Lumber moisture content(LMC) is the important parameter to judge the dryness of lumber and the quality of wooden products.Nevertheless the data acquired are mostly redundant and incomplete because of the complexity of...Lumber moisture content(LMC) is the important parameter to judge the dryness of lumber and the quality of wooden products.Nevertheless the data acquired are mostly redundant and incomplete because of the complexity of the course of drying,by interference factors that exist in the dryness environment and by the physical characteristics of the lumber itself.To improve the measuring accuracy and reliability of LMC,the optimal support vector machine(SVM) algorithm was put forward for regression analysis LMC.Environmental factors such as air temperature and relative humidity were considered,the data of which were extracted with the principle component analysis method.The regression and prediction of SVM was optimized based on the grid search(GS) technique.Groups of data were sampled and analyzed,and simulation comparison of forecasting performance shows that the main component data were extracted to speed up the convergence rate of the optimum algorithm.The GS-SVM shows a better performance in solving the LMC measuring and forecasting problem.展开更多
Photochromic wood was fabricated by coating microencapsulated photochromic material(MP)/polydimethylsiloxane composites onto wood using a simple drop-coating method.Urea-melamine–formaldehyde resin was used to microe...Photochromic wood was fabricated by coating microencapsulated photochromic material(MP)/polydimethylsiloxane composites onto wood using a simple drop-coating method.Urea-melamine–formaldehyde resin was used to microencapsulate the photochromic material(PM)via in situ polymerization.The concentration of the MP affected the photochromic property of the wood surface.The total color change(ΔE*)reached 82.2 when the concentration of the composite coating is 8%.Adhesion tests confirmed that the composite coating adhered firmly to the wood.This method is potentially useful for the production of functional wooden products,such as anti-counterfeiting materials and aesthetic wood.展开更多
Volume variation is an uncertainty element which affects timber processing. We studied the volume variation of logs caused by quality defects in traditional timber processing and set up an optimization approach,using ...Volume variation is an uncertainty element which affects timber processing. We studied the volume variation of logs caused by quality defects in traditional timber processing and set up an optimization approach,using a robust optimization method. We used total number of acceptable boards produced to study the relationship between board thickness and raw material logs, using a heuristic search algorithm to control the variation of board volume to improve the output of boards, reduce the quantity of by-products, and lower production costs. The robust optimization method can effectively control the impact of volume variations in timber processing, reduce cutting waste as far as possible using incremental processing and increase profits, maximize the utilization ratio of timber, prevent waste in processing, cultivate the productive type of tree species and save forest resources.展开更多
Phosphorus-containing compounds are considered as the potential alternatives of traditional inhibitors for suppressing the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs),but the suppression ...Phosphorus-containing compounds are considered as the potential alternatives of traditional inhibitors for suppressing the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs),but the suppression characteristics are scarcely studied.In this study,ammonium dihydrogen phosphate(ADP)was selected as the inhibitor to inhibit the PCDD/F formation via de novo synthesis at 350℃.The influence of oxygen content and addition method on PCDD/F inhibition was systematically investigated by means of statistical analysis and morphological characterization.The results showed that oxygen enhanced the formation of PCDD/Fs from 1470 ng g^(−1)(9.78 ng I-TEQ g^(−1))to 2110 ng g^(−1)(14.8 ng I-TEQ g^(−1)).ADP significantly inhibited the PCDD/F formation,with inhibition efficiencies ranging from 82.0%to 97.7%.Herein,a higher oxygen content and the premixed way intensified the suppression effect.Dibenzo-p-dioxin(DD)/dibenzofuran(DF)chlorination was proven to be effectively suppressed while chlorophenol(CP)route was not obviously influenced.With the addition of ADP,Cl source was significantly reduced and the formation of organic Cl was effectively inhibited.Also,it decreased the proportion of C–O/C=N and C=O,revealing the efficient inhibition of carbon oxidation.Meanwhile,the formation of copper phosphate and copper pyrophosphate was observed in XPS(X-ray photoelectron spectroscopy)spectra,indicating that the catalytic metal Cu was chelated and passivated by ADP.The premixed way had a better effect on reducing Cl resources,inhibiting oxidation and chelating metals,due to the direct contact with inhibitor.However,the separation method could only depend on the decomposed gases,resulting in a lower inhibition efficiency.展开更多
Due to the various pH liquid environment in nature,the pH-responsive lubricating hydrogel is widely investigated and developed for tissue interface substitute.However,the applied liquid environment will lead to poor m...Due to the various pH liquid environment in nature,the pH-responsive lubricating hydrogel is widely investigated and developed for tissue interface substitute.However,the applied liquid environment will lead to poor mechanical property and weaken the pH-responsive capability.In this work,a carbon dotsenhanced pH-responsive lubricating hydrogel is developed by combining a pH-responsive section of dynamic PVA-borax network into a PAAm covalent polymer network.The formed hydrogel presents a partial gel-sol transition under controlled pH environments.At low pH environments(<6.0),the formed lubricating layer originated from dynamic disassembly of PVA-borax hydrogel,and brings the lubricating properties on the hydrogel surface.Moreover,the mechanical strength and lubrication properties are well promoted by introducing the carbon dots into the hydrogel,the blue sol layer can be observed more visually under the fluorescence microscope.The pH-response also exhibits well reversibility.The prepared hydrogel broadens the idea for designing pH-responsive soft materials for soft lubricating actuator or robot.展开更多
Cartilage-inspired hydrogel has attracted great interest due to its tunable mechanics and low friction.However,it is incapable of self-healing under a complex dynamic shearing environment.In this work,a self-healing s...Cartilage-inspired hydrogel has attracted great interest due to its tunable mechanics and low friction.However,it is incapable of self-healing under a complex dynamic shearing environment.In this work,a self-healing semi-convertible hydrogel(SHSCH)is developed,which can recover its unique active lubricating function under shearing.Based on the cooperating strategy of noncovalent and covalent bonding,the SHSCH is composed of three interpenetrated networks including:(1)shearresponsive N-fluorenylmethoxycarbonyl-L-tryptophan(FT)supramolecular network,(2)self-healing polyhydroxyethyl acrylamide(PHEAA)network,and(3)rigid polyvinyl alcohol(PVA)covalent network.The shearresponsive lubricating function and mechanical property can be self-healed under a shearing environment through the noncovalent hydrogen-bonding assembly of PHEAA associated by theπ–πassembly of FT.The asdeveloped SCH provides a self-healing model comparable with traditional self-healing lubricating materials through encapsulating lubricant microcapsules or infusing lubricants onto surfaces.We demonstrated a proofof-concept of the self-healing lubrication of a simplified artificial worn cartilage model under a dynamic shearing condition.This study will offer a potential strategy on designing the self-healing soft devices under dynamic stimuli far beyond the lubricating materials.展开更多
Although bone morphogenetic protein(BMP) and WNT signaling play pivotal roles in bone development,homeostasis, and regeneration, the applications of proteins to stimulate corresponding signaling pathways showed limite...Although bone morphogenetic protein(BMP) and WNT signaling play pivotal roles in bone development,homeostasis, and regeneration, the applications of proteins to stimulate corresponding signaling pathways showed limited outcomes in the repair and regeneration of bone defects that might be attributed to the reciprocal interventions of these pathways. In order to satisfy the combinational and sequential activation of BMP and WNT pathways, inspired by the heterogeneous hydrogel-liked structures of Brasenia, heterogeneous alginate/chitosan hydrogels were fabricated and spatially loaded with FK506 and BIO to achieve sustained and sequential release of the activators. Alkaline phosphatase staining, alizarin red staining and q RT-PCR results suggested that FK506 and BIO enhanced osteoblastic differentiation in vitro when used separately. Besides, by mixing and matching the activators and the hydrogel layers, a superior releasing mode that a combination of early FK506 release and following BIO release was identified via both in vitro and in vivo explorations for most efficient bone regeneration. These results suggested that drug-loaded heterogeneous hydrogels possess great potentials in treating bone loss defects for future clinical practice.展开更多
In this paper, a novel Krein space approach to robust estimation for uncertain systems with accumulated bias is proposed. The bias is impacted by system uncertainties and exists in both state transition and observer m...In this paper, a novel Krein space approach to robust estimation for uncertain systems with accumulated bias is proposed. The bias is impacted by system uncertainties and exists in both state transition and observer matrices. Initial conditions and cross-correlated uncertainty inputs are described by the sum quadratic constraint （SQC）. Without modifying the SQC, the minimal state of the SQC is obtained through Krein space method. The inertia condition for a minimum of a deterministic quadratic form is derived when the coefficient of observer uncertainty input is non-unit matrix. Recursions of Krein space state filtering and bias filtering are developed respectively. Since the cross correlation between uncertainties is considered, a cross correlation gain is introduced into the posteriori estimator. Finally, a numerical example illustrates the performance of the proposed filter.展开更多
基金supported by the Natural Science Foundation of China(Grant No.31470715),(Grant No.31470714)the Fundamental Research Funds for the Central Universities(2572016EBT1)
文摘Lumber moisture content(LMC) is the important parameter to judge the dryness of lumber and the quality of wooden products.Nevertheless the data acquired are mostly redundant and incomplete because of the complexity of the course of drying,by interference factors that exist in the dryness environment and by the physical characteristics of the lumber itself.To improve the measuring accuracy and reliability of LMC,the optimal support vector machine(SVM) algorithm was put forward for regression analysis LMC.Environmental factors such as air temperature and relative humidity were considered,the data of which were extracted with the principle component analysis method.The regression and prediction of SVM was optimized based on the grid search(GS) technique.Groups of data were sampled and analyzed,and simulation comparison of forecasting performance shows that the main component data were extracted to speed up the convergence rate of the optimum algorithm.The GS-SVM shows a better performance in solving the LMC measuring and forecasting problem.
基金financially supported by the National Natural Science Foundation Youth Fund of China(31800489)the Special Fund for Research on Scientific and Technological Innovation Talents in Harbin(2017RAQXJ092)+1 种基金Natural Science Foundation of Heilongjiang Province of China(LH2019E070)Postdoctoral Science Foundation funded project of Heilongjiang Province of China(LBH Z16007)。
文摘Photochromic wood was fabricated by coating microencapsulated photochromic material(MP)/polydimethylsiloxane composites onto wood using a simple drop-coating method.Urea-melamine–formaldehyde resin was used to microencapsulate the photochromic material(PM)via in situ polymerization.The concentration of the MP affected the photochromic property of the wood surface.The total color change(ΔE*)reached 82.2 when the concentration of the composite coating is 8%.Adhesion tests confirmed that the composite coating adhered firmly to the wood.This method is potentially useful for the production of functional wooden products,such as anti-counterfeiting materials and aesthetic wood.
基金supported by the Fundamental Research Funds for the Central Universities(Project No.2572015CB06)Nature Science Foundation of Heilongjiang Province(LC201407)
文摘Volume variation is an uncertainty element which affects timber processing. We studied the volume variation of logs caused by quality defects in traditional timber processing and set up an optimization approach,using a robust optimization method. We used total number of acceptable boards produced to study the relationship between board thickness and raw material logs, using a heuristic search algorithm to control the variation of board volume to improve the output of boards, reduce the quantity of by-products, and lower production costs. The robust optimization method can effectively control the impact of volume variations in timber processing, reduce cutting waste as far as possible using incremental processing and increase profits, maximize the utilization ratio of timber, prevent waste in processing, cultivate the productive type of tree species and save forest resources.
基金supported by the Fundamental Research Funds for the Central Universities(No.K20220145).
文摘Phosphorus-containing compounds are considered as the potential alternatives of traditional inhibitors for suppressing the formation of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs),but the suppression characteristics are scarcely studied.In this study,ammonium dihydrogen phosphate(ADP)was selected as the inhibitor to inhibit the PCDD/F formation via de novo synthesis at 350℃.The influence of oxygen content and addition method on PCDD/F inhibition was systematically investigated by means of statistical analysis and morphological characterization.The results showed that oxygen enhanced the formation of PCDD/Fs from 1470 ng g^(−1)(9.78 ng I-TEQ g^(−1))to 2110 ng g^(−1)(14.8 ng I-TEQ g^(−1)).ADP significantly inhibited the PCDD/F formation,with inhibition efficiencies ranging from 82.0%to 97.7%.Herein,a higher oxygen content and the premixed way intensified the suppression effect.Dibenzo-p-dioxin(DD)/dibenzofuran(DF)chlorination was proven to be effectively suppressed while chlorophenol(CP)route was not obviously influenced.With the addition of ADP,Cl source was significantly reduced and the formation of organic Cl was effectively inhibited.Also,it decreased the proportion of C–O/C=N and C=O,revealing the efficient inhibition of carbon oxidation.Meanwhile,the formation of copper phosphate and copper pyrophosphate was observed in XPS(X-ray photoelectron spectroscopy)spectra,indicating that the catalytic metal Cu was chelated and passivated by ADP.The premixed way had a better effect on reducing Cl resources,inhibiting oxidation and chelating metals,due to the direct contact with inhibitor.However,the separation method could only depend on the decomposed gases,resulting in a lower inhibition efficiency.
基金supported by the National Natural Science Foundation of China(No.22175075).
文摘Due to the various pH liquid environment in nature,the pH-responsive lubricating hydrogel is widely investigated and developed for tissue interface substitute.However,the applied liquid environment will lead to poor mechanical property and weaken the pH-responsive capability.In this work,a carbon dotsenhanced pH-responsive lubricating hydrogel is developed by combining a pH-responsive section of dynamic PVA-borax network into a PAAm covalent polymer network.The formed hydrogel presents a partial gel-sol transition under controlled pH environments.At low pH environments(<6.0),the formed lubricating layer originated from dynamic disassembly of PVA-borax hydrogel,and brings the lubricating properties on the hydrogel surface.Moreover,the mechanical strength and lubrication properties are well promoted by introducing the carbon dots into the hydrogel,the blue sol layer can be observed more visually under the fluorescence microscope.The pH-response also exhibits well reversibility.The prepared hydrogel broadens the idea for designing pH-responsive soft materials for soft lubricating actuator or robot.
基金supported financially by the National Natural Science Foundation of China(grant nos.22175075,22035008,21972155,21774044,21425314,21434009,21421061).
文摘Cartilage-inspired hydrogel has attracted great interest due to its tunable mechanics and low friction.However,it is incapable of self-healing under a complex dynamic shearing environment.In this work,a self-healing semi-convertible hydrogel(SHSCH)is developed,which can recover its unique active lubricating function under shearing.Based on the cooperating strategy of noncovalent and covalent bonding,the SHSCH is composed of three interpenetrated networks including:(1)shearresponsive N-fluorenylmethoxycarbonyl-L-tryptophan(FT)supramolecular network,(2)self-healing polyhydroxyethyl acrylamide(PHEAA)network,and(3)rigid polyvinyl alcohol(PVA)covalent network.The shearresponsive lubricating function and mechanical property can be self-healed under a shearing environment through the noncovalent hydrogen-bonding assembly of PHEAA associated by theπ–πassembly of FT.The asdeveloped SCH provides a self-healing model comparable with traditional self-healing lubricating materials through encapsulating lubricant microcapsules or infusing lubricants onto surfaces.We demonstrated a proofof-concept of the self-healing lubrication of a simplified artificial worn cartilage model under a dynamic shearing condition.This study will offer a potential strategy on designing the self-healing soft devices under dynamic stimuli far beyond the lubricating materials.
基金supported by the National Natural Science Foundation of China (Nos. 81970903 and 81920108012)Fundamental Research Funds for the Central Universities,Jilin Provincial Science & Technology Department (No. 20200201527JC)+1 种基金Jilin Department of Health (No. 2019Q013)Department of Finance of Jilin Province (No. JCSZ2019378-6)。
文摘Although bone morphogenetic protein(BMP) and WNT signaling play pivotal roles in bone development,homeostasis, and regeneration, the applications of proteins to stimulate corresponding signaling pathways showed limited outcomes in the repair and regeneration of bone defects that might be attributed to the reciprocal interventions of these pathways. In order to satisfy the combinational and sequential activation of BMP and WNT pathways, inspired by the heterogeneous hydrogel-liked structures of Brasenia, heterogeneous alginate/chitosan hydrogels were fabricated and spatially loaded with FK506 and BIO to achieve sustained and sequential release of the activators. Alkaline phosphatase staining, alizarin red staining and q RT-PCR results suggested that FK506 and BIO enhanced osteoblastic differentiation in vitro when used separately. Besides, by mixing and matching the activators and the hydrogel layers, a superior releasing mode that a combination of early FK506 release and following BIO release was identified via both in vitro and in vivo explorations for most efficient bone regeneration. These results suggested that drug-loaded heterogeneous hydrogels possess great potentials in treating bone loss defects for future clinical practice.
基金financially supported by the National Natural Science Foundation of China (21774044, 21425314, 21434009 and 21421061)Ministry of Science and Technology (2013YQ190467)the Top-Notch Young Talents Program of China
基金supported by the Fundamental Research Funds for the Central Universities(No.DL13BB14)
文摘In this paper, a novel Krein space approach to robust estimation for uncertain systems with accumulated bias is proposed. The bias is impacted by system uncertainties and exists in both state transition and observer matrices. Initial conditions and cross-correlated uncertainty inputs are described by the sum quadratic constraint （SQC）. Without modifying the SQC, the minimal state of the SQC is obtained through Krein space method. The inertia condition for a minimum of a deterministic quadratic form is derived when the coefficient of observer uncertainty input is non-unit matrix. Recursions of Krein space state filtering and bias filtering are developed respectively. Since the cross correlation between uncertainties is considered, a cross correlation gain is introduced into the posteriori estimator. Finally, a numerical example illustrates the performance of the proposed filter.
