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Carbon Emission Effects Driven by Evolution of Chinese Dietary Structure from 1987 to 2020 被引量:1
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作者 ZHU Yuanyuan ZHANG Yan ZHU Xiaohua 《Chinese Geographical Science》 SCIE CSCD 2024年第1期181-194,共14页
Exploring carbon emission effects based on the evolution of residents’ dietary structure to achieve the carbon neutrality goal and mitigate climate change is an important task.This study took China as the research ob... Exploring carbon emission effects based on the evolution of residents’ dietary structure to achieve the carbon neutrality goal and mitigate climate change is an important task.This study took China as the research object(data excluding Hong Kong,Macao and Taiwan) and used the carbon emission coefficient method to quantitatively measure the food carbon emissions from 1987–2020,then analyzed the carbon emission effects under the evolution of dietary structure.The results showed that during the study period,the Chinese dietary structure gradually changed to a high-carbon consumption pattern.The dietary structure of urban residents developed to a balanced one,while that of rural residents developed to a high-quality one.During the study period,the per capita food carbon emissions and total food consumption of Chinese showed an increasing trend.The per capita food carbon emissions of residents in urban and rural showed an overall upward trend.The total food carbon emissions in urban increased significantly,while that in rural increased first and then decreased.The influence of beef and mutton on carbon emissions is the highest in dietary structure.Compared with the balanced dietary pattern,the food carbon emissions of Chinese residents had not yet reached the peak,but were evolving to a high-carbon consumption pattern. 展开更多
关键词 dietary structure structural evolution carbon emission effects carbon neutrality China
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The structural characteristics of dietary fibers from Tremella fuciformis and their hypolipidemic effects in mice 被引量:9
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作者 Shanshan Zhang Xinle Xu +1 位作者 Xu Cao Tingting Liu 《Food Science and Human Wellness》 SCIE CSCD 2023年第2期503-511,共9页
In this study,Tremella fuciformis residues as raw material,dietary fibers from tremella were prepared by multiple enzymes.The structure of dietary fibers from tremella was studied by Fourier transform infrared(FTIR),X... In this study,Tremella fuciformis residues as raw material,dietary fibers from tremella were prepared by multiple enzymes.The structure of dietary fibers from tremella was studied by Fourier transform infrared(FTIR),X-ray diffraction analysis(XRD)and scanning electron microscopy(SEM).We analyzed their lipidlowering properties in vitro(water holding,oil holding swelling cholesterol and sodium cholate binding capacitises)and the hypolipidemic effects in mice.The results showed that tremella dietary fibers presented the infrared absorption spectrum characteristics of polysaccharides and the characteristic diffraction peaks of cellulose type I.SEM results indicated that the surface of insoluble dietary fiber(IDF)was porous,while the soluble dietary fiber(SDF)was relatively compact and spongy.IDF exhibited significantly higher water holding,oil holding,and swelling binding capacities than the corresponding SDF.However,SDF exhibited significantly higher viscosity than IDF.The results showed tremella dietary fibers were significant in swelling,water holding and oil holding,cholesterol and bile acids.In vivo experiment results in mice indicated that SDF has the best effect on hyperlipidemia mice than IDF and total dietary fiber(TDF).SDF showed that the total cholesterol(TC),triglyceride(TG)and low density lipoprotein cholesterol(LDL-C)contents dropped by 28.33%,18.65%,and 48.97%,respectively,while high density lipoprotein cholesterol(HDL-C)content increased by 43.80%.Compared with the high-fat control(HCM)group,the arteriosclerosis index(AI)and liver index(LI)of the SDF group mice showed significant differences,indicating that SDF has a good auxiliary effect of lowering blood lipids.The administration of tremella fibers improved the lipid metabolism disorderly situation of hyperlipidemia mice.These results provide a reference for further research and rational development of T.fuciformis. 展开更多
关键词 Tremella fuciformis Dietary fiber structural characterization Hypolipidemic effects
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Analysis of level structure and monopole effects in Ca isotopes
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作者 Jin Li Ai-Xi Chen +1 位作者 Amir Jalili Han-Kui Wang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第10期161-167,共7页
Understanding the properties of nuclei near the double magic nucleus^(40)Ca is crucial for both nuclear theory and experiments.In this study,Ca isotopes were investigated using an extended pairing-plus-quadrupole mode... Understanding the properties of nuclei near the double magic nucleus^(40)Ca is crucial for both nuclear theory and experiments.In this study,Ca isotopes were investigated using an extended pairing-plus-quadrupole model with monopole corrections.The negative-parity states of^(44)Ca were coupled with the intruder orbital g_(9/2)at 4 MeV.The values of E_(4+)/E_(2+)agree well with experimental trend from^(42)Ca to^(50)Ca,considering monopole effects between νf_(7/2)and νp_(3/2)(νf_(5/2)).This monopole effect,determined from data of^(48)Ca and^(50)Ca,supports the proposed new nuclear magic number N=34 by predicting a high-energy 2^(+)state in^(54)Ca. 展开更多
关键词 Shell model Doubly magic ISOTOPES Monopole effects Level structure
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Effect of strain on structure and electronic properties of monolayer C_(4)N_(4)
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作者 陈昊 徐瑛 +1 位作者 赵家石 周丹 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期595-600,共6页
The first-principles calculations are performed to examine structural,mechanical,and electronic properties at large strain for a monolayer C_(4)N_(4),which has been predicted as an anchoring promising material to atte... The first-principles calculations are performed to examine structural,mechanical,and electronic properties at large strain for a monolayer C_(4)N_(4),which has been predicted as an anchoring promising material to attenuate shuttle effect in Li–S batteries stemming from its large absorption energy and low diffusion energy barrier.Our results show that the ideal strengths of C_(4)N_(4)under tension and pure shear deformation conditions reach 13.9 GPa and 12.5 GPa when the strains are 0.07 and 0.28,respectively.The folded five-membered rings and diverse bonding modes between carbon and nitrogen atoms enhance the ability to resist plastic deformation of C_(4)N_(4).The orderly bond-rearranging behaviors under the weak tensile loading path along the[100]direction cause the impressive semiconductor–metal transition and inverse semiconductor–metal transition.The present results enrich the knowledge of the structure and electronic properties of C_(4)N_(4)under deformations and shed light on exploring other two-dimensional materials under diverse loading conditions. 展开更多
关键词 two-dimensional materials strain effect structural evolution electronic properties
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Electronic structure and effective mass of pristine and Cl-doped CsPbBr_(3)
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作者 魏志远 魏愉昊 +7 位作者 徐申东 彭舒婷 Makoto Hashimoto 路东辉 潘旭 匡泯泉 肖正国 何俊峰 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期167-171,共5页
Organic–inorganic lead halide perovskites(LHPs) have attracted great interest owing to their outstanding optoelectronic properties.Typically,the underlying electronic structure would determinate the physical properti... Organic–inorganic lead halide perovskites(LHPs) have attracted great interest owing to their outstanding optoelectronic properties.Typically,the underlying electronic structure would determinate the physical properties of materials.But as for now,limited studies have been done to reveal the underlying electronic structure of this material system,comparing to the huge amount of investigations on the material synthesis.The effective mass of the valance band is one of the most important physical parameters which plays a dominant role in charge transport and photovoltaic phenomena.In pristine CsPbBr_(3),the Fr?hlich polarons associated with the Pb–Br stretching modes are proposed to be responsible for the effective mass renormalization.In this regard,it would be very interesting to explore the electronic structure in doped LHPs.Here,we report high-resolution angle-resolved photoemission spectroscopy(ARPES) studies on both pristine and Cl-doped CsPbBr_(3).The experimental band dispersions are extracted from ARPES spectra along both ■ and ■ high symmetry directions.DFT calculations are performed and directly compared with the ARPES data.Our results have revealed the band structure of Cl-doped CsPbBr_(3) for the first time,which have also unveiled the effective mass renormalization in the Cl-doped CsPbBr_(3) compound.Doping dependent measurements indicate that the chlorine doping could moderately tune the renormalization strength.These results will help understand the physical properties of LHPs as a function of doping. 展开更多
关键词 lead halide perovskites electronic structure effective mass
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Regulation effect of the grille spacing of a funnel-type grating water–sediment separation structure on the debris flow performance
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作者 LI Shuai GU Tianfeng +2 位作者 WANG Jiading WANG Fei LI Pu 《Journal of Mountain Science》 SCIE CSCD 2024年第7期2283-2304,共22页
The size of pores or the grille spacing of water–sediment separation structures directly affects their regulation effect on the debris flow performance.A suitable pore size or grille spacing can effectively improve t... The size of pores or the grille spacing of water–sediment separation structures directly affects their regulation effect on the debris flow performance.A suitable pore size or grille spacing can effectively improve the water–sediment separation ability of the structure.The new funnel-type grating water–sediment separation structure(FGWSS)combines vertical and horizontal structures and provides a satisfactory water–sediment separation effect.However,the regulation effect of the grille spacing of the structure on the debris flow performance has not been studied.The regulation effect of the structure grille spacing on the debris flow performance is studied through a flume test,and the optimal structure grille spacing is obtained.An empirical equation of the relationship between the relative grille spacing of the structure and the sediment separation rate is established.Finally,the influence of the water–sediment separation structure on the regulation effect of debris flows is examined from two aspects:external factors(properties of debris flows)and internal factors(structural factors).The experimental results show that the gradation characteristics of solid particles in debris flows constitute a key factor affecting the regulation effect of the structure on the debris flow performance.The optimum grille spacing of the FGWSS matches the particle size corresponding to the material distribution curves d85~d90 of the debris flow.The total separation rate of debris flow particles is related to the grille spacing of the structure and the content of coarse and fine particles in the debris flow. 展开更多
关键词 Debris flow Water–sediment separation structure Grille spacing Performance regulation effect
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Structural optimization of a reusable seismic frame active link
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作者 Károly Jármai Maryam Hasanali Kaveh Andisheh 《China Welding》 CAS 2024年第3期1-7,共7页
Circular design encompasses the use of inventive construction methodologies that possess the capability to be readily dismantled,repurposed,or recycled upon reaching the conclusion of their functional lifespan.This wo... Circular design encompasses the use of inventive construction methodologies that possess the capability to be readily dismantled,repurposed,or recycled upon reaching the conclusion of their functional lifespan.This work specifically examines the creation of a reusable design case-study idea for seismic frame design,which is commonly employed in steel-frame constructions in New Zealand.A reusable optimized design for the full seismic frame was proposed in the research.Optimizing the dimensions of welded structures,whether in terms of weight or cost,leads to a decrease in the weight of the steel utilized.The decrease in weight is directly associated with a decrease in environ-mental impact,as the environmental impact is directly proportional to the mass of the construction.The environmental consequences associated with welding technique are contingent upon the dimensions of the weld,hence exerting an indirect influence on the overall mass of the structure.Given the presence of mass dependence in all three areas,albeit in distinct manners,this work employed a multi-objective function optimization strategy to simultaneously address these areas while also partially evaluating them separately.On this way substantial reductions can be achieved both at structural mass and environmental effects. 展开更多
关键词 welded frame design structural optimization environmental effects cost calculations
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Analysis of the Application Effect of Structured Healthcare Education in Brittle Diabetic Patients
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作者 Na Deng 《Journal of Contemporary Educational Research》 2024年第6期44-49,共6页
Objective:To explore the application effect of structured healthcare education in patients with brittle diabetes mellitus.Methods:188 brittle diabetic patients admitted to our hospital from May 2021 to December 2023 w... Objective:To explore the application effect of structured healthcare education in patients with brittle diabetes mellitus.Methods:188 brittle diabetic patients admitted to our hospital from May 2021 to December 2023 were selected as the study subjects,and were divided into the control group(n=94)and the observation group(n=94)according to the random number table method.The control group used conventional nursing intervention and the observation group used structured healthcare education.The general information,glycemic indexes,self-efficacy,compliance,and nursing satisfaction of patients in the two groups were observed.Results:There was no statistical significance in the basic information of the two groups of patients(P>0.05);after the intervention,the fasting plasma glucose,2-hour postprandial blood glucose,and HbA1c of the patients in the observation group were lower than those of the control group(P<0.001);after the intervention,the self-efficacy scores of the patients in the two groups increased,and the scores of the observation group were significantly higher than those of the control group(P<0.001);the total adherence rate of the patients in the observation group(90/95.75%)was significantly higher than that of the control group(80/90.10%)(χ^(2)=6.144,P<0.05);and the total satisfaction rate of patients in the observation group(92/97.87%)was significantly higher than that of the control group(78/82.98%)(χ^(2)=12.042,P<0.05).Conclusion:In patients with brittle diabetes mellitus,structured healthcare education can effectively control patients’blood glucose levels,improve patients’self-efficacy and adherence,and enhance patient satisfaction. 展开更多
关键词 structured healthcare education Brittle diabetes mellitus Application effect
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Influence of Wind Turbine Structural Parameters on Wind Shear and Tower Shadow Effect
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作者 Yajing Zhang Chaoyang Song Zhiguo Li 《Energy Engineering》 EI 2023年第2期501-510,共10页
To overcome the problems of natural decreases in power quality,and to eliminate wind speed fluctuation due to wind shear and tower shadow effect arising from wind turbine structural parameters,an improved prediction m... To overcome the problems of natural decreases in power quality,and to eliminate wind speed fluctuation due to wind shear and tower shadow effect arising from wind turbine structural parameters,an improved prediction model accounting for the dual effect of wind shear and tower shadow is,in this paper,built.Compared to the conventional prediction model,the proposed model contains a new constraint condition,which makes the disturbance term caused by the tower shadow effect always negative so that the prediction result is closer to the actual situation.Furthermore,wind turbine structural parameters such as hub height,rotor diameter,the diameter of the tower top,and rotor overhang on wind shear and tower shadow effect are also explored in detail.The results show that the wind shear effect became weaker with the increase in hub height.The hub height is independent of the tower shadow effect.The rotor diameter is positively correlated with the wind shear and tower shadow effect.The tower shadow effect is positively correlated with the diameter of the tower top and negatively correlated with the rotor overhang. 展开更多
关键词 Wind turbine wind shear tower shadow effect dual effect structural parameters
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Ab initio study of chemical effect on structural properties of Ti–Al melts
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作者 冯运 冯艳 彭海龙 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第10期556-560,共5页
We study chemical effect on the structural properties of Ti–Al melts, with the Al concentration systematically changed,via ab initio molecular dynamics simulations. By calculating the partial coordination numbers, we... We study chemical effect on the structural properties of Ti–Al melts, with the Al concentration systematically changed,via ab initio molecular dynamics simulations. By calculating the partial coordination numbers, we find a preferred connection between the nearest neighbors for Al–Ti pairs. This induces an excess Ti coordination in the cluster characterized by local five-fold symmetry in Voronoi tessellation. Structural entropy measured from the diversity of Voronoi polyhedrons shows an intriguing non-monotonic tendency with concentration: it first decreases to a minimum value at Ti_(40)Al_(60), and then increases beyond this concentration. This implies a more ordered local structure induced by the chemical interaction at the intermediate compositions. The spatial correlation among the crystalline-like or the icosahedral-like clusters also exhibits the highest intensity for Al–Ti pairs, verifying the important role played by the chemical interaction in the local structure connectivity. 展开更多
关键词 Ti–Al alloys chemical effect atomic structure ab initio simulations
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Mechanisms Influencing Learning Gains Under Information Security: Structural Equation Modeling with Mediating Effect
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作者 Teng Zong Fengsi Wang +1 位作者 Xin Wei Yibo Liu 《Intelligent Automation & Soft Computing》 SCIE 2023年第6期3447-3468,共22页
With the expanding enrollments in higher education,the quality of col-lege education and the learning gains of students have attracted much attention.It is important to study the influencing factors and mechanisms of ... With the expanding enrollments in higher education,the quality of col-lege education and the learning gains of students have attracted much attention.It is important to study the influencing factors and mechanisms of individual stu-dents’acquisition of learning gains to improve the quality of talent cultivation in colleges.However,in the context of information security,the original data of learning situation surveys in various universities involve the security of educa-tional evaluation data and daily privacy of teachers and students.To protect the original data,data feature mining and correlation analyses were performed at the model level.This study selected 12,181 pieces of data from X University,which participated in the Chinese College Student Survey(CCSS)from 2018 to 2021.A confirmatory factor analysis was conducted and a structural equation modeling was conducted using AMOS 24.0.Through hypothesis testing,this study explored the mechanisms that influence learning gains from the per-spectives of student involvement,teacher involvement,and school support.The results indicated that the quality of student involvement has an important mediat-ing effect on learning gains and that a supportive campus environment has the greatest influence on learning gains.Establishing positive emotional communica-tions between teachers and students is a more direct and effective method than improving the teaching level to improve the quality of student involvement.This study discusses the implications of these results on the research and practice of connotative development in higher education. 展开更多
关键词 structural equation model mediating effect chinese college student survey learning gains
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Element doping induced microstructural engineering enhancing the lithium storage performance of high-nickel layered cathodes 被引量:2
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作者 Zhizhan Li Xiao Huang +4 位作者 Jianing Liang Jinlei Qin Rui Wang Jinguo Cheng Deli Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第2期461-468,I0012,共9页
The high-nickel layered cathodes Li[Ni_(x)Co_(y)Mn_(1-x-y)]O_(2)(x≥0.8)with high specific capacity and long cycle life are considered as prospective cathodes for lithium-ion batteries.However,the microcrack formation... The high-nickel layered cathodes Li[Ni_(x)Co_(y)Mn_(1-x-y)]O_(2)(x≥0.8)with high specific capacity and long cycle life are considered as prospective cathodes for lithium-ion batteries.However,the microcrack formation and poor structural stability give rise to inferior rate performance and undesirable cycling life.Herein,we propose a dual modification strategy combining primary particle structure design and element doping to modify Li[Ni_(0.95)Co_(0.025)Mn_(0.025)]O_(2) cathode by tungsten and fluorine co-doped(W-F-NCM95).The doping of W can convert the microstructure of primary particles to the unique rod-like shape,which is beneficial to enhance the reversibility of phase transition and alleviate the generation of microcracks.F doping is conducive to alleviating the surface side reactions.Thus,due to the synergistic effect of W,F codoping,the obtained W-F-NCM95 cathodes deliver a high initial capacity of 236.1 mA h g^(-1) at 0.1 C and superior capacity retention of 88.7%over 100 cycles at 0.5 C.Moreover,the capacity still maintains73.8%after 500 cycles at 0.5 C and the texture of primary particle is intact.This work provides an available strategy by W and F co-doping to enhance the electrochemistry performance of high-nickel cathodes for practical application. 展开更多
关键词 High-nickel cathodes Multi-strategy Cation-anion co-doping Particle structure design Synergistic effect
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A hierarchically structured tin-cobalt composite with an enhanced electronic effect for high-performance CO_(2) electroreduction in a wide potential range 被引量:2
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作者 Xingxing Jiang Xuan Li +5 位作者 Yan Kong Chen Deng Xiaojie Li Qi Hu Hengpan Yang Chuanxin He 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第1期462-469,I0012,共9页
Earth-abundant and nontoxic Sn-based materials have been regarded as promising catalysts for the electrochemical conversion of CO_(2)to C1 products,e.g.,CO and formate.However,it is still difficult for Snbased materia... Earth-abundant and nontoxic Sn-based materials have been regarded as promising catalysts for the electrochemical conversion of CO_(2)to C1 products,e.g.,CO and formate.However,it is still difficult for Snbased materials to obtain satisfactory performance at low-to-moderate overpotentials.Herein,a simple and facile electrospinning technique is utilized to prepare a composite of a bimetallic Sn-Co oxide/carbon matrix with a hollow nanotube structure(Sn Co-HNT).Sn Co-HNT can maintain>90%faradaic efficiencies for C1 products within a wide potential range from-0.6 VRHE to-1.2 VRHE,and a highest 94.1%selectivity towards CO in an H-type cell.Moreover,a 91.2%faradaic efficiency with a 241.3 m A cm^(-2)partial current density for C1 products could be achieved using a flow cell.According to theoretical calculations,the fusing of Sn/Co oxides on the carbon matrix accelerates electron transfer at the atomic level,causing electron deficiency of Sn centers and reversible variation between Co^(2+)and Co^(3+)centers.The synergistic effect of the Sn/Co composition improves the electron affinity of the catalyst surface,which is conducive to the adsorption and stabilization of key intermediates and eventually increases the catalytic activity in CO_(2)electroreduction.This study could provide a new strategy for the construction of oxide-derived catalysts for CO_(2)electroreduction. 展开更多
关键词 Hierarchic structure Tin-cobalt bimetallic oxide Electronic effect CO_(2)electroreduction Wide potential range
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The Maximum Effective Moment Criterion (MEMC) and Its Implications in Structural Geology 被引量:15
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作者 ZHENG Yadong WANG Tao WANG Xinshe 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2006年第1期70-78,共9页
The MohroCoulomb criterion has been widely used to explain formation of fractures. However, it fails to explain large strain deformation that widely occurs in nature. There is presently a new theory, the MEMC, which i... The MohroCoulomb criterion has been widely used to explain formation of fractures. However, it fails to explain large strain deformation that widely occurs in nature. There is presently a new theory, the MEMC, which is mathematically expressed as Meff = ((σ1-σ3) L.sin 2α sin α)/2, where σ1-σ3 represents the yield strength of the related rock, L is a unit length and a is the angle between σ1 and deformation bands. This criterion demonstrates that the maximum value appears at angles of ±54.7° to σ1 and there is a slight difference in the moment in the range of 55°±10°. The range covers the whole observations available from nature and experiments. Its major implications include: (1) it can be used to determine the stress state when the related deformation features formed; (2) it provides a new approach to determine the Wk of the related ductile shear zone if only the ratio of the vorticity and strain rate remains fixed; (3) It can be used to explain (a) the obtuse angle in the contraction direction of conjugate kink-bands and extensional crenulation cleavages, (b) formation of low-angle normal faults and high-angle reverse faults, (c) lozenge ductile shear zones in basement terranes, (d) some crocodile structures in seismic profiles and (e) detachment folds in foreland basins. 展开更多
关键词 maximum effective moment criterion crenulation cleavage low-angle normal fault high-angle reverse fault crocodile structure lozenge structure detachment fold
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Impact of effective stress on permeability for carbonate fractured-vuggy rocks 被引量:1
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作者 Ke Sun Huiqing Liu +5 位作者 Juliana Y.Leung Jing Wang Yabin Feng Renjie Liu Zhijiang Kang Yun Zhang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第3期942-960,共19页
To gain insight into the flow mechanisms and stress sensitivity for fractured-vuggy reservoirs,several core models with different structural characteristics were designed and fabricated to investigate the impact of ef... To gain insight into the flow mechanisms and stress sensitivity for fractured-vuggy reservoirs,several core models with different structural characteristics were designed and fabricated to investigate the impact of effective stress on permeability for carbonate fractured-vuggy rocks(CFVR).It shows that the permeability performance curves under different pore and confining pressures(i.e.altered stress conditions)for the fractured core models and the vuggy core models have similar change patterns.The ranges of permeability variation are significantly wider at high pore pressures,indicating that permeability reduction is the most significant during the early stage of development for fractured-vuggy reservoirs.Since each obtained effective stress coefficient for permeability(ESCP)varies with the changes in confining pressure and pore pressure,the effective stresses for permeability of four representative CFVR show obvious nonlinear characteristics,and the variation ranges of ESCP are all between 0 and 1.Meanwhile,a comprehensive ESCP mathematical model considering triple media,including matrix pores,fractures,and dissolved vugs,was proposed.It is proved theoretically that the ESCP of CFVR generally varies between 0 and 1.Additionally,the regression results showed that the power model ranked highest among the four empirical models mainly applied in stress sensitivity characterization,followed by the logarithmic model,exponential model,and binomial model.The concept of“permeability decline rate”was introduced to better evaluate the stress sensitivity performance for CFVR,in which the one-fracture rock is the strongest,followed by the fracture-vug rock and two-horizontalfracture rock;the through-hole rock is the weakest.In general,this study provides a theoretical basis to guide the design of development and adjustment programs for carbonate fractured-vuggy reservoirs. 展开更多
关键词 effective stress PERMEABILITY Carbonate fractured-vuggy rocks structure characteristics Stress sensitivity
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Coherence of the Even-Odd Rule with an Effective-Valence Isoelectronicity Rule for Chemical Structural Formulas: Application to Known and Unknown Single-Covalent-Bonded Compounds 被引量:5
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作者 Geoffroy Auvert 《Open Journal of Physical Chemistry》 2014年第3期126-133,共8页
Ions or molecules are said to be isoelectronic if they are composed of different elements but have the same number of electrons, the same number of covalent bonds and the same structure. This criterion is unfortunatel... Ions or molecules are said to be isoelectronic if they are composed of different elements but have the same number of electrons, the same number of covalent bonds and the same structure. This criterion is unfortunately not sufficient to ensure that a chemical structure is a valid chemical compound. In a previous article, a procedure has been described to draw 2D valid structural formulas: the even-odd rule. This rule has been applied first to single-bonded molecules then to single-charged single-bonded ions. It covers hypovalent, hypervalent or classic Lewis’ octet compounds. The funding principle of the even-odd rule is that each atom of the compound possesses an outer-shell filled only with pairs of electrons. The application of this rule guarantees validity of any single-covalent-bond chemical structure. In the present paper, this even-odd rule and its electron-pair criterion are checked for coherence with an effective-valence isoelectronic rule using numerous known compounds having single-covalent-bond connections. The test addresses Lewis’ octet ions or molecules as well as hypovalent and hypervalent compounds. The article concludes that the even-odd rule and the effective-valence isoelectronicity rule are coherent for known single-covalent-bond chemical compounds. 展开更多
关键词 Isoelectronicity effectIVE VALENCE MOLECULE Ion Even-Odd RULE structural Formula COVALENT Bond
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Purification,structural elucidation,and in vitro antitumor effects of novel polysaccharides from Bangia fuscopurpurea 被引量:6
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作者 Jingna Wu Xiaoting Chen +2 位作者 Kun Qiao Yongchang Su Zhiyu Liu 《Food Science and Human Wellness》 SCIE 2021年第1期63-71,共9页
A water-soluble polysaccharide,designated BFP-3,was isolated from Bangia fuscopurpurea by hot water extraction,anion-exchange,and size-exclusion chromatography and tested to determine its antitumor activity.The struct... A water-soluble polysaccharide,designated BFP-3,was isolated from Bangia fuscopurpurea by hot water extraction,anion-exchange,and size-exclusion chromatography and tested to determine its antitumor activity.The structural characteristics of BFP-3 were investigated by chemical and spectroscopic methods,including partial acid hydrolysis,methylation analysis,one-and two-dimensional nuclear magnetic resonance,and gas chromatography-mass spectrometry.The results showed that BFP-3 was mainly comprised of rhamnose,arabinose,mannose,glucose,and galactose.Moreover,the weight-average molecular weight of BFP-3 was estimated to be approximately 333 kDa.The backbone of BFP-3 was primarily composed of repeating 5-α-l-Araf-1→(4-α-d-Glcp-1)_(4)→4,6-β-d-Manp-1 units,and the side chains consisted of repeatingβ-d-Galp-1→(4-β-d-Galp-1)_(4)→4,6-β-d-Galp-1→3,4-α-l-Rhap,β-l-Arap-1→(3-β-d-Galp-1)_(3),andβ-l-Arap-1 units.Counting Kit-8 assays revealed that BFP-3 significantly inhibited the proliferation of A2780,COC1,SKOV3,HO-8910,and OVCAR3 ovarian cancer cells in vitro,indicating that BFP-3 could have potential applications in the treatment of ovarian cancer. 展开更多
关键词 Bangia fuscopurpurea POLYSACCHARIDE structure ovarian cancer Antitumor effect
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Influence of social capital on farmer household income gap:total effect and structural effect 被引量:1
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作者 Geling Wang Qian Lu 《Chinese Journal of Population,Resources and Environment》 2016年第1期30-37,共8页
Based on the survey data of typical villages in Shaanxi Province,China,the effect of social capital on the income gap of farmers' households was analyzed using the Shapley value of the total amount of social capit... Based on the survey data of typical villages in Shaanxi Province,China,the effect of social capital on the income gap of farmers' households was analyzed using the Shapley value of the total amount of social capital and the social capital structure.The results show the following:first,social capital can expand the household income gap,and the effect of this index on the household income gap is 7.54%.Second,the indexes of the social capital dimension can expand the household income gap,and the structural effects of the household income gap on social networks,social trust,and social participation are 3.17%,3.64%,and 0.65%,respectively.Third,no dimension of the path is the same as the effect on the household income gap. 展开更多
关键词 Income gap social capital structural effect total effect
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Synthesis, Structural Characterization and Magnetocaloric Effect of a Butterfly [CoⅡ2GdⅢ2] Cluster 被引量:1
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作者 LIU Tong HUANG Yuan-Mei +2 位作者 ZOU Hua-Hong WANG Hai-Ling LIANG Fu-Pei 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2019年第7期1152-1158,共7页
2-(2,3-Dihydroxpropyliminomethyl)6-methoxyphenol(H3L), trimethylacetic acid(Hpiv), Gd(NO3)3·6 H2O and Co(NO3)2·6 H2O were reacted in Me OH to obtain a heterometallic tetranuclear cluster [Gd2Co2(L... 2-(2,3-Dihydroxpropyliminomethyl)6-methoxyphenol(H3L), trimethylacetic acid(Hpiv), Gd(NO3)3·6 H2O and Co(NO3)2·6 H2O were reacted in Me OH to obtain a heterometallic tetranuclear cluster [Gd2Co2(L)2(μ3-OH)2(piv)6]·2 Hpiv·2 CH3OH(1). X-ray crystallographic analysis reveals that compound 1 was found to be a butterfly heterometallic tetranuclear cluster. The crystal(C64H108Co2Gd2N2O28, Mr = 1785.88) belongs to the triclinic crystal system, space group P1 with a =11.9798(6), b = 12.0877(5), c = 15.0367(7) ?, α = 67.320(4)°, β = 81.583(4)°, γ = 75.201(4)°, V =1939.62(18) ?3, Z = 1, T = 293.15 K, R = 0.048 and w R = 0.144 for 16299 observed reflections with I > 2σ(I). In magnetization study, heterometallic 1 exhibits magnetocaloric effect(MCE) of 14.75 J·kg-1·K-1 at 2 K for ΔH = 5 T, while it does not show non-linear response of the ac-susceptibilities. 展开更多
关键词 TETRANUCLEAR CLUSTER HETEROMETALLIC crystal structure MAGNETOCALORIC effect
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Structure and material study of dielectric laser accelerators based on the inverse Cherenkov effect
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作者 孙斌 何阳帆 +5 位作者 罗若云 章太阳 周强 王少义 王度 赵宗清 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第9期250-254,共5页
Dielectric laser accelerators(DLAs)are considered promising candidates for on-chip particle accelerators that can achieve high acceleration gradients.This study explores various combinations of dielectric materials an... Dielectric laser accelerators(DLAs)are considered promising candidates for on-chip particle accelerators that can achieve high acceleration gradients.This study explores various combinations of dielectric materials and accelerated structures based on the inverse Cherenkov effect.The designs utilize conventional processing methods and laser parameters currently in use.We optimize the structural model to enhance the gradient of acceleration and the electron energy gain.To achieve higher acceleration gradients and energy gains,the selection of materials and structures should be based on the initial electron energy.Furthermore,we observed that the variation of the acceleration gradient of the material is different at different initial electron energies.These findings suggest that on-chip accelerators are feasible with the help of these structures and materials. 展开更多
关键词 dielectric laser accelerator high gradient accelerator inverse Cherenkov effect accelerated structure and material
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