With the rapid development of wireless communications systems,different system standards are being merged.Operators take stringent measures to reduce Operational Expenditure(OPEX)and Capital Expenditure(CAPEX);and as ...With the rapid development of wireless communications systems,different system standards are being merged.Operators take stringent measures to reduce Operational Expenditure(OPEX)and Capital Expenditure(CAPEX);and as a result,soft base stations supporting multiple standards become the evolutionary tend of wireless base stations.This paper introduces the background of soft base stations and analyzes their architecture design,system modules.The key technologies in system implementation and future directions are also presented.展开更多
Mar and abrasion resistance were investigated by a progressive load scratch test and steel wool abrasion test, respectively. Two acrylic coating systems including trimethylolpropane triacrylate (TMPTA) and pentaerythr...Mar and abrasion resistance were investigated by a progressive load scratch test and steel wool abrasion test, respectively. Two acrylic coating systems including trimethylolpropane triacrylate (TMPTA) and pentaerythritol triacrylate (PETA) were prepared. A soft base layer was introduced as an intermediate layer between two different types of top layer and poly (methyl methacrylate) (PMMA) substrate to demonstrate the effect of soft base layer on mar and abrasion resistance. Abrasion damage on the coating surface was found to be less severe, when the soft base layer was incorporated into the coating systems. The reduction in scratch coefficient of friction (SCOF) and surface roughness was also observed. The results suggested that mar and abrasion resistance was greatly influenced by the presence of soft base layer, although different top layers were used. Moreover, it was found that abrasion resistance was further improved as the thicker soft base layer was applied.展开更多
This paper proposes a soft direct-adaptation based bidirectional turbo equalizer for multiple-input multiple-output underwater acoustic communication systems. Soft, rather than hard, direct-adaptation based equalizer ...This paper proposes a soft direct-adaptation based bidirectional turbo equalizer for multiple-input multiple-output underwater acoustic communication systems. Soft, rather than hard, direct-adaptation based equalizer combined with the fast self-optimized least mean square algorithm is employed to achieve a faster convergence rate, and the second-order phase-locked loop is embedded into the equalizer to track the time-varying channel. Meanwhile, by utilizing a weighted linear combining scheme, the conventional soft direct-adaptation based equalizer is combined with the time-reversed soft direct-adaptation based equalizer to exploit bidirectional diversity and mitigate error propagation. Both the simulation and experimental results demonstrate that the soft direct-adaptation based bidirectional turbo equalizer outperforms the single-direction soft direct-adaptation based turbo equalizer, and achieves a faster convergence rate than the hard direct-adaptation based bidirectional turbo equalizer.展开更多
Matrix completion is the extension of compressed sensing.In compressed sensing,we solve the underdetermined equations using sparsity prior of the unknown signals.However,in matrix completion,we solve the underdetermin...Matrix completion is the extension of compressed sensing.In compressed sensing,we solve the underdetermined equations using sparsity prior of the unknown signals.However,in matrix completion,we solve the underdetermined equations based on sparsity prior in singular values set of the unknown matrix,which also calls low-rank prior of the unknown matrix.This paper firstly introduces basic concept of matrix completion,analyses the matrix suitably used in matrix completion,and shows that such matrix should satisfy two conditions:low rank and incoherence property.Then the paper provides three reconstruction algorithms commonly used in matrix completion:singular value thresholding algorithm,singular value projection,and atomic decomposition for minimum rank approximation,puts forward their shortcoming to know the rank of original matrix.The Projected Gradient Descent based on Soft Thresholding(STPGD),proposed in this paper predicts the rank of unknown matrix using soft thresholding,and iteratives based on projected gradient descent,thus it could estimate the rank of unknown matrix exactly with low computational complexity,this is verified by numerical experiments.We also analyze the convergence and computational complexity of the STPGD algorithm,point out this algorithm is guaranteed to converge,and analyse the number of iterations needed to reach reconstruction error.Compared the computational complexity of the STPGD algorithm to other algorithms,we draw the conclusion that the STPGD algorithm not only reduces the computational complexity,but also improves the precision of the reconstruction solution.展开更多
Microstructures and magnetic properties of Fe84Nb7B9,Fe80Ti8B 12 and Fe32Ni36（Nb/V）7Si8B17 powders and their bulk alloys prepared by mechanical alloying（MA） method and hot-press sintering were studied. The results...Microstructures and magnetic properties of Fe84Nb7B9,Fe80Ti8B 12 and Fe32Ni36（Nb/V）7Si8B17 powders and their bulk alloys prepared by mechanical alloying（MA） method and hot-press sintering were studied. The results show that: 1) After MA for 20 h,nanocrystalline bcc singl e phase supersaturated solid solution forms in Fe84-Nb7B9 and Fe8 0Ti8B12 alloys,amorphous structure forms in Fe32Ni36Nb7 Si8B17 alloy,duplex microstructure composed of nanocrystalline γ- （FeNi） supersaturated solid solution and trace content of Fe2B phase forms in Fe32Ni36-V7Si8B17 alloy. 2) The decomposition process of supersaturated solid solution phases in Fe84Nb7B9 and Fe80Ti8B 12 alloys happens at 710780 ℃,crystallization reaction in Fe （32）Ni36Nb7Si8B17 alloy happens at 530 ℃（the temperature of peak value） and residual amorphous crystallized further happens at 760 ℃ （the temperature of peak value）,phase decomposition process of supersaturated solid solution at 780 ℃ （the temperature of peak value） and crystallization reaction at 431 ℃ （the temperature of peak value） happens in Fe32Ni36V7S i8B17 alloy. 3) under 900 ℃,30 MPa,（0.5 h） hot-press sintering conditions,bulk alloys with high relative density（94.7%95.8%） can be ob tained. Except that the grain size of Fe84Nb7B9 bulk alloy is large,s uperfine grains （grain size 50200 nm） are obtained in other alloys. Exc ept that single phase microstructure is obtained in Fe80Ti8B12 bul k alloy,multi-phase microstructures are obtained in other alloys. 4) The magne tic properties of Fe80Ti8B12bulk alloy（Bs=1.74 T,Hc= 4.35 kA/m） are significantly superior to those of other bulk alloys,which is r elated to the different phases of nanocrystalline or amorphous powder formed dur ing hot-press sintering process and grain size.展开更多
When a film of soft matter solutions is being dried, a skin layer often forms at its surface, which is a gel-like elastic phase made of concentrated soft matter solutions. We study the dynamics of this process by usin...When a film of soft matter solutions is being dried, a skin layer often forms at its surface, which is a gel-like elastic phase made of concentrated soft matter solutions. We study the dynamics of this process by using the solute based Lagrangian scheme which was proposed by us recently. In this scheme, the process of the gelation（i.e., the change from sol to gel） can be naturally incorporated in the diffusion equation. Effects of the elasticity of the skin phase, the evaporation rate of the solvents, and the initial concentration of the solutions are discussed. Moreover, the condition for the skin formation is provided.展开更多
Covering-based rough sets process data organized by a covering of the universe. A soft set is a parameterized family of subsets of the universe. Both theories can deal with the uncertainties of data. Soft sets have no...Covering-based rough sets process data organized by a covering of the universe. A soft set is a parameterized family of subsets of the universe. Both theories can deal with the uncertainties of data. Soft sets have not any restrictions on the approximate description of the object,and they might form a covering of the universe. From this viewpoint,we establish a connection between these two theories. Specifically,we propose a complementary parameter for this purpose. With this parameter,the soft covering approximation space is established and the two theories are bridged. Furthermore,we study some relations between the covering and the soft covering approximation space and obtain some significant results. Finally,we define a notion of combine parameter which can help us to simplify the set of parameters and reduce the storage requirement of a soft covering approximation space.展开更多
Objective To investigate a simple, valuable new method for coverage of the soft tissue defect over the lower one-third of the leg, ankle and the foot. Methods The distally based peroneus brevis muscle fkps were applie...Objective To investigate a simple, valuable new method for coverage of the soft tissue defect over the lower one-third of the leg, ankle and the foot. Methods The distally based peroneus brevis muscle fkps were applied for coverage of the soft tissue defects over the lower one-third of the leg,the ankle and the foot. The muscle flaps were covered with split-thickness skin grafts. Results The distally based peroneus brevis muscle flaps were applied for coverage of the soft tissue defects over the lower one-third of the leg, the ankle and the foot in 16 cases. The larges area of the soft tissue defect was 5 cm × 7 cm. The smallest was 3 cm × 4 cm. Primary healing occured in 14 cases undergoing muscle flap construction, second-stage healing occured in 2 cases, no total flap necrosis occured in any cases. Conclusion ThisChina Medical Abstracts(Surgery) technigue is a simple and complication are lesser. The successful rates are higher. This muscle flap is suitable to the mudium or small soft tissue展开更多
Co_(3)O_(4) is a promising catalyst for the chlorine evolution reaction(CER)in seawater;however,its CER selectivity is compromised by the adsorption of the competitive oxygen evolution reaction intermediate(OH^(-))at ...Co_(3)O_(4) is a promising catalyst for the chlorine evolution reaction(CER)in seawater;however,its CER selectivity is compromised by the adsorption of the competitive oxygen evolution reaction intermediate(OH^(-))at Co sites.Inspired by the hard-soft acid-base(HSAB)theory,this study proposes incorporating early transition metal sites(V)with a low degree of electron delocalization into Co_(3)O_(4) to modulate the selective adsorption of reactants on catalytic sites.Experimental and theoretical calculations reveal that V incorporation facilitates the electron accumulation at the Co site,significantly strengthening the interaction between Co and Cl^(-).Meanwhile,the loss of electrons from V sites generates a more localized electronic state that preferentially adsorbs OH^(-),thus reducing the Co-OH interaction and releasing more Co sites for Cl^(-)adsorption.Therefore,Co_(2)VO_(4) exhibits a high CER selectivity of 92.3%and maintains one of the highest stabilities over 300 h in natural seawater.The resulting half-flow cell achieves~100%disinfection efficiency in seawater,validating the HSAB theory-based design strategy and offering new guidance for developing highly selective seawater CER catalysts.展开更多
Catalysts CuOx/γ,-Al2O3-IH and CuOx/γ/-Al2O3-IM were prepared, characterized, and tested for styrene combustion in the absence and presence of water vapor. The effect of copper valence of the catalysts on the cataly...Catalysts CuOx/γ,-Al2O3-IH and CuOx/γ/-Al2O3-IM were prepared, characterized, and tested for styrene combustion in the absence and presence of water vapor. The effect of copper valence of the catalysts on the catalytic activity for styrene combustion was discussed using the theory of hard soft acids and bases （HSAB）. The results showed that the existence of water vapor in feed stream inhibited the catalytic activity for styrene combustion due to the competition adsorption of water molecule. HSAB theory confirmed that the local soft acidity of the catalyst CuOx/^-AI203-1H was much stronger than that of the catalyst CuOx/^-AI203-1M because of the higher content of soft acid Cu＋ on its surface, which increased the adsorption ability toward soft base of styrene and reduced the adsorption toward hard base of water vapor, and thus increased the catalytic activity for styrene combustion and weakened the negative influence of water vapor.展开更多
文摘With the rapid development of wireless communications systems,different system standards are being merged.Operators take stringent measures to reduce Operational Expenditure(OPEX)and Capital Expenditure(CAPEX);and as a result,soft base stations supporting multiple standards become the evolutionary tend of wireless base stations.This paper introduces the background of soft base stations and analyzes their architecture design,system modules.The key technologies in system implementation and future directions are also presented.
文摘Mar and abrasion resistance were investigated by a progressive load scratch test and steel wool abrasion test, respectively. Two acrylic coating systems including trimethylolpropane triacrylate (TMPTA) and pentaerythritol triacrylate (PETA) were prepared. A soft base layer was introduced as an intermediate layer between two different types of top layer and poly (methyl methacrylate) (PMMA) substrate to demonstrate the effect of soft base layer on mar and abrasion resistance. Abrasion damage on the coating surface was found to be less severe, when the soft base layer was incorporated into the coating systems. The reduction in scratch coefficient of friction (SCOF) and surface roughness was also observed. The results suggested that mar and abrasion resistance was greatly influenced by the presence of soft base layer, although different top layers were used. Moreover, it was found that abrasion resistance was further improved as the thicker soft base layer was applied.
基金the Key Project "Theory and technologies of data acquisition and reliable transmission for mobile underwater sensor node" supported by National Natural Science Foundation of China (No. 61431020)
文摘This paper proposes a soft direct-adaptation based bidirectional turbo equalizer for multiple-input multiple-output underwater acoustic communication systems. Soft, rather than hard, direct-adaptation based equalizer combined with the fast self-optimized least mean square algorithm is employed to achieve a faster convergence rate, and the second-order phase-locked loop is embedded into the equalizer to track the time-varying channel. Meanwhile, by utilizing a weighted linear combining scheme, the conventional soft direct-adaptation based equalizer is combined with the time-reversed soft direct-adaptation based equalizer to exploit bidirectional diversity and mitigate error propagation. Both the simulation and experimental results demonstrate that the soft direct-adaptation based bidirectional turbo equalizer outperforms the single-direction soft direct-adaptation based turbo equalizer, and achieves a faster convergence rate than the hard direct-adaptation based bidirectional turbo equalizer.
基金Supported by the National Natural Science Foundation ofChina(No.61271240)Jiangsu Province Natural Science Fund Project(No.BK2010077)Subject of Twelfth Five Years Plans in Jiangsu Second Normal University(No.417103)
文摘Matrix completion is the extension of compressed sensing.In compressed sensing,we solve the underdetermined equations using sparsity prior of the unknown signals.However,in matrix completion,we solve the underdetermined equations based on sparsity prior in singular values set of the unknown matrix,which also calls low-rank prior of the unknown matrix.This paper firstly introduces basic concept of matrix completion,analyses the matrix suitably used in matrix completion,and shows that such matrix should satisfy two conditions:low rank and incoherence property.Then the paper provides three reconstruction algorithms commonly used in matrix completion:singular value thresholding algorithm,singular value projection,and atomic decomposition for minimum rank approximation,puts forward their shortcoming to know the rank of original matrix.The Projected Gradient Descent based on Soft Thresholding(STPGD),proposed in this paper predicts the rank of unknown matrix using soft thresholding,and iteratives based on projected gradient descent,thus it could estimate the rank of unknown matrix exactly with low computational complexity,this is verified by numerical experiments.We also analyze the convergence and computational complexity of the STPGD algorithm,point out this algorithm is guaranteed to converge,and analyse the number of iterations needed to reach reconstruction error.Compared the computational complexity of the STPGD algorithm to other algorithms,we draw the conclusion that the STPGD algorithm not only reduces the computational complexity,but also improves the precision of the reconstruction solution.
文摘Microstructures and magnetic properties of Fe84Nb7B9,Fe80Ti8B 12 and Fe32Ni36（Nb/V）7Si8B17 powders and their bulk alloys prepared by mechanical alloying（MA） method and hot-press sintering were studied. The results show that: 1) After MA for 20 h,nanocrystalline bcc singl e phase supersaturated solid solution forms in Fe84-Nb7B9 and Fe8 0Ti8B12 alloys,amorphous structure forms in Fe32Ni36Nb7 Si8B17 alloy,duplex microstructure composed of nanocrystalline γ- （FeNi） supersaturated solid solution and trace content of Fe2B phase forms in Fe32Ni36-V7Si8B17 alloy. 2) The decomposition process of supersaturated solid solution phases in Fe84Nb7B9 and Fe80Ti8B 12 alloys happens at 710780 ℃,crystallization reaction in Fe （32）Ni36Nb7Si8B17 alloy happens at 530 ℃（the temperature of peak value） and residual amorphous crystallized further happens at 760 ℃ （the temperature of peak value）,phase decomposition process of supersaturated solid solution at 780 ℃ （the temperature of peak value） and crystallization reaction at 431 ℃ （the temperature of peak value） happens in Fe32Ni36V7S i8B17 alloy. 3) under 900 ℃,30 MPa,（0.5 h） hot-press sintering conditions,bulk alloys with high relative density（94.7%95.8%） can be ob tained. Except that the grain size of Fe84Nb7B9 bulk alloy is large,s uperfine grains （grain size 50200 nm） are obtained in other alloys. Exc ept that single phase microstructure is obtained in Fe80Ti8B12 bul k alloy,multi-phase microstructures are obtained in other alloys. 4) The magne tic properties of Fe80Ti8B12bulk alloy（Bs=1.74 T,Hc= 4.35 kA/m） are significantly superior to those of other bulk alloys,which is r elated to the different phases of nanocrystalline or amorphous powder formed dur ing hot-press sintering process and grain size.
基金Project supported by the National Natural Science of China(Grant Nos.21434001,51561145002,and 11421110001)
文摘When a film of soft matter solutions is being dried, a skin layer often forms at its surface, which is a gel-like elastic phase made of concentrated soft matter solutions. We study the dynamics of this process by using the solute based Lagrangian scheme which was proposed by us recently. In this scheme, the process of the gelation（i.e., the change from sol to gel） can be naturally incorporated in the diffusion equation. Effects of the elasticity of the skin phase, the evaporation rate of the solvents, and the initial concentration of the solutions are discussed. Moreover, the condition for the skin formation is provided.
基金supported by National Natural Science Foundation of China under Grant No. 60873077/F020107the Science Research Project of Zhangzhou Normal University under Grant No. SK09002
文摘Covering-based rough sets process data organized by a covering of the universe. A soft set is a parameterized family of subsets of the universe. Both theories can deal with the uncertainties of data. Soft sets have not any restrictions on the approximate description of the object,and they might form a covering of the universe. From this viewpoint,we establish a connection between these two theories. Specifically,we propose a complementary parameter for this purpose. With this parameter,the soft covering approximation space is established and the two theories are bridged. Furthermore,we study some relations between the covering and the soft covering approximation space and obtain some significant results. Finally,we define a notion of combine parameter which can help us to simplify the set of parameters and reduce the storage requirement of a soft covering approximation space.
文摘Objective To investigate a simple, valuable new method for coverage of the soft tissue defect over the lower one-third of the leg, ankle and the foot. Methods The distally based peroneus brevis muscle fkps were applied for coverage of the soft tissue defects over the lower one-third of the leg,the ankle and the foot. The muscle flaps were covered with split-thickness skin grafts. Results The distally based peroneus brevis muscle flaps were applied for coverage of the soft tissue defects over the lower one-third of the leg, the ankle and the foot in 16 cases. The larges area of the soft tissue defect was 5 cm × 7 cm. The smallest was 3 cm × 4 cm. Primary healing occured in 14 cases undergoing muscle flap construction, second-stage healing occured in 2 cases, no total flap necrosis occured in any cases. Conclusion ThisChina Medical Abstracts(Surgery) technigue is a simple and complication are lesser. The successful rates are higher. This muscle flap is suitable to the mudium or small soft tissue
基金supported by the Guangxi Science and Technology Program(2023AB38061)the National Natural Science Foundation of China(22162004,22479031)the High-performance Computing Platform of Guangxi University。
文摘Co_(3)O_(4) is a promising catalyst for the chlorine evolution reaction(CER)in seawater;however,its CER selectivity is compromised by the adsorption of the competitive oxygen evolution reaction intermediate(OH^(-))at Co sites.Inspired by the hard-soft acid-base(HSAB)theory,this study proposes incorporating early transition metal sites(V)with a low degree of electron delocalization into Co_(3)O_(4) to modulate the selective adsorption of reactants on catalytic sites.Experimental and theoretical calculations reveal that V incorporation facilitates the electron accumulation at the Co site,significantly strengthening the interaction between Co and Cl^(-).Meanwhile,the loss of electrons from V sites generates a more localized electronic state that preferentially adsorbs OH^(-),thus reducing the Co-OH interaction and releasing more Co sites for Cl^(-)adsorption.Therefore,Co_(2)VO_(4) exhibits a high CER selectivity of 92.3%and maintains one of the highest stabilities over 300 h in natural seawater.The resulting half-flow cell achieves~100%disinfection efficiency in seawater,validating the HSAB theory-based design strategy and offering new guidance for developing highly selective seawater CER catalysts.
基金Supported by the National Natural Science Foundation of China(21366008)the Foundation of Guizhou University((2010)040)the Science & Technology Foundation of Guizhou Province((2012)2152)
文摘Catalysts CuOx/γ,-Al2O3-IH and CuOx/γ/-Al2O3-IM were prepared, characterized, and tested for styrene combustion in the absence and presence of water vapor. The effect of copper valence of the catalysts on the catalytic activity for styrene combustion was discussed using the theory of hard soft acids and bases （HSAB）. The results showed that the existence of water vapor in feed stream inhibited the catalytic activity for styrene combustion due to the competition adsorption of water molecule. HSAB theory confirmed that the local soft acidity of the catalyst CuOx/^-AI203-1H was much stronger than that of the catalyst CuOx/^-AI203-1M because of the higher content of soft acid Cu＋ on its surface, which increased the adsorption ability toward soft base of styrene and reduced the adsorption toward hard base of water vapor, and thus increased the catalytic activity for styrene combustion and weakened the negative influence of water vapor.
