The orthogonal time frequency space(OTFS)modulation is a novel modulation scheme that can effectively cope with the high Doppler expansion caused by high mobility.Since it modulates data on delay-Doppler(DD)domain and...The orthogonal time frequency space(OTFS)modulation is a novel modulation scheme that can effectively cope with the high Doppler expansion caused by high mobility.Since it modulates data on delay-Doppler(DD)domain and makes full use of the sparse characteristics of DD domain,it has been widely studied to design efficient channel estimation and signal detection schemes.In this paper,we design a novel superimposed pilot pattern with transition band,which replaces the traditional embedded pilot(EP)guard zero-symbols,and perform a two-stage channel estimation.In the first stage,we fully utilize the dispersion characteristics of OTFS signal in DD domain,and use threshold decision to make coarse channel estimation.In the second stage,we use the results of the coarse estimation for iterative signal detection and accurate channel estimation.During the second stage,we make full use of the sparsity of the channel in DD domain,remodel the received signal into the form of sparse channel vector multiplied by channel coefficient matrix,and introduce Doppler index segmentation factor(DISF)to subdivide the Doppler index to solve the problem of fractional Doppler.Simulations reveal that,the scheme proposed in this paper has higher spectral efficiency compared with traditional EP scheme and lower peak-to-average power ratio(PAPR)compared with traditional superimposed pilot scheme.展开更多
The characteristics of wave transmission, reflection and energy dissipation of comb-type caisson breakwaters are studied through laboratory physical model tests. Regular and irregular waves, with a wide range of wave ...The characteristics of wave transmission, reflection and energy dissipation of comb-type caisson breakwaters are studied through laboratory physical model tests. Regular and irregular waves, with a wide range of wave heights and periods and a constant water depth, are considered. Different dimensions of each portion of the comb-type caisson breakwater are tested. Empirical formulae for calculating the reduction coefficient k, which is the ratio of horizontal wave force on unit length of the comb-type breakwater to that on unit length of the vertical wall breakwater, and for calculating the reflection coefficient of waves k, are obtained from the measurements. The comb-type caisson breakwater has been found to be very efficient in dissipating incident wave energy and in reducing wave reflection, and has already been used for the construction of an island breakwater in the Dayao Bay of Dalian Port, Liaoning Province, China. Compared with the cost of a common caisson breakwater, about 24.5% of the investment has been saved owing to the use of this comb-type breakwater.展开更多
This study develops an analytical solution for oblique wave interaction with a comb-type caisson breakwater based on linear potential theory. The fluid domain is divided into inner and outer regions according to the g...This study develops an analytical solution for oblique wave interaction with a comb-type caisson breakwater based on linear potential theory. The fluid domain is divided into inner and outer regions according to the geometrical shape of breakwater. By using periodic boundary condition and separation of variables, series solutions of velocity potentials in inner and outer regions are developed. Unknown expansion coefficients in series solutions are determined by matching velocity and pressure of continuous conditions on the interface between two regions. Then, hydrodynamic quantities involving reflection coefficients and wave forces acting on breakwater are estimated. Analytical solution is validated by a multi-domain boundary element method solution for the present problem. Diffusion reflection due to periodic variations in breakwater shape and corresponding surface elevations around the breakwater are analyzed. Numerical examples are also presented to examine effects of caisson parameters on total wave forces acting on caissons and total wave forces acting on side plates. Compared with a traditional vertical wall breakwater, the wave force acting on a suitably designed comb-type caisson breakwater can be significantly reduced. This study can give a better understanding of the hydrodynamic performance of comb-type caisson breakwaters.展开更多
The comb-type breakwater(CTB)has been proposed and investigated in recent years due to its advantages in terms of deep-water adaptability,material saving and water exchanges.All existing empirical formulae for CTBs ha...The comb-type breakwater(CTB)has been proposed and investigated in recent years due to its advantages in terms of deep-water adaptability,material saving and water exchanges.All existing empirical formulae for CTBs have been so far restricted to the water level above the bottom of the superstructure,which mainly occurs under the high tides or storm tides.However,based on recent engineering applications and experimental observations,the most severe conditions for CTBs are more likely to occur under a medium water level,because impulsive wave pressure may occur due to interactions between waves and the special chamber in CTBs.Meanwhile,during the most of construction and operation periods,the CTBs are mainly working under the medium water levels,i.e.,water levels below the bottom of the superstructure.In this study,the effects of main influence parameters on the horizontal wave force coefficient and wave transmission coefficient for open CTBs(with partially immersed side plates)under medium water levels were investigated based on a 3D numerical wave flume and corresponding empirical formulae were proposed.It is indicated that the location of the side plate related to the main caisson has significant influence on the hydrodynamic performance of CTBs.In engineering applications,the location of the side plate can be designed at b/L≤0.15 or b/L≥0.3(where b is the distance between the side plate and the front face of the main caisson and L is the incident wave length)for efficiently lowering the horizontal wave force and wave transmission.The flow mechanism of impulsive wave force on CTBs was revealed based on synchronous analyses of flow fields and pressure distribution.Through appropriate design of the height of the superstructure according to H/hD≤1.0 or H/hD≥1.5(where H is the incident wave height and hD is the distance between the still water level and the bottom of the superstructure),the likely impulsive wave pressure on the side plate can also be diminished.展开更多
Dear Editor,Local recurrence and cervical lymph node metastases are major causes of mortality in patients with head and neck squamous cell carcinoma(HNSCC).To date,none of the proposed strategies for predicting outcom...Dear Editor,Local recurrence and cervical lymph node metastases are major causes of mortality in patients with head and neck squamous cell carcinoma(HNSCC).To date,none of the proposed strategies for predicting outcomes in this disease have proven fully effective,and a comprehensive physical examination remains the primary method for early detection and monitoring of HNSCC.展开更多
In this paper,an interference cancellation based neural receiver for superimposed pilot(SIP)in multi-layer transmission is proposed,where the data and pilot are non-orthogonally superimposed in the same time-frequency...In this paper,an interference cancellation based neural receiver for superimposed pilot(SIP)in multi-layer transmission is proposed,where the data and pilot are non-orthogonally superimposed in the same time-frequency resource.Specifically,to deal with the intra-layer and inter-layer interference of SIP under multi-layer transmission,the interference cancellation with superimposed symbol aided channel estimation is leveraged in the neural receiver,accompanied by the pre-design of pilot code-division orthogonal mechanism at transmitter.In addition,to address the complexity issue for inter-vendor collaboration and the generalization problem in practical deployments,respectively,this paper also provides a fixed SIP(F-SIP)design based on constant pilot power ratio and scalable mechanisms for different modulation and coding schemes(MCSs)and transmission layers.Simulation results demonstrate the superiority of the proposed schemes on the performance of block error rate and throughput compared with existing counterparts.展开更多
Dear Editor,In recent years,there has been a significant upward trend in the detection rate of thyroid diseases among military flight personnel[1].Thyroid diseases not only pose a serious threat to the health of fligh...Dear Editor,In recent years,there has been a significant upward trend in the detection rate of thyroid diseases among military flight personnel[1].Thyroid diseases not only pose a serious threat to the health of flight personnel but also have negative impacts on the aviation safety and combat effectiveness of troops.It has been confirmed that the occurrence and progression of thyroid diseases are closely linked to dietary iodine intake.Studies have manifested that long-term excessive or insufficient iodine intake can lead to thyroid diseases[2,3].展开更多
Addressing the environmental issues of traditional vanadium extraction methods from vanadium-bearing shale,a highly efficient and clean suspension oxidation roasting-curing-leaching process was proposed and semi-indus...Addressing the environmental issues of traditional vanadium extraction methods from vanadium-bearing shale,a highly efficient and clean suspension oxidation roasting-curing-leaching process was proposed and semi-industrial trials were conducted.Vanadium in raw ore mainly exists in sericite,roscoelite,and limonite,predominantly in the forms of V(Ⅲ)and V(Ⅳ).Under the conditions of a feed rate of 30 kg/h,an air flow rate of 28.0 m^(3)/h,an O_(2) flow rate of 4.0 m^(3)/h,and a temperature of 900℃ in both the suspension furnace and fluidized reactor,the vanadium-bearing mica underwent dehydroxylation and transformed into illite-montmorillonite.These changes disrupted the crystal structure of mica,facilitating vanadium extraction.Compared to direct acid leaching,curing-leaching demonstrates better performance in vanadium extraction.Under the conditions of curing temperature of 130℃,acid dosage of 40 wt.%,curing time of 6 h,and leaching time of 3 h,a V_(2)O_(5) leaching efficiency of 83.92% was achieved.展开更多
Before nationwide implementation of waste classification programs in rural areas,identifying suitable pilot regions is crucial.This study develops a comprehensive framework for assessing and selecting these pilot regi...Before nationwide implementation of waste classification programs in rural areas,identifying suitable pilot regions is crucial.This study develops a comprehensive framework for assessing and selecting these pilot regions.Data were collected through 654 valid questionnaires and interviews with respondents from rural areas in six provinces across China.Primary assessment criteria included disposal methods for kitchen waste,recyclables,hazardous waste,and residual waste,as well as farmers’willingness to separate hazardous waste when offered compensation and the impact of centralized waste treatment in villages.Secondary criteria focused on disposal methods for agrochemical packages and other hazardous waste.Using the weighted sum of squares method,the study evaluated the suitability of six regions as pilot areas for waste classification.The results identified villages in Jiangsu province and Hebei province as the most suitable pilot regions.Based on the findings,the study provides recommendations to address weaknesses in these regions to enhance the effectiveness of future trials and offers tailored suggestions for other regions to improve their waste classification initiatives.展开更多
A pilot plant integrating pervaporation membrane bioreactor and mechanical vapor compression for bioethanol production was designed and constructed in the study,with a bioethanol production of 300 t·a^(-1).Key eq...A pilot plant integrating pervaporation membrane bioreactor and mechanical vapor compression for bioethanol production was designed and constructed in the study,with a bioethanol production of 300 t·a^(-1).Key equipment in the process were designed based on bench test data.A pilot-scale fermenter with 20 m^(3) in volume,4 m in height and 2.5 m in diameter was designed based on geometric similarity criterion and power equality criterion.An integrated plate-frame membrane module with 105 plates was newly developed.Compared with conventional batch fermentation,the improvement of equipment utilization efficiency and the cell utilization efficiency can be expected as 1.5-2.0 times and 2-10 times,respectively,with waste water reduced by 70% to 85%.The high-exergy energy requirement for pilot plant was 57.5 k W,of which the broth preheater occupied 85.7%,following by the compressor 1.1%,pump1.9% and fermenter agitator 0.3%.The total energy requirement including distillation for producing 1 kg ethanol(95%(mass)) achieved an energy surplus of 15.6 MJ.展开更多
Sewage sludge in cities of Yangzi River Belt,China,generally exhibits a lower organic content and higher silt contentdue to leakage of drainage system,which caused low bioenergy recovery and carbon emission benefits i...Sewage sludge in cities of Yangzi River Belt,China,generally exhibits a lower organic content and higher silt contentdue to leakage of drainage system,which caused low bioenergy recovery and carbon emission benefits in conventional anaerobic digestion(CAD).Therefore,this paper is on a pilot scale,a bio-thermophilic pretreatment anaerobic digestion(BTPAD)for low organic sludge(volatile solids(VS)of 4%)was operated with a long-term continuous flow of 200 days.The VS degradation rate and CH_(4) yield of BTPAD increased by 19.93%and 53.33%,respectively,compared to those of CAD.The analysis of organic compositions in sludge revealed that BTPAD mainly improved the hydrolysis of proteins in sludge.Further analysis of microbial community proportions by high-throughput sequencing revealed that the short-term bio-thermophilic pretreatment was enriched in Clostridiales,Coprothermobacter and Gelria,was capable of hydrolyzing acidified proteins,and provided more volatile fatty acid(VFA)for the subsequent reaction.Biome combined with fluorescence quantitative polymerase chain reaction(PCR)analysis showed that the number of bacteria with high methanogenic capacity in BTPAD was much higher than that in CAD during the medium temperature digestion stage,indicating that short-term bio-thermophilic pretreatment could provide better methanogenic conditions for BTPAD.Furthermore,the greenhouse gas emission footprint analysis showed that short-term bio-thermophilic pretreatment could reduce the carbon emission of sludge anaerobic digestion system by 19.18%.展开更多
Background:Atopic eczema is the most common type of skin disorder in both children and adults.It is characterized by erythema,pruritus,papules,xeransis,and lichenification.The KangminⅠdecoction,a Chinese herbal medic...Background:Atopic eczema is the most common type of skin disorder in both children and adults.It is characterized by erythema,pruritus,papules,xeransis,and lichenification.The KangminⅠdecoction,a Chinese herbal medicine prepared with several ingredients and used to treat eczema,was formulated according to traditional Chinese medicine theory.Objectives:To investigate the efficacy and safety of KangminⅠdecoction for treating atopic eczema compared to that of loratadine.Methods:90 patients were enrolled at the Yueyang Hospital of Integrated Traditional Chinese and Western Medicine and randomly divided into the KangminⅠdecoction treatment group(n=45)and loratadine control group(n=45).Clinical efficacy was evaluated using the Eczema Area and Severity Index(EASI),Dermatology Life Quality Index(DLQI),adverse events(AEs),and recurrence rates,which were compared between the groups.Results:Compared to the loratadine control group(51.16%,18.60%),the KangminⅠdecoction group(7.72%,4.55%)displayed a significantly reduced effective rate(x^(2)=8.324,P=0.040)and recurrence rate(x^(2)=4.225,P=0.040).The incidence of AEs was similar between the groups(P=0.502).Conclusions:These results support further development of KangminⅠdecoction for the treatment of eczema.The KangminⅠdecoction showed good efficacy with a low recurrence rate and tolerable AEs.The main limitations of this study include the small sample size and the short treatment and follow-up periods.Larger controlled studies are needed to more adequately evaluate both safety and efficacy.展开更多
The clinical application of solid lipid particles(SLPs)is hampered due to the need for advanced nano/micro-suspension production technology.This research aims to establish a pilot-scale production line employing high-...The clinical application of solid lipid particles(SLPs)is hampered due to the need for advanced nano/micro-suspension production technology.This research aims to establish a pilot-scale production line employing high-speed shears as emulsification equipment.The primary purpose is to manufacture nano/micro-suspensions using solid lipid particles(SLPs).The study also exhaustively introduces and analyzes the regulatory schemes for process parameters and formulations at various stages of production.The process and formulation endured optimization through orthog-onal or single-factor tests at various production steps:laboratory research,small-scale trial production,and pilot production.Quality standards for the product were determined,and key parameters were obtained at each stage.The laboratory research demonstrated that the optimal SLPs comprised 15 mL 3%polyvinyl alcohol(PVA)per 1.0 g tilmicosin and 2.5 g carnauba wax(WAX).During small-scale production,modifications were made to the volume of the aqueous phase,emulsifier concentration,and emulsification strength,setting them to 16 mL,5%,and 2200 r/min,respectively.In the pilot production stage,the shear time was considered optimal at eight min.The impurity,content,polydispersion coefficient(PDI),and size of the pilot product were<3%,5%,0385 and 2.64μm,respectively.Among the several parameters studied,heating temperature,drug-lipid ratio,and emulsifier concentration were identified as the main factors affecting product quality,and they were regulated at 100℃,1:3,and 5%,respectively.A novel hot melt emulsification shear method aided the development of a new solid lipid-based suspension from its preliminary stages in the laboratory to pilot production.This innovation is expected to enhance solid lipid-based suspensions'industrial evolution extensively.展开更多
Cross-border e-commerce has emerged as a new growth point in foreign trade.While the Dalian comprehensive pilot zone has made some progress,its development is constrained by issues such as the global economic slowdown...Cross-border e-commerce has emerged as a new growth point in foreign trade.While the Dalian comprehensive pilot zone has made some progress,its development is constrained by issues such as the global economic slowdown,the relatively small scale of cross-border e-commerce,a high concentration of export commodities,imperfect information mechanisms,and high overall costs.To address these challenges,this paper explores the importance of the construction of the Dalian comprehensive pilot zone for cross-border e-commerce to the transformation and upgrading of exports.Based on my research project,“Research on Path Optimization of Financial Support for the Development of Advanced Manufacturing Clusters in Dalian,”this paper analyzes the current challenges and limiting factors and proposes corresponding countermeasures and suggestions.展开更多
Coal dependence and inefficient decentralized heating have significantly increased China’s energy consumption for winter heating,increasing air pollution and exacerbating the greenhouse effect.In 2017,China implement...Coal dependence and inefficient decentralized heating have significantly increased China’s energy consumption for winter heating,increasing air pollution and exacerbating the greenhouse effect.In 2017,China implemented the Pilot Policy on Clean Winter Heating in Northern China,aiming to achieve high central heating coverage and cleaner energy consumption.Studying the effects of this policy can help promote its implementation and serve as a reference for effective adjustment of the contents in the future.However,few studies have investigated this policy and its carbon reduction effects,and most focus on the provincial or city levels.Therefore,this paper considers the policy’s influence on air pollution and carbon emissions at the county level to provide a precise and comprehensive assessment of the policy effects.We use panel data from 1290 counties in 15 provinces in Northern China from 2014 to 2021,applying a multiperiod difference-in-differences model to quantify the impact of the policy on carbon emissions and air quality in the pilot area.We then conduct a series of tests to demonstrate the robustness of the results and analyze the mechanisms of the policy effects from two perspectives,namely,central heating and natural gas use,through a mediating effect model.Finally,we examine the heterogeneity of policy effects between counties based on geographic location and per capita income levels of rural residents through a moderating effect model.The results reveal that the policy significantly reduces air pollution and carbon emissions in the pilot area by increasing the central heating area and natural gas use.Compared with the central and western regions in the north and areas with low-income rural residents,the policy effects in the eastern regions in the north and areas with high-income rural residents are more pronounced.展开更多
This study explores the mechanisms by which China’s pilot carbon emissions trading schemes(ETS)facilitate industrial low-carbon transitions.We construct a theoretical model and conduct an empirical analysis using pro...This study explores the mechanisms by which China’s pilot carbon emissions trading schemes(ETS)facilitate industrial low-carbon transitions.We construct a theoretical model and conduct an empirical analysis using provincial panel data from seven pilot provinces spanning 2006-2021.Applying a multi-period difference-in-differences(DID)approach,we evaluate the environmental and economic impacts of the pilot ETS policies.The findings yield three key insights:(1)The pilot ETS significantly reduces carbon emission intensity and improves low-carbon total factor productivity(TFP),thereby promoting China’s industrial low-carbon transition.(2)Mechanism analysis indicates that the ETS primarily operates through cost constraints and industrial structural upgrading,while the effect of technological progress has yet to fully materialize.(3)Heterogeneity analysis reveals that the policy’s effects are more significant in regions with higher levels of economic development and R&D investment,leading to greater carbon intensity reductions and productivity gains.In addition,regions with higher foreign direct investment(FDI)experience more substantial improvements in low-carbon TFP,possibly reflecting technology spillover effects.展开更多
This study utilizes panel data from 293 Chinese cities at the prefecture level or above,spanning from 2013 to 2022,to empirically examine the net effects and underlying mechanisms of establishing pilot free trade zone...This study utilizes panel data from 293 Chinese cities at the prefecture level or above,spanning from 2013 to 2022,to empirically examine the net effects and underlying mechanisms of establishing pilot free trade zones(FTZs)on integration into the digital global value chain(DGVC).The results demonstrate that the establishment of pilot FTZs positively promotes integration into the DGVC and generates a spatial spillover effect.Compared to coastal areas and small-and medium-sized cities,pilot FTZs have a more significant impact on the integration of inland regions and large cities into the DGVC.Mechanism tests reveal that pilot FTZs drive integration into the DGVC primarily by promoting digital industry agglomeration and enhancing the technological content of exports.Furthermore,bilateral foreign direct investment and digital trade rules positively amplify the impact of pilot FTZs on integration into the DGVC.Therefore,this study recommends comprehensively deepening the development of pilot FTZs,consistently enhancing the technological content of exports,and proactively establishing a sound digital trade regulatory framework.These recommendations offer valuable insights for DGVC integration and the construction of a high-standard free trade network.展开更多
基金supported by National Natural Science Foundation(NNSF)of China under Grant 62001351the Foundation of National Key Laboratory of Electromagnetic Environment(6142403220202)the Stability Support Fund for Basic Military Industrial Research Institutes(A240104130).
文摘The orthogonal time frequency space(OTFS)modulation is a novel modulation scheme that can effectively cope with the high Doppler expansion caused by high mobility.Since it modulates data on delay-Doppler(DD)domain and makes full use of the sparse characteristics of DD domain,it has been widely studied to design efficient channel estimation and signal detection schemes.In this paper,we design a novel superimposed pilot pattern with transition band,which replaces the traditional embedded pilot(EP)guard zero-symbols,and perform a two-stage channel estimation.In the first stage,we fully utilize the dispersion characteristics of OTFS signal in DD domain,and use threshold decision to make coarse channel estimation.In the second stage,we use the results of the coarse estimation for iterative signal detection and accurate channel estimation.During the second stage,we make full use of the sparsity of the channel in DD domain,remodel the received signal into the form of sparse channel vector multiplied by channel coefficient matrix,and introduce Doppler index segmentation factor(DISF)to subdivide the Doppler index to solve the problem of fractional Doppler.Simulations reveal that,the scheme proposed in this paper has higher spectral efficiency compared with traditional EP scheme and lower peak-to-average power ratio(PAPR)compared with traditional superimposed pilot scheme.
基金This paper presents part of the achievement in the China National Key Project"Construction Techniques for Breakwa-ters in Deep Water"(96-415-02-03)
文摘The characteristics of wave transmission, reflection and energy dissipation of comb-type caisson breakwaters are studied through laboratory physical model tests. Regular and irregular waves, with a wide range of wave heights and periods and a constant water depth, are considered. Different dimensions of each portion of the comb-type caisson breakwater are tested. Empirical formulae for calculating the reduction coefficient k, which is the ratio of horizontal wave force on unit length of the comb-type breakwater to that on unit length of the vertical wall breakwater, and for calculating the reflection coefficient of waves k, are obtained from the measurements. The comb-type caisson breakwater has been found to be very efficient in dissipating incident wave energy and in reducing wave reflection, and has already been used for the construction of an island breakwater in the Dayao Bay of Dalian Port, Liaoning Province, China. Compared with the cost of a common caisson breakwater, about 24.5% of the investment has been saved owing to the use of this comb-type breakwater.
基金supported by the National Natural Science Foundation of China(Nos.51490675,51322903 and 51279224)
文摘This study develops an analytical solution for oblique wave interaction with a comb-type caisson breakwater based on linear potential theory. The fluid domain is divided into inner and outer regions according to the geometrical shape of breakwater. By using periodic boundary condition and separation of variables, series solutions of velocity potentials in inner and outer regions are developed. Unknown expansion coefficients in series solutions are determined by matching velocity and pressure of continuous conditions on the interface between two regions. Then, hydrodynamic quantities involving reflection coefficients and wave forces acting on breakwater are estimated. Analytical solution is validated by a multi-domain boundary element method solution for the present problem. Diffusion reflection due to periodic variations in breakwater shape and corresponding surface elevations around the breakwater are analyzed. Numerical examples are also presented to examine effects of caisson parameters on total wave forces acting on caissons and total wave forces acting on side plates. Compared with a traditional vertical wall breakwater, the wave force acting on a suitably designed comb-type caisson breakwater can be significantly reduced. This study can give a better understanding of the hydrodynamic performance of comb-type caisson breakwaters.
基金financially supported by the General Program of the National Natural Science Foundation of China(Grant No.51979192)the National Key Rsearch and Development Program of China(Grant Nos.2020YFE0201200 and 2021YFB2600700)the Program of China Communications Construction Company Limited(Grant No.2018-ZJKJ-01).
文摘The comb-type breakwater(CTB)has been proposed and investigated in recent years due to its advantages in terms of deep-water adaptability,material saving and water exchanges.All existing empirical formulae for CTBs have been so far restricted to the water level above the bottom of the superstructure,which mainly occurs under the high tides or storm tides.However,based on recent engineering applications and experimental observations,the most severe conditions for CTBs are more likely to occur under a medium water level,because impulsive wave pressure may occur due to interactions between waves and the special chamber in CTBs.Meanwhile,during the most of construction and operation periods,the CTBs are mainly working under the medium water levels,i.e.,water levels below the bottom of the superstructure.In this study,the effects of main influence parameters on the horizontal wave force coefficient and wave transmission coefficient for open CTBs(with partially immersed side plates)under medium water levels were investigated based on a 3D numerical wave flume and corresponding empirical formulae were proposed.It is indicated that the location of the side plate related to the main caisson has significant influence on the hydrodynamic performance of CTBs.In engineering applications,the location of the side plate can be designed at b/L≤0.15 or b/L≥0.3(where b is the distance between the side plate and the front face of the main caisson and L is the incident wave length)for efficiently lowering the horizontal wave force and wave transmission.The flow mechanism of impulsive wave force on CTBs was revealed based on synchronous analyses of flow fields and pressure distribution.Through appropriate design of the height of the superstructure according to H/hD≤1.0 or H/hD≥1.5(where H is the incident wave height and hD is the distance between the still water level and the bottom of the superstructure),the likely impulsive wave pressure on the side plate can also be diminished.
文摘Dear Editor,Local recurrence and cervical lymph node metastases are major causes of mortality in patients with head and neck squamous cell carcinoma(HNSCC).To date,none of the proposed strategies for predicting outcomes in this disease have proven fully effective,and a comprehensive physical examination remains the primary method for early detection and monitoring of HNSCC.
文摘In this paper,an interference cancellation based neural receiver for superimposed pilot(SIP)in multi-layer transmission is proposed,where the data and pilot are non-orthogonally superimposed in the same time-frequency resource.Specifically,to deal with the intra-layer and inter-layer interference of SIP under multi-layer transmission,the interference cancellation with superimposed symbol aided channel estimation is leveraged in the neural receiver,accompanied by the pre-design of pilot code-division orthogonal mechanism at transmitter.In addition,to address the complexity issue for inter-vendor collaboration and the generalization problem in practical deployments,respectively,this paper also provides a fixed SIP(F-SIP)design based on constant pilot power ratio and scalable mechanisms for different modulation and coding schemes(MCSs)and transmission layers.Simulation results demonstrate the superiority of the proposed schemes on the performance of block error rate and throughput compared with existing counterparts.
基金supported by the Military Medical Science and Technology Youth Cultivation Program of the Chinese PLA(17QNP023)the Key Projects of Medical Service Scientific Research of the Navy Medical Center(20M2302)the Military Logistics National Military Standard General Project of Chinese PLA(BHJ22B002).
文摘Dear Editor,In recent years,there has been a significant upward trend in the detection rate of thyroid diseases among military flight personnel[1].Thyroid diseases not only pose a serious threat to the health of flight personnel but also have negative impacts on the aviation safety and combat effectiveness of troops.It has been confirmed that the occurrence and progression of thyroid diseases are closely linked to dietary iodine intake.Studies have manifested that long-term excessive or insufficient iodine intake can lead to thyroid diseases[2,3].
基金funded by the National Key Research and Development Program of China(No.2020YFC1909704)the Fundamental Research Funds for the Central Universities,China(Nos.N2301026,N2301017).
文摘Addressing the environmental issues of traditional vanadium extraction methods from vanadium-bearing shale,a highly efficient and clean suspension oxidation roasting-curing-leaching process was proposed and semi-industrial trials were conducted.Vanadium in raw ore mainly exists in sericite,roscoelite,and limonite,predominantly in the forms of V(Ⅲ)and V(Ⅳ).Under the conditions of a feed rate of 30 kg/h,an air flow rate of 28.0 m^(3)/h,an O_(2) flow rate of 4.0 m^(3)/h,and a temperature of 900℃ in both the suspension furnace and fluidized reactor,the vanadium-bearing mica underwent dehydroxylation and transformed into illite-montmorillonite.These changes disrupted the crystal structure of mica,facilitating vanadium extraction.Compared to direct acid leaching,curing-leaching demonstrates better performance in vanadium extraction.Under the conditions of curing temperature of 130℃,acid dosage of 40 wt.%,curing time of 6 h,and leaching time of 3 h,a V_(2)O_(5) leaching efficiency of 83.92% was achieved.
基金supported by the Yunnan Provincial Education Department Scientific Research Fund Project(Grant No.2022J0525).
文摘Before nationwide implementation of waste classification programs in rural areas,identifying suitable pilot regions is crucial.This study develops a comprehensive framework for assessing and selecting these pilot regions.Data were collected through 654 valid questionnaires and interviews with respondents from rural areas in six provinces across China.Primary assessment criteria included disposal methods for kitchen waste,recyclables,hazardous waste,and residual waste,as well as farmers’willingness to separate hazardous waste when offered compensation and the impact of centralized waste treatment in villages.Secondary criteria focused on disposal methods for agrochemical packages and other hazardous waste.Using the weighted sum of squares method,the study evaluated the suitability of six regions as pilot areas for waste classification.The results identified villages in Jiangsu province and Hebei province as the most suitable pilot regions.Based on the findings,the study provides recommendations to address weaknesses in these regions to enhance the effectiveness of future trials and offers tailored suggestions for other regions to improve their waste classification initiatives.
基金supported by the National Key Research and Development Program of China(2021YFC2101204)the Natural Science Foundation of Sichuan Province(2025ZNSFSC0926)the Fundamental Research Funds for the Central Universities(2023SCU12080 and 20822041B4013)。
文摘A pilot plant integrating pervaporation membrane bioreactor and mechanical vapor compression for bioethanol production was designed and constructed in the study,with a bioethanol production of 300 t·a^(-1).Key equipment in the process were designed based on bench test data.A pilot-scale fermenter with 20 m^(3) in volume,4 m in height and 2.5 m in diameter was designed based on geometric similarity criterion and power equality criterion.An integrated plate-frame membrane module with 105 plates was newly developed.Compared with conventional batch fermentation,the improvement of equipment utilization efficiency and the cell utilization efficiency can be expected as 1.5-2.0 times and 2-10 times,respectively,with waste water reduced by 70% to 85%.The high-exergy energy requirement for pilot plant was 57.5 k W,of which the broth preheater occupied 85.7%,following by the compressor 1.1%,pump1.9% and fermenter agitator 0.3%.The total energy requirement including distillation for producing 1 kg ethanol(95%(mass)) achieved an energy surplus of 15.6 MJ.
基金supported by the National Key Research and Development Project (Nos.2020YFC1908702 and 2021YFC3200700)the National Natural Science Foundation of China (Nos.52192684 and 52192680).
文摘Sewage sludge in cities of Yangzi River Belt,China,generally exhibits a lower organic content and higher silt contentdue to leakage of drainage system,which caused low bioenergy recovery and carbon emission benefits in conventional anaerobic digestion(CAD).Therefore,this paper is on a pilot scale,a bio-thermophilic pretreatment anaerobic digestion(BTPAD)for low organic sludge(volatile solids(VS)of 4%)was operated with a long-term continuous flow of 200 days.The VS degradation rate and CH_(4) yield of BTPAD increased by 19.93%and 53.33%,respectively,compared to those of CAD.The analysis of organic compositions in sludge revealed that BTPAD mainly improved the hydrolysis of proteins in sludge.Further analysis of microbial community proportions by high-throughput sequencing revealed that the short-term bio-thermophilic pretreatment was enriched in Clostridiales,Coprothermobacter and Gelria,was capable of hydrolyzing acidified proteins,and provided more volatile fatty acid(VFA)for the subsequent reaction.Biome combined with fluorescence quantitative polymerase chain reaction(PCR)analysis showed that the number of bacteria with high methanogenic capacity in BTPAD was much higher than that in CAD during the medium temperature digestion stage,indicating that short-term bio-thermophilic pretreatment could provide better methanogenic conditions for BTPAD.Furthermore,the greenhouse gas emission footprint analysis showed that short-term bio-thermophilic pretreatment could reduce the carbon emission of sludge anaerobic digestion system by 19.18%.
基金sponsored by the National Key Research and Development Program(No.2024YFC3500314)the National Natural Science Foundation of China(No.82405403)+3 种基金the Shanghai 2022‘Science and Technology Innovation Action Plan’Medical Innovation Research Special Project(No.22Y11922200)the Key Discipline Construction Project of Shanghai’s Three Year Action Plan for Strengthening the Construction of Public Health System(No.GWVI-11.1-24)the Clinical Research plan of Shanghai Shenkang HospitalDevelopment Center(No.SHDC22022302)the High-level Chinese Medicine Key Discipline Construction Project(Integrative Chinese and Western Medicine Clinic)of National Administration of TCM(No.zyyzdxk-2023065).
文摘Background:Atopic eczema is the most common type of skin disorder in both children and adults.It is characterized by erythema,pruritus,papules,xeransis,and lichenification.The KangminⅠdecoction,a Chinese herbal medicine prepared with several ingredients and used to treat eczema,was formulated according to traditional Chinese medicine theory.Objectives:To investigate the efficacy and safety of KangminⅠdecoction for treating atopic eczema compared to that of loratadine.Methods:90 patients were enrolled at the Yueyang Hospital of Integrated Traditional Chinese and Western Medicine and randomly divided into the KangminⅠdecoction treatment group(n=45)and loratadine control group(n=45).Clinical efficacy was evaluated using the Eczema Area and Severity Index(EASI),Dermatology Life Quality Index(DLQI),adverse events(AEs),and recurrence rates,which were compared between the groups.Results:Compared to the loratadine control group(51.16%,18.60%),the KangminⅠdecoction group(7.72%,4.55%)displayed a significantly reduced effective rate(x^(2)=8.324,P=0.040)and recurrence rate(x^(2)=4.225,P=0.040).The incidence of AEs was similar between the groups(P=0.502).Conclusions:These results support further development of KangminⅠdecoction for the treatment of eczema.The KangminⅠdecoction showed good efficacy with a low recurrence rate and tolerable AEs.The main limitations of this study include the small sample size and the short treatment and follow-up periods.Larger controlled studies are needed to more adequately evaluate both safety and efficacy.
基金supported by the Fundamental Research Funds for the Central Universities(2662020DKPY008)the National Natural Science Foundation of China(grant No.31772797)。
文摘The clinical application of solid lipid particles(SLPs)is hampered due to the need for advanced nano/micro-suspension production technology.This research aims to establish a pilot-scale production line employing high-speed shears as emulsification equipment.The primary purpose is to manufacture nano/micro-suspensions using solid lipid particles(SLPs).The study also exhaustively introduces and analyzes the regulatory schemes for process parameters and formulations at various stages of production.The process and formulation endured optimization through orthog-onal or single-factor tests at various production steps:laboratory research,small-scale trial production,and pilot production.Quality standards for the product were determined,and key parameters were obtained at each stage.The laboratory research demonstrated that the optimal SLPs comprised 15 mL 3%polyvinyl alcohol(PVA)per 1.0 g tilmicosin and 2.5 g carnauba wax(WAX).During small-scale production,modifications were made to the volume of the aqueous phase,emulsifier concentration,and emulsification strength,setting them to 16 mL,5%,and 2200 r/min,respectively.In the pilot production stage,the shear time was considered optimal at eight min.The impurity,content,polydispersion coefficient(PDI),and size of the pilot product were<3%,5%,0385 and 2.64μm,respectively.Among the several parameters studied,heating temperature,drug-lipid ratio,and emulsifier concentration were identified as the main factors affecting product quality,and they were regulated at 100℃,1:3,and 5%,respectively.A novel hot melt emulsification shear method aided the development of a new solid lipid-based suspension from its preliminary stages in the laboratory to pilot production.This innovation is expected to enhance solid lipid-based suspensions'industrial evolution extensively.
文摘Cross-border e-commerce has emerged as a new growth point in foreign trade.While the Dalian comprehensive pilot zone has made some progress,its development is constrained by issues such as the global economic slowdown,the relatively small scale of cross-border e-commerce,a high concentration of export commodities,imperfect information mechanisms,and high overall costs.To address these challenges,this paper explores the importance of the construction of the Dalian comprehensive pilot zone for cross-border e-commerce to the transformation and upgrading of exports.Based on my research project,“Research on Path Optimization of Financial Support for the Development of Advanced Manufacturing Clusters in Dalian,”this paper analyzes the current challenges and limiting factors and proposes corresponding countermeasures and suggestions.
基金supported by the National Social Science Fund of China[Grant No.21BGL181]to Yan Chen.
文摘Coal dependence and inefficient decentralized heating have significantly increased China’s energy consumption for winter heating,increasing air pollution and exacerbating the greenhouse effect.In 2017,China implemented the Pilot Policy on Clean Winter Heating in Northern China,aiming to achieve high central heating coverage and cleaner energy consumption.Studying the effects of this policy can help promote its implementation and serve as a reference for effective adjustment of the contents in the future.However,few studies have investigated this policy and its carbon reduction effects,and most focus on the provincial or city levels.Therefore,this paper considers the policy’s influence on air pollution and carbon emissions at the county level to provide a precise and comprehensive assessment of the policy effects.We use panel data from 1290 counties in 15 provinces in Northern China from 2014 to 2021,applying a multiperiod difference-in-differences model to quantify the impact of the policy on carbon emissions and air quality in the pilot area.We then conduct a series of tests to demonstrate the robustness of the results and analyze the mechanisms of the policy effects from two perspectives,namely,central heating and natural gas use,through a mediating effect model.Finally,we examine the heterogeneity of policy effects between counties based on geographic location and per capita income levels of rural residents through a moderating effect model.The results reveal that the policy significantly reduces air pollution and carbon emissions in the pilot area by increasing the central heating area and natural gas use.Compared with the central and western regions in the north and areas with low-income rural residents,the policy effects in the eastern regions in the north and areas with high-income rural residents are more pronounced.
基金Major Project of the National Social Science Foundation of China(NSSFC)-“Study on the Construction of China’s Unified Carbon Market and the Realization Mechanism of the‘Dual Carbon’Goal”(Grant No.24VRC003).
文摘This study explores the mechanisms by which China’s pilot carbon emissions trading schemes(ETS)facilitate industrial low-carbon transitions.We construct a theoretical model and conduct an empirical analysis using provincial panel data from seven pilot provinces spanning 2006-2021.Applying a multi-period difference-in-differences(DID)approach,we evaluate the environmental and economic impacts of the pilot ETS policies.The findings yield three key insights:(1)The pilot ETS significantly reduces carbon emission intensity and improves low-carbon total factor productivity(TFP),thereby promoting China’s industrial low-carbon transition.(2)Mechanism analysis indicates that the ETS primarily operates through cost constraints and industrial structural upgrading,while the effect of technological progress has yet to fully materialize.(3)Heterogeneity analysis reveals that the policy’s effects are more significant in regions with higher levels of economic development and R&D investment,leading to greater carbon intensity reductions and productivity gains.In addition,regions with higher foreign direct investment(FDI)experience more substantial improvements in low-carbon TFP,possibly reflecting technology spillover effects.
基金supported by the Key Project of the Hainan Province Marxist Theory Research and Development Program,titled“Research on the Opportunities and Challenges of the Digital Economy Partnership Agreement(DEPA)for the Construction of the Hainan Free Trade Port”(Grant Number:2023HNMGC02).
文摘This study utilizes panel data from 293 Chinese cities at the prefecture level or above,spanning from 2013 to 2022,to empirically examine the net effects and underlying mechanisms of establishing pilot free trade zones(FTZs)on integration into the digital global value chain(DGVC).The results demonstrate that the establishment of pilot FTZs positively promotes integration into the DGVC and generates a spatial spillover effect.Compared to coastal areas and small-and medium-sized cities,pilot FTZs have a more significant impact on the integration of inland regions and large cities into the DGVC.Mechanism tests reveal that pilot FTZs drive integration into the DGVC primarily by promoting digital industry agglomeration and enhancing the technological content of exports.Furthermore,bilateral foreign direct investment and digital trade rules positively amplify the impact of pilot FTZs on integration into the DGVC.Therefore,this study recommends comprehensively deepening the development of pilot FTZs,consistently enhancing the technological content of exports,and proactively establishing a sound digital trade regulatory framework.These recommendations offer valuable insights for DGVC integration and the construction of a high-standard free trade network.
