With the modern development of chemical and mineral admixtures, it is now possible to produce much higher performance concrete than before. Higher performance does not only mean higher strength, but also better durabi...With the modern development of chemical and mineral admixtures, it is now possible to produce much higher performance concrete than before. Higher performance does not only mean higher strength, but also better durability, lower risk of thermal cracking and higher dimensional stability etc. The three most effective admixtures for producing high performance concrete are superplastieizer, pulverized fuel ash and condensed silica fume. This paper outlines the properties of these materials and presents some practical guidelines for their usage.展开更多
This paper studies the effect of different environmental factors, including the axle load weight, environmental temperature, vehicle speed, and the aging level of asphalt, on the fatigue performance of asphalt mixes b...This paper studies the effect of different environmental factors, including the axle load weight, environmental temperature, vehicle speed, and the aging level of asphalt, on the fatigue performance of asphalt mixes based on four-point bending beam fatigue tests. A fractional factorial design method named ＂uniform design＂ was applied in experimental design. The relations of the environmental factors to initial stiffness, fatigue life, phase angle and cumulative dissipated energy were established with the general linear modeling method. It is found that there exists very good correlativity between the environmental factors and the fatigue performance indices of asphalt mixes. The coefficients of total correlation are mainly beyond 0. 95. The results indicate that the consideration of the effect of environmental factors is necessary in the fatigue performance evaluation on real asphalt pavement.展开更多
Aluminium powders were introduced to Al2O3-SiC-C dry ramming mixes in order to improve sintering properties and oxidation resistance according to their service conditions and installation methods. Properties such as b...Aluminium powders were introduced to Al2O3-SiC-C dry ramming mixes in order to improve sintering properties and oxidation resistance according to their service conditions and installation methods. Properties such as bulk density, porosity, modulus of rupture, crushing strength and hot modulus of rupture as a function of aluminium addition were investigated in the present work. The microstructure and thermodynamics for the heat treated specimens were also analyzed. The results show that as aluminium addition increasing, the bulk density of the specimen treated at 220℃ tends to decrease and the apparent porosity increases, the strength of the specimens treated at 1100℃ and 1450℃ increases markedly, the bulk density tends to increase, apparent porosity and linear shrinkage decrease. The HMOR at 1400℃ is enhanced from 1.0 MPa to 3.5 MPa with 3% aluminium. Aluminium is served as sintering agent and anti-oxidant and it will react with CO and CO2 forming Al2O3 , which is helpful to enhance the strength, densify the structure and improve the overall properties.展开更多
Nano silica due to its spherical shape, tiny size and higher density compared to bitumen, may have an inherent potential to improve hot mix asphalt(HMA) self-healing. In this research scanning electron microscopy(SEM)...Nano silica due to its spherical shape, tiny size and higher density compared to bitumen, may have an inherent potential to improve hot mix asphalt(HMA) self-healing. In this research scanning electron microscopy(SEM) images were used to investigate size, morphology and dispersion of nano silica particles. Additionally, HMA self-healing mechanism was also examined by SEM. Furthermore, dynamic indirect tensile test(IDT) was used to evaluate HMA self-healing index. The SEM results indicated that bitumen mortar flowing into micro cracks may be one of the most important mechanisms of HMA self-healing. The experiment results also showed that modification of bitumen by nano silica promotes the ability of the HMA self-healing.展开更多
Mg0-Al2O3-Cr2O3 ramming mixes made of different raw materials have different mineral structure and different physical properties though with the identical particle size distribution, the same amount of binder and chem...Mg0-Al2O3-Cr2O3 ramming mixes made of different raw materials have different mineral structure and different physical properties though with the identical particle size distribution, the same amount of binder and chemical composition . The residual carbon content of the fused magnesia-chrome material made in reducing atmosphere is very high, if this material is used in the MgO-Al203-Cr2O3 ramming mix , it would cause spalling of the furnace lining during drying-out.展开更多
Magnesia-alumina-chrome ramming mixes with same chemical compositions were prepared by using different raw materials such as fused magnesia-chrome synthetic materials and sintered one, wasted bricks and magnesia-alumi...Magnesia-alumina-chrome ramming mixes with same chemical compositions were prepared by using different raw materials such as fused magnesia-chrome synthetic materials and sintered one, wasted bricks and magnesia-alumina spinels. Their physical properties were tested and microstructures were analyzed. The results show that the ramming mixes made of different raw materials bring about different microstructures and properties although the mixes have the same chemical composition, binder content and aggregate size composition.展开更多
Al_(2)O_(3)-SiO_(2) based gunning mixes were prepared with electric porcelain waste,silica fume,bauxite,quartz powder,and calcium aluminate cement(CAC)of different additions as raw materials firing at different temper...Al_(2)O_(3)-SiO_(2) based gunning mixes were prepared with electric porcelain waste,silica fume,bauxite,quartz powder,and calcium aluminate cement(CAC)of different additions as raw materials firing at different temperatures to research the effect of the CAC addition on their phase change and properties.The results show that:from theoretical analysis of the phase diagram,with the CAC addition increasing from 8%to 14%,anorthite increases from 40.0%to 77.7%,by mass.With the rising CAC addition,the permanent linear change on heating of specimens increases;for the specimens dried at 110℃or hot-treated at 1000℃,the bulk density and the mechanical properties increase,and the apparent porosity decreases;and for those hottreated at 1300℃,the bulk density and the mechanical properties firstly increase,and then decrease,while the apparent porosity shows an opposite trend.Taking into account the phases at high temperatures and the properties,the optimal CAC addition of Al_(2)O_(3)-SiO_(2) based gunning mixes is 12%.展开更多
Current pavement design methods do not allow for the reduction of early deformation of the surface layers of bituminous pavements in the city of Ouagadougou. Weather conditions combined with traffic, particularly duri...Current pavement design methods do not allow for the reduction of early deformation of the surface layers of bituminous pavements in the city of Ouagadougou. Weather conditions combined with traffic, particularly during heat waves, are factors. The temperature at the surface of the bituminous pavement can reach 62˚C but the complex modulus associated with this temperature is not taken into account in the design, hence the interest in proposing laws of dependence of the complex moduli is taken into account in the maximum temperatures of the pavement surface. The objective of this paper is to propose an experimental method to determine the temperature dependence of the complex moduli of asphalt mixes for temperatures between 40˚C and 70˚C. This experimental method consists of performing axial compression tests on cylindrical asphalt specimens. It was applied to three different formulas of bituminous mixes, intended for the wearing course, obtained from mixes of crushed granites, granular classes 6/10, 4/6 and 0/4, pure bitumens of grade 50/70, 35/50 and modified bitumen of grade 10/65. The comparative study of the experimental results obtained with the results of a semi-empirical methodology revealed a root mean square deviation from the mean of between 6.58% and 14.8% of the norms of the complex moduli (modulus of rigidity) of the asphalt mixes for a fixed frequency of solicitations of 10 Hz. The consistency of these results with data from the literature led to the initial conclusion that asphalt mixes formulated with 35/50 and 10/65 bitumen would have better compressive strength than those formulated with 50/70 bitumen, for exposure temperatures between 40˚C and 70˚C. This experimental approach could be an alternative to the complex modulus test for determining the modulus of rigidity for design purposes under real pavement exposure conditions in the city of Ouagadougou during heat waves.展开更多
Evaluating the functional boundary of different types of innovation policy instruments and their mixes on innovation performance of enterprises is an important but unresolved key issue.This paper,based on the systemat...Evaluating the functional boundary of different types of innovation policy instruments and their mixes on innovation performance of enterprises is an important but unresolved key issue.This paper,based on the systematically carding the quantization of 155 innovation policies issued by Shenzhen governmental departments from 2011 to 2019,analyzed the characteristics from different types of innovation instruments and their mixes.The results show that Shenzhen governmental has constantly enriched innovation policy instruments for encouraging enterprise innovation,but there are structural unbalances in the issued innovation policy manifested as follows:firstly supply-side policy and environmental-side policy were promulgated more than demand-side policy;secondly the specific instruments employed by Shenzhen governmental were also uneven in different type of innovation policy,like supply-side policy focused on the instruments of government procurement and R&D outsourcing,demand-side policy employed human resource training,innovation infrastructure and fiscal support most,and environmental-side policy main used target planning,intellectual property protection and financial support.This study expands and understanding empirical implementation of different reginal innovation policy instruments,and has implication for Shenzhen governmental in improving the applicability ability of policies in the enterprises innovation.展开更多
Presently,many asphalts and modified asphalts fail to satisfy long-term serviceability and durability criteria.Researchers are utilizing several asphalt modifiers to enhance the overall performance of flexible pavemen...Presently,many asphalts and modified asphalts fail to satisfy long-term serviceability and durability criteria.Researchers are utilizing several asphalt modifiers to enhance the overall performance of flexible pavements.This study consolidated findings from multiple research efforts on using nanomaterials for modifying SBS modified asphalt(SBS MA)and conducted a comprehensive literature review.Initially,it discussed the importance of SBS MA within asphalt modification systems and identified the key nanomaterials utilized in SBS modified asphalt.After this,it reviewed their preparation methods,dispersion and characterization techniques,and their impact on the key performance parameters of SBS MA binder and its mixture such as viscosity,rutting resistance,fatigue resistance,ageing and moisture damage etc.Additionally,it highlighted the advantages of nanomaterials over other modifiers.This study also addressed the challenges and limitations of incorporating nanomaterials in SBS MA.The findings indicated that when properly integrated,nanomaterials could significantly improve the performance of SBS MA,making them a promising addition to future road construction and maintenance projects.However,using nanomaterials for SBS MA modifications and mixtures has been challenged by limited practical applications,insufficient life cycle cost analyses,a lack of standardized guidelines,cost-effective nanomaterials and insufficient mixing procedures.Those areas require additional research to realise the potential application of nanomaterials in SBS modified asphalt modifications full.展开更多
Properties of aggregates are majorly influenced by parameters of source rocks viz.,formation process,chemical composition,impurities,volume of pores,and grain size.The study presents a review of aggregate treatment me...Properties of aggregates are majorly influenced by parameters of source rocks viz.,formation process,chemical composition,impurities,volume of pores,and grain size.The study presents a review of aggregate treatment methods and its efficacy to enhance the quality of aggregate.Various aspects of aggregate treatment methods like processing temperature,the dosage of additives,adaptability in the field is studied for three treatment methods viz.,polymer coating,cementitious coating,and chemical treatments.The paper also presents an insight to understand the effect of different treatment methods on mix properties and performance parameters of asphalt mixes.The review revealed that the shape properties of aggregates can be enhanced by the incorporating suitable crushing process(two-stage or three-stage).Whereas,physical and durability properties of aggregates can be improved by various treatment methods like polymer coating,Zycosoil treatment.It was further inferred from the review that treatment methods can have moderate effects on the mechanical properties of aggregates,since,it is mostly dependent on properties of source rocks.展开更多
The earthworm-based vermiremediation facilitated with benign chemicals such as nano zero-valent iron(nZVI)is a promising approach for the remediation of a variety of soil contaminants including cyanotoxins.As themost ...The earthworm-based vermiremediation facilitated with benign chemicals such as nano zero-valent iron(nZVI)is a promising approach for the remediation of a variety of soil contaminants including cyanotoxins.As themost toxic cyanotoxin,microcystin-LR(MC-LR)enter soil via runoff,irrigated surface water and sewage,and the application of cyanobacterial biofertilizers as part of the sustainable agricultural practice.Earthworms in such remediation systems must sustain the potential risk from both nZVI and MC-LR.In the present study,earthworms(Eisenia fetida)were exposed up to 14 days to MC-LR and nZVI(individually and inmixture),and the toxicity was investigated at both the organismal andmetabolic levels,including growth,tissue damage,oxidative stress,metabolic response and gut microbiota.Results showed that co-exposure of MC-LR and nZVI is less potent to earthworms than that of separate exposure.Histological observations in the co-exposure group revealed only minor epidermal brokenness,and KEGG enrichment analysis showed that co-exposure induced earthworms to regulate glutathione biosynthesis for detoxification and reduced adverse effects from MC-LR.The combined use of nZVI promoted the growth and reproduction of soil and earthworm gut bacteria(e.g.,Sphingobacterium and Acinetobacter)responsible for the degradation of MC-LR,whichmight explain the observed antagonism between nZVI and MC-LR in earthworm microcosm.Our study suggests the beneficial use of nZVI to detoxify pollutants in earthworm-based vermiremediation systems where freshwater containing cyanobacterial blooms is frequently used to irrigate soil and supply water for the growth and metabolism of earthworms.展开更多
This paper deals with Raviart-Thomas element (Q(2,1) x Q(1,2) - Q(1) element). Apart from its global superconvergence property of fourth order, we prove that a postprocessed extrapolation can globally increased the ac...This paper deals with Raviart-Thomas element (Q(2,1) x Q(1,2) - Q(1) element). Apart from its global superconvergence property of fourth order, we prove that a postprocessed extrapolation can globally increased the accuracy by fifth order.展开更多
Brazil’s deforestation monitoring integrates accuracy and current monitoring for land use and land cover applications.Regular monitoring of deforestation and non-deforestation requires Sentinel-2 multispectral satell...Brazil’s deforestation monitoring integrates accuracy and current monitoring for land use and land cover applications.Regular monitoring of deforestation and non-deforestation requires Sentinel-2 multispectral satellite images of several bands at various frequencies,the mix of high-and low-resolution images that make object classification difficult because of the mixed pixel problem.Accuracy is impacted by the mixed pixel problem,which occurs when pixels belong to different classes and makes detection challenging.To identify mixed pixels,Band Math is used to merge numerous bands to generate a new band NDVI.Thresholding is used to analyze the edges of deforested and non-deforested areas.Segmentation is then used to analyze the pixels which helps to identify the number of mixed pixels to compute the deforested and non-deforested areas.Segmented image pixels are used to categorize the deforestation of the Brazilian Amazon Forest between 2019 and 2023.Verify how many pixels are mixed to improve accuracy and identify mixed pixel issues;compare the mixed and pure pixels of fuzzy clustering with the subtracted morphological image pixels.With the help of segmentation and clustering researchers effectively validate mixed pixels in a specific area.The proposed methodology is easy to analyze and helpful for an appropriate calculation of deforested and non-deforested areas.展开更多
Phantom limb pain(PLP)is not only a physical pain experience but also poses a significant challenge to mental health and quality of life.Currently,the mechanism of PLP treatment is still unclear,and there are many met...Phantom limb pain(PLP)is not only a physical pain experience but also poses a significant challenge to mental health and quality of life.Currently,the mechanism of PLP treatment is still unclear,and there are many methods with varying effects.This article starts with the application research of extended reality technology in PLP treatment,through describing the application of its branch technologies(virtual reality,augmented reality,and mixed reality technology),to lay the foundation for subsequent research,in the hope of finding advanced and effective treatment methods,and providing a basis for future product transformation.展开更多
The present study introduces a screw-pressing charging method to tackle deficiencies in automation and charge uniformity during the melt-casting of polymer-based energetic materials.To ensure the safety of the experim...The present study introduces a screw-pressing charging method to tackle deficiencies in automation and charge uniformity during the melt-casting of polymer-based energetic materials.To ensure the safety of the experiments,this study used inert materials with similar physical properties to partially substitute for the actual energetic components in the preparation of simulant materials.By thoroughly analyzing slurry physical properties,a simulation framework and an extensive performance evaluation method were developed.Such tools guide the design of the structure and configuration of process parameters.Results demonstrate that employing the Pin element significantly enhances radial mixing within the screw,minimizes temperature variations in the slurry,and improves both efficiency and safety in the mixing process.Further,adjustments such as widening the cone angle of the barrel,modifying the solid content of the slurry,and varying the speed of the screw can optimize the mechanical and thermal coupling in the flow field.These adjustments promote higher-quality slurry and create a safer production environment for the extrusion process.展开更多
BACKGROUND A total of 100 patients diagnosed with mixed hemorrhoids from October 2022 to September 2023 in our hospital were randomly divided into groups by dice rolling and compared with the efficacy of different tre...BACKGROUND A total of 100 patients diagnosed with mixed hemorrhoids from October 2022 to September 2023 in our hospital were randomly divided into groups by dice rolling and compared with the efficacy of different treatment options.AIM To analyze the clinical effect and prognosis of mixed hemorrhoids treated with polidocanol injection combined with automatic elastic thread ligation operation(RPH).METHODS A total of 100 patients with mixed hemorrhoids who visited our hospital from October 2022 to September 2023 were selected and randomly divided into the control group(n=50)and the treatment group(n=50)by rolling the dice.The procedure for prolapse and hemorrhoids(PPH)was adopted in the control group,while polidocanol foam injection+RPH was adopted in the treatment group.The therapeutic effects,operation time,wound healing time,hospital stay,pain situation(24 hours post-operative pain score,first defecation pain score),quality of life(QOL),incidence of complications(post-operative hemorrhage,edema,infection),incidence of anal stenosis 3 months post-operatively and recurrence rate 1 year post-operatively of the two groups were compared.RESULTS Compared with the control group,the total effective rate of treatment group was higher,and the difference was significant(P<0.05).The operation time/wound healing time/hospital stay in the treatment group were shorter than those in the control group(P<0.05).The pain scores at 24 hours after operation/first defecation pain score of the treatment group was significantly lower than those in the control group(P<0.05).After surgery,the QOL scores of the two groups decreased,with the treatment group having higher scores than that of the control group(P<0.05).Compared with the control group,the incidence of postoperative complications in the treatment group was lower,and the difference was significant(P<0.05);However,there was no significant difference in the incidence of postoperative bleeding between the two groups(P>0.05);There was no significant difference in the incidence of anal stenosis 3 months after operation and the recurrence rate 1 year after operation between the two groups(P>0.05).CONCLUSION For patients with mixed hemorrhoids,the therapeutic effect achieved by using polidocanol injection combined with RPH was better.The wounds of the patients healed faster,the postoperative pain was milder,QOL improved,and the incidence of complications was lower,and the short-term and long-term prognosis was good.展开更多
Direct seawater splitting has emerged as a popular and promising research direction for synthesising clean,green,non-polluting,and sustainable hydrogen energy without depending on high-purity water in the face of the ...Direct seawater splitting has emerged as a popular and promising research direction for synthesising clean,green,non-polluting,and sustainable hydrogen energy without depending on high-purity water in the face of the world’s shortage of fossil energy.However,efficient seawater splitting is hindered by slow kinetics caused by the ultra-low conductivity and the presence of bacteria,microorganisms,and stray ions in seawater.Additionally,producing hydrogen on an industrial scale is challenging due to the high production cost.The present review addresses these challenges from the catalyst point of view,namely,that designing catalysts with high catalytic activity and stability can directly affect the rate and effect of seawater splitting.From the ion transfer perspective,designing membranes can block harmful ions,improving the stability of seawater splitting.From the energy point of view,mixed seawater systems and self-powered systems also provide new and low-energy research systems for seawater splitting.Finally,ideas and directions for further research on direct seawater splitting in the future are pointed out,with the aim of achieving low-cost and high-efficiency hydrogen production.展开更多
文摘With the modern development of chemical and mineral admixtures, it is now possible to produce much higher performance concrete than before. Higher performance does not only mean higher strength, but also better durability, lower risk of thermal cracking and higher dimensional stability etc. The three most effective admixtures for producing high performance concrete are superplastieizer, pulverized fuel ash and condensed silica fume. This paper outlines the properties of these materials and presents some practical guidelines for their usage.
文摘This paper studies the effect of different environmental factors, including the axle load weight, environmental temperature, vehicle speed, and the aging level of asphalt, on the fatigue performance of asphalt mixes based on four-point bending beam fatigue tests. A fractional factorial design method named ＂uniform design＂ was applied in experimental design. The relations of the environmental factors to initial stiffness, fatigue life, phase angle and cumulative dissipated energy were established with the general linear modeling method. It is found that there exists very good correlativity between the environmental factors and the fatigue performance indices of asphalt mixes. The coefficients of total correlation are mainly beyond 0. 95. The results indicate that the consideration of the effect of environmental factors is necessary in the fatigue performance evaluation on real asphalt pavement.
文摘Aluminium powders were introduced to Al2O3-SiC-C dry ramming mixes in order to improve sintering properties and oxidation resistance according to their service conditions and installation methods. Properties such as bulk density, porosity, modulus of rupture, crushing strength and hot modulus of rupture as a function of aluminium addition were investigated in the present work. The microstructure and thermodynamics for the heat treated specimens were also analyzed. The results show that as aluminium addition increasing, the bulk density of the specimen treated at 220℃ tends to decrease and the apparent porosity increases, the strength of the specimens treated at 1100℃ and 1450℃ increases markedly, the bulk density tends to increase, apparent porosity and linear shrinkage decrease. The HMOR at 1400℃ is enhanced from 1.0 MPa to 3.5 MPa with 3% aluminium. Aluminium is served as sintering agent and anti-oxidant and it will react with CO and CO2 forming Al2O3 , which is helpful to enhance the strength, densify the structure and improve the overall properties.
文摘Nano silica due to its spherical shape, tiny size and higher density compared to bitumen, may have an inherent potential to improve hot mix asphalt(HMA) self-healing. In this research scanning electron microscopy(SEM) images were used to investigate size, morphology and dispersion of nano silica particles. Additionally, HMA self-healing mechanism was also examined by SEM. Furthermore, dynamic indirect tensile test(IDT) was used to evaluate HMA self-healing index. The SEM results indicated that bitumen mortar flowing into micro cracks may be one of the most important mechanisms of HMA self-healing. The experiment results also showed that modification of bitumen by nano silica promotes the ability of the HMA self-healing.
文摘Mg0-Al2O3-Cr2O3 ramming mixes made of different raw materials have different mineral structure and different physical properties though with the identical particle size distribution, the same amount of binder and chemical composition . The residual carbon content of the fused magnesia-chrome material made in reducing atmosphere is very high, if this material is used in the MgO-Al203-Cr2O3 ramming mix , it would cause spalling of the furnace lining during drying-out.
文摘Magnesia-alumina-chrome ramming mixes with same chemical compositions were prepared by using different raw materials such as fused magnesia-chrome synthetic materials and sintered one, wasted bricks and magnesia-alumina spinels. Their physical properties were tested and microstructures were analyzed. The results show that the ramming mixes made of different raw materials bring about different microstructures and properties although the mixes have the same chemical composition, binder content and aggregate size composition.
文摘Al_(2)O_(3)-SiO_(2) based gunning mixes were prepared with electric porcelain waste,silica fume,bauxite,quartz powder,and calcium aluminate cement(CAC)of different additions as raw materials firing at different temperatures to research the effect of the CAC addition on their phase change and properties.The results show that:from theoretical analysis of the phase diagram,with the CAC addition increasing from 8%to 14%,anorthite increases from 40.0%to 77.7%,by mass.With the rising CAC addition,the permanent linear change on heating of specimens increases;for the specimens dried at 110℃or hot-treated at 1000℃,the bulk density and the mechanical properties increase,and the apparent porosity decreases;and for those hottreated at 1300℃,the bulk density and the mechanical properties firstly increase,and then decrease,while the apparent porosity shows an opposite trend.Taking into account the phases at high temperatures and the properties,the optimal CAC addition of Al_(2)O_(3)-SiO_(2) based gunning mixes is 12%.
文摘Current pavement design methods do not allow for the reduction of early deformation of the surface layers of bituminous pavements in the city of Ouagadougou. Weather conditions combined with traffic, particularly during heat waves, are factors. The temperature at the surface of the bituminous pavement can reach 62˚C but the complex modulus associated with this temperature is not taken into account in the design, hence the interest in proposing laws of dependence of the complex moduli is taken into account in the maximum temperatures of the pavement surface. The objective of this paper is to propose an experimental method to determine the temperature dependence of the complex moduli of asphalt mixes for temperatures between 40˚C and 70˚C. This experimental method consists of performing axial compression tests on cylindrical asphalt specimens. It was applied to three different formulas of bituminous mixes, intended for the wearing course, obtained from mixes of crushed granites, granular classes 6/10, 4/6 and 0/4, pure bitumens of grade 50/70, 35/50 and modified bitumen of grade 10/65. The comparative study of the experimental results obtained with the results of a semi-empirical methodology revealed a root mean square deviation from the mean of between 6.58% and 14.8% of the norms of the complex moduli (modulus of rigidity) of the asphalt mixes for a fixed frequency of solicitations of 10 Hz. The consistency of these results with data from the literature led to the initial conclusion that asphalt mixes formulated with 35/50 and 10/65 bitumen would have better compressive strength than those formulated with 50/70 bitumen, for exposure temperatures between 40˚C and 70˚C. This experimental approach could be an alternative to the complex modulus test for determining the modulus of rigidity for design purposes under real pavement exposure conditions in the city of Ouagadougou during heat waves.
基金funded by National Nature Science Foundation of China[grant number 72172041]Social Project by Ministry of Education[grant number 20YJC630022]+1 种基金Shenzhen Philosophy and social science program in 2021[grant number SZ2021D016]University project from Shenzhen Institute of Information Technology in 20212[grant number SZIIT2021SK007].
文摘Evaluating the functional boundary of different types of innovation policy instruments and their mixes on innovation performance of enterprises is an important but unresolved key issue.This paper,based on the systematically carding the quantization of 155 innovation policies issued by Shenzhen governmental departments from 2011 to 2019,analyzed the characteristics from different types of innovation instruments and their mixes.The results show that Shenzhen governmental has constantly enriched innovation policy instruments for encouraging enterprise innovation,but there are structural unbalances in the issued innovation policy manifested as follows:firstly supply-side policy and environmental-side policy were promulgated more than demand-side policy;secondly the specific instruments employed by Shenzhen governmental were also uneven in different type of innovation policy,like supply-side policy focused on the instruments of government procurement and R&D outsourcing,demand-side policy employed human resource training,innovation infrastructure and fiscal support most,and environmental-side policy main used target planning,intellectual property protection and financial support.This study expands and understanding empirical implementation of different reginal innovation policy instruments,and has implication for Shenzhen governmental in improving the applicability ability of policies in the enterprises innovation.
基金supported by the Key R&D Project in Shaanxi Province(No.2024GX-YBXM-371)Shaanxi Qinchuangyuan“Scientists+Engineers”Team Construction Project(2025QCY-KXJ-141).
文摘Presently,many asphalts and modified asphalts fail to satisfy long-term serviceability and durability criteria.Researchers are utilizing several asphalt modifiers to enhance the overall performance of flexible pavements.This study consolidated findings from multiple research efforts on using nanomaterials for modifying SBS modified asphalt(SBS MA)and conducted a comprehensive literature review.Initially,it discussed the importance of SBS MA within asphalt modification systems and identified the key nanomaterials utilized in SBS modified asphalt.After this,it reviewed their preparation methods,dispersion and characterization techniques,and their impact on the key performance parameters of SBS MA binder and its mixture such as viscosity,rutting resistance,fatigue resistance,ageing and moisture damage etc.Additionally,it highlighted the advantages of nanomaterials over other modifiers.This study also addressed the challenges and limitations of incorporating nanomaterials in SBS MA.The findings indicated that when properly integrated,nanomaterials could significantly improve the performance of SBS MA,making them a promising addition to future road construction and maintenance projects.However,using nanomaterials for SBS MA modifications and mixtures has been challenged by limited practical applications,insufficient life cycle cost analyses,a lack of standardized guidelines,cost-effective nanomaterials and insufficient mixing procedures.Those areas require additional research to realise the potential application of nanomaterials in SBS modified asphalt modifications full.
基金National Highways Authority of India(NHAI)for providing financial support to carry out this research。
文摘Properties of aggregates are majorly influenced by parameters of source rocks viz.,formation process,chemical composition,impurities,volume of pores,and grain size.The study presents a review of aggregate treatment methods and its efficacy to enhance the quality of aggregate.Various aspects of aggregate treatment methods like processing temperature,the dosage of additives,adaptability in the field is studied for three treatment methods viz.,polymer coating,cementitious coating,and chemical treatments.The paper also presents an insight to understand the effect of different treatment methods on mix properties and performance parameters of asphalt mixes.The review revealed that the shape properties of aggregates can be enhanced by the incorporating suitable crushing process(two-stage or three-stage).Whereas,physical and durability properties of aggregates can be improved by various treatment methods like polymer coating,Zycosoil treatment.It was further inferred from the review that treatment methods can have moderate effects on the mechanical properties of aggregates,since,it is mostly dependent on properties of source rocks.
基金supported by the National Natural Science Foundation of China(No.21777139)the National Key Research and Development Program of China(No.2017YFA0207003).
文摘The earthworm-based vermiremediation facilitated with benign chemicals such as nano zero-valent iron(nZVI)is a promising approach for the remediation of a variety of soil contaminants including cyanotoxins.As themost toxic cyanotoxin,microcystin-LR(MC-LR)enter soil via runoff,irrigated surface water and sewage,and the application of cyanobacterial biofertilizers as part of the sustainable agricultural practice.Earthworms in such remediation systems must sustain the potential risk from both nZVI and MC-LR.In the present study,earthworms(Eisenia fetida)were exposed up to 14 days to MC-LR and nZVI(individually and inmixture),and the toxicity was investigated at both the organismal andmetabolic levels,including growth,tissue damage,oxidative stress,metabolic response and gut microbiota.Results showed that co-exposure of MC-LR and nZVI is less potent to earthworms than that of separate exposure.Histological observations in the co-exposure group revealed only minor epidermal brokenness,and KEGG enrichment analysis showed that co-exposure induced earthworms to regulate glutathione biosynthesis for detoxification and reduced adverse effects from MC-LR.The combined use of nZVI promoted the growth and reproduction of soil and earthworm gut bacteria(e.g.,Sphingobacterium and Acinetobacter)responsible for the degradation of MC-LR,whichmight explain the observed antagonism between nZVI and MC-LR in earthworm microcosm.Our study suggests the beneficial use of nZVI to detoxify pollutants in earthworm-based vermiremediation systems where freshwater containing cyanobacterial blooms is frequently used to irrigate soil and supply water for the growth and metabolism of earthworms.
文摘This paper deals with Raviart-Thomas element (Q(2,1) x Q(1,2) - Q(1) element). Apart from its global superconvergence property of fourth order, we prove that a postprocessed extrapolation can globally increased the accuracy by fifth order.
文摘Brazil’s deforestation monitoring integrates accuracy and current monitoring for land use and land cover applications.Regular monitoring of deforestation and non-deforestation requires Sentinel-2 multispectral satellite images of several bands at various frequencies,the mix of high-and low-resolution images that make object classification difficult because of the mixed pixel problem.Accuracy is impacted by the mixed pixel problem,which occurs when pixels belong to different classes and makes detection challenging.To identify mixed pixels,Band Math is used to merge numerous bands to generate a new band NDVI.Thresholding is used to analyze the edges of deforested and non-deforested areas.Segmentation is then used to analyze the pixels which helps to identify the number of mixed pixels to compute the deforested and non-deforested areas.Segmented image pixels are used to categorize the deforestation of the Brazilian Amazon Forest between 2019 and 2023.Verify how many pixels are mixed to improve accuracy and identify mixed pixel issues;compare the mixed and pure pixels of fuzzy clustering with the subtracted morphological image pixels.With the help of segmentation and clustering researchers effectively validate mixed pixels in a specific area.The proposed methodology is easy to analyze and helpful for an appropriate calculation of deforested and non-deforested areas.
文摘Phantom limb pain(PLP)is not only a physical pain experience but also poses a significant challenge to mental health and quality of life.Currently,the mechanism of PLP treatment is still unclear,and there are many methods with varying effects.This article starts with the application research of extended reality technology in PLP treatment,through describing the application of its branch technologies(virtual reality,augmented reality,and mixed reality technology),to lay the foundation for subsequent research,in the hope of finding advanced and effective treatment methods,and providing a basis for future product transformation.
基金financially supported by the Fundamental Research Funds for the Central Universities(Grant No.30923011018)。
文摘The present study introduces a screw-pressing charging method to tackle deficiencies in automation and charge uniformity during the melt-casting of polymer-based energetic materials.To ensure the safety of the experiments,this study used inert materials with similar physical properties to partially substitute for the actual energetic components in the preparation of simulant materials.By thoroughly analyzing slurry physical properties,a simulation framework and an extensive performance evaluation method were developed.Such tools guide the design of the structure and configuration of process parameters.Results demonstrate that employing the Pin element significantly enhances radial mixing within the screw,minimizes temperature variations in the slurry,and improves both efficiency and safety in the mixing process.Further,adjustments such as widening the cone angle of the barrel,modifying the solid content of the slurry,and varying the speed of the screw can optimize the mechanical and thermal coupling in the flow field.These adjustments promote higher-quality slurry and create a safer production environment for the extrusion process.
文摘BACKGROUND A total of 100 patients diagnosed with mixed hemorrhoids from October 2022 to September 2023 in our hospital were randomly divided into groups by dice rolling and compared with the efficacy of different treatment options.AIM To analyze the clinical effect and prognosis of mixed hemorrhoids treated with polidocanol injection combined with automatic elastic thread ligation operation(RPH).METHODS A total of 100 patients with mixed hemorrhoids who visited our hospital from October 2022 to September 2023 were selected and randomly divided into the control group(n=50)and the treatment group(n=50)by rolling the dice.The procedure for prolapse and hemorrhoids(PPH)was adopted in the control group,while polidocanol foam injection+RPH was adopted in the treatment group.The therapeutic effects,operation time,wound healing time,hospital stay,pain situation(24 hours post-operative pain score,first defecation pain score),quality of life(QOL),incidence of complications(post-operative hemorrhage,edema,infection),incidence of anal stenosis 3 months post-operatively and recurrence rate 1 year post-operatively of the two groups were compared.RESULTS Compared with the control group,the total effective rate of treatment group was higher,and the difference was significant(P<0.05).The operation time/wound healing time/hospital stay in the treatment group were shorter than those in the control group(P<0.05).The pain scores at 24 hours after operation/first defecation pain score of the treatment group was significantly lower than those in the control group(P<0.05).After surgery,the QOL scores of the two groups decreased,with the treatment group having higher scores than that of the control group(P<0.05).Compared with the control group,the incidence of postoperative complications in the treatment group was lower,and the difference was significant(P<0.05);However,there was no significant difference in the incidence of postoperative bleeding between the two groups(P>0.05);There was no significant difference in the incidence of anal stenosis 3 months after operation and the recurrence rate 1 year after operation between the two groups(P>0.05).CONCLUSION For patients with mixed hemorrhoids,the therapeutic effect achieved by using polidocanol injection combined with RPH was better.The wounds of the patients healed faster,the postoperative pain was milder,QOL improved,and the incidence of complications was lower,and the short-term and long-term prognosis was good.
基金support by National Key Research and Development Program of China(2022YFB3803502)National Natural Science Foundation of China(52103076)+5 种基金Science and Technology Commission of Shanghai Municipality(23ZR1400300)special fund of Beijing Key Laboratory of Indoor Air Quality Evaluat ion and Control(NO.BZ0344KF21-02)State Key Laboratory of Electrical Insulation and Power Equipment(EIPE22203)JLF is a member of LSRE-LCM–Laboratory of Separation and Reaction Engineering-Laboratory of Catalysis and Materials,supported by national funds through FCT/MCTES(PIDDAC):LSRE-LCM,UIDB/50020/2020(DOI:10.54499/UIDB/50020/2020)UIDP/50020/2020(DOI:10.54499/UIDP/50020/2020)ALiCE,LA/P/0045/2020(DOI:10.54499/LA/P/0045/2020).
文摘Direct seawater splitting has emerged as a popular and promising research direction for synthesising clean,green,non-polluting,and sustainable hydrogen energy without depending on high-purity water in the face of the world’s shortage of fossil energy.However,efficient seawater splitting is hindered by slow kinetics caused by the ultra-low conductivity and the presence of bacteria,microorganisms,and stray ions in seawater.Additionally,producing hydrogen on an industrial scale is challenging due to the high production cost.The present review addresses these challenges from the catalyst point of view,namely,that designing catalysts with high catalytic activity and stability can directly affect the rate and effect of seawater splitting.From the ion transfer perspective,designing membranes can block harmful ions,improving the stability of seawater splitting.From the energy point of view,mixed seawater systems and self-powered systems also provide new and low-energy research systems for seawater splitting.Finally,ideas and directions for further research on direct seawater splitting in the future are pointed out,with the aim of achieving low-cost and high-efficiency hydrogen production.
