Fracture surface contour study is one of the important requirements for characterization and evaluation of the microstructure of rocks.Based on the improved cube covering method and the 3D contour digital reconstructi...Fracture surface contour study is one of the important requirements for characterization and evaluation of the microstructure of rocks.Based on the improved cube covering method and the 3D contour digital reconstruction model,this study proposes a quantitative microstructure characterization method combining the roughness evaluation index and the 3D fractal dimension to study the change rule of the fracture surface morphology after blasting.This method was applied and validated in the study of the fracture microstructure of the rock after blasting.The results show that the fracture morphology characteristics of the 3D contour digital reconstruction model have good correlation with the changes of the blasting action.The undulation rate of the three-dimensional surface profile of the rock is more prone to dramatic rise and dramatic fall morphology.In terms of tilting trend,the tilting direction also shows gradual disorder,with the tilting angle increasing correspondingly.All the roughness evaluation indexes of the rock fissure surface after blasting show a linear and gradually increasing trend as the distance to the bursting center increases;the difference between the two-dimensional roughness evaluation indexes and the three-dimensional ones of the same micro-area rock samples also becomes increasingly larger,among which the three-dimensional fissure roughness coefficient JRC and the surface roughness ratio Rs display better correlation.Compared with the linear fitting formula of the power function relationship,the three-dimensional fractal dimension of the postblast fissure surface is fitted with the values of JRC and Rs,which renders higher correlation coefficients,and the degree of linear fitting of JRC to the three-dimensional fractal dimension is higher.The fractal characteristics of the blast-affected region form a unity with the three-dimensional roughness evaluation of the fissure surface.展开更多
BACKGROUND:Three-dimensional diffusion tensor tract(DTT)is the newest imaging to describe the structure of white matter fiber in three-dimensions,it has great significance in dividing the concrete anatomic site of gra...BACKGROUND:Three-dimensional diffusion tensor tract(DTT)is the newest imaging to describe the structure of white matter fiber in three-dimensions,it has great significance in dividing the concrete anatomic site of gray and white matter lesions,displaying the correlation with fibrous band and judging clinical prognosis,which is incomparable by other imagings.OBJECTIVE:To observe the conditions of corticospinal tract(CST)in acute cerebral ischemic stroke patients,and analyze the relationship between motor function and the severity of CST injury.DESIGN:A case-control observation.SETTING:Department of Medical Imaging,Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA.PARTICIPANTS:Fifteen patients with acute cerebral infarction were selected from Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA from February to December in 2005.They all suffered from acute attack and motor disorder of hemiplegic limbs to different extent,and were conformed by CT or MRI.There were 9 males and 6 females,aging 16-87 years old,the median age was 51.7 years,and all were right handed.Fifteen right-handed normal subjects,who were matched by age and sex with the patients in the cerebral infarction group,were selected from the relatives of patients and physicians of the Imaging Department as the control group.All the subjects were informed and agreed with the study.METHODS:The patients with acute cerebral infarction and subjects in the control group received MR diffusion tensor imaging(DTI)with GE 1.5 T nuclear magnetic resonance system,fiber tracking with the software of dTV-Ⅱ.Fractional anisotropy(FA)maps and three-dimensional tractography of bilateral CST of all patients were created.Displacement,continuity and destroy of fibrous bands were observed.At the same time,muscle strength of ipsilateral hand of patients with cerebral infarction was measured with Brunnstrom standard.The correlation between the severity of CST injury and the muscle strength of ipsilateral hand was analyzed with spearman correlation analysis.MAIN OUTCOME MEASURES:①FA values in the infarcted sites and those in the contralateral corresponding sites of patients with cerebral infarction;②CST manifestations in the patients with cerebral infarction and the control group.RESULTS:All the 30 testees were involved in the analysis of results.①The FA values in infarcted sites of white matter were significantly lower than those in the contralateral ones(t=4.570,P<0.001).②In the control group,bilateral CST were reconstructed,they originated from precentral gyrus,went downwards to internal capsule,and extended to pontine and medulla oblongata,each fiber had good uniformity in continuous form.In the patients with cerebral infarction,the forms of contralateral CST were consistent with those in the control group with good continuity.Due to the involvement by the infarcted site to different extents,the ipsilateral CST manifested as continuous interruption and loss of uniformity in anatomic structure and form.The CST involvements were divided into three grades:integrated CST for grade 1(n=2);integrated CST but compressed or displaced for grade 2(n=5);interrupted CST for grade 3(n=8).③The severity of CST injury was obviously correlated with the muscle strength of the ipsilateral hand(r=0.888,P<0.05).CONCLUSION:①CST is injured to different extents in patients with acute cerebral infarction,and the severity of injury is associated with muscle strength.It is indicated that it can be used to judge the prognosis of rehabilitative treatment.②DTT can directly display the status of pyramidal tract more three-dimensionally.展开更多
As natural ecosystems provide the material basis and fundamental support for regional sustainable devel-opment,the sustainability of natural ecosystems is an important prerequisite and a viable approach for the achiev...As natural ecosystems provide the material basis and fundamental support for regional sustainable devel-opment,the sustainability of natural ecosystems is an important prerequisite and a viable approach for the achievement of regional sustainable development.It is also the final criteria to assess whether sustainable development paradigm is successful.Along with the increasing impacts of human activities on natural ecosystems,the evaluation of regional ecological sustainability has become one of the key issues for research on macro ecology and sustainable development.Based on different unit of indicators,this study firstly groups the evaluation frameworks of regional ecological sus-tainability into three major types:comprehensive index evaluation with dimensionless unit,monetary valuation,and biophysical quantity measurement.We then discuss and compare these types in terms of basic principles,scope of ap-plications,advantages and shortcomings.Finally,drawn on the discussion about characteristics of ecological sustain-ability,we outline the current trend and future directions of regional ecological sustainability evaluation,for instance,transition from sustainable development evaluation to sustainability science,integration of goal-oriented and problem-solving approaches,combination of spatial pattern analysis and ecological sustainability evaluation,and en-hancement of ecological sustainability evaluation at landscape scale.展开更多
Two reported three-dimensional covalent organic frameworks(3D-COFs),COF-300 and COF-301,which have hierarchical porous structures and large pore volumes,were synthesized and employed as host materials for lithium-sulf...Two reported three-dimensional covalent organic frameworks(3D-COFs),COF-300 and COF-301,which have hierarchical porous structures and large pore volumes,were synthesized and employed as host materials for lithium-sulfur batteries.Owing to possessing excellent porosities as well as abundant hydroxyl groups in the pore walls,COF-301 can not only trap lithium polysulfides(PSs)via physical adsorption inside the pores,but also capture PSs by chemical interactions to relieve the shuttle effect.Interestingly,it is the first time that 3D-COFs were utilized as host materials for lithium-sulfur batteries as well as hydroxyl groups were introduced into COFs for improving the battery performance.As a result,COF-301@S as cathode material could reserve the capacity of 411.6 mA·h·g^-1 after 500 cycles with only 0.081%fading per cycle at 0.5 C,exhibiting better battery performance compared with COF-300@S.This study not only expands the applications of 3D-COFs but also provides a new route for designing lithium-sulfur batteries.展开更多
Global warming and rapid economic development have led to increased levels of disaster risk in China.Previous attempts at assessing drought risk were highly subjective in terms of assessment methods and selection of t...Global warming and rapid economic development have led to increased levels of disaster risk in China.Previous attempts at assessing drought risk were highly subjective in terms of assessment methods and selection of the assessment indicators and which resulted in appreciable uncertainty in the results of these risk assessments.Based on the assumption that areas with historically high drought losses are more likely to suffer future high drought losses,we develop a new drought risk assessment model that includes historical drought loss data.With this model,we map the regional differentiation of Chinese drought risk.Regions with high(extreme high)drought risk account for 4.3%of China’s area.Five significant high-risk areas have been identified:Northeast China,North China,the east part of Northwest China,the east part of Southwest China and a small part in the west of Northwest China.Areas with high and extreme high drought risk are dominant in the Heilongjiang Province,accounting for 32%of the total area,followed by the Ningxia Hui Autonomous Region,with 26%of total area.The contribution of each influencing factor has been quantified,which indicates that high-exposure and high-vulnerability account for the high-risk of drought.We recommend that measures like strengthening the protection of cultivated land and reducing dependence on the primary industry should be taken to mitigate to drought-induced losses.展开更多
The bis(tributyltin) ester of succinic acid was synthesized by the reaction of disodium salt of succinic acid with tributyltin chloride in a molar ratio of 1:2. The crystal structure was determined by X-ray single-cry...The bis(tributyltin) ester of succinic acid was synthesized by the reaction of disodium salt of succinic acid with tributyltin chloride in a molar ratio of 1:2. The crystal structure was determined by X-ray single-crystal diffraction. It belongs to orthorhombic with space group Pccn, a = 20.949(3), b = 17.470(3), c = 20.345(3) Angstrom, V = 7446(2) Angstrom(3), Z = 8, D-c = 1.242 g/cm(3), mu = 1.365 mm(-1), F(000) = 2864, R = 0.0544 and wR = 0.1417. The tin atom is of five-coordination in a trigonal bipyramidal structure by bridging two carboxylate groups in different directions and the resulting structure which contains straight twist large ring channels along the axes of a, b and c is a three-dimensional framework polymer containing two different tin atoms.展开更多
The harmful algal bloom primarily caused by Microcystis aeruginosa(M.aeruginosa)has become one of the serious biological pollution issues in actual water,which has received intense attention worldwide.Over the past ye...The harmful algal bloom primarily caused by Microcystis aeruginosa(M.aeruginosa)has become one of the serious biological pollution issues in actual water,which has received intense attention worldwide.Over the past years,increasing number of publications have reported that metal-organic frameworks(MOFs)based functional materials exhibited significant inhibition against M.aeruginosa via multiple mechanisms,but no review papers systematically presented progresses regarding MOFs-based materials for M.aeruginosa control up to now.With this review paper,we summarized the state-of-the-art studies of MOFsbased materials for M.aeruginosa removal,comparing and discussing the design strategies of MOFs-based materials and their antimicrobial mechanisms.Meanwhile,we discussed methods for evaluating the water purification performances of MOFs-based materials against M.aeruginosa.Finally,the perspectives for design of novel MOFs-based functional materials and application scenarios were proposed to provide an outlook on areas where greater efforts should be made in the future.展开更多
With the intensi fed impact of human activities,most lakes have been severely disturbed and the lake ecosystem has been seriously damaged,which exerted a great impact on the living envi-ronment of human beings in the ...With the intensi fed impact of human activities,most lakes have been severely disturbed and the lake ecosystem has been seriously damaged,which exerted a great impact on the living envi-ronment of human beings in the lake basins.The health of the lake ecosystem has gradually become one of the hot issues in recent years.In this study,the water resources carrying capacity(WRCC)was used to reveal the chain rel ationship between human activities and water environ-ment in the economic dewelopment of the Dianchi Lake Basin in Kunming City of China during 2005-2015.Specifically,we chose 25 ewaluation indicators related to the water environment and socialeconomic activities,classified them into six subsystems,Le,the driwing force subsystem(D),the water resources si tuation and consumption subsystem(S),the water resources pressure subsystem(P),the water environmental situation subsystem(E),the response subsystem(R),and the management subsystem(M),and built a comprehensive assessment system-DSPERM frame-work model.Si mulated annealing-projection pursuit model which reflects the structure or feature of high-dimensional data was adopted to calculate the WRCC of the Dianchi Lake Basin during 2005-2015 by weighting each evaluation indicator and each subsystem of the DSPERM frame work model.The resuls show that the WRCC of the Dlanchi Lake Basin was in level II(medium carying capacity)from 2005 to 2012.Since 2013,the WRCC has been at level II(strong carying capacity),and from 2005 to 2015,it showed a gradual upward trend.The evaluation indicators of each subsystem varied greatly and exhibited different development trends.The indicators of the water resources pressure subsystem had the greatest impact on the WRCC,followed by the in-dicators of the water environmental si tuation subsystem and the water resources situation and consumption subsystem.We recommend that the DSPERM framework model and the simulated anneal ing-projection pursuit model constructed in this work can be used to analyze the dynamic changes of the WRCC over the years.They have the advantages of practicability and feasibilty,and can provide the basis for the scienti fic decision-making and comprehensive management of regional water environment planning.展开更多
Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully construct...Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully constructed by coordinatively assembling the semi-rigid multidentate ligand 5-(1-carboxyethoxy)isophthalic acid(H₃CIA)with the Nheterocyclic ligands 1,4-di(4H-1,2,4-triazol-4-yl)benzene(1,4-dtb)and 1,4-di(1H-imidazol-1-yl)benzene(1,4-dib),respectively,around Co^(2+)ions.Single-crystal X-ray diffraction analysis revealed that in both complexes HU23 and HU24,the CIA^(3-)anions adopt aκ^(7)-coordination mode,bridging six Co^(2+)ions via their five carboxylate oxygen atoms and one ether oxygen atom.This linkage forms tetranuclear[Co4(μ3-OH)2]^(6+)units.These Co-oxo cluster units were interconnected by CIA^(3-)anions to assemble into 2D kgd-type structures featuring a 3,6-connected topology.The 2D layers were further connected by 1,4-dtb and 1,4-dib,resulting in 3D pillar-layered frameworks for HU23 and HU24.Notably,despite the similar configurations of 1,4-dtb and 1,4-dib,differences in their coordination spatial orientations lead to topological divergence in the 3D frameworks of HU23 and HU24.Topological analysis indicates that the frameworks of HU23 and HU24 can be simplified into a 3,10-connected net(point symbol:(4^(10).6^(3).8^(2))(4^(3))_(2))and a 3,8-connected tfz-d net(point symbol:(4^(3))_(2)((4^(6).6^(18).8^(4)))),respectively.This structural differentiation confirms the precise regulatory role of ligands on the topology of metal-organic frameworks.Moreover,the ultraviolet-visible absorption spectra confirmed that HU23 and HU24 have strong absorption capabilities for ultraviolet and visible light.According to the Kubelka-Munk method,their bandwidths were 2.15 and 2.08 eV,respectively,which are consistent with those of typical semiconductor materials.Variable-temperature magnetic susceptibility measurements(2-300 K)revealed significant antiferromagnetic coupling in both complexes,with their effective magnetic moments decreasing markedly as the temperature lowered.CCDC:2457554,HU23;2457553,HU24.展开更多
Researchers' understandings of economic, ecological and social benefits of urban green spaces were discussed from many perspectives, connotations of such three major benefits were redefined, existing problems in t...Researchers' understandings of economic, ecological and social benefits of urban green spaces were discussed from many perspectives, connotations of such three major benefits were redefined, existing problems in the present evaluation were analyzed. According to service objects of urban green spaces, 6 relationship fields were classified, specifically, global ecology, regional environment, regional health, basic life, spiritual life and material life, a basic framework for evaluating economic, ecological and social benefits of urban green spaces was proposed.展开更多
Covalent organic frameworks(COFs) are a class of crystalline porous organic materials with variable structures and fascinating properties. The intrinsic low conductivity impedes their widely application in optoelectro...Covalent organic frameworks(COFs) are a class of crystalline porous organic materials with variable structures and fascinating properties. The intrinsic low conductivity impedes their widely application in optoelectronic. Iodine doping is an effective way to enhance the electrical conductivity of COFs. Here, a novel 3D imine COF with lvt topology is synthesized from two different pentacene derivatives with the same core in the form of structural complementarity. DDHP-COF is a highly crystalline material featuring high surface area of 1679 m^(2)/g and excellent thermal stability up to 490 ℃. Upon doping with iodine, the electrical conductivity can reach as high as 1.5×10^(-2)S/m which is significantly enhanced over 6 orders of magnitude compared with the pristine COF.展开更多
A new heteropolyoxotungstate [（C2H4N2）4（P4Co3W4O28H6）（H2C2O4）]n with a three-dimensional framework was hydrothermally synthesized.The compound crystallizes in a tetragonal system,space group I41/a with a = 17.1...A new heteropolyoxotungstate [（C2H4N2）4（P4Co3W4O28H6）（H2C2O4）]n with a three-dimensional framework was hydrothermally synthesized.The compound crystallizes in a tetragonal system,space group I41/a with a = 17.1006（17）,b = 17.1006（7）,c = 10.7525（5）,V = 3144.2（2）3,Z = 4,Dc = 3.795 g·cm-3,F（000） = 3300,MoKα（λ = 0.71073 ）,μ = 16.460 mm-1,the final R = 0.0335 and wR = 0.0776.In the heteropolyoxotungstate,tungsten-oxygen octahedra are linked by sharing two cis-vertexes into an infinite helical chain extending along the c axis.Cobalt atoms in the octahedral geometry act as the linkers of these chains,forming a three-dimensional framework.The cobalt and phosphorus atoms in the tetrahedral geometry play a role in stabilizing the three-dimensional framework.Ethylenediamine molecules are polymerized into organic chains which locate in the interspaces of the framework in the way of interwinding with the W-O chains.展开更多
[Objective] The aim was to conduct post-evaluation on environmental planning by means of logical framework approach. [Method] Taking environmental planning during '11th Five-year Plan' in a certain province fo...[Objective] The aim was to conduct post-evaluation on environmental planning by means of logical framework approach. [Method] Taking environmental planning during '11th Five-year Plan' in a certain province for example, by means of logical framework approach (LFA), the post-evaluation on environmental planning was carried out from the aspects of evaluation content, index system, implementation steps, evaluation feedback and input-output analysis of environmental planning. [Result] The post-evaluation on environmental planning by means of LFA achieved expected purpose and various indexes at different stages of environmental planning was assessed, and then corresponding countermeasures were put forward according to the problems which were found by problem tree of environmental planning project. [Conclusion] The study could provide theoretical references for the post-evaluation on environmental planning in future.展开更多
This paper aims to devising an evaluation plan for an Integrated English Course within the RUFDATA framework in an attempt to illuminate the working mechanism of the Framework.
Previous mobile usability studies are only pertinent in the context of ergonomics,physical user interface,and mobility aspects.In addition,much of the previous mobile usability conception was built on desktop co...Previous mobile usability studies are only pertinent in the context of ergonomics,physical user interface,and mobility aspects.In addition,much of the previous mobile usability conception was built on desktop computing measurements,such as desktop and web application checklists,or scarcely addressed the mobile user interface.Moreover,the studies focus mainly on interface features for desktop applications and do not reflect comprehensive mobile interface features such as navigation drawers and spinners.Therefore,conducting usability evaluation using conventional usability measurement would result in irrelevant results.In addition,the resulting works are tailored for usability testing,which requires highly skilled evaluators and usability specialists(e.g.,usability testers and user experience designers),who are rarely integrated into a development team.The lack of expertise could lead to unreliable usability evaluations.This paper presents a review from industrial experts on a comprehensive and feasible usability evaluation framework developed in our previous work.The framework is dedicated to smartphone apps,which integrate evaluator skills and design concerns.However,there is no evidence of its usefulness in practice.Therefore,the usefulness of the framework measurement for evaluating apps’usability in the eyes of non-usability specialists is empirically assessed in this paper through an expert review.The expert review involved eleven industrial developers and was complemented by a semi-structured interview.The method is replicated in comparison with a framework from another study.The findings show that the formulated framework significantly outperformed the framework(p=0.0286)from other studies with large effect sizes(r=1.81)in terms of usefulness.展开更多
The evolution of the society and economy has stimulated the development of Knowledge Service(KS), making it an indispensable solution to address future challenges facing libraries and information institutions. However...The evolution of the society and economy has stimulated the development of Knowledge Service(KS), making it an indispensable solution to address future challenges facing libraries and information institutions. However at present, academic research on knowledge service is falling short and its definition is far from clear and complete. As such,this article proposes the Three-dimensional Framework Knowledge Service(TdFKS) for libraries and information institutions based on the knowledge value chain model. By making reliability analysis and mean value analysis of a questionnaire survey result, the article clarifies the structure of the three-dimensional framework and verifies the rationality of the TdFKS.展开更多
The Critical Discourse Analysis(CDA)is an interdisciplinary tool in various conditions,which aims to provide a better understanding of sociocultural aspects of texts and accounts of the production of internal structur...The Critical Discourse Analysis(CDA)is an interdisciplinary tool in various conditions,which aims to provide a better understanding of sociocultural aspects of texts and accounts of the production of internal structure,and overall organization of texts as well as to provide a critical dimension in its theoretical and descriptive accounts of texts.Since June last year,HK protests or HK violence have been frequently reported by worldwide media.In this paper,the author aims to find out how the HK protesters and the Mainland media describe the same event based on the three-dimensional framework of CDA.At last,the author concludes that the mainland media generally describe the event as violence and riot while the HK protesters define themselves as warriors striving for more freedom,justice and democracy.Besides,on this event,the Mainland media mainly accuses some western countries of interference into HK affairs,which is undoubtedly of China’s internal affairs,and the media give full support to the HK police in safeguarding the peace and stability of Hong Kong.But from the perspective of HK protesters,they firmly believe that they are using their actions to protect all the people of HK,and they are defending their values such as freedom,democracy and justice.These are two totally different systems of language,and the author also gives its potential reasons in the paper so as to offer some viewpoints in this aspect in combination with the CDA theory.展开更多
Cryosphere science research and development(R&D) has been strongly committed to public service, integrating natural sciences with socioeconomic impacts. Owing to the current shift from purely natural cryosphere sc...Cryosphere science research and development(R&D) has been strongly committed to public service, integrating natural sciences with socioeconomic impacts. Owing to the current shift from purely natural cryosphere scientific research to linking cryosphere science with socioeconomic and cultural science, cross-disciplinary research in this field is emerging, which advocates future cryosphere science research in this field. Utilizing the cryosphere service function(CSF), this study establishes CSF and its value evaluation system. Cryosphere service valuation can benefit the decisionmakers' and public's awareness of environmental protection. Implementing sustainable CSF utilization strategies and macroeconomic policymaking for global environmental protection will have profound and practical significance as well as avoid environmental degradation while pursuing short-term economic profits and achieving rapid economic development.展开更多
基金National Key Research and Development Program of China,Grant/Award Number:2021YFC2902103National Natural Science Foundation of China,Grant/Award Number:51934001Fundamental Research Funds for the Central Universities,Grant/Award Number:2023JCCXLJ02。
文摘Fracture surface contour study is one of the important requirements for characterization and evaluation of the microstructure of rocks.Based on the improved cube covering method and the 3D contour digital reconstruction model,this study proposes a quantitative microstructure characterization method combining the roughness evaluation index and the 3D fractal dimension to study the change rule of the fracture surface morphology after blasting.This method was applied and validated in the study of the fracture microstructure of the rock after blasting.The results show that the fracture morphology characteristics of the 3D contour digital reconstruction model have good correlation with the changes of the blasting action.The undulation rate of the three-dimensional surface profile of the rock is more prone to dramatic rise and dramatic fall morphology.In terms of tilting trend,the tilting direction also shows gradual disorder,with the tilting angle increasing correspondingly.All the roughness evaluation indexes of the rock fissure surface after blasting show a linear and gradually increasing trend as the distance to the bursting center increases;the difference between the two-dimensional roughness evaluation indexes and the three-dimensional ones of the same micro-area rock samples also becomes increasingly larger,among which the three-dimensional fissure roughness coefficient JRC and the surface roughness ratio Rs display better correlation.Compared with the linear fitting formula of the power function relationship,the three-dimensional fractal dimension of the postblast fissure surface is fitted with the values of JRC and Rs,which renders higher correlation coefficients,and the degree of linear fitting of JRC to the three-dimensional fractal dimension is higher.The fractal characteristics of the blast-affected region form a unity with the three-dimensional roughness evaluation of the fissure surface.
文摘BACKGROUND:Three-dimensional diffusion tensor tract(DTT)is the newest imaging to describe the structure of white matter fiber in three-dimensions,it has great significance in dividing the concrete anatomic site of gray and white matter lesions,displaying the correlation with fibrous band and judging clinical prognosis,which is incomparable by other imagings.OBJECTIVE:To observe the conditions of corticospinal tract(CST)in acute cerebral ischemic stroke patients,and analyze the relationship between motor function and the severity of CST injury.DESIGN:A case-control observation.SETTING:Department of Medical Imaging,Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA.PARTICIPANTS:Fifteen patients with acute cerebral infarction were selected from Fuzhou General Hospital of Nanjing Military Area Command of Chinese PLA from February to December in 2005.They all suffered from acute attack and motor disorder of hemiplegic limbs to different extent,and were conformed by CT or MRI.There were 9 males and 6 females,aging 16-87 years old,the median age was 51.7 years,and all were right handed.Fifteen right-handed normal subjects,who were matched by age and sex with the patients in the cerebral infarction group,were selected from the relatives of patients and physicians of the Imaging Department as the control group.All the subjects were informed and agreed with the study.METHODS:The patients with acute cerebral infarction and subjects in the control group received MR diffusion tensor imaging(DTI)with GE 1.5 T nuclear magnetic resonance system,fiber tracking with the software of dTV-Ⅱ.Fractional anisotropy(FA)maps and three-dimensional tractography of bilateral CST of all patients were created.Displacement,continuity and destroy of fibrous bands were observed.At the same time,muscle strength of ipsilateral hand of patients with cerebral infarction was measured with Brunnstrom standard.The correlation between the severity of CST injury and the muscle strength of ipsilateral hand was analyzed with spearman correlation analysis.MAIN OUTCOME MEASURES:①FA values in the infarcted sites and those in the contralateral corresponding sites of patients with cerebral infarction;②CST manifestations in the patients with cerebral infarction and the control group.RESULTS:All the 30 testees were involved in the analysis of results.①The FA values in infarcted sites of white matter were significantly lower than those in the contralateral ones(t=4.570,P<0.001).②In the control group,bilateral CST were reconstructed,they originated from precentral gyrus,went downwards to internal capsule,and extended to pontine and medulla oblongata,each fiber had good uniformity in continuous form.In the patients with cerebral infarction,the forms of contralateral CST were consistent with those in the control group with good continuity.Due to the involvement by the infarcted site to different extents,the ipsilateral CST manifested as continuous interruption and loss of uniformity in anatomic structure and form.The CST involvements were divided into three grades:integrated CST for grade 1(n=2);integrated CST but compressed or displaced for grade 2(n=5);interrupted CST for grade 3(n=8).③The severity of CST injury was obviously correlated with the muscle strength of the ipsilateral hand(r=0.888,P<0.05).CONCLUSION:①CST is injured to different extents in patients with acute cerebral infarction,and the severity of injury is associated with muscle strength.It is indicated that it can be used to judge the prognosis of rehabilitative treatment.②DTT can directly display the status of pyramidal tract more three-dimensionally.
基金Under the auspices of National Natural Science Foundation of China (No.40635028,40801066)State Key Laboratory of Earth Surface Processes and Resource Ecology of China (No.2008-KF-04)
文摘As natural ecosystems provide the material basis and fundamental support for regional sustainable devel-opment,the sustainability of natural ecosystems is an important prerequisite and a viable approach for the achievement of regional sustainable development.It is also the final criteria to assess whether sustainable development paradigm is successful.Along with the increasing impacts of human activities on natural ecosystems,the evaluation of regional ecological sustainability has become one of the key issues for research on macro ecology and sustainable development.Based on different unit of indicators,this study firstly groups the evaluation frameworks of regional ecological sus-tainability into three major types:comprehensive index evaluation with dimensionless unit,monetary valuation,and biophysical quantity measurement.We then discuss and compare these types in terms of basic principles,scope of ap-plications,advantages and shortcomings.Finally,drawn on the discussion about characteristics of ecological sustain-ability,we outline the current trend and future directions of regional ecological sustainability evaluation,for instance,transition from sustainable development evaluation to sustainability science,integration of goal-oriented and problem-solving approaches,combination of spatial pattern analysis and ecological sustainability evaluation,and en-hancement of ecological sustainability evaluation at landscape scale.
基金supported by the National Natural Science Foundation of China(Nos.21674026,21574032,51573125,51573147,51803149,51973155,and 51633007(the State Key Program))the Sino-German Center for Research Promotion(No.GZ1286)the Chinese Academy of Sciences(No.121D11KYSB20170031).
文摘Two reported three-dimensional covalent organic frameworks(3D-COFs),COF-300 and COF-301,which have hierarchical porous structures and large pore volumes,were synthesized and employed as host materials for lithium-sulfur batteries.Owing to possessing excellent porosities as well as abundant hydroxyl groups in the pore walls,COF-301 can not only trap lithium polysulfides(PSs)via physical adsorption inside the pores,but also capture PSs by chemical interactions to relieve the shuttle effect.Interestingly,it is the first time that 3D-COFs were utilized as host materials for lithium-sulfur batteries as well as hydroxyl groups were introduced into COFs for improving the battery performance.As a result,COF-301@S as cathode material could reserve the capacity of 411.6 mA·h·g^-1 after 500 cycles with only 0.081%fading per cycle at 0.5 C,exhibiting better battery performance compared with COF-300@S.This study not only expands the applications of 3D-COFs but also provides a new route for designing lithium-sulfur batteries.
基金the China National Key R&D Program(Grant No.2019YFA0606900)the National Science Founda-tion of China(Grant No.41771536)the National Science Founda-tion for Distinguished Young Scholars of China(Grant No.51425903)。
文摘Global warming and rapid economic development have led to increased levels of disaster risk in China.Previous attempts at assessing drought risk were highly subjective in terms of assessment methods and selection of the assessment indicators and which resulted in appreciable uncertainty in the results of these risk assessments.Based on the assumption that areas with historically high drought losses are more likely to suffer future high drought losses,we develop a new drought risk assessment model that includes historical drought loss data.With this model,we map the regional differentiation of Chinese drought risk.Regions with high(extreme high)drought risk account for 4.3%of China’s area.Five significant high-risk areas have been identified:Northeast China,North China,the east part of Northwest China,the east part of Southwest China and a small part in the west of Northwest China.Areas with high and extreme high drought risk are dominant in the Heilongjiang Province,accounting for 32%of the total area,followed by the Ningxia Hui Autonomous Region,with 26%of total area.The contribution of each influencing factor has been quantified,which indicates that high-exposure and high-vulnerability account for the high-risk of drought.We recommend that measures like strengthening the protection of cultivated land and reducing dependence on the primary industry should be taken to mitigate to drought-induced losses.
基金the National Natural Science Foundation of China (No. 20271025)the Natural Science Foundation of Shandong province (No. Z2001B02)the State Key Laboratory of Crystal Materials,Shandong University
文摘The bis(tributyltin) ester of succinic acid was synthesized by the reaction of disodium salt of succinic acid with tributyltin chloride in a molar ratio of 1:2. The crystal structure was determined by X-ray single-crystal diffraction. It belongs to orthorhombic with space group Pccn, a = 20.949(3), b = 17.470(3), c = 20.345(3) Angstrom, V = 7446(2) Angstrom(3), Z = 8, D-c = 1.242 g/cm(3), mu = 1.365 mm(-1), F(000) = 2864, R = 0.0544 and wR = 0.1417. The tin atom is of five-coordination in a trigonal bipyramidal structure by bridging two carboxylate groups in different directions and the resulting structure which contains straight twist large ring channels along the axes of a, b and c is a three-dimensional framework polymer containing two different tin atoms.
基金supported by National Natural Science Foundation of China(Nos.22176012,52370025)the Pyramid Talent Training Project of Beijing University of Civil Engineering and Architecture(No.JDLJ20220802)+1 种基金the Doctor Graduate Scientific Research Ability Improvement Project of Beijing University of Civil Engineering and Architecture(No.DG2023014)Guangxi Key Laboratory of Urban Water Environment。
文摘The harmful algal bloom primarily caused by Microcystis aeruginosa(M.aeruginosa)has become one of the serious biological pollution issues in actual water,which has received intense attention worldwide.Over the past years,increasing number of publications have reported that metal-organic frameworks(MOFs)based functional materials exhibited significant inhibition against M.aeruginosa via multiple mechanisms,but no review papers systematically presented progresses regarding MOFs-based materials for M.aeruginosa control up to now.With this review paper,we summarized the state-of-the-art studies of MOFsbased materials for M.aeruginosa removal,comparing and discussing the design strategies of MOFs-based materials and their antimicrobial mechanisms.Meanwhile,we discussed methods for evaluating the water purification performances of MOFs-based materials against M.aeruginosa.Finally,the perspectives for design of novel MOFs-based functional materials and application scenarios were proposed to provide an outlook on areas where greater efforts should be made in the future.
基金This research was supported by the National Social Sciance Foundation of China(20&ZD091)the Sciance and Technology Department Project of Sichuan Province,China(21 RICX0358,2019JDJQ0006)the Social Science Planning Project of Sichuan Province,China(SC18B027).
文摘With the intensi fed impact of human activities,most lakes have been severely disturbed and the lake ecosystem has been seriously damaged,which exerted a great impact on the living envi-ronment of human beings in the lake basins.The health of the lake ecosystem has gradually become one of the hot issues in recent years.In this study,the water resources carrying capacity(WRCC)was used to reveal the chain rel ationship between human activities and water environ-ment in the economic dewelopment of the Dianchi Lake Basin in Kunming City of China during 2005-2015.Specifically,we chose 25 ewaluation indicators related to the water environment and socialeconomic activities,classified them into six subsystems,Le,the driwing force subsystem(D),the water resources si tuation and consumption subsystem(S),the water resources pressure subsystem(P),the water environmental situation subsystem(E),the response subsystem(R),and the management subsystem(M),and built a comprehensive assessment system-DSPERM frame-work model.Si mulated annealing-projection pursuit model which reflects the structure or feature of high-dimensional data was adopted to calculate the WRCC of the Dianchi Lake Basin during 2005-2015 by weighting each evaluation indicator and each subsystem of the DSPERM frame work model.The resuls show that the WRCC of the Dlanchi Lake Basin was in level II(medium carying capacity)from 2005 to 2012.Since 2013,the WRCC has been at level II(strong carying capacity),and from 2005 to 2015,it showed a gradual upward trend.The evaluation indicators of each subsystem varied greatly and exhibited different development trends.The indicators of the water resources pressure subsystem had the greatest impact on the WRCC,followed by the in-dicators of the water environmental si tuation subsystem and the water resources situation and consumption subsystem.We recommend that the DSPERM framework model and the simulated anneal ing-projection pursuit model constructed in this work can be used to analyze the dynamic changes of the WRCC over the years.They have the advantages of practicability and feasibilty,and can provide the basis for the scienti fic decision-making and comprehensive management of regional water environment planning.
文摘Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully constructed by coordinatively assembling the semi-rigid multidentate ligand 5-(1-carboxyethoxy)isophthalic acid(H₃CIA)with the Nheterocyclic ligands 1,4-di(4H-1,2,4-triazol-4-yl)benzene(1,4-dtb)and 1,4-di(1H-imidazol-1-yl)benzene(1,4-dib),respectively,around Co^(2+)ions.Single-crystal X-ray diffraction analysis revealed that in both complexes HU23 and HU24,the CIA^(3-)anions adopt aκ^(7)-coordination mode,bridging six Co^(2+)ions via their five carboxylate oxygen atoms and one ether oxygen atom.This linkage forms tetranuclear[Co4(μ3-OH)2]^(6+)units.These Co-oxo cluster units were interconnected by CIA^(3-)anions to assemble into 2D kgd-type structures featuring a 3,6-connected topology.The 2D layers were further connected by 1,4-dtb and 1,4-dib,resulting in 3D pillar-layered frameworks for HU23 and HU24.Notably,despite the similar configurations of 1,4-dtb and 1,4-dib,differences in their coordination spatial orientations lead to topological divergence in the 3D frameworks of HU23 and HU24.Topological analysis indicates that the frameworks of HU23 and HU24 can be simplified into a 3,10-connected net(point symbol:(4^(10).6^(3).8^(2))(4^(3))_(2))and a 3,8-connected tfz-d net(point symbol:(4^(3))_(2)((4^(6).6^(18).8^(4)))),respectively.This structural differentiation confirms the precise regulatory role of ligands on the topology of metal-organic frameworks.Moreover,the ultraviolet-visible absorption spectra confirmed that HU23 and HU24 have strong absorption capabilities for ultraviolet and visible light.According to the Kubelka-Munk method,their bandwidths were 2.15 and 2.08 eV,respectively,which are consistent with those of typical semiconductor materials.Variable-temperature magnetic susceptibility measurements(2-300 K)revealed significant antiferromagnetic coupling in both complexes,with their effective magnetic moments decreasing markedly as the temperature lowered.CCDC:2457554,HU23;2457553,HU24.
文摘Researchers' understandings of economic, ecological and social benefits of urban green spaces were discussed from many perspectives, connotations of such three major benefits were redefined, existing problems in the present evaluation were analyzed. According to service objects of urban green spaces, 6 relationship fields were classified, specifically, global ecology, regional environment, regional health, basic life, spiritual life and material life, a basic framework for evaluating economic, ecological and social benefits of urban green spaces was proposed.
基金financially supported by the National Natural Science Foundation of China (Nos. 51973153, 22001191)。
文摘Covalent organic frameworks(COFs) are a class of crystalline porous organic materials with variable structures and fascinating properties. The intrinsic low conductivity impedes their widely application in optoelectronic. Iodine doping is an effective way to enhance the electrical conductivity of COFs. Here, a novel 3D imine COF with lvt topology is synthesized from two different pentacene derivatives with the same core in the form of structural complementarity. DDHP-COF is a highly crystalline material featuring high surface area of 1679 m^(2)/g and excellent thermal stability up to 490 ℃. Upon doping with iodine, the electrical conductivity can reach as high as 1.5×10^(-2)S/m which is significantly enhanced over 6 orders of magnitude compared with the pristine COF.
基金supported by the Analysis and Testing Foundation of Northeast Normal University
文摘A new heteropolyoxotungstate [（C2H4N2）4（P4Co3W4O28H6）（H2C2O4）]n with a three-dimensional framework was hydrothermally synthesized.The compound crystallizes in a tetragonal system,space group I41/a with a = 17.1006（17）,b = 17.1006（7）,c = 10.7525（5）,V = 3144.2（2）3,Z = 4,Dc = 3.795 g·cm-3,F（000） = 3300,MoKα（λ = 0.71073 ）,μ = 16.460 mm-1,the final R = 0.0335 and wR = 0.0776.In the heteropolyoxotungstate,tungsten-oxygen octahedra are linked by sharing two cis-vertexes into an infinite helical chain extending along the c axis.Cobalt atoms in the octahedral geometry act as the linkers of these chains,forming a three-dimensional framework.The cobalt and phosphorus atoms in the tetrahedral geometry play a role in stabilizing the three-dimensional framework.Ethylenediamine molecules are polymerized into organic chains which locate in the interspaces of the framework in the way of interwinding with the W-O chains.
文摘[Objective] The aim was to conduct post-evaluation on environmental planning by means of logical framework approach. [Method] Taking environmental planning during '11th Five-year Plan' in a certain province for example, by means of logical framework approach (LFA), the post-evaluation on environmental planning was carried out from the aspects of evaluation content, index system, implementation steps, evaluation feedback and input-output analysis of environmental planning. [Result] The post-evaluation on environmental planning by means of LFA achieved expected purpose and various indexes at different stages of environmental planning was assessed, and then corresponding countermeasures were put forward according to the problems which were found by problem tree of environmental planning project. [Conclusion] The study could provide theoretical references for the post-evaluation on environmental planning in future.
文摘This paper aims to devising an evaluation plan for an Integrated English Course within the RUFDATA framework in an attempt to illuminate the working mechanism of the Framework.
基金partially funded by the Research University Grant Scheme(RUGS),Universiti Putra Malaysia(UPM).
文摘Previous mobile usability studies are only pertinent in the context of ergonomics,physical user interface,and mobility aspects.In addition,much of the previous mobile usability conception was built on desktop computing measurements,such as desktop and web application checklists,or scarcely addressed the mobile user interface.Moreover,the studies focus mainly on interface features for desktop applications and do not reflect comprehensive mobile interface features such as navigation drawers and spinners.Therefore,conducting usability evaluation using conventional usability measurement would result in irrelevant results.In addition,the resulting works are tailored for usability testing,which requires highly skilled evaluators and usability specialists(e.g.,usability testers and user experience designers),who are rarely integrated into a development team.The lack of expertise could lead to unreliable usability evaluations.This paper presents a review from industrial experts on a comprehensive and feasible usability evaluation framework developed in our previous work.The framework is dedicated to smartphone apps,which integrate evaluator skills and design concerns.However,there is no evidence of its usefulness in practice.Therefore,the usefulness of the framework measurement for evaluating apps’usability in the eyes of non-usability specialists is empirically assessed in this paper through an expert review.The expert review involved eleven industrial developers and was complemented by a semi-structured interview.The method is replicated in comparison with a framework from another study.The findings show that the formulated framework significantly outperformed the framework(p=0.0286)from other studies with large effect sizes(r=1.81)in terms of usefulness.
基金supported by the National Planning Office of Philosophy and Social Science(Grant No.06BTQ027)
文摘The evolution of the society and economy has stimulated the development of Knowledge Service(KS), making it an indispensable solution to address future challenges facing libraries and information institutions. However at present, academic research on knowledge service is falling short and its definition is far from clear and complete. As such,this article proposes the Three-dimensional Framework Knowledge Service(TdFKS) for libraries and information institutions based on the knowledge value chain model. By making reliability analysis and mean value analysis of a questionnaire survey result, the article clarifies the structure of the three-dimensional framework and verifies the rationality of the TdFKS.
文摘The Critical Discourse Analysis(CDA)is an interdisciplinary tool in various conditions,which aims to provide a better understanding of sociocultural aspects of texts and accounts of the production of internal structure,and overall organization of texts as well as to provide a critical dimension in its theoretical and descriptive accounts of texts.Since June last year,HK protests or HK violence have been frequently reported by worldwide media.In this paper,the author aims to find out how the HK protesters and the Mainland media describe the same event based on the three-dimensional framework of CDA.At last,the author concludes that the mainland media generally describe the event as violence and riot while the HK protesters define themselves as warriors striving for more freedom,justice and democracy.Besides,on this event,the Mainland media mainly accuses some western countries of interference into HK affairs,which is undoubtedly of China’s internal affairs,and the media give full support to the HK police in safeguarding the peace and stability of Hong Kong.But from the perspective of HK protesters,they firmly believe that they are using their actions to protect all the people of HK,and they are defending their values such as freedom,democracy and justice.These are two totally different systems of language,and the author also gives its potential reasons in the paper so as to offer some viewpoints in this aspect in combination with the CDA theory.
基金funded by National Basic Research Program of China (2013CBA01804, 2013CBA01808)Technology Services Network Program (STS-HHS Program) of Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciencesthe independent subject from Stake Key Laboratory of Cryospheric Sciences, Chinese Academy of Sciences
文摘Cryosphere science research and development(R&D) has been strongly committed to public service, integrating natural sciences with socioeconomic impacts. Owing to the current shift from purely natural cryosphere scientific research to linking cryosphere science with socioeconomic and cultural science, cross-disciplinary research in this field is emerging, which advocates future cryosphere science research in this field. Utilizing the cryosphere service function(CSF), this study establishes CSF and its value evaluation system. Cryosphere service valuation can benefit the decisionmakers' and public's awareness of environmental protection. Implementing sustainable CSF utilization strategies and macroeconomic policymaking for global environmental protection will have profound and practical significance as well as avoid environmental degradation while pursuing short-term economic profits and achieving rapid economic development.
