The present study was designed to investigate the antithrombotic effects and underlying mechanisms of the effective components group(ECG) of Xiaoshuantongluo recipe(XECG) and to further verify the rationality and feas...The present study was designed to investigate the antithrombotic effects and underlying mechanisms of the effective components group(ECG) of Xiaoshuantongluo recipe(XECG) and to further verify the rationality and feasibility of ECG-guided methodology in traditional Chinese medicine(TCM) research. The arterial thrombosis model induced by ferric chloride(FeC l3) oxidation and the venous thrombosis model induced by inferior vena cava ligation were established to evaluate the antithrombotic potential of XECG. Our results indicated that XECG significantly prolonged the time to occlusion, activated partial thromboplastin time(APTT), and prothrombin time(PT), and markedly inhibited adenosine diphosphate(ADP)-induced platelet aggregation in the 20% Fe Cl3-induced arterial thrombosis model. The superoxide dismutase(SOD) activity was significantly increased and the levels of malondialdehyde(MDA) and nitric oxide(NO) were dramatically decreased in the plasma of arterial thrombosis rats after XECG treatment for 12 days. Furthermore, XECG markedly reduced the weight of thrombus formed by inferior vena cava ligation. Additionally, XECG exhibited 2,2-diphenyl-1-picrylhydrazyl(DPPH) free radical scavenging activity and protective effect on mitochondrial lipid peroxidation. In summary, XECG played an important role in the prevention of thrombosis through interacting with multiple targets, including inhibition of platelet aggregation and coagulation and repression of oxidative stress. The ECG-guided methodology was validated as a feasible tool in TCM research.展开更多
Addressing the pressing challenges of climate change and global warming requires a strong commitment to reducing carbon dioxide(CO_(2))emissions and achieving carbon neutrality.Efficient energy use and international t...Addressing the pressing challenges of climate change and global warming requires a strong commitment to reducing carbon dioxide(CO_(2))emissions and achieving carbon neutrality.Efficient energy use and international trade play crucial roles in promoting sustainable development and enhancing environmental quality.This study investigated the relationships of CO_(2) emissions with trade openness(export and import),energy consumption(renewable energy consumption and fossil fuel consumption),natural resource rents,and human capital across 20 developing countries(Brazil,Iran,Russia,China,Malaysia,Saudi Arabia,Colombia,Mexico,South Africa,Costa Rica,Morocco,Tunisia,Egypt,Pakistan,Türkiye,India,Peru,Viet Nam,Indonesia,and Philippines)from 1990 to 2022 using the augmented mean group(AMG)and common correlated effects mean group(CCEMG)methods.The findings revealed that export,renewable energy consumption,and human capital significantly reduce CO_(2) emissions,while import,fossil fuel consumption,and natural resource rents increase CO_(2) emissions,although the effect of natural resource rents is statistically insignificant.Causality tests indicated the bidirectional relationship of CO_(2) emissions with export,import,renewable energy consumption,and fossil fuel consumption,and the unidirectional causality from human capital to CO_(2) emissions.CO_(2) emissions drive the greenhouse effect,thereby raising global temperature and accelerating climate change.As reducing CO_(2) emissions becomes an urgent global priority,this study provides actionable insights by identifying key variables that mitigate emissions and enhance sustainability.By bridging research and policy,this study offers targeted recommendations to accelerate progress toward a low-carbon future.展开更多
A simple semi-empirical analysis method for predicting the group effect of pile group under dragload embedded in clay was described assuming an effective influence area around various locations of pile group. Various ...A simple semi-empirical analysis method for predicting the group effect of pile group under dragload embedded in clay was described assuming an effective influence area around various locations of pile group. Various pile and soil parameters such as the array of pile group, spacing of the piles (S), embedment length to diameter ratio of piles (L/D) and the soil properties such as density (γ), angle of internal friction (φ) and pile-soil interface friction coefficient (μ) were considered in the analysis. Model test for dragload of pile group on viscosity soil layer under surface load consolidation conditions was studied. The variations of dragload of pile, resistance of pile tip and the layered settlement of soil with consolidation time were measured. In order to perform comparative analysis, single pile was tested in the same conditions. The predicted group effect values of pile group under dragload were then compared with model test results carried out as a part of the present investigation and also with the values reported in literatures. The predicted values were found to be in good agreement with the measured values, validating the developed analysis method. The model test results show that negative skin friction of pile shaft will reach 80%-90% of its maximum value, when pile-soil relative displacement reaches 2 mm.展开更多
This paper aims to present a theoretical method to study the bearing performance of vertically loaded large-diameter pipe pile groups.The interactions between group piles result in different bearing performance of bot...This paper aims to present a theoretical method to study the bearing performance of vertically loaded large-diameter pipe pile groups.The interactions between group piles result in different bearing performance of both a single pile and pile groups.Considering the pile group effect and the skin friction from both outer and inner soils,an analytical solution is developed to calculate the settlement and axial force in large-diameter pipe pile groups.The analytical solution was verified by centrifuge and field testing results.An extensive parametric analysis was performed to study the bearing performance of the pipe pile groups.The results reveal that the axial forces in group piles are not the same.The larger the distance from central pile,the larger the axial force.The axial force in the central pile is the smallest,while that in corner piles is the largest.The axial force on the top of the corner piles decreases while that in the central pile increases with increasing of pile spacing and decreasing of pile length.The axial force in side piles varies little with the variations of pile spacing,pile length,and shear modulus of the soil and is approximately equal to the average load shared by one pile.For a pile group,the larger the pile length is,the larger the influence radius is.As a result,the pile group effect is more apparent for a larger pile length.The settlement of pile groups decreases with increasing of the pile number in the group and the shear modulus of the underlying soil.展开更多
An empirical approach has been developed to analyze the nonlinear response of a pile group with arbitrarily distributed piles subjected to combined lateral and torsional loading.In this approach,the concept of instant...An empirical approach has been developed to analyze the nonlinear response of a pile group with arbitrarily distributed piles subjected to combined lateral and torsional loading.In this approach,the concept of instantaneous twist center is applied to analyze the displacement relationship of pile heads and establish the static equilibrium equations of the pile cap.The horizontal interaction among the individual piles is considered through the generalized p-multiplier.The coupling effect of lateral resistance on the torsional resistance of each pile is quantified using an empirical factorβ;the lateral and torsional nonlinear responses of individual piles are modeled by p-y andτ-θcurves,respectively.The proposed approach not only captures the most significant aspect of the group effect and coupling effect in a pile group subjected to combined lateral and torsional loading,but also automatically updates p-multipliers of individual piles based on pile cap displacements.The proposed approach was verified using results of model tests on pile groups subjected to lateral loading,torsional loading,and combined lateral and torsional loading,separately.In general,the pile cap response and the transfer of applied loads in the pile groups agree well with the test results.展开更多
In this work, we focus on assessing the group effect of localized corrosion on the ultimate strength of the marine structural plates and study the load-deformation behaviors of plates of various slenderness and uniaxi...In this work, we focus on assessing the group effect of localized corrosion on the ultimate strength of the marine structural plates and study the load-deformation behaviors of plates of various slenderness and uniaxial compression.Meanwhile, we investigate different corroded patterns from a single circular pit to 25 circular pits distributed over the plate and carry out hundreds of nonlinear finite element simulations by combining the number, depth, distribution of pits with imperfections and slenderness of plate. The distribution of multiple pits causes scattering of stress concentration on the plate, then the plastic section of plate changes with wider distribution of damage simultaneously. The ultimate strength arises when un-loading zone comprised of the yielding strips and holes extends across the plate. It can be concluded that the corroded condition defined as group effect of pits manipulates the deformation state and the loading capacity of plate at the ultimate strength mode that coincides with the proportion of effective loading area and section in the process of post-buckling. To validate the effect of pits group, we perform the numerical experiments of the post-buckling of steel plates containing pits in a row with different orientation.展开更多
Vigilance behavior is considered as an effective strategy for prey species to detect predators.An individual benefits from living in a group by reducing the time spent being vigilant without affecting the probability ...Vigilance behavior is considered as an effective strategy for prey species to detect predators.An individual benefits from living in a group by reducing the time spent being vigilant without affecting the probability of detecting a predator.However,the mechanism producing a decrease in vigilance with increasing group size is unclear.Many models of vigilance assume that group members scan independently of one another.Yet in recent studies,the other 2 patterns of vigilance,coordination and synchronization,were reported in some species.In 2 summers(2018 and 2019),we studied the group-size effect on vigilance and foraging of Tibetan wild ass in Chang Tang Nature Reserve of Tibet.We also tested whether individuals scan the environment independently,tend to coordinate their scans,or tend to synchronize their vigilance.The results showed that individuals decreased the time spent on vigilance with increasing group size,while increased the time spent foraging.Group members scanned the environment at the same time more frequently and there was a positive correlation between group members'behaviors,indicating that Tibetan wild asses tend to synchronize their vigilance.展开更多
The interfacial defects and energy barrier are main reasons for interfacial nonradiative recombination.In addition,poor perovskite crystallization and incomplete conversion of PbI_(2) to perovskite restrict further en...The interfacial defects and energy barrier are main reasons for interfacial nonradiative recombination.In addition,poor perovskite crystallization and incomplete conversion of PbI_(2) to perovskite restrict further enhancement of the photovoltaic performance of the devices using sequential deposition.Herein,a buried interface stabilization strategy that relies on the synergy of fluorine(F)and sulfonyl(S=O)functional groups is proposed.A series of potassium salts containing halide and non-halogen anions are employed to modify SnO_(2)/perovskite buried interface.Multiple chemical bonds including hydrogen bond,coordination bond and ionic bond are realized,which strengthens interfacial contact and defect passivation effect.The chemical interaction between modification molecules and perovskite along with SnO_(2) heightens incessantly as the number of S=O and F augments.The chemical interaction strength between modifiers and perovskite as well as SnO_(2) gradually increases with the increase in the number of S=O and F.The defect passivation effect is positively correlated with the chemical interaction strength.The crystallization kinetics is regulated through the compromise between chemical interaction strength and wettability of substrates.Compared with Cl−,all non-halogen anions perform better in crystallization optimization,energy band regulation and defect passivation.The device with potassium bis(fluorosulfonyl)imide achieves a tempting efficiency of 24.17%.展开更多
The European Union(EU) and Organisation for Economic Co-operation and Development(OECD) aim to develop long-term policies for their respective member countries. Having observed increasing dangers to the environment po...The European Union(EU) and Organisation for Economic Co-operation and Development(OECD) aim to develop long-term policies for their respective member countries. Having observed increasing dangers to the environment posed by rising economic growth, they are seeking pathways to enable policy action on economic growth and environmental sustainability. Given the facts in theoretical and empirical studies, this study assessed the validity of the decoupling hypothesis by investigating asymmetricity in the relationship between environmental sustainability and economic growth in nine Eastern European countries from 1998 to 2017 using the cross-section augmented Dickey-Fuller(CADF) unit root, panel corrected standard error(PCSE), common correlated effect mean group(CCEMG), and Dumitrescu Hurlin causality approaches. Both population growth and drinking water are used as controlled variables. The outcomes establish strong cointegration among all the variables of interest. According to the results of CCEMG test, economic growth exerts short-term environmental degradation but has long-term environmental benefits in Eastern Europe;and population growth and drinking water exert a positive effect on environmental sustainability in both the short-and long-run. The results of Dumitrescu Hurlin causality test indicate that environmental sustainability is unidirectionally affected by economic growth. Based on these outcomes, we suggest the following policies:(1) the EU and OECD should implement member-targeted policies on economic growth and fossil-fuel use towards regulating industrial pollution, water use, and population control;and(2) the EU and OECD member countries should invest in environmental technologies through green research and development(R&D) to transform their dirty industrial processes and ensure productive energy use.展开更多
This paper aims to study the mathematical properties of the l vmodels that employ measurement matrices with correlated columns.We first show that the l_(1-2)model satisfies the grouping effect which ensures that coeff...This paper aims to study the mathematical properties of the l vmodels that employ measurement matrices with correlated columns.We first show that the l_(1-2)model satisfies the grouping effect which ensures that coefficients corresponding to highly correlated columns in a measurement matrix have small differences.Then we provide the stability analysis based on the sparse approximation property.When the entries of the vectors have different signs,we show that the grouping effect also holds for the constraint l_(1-2)minimization model which is implicated by the linearized Bregman iteration.展开更多
The Wilsonian renormalization group approach to the Lippmann-Schwinger equation with a multitude of cutoff parameters is introduced.A system of integro-differential equations for the cutoff-dependent potential is obta...The Wilsonian renormalization group approach to the Lippmann-Schwinger equation with a multitude of cutoff parameters is introduced.A system of integro-differential equations for the cutoff-dependent potential is obtained.As an illustration,a perturbative solution of these equations with two cutoff parameters for a simple case of an S-wave low-energy potential in the form of a Taylor series in momenta is obtained.The relevance of the obtained results for the effective field theory approach to nucleon-nucleon scattering is discussed.展开更多
With the hypothesis of simple units integration to create new reactivities,a strategy for the synthesis of polyfunctionalized 5-alkenyl-3-carbonylfurans fromγ-hydroxyl enal and 1,3-dicarbonyl compounds is established...With the hypothesis of simple units integration to create new reactivities,a strategy for the synthesis of polyfunctionalized 5-alkenyl-3-carbonylfurans fromγ-hydroxyl enal and 1,3-dicarbonyl compounds is established,featuring readily available starting materials,high efficiency,good functional groups compatibility,green chemistry with high atom economy and only water release,etc.,to provide a series of polyfunctionalized 5-alkenyl-3-carbonylfurans,which could be applied to the late-stage functionalization of naturally occurring compounds and bioactive molecules,as well as the transformation to pyrroles and polycyclic aromatic hydrocarbon via electrocyclic reaction.Theγ-hydroxyl has played an important role in the unexpected process of ring opening isomerization of 2H-pyran to furanones,as confirmed by detailed mechanistic studies.展开更多
This paper is devoted to identifying the biomarkers of rat liver regeneration via the adaptive logistic regression. By combining the adaptive elastic net penalty with the logistic regression loss, the adaptive logisti...This paper is devoted to identifying the biomarkers of rat liver regeneration via the adaptive logistic regression. By combining the adaptive elastic net penalty with the logistic regression loss, the adaptive logistic regression is proposed to adaptively identify the important genes in groups. Furthermore, by improving the pathwise coordinate descent algorithm, a fast solving algorithm is developed for computing the regularized paths of the adaptive logistic regression. The results from the experiments performed on the microarray data of rat liver regeneration are provided to illustrate the effectiveness of the proposed method and verify the biological rationality of the selected biomarkers.展开更多
The defects from electron transport layer,perovskite layer and their interface would result in carrier nonradiative recombination losses.Poor buried interfacial contact is detrimental to charge extraction and device s...The defects from electron transport layer,perovskite layer and their interface would result in carrier nonradiative recombination losses.Poor buried interfacial contact is detrimental to charge extraction and device stability.Here,we report a bottom-up holistic carrier management strategy induced synergistically by multiple chemical bonds to minimize bulk and interfacial energy losses for high-performance perovskite photovoltaics.4-trifluoromethyl-benzamidine hydrochloride(TBHCl)containing–CF_(3),amidine cation and Cl^(-)is in advance incorporated into SnO_(2)colloid solution to realize bottom-up modification.The synergistic effect of multiple functional groups and multiple-bond-induced chemical interaction are revealed theoretically and experimentally.F and Cl^(-)can passivate oxygen vacancy and/or undercoordinated Sn^(4+)defects by coordinating with Sn^(4+).The F can suppress cation migration and modulate crystallization via hydrogen bond with FA^(+),and can passivate lead defects by coordinating with Pb^(2+).The–NH_(2)–C=NH^(+)_(2)and Cl^(-)can passivate cation and anion vacancy defects through ionic bonds with perovskites,respectively.Through TBHCl modification,the suppression of agglomeration of SnO_(2)nanoparticles,bulk and interfacial defect passivation,and release of tensile strains of perovskite films are demonstrated,which resulted in a PCE enhancement from 21.28%to 23.40%and improved stability.With post-treatment,the efficiency is further improved to 23.63%.展开更多
OBJECTIVE To investigate the cerebralvasorelaxant material basis of Xiaoxuming decoction.METHODS According to the Xiaoxuming decoction herb sources,we retrieved the chemical structure from the literatures and the Chin...OBJECTIVE To investigate the cerebralvasorelaxant material basis of Xiaoxuming decoction.METHODS According to the Xiaoxuming decoction herb sources,we retrieved the chemical structure from the literatures and the Chinese Natural Product Database(http://pharmdata.ncmi.cn).By using microvessel tension system,we checked the vasorelaxanteffects of Xiaoxuming decoction anti-cerebral ischemia effective components group(XXMDECG)and the available composition compounds on pre-contracted basilar artery ring.RESULTS963 compoundsin the decoction,including 81Fangfeng,77 Mahuang,130 Shengjiang,31 Guizhi,91 Huangqin,127 Renshen,73 Chuanxiong,44 Shaoyao,39 Xingren,42 Fangji,62 Fuzi and 166 Gancao were collected.The five largest number classes of compounds in the decoction are volatile oil(32%),flavone(32%),alkaloid(13%),saponin(7%),polyphenol and organic acid(5%).XXMDECG at concentration from 1 to 400μg·mL-1can dilate the KCl(60 mmol·L-1)and ET-1(0.01μmol·L-1)pre-contracted rat basilar artery rings in a dose-dependent manner.There are 6 compounds with vasorelaxant ratio more than 50%at the concentration of 10μmol·L-1.CONCLUSION Xiaoxuming decoction contains abundant chemical structure.It has the material basis of multiple ingredients and multiple targets.The XXMDECG are able to dilate the rat basilar artery rings in a dose-dependent manner.The network interactions between varies of chemical compounds in Xiaoxuming decoction and the vasoconstriction associated targets result in the comprehensive regulation mechanisms of vascular function.展开更多
Considering the high sensitivity of the nonlinear ultrasonic measurement technique and great advantages of the guided wave testing method, the use of nonlinear ultrasonic guided waves provides a promising means for ev...Considering the high sensitivity of the nonlinear ultrasonic measurement technique and great advantages of the guided wave testing method, the use of nonlinear ultrasonic guided waves provides a promising means for evaluating and characterizing the hidden and/or inaccessible damage/degradation in solid media. Increasing attention on the development of the testing method based on nonlinear ultrasonic guided waves is largely attributed to the theoretical advances of nonlinear guided waves propagation in solid media. One of the typical acoustic nonlinear responses is the generation of second harmonics that can be used to effectively evaluate damage/degradation in materials/structures. In this paper, the theoretical progress of second-harmonic generation（SHG） of ultrasonic guided wave propagation in solid media is reviewed. The advances and developments of theoretical investigations on the effect of SHG of ultrasonic guided wave propagation in different structures are addressed. Some obscure understandings and the ideas in dispute are also discussed.展开更多
In an attempt to clarify issues related to the molecular weight dependence of the phase transition of poly(N-isopropylacrylamide) (PNIPAM) in water,we prepared a library of PNIPAM samples of well-controlled molecular ...In an attempt to clarify issues related to the molecular weight dependence of the phase transition of poly(N-isopropylacrylamide) (PNIPAM) in water,we prepared a library of PNIPAM samples of well-controlled molecular weight (7000 to 45000 g/mol) bearing identical groups on each chain end.The polymers were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization of N-isopropylacrylamide (NIPAM) with a bifunctional chain tranfer agent and further end group modification.The effects of the end group chemical structure,hydroxyethyl (HE),propargyl (Pr),chloroethyl (CE),n-butyl (nBu),n-hexyl (nHe),and isobutylsulfanylthiosulfanyl (IBS) on the phase transition temperature of aqueous PNIPAM solutions were investigated by high-sensitivity differential scanning calorimetry (HS-DSC),yielding the enthalpy ΔH and the endotherm maximum temperature (T M),and turbidimetry,providing the cloud point (T CP) of each solution.The T CP and T M of the PNIPAM sample of lowest molar mass (M n 7,000 g/mol,0.5 g/L) ranged,respectively,from 38.8 to 22.5 °C and 42.2 to 26.0 °C,depending on the structure of the end-group,whereas H showed no strong end-group dependence.The phase transition of all polymers,except,-di(n-butyl-PNIPAM),exhibited a marked dependence on the polymer molar mass.展开更多
Variable selection plays an important role in high-dimensional data analysis.But the high-dimensional data often induces the strongly correlated variables problem,which should be properly handled.In this paper,we prop...Variable selection plays an important role in high-dimensional data analysis.But the high-dimensional data often induces the strongly correlated variables problem,which should be properly handled.In this paper,we propose Elastic Net procedure for partially linear models and prove the group effect of its estimate.A simulation study shows that the Elastic Net procedure deals with the strongly correlated variables problem better than the Lasso,ALasso and the Ridge do.Based on the real world data study,we can get that the Elastic Net procedure is particularly useful when the number of predictors pffis much bigger than the sample size n.展开更多
It is observed that the regulation sequences at the two ends of every active gene of the heart nuclear DNA fragments may differentially combine with active regulation factors such as some specific binding proteins by ...It is observed that the regulation sequences at the two ends of every active gene of the heart nuclear DNA fragments may differentially combine with active regulation factors such as some specific binding proteins by using AFM and other experimental technologies. These active genes form different "gene knots", which are separated by "intervals". Using AFM, occasionally, it is also discovered that during the transcription stage, the heart nuclear DNA fragments consist of 3 4 5 "gene knots" and related "intervals", which form various "gene lineages" respectively by some "permutation and combination". Each gene lineage is likely to form nRNA chain like complexes that are 3 times the quantity of gene knots, and each nRNA chain like complex is connected with both ends of corresponding gene lineage. One gene knot of the DNA fragments participates the formation of different gene lineage and corresponding RNA chain like complexes by different combination. By posttranscriptional modification, they can form nmRNA linear chain like complexes that show the speciality of tissues. The beginnings of transcription units have the same number as gene lineages, and all gene lineages in DNA molecules may transcribe efficiently from corresponding beginnings of transcription unit simultaneously. Our work shows the prospective application of AFM in the research of the diversity of gene lineages formation from gene knots in the transcription stage and the efficiency of gene knots transcription.展开更多
Using AFM,we observed linear chain-like complexes formed by some specific proteins and the multi-mRNAs during the in vitro expression of some active genes on the DNA fragments. The LDH mRNA in the multi-mRNA complex c...Using AFM,we observed linear chain-like complexes formed by some specific proteins and the multi-mRNAs during the in vitro expression of some active genes on the DNA fragments. The LDH mRNA in the multi-mRNA complex can in vitro translate LDH. Via AFM, we also discovered that nmRNA prepared from heart muscles, along with some specific proteins can form linear chain-like nmRNA complexes in which LDH mRNA can also translate LDH in vitro. Our work shows the prospective application of AFM in the research of the biological reaction of the active genes on the DNA fragments.展开更多
基金supported by the Major Scientific and Technological Special Project for"Significant New Drugs Creation"(No.2013ZX09508104001002)the National Natural Science Foundation of China(No.81273652)
文摘The present study was designed to investigate the antithrombotic effects and underlying mechanisms of the effective components group(ECG) of Xiaoshuantongluo recipe(XECG) and to further verify the rationality and feasibility of ECG-guided methodology in traditional Chinese medicine(TCM) research. The arterial thrombosis model induced by ferric chloride(FeC l3) oxidation and the venous thrombosis model induced by inferior vena cava ligation were established to evaluate the antithrombotic potential of XECG. Our results indicated that XECG significantly prolonged the time to occlusion, activated partial thromboplastin time(APTT), and prothrombin time(PT), and markedly inhibited adenosine diphosphate(ADP)-induced platelet aggregation in the 20% Fe Cl3-induced arterial thrombosis model. The superoxide dismutase(SOD) activity was significantly increased and the levels of malondialdehyde(MDA) and nitric oxide(NO) were dramatically decreased in the plasma of arterial thrombosis rats after XECG treatment for 12 days. Furthermore, XECG markedly reduced the weight of thrombus formed by inferior vena cava ligation. Additionally, XECG exhibited 2,2-diphenyl-1-picrylhydrazyl(DPPH) free radical scavenging activity and protective effect on mitochondrial lipid peroxidation. In summary, XECG played an important role in the prevention of thrombosis through interacting with multiple targets, including inhibition of platelet aggregation and coagulation and repression of oxidative stress. The ECG-guided methodology was validated as a feasible tool in TCM research.
基金support from the Philosophy and Social Sciences Excellent Innovation Team Construction Foundation of Jiangsu Province China(SJSZ2020-20).
文摘Addressing the pressing challenges of climate change and global warming requires a strong commitment to reducing carbon dioxide(CO_(2))emissions and achieving carbon neutrality.Efficient energy use and international trade play crucial roles in promoting sustainable development and enhancing environmental quality.This study investigated the relationships of CO_(2) emissions with trade openness(export and import),energy consumption(renewable energy consumption and fossil fuel consumption),natural resource rents,and human capital across 20 developing countries(Brazil,Iran,Russia,China,Malaysia,Saudi Arabia,Colombia,Mexico,South Africa,Costa Rica,Morocco,Tunisia,Egypt,Pakistan,Türkiye,India,Peru,Viet Nam,Indonesia,and Philippines)from 1990 to 2022 using the augmented mean group(AMG)and common correlated effects mean group(CCEMG)methods.The findings revealed that export,renewable energy consumption,and human capital significantly reduce CO_(2) emissions,while import,fossil fuel consumption,and natural resource rents increase CO_(2) emissions,although the effect of natural resource rents is statistically insignificant.Causality tests indicated the bidirectional relationship of CO_(2) emissions with export,import,renewable energy consumption,and fossil fuel consumption,and the unidirectional causality from human capital to CO_(2) emissions.CO_(2) emissions drive the greenhouse effect,thereby raising global temperature and accelerating climate change.As reducing CO_(2) emissions becomes an urgent global priority,this study provides actionable insights by identifying key variables that mitigate emissions and enhance sustainability.By bridging research and policy,this study offers targeted recommendations to accelerate progress toward a low-carbon future.
基金Project(50679015) supported by the National Natural Science Foundation of China
文摘A simple semi-empirical analysis method for predicting the group effect of pile group under dragload embedded in clay was described assuming an effective influence area around various locations of pile group. Various pile and soil parameters such as the array of pile group, spacing of the piles (S), embedment length to diameter ratio of piles (L/D) and the soil properties such as density (γ), angle of internal friction (φ) and pile-soil interface friction coefficient (μ) were considered in the analysis. Model test for dragload of pile group on viscosity soil layer under surface load consolidation conditions was studied. The variations of dragload of pile, resistance of pile tip and the layered settlement of soil with consolidation time were measured. In order to perform comparative analysis, single pile was tested in the same conditions. The predicted group effect values of pile group under dragload were then compared with model test results carried out as a part of the present investigation and also with the values reported in literatures. The predicted values were found to be in good agreement with the measured values, validating the developed analysis method. The model test results show that negative skin friction of pile shaft will reach 80%-90% of its maximum value, when pile-soil relative displacement reaches 2 mm.
基金supported by the Joint High Speed Railway Key Program of National Natural Science Foundation of China (Grant No.U1134207)the National Natural Science Foundation of China (Grant No.51378177)+1 种基金the Program for Excellent University Talents in New Century (Grant No.NCET-12-0843)the Fundamental Research Fund for the Central Universities (Grant No.106112014CDJZR200007)
文摘This paper aims to present a theoretical method to study the bearing performance of vertically loaded large-diameter pipe pile groups.The interactions between group piles result in different bearing performance of both a single pile and pile groups.Considering the pile group effect and the skin friction from both outer and inner soils,an analytical solution is developed to calculate the settlement and axial force in large-diameter pipe pile groups.The analytical solution was verified by centrifuge and field testing results.An extensive parametric analysis was performed to study the bearing performance of the pipe pile groups.The results reveal that the axial forces in group piles are not the same.The larger the distance from central pile,the larger the axial force.The axial force in the central pile is the smallest,while that in corner piles is the largest.The axial force on the top of the corner piles decreases while that in the central pile increases with increasing of pile spacing and decreasing of pile length.The axial force in side piles varies little with the variations of pile spacing,pile length,and shear modulus of the soil and is approximately equal to the average load shared by one pile.For a pile group,the larger the pile length is,the larger the influence radius is.As a result,the pile group effect is more apparent for a larger pile length.The settlement of pile groups decreases with increasing of the pile number in the group and the shear modulus of the underlying soil.
基金Project supported by the National Natural Science Foundation of China(Nos.50809060 and 51579218)the Fundamental Research Funds for the Central Universities,China(No.2011QNA4013)。
文摘An empirical approach has been developed to analyze the nonlinear response of a pile group with arbitrarily distributed piles subjected to combined lateral and torsional loading.In this approach,the concept of instantaneous twist center is applied to analyze the displacement relationship of pile heads and establish the static equilibrium equations of the pile cap.The horizontal interaction among the individual piles is considered through the generalized p-multiplier.The coupling effect of lateral resistance on the torsional resistance of each pile is quantified using an empirical factorβ;the lateral and torsional nonlinear responses of individual piles are modeled by p-y andτ-θcurves,respectively.The proposed approach not only captures the most significant aspect of the group effect and coupling effect in a pile group subjected to combined lateral and torsional loading,but also automatically updates p-multipliers of individual piles based on pile cap displacements.The proposed approach was verified using results of model tests on pile groups subjected to lateral loading,torsional loading,and combined lateral and torsional loading,separately.In general,the pile cap response and the transfer of applied loads in the pile groups agree well with the test results.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51490670 and 11572300)R&D Plan(Grant No.2017GHY15120)Fundamental Research Fund for Central Universities(Ocean University of China)
文摘In this work, we focus on assessing the group effect of localized corrosion on the ultimate strength of the marine structural plates and study the load-deformation behaviors of plates of various slenderness and uniaxial compression.Meanwhile, we investigate different corroded patterns from a single circular pit to 25 circular pits distributed over the plate and carry out hundreds of nonlinear finite element simulations by combining the number, depth, distribution of pits with imperfections and slenderness of plate. The distribution of multiple pits causes scattering of stress concentration on the plate, then the plastic section of plate changes with wider distribution of damage simultaneously. The ultimate strength arises when un-loading zone comprised of the yielding strips and holes extends across the plate. It can be concluded that the corroded condition defined as group effect of pits manipulates the deformation state and the loading capacity of plate at the ultimate strength mode that coincides with the proportion of effective loading area and section in the process of post-buckling. To validate the effect of pits group, we perform the numerical experiments of the post-buckling of steel plates containing pits in a row with different orientation.
基金This work was supported by National Natural Science Foundation of China(31772470,41871294)Tibet Major Science and Technology Project(XZ201901-GA-06).
文摘Vigilance behavior is considered as an effective strategy for prey species to detect predators.An individual benefits from living in a group by reducing the time spent being vigilant without affecting the probability of detecting a predator.However,the mechanism producing a decrease in vigilance with increasing group size is unclear.Many models of vigilance assume that group members scan independently of one another.Yet in recent studies,the other 2 patterns of vigilance,coordination and synchronization,were reported in some species.In 2 summers(2018 and 2019),we studied the group-size effect on vigilance and foraging of Tibetan wild ass in Chang Tang Nature Reserve of Tibet.We also tested whether individuals scan the environment independently,tend to coordinate their scans,or tend to synchronize their vigilance.The results showed that individuals decreased the time spent on vigilance with increasing group size,while increased the time spent foraging.Group members scanned the environment at the same time more frequently and there was a positive correlation between group members'behaviors,indicating that Tibetan wild asses tend to synchronize their vigilance.
基金supported by the Defense Industrial Technology Development Program(JCKY2017110C0654)National Natural Science Foundation of China(11974063,61904023,62274018)+1 种基金Chongqing Special Postdoctoral Science Foundation(cstc2019jcyj-bsh0026)Fundamental Research Funds for the Central Universities(2021CDJQY-022).
文摘The interfacial defects and energy barrier are main reasons for interfacial nonradiative recombination.In addition,poor perovskite crystallization and incomplete conversion of PbI_(2) to perovskite restrict further enhancement of the photovoltaic performance of the devices using sequential deposition.Herein,a buried interface stabilization strategy that relies on the synergy of fluorine(F)and sulfonyl(S=O)functional groups is proposed.A series of potassium salts containing halide and non-halogen anions are employed to modify SnO_(2)/perovskite buried interface.Multiple chemical bonds including hydrogen bond,coordination bond and ionic bond are realized,which strengthens interfacial contact and defect passivation effect.The chemical interaction between modification molecules and perovskite along with SnO_(2) heightens incessantly as the number of S=O and F augments.The chemical interaction strength between modifiers and perovskite as well as SnO_(2) gradually increases with the increase in the number of S=O and F.The defect passivation effect is positively correlated with the chemical interaction strength.The crystallization kinetics is regulated through the compromise between chemical interaction strength and wettability of substrates.Compared with Cl−,all non-halogen anions perform better in crystallization optimization,energy band regulation and defect passivation.The device with potassium bis(fluorosulfonyl)imide achieves a tempting efficiency of 24.17%.
文摘The European Union(EU) and Organisation for Economic Co-operation and Development(OECD) aim to develop long-term policies for their respective member countries. Having observed increasing dangers to the environment posed by rising economic growth, they are seeking pathways to enable policy action on economic growth and environmental sustainability. Given the facts in theoretical and empirical studies, this study assessed the validity of the decoupling hypothesis by investigating asymmetricity in the relationship between environmental sustainability and economic growth in nine Eastern European countries from 1998 to 2017 using the cross-section augmented Dickey-Fuller(CADF) unit root, panel corrected standard error(PCSE), common correlated effect mean group(CCEMG), and Dumitrescu Hurlin causality approaches. Both population growth and drinking water are used as controlled variables. The outcomes establish strong cointegration among all the variables of interest. According to the results of CCEMG test, economic growth exerts short-term environmental degradation but has long-term environmental benefits in Eastern Europe;and population growth and drinking water exert a positive effect on environmental sustainability in both the short-and long-run. The results of Dumitrescu Hurlin causality test indicate that environmental sustainability is unidirectionally affected by economic growth. Based on these outcomes, we suggest the following policies:(1) the EU and OECD should implement member-targeted policies on economic growth and fossil-fuel use towards regulating industrial pollution, water use, and population control;and(2) the EU and OECD member countries should invest in environmental technologies through green research and development(R&D) to transform their dirty industrial processes and ensure productive energy use.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(LR19A010001)the NSF of China(12022112)Research of Hu Ruifang was supported by the general research project of Jiaxing Nanhu University(62107YL)。
文摘This paper aims to study the mathematical properties of the l vmodels that employ measurement matrices with correlated columns.We first show that the l_(1-2)model satisfies the grouping effect which ensures that coefficients corresponding to highly correlated columns in a measurement matrix have small differences.Then we provide the stability analysis based on the sparse approximation property.When the entries of the vectors have different signs,we show that the grouping effect also holds for the constraint l_(1-2)minimization model which is implicated by the linearized Bregman iteration.
基金Supported in part by BMBF under Grant No.05P2015–NUSTAR R&D)DFG and NSFC through Funds Provided to the SinoGerman CRC 110 “Symmetries and the Emergence of Structure in QCD”+2 种基金National Natural Science Foundation of China under Grant No.11621131001,DFG Grant No.TRR110the Georgian Shota Rustaveli National Science Foundation(grant FR/417/6-100/14)the CAS President’s International Fellowship Initiative(PIFI)under Grant No.2017VMA0025
文摘The Wilsonian renormalization group approach to the Lippmann-Schwinger equation with a multitude of cutoff parameters is introduced.A system of integro-differential equations for the cutoff-dependent potential is obtained.As an illustration,a perturbative solution of these equations with two cutoff parameters for a simple case of an S-wave low-energy potential in the form of a Taylor series in momenta is obtained.The relevance of the obtained results for the effective field theory approach to nucleon-nucleon scattering is discussed.
基金Financial support from National Natural Science Foundation of China(Grant No.22201187)the starting grant from Capital Medical University(Grant No.3100-12400123)。
文摘With the hypothesis of simple units integration to create new reactivities,a strategy for the synthesis of polyfunctionalized 5-alkenyl-3-carbonylfurans fromγ-hydroxyl enal and 1,3-dicarbonyl compounds is established,featuring readily available starting materials,high efficiency,good functional groups compatibility,green chemistry with high atom economy and only water release,etc.,to provide a series of polyfunctionalized 5-alkenyl-3-carbonylfurans,which could be applied to the late-stage functionalization of naturally occurring compounds and bioactive molecules,as well as the transformation to pyrroles and polycyclic aromatic hydrocarbon via electrocyclic reaction.Theγ-hydroxyl has played an important role in the unexpected process of ring opening isomerization of 2H-pyran to furanones,as confirmed by detailed mechanistic studies.
基金supported by National Nature Science Foundation of China(No.61203293)Key Scientific and Technological Project of Henan Province(No.122102210131)+3 种基金Program for Science and Technology Innovation Talents in Universities of Henan Province(No.13HASTIT040)Foundation of Henan Educational Committee(No.13A120524)Henan Normal University Doctoral Topics(No.qd14156)Henan Higher School Funding Scheme for Young Teachers(No.2012GGJS-063)
文摘This paper is devoted to identifying the biomarkers of rat liver regeneration via the adaptive logistic regression. By combining the adaptive elastic net penalty with the logistic regression loss, the adaptive logistic regression is proposed to adaptively identify the important genes in groups. Furthermore, by improving the pathwise coordinate descent algorithm, a fast solving algorithm is developed for computing the regularized paths of the adaptive logistic regression. The results from the experiments performed on the microarray data of rat liver regeneration are provided to illustrate the effectiveness of the proposed method and verify the biological rationality of the selected biomarkers.
基金financially supported by the Support Plan for Overseas Students to Return to China for Entrepreneurship and Innovation(cx2020003)the Fundamental Research Funds for the Central Universities(2020CDJ-LHZZ-074)the Natural Science Foundation of Chongqing(cstc2020jcyj-msxm X0629)。
文摘The defects from electron transport layer,perovskite layer and their interface would result in carrier nonradiative recombination losses.Poor buried interfacial contact is detrimental to charge extraction and device stability.Here,we report a bottom-up holistic carrier management strategy induced synergistically by multiple chemical bonds to minimize bulk and interfacial energy losses for high-performance perovskite photovoltaics.4-trifluoromethyl-benzamidine hydrochloride(TBHCl)containing–CF_(3),amidine cation and Cl^(-)is in advance incorporated into SnO_(2)colloid solution to realize bottom-up modification.The synergistic effect of multiple functional groups and multiple-bond-induced chemical interaction are revealed theoretically and experimentally.F and Cl^(-)can passivate oxygen vacancy and/or undercoordinated Sn^(4+)defects by coordinating with Sn^(4+).The F can suppress cation migration and modulate crystallization via hydrogen bond with FA^(+),and can passivate lead defects by coordinating with Pb^(2+).The–NH_(2)–C=NH^(+)_(2)and Cl^(-)can passivate cation and anion vacancy defects through ionic bonds with perovskites,respectively.Through TBHCl modification,the suppression of agglomeration of SnO_(2)nanoparticles,bulk and interfacial defect passivation,and release of tensile strains of perovskite films are demonstrated,which resulted in a PCE enhancement from 21.28%to 23.40%and improved stability.With post-treatment,the efficiency is further improved to 23.63%.
基金The project supported by Major Scientific and Technological Special Project for "Significant New Drug Creation"(2013ZX09508104,2013ZX09402203)by Central Public Scientific Research Institution Fundamental Project(2014CX05)
文摘OBJECTIVE To investigate the cerebralvasorelaxant material basis of Xiaoxuming decoction.METHODS According to the Xiaoxuming decoction herb sources,we retrieved the chemical structure from the literatures and the Chinese Natural Product Database(http://pharmdata.ncmi.cn).By using microvessel tension system,we checked the vasorelaxanteffects of Xiaoxuming decoction anti-cerebral ischemia effective components group(XXMDECG)and the available composition compounds on pre-contracted basilar artery ring.RESULTS963 compoundsin the decoction,including 81Fangfeng,77 Mahuang,130 Shengjiang,31 Guizhi,91 Huangqin,127 Renshen,73 Chuanxiong,44 Shaoyao,39 Xingren,42 Fangji,62 Fuzi and 166 Gancao were collected.The five largest number classes of compounds in the decoction are volatile oil(32%),flavone(32%),alkaloid(13%),saponin(7%),polyphenol and organic acid(5%).XXMDECG at concentration from 1 to 400μg·mL-1can dilate the KCl(60 mmol·L-1)and ET-1(0.01μmol·L-1)pre-contracted rat basilar artery rings in a dose-dependent manner.There are 6 compounds with vasorelaxant ratio more than 50%at the concentration of 10μmol·L-1.CONCLUSION Xiaoxuming decoction contains abundant chemical structure.It has the material basis of multiple ingredients and multiple targets.The XXMDECG are able to dilate the rat basilar artery rings in a dose-dependent manner.The network interactions between varies of chemical compounds in Xiaoxuming decoction and the vasoconstriction associated targets result in the comprehensive regulation mechanisms of vascular function.
基金Project supported by National Natural Science Foundation of China(Grant Nos.11474361,51405405,and 11622430)
文摘Considering the high sensitivity of the nonlinear ultrasonic measurement technique and great advantages of the guided wave testing method, the use of nonlinear ultrasonic guided waves provides a promising means for evaluating and characterizing the hidden and/or inaccessible damage/degradation in solid media. Increasing attention on the development of the testing method based on nonlinear ultrasonic guided waves is largely attributed to the theoretical advances of nonlinear guided waves propagation in solid media. One of the typical acoustic nonlinear responses is the generation of second harmonics that can be used to effectively evaluate damage/degradation in materials/structures. In this paper, the theoretical progress of second-harmonic generation（SHG） of ultrasonic guided wave propagation in solid media is reviewed. The advances and developments of theoretical investigations on the effect of SHG of ultrasonic guided wave propagation in different structures are addressed. Some obscure understandings and the ideas in dispute are also discussed.
基金supported by a grant of the Natural Sciences and Engineering Council of Canadaby a FY2009 Japan Society for the Promotion of Science Invitation Fellowship Program for Research in Japan(Long-term)
文摘In an attempt to clarify issues related to the molecular weight dependence of the phase transition of poly(N-isopropylacrylamide) (PNIPAM) in water,we prepared a library of PNIPAM samples of well-controlled molecular weight (7000 to 45000 g/mol) bearing identical groups on each chain end.The polymers were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization of N-isopropylacrylamide (NIPAM) with a bifunctional chain tranfer agent and further end group modification.The effects of the end group chemical structure,hydroxyethyl (HE),propargyl (Pr),chloroethyl (CE),n-butyl (nBu),n-hexyl (nHe),and isobutylsulfanylthiosulfanyl (IBS) on the phase transition temperature of aqueous PNIPAM solutions were investigated by high-sensitivity differential scanning calorimetry (HS-DSC),yielding the enthalpy ΔH and the endotherm maximum temperature (T M),and turbidimetry,providing the cloud point (T CP) of each solution.The T CP and T M of the PNIPAM sample of lowest molar mass (M n 7,000 g/mol,0.5 g/L) ranged,respectively,from 38.8 to 22.5 °C and 42.2 to 26.0 °C,depending on the structure of the end-group,whereas H showed no strong end-group dependence.The phase transition of all polymers,except,-di(n-butyl-PNIPAM),exhibited a marked dependence on the polymer molar mass.
基金Supported by National Natural Science Foundation of China(No.71462002)the Project for Teaching Reform of Guangxi(GXZZJG2017B084)the Project for Fostering Distinguished Youth Scholars of Guangxi(2020KY50012)。
文摘Variable selection plays an important role in high-dimensional data analysis.But the high-dimensional data often induces the strongly correlated variables problem,which should be properly handled.In this paper,we propose Elastic Net procedure for partially linear models and prove the group effect of its estimate.A simulation study shows that the Elastic Net procedure deals with the strongly correlated variables problem better than the Lasso,ALasso and the Ridge do.Based on the real world data study,we can get that the Elastic Net procedure is particularly useful when the number of predictors pffis much bigger than the sample size n.
文摘It is observed that the regulation sequences at the two ends of every active gene of the heart nuclear DNA fragments may differentially combine with active regulation factors such as some specific binding proteins by using AFM and other experimental technologies. These active genes form different "gene knots", which are separated by "intervals". Using AFM, occasionally, it is also discovered that during the transcription stage, the heart nuclear DNA fragments consist of 3 4 5 "gene knots" and related "intervals", which form various "gene lineages" respectively by some "permutation and combination". Each gene lineage is likely to form nRNA chain like complexes that are 3 times the quantity of gene knots, and each nRNA chain like complex is connected with both ends of corresponding gene lineage. One gene knot of the DNA fragments participates the formation of different gene lineage and corresponding RNA chain like complexes by different combination. By posttranscriptional modification, they can form nmRNA linear chain like complexes that show the speciality of tissues. The beginnings of transcription units have the same number as gene lineages, and all gene lineages in DNA molecules may transcribe efficiently from corresponding beginnings of transcription unit simultaneously. Our work shows the prospective application of AFM in the research of the diversity of gene lineages formation from gene knots in the transcription stage and the efficiency of gene knots transcription.
文摘Using AFM,we observed linear chain-like complexes formed by some specific proteins and the multi-mRNAs during the in vitro expression of some active genes on the DNA fragments. The LDH mRNA in the multi-mRNA complex can in vitro translate LDH. Via AFM, we also discovered that nmRNA prepared from heart muscles, along with some specific proteins can form linear chain-like nmRNA complexes in which LDH mRNA can also translate LDH in vitro. Our work shows the prospective application of AFM in the research of the biological reaction of the active genes on the DNA fragments.
