The assessment of in situ permeability of rock mass is challenging for large-scale projects such as reservoirs created by dams,where water tightness issues are of prime importance.The in situ permeability is strongly ...The assessment of in situ permeability of rock mass is challenging for large-scale projects such as reservoirs created by dams,where water tightness issues are of prime importance.The in situ permeability is strongly related to the frequency and distribution of discontinuities in the rock mass and quantified by rock quality designation(RQD).This paper analyzes the data of hydraulic conductivity and discontinuities sampled at different depths during the borehole investigations in the limestone and sandstone formations for the construction of hydraulic structures in Oman.Cores recovered from boreholes provide RQD data,and in situ Lugeon tests elucidate the permeability.A modern technique of multivariate adaptive regression splines(MARS)assisted in correlating permeability and RQD along with the depth.In situ permeability shows a declining trend with increasing RQD,and the depth of investigation is within 50 m.This type of relationship can be developed based on detailed initial investigations at the site where the hydraulic conductivity of discontinuous rocks is required to be delineated.The relationship can approximate the permeability by only measuring the RQD in later investigations on the same site,thus saving the time and cost of the site investigations.The applicability of the relationship developed in this study to another location requires a lithological similarity of the rock mass that can be verified through preliminary investigation at the site.展开更多
Rock quality designation(RQD)has been considered as a one-dimensional jointing degree property since it should be determined by measuring the core lengths obtained from drilling.Anisotropy index of jointing degree(AI_...Rock quality designation(RQD)has been considered as a one-dimensional jointing degree property since it should be determined by measuring the core lengths obtained from drilling.Anisotropy index of jointing degree(AI_(jd))was formulated by Zheng et al.(2018)by considering maximum and minimum values of RQD for a jointed rock medium in three-dimensional space.In accordance with spacing terminology by ISRM(1981),defining the jointing degree for the rock masses composed of extremely closely spaced joints as well as for the rock masses including widely to extremely widely spaced joints is practically impossible because of the use of 10 cm as a threshold value in the conventional form of RQD.To overcome this limitation,theoretical RQD(TRQD_(t))introduced by Priest and Hudson(1976)can be taken into consideration only when the statistical distribution of discontinuity spacing has a negative exponential distribution.Anisotropy index of the jointing degree was improved using TRQD_(t) which was adjusted to wider joint spacing by considering Priest(1993)’s recommendation on the use of variable threshold value(t)in TRQD_(t) formulation.After applications of the improved anisotropy index of a jointing degree(AI'_(jd))to hypothetical jointed rock mass cases,the effect of persistency of joints on structural anisotropy of rock mass was introduced to the improved AI'_(jd) formulation by considering the ratings of persistency of joints as proposed by Bieniawski(1989)’s rock mass rating(RMR)classification.Two real cases were assessed in the stratified marl and the columnar basalt using the weighted anisotropy index of jointing degree(W_AI'_(jd)).A structural anisotropy classification was developed using the RQD classification proposed by Deere(1963).The proposed methodology is capable of defining the structural anisotropy of a rock mass including joint pattern from extremely closely to extremely widely spaced joints.展开更多
The study aimed at assessment of level of task performance of Primary Health Care Worker （PHCWs） according to their professional designations in selected Local Government Areas （LGA） in Enugu State. Descriptive su...The study aimed at assessment of level of task performance of Primary Health Care Worker （PHCWs） according to their professional designations in selected Local Government Areas （LGA） in Enugu State. Descriptive survey research was used. 291 PHCWs were randomly selected from 9 LGA using a multistage method. Questionnaire was used to collect data and the instrument was validated using test-retest method with correlation coefficient of 0.79. The findings show that Community Health Extension Workers （CHEWs） performed higher than Environmental Health Officer （EVO） and Community Health Officers （CHOs） in the area of health education concerning prevailing health problems and method of control. They scored 66.09% as against 52.8% and 60.61% for EVO and CHEW respectively. The result showed that the professional designation has no significant effect （P 〈 0.05） on the level of task performed by PHCW and their levels of task performance were low. It was recommended that public Health physicians and Nurses should be involved in the PHC in Enugu State to provide the fight supervision to the PHCW.展开更多
Objective To analyze the characteristics of breakthrough therapy designation(BTD)and its implementation in China,and to provide reference for the optimization of BTD system.Methods A comparative research method was us...Objective To analyze the characteristics of breakthrough therapy designation(BTD)and its implementation in China,and to provide reference for the optimization of BTD system.Methods A comparative research method was used to study the content and implementation effect of BTD system in China and the relevant policies and implementation of the same procedures of drug regulatory authorities in the United States,Japan and the European Union.Then,the differences in policies and implementation results among these countries were analyzed to provide suggestions for the implementation and optimization of this system in China.Results and Conclusion China’s BTD system is implemented late and a small number of drugs has been approved.At the same time,there are problems such as insufficient guidance and communication from the agency to applicants,a broad application condition,single review mode,and lack of full-time personnel.Both the agencies and the applicants have limited experience due to the short implementation time of BTD system in China.There are still some problems despite we have learned a lot from the experience of other drug regulatory agencies.Therefore,based on our national conditions,we should strengthen the guidance of evaluation agency to applicants,optimize the eligibility criteria of BTD system,introduce the rolling review,and increase the number of professional liaisons,which can accelerate the development and marketing process of drugs with obvious clinical value,and finally to address unmet medical need.展开更多
With the development of camera technology,high-speed cameras have greatly contributed to capturing the movement and posture of animals,which has dramatically promoted experimental biology research.At the same time,wit...With the development of camera technology,high-speed cameras have greatly contributed to capturing the movement and posture of animals,which has dramatically promoted experimental biology research.At the same time,with the concept of bionics gradually gaining popularity among researchers,the design of robots is absorbing more and more biological features,where the interest in the bio-inspired robot is hewed out.Compared with the traditional robot,the bio-inspired robot imitates the motion pattern to achieve similar propulsion features,which may be more effective and reasonable.In this paper,the motion patterns of aquatic animals are divided into four categories according to their propulsion mechanisms:drag-based,lift-based,jet-based,and interface-based.And bio-inspired robots imitating aquatic prototypes are introduced and reviewed.Finally,the prospect of aquatic bio-inspired robots is discussed.展开更多
A chemometric and sensory study was conducted of ten Spanish red wines,all described as“Tempranillo Crianza 2010”,with Protected Designation of Origin(PDO).The analysis considered the following physicochemical param...A chemometric and sensory study was conducted of ten Spanish red wines,all described as“Tempranillo Crianza 2010”,with Protected Designation of Origin(PDO).The analysis considered the following physicochemical parameters:alcohol content,SO_(2) level,acidity,tannin,antioxidant capacity and colour.In the chemometric study,Principal Component Analysis of the colour,Cluster Analysis,Analysis Of Variance(ANOVA)and the Kruskal-Wallis test showed that the samples corresponding to PDOs#8,#9 and#10 presented the highest number of differences from the rest.In the sensory analysis,Samples#9 and#10 were identified as the most different.From both types of study,we conclude that Samples#8,#9 and#10 present the greatest differences,while the remaining samples were very similar in their chemometric and sensory characteristics.展开更多
The pandemic due to the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the etiological agent of coronavirus disease 2019(COVID-19),has caused immense global disruption.With the rapid accumulation of SARS-...The pandemic due to the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the etiological agent of coronavirus disease 2019(COVID-19),has caused immense global disruption.With the rapid accumulation of SARS-CoV-2 genome sequences,however,thousands of genomic variants of SARSCoV-2 are now publicly available.To improve the tracing of the viral genomes’evolution during the development of the pandemic,we analyzed single nucleotide variants(SNVs)in 121,618 high-quality SARS-CoV-2 genomes.We divided these viral genomes into two major lineages(L and S)based on variants at sites 8782 and 28144,and further divided the L lineage into two major sublineages(L1 and L2)using SNVs at sites 3037,14408,and 23403.Subsequently,we categorized them into 130 sublineages(37 in S,35 in L1,and 58 in L2)based on marker SNVs at 201 additional genomic sites.This lineage/sublineage designation system has a hierarchical structure and reflects the relatedness among the subclades of the major lineages.We also provide a companion website(www.covid19evolution.net)that allows users to visualize sublineage information and upload their own SARS-CoV-2 genomes for sublineage classification.Finally,we discussed the possible roles of compensatory mutations and natural selection during SARS-CoV-2’s evolution.These efforts will improve our understanding of the temporal and spatial dynamics of SARS-CoV-2’s genome evolution.展开更多
In China, central towns are an important pitch point in the urban system of a city or county. The cultivation and development of central towns is significant in completing the urban system structure and improving the ...In China, central towns are an important pitch point in the urban system of a city or county. The cultivation and development of central towns is significant in completing the urban system structure and improving the overall quality of urban-rural development of a city or county. In the Municipality of Shiyan, a mountainous region in Hubei Province, the designation of central towns should not be mechanically accomplished through applying the methodology used in plain areas, but with particular focus on the location and transportation of the towns. Based on the analysis of comprehensive development potential, 14 central towns are finally designated in Shiyan in view of their favorable location and the requirement of coordinated regional development. Development strategies are also proposed for them which include the improvement of urban functions, the differentiation of development modes, the growth of industrial clusters, the development of environmental-friendly industries, the standard configuration of public service facilities, and the institutional reform and innovation which would ensure the realization of the central towns' function of agglomeration and radiation.展开更多
In this study,an inverse design framework was established to find lightweight honeycomb structures(HCSs)with high impact resistance.The hybrid HCS,composed of re-entrant(RE)and elliptical annular re-entrant(EARE)honey...In this study,an inverse design framework was established to find lightweight honeycomb structures(HCSs)with high impact resistance.The hybrid HCS,composed of re-entrant(RE)and elliptical annular re-entrant(EARE)honeycomb cells,was created by constructing arrangement matrices to achieve structural lightweight.The machine learning(ML)framework consisted of a neural network(NN)forward regression model for predicting impact resistance and a multi-objective optimization algorithm for generating high-performance designs.The surrogate of the local design space was initially realized by establishing the NN in the small sample dataset,and the active learning strategy was used to continuously extended the local optimal design until the model converged in the global space.The results indicated that the active learning strategy significantly improved the inference capability of the NN model in unknown design domains.By guiding the iteration direction of the optimization algorithm,lightweight designs with high impact resistance were identified.The energy absorption capacity of the optimal design reached 94.98%of the EARE honeycomb,while the initial peak stress and mass decreased by 28.85%and 19.91%,respectively.Furthermore,Shapley Additive Explanations(SHAP)for global explanation of the NN indicated a strong correlation between the arrangement mode of HCS and its impact resistance.By reducing the stiffness of the cells at the top boundary of the structure,the initial impact damage sustained by the structure can be significantly improved.Overall,this study proposed a general lightweight design method for array structures under impact loads,which is beneficial for the widespread application of honeycomb-based protective structures.展开更多
Carotenoid cleavage dioxygenase 4(CCD4)controls the rate-limiting step ofβ-ionone biosynthesis,making it a valuable target for healthcare and pharmaceutical applications.Nicotiana tabacum,a carotenoid-richd crop spec...Carotenoid cleavage dioxygenase 4(CCD4)controls the rate-limiting step ofβ-ionone biosynthesis,making it a valuable target for healthcare and pharmaceutical applications.Nicotiana tabacum,a carotenoid-richd crop species,is a promising source forβ-ionone production.This study aimed to modify CCD4 activity to increaseβ-ionone yield in tobacco.We identified two isoforms of CCD4 in N.tabacum,NtCCD4a and NtCCD4b,with NtCCD4a exhibiting significantly higher expression levels than NtCCD4b.Using solid-phase microextraction gas chromatography-mass spectrometry(SPME-GC–MS),we demonstrated that NtCCD4a effectively catalyzes the cleavage ofβ-carotene to produceβ-ionone.To improve its enzymatic activity,we applied structure-based rational design to reconstruct the active pocket of NtCCD4a,followed by high-throughput screening of mutant variants.Three single base mutants,F181G,F184L,and F337M,in NtCCD4a showed enhancedβ-ionone production compared to the wild-type,with F337M yielding the highest amount.No synergistic effects were observed among the three mutants.Transgenic tobacco plants expressing the F181G,F184L,and F337M mutations had acceleratedβ-carotene cleavage and increasedβ-ionone production relative to the wild-type NtCCD4a.Our results establish a framework for the design of CCD4 in major crop species through genome editing technology.展开更多
Biological nitrogen fixation(BNF)and photosynthetic carbon fixation underpin food production and climate mitigation,yet natural systems are constrained by oxygen sensitivity,high energy demand,and inefficient catalyst...Biological nitrogen fixation(BNF)and photosynthetic carbon fixation underpin food production and climate mitigation,yet natural systems are constrained by oxygen sensitivity,high energy demand,and inefficient catalysts.This review synthesizes advances that recast these processes as engineering targets and proposes a conceptual roadmap that bridges synthetic symbioses with the synthetic biology of enzymes and pathways.For BNF,progress spans cross-kingdom strategies—from refactoring nif gene sets and targeting nitrogenase assembly to eukaryotic organelles,to engineering plant-associated diazotrophs,rhizosphere control circuits,and emerging nodule-like microenvironments.For carbon assimilation,new-to-nature CO_(2)-fixation modules and photorespiratory bypasses illustrate how pathway redesign and alternative carboxylases can circumvent key Calvin–Benson–Bassham limitations,and expanding photosynthetic light capture offers additional leverage.Across these domains,we extract common design principles:(i)nitrogenase output is increasingly governed by carbon/energy supply and electron delivery as much as by oxygen protection;(ii)robust function requires compartment-aware enzyme–chassis coordination,substrate channeling,and dynamic regulation using sensors and control circuits;and(iii)scalable implementation may benefit from distributing metabolic labor across engineered consortia rather than forcing all functions into a single host.We discuss enabling technologies—including AI-guided protein design and directed evolution,cell-free prototyping,chassis toolkits,and materials/bioelectrochemical interfaces—that can accelerate design–build–test–learn cycles and reduce barriers to deployment.Together,these insights define a path toward integrated nitrogen and carbon fixation systems for low-emission agriculture and biomanufacturing.展开更多
Biomass-based hydrocarbon fuels,as one of the alternatives to traditional fossil fuels,have attracted considerable attention in the energy field due to their renewability and environmental benefits.This article provid...Biomass-based hydrocarbon fuels,as one of the alternatives to traditional fossil fuels,have attracted considerable attention in the energy field due to their renewability and environmental benefits.This article provides a systematic review of recent research progress in the chemical synthesis of biomass-based hydrocarbon fuels.It outlines the conversion pathways using feedstocks such as lipids,terpenoids,cellulose/hemicellulose,and lignin.Depending on the feedstock,various products with distinct structural characteristics can be prepared through reactions such as cyclization,condensation,and catalytic hydrogenation.Throughout the synthesis process,three key factors play a critical role:efficient catalyst development,production process optimization,and computational-chemistry-based molecular design.Finally,the article discusses future perspectives for biomass-based hydrocarbon fuel synthesis research.展开更多
Filters,as a key component in the photoelectric detection system,can simplify the optical system and improve detection efficiency.Based on the usage requirements,a visible/near-infrared filter film with up to 5 waveba...Filters,as a key component in the photoelectric detection system,can simplify the optical system and improve detection efficiency.Based on the usage requirements,a visible/near-infrared filter film with up to 5 wavebands needs to be designed and prepared,while simultaneously satisfying high reflection in 2 wave-bands and high transmittance in 3 wavebands.Therefore,we have conducted a systematic study on the film design,thin film preparation process,and control accuracy of film layer thickness.In this work,the short-wave pass film system is superimposed with the long-wave pass film system,and the number of cycles and matching coefficient of the film system are tuned to meet the requirements of cut-off band.Additionally,Smith method was used to match bandpass film system to optimize the transmission band and complete the visible/near infrared multiband laser filter film design.In the preparation process,combined with the sensitiv-ity of the film layer,inverse analysis is used to invert the film layer monitored by each optical monitoring chip.The optical control scheme with weak optical signal in the monitoring process is simulated and correc-ted,and the monitoring wavelength with stronger optical signal is matched,resulting in an improvement of the control accuracy for the film thickness and the transmittance in the specified wavelength range.Ulti-mately,the actual physical thickness is 9.66μm,and the error with the theoretical design thickness is less than 0.4%,and the transmittance of the specified 3 wavebands exceeds 99%.The average transmittance of the cut-off bands at the 455−500 nm and 910−1000 nm is 0.45% and 0.16%,respectively.展开更多
Against the backdrop of escalating global climate change and energy crises,the resource utilization of carbon dioxide(CO_(2)),a major greenhouse gas,has become a crucial pathway for achieving carbon peaking and carbon...Against the backdrop of escalating global climate change and energy crises,the resource utilization of carbon dioxide(CO_(2)),a major greenhouse gas,has become a crucial pathway for achieving carbon peaking and carbon neutrality goals.The hydrogenation of CO_(2)to methanol not only enables carbon sequestration and recycling,but also provides a route to produce high value-added fuels and basic chemical feedstocks,holding significant environmental and economic potential.However,this conversion process is thermodynamically and kinetically limited,and traditional catalyst systems(e.g.,Cu/ZnO/Al_(2)O_(3))exhibit inadequate activity,selectivity,and stability under mild conditions.Therefore,the development of novel high-performance catalysts with precisely tunable structures and functionalities is imperative.Metal-organic frameworks(MOFs),as crystalline porous materials with high surface area,tunable pore structures,and diverse metal-ligand compositions,have the great potential in CO_(2)hydrogenation catalysis.Their structural design flexibility allows for the construction of well-dispersed active sites,tailored electronic environments,and enhanced metal-support interactions.This review systematically summarizes the recent advances in MOF-based and MOF-derived catalysts for CO_(2)hydrogenation to methanol,focusing on four design strategies:(1)spatial confinement and in situ construction,(2)defect engineering and ion-exchange,(3)bimetallic synergy and hybrid structure design,and(4)MOF-derived nanomaterial synthesis.These approaches significantly improve CO_(2)conversion and methanol selectivity by optimizing metal dispersion,interfacial structures,and reaction pathways.The reaction mechanism is further explored by focusing on the three main reaction pathways:the formate pathway(HCOO*),the RWGS(Reverse Water Gas Shift reaction)+CO*hydrogenation pathway,and the trans-COOH pathway.In situ spectroscopic studies and density functional theory(DFT)calculations elucidate the formation and transformation of key intermediates,as well as the roles of active sites,metal-support interfaces,oxygen vacancies,and promoters.Additionally,representative catalytic performance data for MOFbased systems are compiled and compared,demonstrating their advantages over traditional catalysts in terms of CO_(2)conversion,methanol selectivity,and space-time yield.Future perspectives for MOF-based CO_(2)hydrogenation catalysts will prioritize two main directions:structural design and mechanistic understanding.The precise construction of active sites through multi-metallic synergy,defect engineering,and interfacial electronic modulation should be made to enhance catalyst selectivity and stability.In addition,advanced in situ characterization techniques combined with theoretical modeling are essential to unravel the detailed reaction mechanisms and intermediate behaviors,thereby guiding rational catalyst design.Moreover,to enable industrial application,challenges related to thermal/hydrothermal stability,catalyst recyclability,and cost-effective large-scale synthesis must be addressed.The development of green,scalable preparation methods and the integration of MOF catalysts into practical reaction systems(e.g.,flow reactors)will be crucial for bridging the gap between laboratory research and commercial deployment.Ultimately,multi-scale structure-performance optimization and catalytic system integration will be vital for accelerating the industrialization of MOF-based CO_(2)-to-methanol technologies.展开更多
Evaluating Adherence to Safety Standards for Physical Space Design, Equipment, and Patient and Staff Protection in Magnetic Resonance Imaging Centers:A Descriptive Cross-sectional Study Amirreza Sadeghinasab1, Jafar F...Evaluating Adherence to Safety Standards for Physical Space Design, Equipment, and Patient and Staff Protection in Magnetic Resonance Imaging Centers:A Descriptive Cross-sectional Study Amirreza Sadeghinasab1, Jafar Fatahiasl2, Mahmoud Mohammadi-Sadr1, Masoud Heydari Kahkesh3, and Marziyeh Tahmasbi2(1.Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran;2.Department of Radiologic Technology, School of Allied Medical Sciences, Ahvaz, Jundishapur University of Medical Sciences, Ahvaz, Iran;3.Department of Radiology and Radiotherapy, School of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran)Abstract:Magnetic resonance imaging(MRI) has revolutionized disease diagnosis and treatment.However, the technology poses safety risks, such as exposure to magnetic fields, RF pulses, and cryogens, necessitating strict adherence to safety protocols to protect patients and healthcare workers.展开更多
A two-level,quasi-geostrophic long-wave model based on spherical coordinates was developed with the explicit part belonging to a low-order model.However,it includes not only diabatic heating,Ekman fric- tion and mount...A two-level,quasi-geostrophic long-wave model based on spherical coordinates was developed with the explicit part belonging to a low-order model.However,it includes not only diabatic heating,Ekman fric- tion and mountain distribution,but also parameterized forcing effects of transfer properties of transient eddies. Experiment results showed that,due to the introduction of the parameterization of transfer properties of transient eddies,remarkable improvements on characters of low-order model had been obtained.In addition to its economization in calculation and conciseness in physics as in a low-order model,the long- wave model was shown to describe the energetics and angular momentum balance of the atmosphere much more reasonably,and to present the features of zonal mean westerlies and stationary waves much more correctly than the corresponding low-order model.This kind of long-wave model was therefore regarded as suitable for theoretical research and numerical modelling of some aspects of the general circulation of the atmosphere.展开更多
The electrochemical oxidation of biomass-derived platform molecule 5-hydroxymethylfurfural(HMF)represents a crucial pathway for green transformation into high-value chemicals,yet its reaction pathway selectivity,effic...The electrochemical oxidation of biomass-derived platform molecule 5-hydroxymethylfurfural(HMF)represents a crucial pathway for green transformation into high-value chemicals,yet its reaction pathway selectivity,efficiency,and catalyst stability are strongly dependent on the electrolyte pH environment.Under alkaline conditions,high OH−concentration facilitates preferential aldehyde group oxidation and efficient deprotonation,enabling highly efficient synthesis of 2,5-furandicarboxylic acid,but simultaneously induces HMF self-degradation and complicates product separation.As pH decreases,the reaction mechanism shifts toward enhanced hydroxymethyl oxidation,leading to intermediate accumulation(such as 5-hydroxymethyl-2-furancarboxylic acid,2,5-diformylfuran,and 5-formyl-2-furancarboxylic acid)with challenging selectivity control and significantly slowed reaction kinetics.This review comprehensively examines the systematic differences in HMF oxidation pathways and surface catalytic mechanisms across the full pH range from alkaline to acidic conditions.Addressing the distinct reaction characteristics and core challenges in alkaline,near-neutral,and acidic media,we systematically evaluate design strategies for high-efficiency electrocatalysts and explore reactor design aspects.Future research should focus on process integration(with tailored reactor design)for energy consumption reduction in alkaline systems,targeted synthesis of diverse oxidation products in near-neutral systems,and innovative catalyst development for acidic systems,thereby advancing the efficiency,selectivity,and practical application of HMF electrooxidation technologies across the entire pH spectrum through synergistic optimization of catalyst,reactor,and process.展开更多
With the rapid growth of cloud computing,the number of data centers(DCs)continuously increases,leading to a high-energy consumption dilemma.Cooling,apart from IT equipment,represents the largest energy consumption in ...With the rapid growth of cloud computing,the number of data centers(DCs)continuously increases,leading to a high-energy consumption dilemma.Cooling,apart from IT equipment,represents the largest energy consumption in DCs.Passive design(PD)and active design(AD)are two important approaches in architectural design to reduce energy consumption.However,for DC cooling,few studies have summarized AD,and there are almost no studies on PD.Based on existing international research(2005-2024),this paper summarizes the current state of cooling strategies for DCs.PD encompasses floors,ceilings,and layout and zoning of racks.Additionally,other passive strategies not yet studied in DCs are critically examined.AD includes air,liquid,free,and two-phase cooling.This paper systematically compares the performance of different AD technologies on various KPIs,including energy,economic,and environmental indicators.This paper also explores the application of different cooling design strategies through best-practice examples and presents advanced algorithms for energy management in operational DCs.This study reveals that free cooling is widely employed,with Artificial Neural Networks emerging as the most popular algorithm for managing cooling energy.Finally,this paper suggests four future directions for reducing cooling energy in DCs,with a focus on the development of passive strategies.This paper provides an overview and guide to DC energy-consumption issues,emphasizes the importance of implementing passive and active design strategies to reduce DC cooling energy consumption,and provides directions and references for future energy-efficient DC designs.展开更多
基金indebted to the Sohar University and the University of Buraimi, Oman, to support this study
文摘The assessment of in situ permeability of rock mass is challenging for large-scale projects such as reservoirs created by dams,where water tightness issues are of prime importance.The in situ permeability is strongly related to the frequency and distribution of discontinuities in the rock mass and quantified by rock quality designation(RQD).This paper analyzes the data of hydraulic conductivity and discontinuities sampled at different depths during the borehole investigations in the limestone and sandstone formations for the construction of hydraulic structures in Oman.Cores recovered from boreholes provide RQD data,and in situ Lugeon tests elucidate the permeability.A modern technique of multivariate adaptive regression splines(MARS)assisted in correlating permeability and RQD along with the depth.In situ permeability shows a declining trend with increasing RQD,and the depth of investigation is within 50 m.This type of relationship can be developed based on detailed initial investigations at the site where the hydraulic conductivity of discontinuous rocks is required to be delineated.The relationship can approximate the permeability by only measuring the RQD in later investigations on the same site,thus saving the time and cost of the site investigations.The applicability of the relationship developed in this study to another location requires a lithological similarity of the rock mass that can be verified through preliminary investigation at the site.
基金supports from the General Directorate of ETIMADEN enterprises during the field studies at Simav open pit mine。
文摘Rock quality designation(RQD)has been considered as a one-dimensional jointing degree property since it should be determined by measuring the core lengths obtained from drilling.Anisotropy index of jointing degree(AI_(jd))was formulated by Zheng et al.(2018)by considering maximum and minimum values of RQD for a jointed rock medium in three-dimensional space.In accordance with spacing terminology by ISRM(1981),defining the jointing degree for the rock masses composed of extremely closely spaced joints as well as for the rock masses including widely to extremely widely spaced joints is practically impossible because of the use of 10 cm as a threshold value in the conventional form of RQD.To overcome this limitation,theoretical RQD(TRQD_(t))introduced by Priest and Hudson(1976)can be taken into consideration only when the statistical distribution of discontinuity spacing has a negative exponential distribution.Anisotropy index of the jointing degree was improved using TRQD_(t) which was adjusted to wider joint spacing by considering Priest(1993)’s recommendation on the use of variable threshold value(t)in TRQD_(t) formulation.After applications of the improved anisotropy index of a jointing degree(AI'_(jd))to hypothetical jointed rock mass cases,the effect of persistency of joints on structural anisotropy of rock mass was introduced to the improved AI'_(jd) formulation by considering the ratings of persistency of joints as proposed by Bieniawski(1989)’s rock mass rating(RMR)classification.Two real cases were assessed in the stratified marl and the columnar basalt using the weighted anisotropy index of jointing degree(W_AI'_(jd)).A structural anisotropy classification was developed using the RQD classification proposed by Deere(1963).The proposed methodology is capable of defining the structural anisotropy of a rock mass including joint pattern from extremely closely to extremely widely spaced joints.
文摘The study aimed at assessment of level of task performance of Primary Health Care Worker （PHCWs） according to their professional designations in selected Local Government Areas （LGA） in Enugu State. Descriptive survey research was used. 291 PHCWs were randomly selected from 9 LGA using a multistage method. Questionnaire was used to collect data and the instrument was validated using test-retest method with correlation coefficient of 0.79. The findings show that Community Health Extension Workers （CHEWs） performed higher than Environmental Health Officer （EVO） and Community Health Officers （CHOs） in the area of health education concerning prevailing health problems and method of control. They scored 66.09% as against 52.8% and 60.61% for EVO and CHEW respectively. The result showed that the professional designation has no significant effect （P 〈 0.05） on the level of task performed by PHCW and their levels of task performance were low. It was recommended that public Health physicians and Nurses should be involved in the PHC in Enugu State to provide the fight supervision to the PHCW.
基金Special Fund for Academy of Pharmaceutical Regulatory Sciences of Research Base for Drug Regulatory Science of National Medical Products Administration-Shenyang Pharmaceutical University(2021jgkx004).
文摘Objective To analyze the characteristics of breakthrough therapy designation(BTD)and its implementation in China,and to provide reference for the optimization of BTD system.Methods A comparative research method was used to study the content and implementation effect of BTD system in China and the relevant policies and implementation of the same procedures of drug regulatory authorities in the United States,Japan and the European Union.Then,the differences in policies and implementation results among these countries were analyzed to provide suggestions for the implementation and optimization of this system in China.Results and Conclusion China’s BTD system is implemented late and a small number of drugs has been approved.At the same time,there are problems such as insufficient guidance and communication from the agency to applicants,a broad application condition,single review mode,and lack of full-time personnel.Both the agencies and the applicants have limited experience due to the short implementation time of BTD system in China.There are still some problems despite we have learned a lot from the experience of other drug regulatory agencies.Therefore,based on our national conditions,we should strengthen the guidance of evaluation agency to applicants,optimize the eligibility criteria of BTD system,introduce the rolling review,and increase the number of professional liaisons,which can accelerate the development and marketing process of drugs with obvious clinical value,and finally to address unmet medical need.
基金This work was supported by National Natural Science Foundation of China(62273042,61773064,61503028).
文摘With the development of camera technology,high-speed cameras have greatly contributed to capturing the movement and posture of animals,which has dramatically promoted experimental biology research.At the same time,with the concept of bionics gradually gaining popularity among researchers,the design of robots is absorbing more and more biological features,where the interest in the bio-inspired robot is hewed out.Compared with the traditional robot,the bio-inspired robot imitates the motion pattern to achieve similar propulsion features,which may be more effective and reasonable.In this paper,the motion patterns of aquatic animals are divided into four categories according to their propulsion mechanisms:drag-based,lift-based,jet-based,and interface-based.And bio-inspired robots imitating aquatic prototypes are introduced and reviewed.Finally,the prospect of aquatic bio-inspired robots is discussed.
基金supported by the European Research Commission(Research Executive Agency)under de research project Stance4Health under Grant(Contract N°816303)by the Plan Propio de Investigacion y Transferencia of the University of Granada under the program“Intensificacion de la Investigacion,modalidad B”.
文摘A chemometric and sensory study was conducted of ten Spanish red wines,all described as“Tempranillo Crianza 2010”,with Protected Designation of Origin(PDO).The analysis considered the following physicochemical parameters:alcohol content,SO_(2) level,acidity,tannin,antioxidant capacity and colour.In the chemometric study,Principal Component Analysis of the colour,Cluster Analysis,Analysis Of Variance(ANOVA)and the Kruskal-Wallis test showed that the samples corresponding to PDOs#8,#9 and#10 presented the highest number of differences from the rest.In the sensory analysis,Samples#9 and#10 were identified as the most different.From both types of study,we conclude that Samples#8,#9 and#10 present the greatest differences,while the remaining samples were very similar in their chemometric and sensory characteristics.
基金supported by the National Natural Science Foundation of China(91731301 and U1902201)the Ministry of Science and Technology of the People’s Republic of China(2020YFC0847000)the Light of West China Program of the Chinese Academy of Sciences.
文摘The pandemic due to the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the etiological agent of coronavirus disease 2019(COVID-19),has caused immense global disruption.With the rapid accumulation of SARS-CoV-2 genome sequences,however,thousands of genomic variants of SARSCoV-2 are now publicly available.To improve the tracing of the viral genomes’evolution during the development of the pandemic,we analyzed single nucleotide variants(SNVs)in 121,618 high-quality SARS-CoV-2 genomes.We divided these viral genomes into two major lineages(L and S)based on variants at sites 8782 and 28144,and further divided the L lineage into two major sublineages(L1 and L2)using SNVs at sites 3037,14408,and 23403.Subsequently,we categorized them into 130 sublineages(37 in S,35 in L1,and 58 in L2)based on marker SNVs at 201 additional genomic sites.This lineage/sublineage designation system has a hierarchical structure and reflects the relatedness among the subclades of the major lineages.We also provide a companion website(www.covid19evolution.net)that allows users to visualize sublineage information and upload their own SARS-CoV-2 genomes for sublineage classification.Finally,we discussed the possible roles of compensatory mutations and natural selection during SARS-CoV-2’s evolution.These efforts will improve our understanding of the temporal and spatial dynamics of SARS-CoV-2’s genome evolution.
文摘In China, central towns are an important pitch point in the urban system of a city or county. The cultivation and development of central towns is significant in completing the urban system structure and improving the overall quality of urban-rural development of a city or county. In the Municipality of Shiyan, a mountainous region in Hubei Province, the designation of central towns should not be mechanically accomplished through applying the methodology used in plain areas, but with particular focus on the location and transportation of the towns. Based on the analysis of comprehensive development potential, 14 central towns are finally designated in Shiyan in view of their favorable location and the requirement of coordinated regional development. Development strategies are also proposed for them which include the improvement of urban functions, the differentiation of development modes, the growth of industrial clusters, the development of environmental-friendly industries, the standard configuration of public service facilities, and the institutional reform and innovation which would ensure the realization of the central towns' function of agglomeration and radiation.
基金the financial supports from National Key R&D Program for Young Scientists of China(Grant No.2022YFC3080900)National Natural Science Foundation of China(Grant No.52374181)+1 种基金BIT Research and Innovation Promoting Project(Grant No.2024YCXZ017)supported by Science and Technology Innovation Program of Beijing institute of technology under Grant No.2022CX01025。
文摘In this study,an inverse design framework was established to find lightweight honeycomb structures(HCSs)with high impact resistance.The hybrid HCS,composed of re-entrant(RE)and elliptical annular re-entrant(EARE)honeycomb cells,was created by constructing arrangement matrices to achieve structural lightweight.The machine learning(ML)framework consisted of a neural network(NN)forward regression model for predicting impact resistance and a multi-objective optimization algorithm for generating high-performance designs.The surrogate of the local design space was initially realized by establishing the NN in the small sample dataset,and the active learning strategy was used to continuously extended the local optimal design until the model converged in the global space.The results indicated that the active learning strategy significantly improved the inference capability of the NN model in unknown design domains.By guiding the iteration direction of the optimization algorithm,lightweight designs with high impact resistance were identified.The energy absorption capacity of the optimal design reached 94.98%of the EARE honeycomb,while the initial peak stress and mass decreased by 28.85%and 19.91%,respectively.Furthermore,Shapley Additive Explanations(SHAP)for global explanation of the NN indicated a strong correlation between the arrangement mode of HCS and its impact resistance.By reducing the stiffness of the cells at the top boundary of the structure,the initial impact damage sustained by the structure can be significantly improved.Overall,this study proposed a general lightweight design method for array structures under impact loads,which is beneficial for the widespread application of honeycomb-based protective structures.
基金funded High-Level Talents project of Henan Agricultural University(111-30501301)Project of the National key R&D Program of China(2021YFA0909600)+3 种基金Natural Science Foundation of Henan Province(242300420141)the China Postdoctoral Science Foundation(2020M672308)Cultivation Program for Young Backbone Teachers at Henan University of Technology(DC 11)Science Project 110202101042(JY 19)/2022530000241007,110202102033,110202202038.
文摘Carotenoid cleavage dioxygenase 4(CCD4)controls the rate-limiting step ofβ-ionone biosynthesis,making it a valuable target for healthcare and pharmaceutical applications.Nicotiana tabacum,a carotenoid-richd crop species,is a promising source forβ-ionone production.This study aimed to modify CCD4 activity to increaseβ-ionone yield in tobacco.We identified two isoforms of CCD4 in N.tabacum,NtCCD4a and NtCCD4b,with NtCCD4a exhibiting significantly higher expression levels than NtCCD4b.Using solid-phase microextraction gas chromatography-mass spectrometry(SPME-GC–MS),we demonstrated that NtCCD4a effectively catalyzes the cleavage ofβ-carotene to produceβ-ionone.To improve its enzymatic activity,we applied structure-based rational design to reconstruct the active pocket of NtCCD4a,followed by high-throughput screening of mutant variants.Three single base mutants,F181G,F184L,and F337M,in NtCCD4a showed enhancedβ-ionone production compared to the wild-type,with F337M yielding the highest amount.No synergistic effects were observed among the three mutants.Transgenic tobacco plants expressing the F181G,F184L,and F337M mutations had acceleratedβ-carotene cleavage and increasedβ-ionone production relative to the wild-type NtCCD4a.Our results establish a framework for the design of CCD4 in major crop species through genome editing technology.
基金supported by the funds of the Ministry of Science and Technology of China(2019YFA0904700)the National Natural Science Foundation of China(32471477)to Cheng Qi.
文摘Biological nitrogen fixation(BNF)and photosynthetic carbon fixation underpin food production and climate mitigation,yet natural systems are constrained by oxygen sensitivity,high energy demand,and inefficient catalysts.This review synthesizes advances that recast these processes as engineering targets and proposes a conceptual roadmap that bridges synthetic symbioses with the synthetic biology of enzymes and pathways.For BNF,progress spans cross-kingdom strategies—from refactoring nif gene sets and targeting nitrogenase assembly to eukaryotic organelles,to engineering plant-associated diazotrophs,rhizosphere control circuits,and emerging nodule-like microenvironments.For carbon assimilation,new-to-nature CO_(2)-fixation modules and photorespiratory bypasses illustrate how pathway redesign and alternative carboxylases can circumvent key Calvin–Benson–Bassham limitations,and expanding photosynthetic light capture offers additional leverage.Across these domains,we extract common design principles:(i)nitrogenase output is increasingly governed by carbon/energy supply and electron delivery as much as by oxygen protection;(ii)robust function requires compartment-aware enzyme–chassis coordination,substrate channeling,and dynamic regulation using sensors and control circuits;and(iii)scalable implementation may benefit from distributing metabolic labor across engineered consortia rather than forcing all functions into a single host.We discuss enabling technologies—including AI-guided protein design and directed evolution,cell-free prototyping,chassis toolkits,and materials/bioelectrochemical interfaces—that can accelerate design–build–test–learn cycles and reduce barriers to deployment.Together,these insights define a path toward integrated nitrogen and carbon fixation systems for low-emission agriculture and biomanufacturing.
基金Support by National Natural Science Foundation of China(22127802,22573091)the HY Action(62402010305)。
文摘Biomass-based hydrocarbon fuels,as one of the alternatives to traditional fossil fuels,have attracted considerable attention in the energy field due to their renewability and environmental benefits.This article provides a systematic review of recent research progress in the chemical synthesis of biomass-based hydrocarbon fuels.It outlines the conversion pathways using feedstocks such as lipids,terpenoids,cellulose/hemicellulose,and lignin.Depending on the feedstock,various products with distinct structural characteristics can be prepared through reactions such as cyclization,condensation,and catalytic hydrogenation.Throughout the synthesis process,three key factors play a critical role:efficient catalyst development,production process optimization,and computational-chemistry-based molecular design.Finally,the article discusses future perspectives for biomass-based hydrocarbon fuel synthesis research.
文摘Filters,as a key component in the photoelectric detection system,can simplify the optical system and improve detection efficiency.Based on the usage requirements,a visible/near-infrared filter film with up to 5 wavebands needs to be designed and prepared,while simultaneously satisfying high reflection in 2 wave-bands and high transmittance in 3 wavebands.Therefore,we have conducted a systematic study on the film design,thin film preparation process,and control accuracy of film layer thickness.In this work,the short-wave pass film system is superimposed with the long-wave pass film system,and the number of cycles and matching coefficient of the film system are tuned to meet the requirements of cut-off band.Additionally,Smith method was used to match bandpass film system to optimize the transmission band and complete the visible/near infrared multiband laser filter film design.In the preparation process,combined with the sensitiv-ity of the film layer,inverse analysis is used to invert the film layer monitored by each optical monitoring chip.The optical control scheme with weak optical signal in the monitoring process is simulated and correc-ted,and the monitoring wavelength with stronger optical signal is matched,resulting in an improvement of the control accuracy for the film thickness and the transmittance in the specified wavelength range.Ulti-mately,the actual physical thickness is 9.66μm,and the error with the theoretical design thickness is less than 0.4%,and the transmittance of the specified 3 wavebands exceeds 99%.The average transmittance of the cut-off bands at the 455−500 nm and 910−1000 nm is 0.45% and 0.16%,respectively.
基金Supported by the National Key Research and Development Program of China(2023YFB4104500,2023YFB4104502)the National Natural Science Foundation of China(22138013)the Taishan Scholar Project(ts201712020).
文摘Against the backdrop of escalating global climate change and energy crises,the resource utilization of carbon dioxide(CO_(2)),a major greenhouse gas,has become a crucial pathway for achieving carbon peaking and carbon neutrality goals.The hydrogenation of CO_(2)to methanol not only enables carbon sequestration and recycling,but also provides a route to produce high value-added fuels and basic chemical feedstocks,holding significant environmental and economic potential.However,this conversion process is thermodynamically and kinetically limited,and traditional catalyst systems(e.g.,Cu/ZnO/Al_(2)O_(3))exhibit inadequate activity,selectivity,and stability under mild conditions.Therefore,the development of novel high-performance catalysts with precisely tunable structures and functionalities is imperative.Metal-organic frameworks(MOFs),as crystalline porous materials with high surface area,tunable pore structures,and diverse metal-ligand compositions,have the great potential in CO_(2)hydrogenation catalysis.Their structural design flexibility allows for the construction of well-dispersed active sites,tailored electronic environments,and enhanced metal-support interactions.This review systematically summarizes the recent advances in MOF-based and MOF-derived catalysts for CO_(2)hydrogenation to methanol,focusing on four design strategies:(1)spatial confinement and in situ construction,(2)defect engineering and ion-exchange,(3)bimetallic synergy and hybrid structure design,and(4)MOF-derived nanomaterial synthesis.These approaches significantly improve CO_(2)conversion and methanol selectivity by optimizing metal dispersion,interfacial structures,and reaction pathways.The reaction mechanism is further explored by focusing on the three main reaction pathways:the formate pathway(HCOO*),the RWGS(Reverse Water Gas Shift reaction)+CO*hydrogenation pathway,and the trans-COOH pathway.In situ spectroscopic studies and density functional theory(DFT)calculations elucidate the formation and transformation of key intermediates,as well as the roles of active sites,metal-support interfaces,oxygen vacancies,and promoters.Additionally,representative catalytic performance data for MOFbased systems are compiled and compared,demonstrating their advantages over traditional catalysts in terms of CO_(2)conversion,methanol selectivity,and space-time yield.Future perspectives for MOF-based CO_(2)hydrogenation catalysts will prioritize two main directions:structural design and mechanistic understanding.The precise construction of active sites through multi-metallic synergy,defect engineering,and interfacial electronic modulation should be made to enhance catalyst selectivity and stability.In addition,advanced in situ characterization techniques combined with theoretical modeling are essential to unravel the detailed reaction mechanisms and intermediate behaviors,thereby guiding rational catalyst design.Moreover,to enable industrial application,challenges related to thermal/hydrothermal stability,catalyst recyclability,and cost-effective large-scale synthesis must be addressed.The development of green,scalable preparation methods and the integration of MOF catalysts into practical reaction systems(e.g.,flow reactors)will be crucial for bridging the gap between laboratory research and commercial deployment.Ultimately,multi-scale structure-performance optimization and catalytic system integration will be vital for accelerating the industrialization of MOF-based CO_(2)-to-methanol technologies.
文摘Evaluating Adherence to Safety Standards for Physical Space Design, Equipment, and Patient and Staff Protection in Magnetic Resonance Imaging Centers:A Descriptive Cross-sectional Study Amirreza Sadeghinasab1, Jafar Fatahiasl2, Mahmoud Mohammadi-Sadr1, Masoud Heydari Kahkesh3, and Marziyeh Tahmasbi2(1.Department of Medical Physics, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran;2.Department of Radiologic Technology, School of Allied Medical Sciences, Ahvaz, Jundishapur University of Medical Sciences, Ahvaz, Iran;3.Department of Radiology and Radiotherapy, School of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran)Abstract:Magnetic resonance imaging(MRI) has revolutionized disease diagnosis and treatment.However, the technology poses safety risks, such as exposure to magnetic fields, RF pulses, and cryogens, necessitating strict adherence to safety protocols to protect patients and healthcare workers.
文摘A two-level,quasi-geostrophic long-wave model based on spherical coordinates was developed with the explicit part belonging to a low-order model.However,it includes not only diabatic heating,Ekman fric- tion and mountain distribution,but also parameterized forcing effects of transfer properties of transient eddies. Experiment results showed that,due to the introduction of the parameterization of transfer properties of transient eddies,remarkable improvements on characters of low-order model had been obtained.In addition to its economization in calculation and conciseness in physics as in a low-order model,the long- wave model was shown to describe the energetics and angular momentum balance of the atmosphere much more reasonably,and to present the features of zonal mean westerlies and stationary waves much more correctly than the corresponding low-order model.This kind of long-wave model was therefore regarded as suitable for theoretical research and numerical modelling of some aspects of the general circulation of the atmosphere.
基金supported by the National Key R&D Program of China(2023YFA1507400)the National Natural Science Foundation of China(Grant No.22325805,22441010,22408203)+2 种基金Beijing Natural Science Foundation(Grant No.JQ22003)the Haihe Laboratory of Sustainable Chemical Transformations(24HHWCSS00007)Tsinghua University Dushi Program,and Sinopec Group(PR20232572).
文摘The electrochemical oxidation of biomass-derived platform molecule 5-hydroxymethylfurfural(HMF)represents a crucial pathway for green transformation into high-value chemicals,yet its reaction pathway selectivity,efficiency,and catalyst stability are strongly dependent on the electrolyte pH environment.Under alkaline conditions,high OH−concentration facilitates preferential aldehyde group oxidation and efficient deprotonation,enabling highly efficient synthesis of 2,5-furandicarboxylic acid,but simultaneously induces HMF self-degradation and complicates product separation.As pH decreases,the reaction mechanism shifts toward enhanced hydroxymethyl oxidation,leading to intermediate accumulation(such as 5-hydroxymethyl-2-furancarboxylic acid,2,5-diformylfuran,and 5-formyl-2-furancarboxylic acid)with challenging selectivity control and significantly slowed reaction kinetics.This review comprehensively examines the systematic differences in HMF oxidation pathways and surface catalytic mechanisms across the full pH range from alkaline to acidic conditions.Addressing the distinct reaction characteristics and core challenges in alkaline,near-neutral,and acidic media,we systematically evaluate design strategies for high-efficiency electrocatalysts and explore reactor design aspects.Future research should focus on process integration(with tailored reactor design)for energy consumption reduction in alkaline systems,targeted synthesis of diverse oxidation products in near-neutral systems,and innovative catalyst development for acidic systems,thereby advancing the efficiency,selectivity,and practical application of HMF electrooxidation technologies across the entire pH spectrum through synergistic optimization of catalyst,reactor,and process.
文摘With the rapid growth of cloud computing,the number of data centers(DCs)continuously increases,leading to a high-energy consumption dilemma.Cooling,apart from IT equipment,represents the largest energy consumption in DCs.Passive design(PD)and active design(AD)are two important approaches in architectural design to reduce energy consumption.However,for DC cooling,few studies have summarized AD,and there are almost no studies on PD.Based on existing international research(2005-2024),this paper summarizes the current state of cooling strategies for DCs.PD encompasses floors,ceilings,and layout and zoning of racks.Additionally,other passive strategies not yet studied in DCs are critically examined.AD includes air,liquid,free,and two-phase cooling.This paper systematically compares the performance of different AD technologies on various KPIs,including energy,economic,and environmental indicators.This paper also explores the application of different cooling design strategies through best-practice examples and presents advanced algorithms for energy management in operational DCs.This study reveals that free cooling is widely employed,with Artificial Neural Networks emerging as the most popular algorithm for managing cooling energy.Finally,this paper suggests four future directions for reducing cooling energy in DCs,with a focus on the development of passive strategies.This paper provides an overview and guide to DC energy-consumption issues,emphasizes the importance of implementing passive and active design strategies to reduce DC cooling energy consumption,and provides directions and references for future energy-efficient DC designs.
