This study aims to determine the variation and controlling factors of shale gas adsorption capacity in reservoirs in the Upper Ordovician Wufeng Formation and the Lower Silurian Longmaxi Formation(also referred to as ...This study aims to determine the variation and controlling factors of shale gas adsorption capacity in reservoirs in the Upper Ordovician Wufeng Formation and the Lower Silurian Longmaxi Formation(also referred to as the WF-LMX formations),South China.Based on data obtained using scanning helium ion microscopy(HIM)and nitrogen(N_(2))and methane(CH_(4))adsorption experiments,this study analyzed the organic pore heterogeneity of shales in the WF-LMX formations in well A and its effect on shale gas adsorption.Using the Frenkel-Halsey-Hill(FHH)model,data from N_(2) adsorption experiments were converted into fractal dimensions,which can reflect the complexity and heterogeneity of organic pores while also serving as a novel indicator for quantitatively assessing the pore structure complexity.The results indicate that shales in the WF-LMX formations in well A can be divided into two sections:(Ⅰ)the Wufeng Formation and the lower Longmaxi Formation(depths:ca.2871.0-2898.6 m),and(Ⅱ)the upper Longmaxi Formation(depths:<2871.0 m).Organic pores in Section Ⅰ typically exhibit complex internal structures,coarse surfaces,and interconnectivity,whereas those in Section Ⅱ are simple,smooth,and isolated.Moreover,the former possesses larger specific surface areas(SSAs)than the latter.A fractal analysis reveals that organic pores in the shale sequence can be classified into micropores(<2 nm),mesopores(2-10 nm),and macropores(>10 nm).The calculated fractal dimensions show greater heterogeneity of organic pores,especially macropores,in Section Ⅰ compared to Section Ⅱ.The results also reveal that organic macropores are the primary pores controlling the SSAs of organic pores in shale reservoirs in the WF-LMX formations.Organic pores in Section Ⅰ manifest a superior shale gas adsorption capacity compared to Section Ⅱ.The heterogeneity of organic pores might affect the adsorption capacity of shales in the formations.Generally,organic macropores in Section Ⅰ of the shale sequence exhibit more complex structures and larger SSAs,leading to a stronger absorption capacity of shale reservoirs in Section Ⅰ compared to Section Ⅱ.展开更多
[Objective] This study aimed to analyze the differences in absorption capacity of different flue-cured tobacco cultivars for chromium （Cr）, arsenic （As）, cadmium （Cd）, lead （Pb）, mercury （Hg） and copper （Cu...[Objective] This study aimed to analyze the differences in absorption capacity of different flue-cured tobacco cultivars for chromium （Cr）, arsenic （As）, cadmium （Cd）, lead （Pb）, mercury （Hg） and copper （Cu）. [Method] With 4 flue-cured tobacco cultivars as the experimental materials, their absorption capacity for 6 kinds of heavy metals was compared by pot experiment. [Result] There were great differences in absorption capacity of different flue-cured tobacco cultivars for the six kinds of heavy metals. According to the absorption capacity of different flue-cured tobacco cultivars for the heavy metals, the six heavy metals could be classified into three categories. The first category included only Cd with average enrichment coefficient of 8.564; the second category included Hg with average enrichment coefficient of 0.753; and the third category included Cr, As, Pb and Cu with average enrichment coefficients below or equivalent to 0.114. [Conclusion] The absorption capacity of different flue-cured tobacco cultivars for heavy metals was grasped by this study, thereby providing reference data for screening of high-yielding and high-quality flue-cured tobacco cultivars.展开更多
a firm＇ s absorption capacity is a key factor to affect the knowledge transfer in ERP implementation, which influences the implementation of ERP By involving the subject - the ERP implementation of enterprise, ERP im...a firm＇ s absorption capacity is a key factor to affect the knowledge transfer in ERP implementation, which influences the implementation of ERP By involving the subject - the ERP implementation of enterprise, ERP implementation is mainly the knowledge absorption of enterprise from the implementation service provider. It analyzes the factors that influence the absorption capacity in the implementation of Deluding the characteristics of the internal and external and knowledge itself, which promote the successful implementation of ERP.展开更多
This study investigated the microstructure and hydrogen absorption properties of a rare-earth high-entropy alloy(HEA),YGdTbDyHo.Results indicated that the YGdTbDyHo alloy had a microstructure of equiaxed grains,with t...This study investigated the microstructure and hydrogen absorption properties of a rare-earth high-entropy alloy(HEA),YGdTbDyHo.Results indicated that the YGdTbDyHo alloy had a microstructure of equiaxed grains,with the alloy elements distributed homogeneously.Upon hydrogen absorption,the phase structure of the HEA changed from a solid solution with an hexagonal-close-packed(HCP)structure to a high-entropy hydride with an faced-centered-cubic(FCC)structure without any secondary phase precipitated.The alloy demonstrated a maximum hydrogen storage capacity of 2.33 H/M(hydrogen atom/metal atom)at 723 K,with an enthalpy change(ΔH)of-141.09 kJ·mol^(-1)and an entropy change(ΔS)of-119.14 J·mol^(-1)·K^(-1).The kinetic mechanism of hydrogen absorption was hydride nucleation and growth,with an apparent activation energy(E_(a))of 20.90 kJ·mol^(-1).Without any activation,the YGdTbDyHo alloy could absorb hydrogen quickly(180 s at 923 K)with nearly no incubation period observed.The reason for the obtained value of 2.33 H/M was that the hydrogen atoms occupied both tetrahedral and octahedral interstices.These results demonstrate the potential application of HEAs as a high-capacity hydrogen storage material with a large H/M ratio,which can be used in the deuterium storage field.展开更多
Carbon dioxide(CO_(2))is the predominant greenhouse gas in the Earth’s atmosphere and plays a crucial role in global warming.Given the inherent limitations of monoethanolamine absorbents in current commercial large-s...Carbon dioxide(CO_(2))is the predominant greenhouse gas in the Earth’s atmosphere and plays a crucial role in global warming.Given the inherent limitations of monoethanolamine absorbents in current commercial large-scale CO_(2)capture applications,amino acid ionic liquids(AAILs)have garnered extensive interest in this field due to their adjustable structure,low volatility,high thermal stability,and significant absorption capacity.However,the number of comprehensive reviews recently published on the CO_(2)absorption by AAILs remains limited.In addition,researchers have differing opinions on the AAILs/CO_(2)reaction mechanisms.Therefore,this review provides a thorough overview of the reaction mechanisms and structure-activity relationships associated with AAILs for CO_(2)capture.Moreover,it outlines the research advancements in pure AAILs and their mixtures,including aqueous AAILs and AAIL-organic solvent mixtures.The effects of varying ionic structures and additives on the absorption properties of AAILs are examined in detail.In conclusion,although AAILs exhibit high CO_(2)absorption loading and possess numerous appealing characteristics,further research is essential to comprehensively evaluate their viability for large-scale CO_(2)capture from flue gas.展开更多
Background Cetobacterium somerae,a symbiotic microorganism resident in various fish intestines,is recognized for its beneficial effects on fish gut health.However,the mechanisms underlying the effects of C.somerae on ...Background Cetobacterium somerae,a symbiotic microorganism resident in various fish intestines,is recognized for its beneficial effects on fish gut health.However,the mechanisms underlying the effects of C.somerae on gut health remain unclear.In this experiment,we investigated the influence of C.somerae(CGMCC No.28843)on the growth performance,intestinal digestive and absorptive capacity,and intestinal structural integrity of juvenile grass carp(Ctenopharyngodon idella)and explored its potential mechanisms.Methods A cohort of 2,160 juvenile grass carp with an initial mean body weight of 11.30±0.01 g were randomly allocated into 6 treatment groups,each comprising 6 replicates(60 fish per replicate).The experimental diets were supplemented with C.somerae at graded levels of 0.00(control),0.68×10^(9),1.35×10^(9),2.04×10^(9),2.70×10^(9),and 3.40×10^(9)cells/kg feed.Following a 10-week experimental period,biological samples were collected for subsequent analyses.Results Dietary supplementation with C.somerae at 1.35×10^(9)cells/kg significantly enhanced growth performance,intestinal development,and nutrient retention rate in juvenile grass carp(P<0.05).The treatment resulted in increased intestinal acetic acid concentration and enhanced activities of digestive enzymes and brush border enzymes(P<0.05).Furthermore,it reduced intestinal permeability(P<0.05),preserved tight junctions(TJ)ultrastructural integrity,and increased the expression of TJ and adherens junctions(AJ)biomarkers at both protein and transcriptional levels(P<0.05).Mechanistically,these effects may be correlated with enhanced antioxidant capacity and coordinated modulation of the RhoA/ROCK,Sirt1,and PI3K/AKT signaling pathways.The appropriate supplementation levels,based on weight gain rate,feed conversion ratio,the activity of serum diamine oxidase and the content of lipopolysaccharide,were 1.27×10^(9),1.27×10^(9),1.34×10^(9)and 1.34×10^(9)cells/kg,respectively.Conclusions C.somerae improved intestinal digestive and absorptive capacity of juvenile grass carp,maintained intestinal structural integrity,and thus promoted their growth and development.This work demonstrates the potential of C.somerae as a probiotic for aquatic animals and provides a theoretical basis for its utilization in aquaculture.展开更多
Taking absorptive capacity effects on research spillovers into consideration, this paper focuses on the R＆D investment decisions and the output decisions of labor-managed firms. Based on the general model of the cost...Taking absorptive capacity effects on research spillovers into consideration, this paper focuses on the R＆D investment decisions and the output decisions of labor-managed firms. Based on the general model of the cost-reducing R＆D, the strategic interactions of output and R＆D investment between labor-managed firms in a duopoly are analyzed. Moreover, the impact of absorptive capacity effects on optimal output in the production stage is discussed. In the R＆D stage, the impacts of absorptive capacity effects on the equilibrium R＆D investment in cooperative and non-cooperative R＆D are analyzed. Finally, the R＆D strategy of labor-managed firms is compared with the behavior of profit-maximizing firms. The results show that equilibrium R＆D investment is always higher than that in the exogenous spillover rate, which is similar to the behavior of the profit-maximizing firms. However, unlike the profit-maximizing firms, the impact of the absorptive capacity that affects the relationship between the optimal output and its own（rival＇ s）R＆D is shown to be dependent upon a return-to-scale of the production.展开更多
[Objective] This study aimed to determine the effect of rare earth biological regulator LaCl3 on the absorptive capacity to formaldehyde of four indoor ornamental plants, and to screen out the plant whose absorptive c...[Objective] This study aimed to determine the effect of rare earth biological regulator LaCl3 on the absorptive capacity to formaldehyde of four indoor ornamental plants, and to screen out the plant whose absorptive capacity to formaldehyde can be increased most greatly by LaCl3. [Method] Effect of LaCl3 on absorptive capacity to formaldehyde of four indoor ornamental plants was studied through fumigating in laboratory. Simultaneously, the indoor ornamental plant, which could significantly en- hance the degradation capacity of formaldehyde, was screened out to study the physiological and biochemical mechanisms of formaldehyde resistance. [Result] The ability to absorb formaldehyde of four indoor ornamental plants was enhanced by dif- ferent ranges after spraying with LaCl3 at suitable concentrations. The ability to ab- sorb formaldehyde of Hedera nepalensis var. sinensis, Chlorophytum comosum, Scindapsus aureun and Sansevieria trifasciata increased by 15.16%, 4.72%, 19.75% and 7.68%, respectively. In the four indoor ornamental plants, the capacity of S. au- reun to absorb formaldehyde was greatly improved by spraying LaCl3. When S. au- reun was stressed by formaldehyde, its chlorophyll content decreased by 39.87%, membrane permeability, MDA accumulation and POD activity increased by 8.17%, 56.92%, and 11.32%, respectively. However, compared the pre-spraying group with the no-spraying group under formaldehyde stress, chlorophyll content of S. aureun reduced less, membrane permeability and MDA cumulative both increased less, but POD activity increased more. [Conclusion] The formaldehyde absorption capacity of S. aureun was mostly improved after LaCl3 was sprayed.展开更多
A silylated melamine sponge(SMS)was prepared by two simple steps,namely,immersion and dehydration of a melamine sponge coated with methyltrichlorosilane.The silylated structure of SMS was characterized by FT-IR(Fourie...A silylated melamine sponge(SMS)was prepared by two simple steps,namely,immersion and dehydration of a melamine sponge coated with methyltrichlorosilane.The silylated structure of SMS was characterized by FT-IR(Fourier-transform infrared)spectroscopy,SEM(Scanning electron microscopy)and in terms of water contact angles.Its oil-water absorption and separation capacities were measured by FT-IR and UV-visible spectrophoto-metry.The experimental results have shown that oligomeric silanol covalently bonds by Si-N onto the surface of melamine sponge skeletons.SMS has shown superhydrophobicity with a water contact angle exceeding 150°±1°,a better separation efficiency with regard to diesel oil(by 99.31%(wt/wt%)in oil-water mixture and even up to 99.99%(wt/wt%)for diesel oil in its saturated aqueous solution.Moreover,SMS inherited the intrinsicflame retardancy of the melamine sponge.In general,SMS has shown superhydrophobicity,high porosity,excellent selectivity,remarkable recyclability,and better absorption capacity for various oils and organic solvents,and a high separation efficiency for oil in saturated aqueous solutions.展开更多
[Objective] This study was to analyze LaCl3 sprayed onto Scindapsus au- reus on Chlorophyll content and plasmamembrane permeability of leaves of Scindap- sus aureus, in order to determinate a suitable dosage of LaCl3....[Objective] This study was to analyze LaCl3 sprayed onto Scindapsus au- reus on Chlorophyll content and plasmamembrane permeability of leaves of Scindap- sus aureus, in order to determinate a suitable dosage of LaCl3. [Method] With Scindapsus aureus as the test subject, 110 households of 20 communities in the New District of Nantong were selected to investigate formaldehyde concentration in indoor air; and effect of LaCl3 on absorptive capacity to formaldehyde of Scindapsus aureus was studied through fumigating in laboratory. Simultaneously, its physiological and biochemical mechanism of formaldehyde resistance was studied. [Result] The re- sults showed that formaldehyde pollution of indoor air was serious in the New District of Nantong, and the degree of pollution was related to the time after decoration. The suitable concentration of LaCl3 for Scindapsus aureus was 20 mg/L. The ability to ab- sorb formaldehyde of Scindapsus aureus, which was calculated by per unit leaf area, was enhanced after spraying the suitable concentration of LaCl3 by 19.75%. When Scindapsus aureus was stressed by formaldehyde, chlorophyll content decreased by 39.87%, membrane permeability and cumulative MDA amount increased by 8.17% and 56.92%, respectively, and POD activity increased by 11.32%. However, by com- paring the group pre-sprayed with LaCl3 and the group not sprayed with LaCl3 under formaldehyde stress, chlorophyll content of Scindapsus aureus reduced lessly, mem- brane permeability and MDA both increased lessly, while POD activity increased more. [Conclusion] This study provides a new thinking direction for broadening of rare earth application and control measures of indoor air pollution.展开更多
Aqueous 1,8-diamino-p-menthane （KIER-C3） and commercially available amine solutions were tested for CO2 absorption. A 2-amino-2-methyl-1-propanol （AMP） solution with an addition of KIER-C3 showed 9.3% and 31.6% hi...Aqueous 1,8-diamino-p-menthane （KIER-C3） and commercially available amine solutions were tested for CO2 absorption. A 2-amino-2-methyl-1-propanol （AMP） solution with an addition of KIER-C3 showed 9.3% and 31.6% higher absorption rate for CO2 than the AMP solution with an addition of monoethanolamine （MEA） and ammonia （NH3）, respectively. The reaction rate constant for CO2 absorption by the AMP/KIER-C3 solution was determined by the following equation： k2,AMP/C3 = 7.702×106 exp （-2248.03/T）. A CO2 loading ratio of the AMP/KIER-C3 solution was also 2 and 3.4-times higher than that of the AMP/NH3 solution and the AMP/MEA solution, respectively. Based on the experimental results, KIER-C3 may be used as an excellent additive to increase CO2 absorption capability of AMP.展开更多
The main objective of this paper is that of surveying both theoretic and econometric models exploring the existence of knowledge spillovers and quantifying firm＇s ability to identify, assimilate, and exploit existing...The main objective of this paper is that of surveying both theoretic and econometric models exploring the existence of knowledge spillovers and quantifying firm＇s ability to identify, assimilate, and exploit existing information （absorptive capacity）. In so doing, we explore different methodologies through which we may analyze the knowledge transmission： both the production function approach and the knowledge function approach. In order to construct the spillover stocks, different dimensions are considered： geographic and technological.展开更多
Adsorbents with three-dimensional porous structures have gained widespread attention due to their unique characteristics,including a large surface area,high porosity,and excellent absorption capacity.One of the produc...Adsorbents with three-dimensional porous structures have gained widespread attention due to their unique characteristics,including a large surface area,high porosity,and excellent absorption capacity.One of the products is the wood sponge.The key to successfully producing wood sponges lies in an optimal multistage delignification process,which is particularly influenced by wood species,solvent,time,and temperature.The aim of this research was to analyze the characteristics of wood sponge derived from sengon wood(Falcataria moluccana Miq.)after multistage delignification.The process involved delignification using NaOH and Na_(2)SO_(3) solutions at 100℃ for 8,9 and 10 h,followed by further delignification in H_(2)O_(2) solution at 100℃ for 1,2,3,and 4 h.The samples were then frozen at -20℃ for 24 h and freeze-dried at -53℃ for 48 h.The results showed that wood sponges treated at 100℃ exhibited lower density,larger pore diameters,brighter color,and superior absorption capacity compared to untreated wood and sponges treated at room temperature for 24 h.FTIR analysis confirmed a decrease in wavelength between 1032–1035 cm^(-1),indicating the degradation of hemicellulose and lignin.XRD analysis revealed that crystallinity increased as amorphous content decreased with prolonged delignification.The wood sponges demonstrated good porosity,with an absorption capacity ranging from 0.65 to 2.24 g/g.The optimal treatment suggested in this research was multistage delignification using NaOH and Na_(2)SO_(3) solution for 10 h,followed by a 1 h treatment with H_(2)O_(2) solution.展开更多
Triply periodic minimal surface(TPMS)structures,characterized by special repeating 3D surface periodically with an average curvature of zero in threedimensional directions,have a wide range of applications.Laser powde...Triply periodic minimal surface(TPMS)structures,characterized by special repeating 3D surface periodically with an average curvature of zero in threedimensional directions,have a wide range of applications.Laser powder bed fusion(LPBF)technique,as a type of additive manufacturing techniques,provides the capability to fabricate such complex-shaped porous TPMS structures.In this study,Ti6Al4V G-sheet TPMS structures with various unit cell sizes were fabricated using LPBF to investigate the structural and material anisotropy and their effects on the anisotropy in energy absorption capacity by combining the finite element simulations and experimental analysis.The results showed that the TPMS structures can be successfully fabricated using LPBF,although the sheet thickness exceeds the designed values,with deviation decreasing as the unit cell size increases from 2 to 4 mm.The inherent anisotropy during the LPBF process results in variations in structural dimension,materials characteristics,and energy absorption capacity between directions parallel and perpendicular to the build direction.The anisotropic ratio of the LPBFed Ti6Al4V G-sheet TPMS structures increases from 1.5 to 2.2 in the structural dimension and from 2.8 to 3.3 in specific energy absorption per unit mass(SEA_(m))respectively with decreasing the unit cell size from 4 to 2 mm.The anisotropy of SEA_(m) primarily originates from the coupling effects of anisotropic dimensions and material properties in the LPBFed G-sheet TPMS structure.Among these factors,anisotropic material properties play a more significant role compared to dimensional anisotropy.展开更多
This paper focuses on how technology services can help small and medium-sized enterprises(SMEs)overcome the digital transformation dilemma of“cannot transform(lack of know-how),dare not transform(fear of risk),and ha...This paper focuses on how technology services can help small and medium-sized enterprises(SMEs)overcome the digital transformation dilemma of“cannot transform(lack of know-how),dare not transform(fear of risk),and have no money to transform(lack of funds).”Using literature analysis and multiple case comparisons,the study summarizes five major categories of technology services:technical support,consulting and planning,training and empowerment,resource integration,and financing connectivity.It constructs a“service–capability–performance”catalytic framework.Tracking of 58 enterprises in the Yangtze River Delta reveals that resource integration contributes the most to digital maturity,with absorptive capacity playing a significant mediating role;the configuration of“high technology services+high absorptive capacity+high environmental dynamism”is a sufficient condition for high transformation performance.Based on these findings,countermeasures are proposed,including improving the technology service system,strengthening government-industry-academia collaboration,and optimizing funding and talent supply,providing replicable experience for SMEs,governments,and technology service institutions.展开更多
Lost circulation of drilling fluid is one of the most common engineering problems in the drilling process of fractured formations.In this study,an oil-absorbing polymer gel synthesized using compound monomers with rig...Lost circulation of drilling fluid is one of the most common engineering problems in the drilling process of fractured formations.In this study,an oil-absorbing polymer gel synthesized using compound monomers with rigid and flexible chains was applied to control the oil-based drilling fluid loss while drilling.The microstructure,oil-absorbing performance,and plugging performance the gel was investigated.A large number of dense pores on the surface of the gel were observed,which allowed the oil molecules to enter the internal space of the gel.The initial oil absorption capacity of the gel was fast,and it increased with the increase in the temperature and decrease in the particle size,reaching 20.93 g/g at140℃.At a high temperature of 140℃,the bearing pressure capacity of the gel formula containing particles of different particle sizes reached 7.6 MPa for a fracture of a width of 3 mm,showing that the oil-absorbing gel have excellent plugging performance at high temperature.Plugging mechanism of the gel was investigated through visualized fracture plugging experiments.Results show that the dynamic migratio n,particle-swelling,particle-bridging,particle-aggregation,deformation-filling,and compaction-plugging contribute to the whole lost circulation control process,reflecting that the plugging performance can be effectively enhanced by improving the aggregation and filling degrees of the gel with different particle sizes.展开更多
Tourism in mountainous regions is a significant source of revenue generation. However, it has also been associated with many adverse environmental consequences. This study aims at assessing the negative impacts of the...Tourism in mountainous regions is a significant source of revenue generation. However, it has also been associated with many adverse environmental consequences. This study aims at assessing the negative impacts of the incessant upsurge in tourism development on the physical environment of Mussoorie, a well-known mountain tourist destination in India. The impact indicators for the region were identified and assessed by qualitative and quantitative analysis of field observations. The observations indicated the aggravation of traffic congestion, atmospheric pollution, undisposed solid waste, water scarcity and infrastructure unavailability as the prevalent issues, especially during the peak tourist months. The extent of the consequential damage to the environment was evaluated by conducting an assessment of tourism-induced human disturbance on the natural landscape of the town. Slope, slope aspect, vegetation cover, road network and drainage network were incorporated as thedetermining landscape attributes to prepare thematic maps of landscape quality(perceivable intrinsic properties) and landscape fragility(vulnerability to anthropogenic disturbances) using GIS technique. An absorption capacity map was finally prepared to characterize the study area into regions of different conservation needs. The results identified the need for planning appropriate preservation strategies for different tourist places in the town. The study can be used by the policy makers for implementing the regulatory measures against potential disturbances due to mass-tourism.展开更多
Development of modified plastics has been studied through the LDPE-acylated starch blend films to examine the effect of different acyl groups and degrees of substitution （DS） on properties of films. Corn starch was ...Development of modified plastics has been studied through the LDPE-acylated starch blend films to examine the effect of different acyl groups and degrees of substitution （DS） on properties of films. Corn starch was modified with acetyl and hutyryl groups and films were prepared by blending acylated starch with low density polyethylene （LDPE）. Systematic studies were done to observe the effect of acyl groups, DS and starch concentration on the properties and biodegradability of the blend films. It was observed that blend films containing 5% acetylated and butyrylated starches of high DS （2.5, 1.7） maintained 75% and 83% of tensile strength of LDPE films. Thermal analysis results indicated that acetylated and butyrylated starch blend films decomposed at 370℃ and 389℃ which were higher than the decomposition temperature of native starch film （349℃）. Scanning electron micrographs of blend films containing high DS acylated starch showed well dispersed starch particles due to improvement in dispersion between starch and LDPE. Water absorption capacity of high DS acetylated and butyrylated starch blend films （4.18% and 3.76%, respectively） was lower than that of native starch films （5%）. This study has an advantage because of blown films prepared can be integrated with the present manufacturing systems without any other requirement.展开更多
A new kind of composite buffering material was made by filling the voids of honeycomb paperboard with polyurethane. Drop tests were performed to evaluate the dynamic energy absorption capacity of the material. Based o...A new kind of composite buffering material was made by filling the voids of honeycomb paperboard with polyurethane. Drop tests were performed to evaluate the dynamic energy absorption capacity of the material. Based on the tests results, we analyzed the mechanical behaviors of the material under different conditions and obtained the inherent influencing laws of some factors on the material＇s dynamic buffering performance. It was shown that the dynamic buffering performance varied directly with impact velocity, and inversely with the void diameter, thickness and buffeting area of the composite material.展开更多
This work investigated and quantified the physicomechanical properties of flat-pressed wood plastic composites produced with recycled polyethylene terephthalate, recycled polyethylene and sawdust derived from selected...This work investigated and quantified the physicomechanical properties of flat-pressed wood plastic composites produced with recycled polyethylene terephthalate, recycled polyethylene and sawdust derived from selected tropical timbers, namely, Nauclea diderrichii, Brachystegia eurycoma, Erythrophleum suaveolens and Prosopis africana, for possible utilization in the wood industry. The compounding of the polymer blends of the precursor plastics, namely recycled PET (rPET) and recycled PE (rPE) with the sawdust (SD) from the selected timbers to produce the desired wood rPET/rPE composites was carried out via the flat press method. The characterization of the physicomechanical properties of the wood plastic composites (WPCs) produced, such as the density, hardness, flexural strength, ultimate tensile strength, elongation %, thickness swelling and water absorption capacity was carried out using methods based mainly on the European Committee for Standardization (CEN) and the American Society for Testing Materials (ASTM) standards. The results of the investigation on the resultant composites indicated that changes in the SD content affected the density of flat-pressed WPCs in line with literature. Generally, it was observed that as wood dust increased and PET content decreased, the density of composites decreased with some deviations as expected probably due to the anisotropic nature of the wood fillers. The analysis of variance (ANOVA) revealed that there was a statistically significant variation in the wood composites of Nuclea diderichii based on the physicomechanical values as the p-value (0.020) obtained was less than the critical level of α = 0.05. It was also observed that the composite, Wood 1 Sample 5 (W<sub>1</sub>S<sub>5</sub>) which was composed of 40% rPE, 40% rPET and 20% SD (derived from Nuclea diderichii), had the highest percentage elongation (26.84%);the highest flexural strength (14.995 N/mm<sup>2</sup>) and possibly the least carbon footprint in the environment. These properties of W<sub>1</sub>S<sub>5</sub> suggest that it could therefore be the best option for the production of building materials like ceiling boards or floor skirting in the wood plastic composite industry. The results of these investigations have therefore indicated that the fabrication of WPCs from sawdust and rPET/rPE was technically feasible and had prospects for large scale production in the wood industry.展开更多
基金funded by the National Natural Science Foundation Research of China(No.41902127,41802157)the Shandong Provincial Natural Science Foundation,China(No.ZR2018BD015).
文摘This study aims to determine the variation and controlling factors of shale gas adsorption capacity in reservoirs in the Upper Ordovician Wufeng Formation and the Lower Silurian Longmaxi Formation(also referred to as the WF-LMX formations),South China.Based on data obtained using scanning helium ion microscopy(HIM)and nitrogen(N_(2))and methane(CH_(4))adsorption experiments,this study analyzed the organic pore heterogeneity of shales in the WF-LMX formations in well A and its effect on shale gas adsorption.Using the Frenkel-Halsey-Hill(FHH)model,data from N_(2) adsorption experiments were converted into fractal dimensions,which can reflect the complexity and heterogeneity of organic pores while also serving as a novel indicator for quantitatively assessing the pore structure complexity.The results indicate that shales in the WF-LMX formations in well A can be divided into two sections:(Ⅰ)the Wufeng Formation and the lower Longmaxi Formation(depths:ca.2871.0-2898.6 m),and(Ⅱ)the upper Longmaxi Formation(depths:<2871.0 m).Organic pores in Section Ⅰ typically exhibit complex internal structures,coarse surfaces,and interconnectivity,whereas those in Section Ⅱ are simple,smooth,and isolated.Moreover,the former possesses larger specific surface areas(SSAs)than the latter.A fractal analysis reveals that organic pores in the shale sequence can be classified into micropores(<2 nm),mesopores(2-10 nm),and macropores(>10 nm).The calculated fractal dimensions show greater heterogeneity of organic pores,especially macropores,in Section Ⅰ compared to Section Ⅱ.The results also reveal that organic macropores are the primary pores controlling the SSAs of organic pores in shale reservoirs in the WF-LMX formations.Organic pores in Section Ⅰ manifest a superior shale gas adsorption capacity compared to Section Ⅱ.The heterogeneity of organic pores might affect the adsorption capacity of shales in the formations.Generally,organic macropores in Section Ⅰ of the shale sequence exhibit more complex structures and larger SSAs,leading to a stronger absorption capacity of shale reservoirs in Section Ⅰ compared to Section Ⅱ.
基金Supported by Tobacco Project of Changsha Branch of Hunan Tobacco Corporation(CYKJ2014-01)~~
文摘[Objective] This study aimed to analyze the differences in absorption capacity of different flue-cured tobacco cultivars for chromium （Cr）, arsenic （As）, cadmium （Cd）, lead （Pb）, mercury （Hg） and copper （Cu）. [Method] With 4 flue-cured tobacco cultivars as the experimental materials, their absorption capacity for 6 kinds of heavy metals was compared by pot experiment. [Result] There were great differences in absorption capacity of different flue-cured tobacco cultivars for the six kinds of heavy metals. According to the absorption capacity of different flue-cured tobacco cultivars for the heavy metals, the six heavy metals could be classified into three categories. The first category included only Cd with average enrichment coefficient of 8.564; the second category included Hg with average enrichment coefficient of 0.753; and the third category included Cr, As, Pb and Cu with average enrichment coefficients below or equivalent to 0.114. [Conclusion] The absorption capacity of different flue-cured tobacco cultivars for heavy metals was grasped by this study, thereby providing reference data for screening of high-yielding and high-quality flue-cured tobacco cultivars.
文摘a firm＇ s absorption capacity is a key factor to affect the knowledge transfer in ERP implementation, which influences the implementation of ERP By involving the subject - the ERP implementation of enterprise, ERP implementation is mainly the knowledge absorption of enterprise from the implementation service provider. It analyzes the factors that influence the absorption capacity in the implementation of Deluding the characteristics of the internal and external and knowledge itself, which promote the successful implementation of ERP.
基金financially supported by the National Natural Science Foundation of China(Nos.21171018 and 51271021)the State Key Laboratory for Advanced Metals and Materials。
文摘This study investigated the microstructure and hydrogen absorption properties of a rare-earth high-entropy alloy(HEA),YGdTbDyHo.Results indicated that the YGdTbDyHo alloy had a microstructure of equiaxed grains,with the alloy elements distributed homogeneously.Upon hydrogen absorption,the phase structure of the HEA changed from a solid solution with an hexagonal-close-packed(HCP)structure to a high-entropy hydride with an faced-centered-cubic(FCC)structure without any secondary phase precipitated.The alloy demonstrated a maximum hydrogen storage capacity of 2.33 H/M(hydrogen atom/metal atom)at 723 K,with an enthalpy change(ΔH)of-141.09 kJ·mol^(-1)and an entropy change(ΔS)of-119.14 J·mol^(-1)·K^(-1).The kinetic mechanism of hydrogen absorption was hydride nucleation and growth,with an apparent activation energy(E_(a))of 20.90 kJ·mol^(-1).Without any activation,the YGdTbDyHo alloy could absorb hydrogen quickly(180 s at 923 K)with nearly no incubation period observed.The reason for the obtained value of 2.33 H/M was that the hydrogen atoms occupied both tetrahedral and octahedral interstices.These results demonstrate the potential application of HEAs as a high-capacity hydrogen storage material with a large H/M ratio,which can be used in the deuterium storage field.
基金supported by the Natural Science Foundation of Shanghai(Grant No.24ZR1426200)the support from the Key Program of the National Natural Science Foundation of China(Grant No.52236004)。
文摘Carbon dioxide(CO_(2))is the predominant greenhouse gas in the Earth’s atmosphere and plays a crucial role in global warming.Given the inherent limitations of monoethanolamine absorbents in current commercial large-scale CO_(2)capture applications,amino acid ionic liquids(AAILs)have garnered extensive interest in this field due to their adjustable structure,low volatility,high thermal stability,and significant absorption capacity.However,the number of comprehensive reviews recently published on the CO_(2)absorption by AAILs remains limited.In addition,researchers have differing opinions on the AAILs/CO_(2)reaction mechanisms.Therefore,this review provides a thorough overview of the reaction mechanisms and structure-activity relationships associated with AAILs for CO_(2)capture.Moreover,it outlines the research advancements in pure AAILs and their mixtures,including aqueous AAILs and AAIL-organic solvent mixtures.The effects of varying ionic structures and additives on the absorption properties of AAILs are examined in detail.In conclusion,although AAILs exhibit high CO_(2)absorption loading and possess numerous appealing characteristics,further research is essential to comprehensively evaluate their viability for large-scale CO_(2)capture from flue gas.
基金financially supported by the earmarked fund for the earmarked fund for CARS(CARS-45)National Science Fund for Distinguished Young Scholars of China(32425056)+1 种基金the National Key R&D Program of China(2023YFD2400600)Sichuan Innovation Team of National Modern Agricultural Industry Technology System(SCCXTD-2024-16).
文摘Background Cetobacterium somerae,a symbiotic microorganism resident in various fish intestines,is recognized for its beneficial effects on fish gut health.However,the mechanisms underlying the effects of C.somerae on gut health remain unclear.In this experiment,we investigated the influence of C.somerae(CGMCC No.28843)on the growth performance,intestinal digestive and absorptive capacity,and intestinal structural integrity of juvenile grass carp(Ctenopharyngodon idella)and explored its potential mechanisms.Methods A cohort of 2,160 juvenile grass carp with an initial mean body weight of 11.30±0.01 g were randomly allocated into 6 treatment groups,each comprising 6 replicates(60 fish per replicate).The experimental diets were supplemented with C.somerae at graded levels of 0.00(control),0.68×10^(9),1.35×10^(9),2.04×10^(9),2.70×10^(9),and 3.40×10^(9)cells/kg feed.Following a 10-week experimental period,biological samples were collected for subsequent analyses.Results Dietary supplementation with C.somerae at 1.35×10^(9)cells/kg significantly enhanced growth performance,intestinal development,and nutrient retention rate in juvenile grass carp(P<0.05).The treatment resulted in increased intestinal acetic acid concentration and enhanced activities of digestive enzymes and brush border enzymes(P<0.05).Furthermore,it reduced intestinal permeability(P<0.05),preserved tight junctions(TJ)ultrastructural integrity,and increased the expression of TJ and adherens junctions(AJ)biomarkers at both protein and transcriptional levels(P<0.05).Mechanistically,these effects may be correlated with enhanced antioxidant capacity and coordinated modulation of the RhoA/ROCK,Sirt1,and PI3K/AKT signaling pathways.The appropriate supplementation levels,based on weight gain rate,feed conversion ratio,the activity of serum diamine oxidase and the content of lipopolysaccharide,were 1.27×10^(9),1.27×10^(9),1.34×10^(9)and 1.34×10^(9)cells/kg,respectively.Conclusions C.somerae improved intestinal digestive and absorptive capacity of juvenile grass carp,maintained intestinal structural integrity,and thus promoted their growth and development.This work demonstrates the potential of C.somerae as a probiotic for aquatic animals and provides a theoretical basis for its utilization in aquaculture.
基金The National Natural Science Foundation of China(No.70671024)Annual Research Results in Zhejiang Federation of Humanities and Social Sciences Circles(No.08N40)
文摘Taking absorptive capacity effects on research spillovers into consideration, this paper focuses on the R＆D investment decisions and the output decisions of labor-managed firms. Based on the general model of the cost-reducing R＆D, the strategic interactions of output and R＆D investment between labor-managed firms in a duopoly are analyzed. Moreover, the impact of absorptive capacity effects on optimal output in the production stage is discussed. In the R＆D stage, the impacts of absorptive capacity effects on the equilibrium R＆D investment in cooperative and non-cooperative R＆D are analyzed. Finally, the R＆D strategy of labor-managed firms is compared with the behavior of profit-maximizing firms. The results show that equilibrium R＆D investment is always higher than that in the exogenous spillover rate, which is similar to the behavior of the profit-maximizing firms. However, unlike the profit-maximizing firms, the impact of the absorptive capacity that affects the relationship between the optimal output and its own（rival＇ s）R＆D is shown to be dependent upon a return-to-scale of the production.
基金Supported by the Qing Lan Project for Excellent Young Key Teachers of Colleges and Universities of Jiangsu Province in 2010 [Jiangsu Teacher(2010)27]Undergraduate Practice and Innovation Training Program of Colleges and Universities of Jiangsu Province in 2010 and 2012 [Jiangsu Education Department(2010)27,Jiangsu Education Department Office(2012)3]+2 种基金Fund of Jiangsu R&D Center for Engineering Technology of Preventing and Treating Rural Environmental Pollution [(2011)13]Science and Technology Program of Nantong City(DE2009006S2009019)~~
文摘[Objective] This study aimed to determine the effect of rare earth biological regulator LaCl3 on the absorptive capacity to formaldehyde of four indoor ornamental plants, and to screen out the plant whose absorptive capacity to formaldehyde can be increased most greatly by LaCl3. [Method] Effect of LaCl3 on absorptive capacity to formaldehyde of four indoor ornamental plants was studied through fumigating in laboratory. Simultaneously, the indoor ornamental plant, which could significantly en- hance the degradation capacity of formaldehyde, was screened out to study the physiological and biochemical mechanisms of formaldehyde resistance. [Result] The ability to absorb formaldehyde of four indoor ornamental plants was enhanced by dif- ferent ranges after spraying with LaCl3 at suitable concentrations. The ability to ab- sorb formaldehyde of Hedera nepalensis var. sinensis, Chlorophytum comosum, Scindapsus aureun and Sansevieria trifasciata increased by 15.16%, 4.72%, 19.75% and 7.68%, respectively. In the four indoor ornamental plants, the capacity of S. au- reun to absorb formaldehyde was greatly improved by spraying LaCl3. When S. au- reun was stressed by formaldehyde, its chlorophyll content decreased by 39.87%, membrane permeability, MDA accumulation and POD activity increased by 8.17%, 56.92%, and 11.32%, respectively. However, compared the pre-spraying group with the no-spraying group under formaldehyde stress, chlorophyll content of S. aureun reduced less, membrane permeability and MDA cumulative both increased less, but POD activity increased more. [Conclusion] The formaldehyde absorption capacity of S. aureun was mostly improved after LaCl3 was sprayed.
基金funded by Qingyang Science and Technology Support Project(KT2019-03)。
文摘A silylated melamine sponge(SMS)was prepared by two simple steps,namely,immersion and dehydration of a melamine sponge coated with methyltrichlorosilane.The silylated structure of SMS was characterized by FT-IR(Fourier-transform infrared)spectroscopy,SEM(Scanning electron microscopy)and in terms of water contact angles.Its oil-water absorption and separation capacities were measured by FT-IR and UV-visible spectrophoto-metry.The experimental results have shown that oligomeric silanol covalently bonds by Si-N onto the surface of melamine sponge skeletons.SMS has shown superhydrophobicity with a water contact angle exceeding 150°±1°,a better separation efficiency with regard to diesel oil(by 99.31%(wt/wt%)in oil-water mixture and even up to 99.99%(wt/wt%)for diesel oil in its saturated aqueous solution.Moreover,SMS inherited the intrinsicflame retardancy of the melamine sponge.In general,SMS has shown superhydrophobicity,high porosity,excellent selectivity,remarkable recyclability,and better absorption capacity for various oils and organic solvents,and a high separation efficiency for oil in saturated aqueous solutions.
基金Supported by Qing Lan Project for Outstanding Young Teachers in Higher Education Institutions of Jiangsu Province(SJS[2010]27)College Students’Innovative Entrepreneurial Training Program of Jiangsu Province in 2014(SJBG[2010]8)+2 种基金Funding Project for Rural Environment Pollution Control Engineering and Technological Research Center of Jiangsu Province(SJK[2011]13)Funding Project of Science and Technology Plan in Nantong City(HS2014025)First Petty Funding Project for Ecological Construction of Nantong City(TH[2014]33)~~
文摘[Objective] This study was to analyze LaCl3 sprayed onto Scindapsus au- reus on Chlorophyll content and plasmamembrane permeability of leaves of Scindap- sus aureus, in order to determinate a suitable dosage of LaCl3. [Method] With Scindapsus aureus as the test subject, 110 households of 20 communities in the New District of Nantong were selected to investigate formaldehyde concentration in indoor air; and effect of LaCl3 on absorptive capacity to formaldehyde of Scindapsus aureus was studied through fumigating in laboratory. Simultaneously, its physiological and biochemical mechanism of formaldehyde resistance was studied. [Result] The re- sults showed that formaldehyde pollution of indoor air was serious in the New District of Nantong, and the degree of pollution was related to the time after decoration. The suitable concentration of LaCl3 for Scindapsus aureus was 20 mg/L. The ability to ab- sorb formaldehyde of Scindapsus aureus, which was calculated by per unit leaf area, was enhanced after spraying the suitable concentration of LaCl3 by 19.75%. When Scindapsus aureus was stressed by formaldehyde, chlorophyll content decreased by 39.87%, membrane permeability and cumulative MDA amount increased by 8.17% and 56.92%, respectively, and POD activity increased by 11.32%. However, by com- paring the group pre-sprayed with LaCl3 and the group not sprayed with LaCl3 under formaldehyde stress, chlorophyll content of Scindapsus aureus reduced lessly, mem- brane permeability and MDA both increased lessly, while POD activity increased more. [Conclusion] This study provides a new thinking direction for broadening of rare earth application and control measures of indoor air pollution.
基金financially supported by the Brain Korea 21 Project in 2012the Energy Efficiency & Resources of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No.2006CCD11P011A -21-3-010)
文摘Aqueous 1,8-diamino-p-menthane （KIER-C3） and commercially available amine solutions were tested for CO2 absorption. A 2-amino-2-methyl-1-propanol （AMP） solution with an addition of KIER-C3 showed 9.3% and 31.6% higher absorption rate for CO2 than the AMP solution with an addition of monoethanolamine （MEA） and ammonia （NH3）, respectively. The reaction rate constant for CO2 absorption by the AMP/KIER-C3 solution was determined by the following equation： k2,AMP/C3 = 7.702×106 exp （-2248.03/T）. A CO2 loading ratio of the AMP/KIER-C3 solution was also 2 and 3.4-times higher than that of the AMP/NH3 solution and the AMP/MEA solution, respectively. Based on the experimental results, KIER-C3 may be used as an excellent additive to increase CO2 absorption capability of AMP.
文摘The main objective of this paper is that of surveying both theoretic and econometric models exploring the existence of knowledge spillovers and quantifying firm＇s ability to identify, assimilate, and exploit existing information （absorptive capacity）. In so doing, we explore different methodologies through which we may analyze the knowledge transmission： both the production function approach and the knowledge function approach. In order to construct the spillover stocks, different dimensions are considered： geographic and technological.
基金funded by New Energy and Industrial Technology Development Organization of Japan(NEDO)—NET ZERO EMISSION TA 2023 BATCH-2—with the Grant Number 28/Ⅲ.5/HK/2023Research Program by Research Organization of Nanotechnology and Materials,National Research and Innovation Agency(Grant Number B-1484/Ⅲ.10/TK.01.00/2/2024)Research Program by Research Assistant,National Research and Innovation Agency(Grant Number B-6932/Ⅱ.5/S1.06.01/9/2023).
文摘Adsorbents with three-dimensional porous structures have gained widespread attention due to their unique characteristics,including a large surface area,high porosity,and excellent absorption capacity.One of the products is the wood sponge.The key to successfully producing wood sponges lies in an optimal multistage delignification process,which is particularly influenced by wood species,solvent,time,and temperature.The aim of this research was to analyze the characteristics of wood sponge derived from sengon wood(Falcataria moluccana Miq.)after multistage delignification.The process involved delignification using NaOH and Na_(2)SO_(3) solutions at 100℃ for 8,9 and 10 h,followed by further delignification in H_(2)O_(2) solution at 100℃ for 1,2,3,and 4 h.The samples were then frozen at -20℃ for 24 h and freeze-dried at -53℃ for 48 h.The results showed that wood sponges treated at 100℃ exhibited lower density,larger pore diameters,brighter color,and superior absorption capacity compared to untreated wood and sponges treated at room temperature for 24 h.FTIR analysis confirmed a decrease in wavelength between 1032–1035 cm^(-1),indicating the degradation of hemicellulose and lignin.XRD analysis revealed that crystallinity increased as amorphous content decreased with prolonged delignification.The wood sponges demonstrated good porosity,with an absorption capacity ranging from 0.65 to 2.24 g/g.The optimal treatment suggested in this research was multistage delignification using NaOH and Na_(2)SO_(3) solution for 10 h,followed by a 1 h treatment with H_(2)O_(2) solution.
基金financially supported by the Open Project Program of Chinese Scholar Tree Ridge State Key Laboratory(No.AF20240023)
文摘Triply periodic minimal surface(TPMS)structures,characterized by special repeating 3D surface periodically with an average curvature of zero in threedimensional directions,have a wide range of applications.Laser powder bed fusion(LPBF)technique,as a type of additive manufacturing techniques,provides the capability to fabricate such complex-shaped porous TPMS structures.In this study,Ti6Al4V G-sheet TPMS structures with various unit cell sizes were fabricated using LPBF to investigate the structural and material anisotropy and their effects on the anisotropy in energy absorption capacity by combining the finite element simulations and experimental analysis.The results showed that the TPMS structures can be successfully fabricated using LPBF,although the sheet thickness exceeds the designed values,with deviation decreasing as the unit cell size increases from 2 to 4 mm.The inherent anisotropy during the LPBF process results in variations in structural dimension,materials characteristics,and energy absorption capacity between directions parallel and perpendicular to the build direction.The anisotropic ratio of the LPBFed Ti6Al4V G-sheet TPMS structures increases from 1.5 to 2.2 in the structural dimension and from 2.8 to 3.3 in specific energy absorption per unit mass(SEA_(m))respectively with decreasing the unit cell size from 4 to 2 mm.The anisotropy of SEA_(m) primarily originates from the coupling effects of anisotropic dimensions and material properties in the LPBFed G-sheet TPMS structure.Among these factors,anisotropic material properties play a more significant role compared to dimensional anisotropy.
基金supported by Anhui Provincial Philosophy&Social Science Fund(AHSKY2023D12)Anqing Normal University Key Project Grant“Research on the Digital Interactive Development of Trade between China Railway Express and Countries along the Belt and Road Initiative”(SK202211ZD)。
文摘This paper focuses on how technology services can help small and medium-sized enterprises(SMEs)overcome the digital transformation dilemma of“cannot transform(lack of know-how),dare not transform(fear of risk),and have no money to transform(lack of funds).”Using literature analysis and multiple case comparisons,the study summarizes five major categories of technology services:technical support,consulting and planning,training and empowerment,resource integration,and financing connectivity.It constructs a“service–capability–performance”catalytic framework.Tracking of 58 enterprises in the Yangtze River Delta reveals that resource integration contributes the most to digital maturity,with absorptive capacity playing a significant mediating role;the configuration of“high technology services+high absorptive capacity+high environmental dynamism”is a sufficient condition for high transformation performance.Based on these findings,countermeasures are proposed,including improving the technology service system,strengthening government-industry-academia collaboration,and optimizing funding and talent supply,providing replicable experience for SMEs,governments,and technology service institutions.
基金financially supported by the National Natural Science Foundation of China(Grant 52074327,51991361)the Natural Science Foundation of Shandong Province,China(ZR2020QE107)
文摘Lost circulation of drilling fluid is one of the most common engineering problems in the drilling process of fractured formations.In this study,an oil-absorbing polymer gel synthesized using compound monomers with rigid and flexible chains was applied to control the oil-based drilling fluid loss while drilling.The microstructure,oil-absorbing performance,and plugging performance the gel was investigated.A large number of dense pores on the surface of the gel were observed,which allowed the oil molecules to enter the internal space of the gel.The initial oil absorption capacity of the gel was fast,and it increased with the increase in the temperature and decrease in the particle size,reaching 20.93 g/g at140℃.At a high temperature of 140℃,the bearing pressure capacity of the gel formula containing particles of different particle sizes reached 7.6 MPa for a fracture of a width of 3 mm,showing that the oil-absorbing gel have excellent plugging performance at high temperature.Plugging mechanism of the gel was investigated through visualized fracture plugging experiments.Results show that the dynamic migratio n,particle-swelling,particle-bridging,particle-aggregation,deformation-filling,and compaction-plugging contribute to the whole lost circulation control process,reflecting that the plugging performance can be effectively enhanced by improving the aggregation and filling degrees of the gel with different particle sizes.
基金Financial support provided to the first author from the Department of Science&Technology,Government of India under grant DST/INSPIRE FELLOWSHIP/2012/558
文摘Tourism in mountainous regions is a significant source of revenue generation. However, it has also been associated with many adverse environmental consequences. This study aims at assessing the negative impacts of the incessant upsurge in tourism development on the physical environment of Mussoorie, a well-known mountain tourist destination in India. The impact indicators for the region were identified and assessed by qualitative and quantitative analysis of field observations. The observations indicated the aggravation of traffic congestion, atmospheric pollution, undisposed solid waste, water scarcity and infrastructure unavailability as the prevalent issues, especially during the peak tourist months. The extent of the consequential damage to the environment was evaluated by conducting an assessment of tourism-induced human disturbance on the natural landscape of the town. Slope, slope aspect, vegetation cover, road network and drainage network were incorporated as thedetermining landscape attributes to prepare thematic maps of landscape quality(perceivable intrinsic properties) and landscape fragility(vulnerability to anthropogenic disturbances) using GIS technique. An absorption capacity map was finally prepared to characterize the study area into regions of different conservation needs. The results identified the need for planning appropriate preservation strategies for different tourist places in the town. The study can be used by the policy makers for implementing the regulatory measures against potential disturbances due to mass-tourism.
文摘Development of modified plastics has been studied through the LDPE-acylated starch blend films to examine the effect of different acyl groups and degrees of substitution （DS） on properties of films. Corn starch was modified with acetyl and hutyryl groups and films were prepared by blending acylated starch with low density polyethylene （LDPE）. Systematic studies were done to observe the effect of acyl groups, DS and starch concentration on the properties and biodegradability of the blend films. It was observed that blend films containing 5% acetylated and butyrylated starches of high DS （2.5, 1.7） maintained 75% and 83% of tensile strength of LDPE films. Thermal analysis results indicated that acetylated and butyrylated starch blend films decomposed at 370℃ and 389℃ which were higher than the decomposition temperature of native starch film （349℃）. Scanning electron micrographs of blend films containing high DS acylated starch showed well dispersed starch particles due to improvement in dispersion between starch and LDPE. Water absorption capacity of high DS acetylated and butyrylated starch blend films （4.18% and 3.76%, respectively） was lower than that of native starch films （5%）. This study has an advantage because of blown films prepared can be integrated with the present manufacturing systems without any other requirement.
基金Funded in part by the National Natural Science Foundation of China(No.51008306)
文摘A new kind of composite buffering material was made by filling the voids of honeycomb paperboard with polyurethane. Drop tests were performed to evaluate the dynamic energy absorption capacity of the material. Based on the tests results, we analyzed the mechanical behaviors of the material under different conditions and obtained the inherent influencing laws of some factors on the material＇s dynamic buffering performance. It was shown that the dynamic buffering performance varied directly with impact velocity, and inversely with the void diameter, thickness and buffeting area of the composite material.
文摘This work investigated and quantified the physicomechanical properties of flat-pressed wood plastic composites produced with recycled polyethylene terephthalate, recycled polyethylene and sawdust derived from selected tropical timbers, namely, Nauclea diderrichii, Brachystegia eurycoma, Erythrophleum suaveolens and Prosopis africana, for possible utilization in the wood industry. The compounding of the polymer blends of the precursor plastics, namely recycled PET (rPET) and recycled PE (rPE) with the sawdust (SD) from the selected timbers to produce the desired wood rPET/rPE composites was carried out via the flat press method. The characterization of the physicomechanical properties of the wood plastic composites (WPCs) produced, such as the density, hardness, flexural strength, ultimate tensile strength, elongation %, thickness swelling and water absorption capacity was carried out using methods based mainly on the European Committee for Standardization (CEN) and the American Society for Testing Materials (ASTM) standards. The results of the investigation on the resultant composites indicated that changes in the SD content affected the density of flat-pressed WPCs in line with literature. Generally, it was observed that as wood dust increased and PET content decreased, the density of composites decreased with some deviations as expected probably due to the anisotropic nature of the wood fillers. The analysis of variance (ANOVA) revealed that there was a statistically significant variation in the wood composites of Nuclea diderichii based on the physicomechanical values as the p-value (0.020) obtained was less than the critical level of α = 0.05. It was also observed that the composite, Wood 1 Sample 5 (W<sub>1</sub>S<sub>5</sub>) which was composed of 40% rPE, 40% rPET and 20% SD (derived from Nuclea diderichii), had the highest percentage elongation (26.84%);the highest flexural strength (14.995 N/mm<sup>2</sup>) and possibly the least carbon footprint in the environment. These properties of W<sub>1</sub>S<sub>5</sub> suggest that it could therefore be the best option for the production of building materials like ceiling boards or floor skirting in the wood plastic composite industry. The results of these investigations have therefore indicated that the fabrication of WPCs from sawdust and rPET/rPE was technically feasible and had prospects for large scale production in the wood industry.
