Based on split plot design method of field test,the impacts of supplemental irrigation based on soil moisture measurement and nitrogen use on winter wheat yield and nitrogen absorption and distribution were studied.Su...Based on split plot design method of field test,the impacts of supplemental irrigation based on soil moisture measurement and nitrogen use on winter wheat yield and nitrogen absorption and distribution were studied.Supplemental irrigation had three levels: 60%(W_1),70%(W_2) and 80%(W3) of the targeted relative water content at 0-40 cm of soil layer during jointing period of winter wheat.Nitrogen fertilization had three levels: not using nitrogen(N_0),using pure nitrogen of 195 kg/hm^2(N_(195)) and 255 kg/hm^2(N_(255)).Results showed that:(i)different supplemental irrigation and nitrogen fertilization significantly affected plant height and leaf area of winter wheat during key growth period.Under the same supplemental irrigation treatment,both plant height and leaf area of winter wheat showed as N_(255)> N_(195)> N_0(P <0.05).Plant height in N_(195) and N_(255)treatments was significantly higher than that in N_0 treatment,but there was not significant difference between N_(195) and N_(255)(P >0.05).Under the same nitrogen fertilization,plant height in W_2(569.4 m^3/hm^2) and W3(873.45 m^3/hm^2) treatments was significant higher than that in W_1(265.2 m^3/hm^2),but there was not significant difference between W_2 and W3(P >0.05).It illustrated that excessive nitrogen fertilization and supplemental irrigation did not significantly affect plant height and leaf area of winter wheat.(ii) Under the same nitrogen fertilization level,yield increase effect of winter wheat by supplemental irrigation showed a declining trend with nitrogen application amount increased.It illustrated that nitrogen fertilization and supplemental irrigation had certain critical values on the yield of winter wheat.When surpassing the critical value,the yield declined.When nitrogen fertilization amount was 195 kg/hm^2,and supplemental irrigation amount was 70% of field moisture capacity(569.4 m^3/hm^2),the highest yield 8500 kg/hm^2 could be obtained.(iii) During mature period of winter wheat,nitrogen accumulation amount of plant treated by nitrogen was significantly higher than that not treated by nitrogen(P <0.05).But under the treatments of W_2 and W3,nitrogen accumulation amount in N_(255) significantly declined when compared with N_(195)(P <0.05).Especially under W3(873.45 m^3/hm^2) level,nitrogen accumulation amount in N_(255) was even lower than N_0.Under the treatments of N_0 and N_(195),nitrogen accumulation amount of plant significantly increased with supplemental irrigation increased(P < 0.05).But under N_(255) treatment,there was not significant difference(P > 0.05).It illustrated that moderate supplemental irrigation and nitrogen fertilization could improve nitrogen absorption ability of winter wheat,but excessive supplemental irrigation and nitrogen fertilization were not favorable for plant's nitrogen absorption.(iv) Although the increase of supplemental irrigation during jointing period improved nitrogen absorption ability of winter wheat and promoted winter wheat absorbing more nitrogen,it inhibited nitrogen transferring and distributing to seed.Comprehensively considering growth condition of winter wheat and nitrogen risk condition,it is suggested that nitrogen application amount was 195 kg/hm^2,and supplemental irrigation reached 70% of field moisture capacity(569.4 m^3/hm^2),which could be as the suitable water and fertilizer use amounts in the region.展开更多
As an alternative to conventional encapsulation concepts for a double glass photovoltaic(PV)module,we introduce an innovative ionomer-based multi-layer encapsulant,by which the application of additional edge sealing t...As an alternative to conventional encapsulation concepts for a double glass photovoltaic(PV)module,we introduce an innovative ionomer-based multi-layer encapsulant,by which the application of additional edge sealing to prevent moisture penetration is not required.The spontaneous moisture absorption and desorption of this encapsulant and its raw materials,poly(ethylene-co-acrylic acid)and an ionomer,are analyzed under different climatic conditions in this work.The relative air humidity is thermodynamically the driving force for these inverse processes and determines the corresponding equilibrium moisture content(EMC).Higher air humidity results in a larger EMC.The homogenization of the absorbed water molecules is a diffusion-controlled process,in which temperature plays a dominant role.Nevertheless,the diffusion coefficient at a higher temperature is still relatively low.Hence,under normal climatic conditions for the application of PV modules,we believe that the investigated ionomer-based encapsulant can“breathe”the humidity:During the day,when there is higher relative humidity,it“inhales”(absorbs)moisture and restrains it within the outer edge of the module;then at night,when there is a lower relative humidity,it“exhales”(desorbs)the moisture.In this way,the encapsulant protects the cell from moisture ingress.展开更多
The Lop Nur dry salt lake,Xinjiang province,is charactered by typical physiognomy salt-crust,located in39.6-41.3N.latitude and 89.6-91.4E.longitude.The thickness of salt-crust is about from 20 cm to 100 cm,and
The water vapour resistance of clothing ensembles is not as commonly determined as dry thermal insulation. The measurement techniques are more complicated and the measurement values differ among laboratories. Due to c...The water vapour resistance of clothing ensembles is not as commonly determined as dry thermal insulation. The measurement techniques are more complicated and the measurement values differ among laboratories. Due to complicated moisture transfer process through clothing ensemble, the moisture absorbed and evaporated varies in transient and steady state phases depending on properties, thickness of clothing, and environmental conditions. The purpose of this study was to measure moisture gain inside hygroscopic underwear, and hydrophobic and permeable outer wear as a function of time, to investigate mass loss from ＂skin＂ as well as from the manikin, to quantify evaporative heat loss and total heat loss from the manikin, and to determine water vaponr resistance of clothing. Manikin Tore was used by wearing wet ＂skin＂ to simulate sweating condition. Moisture content in the inner garment gain shows an exponential relation against time. Moisture in the outer permeable layer shows little gain. On the contrary, mass loss directly from the wet skin decreases exponentially. The mass loss from the manikin is relatively stable throughout three test phases. The evaporative heat loss is about 2/3 of the total heat loss from the sweating manikin. While measuring the evaporative resistance of clothing ensembles with hygroscopic inner garment and permeable outer garment, unlike to measure ensembles with impermeable outer layer, one hour measurement time is enough to get relatively stable results. The variation between the 1^rt hour and the 3^nd hour is less than 5%. The length of transient period and measurement time is dependent on the permeability, thickness of clothing ensembles and environmental conditions.展开更多
The paper analyses the effect of stitch geometrical modality changing after moisture absorption on the porosity of knitted fabrics,and educes the formulas between porosity and stitch parameters.Regarding as the cell s...The paper analyses the effect of stitch geometrical modality changing after moisture absorption on the porosity of knitted fabrics,and educes the formulas between porosity and stitch parameters.Regarding as the cell stitch,the increasing of yarn diameter brings the porosity decreasing and the fabric shrinking in the wale direction.While the diameter keeps invariability,the yarn elongating brings the fabric humping up as well as the increasing porosity.The air-permeability experiments have been conducted to validate the theoretical analysis,and there is reasonable agreement between the theories and experiments.展开更多
We have been studying the function and structure of fatty acid-containing extracellular polysaccharides (FACEPS) produced by bacteria belonging to the genus Rhodococcus. In this study, we examined the relationships be...We have been studying the function and structure of fatty acid-containing extracellular polysaccharides (FACEPS) produced by bacteria belonging to the genus Rhodococcus. In this study, we examined the relationships between the structure and emulsifying, thickening, moisture-absorption, and moisture-retention capabilities of rhodococcal FACEPS using S-2 EPS produced by R. rhodochrous strain S-2. We prepared chemically deacylated S-2 EPS (DeAcyl S-2 EPS) and palmitoylated DeAcyl S-2 EPS (ReAcyl S-2 EPS), and compared them with native S-2 EPS. All of the properties were attenuated and recovered by deacylation and reacylation of S-2 EPS, respectively. These results suggest that the fatty acid moiety of rhodococcal FACEPS is involved in such functional properties. We also showed that palmitoylation improved the emulsifying, moisture-ab-sorption, and moisture-retention abilities of other acidic polysaccharides that are commercially available. These results suggest that the acidity of the polysaccharide backbone is at least partly responsible for the observed functionality of fatty acid-containing polysaccharides. To our knowledge, this is the first report on multifunctional property of an anionic polymer incorporating low amounts of hydrophobic residues. The present findings could be useful for the creation of new multifunctional surfactants from renewable raw materials for use in various industries, e.g., in cosmetics.展开更多
In the accompanying paper (Part 1), we showed that the fatty acid moiety and the acidity of the polysaccharide-backbone of a fatty acid-containing polysaccharide might be involved in its emul-sification, moisture abso...In the accompanying paper (Part 1), we showed that the fatty acid moiety and the acidity of the polysaccharide-backbone of a fatty acid-containing polysaccharide might be involved in its emul-sification, moisture absorption, and moisture retention abilities. In this study, we synthesized alkyl esterified poly-γ-glutamic acid (PGA) with various chain lengths and degrees of substitution of the alkyl moieties to examine how hydrophobic groups incorporated in the anionic polymer contribute to enhanced emulsification, moisture absorption, and moisture retention. With a low degree of alkylation of PGA, these abilities were drastically improved. To improve the moisture absorption of PGA, alkylation with a short chain length is effective in forming interspaces between PGA chains to trap water molecules. Hydrophobic-hydrophilic balance may also be important to improve the emulsification and moisture retention abilities of PGA alkylates. To the best of our knowledge, this is the first report of the relationship between the structure and the multifunctional abilities of an anionic polymer incorporated with a small amount of hydrophobic residue. PGA alkylates, as well as fatty acid-containing polysaccharides, have potential use as multifunctional surfactants throughout various industries.展开更多
An important property of moisture absorption and sweat discharge yarns is their water transport property. In the paper, two water transport models of moisture absorption and sweat discharge yarns were developed to inv...An important property of moisture absorption and sweat discharge yarns is their water transport property. In the paper, two water transport models of moisture absorption and sweat discharge yarns were developed to investigate the influence factors on their wicking rate. In parallel Column Pores Model, wicking rate is determined by the equivalent capillary radius R and length of the capillary tube L. In Pellets Accumulation Model, wicking rate is decided by the capillary radius r and length of the fiber unit assemble L0.展开更多
Composite materials are lightweight structures and have been wildly used in marine applications.A carbon composite structure usually absorbs moisture while in-service,which can significantly affect its properties,and ...Composite materials are lightweight structures and have been wildly used in marine applications.A carbon composite structure usually absorbs moisture while in-service,which can significantly affect its properties,and detriments the overall performance.We perform a detailed study on moisture absorption and diffusion of a carbon fibre reinforced vinyl ester resin composite system.Composite samples are immersed directly in four different solutions at a temperature of 37±0.5℃for 1444h.The moisture diffusion is analysed through the Fickian diffusion model;the diffusion parameters are subsequently determined from the gravimetric data.The moisture absorption and interaction with the composite constituents are then discussed.These indicate the fundamentals of the moisture absorption and diffusion within the carbon composite structure.展开更多
[Objective] This study aimed to determine the effects of supplemental irrigation on yield and nitrogen uptake in winter wheat. [Method] Three supplemental irrigation levels were set based on the target soil contents ...[Objective] This study aimed to determine the effects of supplemental irrigation on yield and nitrogen uptake in winter wheat. [Method] Three supplemental irrigation levels were set based on the target soil contents of 60%, 70% and 80%） at jointing stage of wheat. Moreover, three nitrogen levels （0, 195 and 255 kg/hm^2） were designed. The experimental plots were arranged fol owing a split-plot design. Zhoumai 18 was selected as the experimental material. [Result] Supplemental irrigation and nitrogen application in combination had significant or extremely significant effects on yield, yield components and nitrogen uptake in winter wheat. The interaction between irrigation and nitrogen fertilization had significant or extremely significant influence on the number of ears, number of grains per ear, 1 000-grain weight, grain yield and nitrogen accumulation in winter wheat. Under different combinations of supplemental irrigation and nitrogen application, the maximum yield of winter wheat was obtained at W2 N195, while the minimum at W1 N255. [Conclusion] With the increase of irrigation, negative effect of nitrogen on number of ears, number of grains per ear, 1 000-grain weight, grain yield and nitrogen accumulation decrease under lower nitrogen application rate.展开更多
This study aimed to investigate the water absorption capacity of thermally modified and non-modified spruce and blue-stained spruce wood.The wettability of wood depends on various factors,including its type,density,po...This study aimed to investigate the water absorption capacity of thermally modified and non-modified spruce and blue-stained spruce wood.The wettability of wood depends on various factors,including its type,density,porosity,and surface treatment.Wood can swell and become distorted when exposed to water or humidity,impacting its structural integrity.Hence,it is crucial to consider the water and water vapour uptake in the wood when choosing materials for applications that are likely to be exposed to moisture.Various moisture absorption tests were conducted to assess water absorption capacity,including short-term and long-term water absorption and water vapour absorption.The results showed a significant difference in the long-term exposure to water,which was related to the density of the wood.The study examined the influence of thermal treatment on the physical properties of wood and observed significant variations in mass change due to coating,indicating differences in adhesion among different wood types.Vacuum-treated blue-stained Norway spruce demonstrated higher adhesion(5%–15%)compared to air-treated samples.Furthermore,cohesion tests revealed lower cohesion force in blue-stained Norway spruce(approximately 20%–30%)compared to Norway spruce.The study also used industry-standard tests to investigate the adhesion and cohesion of nano-coatings on wood surfaces.The results provided valuable information on the properties of coatings applied to wood,which is vital in protecting and decorating wood while also providing preventive protection against wood pests,weathering,and mechanical influences.Wood modification in vacuum involves subjecting the wood to a low-pressure environment to remove air and moisture,allowing for deeper and more uniform penetration of treatment chemicals.In contrast,wood modification in air relies on the natural circulation of air to facilitate the absorption of chemical treatments,without the need for a vacuum chamber.展开更多
Sodium polyacrylate was synthesized with acrylic acid as the monomer, and sodium bisulfate and ammonium persulfate as the initiator, by means of aqueous solution polymerization. The factors influencing the properties ...Sodium polyacrylate was synthesized with acrylic acid as the monomer, and sodium bisulfate and ammonium persulfate as the initiator, by means of aqueous solution polymerization. The factors influencing the properties of moisture absorption, such as monomer concentration, dosage of initiator, and reaction temperature were systematically investigated. The experimental results indicate that the moisture-absorbing property of this polymer was better than other traditional material, such as silica gel, and molecular sieve. The best reaction condition and formula are based on the orthogonal experiment design. The optimum moisture absorbency of sodium polyacrylate reaches 1.01 g/g. The mathematical correlation of this polymer with various factors and moisture absorbency is obtained based on the multiple regression analysis. The moisture content intuitive analysis table shows that neutralization degree has the most significant influence on moisture absorbency, followed by monomer concentration and reaction temperature, while other factors have less influence.展开更多
A series of tests on physical, mechanical and chemical properties of expansive soils have shown that the standard moisture absorption water content (SMA) of expansive soils has a good linear relationship with montmori...A series of tests on physical, mechanical and chemical properties of expansive soils have shown that the standard moisture absorption water content (SMA) of expansive soils has a good linear relationship with montmorillonite content, cation exchange capacity, specific surface, and it also presents a linear relationship tendency to plastic index and free swell ratio. All this indicates that the above SMA is of clear significance in physics. The plastic index can better reflect the interaction extent between composition and dispersing character of grains, cation and clay minerals. Consequently, SMA can reflect the basic essential properties of expansive soils. On the basis of the classification results that have been published in literature and in consideration of the succession to the classification results for the free swell ratio, this paper puts forward three indexes, i.e. the SMA, plastic index and free swell ratio to classify expansive soils. The tests proposed for the classification indexes are easy to operate, simple in testing device and last a short time. Compared with the latest issued “Classification Standard Code for Rocks and Soils of Railway Projects” (TB10077-2001), the method proposed in this paper is more convenient and reasonable, and can be popularized, when environment conditions ripen, for the application in field of exploration and design of highway in the areas surrounded by expansive soils.展开更多
In the research,three kinds composite materials of biomimetic laminated boards made from cross-linking starch/maize stalk fiber-the single layer jute fiber reinforced maize stalk fiber boards,the dual layer jute fiber...In the research,three kinds composite materials of biomimetic laminated boards made from cross-linking starch/maize stalk fiber-the single layer jute fiber reinforced maize stalk fiber boards,the dual layer jute fiber reinforced maize stalk fiber boards,the jute fiber hybrid reinforced maize stalk fiber boards were obtained according to the formulation of cross-linking maize starch adhesive and the preparation process of composite materials.The hygroscopicity variation of the biomimetic laminated boards made from cross-linking starch/maize stalk fiber was investigated under different relative humidity conditions.The moisture absorption rate and the variation velocity were used as important evaluation indexes to evaluate the moisture absorption properties of the straw fiber composites.The mathematical models of the moisture absorption rate and the variation velocity were established.The hygroscopicity variation curves of three kinds of composite materials were measured under the five different relative humidity conditions.The results showed that the three kinds composites had low moisture absorption rate compared with other stalk fiber composites which were good at water resistance and the waterproof property of the three kinds stalk fibers were excellent under the experimental conditions.The research provides a useful reference to improve the water resistance of fiber composites and a new idea on the development and application of the biodegradable composites,especially the straw fiber reinforced composites.展开更多
基金Supported by National Key Research Plan Project(2016YFD0801001,2016YFD0200103,2017YFD0800500)
文摘Based on split plot design method of field test,the impacts of supplemental irrigation based on soil moisture measurement and nitrogen use on winter wheat yield and nitrogen absorption and distribution were studied.Supplemental irrigation had three levels: 60%(W_1),70%(W_2) and 80%(W3) of the targeted relative water content at 0-40 cm of soil layer during jointing period of winter wheat.Nitrogen fertilization had three levels: not using nitrogen(N_0),using pure nitrogen of 195 kg/hm^2(N_(195)) and 255 kg/hm^2(N_(255)).Results showed that:(i)different supplemental irrigation and nitrogen fertilization significantly affected plant height and leaf area of winter wheat during key growth period.Under the same supplemental irrigation treatment,both plant height and leaf area of winter wheat showed as N_(255)> N_(195)> N_0(P <0.05).Plant height in N_(195) and N_(255)treatments was significantly higher than that in N_0 treatment,but there was not significant difference between N_(195) and N_(255)(P >0.05).Under the same nitrogen fertilization,plant height in W_2(569.4 m^3/hm^2) and W3(873.45 m^3/hm^2) treatments was significant higher than that in W_1(265.2 m^3/hm^2),but there was not significant difference between W_2 and W3(P >0.05).It illustrated that excessive nitrogen fertilization and supplemental irrigation did not significantly affect plant height and leaf area of winter wheat.(ii) Under the same nitrogen fertilization level,yield increase effect of winter wheat by supplemental irrigation showed a declining trend with nitrogen application amount increased.It illustrated that nitrogen fertilization and supplemental irrigation had certain critical values on the yield of winter wheat.When surpassing the critical value,the yield declined.When nitrogen fertilization amount was 195 kg/hm^2,and supplemental irrigation amount was 70% of field moisture capacity(569.4 m^3/hm^2),the highest yield 8500 kg/hm^2 could be obtained.(iii) During mature period of winter wheat,nitrogen accumulation amount of plant treated by nitrogen was significantly higher than that not treated by nitrogen(P <0.05).But under the treatments of W_2 and W3,nitrogen accumulation amount in N_(255) significantly declined when compared with N_(195)(P <0.05).Especially under W3(873.45 m^3/hm^2) level,nitrogen accumulation amount in N_(255) was even lower than N_0.Under the treatments of N_0 and N_(195),nitrogen accumulation amount of plant significantly increased with supplemental irrigation increased(P < 0.05).But under N_(255) treatment,there was not significant difference(P > 0.05).It illustrated that moderate supplemental irrigation and nitrogen fertilization could improve nitrogen absorption ability of winter wheat,but excessive supplemental irrigation and nitrogen fertilization were not favorable for plant's nitrogen absorption.(iv) Although the increase of supplemental irrigation during jointing period improved nitrogen absorption ability of winter wheat and promoted winter wheat absorbing more nitrogen,it inhibited nitrogen transferring and distributing to seed.Comprehensively considering growth condition of winter wheat and nitrogen risk condition,it is suggested that nitrogen application amount was 195 kg/hm^2,and supplemental irrigation reached 70% of field moisture capacity(569.4 m^3/hm^2),which could be as the suitable water and fertilizer use amounts in the region.
文摘As an alternative to conventional encapsulation concepts for a double glass photovoltaic(PV)module,we introduce an innovative ionomer-based multi-layer encapsulant,by which the application of additional edge sealing to prevent moisture penetration is not required.The spontaneous moisture absorption and desorption of this encapsulant and its raw materials,poly(ethylene-co-acrylic acid)and an ionomer,are analyzed under different climatic conditions in this work.The relative air humidity is thermodynamically the driving force for these inverse processes and determines the corresponding equilibrium moisture content(EMC).Higher air humidity results in a larger EMC.The homogenization of the absorbed water molecules is a diffusion-controlled process,in which temperature plays a dominant role.Nevertheless,the diffusion coefficient at a higher temperature is still relatively low.Hence,under normal climatic conditions for the application of PV modules,we believe that the investigated ionomer-based encapsulant can“breathe”the humidity:During the day,when there is higher relative humidity,it“inhales”(absorbs)moisture and restrains it within the outer edge of the module;then at night,when there is a lower relative humidity,it“exhales”(desorbs)the moisture.In this way,the encapsulant protects the cell from moisture ingress.
文摘The Lop Nur dry salt lake,Xinjiang province,is charactered by typical physiognomy salt-crust,located in39.6-41.3N.latitude and 89.6-91.4E.longitude.The thickness of salt-crust is about from 20 cm to 100 cm,and
文摘The water vapour resistance of clothing ensembles is not as commonly determined as dry thermal insulation. The measurement techniques are more complicated and the measurement values differ among laboratories. Due to complicated moisture transfer process through clothing ensemble, the moisture absorbed and evaporated varies in transient and steady state phases depending on properties, thickness of clothing, and environmental conditions. The purpose of this study was to measure moisture gain inside hygroscopic underwear, and hydrophobic and permeable outer wear as a function of time, to investigate mass loss from ＂skin＂ as well as from the manikin, to quantify evaporative heat loss and total heat loss from the manikin, and to determine water vaponr resistance of clothing. Manikin Tore was used by wearing wet ＂skin＂ to simulate sweating condition. Moisture content in the inner garment gain shows an exponential relation against time. Moisture in the outer permeable layer shows little gain. On the contrary, mass loss directly from the wet skin decreases exponentially. The mass loss from the manikin is relatively stable throughout three test phases. The evaporative heat loss is about 2/3 of the total heat loss from the sweating manikin. While measuring the evaporative resistance of clothing ensembles with hygroscopic inner garment and permeable outer garment, unlike to measure ensembles with impermeable outer layer, one hour measurement time is enough to get relatively stable results. The variation between the 1^rt hour and the 3^nd hour is less than 5%. The length of transient period and measurement time is dependent on the permeability, thickness of clothing ensembles and environmental conditions.
文摘The paper analyses the effect of stitch geometrical modality changing after moisture absorption on the porosity of knitted fabrics,and educes the formulas between porosity and stitch parameters.Regarding as the cell stitch,the increasing of yarn diameter brings the porosity decreasing and the fabric shrinking in the wale direction.While the diameter keeps invariability,the yarn elongating brings the fabric humping up as well as the increasing porosity.The air-permeability experiments have been conducted to validate the theoretical analysis,and there is reasonable agreement between the theories and experiments.
文摘We have been studying the function and structure of fatty acid-containing extracellular polysaccharides (FACEPS) produced by bacteria belonging to the genus Rhodococcus. In this study, we examined the relationships between the structure and emulsifying, thickening, moisture-absorption, and moisture-retention capabilities of rhodococcal FACEPS using S-2 EPS produced by R. rhodochrous strain S-2. We prepared chemically deacylated S-2 EPS (DeAcyl S-2 EPS) and palmitoylated DeAcyl S-2 EPS (ReAcyl S-2 EPS), and compared them with native S-2 EPS. All of the properties were attenuated and recovered by deacylation and reacylation of S-2 EPS, respectively. These results suggest that the fatty acid moiety of rhodococcal FACEPS is involved in such functional properties. We also showed that palmitoylation improved the emulsifying, moisture-ab-sorption, and moisture-retention abilities of other acidic polysaccharides that are commercially available. These results suggest that the acidity of the polysaccharide backbone is at least partly responsible for the observed functionality of fatty acid-containing polysaccharides. To our knowledge, this is the first report on multifunctional property of an anionic polymer incorporating low amounts of hydrophobic residues. The present findings could be useful for the creation of new multifunctional surfactants from renewable raw materials for use in various industries, e.g., in cosmetics.
文摘In the accompanying paper (Part 1), we showed that the fatty acid moiety and the acidity of the polysaccharide-backbone of a fatty acid-containing polysaccharide might be involved in its emul-sification, moisture absorption, and moisture retention abilities. In this study, we synthesized alkyl esterified poly-γ-glutamic acid (PGA) with various chain lengths and degrees of substitution of the alkyl moieties to examine how hydrophobic groups incorporated in the anionic polymer contribute to enhanced emulsification, moisture absorption, and moisture retention. With a low degree of alkylation of PGA, these abilities were drastically improved. To improve the moisture absorption of PGA, alkylation with a short chain length is effective in forming interspaces between PGA chains to trap water molecules. Hydrophobic-hydrophilic balance may also be important to improve the emulsification and moisture retention abilities of PGA alkylates. To the best of our knowledge, this is the first report of the relationship between the structure and the multifunctional abilities of an anionic polymer incorporated with a small amount of hydrophobic residue. PGA alkylates, as well as fatty acid-containing polysaccharides, have potential use as multifunctional surfactants throughout various industries.
基金Supported by National Nature Science Fund ( No.50643014)"Yangtze Scholar and Innovation Team Development Plan"Innovation Team(No.IRT0654)Science Research Fund of Zhejiang Sci-Tech University (No.0601065-Y)
文摘An important property of moisture absorption and sweat discharge yarns is their water transport property. In the paper, two water transport models of moisture absorption and sweat discharge yarns were developed to investigate the influence factors on their wicking rate. In parallel Column Pores Model, wicking rate is determined by the equivalent capillary radius R and length of the capillary tube L. In Pellets Accumulation Model, wicking rate is decided by the capillary radius r and length of the fiber unit assemble L0.
基金The author would like to acknowledge the Fuzhou University for providing the start-up research funding for Minjiang Scholar Distinguished Professor scheme in Fujian Province,China.Financial support from the National Natural Science Foundation of China(52005108)is also appreciated.
文摘Composite materials are lightweight structures and have been wildly used in marine applications.A carbon composite structure usually absorbs moisture while in-service,which can significantly affect its properties,and detriments the overall performance.We perform a detailed study on moisture absorption and diffusion of a carbon fibre reinforced vinyl ester resin composite system.Composite samples are immersed directly in four different solutions at a temperature of 37±0.5℃for 1444h.The moisture diffusion is analysed through the Fickian diffusion model;the diffusion parameters are subsequently determined from the gravimetric data.The moisture absorption and interaction with the composite constituents are then discussed.These indicate the fundamentals of the moisture absorption and diffusion within the carbon composite structure.
基金Supported by the Water-and Fertilizer-saving Technology Demonstration for Wheat and Maize in Central Henan Province(2013BAD07B07-2)National Key Technology Research and Development Program during the 12th Five-year Plan Period(2012BAD04B07-2)~~
文摘[Objective] This study aimed to determine the effects of supplemental irrigation on yield and nitrogen uptake in winter wheat. [Method] Three supplemental irrigation levels were set based on the target soil contents of 60%, 70% and 80%） at jointing stage of wheat. Moreover, three nitrogen levels （0, 195 and 255 kg/hm^2） were designed. The experimental plots were arranged fol owing a split-plot design. Zhoumai 18 was selected as the experimental material. [Result] Supplemental irrigation and nitrogen application in combination had significant or extremely significant effects on yield, yield components and nitrogen uptake in winter wheat. The interaction between irrigation and nitrogen fertilization had significant or extremely significant influence on the number of ears, number of grains per ear, 1 000-grain weight, grain yield and nitrogen accumulation in winter wheat. Under different combinations of supplemental irrigation and nitrogen application, the maximum yield of winter wheat was obtained at W2 N195, while the minimum at W1 N255. [Conclusion] With the increase of irrigation, negative effect of nitrogen on number of ears, number of grains per ear, 1 000-grain weight, grain yield and nitrogen accumulation decrease under lower nitrogen application rate.
文摘This study aimed to investigate the water absorption capacity of thermally modified and non-modified spruce and blue-stained spruce wood.The wettability of wood depends on various factors,including its type,density,porosity,and surface treatment.Wood can swell and become distorted when exposed to water or humidity,impacting its structural integrity.Hence,it is crucial to consider the water and water vapour uptake in the wood when choosing materials for applications that are likely to be exposed to moisture.Various moisture absorption tests were conducted to assess water absorption capacity,including short-term and long-term water absorption and water vapour absorption.The results showed a significant difference in the long-term exposure to water,which was related to the density of the wood.The study examined the influence of thermal treatment on the physical properties of wood and observed significant variations in mass change due to coating,indicating differences in adhesion among different wood types.Vacuum-treated blue-stained Norway spruce demonstrated higher adhesion(5%–15%)compared to air-treated samples.Furthermore,cohesion tests revealed lower cohesion force in blue-stained Norway spruce(approximately 20%–30%)compared to Norway spruce.The study also used industry-standard tests to investigate the adhesion and cohesion of nano-coatings on wood surfaces.The results provided valuable information on the properties of coatings applied to wood,which is vital in protecting and decorating wood while also providing preventive protection against wood pests,weathering,and mechanical influences.Wood modification in vacuum involves subjecting the wood to a low-pressure environment to remove air and moisture,allowing for deeper and more uniform penetration of treatment chemicals.In contrast,wood modification in air relies on the natural circulation of air to facilitate the absorption of chemical treatments,without the need for a vacuum chamber.
基金Supported by the 863 Project (Grant No. 2005AA001650)
文摘Sodium polyacrylate was synthesized with acrylic acid as the monomer, and sodium bisulfate and ammonium persulfate as the initiator, by means of aqueous solution polymerization. The factors influencing the properties of moisture absorption, such as monomer concentration, dosage of initiator, and reaction temperature were systematically investigated. The experimental results indicate that the moisture-absorbing property of this polymer was better than other traditional material, such as silica gel, and molecular sieve. The best reaction condition and formula are based on the orthogonal experiment design. The optimum moisture absorbency of sodium polyacrylate reaches 1.01 g/g. The mathematical correlation of this polymer with various factors and moisture absorbency is obtained based on the multiple regression analysis. The moisture content intuitive analysis table shows that neutralization degree has the most significant influence on moisture absorbency, followed by monomer concentration and reaction temperature, while other factors have less influence.
文摘A series of tests on physical, mechanical and chemical properties of expansive soils have shown that the standard moisture absorption water content (SMA) of expansive soils has a good linear relationship with montmorillonite content, cation exchange capacity, specific surface, and it also presents a linear relationship tendency to plastic index and free swell ratio. All this indicates that the above SMA is of clear significance in physics. The plastic index can better reflect the interaction extent between composition and dispersing character of grains, cation and clay minerals. Consequently, SMA can reflect the basic essential properties of expansive soils. On the basis of the classification results that have been published in literature and in consideration of the succession to the classification results for the free swell ratio, this paper puts forward three indexes, i.e. the SMA, plastic index and free swell ratio to classify expansive soils. The tests proposed for the classification indexes are easy to operate, simple in testing device and last a short time. Compared with the latest issued “Classification Standard Code for Rocks and Soils of Railway Projects” (TB10077-2001), the method proposed in this paper is more convenient and reasonable, and can be popularized, when environment conditions ripen, for the application in field of exploration and design of highway in the areas surrounded by expansive soils.
基金supported by National Science Fund for Distinguished Young Scho lars of China(Grant No.50025516)National Natural Science Foundation of China(Grant No.50675087,50673037,5030600131)+1 种基金"985 Project"of Jilin University,Natural Science Foundation of Henan Educational Committee(Grant No.2009B210006)Innovation Ability Foundation of Natural Science(Grant No.2013ZCX002)of Henan University of Science and Technology.
文摘In the research,three kinds composite materials of biomimetic laminated boards made from cross-linking starch/maize stalk fiber-the single layer jute fiber reinforced maize stalk fiber boards,the dual layer jute fiber reinforced maize stalk fiber boards,the jute fiber hybrid reinforced maize stalk fiber boards were obtained according to the formulation of cross-linking maize starch adhesive and the preparation process of composite materials.The hygroscopicity variation of the biomimetic laminated boards made from cross-linking starch/maize stalk fiber was investigated under different relative humidity conditions.The moisture absorption rate and the variation velocity were used as important evaluation indexes to evaluate the moisture absorption properties of the straw fiber composites.The mathematical models of the moisture absorption rate and the variation velocity were established.The hygroscopicity variation curves of three kinds of composite materials were measured under the five different relative humidity conditions.The results showed that the three kinds composites had low moisture absorption rate compared with other stalk fiber composites which were good at water resistance and the waterproof property of the three kinds stalk fibers were excellent under the experimental conditions.The research provides a useful reference to improve the water resistance of fiber composites and a new idea on the development and application of the biodegradable composites,especially the straw fiber reinforced composites.
