-arc environment. In certain places, an expanding environment may exist in opposition to the tectonic backdrop of the lithosphere’s thickening and shortening, leading the crust to melt and decompress,mantle-derived materials to mix, and a small quantity of peraluminous granite to emerge. 展开更多
关键词 Baoshan block Early Paleozoic GRANITE GEOCHEMISTRY ZIRCON GEOCHRONOLOGY Hf isotope
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Manipulation of internal blockage in triangular triple quantum dot
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作者 齐月 魏建华 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期588-593,共6页
We utilize the calculation of hierarchical equations of motion to demonstrate that the spin-dependent properties between adjacent quantum dots(QDs)can be changed by breaking the internal symmetry configuration,corresp... We utilize the calculation of hierarchical equations of motion to demonstrate that the spin-dependent properties between adjacent quantum dots(QDs)can be changed by breaking the internal symmetry configuration,corresponding to the inversion of dominant chiral states.In the linear triple quantum dots(LTQDs)connected to two electron reservoirs,we can observe that the blockage appears at the triangle triple quantum dots(TTQDs)by gradually increasing the coupling strength between next-nearest double QDs.When the initial coupling between LTQDs has altered,the internal chiral circulation also undergoes the corresponding transform,thus achieving qualitative regulation and detection of the blocking region.We also investigate the response of the chiral circulation to the dot–lead coupling strength,indicating the overall robust chiral circulation of the TTQDs frustration. 展开更多
关键词 quantum dots chiral topology blocking
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The late Early-Paleozoic granitic magmatism in Northwestern Fujian, China: constraints on intraplate orogeny in the South China block
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作者 WanLi Gao ZongXiu Wang 《Acta Geochimica》 EI CAS CSCD 2024年第1期134-149,共16页
The Early Paleozoic tectono-thermal event was a significant orogenic activity during the Phanerozoic era,which had a profound impact on the early crust of the South China Block(SCB) and established the foundation for ... The Early Paleozoic tectono-thermal event was a significant orogenic activity during the Phanerozoic era,which had a profound impact on the early crust of the South China Block(SCB) and established the foundation for later tectonic activity.The Wuyi-Yunkai orogenic belt in Southeastern China was extensively exposed to Early Paleozoic magmatism,the genetic mechanism of which remains controversial.To shed light on this issue,detailed petrological,geochemical,and zircon U-Pb-Hf isotopic studies were carried out on two granitoids,namely the Yuntongshan pluton and the Gaoqiao pluton,identified in the central Wuyishan.Zircon U-Pb chronology of the Yuntongshan and Gaoqiao bodies yielded ages of437±4 Ma(MSWD=2.2) and 404±2 Ma(MSWD=12),respectively,indicating that they were emplaced during the Early Silurian and Early Devonian periods.These granitoids are primarily composed of biotite-granite and biotite-monzonitic-granites,with high concentrations of S_(i)O_(2)(73.59-75.91 wt%),K_(2)O+Na_(2)O(8.31-8.73wt%),and low contents of MgO,CaO,Cr,Ni.They are classified as high-K calc-alkaline and weakly metaluminous-strongly peraluminous S-type granites.These granitoids are enriched in light rare earth elements(LREEs) and large ion lithophile elements(LILEs) and depleted in heavy rare earth elements(HREEs) and high field strength elements(HFSEs) with arc affinity.The εHf(t) values of-3.3 to-15.4 with two-stage Hf model ages ranging from 2829 to 1644 Ma,combined with the presence of Neoproterozoic inherited zircons,suggest that the primary magma of these granitoids was derived from the partial melting of Neoproterozoic crust with a Paleoproterozoic crustal model age.These findings,combined with the spatio-temporal distribution of regional magmatism,reveal that the late Early-Paleozoic granitoids formed in the intraplate orogenic background originating from the subduction of the proto-Tethys Ocean and proto-Pacific Ocean around the margin of the east Gondwana supercontinent. 展开更多
关键词 Late Early-Paleozoic GRANITES Intraplate orogeny Cathysian block Zircon U-Pb-Hf Isotopic composition
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Investigation of the block toppling evolution of a layered model slope by centrifuge test and discrete element modeling
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作者 Leilei Jin Hongkai Dong +3 位作者 Fei Ye Yufeng Wei Jianfeng Liu Changkui Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第1期112-122,共11页
Primary toppling usually occurs in layered rock slopes with large anti-dip angles.In this paper,the block toppling evolution was explored using a large-scale centrifuge system.Each block column in the layered model sl... Primary toppling usually occurs in layered rock slopes with large anti-dip angles.In this paper,the block toppling evolution was explored using a large-scale centrifuge system.Each block column in the layered model slope was made of cement mortar.Some artificial cracks perpendicular to the block column were prefabricated.Strain gages,displacement gages,and high-speed camera measurements were employed to monitor the deformation and failure processes of the model slope.The centrifuge test results show that the block toppling evolution can be divided into seven stages,i.e.layer compression,formation of major tensile crack,reverse bending of the block column,closure of major tensile crack,strong bending of the block column,formation of failure zone,and complete failure.Block toppling is characterized by sudden large deformation and occurs in stages.The wedge-shaped cracks in the model incline towards the slope.Experimental observations show that block toppling is mainly caused by bending failure rather than by shear failure.The tensile strength also plays a key factor in the evolution of block toppling.The simulation results from discrete element method(DEM)is in line with the testing results.Tensile stress exists at the backside of rock column during toppling deformation.Stress concentration results in the fragmented rock column and its degree is the most significant at the slope toe. 展开更多
关键词 block toppling CENTRIFUGE Anti-dip slope Failure mechanism Discrete element method
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Greatly enhanced corrosion/wear resistances of epoxy coating for Mg alloy through a synergistic effect between functionalized graphene and insulated blocking layer
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作者 Z.Y.Xue X.J.Li +3 位作者 J.H.Chu M.M.Li D.N.Zou L.B.Tong 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第1期332-344,共13页
The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various industries.The conventional epoxy coating easily forms many intrinsic defects during the solidification proc... The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various industries.The conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient protection.In the current study,we design a double-layer epoxy composite coating on Mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly technique.The outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)film.The FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier capability.The Ce film connects the outer layer with the substrate,showing the transition effect.The corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare Mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling behavior.The synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of Mg alloys. 展开更多
关键词 Mg alloy Functionalized graphene Epoxy coating Corrosion/wear resistance blocking layer
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Reversal of complete atrioventricular block in dialysis patients following parathyroidectomy:A case report
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作者 Shan-Shan Xu Li-Hai Hao Yan-Meng Guan 《World Journal of Clinical Cases》 SCIE 2024年第7期1313-1319,共7页
BACKGROUND Refractory secondary hyperparathyroidism(SHPT)is a common complication observed in patients with end-stage renal disease and can result in ectopic calcification.Metastatic calcification involving the heart ... BACKGROUND Refractory secondary hyperparathyroidism(SHPT)is a common complication observed in patients with end-stage renal disease and can result in ectopic calcification.Metastatic calcification involving the heart valves and the conduction system can easily lead to arrhythmias,including atrioventricular block.This case report describes a maintenance hemodialysis patient with refractory SHPT resulting in a complete atrioventricular block(CAVB),which was eventually reversed to a first-degree atrioventricular block.CASE SUMMARY We present the case of a 31-year-old Asian female who was receiving maintenance hemodialysis because of lupus nephropathy.She developed SHPT,and an electrocardiogram revealed a first-degree atrioventricular block.Then,she underwent parathyroidectomy(PTX)with autotransplantation.Unfortunately,a few years later,she developed SHPT again,and an electrocardiogram revealed a CAVB.A few years after the second PTX surgery,the calcification of the left atrium and left ventricle improved,and her CAVB was reversed.CONCLUSION This case revealed that metastatic cardiac calcification can result in complete atrioventricular blockage.Following parathyroid surgery,calcification of the cardiac conduction system improved,leading to reversal of the atrioventricular block.It is important for dialysis patients to optimize intact parathyroid hormone therapy and pay attention to calcification metastasis. 展开更多
关键词 Secondary hyperparathyroidism Ectopic calcification Atrioventricular block REVERSAL Case report
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Databases of 2D material-substrate interfaces and 2D charged building blocks
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作者 邓俊 潘金波 杜世萱 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期34-38,共5页
Discovery of materials using“bottom-up”or“top-down”approach is of great interest in materials science.Layered materials consisting of two-dimensional(2D)building blocks provide a good platform to explore new mater... Discovery of materials using“bottom-up”or“top-down”approach is of great interest in materials science.Layered materials consisting of two-dimensional(2D)building blocks provide a good platform to explore new materials in this respect.In van der Waals(vdW)layered materials,these building blocks are charge neutral and can be isolated from their bulk phase(top-down),but usually grow on substrate.In ionic layered materials,they are charged and usually cannot exist independently but can serve as motifs to construct new materials(bottom-up).In this paper,we introduce our recently constructed databases for 2D material-substrate interface(2DMSI),and 2D charged building blocks.For 2DMSI database,we systematically build a workflow to predict appropriate substrates and their geometries at substrates,and construct the 2DMSI database.For the 2D charged building block database,1208 entries from bulk material database are identified.Information of crystal structure,valence state,source,dimension and so on is provided for each entry with a json format.We also show its application in designing and searching for new functional layered materials.The 2DMSI database,building block database,and designed layered materials are available in Science Data Bank at https://doi.org/10.57760/sciencedb.j00113.00188. 展开更多
关键词 2D material-substrate interfaces charged building block database functional-oriented materials design layered materials density functional theory
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