Aiming at the global design issue of transpiration cooling thermal protection system,a self-driven circulation loop is proposed as the internal coolant flow passage for the transpiration cooling structure to achieve a...Aiming at the global design issue of transpiration cooling thermal protection system,a self-driven circulation loop is proposed as the internal coolant flow passage for the transpiration cooling structure to achieve adaptive cooling.To enhance the universality of this internal cooling pipe design and facilitate its application,numerical studies are conducted on this systemwith four commonly used cooling mediums as coolant.Firstly,the accuracy of the numerical method is verified through an established experimental platform.Then,transient numerical simulations are performed on the flow states of different cooling mediums in the new self-circulation system.Based on the numerical result,the flow,phase change,and heat transfer characteristics of different cooling mediums are analyzed.Differences in fluid velocity and latent heat of phase change result in significant variation in heat exchange capacity among different coolingmediums,with the maximumdifference reaching up to 3 times.Besides,faster circulation speed leads to greater heat transfer capacity,with a maximum of 7600 W/m^(2).Consequently,the operating mechanism and cooling laws of the natural circulation system is further investigated,providing a reference for the practical application of this system.展开更多
By combining the merits of radiative cooling(RC)and evaporation cooling(EC),radiative coupled evaporative cooling(REC)has attracted considerable attention for sub-ambient cooling purposes.However,for outdoor devices,t...By combining the merits of radiative cooling(RC)and evaporation cooling(EC),radiative coupled evaporative cooling(REC)has attracted considerable attention for sub-ambient cooling purposes.However,for outdoor devices,the interior heating power would increase the working temperature and fire risk,which would suppress their above-ambient heat dissipation capabilities and passive water cycle properties.In this work,we introduced a REC design based on an all-in-one photonic hydrogel for above-ambient heat dissipation and flame retardancy.Unlike conventional design RC film for heat dissipation with limited cooling power and fire risk,REC hydrogel can greatly improve the heat dissipation performance in the daytime with a high workload,indicating a 12.0℃lower temperature than the RC film under the same conditions in the outdoor experiment.In the nighttime with a low workload,RC-assisted adsorption can improve atmospheric water harvesting to ensure EC in the daytime.In addition,our REC hydrogel significantly enhanced flame retardancy by absorbing heat without a corresponding temperature rise,thus mitigating fire risks.Thus,our design shows a promising solution for the thermal management of outdoor devices,delivering outstanding performance in both heat dissipation and flame retardancy.展开更多
CHINA.Dinghu Mountain National Nature Reserve.Located in Zhaoqing,Guangdong Province,Dinghu Mountain National Nature Reserve is a pristine natural sanctuary spanning 1,133 hectares within the low mountain ranges of th...CHINA.Dinghu Mountain National Nature Reserve.Located in Zhaoqing,Guangdong Province,Dinghu Mountain National Nature Reserve is a pristine natural sanctuary spanning 1,133 hectares within the low mountain ranges of the Dayunwu Mountains.展开更多
Radiative cooling systems(RCSs)possess the distinctive capability to dissipate heat energy via solar and thermal radiation,making them suitable for thermal regulation and energy conservation applications,essential for...Radiative cooling systems(RCSs)possess the distinctive capability to dissipate heat energy via solar and thermal radiation,making them suitable for thermal regulation and energy conservation applications,essential for mitigating the energy crisis.A comprehensive review connecting the advancements in engineered radiative cooling systems(ERCSs),encompassing material and structural design as well as thermal and energy-related applications,is currently absent.Herein,this review begins with a concise summary of the essential concepts of ERCSs,followed by an introduction to engineered materials and structures,containing nature-inspired designs,chromatic materials,meta-structural configurations,and multilayered constructions.It subsequently encapsulates the primary applications,including thermal-regulating textiles and energy-saving devices.Next,it highlights the challenges of ERCSs,including maximized thermoregulatory effects,environmental adaptability,scalability and sustainability,and interdisciplinary integration.It seeks to offer direction for forthcoming fundamental research and industrial advancement of radiative cooling systems in real-world applications.展开更多
Natural product(NPT)derived from traditional Chinese medicine has a rich history as an integral part of Chinese healthcare for thousands of years.Recently,the application of NPT in sonodynamic antibacterial therapy(SD...Natural product(NPT)derived from traditional Chinese medicine has a rich history as an integral part of Chinese healthcare for thousands of years.Recently,the application of NPT in sonodynamic antibacterial therapy(SDAT)has emerged as a promising area of research.This perspective summarizes the recent NPT-based sonosensitizers in SDAT.Currently,common NPT-based sonosensitizers include curcumin,chlorophyll derivatives,hypericin,and berberine.Compared with other sonosensitizers,natural sources of NPT-based sonosensitizers with reactive oxide species production performance under ultrasound conditions,low biotoxicity,and other additional biological activity make them have application prospects in bacterial removal.Finally,the potential benefits and challenges of NPT-based nanosonosensitizers were also discussed.展开更多
Two schemes（scheme Ⅰ and scheme Ⅱ）for designing a district cooling system（DCS）utilizing cold energy of liquefied natural gas（LNG）are presented.In scheme Ⅰ,LNG cold energy is used to produce ice,and then ice i...Two schemes（scheme Ⅰ and scheme Ⅱ）for designing a district cooling system（DCS）utilizing cold energy of liquefied natural gas（LNG）are presented.In scheme Ⅰ,LNG cold energy is used to produce ice,and then ice is transported to the central cooling plant of the DCS.In scheme Ⅱ,return water from the DCS is directly chilled by LNG cold energy,and the chilled water is then sent back to the central plant.The heat transportation loss is the main negative impact in the DCS and is emphatically analyzed when evaluating the efficiency of each scheme.The results show that the DCS utilizing LNG cold energy is feasible and valuable.The cooling supply distance of scheme Ⅱ is limited within 13 km while scheme Ⅰ has no distance limit.When the distance is between 6 and 13 km,scheme Ⅱ is more practical and effective.Contrarily,scheme Ⅰ has a better economic performance when the distance is shorter than 6 km or longer than 13 km.展开更多
This article reports the findings on the adverse effect of the crosswind on the performance of natural draft cooling towers through numerical computation with the k-epsilon eddy-viscosity turbulence model. It is obser...This article reports the findings on the adverse effect of the crosswind on the performance of natural draft cooling towers through numerical computation with the k-epsilon eddy-viscosity turbulence model. It is observed here that the cause of the adverse effect of the crosswind on the cooling towers call be attributed to the around flow effect which destroys the radial inflow into the cooling towers when the wind is absent. Hence, a significant deterioration in the heat transfer from the heat exchangers at lateral sides occurs.展开更多
Concentrating solar thermal power system can provide low carbon,renewable energy resources in countries or regions with strong solar irradiation.For this kind of power plant which is likely to be located in the arid a...Concentrating solar thermal power system can provide low carbon,renewable energy resources in countries or regions with strong solar irradiation.For this kind of power plant which is likely to be located in the arid area,natural draft dry cooling tower is a promising choice.To develop the experimental studies on small cooling tower,a 20 m high natural draft dry cooling tower with fully instrumented measurement system was established by the Queensland Geothermal Energy Centre of Excellence.The performance of this cooling tower was measured with the constant heat input of 600 kW and 840 kW and with ambient temperature ranging from 20 ℃ to 32 ℃.The cooling tower numerical model was refined and validated with the experimental data.The model of 1 MW concentrating solar thermal supercritical CO2 power cycle was developed and integrated with the cooling tower model.The influences of changing ambient temperature and the performance of the cooling tower on efficiency of the power system were simulated.The differences of the mechanism of the ambient temperature effect on Rankine cycle and supercritical CO2 Brayton cycle were analysed and discussed.展开更多
The cooling process of cooling water is veryimportant in power generation industry.The performanceof cooling towers has a great effect on security,stabilityand economy of power plants.The energy savingproblems of the ...The cooling process of cooling water is veryimportant in power generation industry.The performanceof cooling towers has a great effect on security,stabilityand economy of power plants.The energy savingproblems of the cooling tower have always beenneglected previously.With the aim of energy saving inthe power plants nowadays,improving the coolingefficiency of the cooling tower has important andpractical significance.展开更多
This study investigates the performance of a natural draft dry cooling tower group in crosswind conditions through numerical analysis.A comprehensive three-dimensional model is developed to analyze the steady-state an...This study investigates the performance of a natural draft dry cooling tower group in crosswind conditions through numerical analysis.A comprehensive three-dimensional model is developed to analyze the steady-state and dynamic behavior of the towers.The impact of wind speed and direction on heat rejection capacity and flow patterns is examined.Results indicate that crosswinds negatively affect the overall heat transfer capacity,with higher crosswind speeds leading to decreased heat transfer.Notably,wind direction plays a significant role,particularly at 0°.Moreover,tower response time increases with higher crosswind speeds due to increased turbulence and the formation of vortices.The response times are generally similar for wind directions of 45°and 90°,but differ when facing 0,where the leeward tower exhibits a shorter response time compared to the windward tower.These findings provide valuable insights into the performance of natural draft dry cooling tower groups under crosswind conditions,which can inform the design and operation of similar systems in practical applications.展开更多
Large-span air-conditioning plant rooms have a large roof area and suffer from serious solar radiation in summer. The outside roof surface temperature is very high, so cooling load of roof occupies a large proportion ...Large-span air-conditioning plant rooms have a large roof area and suffer from serious solar radiation in summer. The outside roof surface temperature is very high, so cooling load of roof occupies a large proportion in the envelope structure cooling load of large-span air-conditioning plant rooms. Based on the Coanda airfoil air induction unit, the author combined with exhaust air in large-span air-conditioning plant rooms to design the roof air film cooling system of large-span air-conditioning plant rooms. The adherence air film formed on the outside surface takes away heat on the outside surface of the roof, so as to reduce outside roof surface temperature of the roof, decrease heat transfer temperature difference between inside and outside roof surfaces of, and reduce roof cooling cold. Furthermore, the mathematical model and numerical simulation method of considering fluid-structure interaction for heat transfer and influences of solar radiation on air film formation of outside surface and cooling were constructed. Moreover, the numerical simulation method was conducted the validation of effectiveness. Also, the author discussed the air film formation mechanism and air film cooling ability of outside surface in large-span air-conditioning plant rooms without natural wind, developed a new air film cooling technology for the roof of large-span air-conditioning plant rooms, and supplemented the existing roof cooling technology.展开更多
Different aerodynamics calculation methods for three designed cooling towers are compared. Verifications are made by using the field test data of the three operating cooling towers. It is proposed that the wind effect...Different aerodynamics calculation methods for three designed cooling towers are compared. Verifications are made by using the field test data of the three operating cooling towers. It is proposed that the wind effects on water temperature after cooled by tower shall be considered in the cooling tower design; the Hamon calculation method is one of the feasible method; the method of adding the resistance coefficients of various parts of cooling tower should not be used.展开更多
Passive cooling techniques are cost effective and reliable methods of cooling remote radio heads (RRH). This paper investigates the plausibility of a passive cooling technique involving exchanging warm air, from the i...Passive cooling techniques are cost effective and reliable methods of cooling remote radio heads (RRH). This paper investigates the plausibility of a passive cooling technique involving exchanging warm air, from the internal cavity of RRHs, with fresh ambient air, to reduce the operating temperature using natural convection across air filters. The results indicate that, an internal air filter tube structure, with width of the enclosure, running vertically up the middle of an RRH, along with 4 pleat filter sides (2.0 ± 0.5 cm separation) provides the most effective outdoor suitable setup out of those examined. This provides a reduction in temperature of 3.9°K ± 0.4°K in the PA and 4.0°K ± 0.4°K in the radio, and a reduction in mass of 0.45 ± 0.05 kg, and is capable of withstanding water ingress and corrosive conditions including wind driven rain and salt fog.展开更多
BACKGROUND Esophageal stricture ranks among the most significant complications following endoscopic submucosal dissection(ESD).Excessive fibrotic repair is a typical pathological feature leading to stenosis after ESD....BACKGROUND Esophageal stricture ranks among the most significant complications following endoscopic submucosal dissection(ESD).Excessive fibrotic repair is a typical pathological feature leading to stenosis after ESD.AIM To examine the effectiveness and underlying mechanism of Kangfuxin solution(KFX)in mitigating excessive fibrotic repair of the esophagus post-ESD.METHODS Pigs received KFX at 0.74 mL/kg/d for 21 days after esophageal full circumferential ESD.Endoscopic examinations occurred on days 7 and 21 post-ESD.In vitro,recombinant transforming growth factor(TGF)-β1(5 ng/mL)induced a fibrotic microenvironment in primary esophageal fibroblasts(pEsF).After 24 hours of KFX treatment(at 1.5%,1%,and 0.5%),expression ofα-smooth muscle actin-2(ACTA2),fibronectin(FN),and type collagen I was assessed.Profibrotic signaling was analyzed,including TGF-β1,Smad2/3,and phosphor-smad2/3(p-Smad2/3).RESULTS Compared to the Control group,the groups treated with KFX and prednisolone exhibited reduced esophageal stenosis,lower weight loss rates,and improved food tolerance 21 d after ESD.After treatment,Masson staining revealed thinner and less dense collagen fibers in the submucosal layer.Additionally,the expression of fibrotic effector molecules was notably inhibited.Mechanistically,KFX downregulated the transduction levels of fibrotic functional molecules such as TGF-β1,Smad2/3,and p-Smad2/3.In vitro,pEsF exposed to TGF-β1-induced fibrotic microenvironment displayed increased fibrotic activity,which was reversed by KFX treatment,leading to reduced activation of ACTA2,FN,and collagen I.The 1.5%KFX treatment group showed decreased expression of p-Smad 2/3 in TGF-β1-activated pEsF.CONCLUSION KFX showed promise as a therapeutic option for post-full circumferential esophageal ESD strictures,potentially by suppressing fibroblast fibrotic activity through modulation of the TGF-β1/Smads signaling pathway.展开更多
Paper deals about testing of device with gravity assisted heat pipes and about researching of wick heat pipes used to effective heat transfers from power switches of energy converter. At first, to simulate ambient con...Paper deals about testing of device with gravity assisted heat pipes and about researching of wick heat pipes used to effective heat transfers from power switches of energy converter. At first, to simulate ambient condition was designed thermostatic chamber where was monitoring temperature course on main parts of cooling device （energy converter, air cooler and heat pipes） at various position of cooling device. It was found, if the cooling device is in tilt position the cooling performance is better. But if the tilt angel of gravity assisted heat pipe is higher the heat transfer is lower. From reason improve heat transfer cooling device at tilt angle are manufactured heat pipes with the sintered, mesh screen and grooved capillary structures and tested their thermal performance at vertical and tilt angel 45~ position by calorimetric method. Article describes manufacturing process and thermal performance measuring method of wick heat pipes. This experiment testify that the wick heat pipe is able operate at tilt angle position than gravity assisted heat pipe and application of wick heat pipes into cooling device will improve his cooling performance.展开更多
A detailed sensitivity study was carried out on various key parameters from a high precision numerical model of a microelectronic package cooled by natural convection, to provide rules for the thermal modeling of micr...A detailed sensitivity study was carried out on various key parameters from a high precision numerical model of a microelectronic package cooled by natural convection, to provide rules for the thermal modeling of microelectronic packages subjected to natural convection heat transfer. An accurate estimate of the junction temperature, with an error of less than 1˚C, was obtained compared to the experimental data for the vertical and horizontal orientations of the test vehicle in the JEDEC Still Air configuration. The sensitivity study showed that to have an accurate estimate of the temperature, the following elements should be present in the thermal model: radiation heat transfer in natural convection cooling;a computational fluid dynamics analysis to find realistic convection coefficients;detailed models of the high conductivity elements in the direction of the heat flow towards the environment;and finally precise values for the thicknesses of layers and the thermal properties of the substrate and the printed circuit board.展开更多
Natural products,with their remarkable structural and biological diversity,have historically served as a vital bridge between chemistry,the life sciences,and medicine.They not only provide essential scaffolds for drug...Natural products,with their remarkable structural and biological diversity,have historically served as a vital bridge between chemistry,the life sciences,and medicine.They not only provide essential scaffolds for drug discovery but also inspire innovative strategies in drug development.The biomimetic synthesis of natural products employs principles from biomimicry,applying inspiration from biogenetic processes to design synthetic strategies that mimic biosynthetic processes.Biomimetic synthesis is a highly efficient approach in synthetic chemistry,as it addresses critical challenges in the synthesis of structurally complex natural products with significant biological and medicinal importance.It has gained widespread attention from researchers in chemistry,biology,pharmacy,and related fields,underscoring its interdisciplinary impact.In this perspective,we present recent advances and challenges in the biomimetic synthesis of natural products,along with the significance and prospects of this field,highlighting the transformative potential of biomimetic synthesis strategies for both chemical and biosynthetic approaches to natural product synthesis in the pursuit of novel therapeutic agents.展开更多
Stroke is the second leading cause of disability and mortality worldwide,imposing a substantial socioeconomic burden on individuals and healthcare systems.Annually,approximately 14 million people experience stroke,wit...Stroke is the second leading cause of disability and mortality worldwide,imposing a substantial socioeconomic burden on individuals and healthcare systems.Annually,approximately 14 million people experience stroke,with ischemic stroke comprising nearly 85%of cases,of which 10%to 20%involve large vessel occlusions.Currently,recombinant tissue plasminogen activator(tPA)remains the only approved pharmacological intervention.However,its utility is limited due to a narrow therapeutic window and low recanalization rates,making it applicable to only a minority of patients.Therefore,there is an urgent need for novel therapeutic strategies,including pharmacological advancements and combinatory treatments.Small-molecule natural medicines,particularly those derived from traditional Chinese herbs,have demonstrated significant therapeutic potential in ischemic stroke management.These compounds exert multiple neuroprotective effects,such as antioxidation,anti-inflammatory action,and inhibition of apoptosis,all of which are critical in mitigating stroke-induced cerebral damage.This review comprehensively examines the pathophysiology of acute ischemic stroke(AIS)and highlights the recent progress in the development of small-molecule natural medicines as promising therapeutic agents for cerebral ischemic stroke.展开更多
Natural products(NPs)have historically been a fundamental source for drug discovery.Yet the complex nature of NPs presents substantial challenges in pinpointing bioactive constituents,and corresponding targets.In the ...Natural products(NPs)have historically been a fundamental source for drug discovery.Yet the complex nature of NPs presents substantial challenges in pinpointing bioactive constituents,and corresponding targets.In the present study,an innovative natural product virtual screening-interaction-phenotype(NP-VIP)strategy that integrates virtual screening,chemical proteomics,and metabolomics to identify and validate the bioactive targets of NPs.This approach reduces false positive results and enhances the efficiency of target identification.Salvia miltiorrhiza(SM),a herb with recognized therapeutic potential against ischemic stroke(IS),was used to illustrate the workflow.Utilizing virtual screening,chemical proteomics,and metabolomics,potential therapeutic targets for SM in the IS treatment were identified,totaling 29,100,and 78,respectively.Further analysis via the NP-VIP strategy highlighted five high-confidence targets,including poly[ADP-ribose]polymerase 1(PARP1),signal transducer and activator of transcription 3(STAT3),amyloid precursor protein(APP),glutamate-ammonia ligase(GLUL),and glutamate decarboxylase 67(GAD67).These targets were subsequently validated and found to play critical roles in the neuroprotective effects of SM.The study not only underscores the importance of SM in treating IS but also sets a precedent for NP research,proposing a comprehensive approach that could be adapted for broader pharmacological explorations.展开更多
This paper presents a high-fidelity lumpedparameter(LP)thermal model(HF-LPTM)for permanent magnet synchronous machines(PMSMs)in electric vehicle(EV)applications,where various cooling techniques are considered,includin...This paper presents a high-fidelity lumpedparameter(LP)thermal model(HF-LPTM)for permanent magnet synchronous machines(PMSMs)in electric vehicle(EV)applications,where various cooling techniques are considered,including frame forced air/liquid cooling,oil jet cooling for endwinding,and rotor shaft cooling.To address the temperature misestimation in the LP thermal modelling due to assumptions of concentrated loss input and uniform heat flows,the developed HF-LPTM introduces two compensation thermal resistances for the winding and PM components,which are analytically derived from the multi-dimensional heat transfer equations and are robust against different load/thermal conditions.As validated by the finite element analysis method and experiments,the conventional LPTMs exhibit significant winding temperature deviations,while the proposed HF-LPTM can accurately predict both the midpoint and average temperatures.The developed HFLPTM is further used to assess the effectiveness of various cooling techniques under different scenarios,i.e.,steady-state thermal states under the rated load condition,and transient temperature profiles under city,freeway,and hybrid(city+freeway)driving cycles.Results indicate that no single cooling technique can maintain both winding and PM temperatures within safety limits.The combination of frame liquid cooling and oil jet cooling for end winding can sufficiently mitigate PMSM thermal stress in EV applications.展开更多
基金funded by Fei He,National Natural Science Foundation of China(contract no.52376154)Anhui Provincial Natural Science Foundation(contract no.2308085J21).
文摘Aiming at the global design issue of transpiration cooling thermal protection system,a self-driven circulation loop is proposed as the internal coolant flow passage for the transpiration cooling structure to achieve adaptive cooling.To enhance the universality of this internal cooling pipe design and facilitate its application,numerical studies are conducted on this systemwith four commonly used cooling mediums as coolant.Firstly,the accuracy of the numerical method is verified through an established experimental platform.Then,transient numerical simulations are performed on the flow states of different cooling mediums in the new self-circulation system.Based on the numerical result,the flow,phase change,and heat transfer characteristics of different cooling mediums are analyzed.Differences in fluid velocity and latent heat of phase change result in significant variation in heat exchange capacity among different coolingmediums,with the maximumdifference reaching up to 3 times.Besides,faster circulation speed leads to greater heat transfer capacity,with a maximum of 7600 W/m^(2).Consequently,the operating mechanism and cooling laws of the natural circulation system is further investigated,providing a reference for the practical application of this system.
基金financially supported by the Science and Technology Innovation Program of Hunan Province(2024RC3003)the Central South University Innovation-Driven Research Programme(2023CXQD012)the Initiative for Sustainable Energy for its financial support。
文摘By combining the merits of radiative cooling(RC)and evaporation cooling(EC),radiative coupled evaporative cooling(REC)has attracted considerable attention for sub-ambient cooling purposes.However,for outdoor devices,the interior heating power would increase the working temperature and fire risk,which would suppress their above-ambient heat dissipation capabilities and passive water cycle properties.In this work,we introduced a REC design based on an all-in-one photonic hydrogel for above-ambient heat dissipation and flame retardancy.Unlike conventional design RC film for heat dissipation with limited cooling power and fire risk,REC hydrogel can greatly improve the heat dissipation performance in the daytime with a high workload,indicating a 12.0℃lower temperature than the RC film under the same conditions in the outdoor experiment.In the nighttime with a low workload,RC-assisted adsorption can improve atmospheric water harvesting to ensure EC in the daytime.In addition,our REC hydrogel significantly enhanced flame retardancy by absorbing heat without a corresponding temperature rise,thus mitigating fire risks.Thus,our design shows a promising solution for the thermal management of outdoor devices,delivering outstanding performance in both heat dissipation and flame retardancy.
文摘CHINA.Dinghu Mountain National Nature Reserve.Located in Zhaoqing,Guangdong Province,Dinghu Mountain National Nature Reserve is a pristine natural sanctuary spanning 1,133 hectares within the low mountain ranges of the Dayunwu Mountains.
基金support from the Contract Research(“Development of Breathable Fabrics with Nano-Electrospun Membrane”,CityU ref.:9231419“Research and application of antibacterial and healing-promoting smart nanofiber dressing for children’s burn wounds”,CityU ref:PJ9240111)+1 种基金the National Natural Science Foundation of China(“Study of Multi-Responsive Shape Memory Polyurethane Nanocomposites Inspired by Natural Fibers”,Grant No.51673162)Startup Grant of CityU(“Laboratory of Wearable Materials for Healthcare”,Grant No.9380116).
文摘Radiative cooling systems(RCSs)possess the distinctive capability to dissipate heat energy via solar and thermal radiation,making them suitable for thermal regulation and energy conservation applications,essential for mitigating the energy crisis.A comprehensive review connecting the advancements in engineered radiative cooling systems(ERCSs),encompassing material and structural design as well as thermal and energy-related applications,is currently absent.Herein,this review begins with a concise summary of the essential concepts of ERCSs,followed by an introduction to engineered materials and structures,containing nature-inspired designs,chromatic materials,meta-structural configurations,and multilayered constructions.It subsequently encapsulates the primary applications,including thermal-regulating textiles and energy-saving devices.Next,it highlights the challenges of ERCSs,including maximized thermoregulatory effects,environmental adaptability,scalability and sustainability,and interdisciplinary integration.It seeks to offer direction for forthcoming fundamental research and industrial advancement of radiative cooling systems in real-world applications.
基金supported by the Innovation and Entrepreneurship Training Program for College Students(X2025102911746,X2025102910483).
文摘Natural product(NPT)derived from traditional Chinese medicine has a rich history as an integral part of Chinese healthcare for thousands of years.Recently,the application of NPT in sonodynamic antibacterial therapy(SDAT)has emerged as a promising area of research.This perspective summarizes the recent NPT-based sonosensitizers in SDAT.Currently,common NPT-based sonosensitizers include curcumin,chlorophyll derivatives,hypericin,and berberine.Compared with other sonosensitizers,natural sources of NPT-based sonosensitizers with reactive oxide species production performance under ultrasound conditions,low biotoxicity,and other additional biological activity make them have application prospects in bacterial removal.Finally,the potential benefits and challenges of NPT-based nanosonosensitizers were also discussed.
文摘Two schemes（scheme Ⅰ and scheme Ⅱ）for designing a district cooling system（DCS）utilizing cold energy of liquefied natural gas（LNG）are presented.In scheme Ⅰ,LNG cold energy is used to produce ice,and then ice is transported to the central cooling plant of the DCS.In scheme Ⅱ,return water from the DCS is directly chilled by LNG cold energy,and the chilled water is then sent back to the central plant.The heat transportation loss is the main negative impact in the DCS and is emphatically analyzed when evaluating the efficiency of each scheme.The results show that the DCS utilizing LNG cold energy is feasible and valuable.The cooling supply distance of scheme Ⅱ is limited within 13 km while scheme Ⅰ has no distance limit.When the distance is between 6 and 13 km,scheme Ⅱ is more practical and effective.Contrarily,scheme Ⅰ has a better economic performance when the distance is shorter than 6 km or longer than 13 km.
基金The project supported by the National Natural Science Foundation of China (19725208) and the National Climbing project of China
文摘This article reports the findings on the adverse effect of the crosswind on the performance of natural draft cooling towers through numerical computation with the k-epsilon eddy-viscosity turbulence model. It is observed here that the cause of the adverse effect of the crosswind on the cooling towers call be attributed to the around flow effect which destroys the radial inflow into the cooling towers when the wind is absent. Hence, a significant deterioration in the heat transfer from the heat exchangers at lateral sides occurs.
文摘Concentrating solar thermal power system can provide low carbon,renewable energy resources in countries or regions with strong solar irradiation.For this kind of power plant which is likely to be located in the arid area,natural draft dry cooling tower is a promising choice.To develop the experimental studies on small cooling tower,a 20 m high natural draft dry cooling tower with fully instrumented measurement system was established by the Queensland Geothermal Energy Centre of Excellence.The performance of this cooling tower was measured with the constant heat input of 600 kW and 840 kW and with ambient temperature ranging from 20 ℃ to 32 ℃.The cooling tower numerical model was refined and validated with the experimental data.The model of 1 MW concentrating solar thermal supercritical CO2 power cycle was developed and integrated with the cooling tower model.The influences of changing ambient temperature and the performance of the cooling tower on efficiency of the power system were simulated.The differences of the mechanism of the ambient temperature effect on Rankine cycle and supercritical CO2 Brayton cycle were analysed and discussed.
文摘The cooling process of cooling water is veryimportant in power generation industry.The performanceof cooling towers has a great effect on security,stabilityand economy of power plants.The energy savingproblems of the cooling tower have always beenneglected previously.With the aim of energy saving inthe power plants nowadays,improving the coolingefficiency of the cooling tower has important andpractical significance.
基金Key Laboratory of Low-Grade Energy Utilization Technologies and Systems(LLEUTS-2023001)the Natural Science Foundation of Chongqing(CSTB2022NSCQ-MSX1470).
文摘This study investigates the performance of a natural draft dry cooling tower group in crosswind conditions through numerical analysis.A comprehensive three-dimensional model is developed to analyze the steady-state and dynamic behavior of the towers.The impact of wind speed and direction on heat rejection capacity and flow patterns is examined.Results indicate that crosswinds negatively affect the overall heat transfer capacity,with higher crosswind speeds leading to decreased heat transfer.Notably,wind direction plays a significant role,particularly at 0°.Moreover,tower response time increases with higher crosswind speeds due to increased turbulence and the formation of vortices.The response times are generally similar for wind directions of 45°and 90°,but differ when facing 0,where the leeward tower exhibits a shorter response time compared to the windward tower.These findings provide valuable insights into the performance of natural draft dry cooling tower groups under crosswind conditions,which can inform the design and operation of similar systems in practical applications.
文摘Large-span air-conditioning plant rooms have a large roof area and suffer from serious solar radiation in summer. The outside roof surface temperature is very high, so cooling load of roof occupies a large proportion in the envelope structure cooling load of large-span air-conditioning plant rooms. Based on the Coanda airfoil air induction unit, the author combined with exhaust air in large-span air-conditioning plant rooms to design the roof air film cooling system of large-span air-conditioning plant rooms. The adherence air film formed on the outside surface takes away heat on the outside surface of the roof, so as to reduce outside roof surface temperature of the roof, decrease heat transfer temperature difference between inside and outside roof surfaces of, and reduce roof cooling cold. Furthermore, the mathematical model and numerical simulation method of considering fluid-structure interaction for heat transfer and influences of solar radiation on air film formation of outside surface and cooling were constructed. Moreover, the numerical simulation method was conducted the validation of effectiveness. Also, the author discussed the air film formation mechanism and air film cooling ability of outside surface in large-span air-conditioning plant rooms without natural wind, developed a new air film cooling technology for the roof of large-span air-conditioning plant rooms, and supplemented the existing roof cooling technology.
文摘Different aerodynamics calculation methods for three designed cooling towers are compared. Verifications are made by using the field test data of the three operating cooling towers. It is proposed that the wind effects on water temperature after cooled by tower shall be considered in the cooling tower design; the Hamon calculation method is one of the feasible method; the method of adding the resistance coefficients of various parts of cooling tower should not be used.
文摘Passive cooling techniques are cost effective and reliable methods of cooling remote radio heads (RRH). This paper investigates the plausibility of a passive cooling technique involving exchanging warm air, from the internal cavity of RRHs, with fresh ambient air, to reduce the operating temperature using natural convection across air filters. The results indicate that, an internal air filter tube structure, with width of the enclosure, running vertically up the middle of an RRH, along with 4 pleat filter sides (2.0 ± 0.5 cm separation) provides the most effective outdoor suitable setup out of those examined. This provides a reduction in temperature of 3.9°K ± 0.4°K in the PA and 4.0°K ± 0.4°K in the radio, and a reduction in mass of 0.45 ± 0.05 kg, and is capable of withstanding water ingress and corrosive conditions including wind driven rain and salt fog.
基金Supported by Science and Technology Department of Sichuan Province,No.2020YFS0376National Natural Science Foundation of China,No.81900599Science and Technology Program of Hospital of TCM,Southwest Medical University,No.2022-CXTD-01.
文摘BACKGROUND Esophageal stricture ranks among the most significant complications following endoscopic submucosal dissection(ESD).Excessive fibrotic repair is a typical pathological feature leading to stenosis after ESD.AIM To examine the effectiveness and underlying mechanism of Kangfuxin solution(KFX)in mitigating excessive fibrotic repair of the esophagus post-ESD.METHODS Pigs received KFX at 0.74 mL/kg/d for 21 days after esophageal full circumferential ESD.Endoscopic examinations occurred on days 7 and 21 post-ESD.In vitro,recombinant transforming growth factor(TGF)-β1(5 ng/mL)induced a fibrotic microenvironment in primary esophageal fibroblasts(pEsF).After 24 hours of KFX treatment(at 1.5%,1%,and 0.5%),expression ofα-smooth muscle actin-2(ACTA2),fibronectin(FN),and type collagen I was assessed.Profibrotic signaling was analyzed,including TGF-β1,Smad2/3,and phosphor-smad2/3(p-Smad2/3).RESULTS Compared to the Control group,the groups treated with KFX and prednisolone exhibited reduced esophageal stenosis,lower weight loss rates,and improved food tolerance 21 d after ESD.After treatment,Masson staining revealed thinner and less dense collagen fibers in the submucosal layer.Additionally,the expression of fibrotic effector molecules was notably inhibited.Mechanistically,KFX downregulated the transduction levels of fibrotic functional molecules such as TGF-β1,Smad2/3,and p-Smad2/3.In vitro,pEsF exposed to TGF-β1-induced fibrotic microenvironment displayed increased fibrotic activity,which was reversed by KFX treatment,leading to reduced activation of ACTA2,FN,and collagen I.The 1.5%KFX treatment group showed decreased expression of p-Smad 2/3 in TGF-β1-activated pEsF.CONCLUSION KFX showed promise as a therapeutic option for post-full circumferential esophageal ESD strictures,potentially by suppressing fibroblast fibrotic activity through modulation of the TGF-β1/Smads signaling pathway.
文摘Paper deals about testing of device with gravity assisted heat pipes and about researching of wick heat pipes used to effective heat transfers from power switches of energy converter. At first, to simulate ambient condition was designed thermostatic chamber where was monitoring temperature course on main parts of cooling device （energy converter, air cooler and heat pipes） at various position of cooling device. It was found, if the cooling device is in tilt position the cooling performance is better. But if the tilt angel of gravity assisted heat pipe is higher the heat transfer is lower. From reason improve heat transfer cooling device at tilt angle are manufactured heat pipes with the sintered, mesh screen and grooved capillary structures and tested their thermal performance at vertical and tilt angel 45~ position by calorimetric method. Article describes manufacturing process and thermal performance measuring method of wick heat pipes. This experiment testify that the wick heat pipe is able operate at tilt angle position than gravity assisted heat pipe and application of wick heat pipes into cooling device will improve his cooling performance.
文摘A detailed sensitivity study was carried out on various key parameters from a high precision numerical model of a microelectronic package cooled by natural convection, to provide rules for the thermal modeling of microelectronic packages subjected to natural convection heat transfer. An accurate estimate of the junction temperature, with an error of less than 1˚C, was obtained compared to the experimental data for the vertical and horizontal orientations of the test vehicle in the JEDEC Still Air configuration. The sensitivity study showed that to have an accurate estimate of the temperature, the following elements should be present in the thermal model: radiation heat transfer in natural convection cooling;a computational fluid dynamics analysis to find realistic convection coefficients;detailed models of the high conductivity elements in the direction of the heat flow towards the environment;and finally precise values for the thicknesses of layers and the thermal properties of the substrate and the printed circuit board.
基金financially supported by the National Key Research and Development Program of China(2023YFC3503902)the National Natural Science Foundation of China(82430108,82293681(82293680),and 82321004)+2 种基金the Guangdong Basic and Applied Basic Research Foundation(2022B1515120015 and 2024A1515030103)the Guangdong Major Project of Basic and Applied Basic Research(2023B0303000026)the Science and Technology Projects in Guangzhou(202102070001)。
文摘Natural products,with their remarkable structural and biological diversity,have historically served as a vital bridge between chemistry,the life sciences,and medicine.They not only provide essential scaffolds for drug discovery but also inspire innovative strategies in drug development.The biomimetic synthesis of natural products employs principles from biomimicry,applying inspiration from biogenetic processes to design synthetic strategies that mimic biosynthetic processes.Biomimetic synthesis is a highly efficient approach in synthetic chemistry,as it addresses critical challenges in the synthesis of structurally complex natural products with significant biological and medicinal importance.It has gained widespread attention from researchers in chemistry,biology,pharmacy,and related fields,underscoring its interdisciplinary impact.In this perspective,we present recent advances and challenges in the biomimetic synthesis of natural products,along with the significance and prospects of this field,highlighting the transformative potential of biomimetic synthesis strategies for both chemical and biosynthetic approaches to natural product synthesis in the pursuit of novel therapeutic agents.
基金supported by the National Natural Science Foundation of China(Nos.82174010 and 81973512)。
文摘Stroke is the second leading cause of disability and mortality worldwide,imposing a substantial socioeconomic burden on individuals and healthcare systems.Annually,approximately 14 million people experience stroke,with ischemic stroke comprising nearly 85%of cases,of which 10%to 20%involve large vessel occlusions.Currently,recombinant tissue plasminogen activator(tPA)remains the only approved pharmacological intervention.However,its utility is limited due to a narrow therapeutic window and low recanalization rates,making it applicable to only a minority of patients.Therefore,there is an urgent need for novel therapeutic strategies,including pharmacological advancements and combinatory treatments.Small-molecule natural medicines,particularly those derived from traditional Chinese herbs,have demonstrated significant therapeutic potential in ischemic stroke management.These compounds exert multiple neuroprotective effects,such as antioxidation,anti-inflammatory action,and inhibition of apoptosis,all of which are critical in mitigating stroke-induced cerebral damage.This review comprehensively examines the pathophysiology of acute ischemic stroke(AIS)and highlights the recent progress in the development of small-molecule natural medicines as promising therapeutic agents for cerebral ischemic stroke.
基金supported by the National Natural Science Foundations of China(Grant No.:82204584)Liaoning Provincial Science and Technology Projects,China(Project No.:2021JH1/10400055).
文摘Natural products(NPs)have historically been a fundamental source for drug discovery.Yet the complex nature of NPs presents substantial challenges in pinpointing bioactive constituents,and corresponding targets.In the present study,an innovative natural product virtual screening-interaction-phenotype(NP-VIP)strategy that integrates virtual screening,chemical proteomics,and metabolomics to identify and validate the bioactive targets of NPs.This approach reduces false positive results and enhances the efficiency of target identification.Salvia miltiorrhiza(SM),a herb with recognized therapeutic potential against ischemic stroke(IS),was used to illustrate the workflow.Utilizing virtual screening,chemical proteomics,and metabolomics,potential therapeutic targets for SM in the IS treatment were identified,totaling 29,100,and 78,respectively.Further analysis via the NP-VIP strategy highlighted five high-confidence targets,including poly[ADP-ribose]polymerase 1(PARP1),signal transducer and activator of transcription 3(STAT3),amyloid precursor protein(APP),glutamate-ammonia ligase(GLUL),and glutamate decarboxylase 67(GAD67).These targets were subsequently validated and found to play critical roles in the neuroprotective effects of SM.The study not only underscores the importance of SM in treating IS but also sets a precedent for NP research,proposing a comprehensive approach that could be adapted for broader pharmacological explorations.
文摘This paper presents a high-fidelity lumpedparameter(LP)thermal model(HF-LPTM)for permanent magnet synchronous machines(PMSMs)in electric vehicle(EV)applications,where various cooling techniques are considered,including frame forced air/liquid cooling,oil jet cooling for endwinding,and rotor shaft cooling.To address the temperature misestimation in the LP thermal modelling due to assumptions of concentrated loss input and uniform heat flows,the developed HF-LPTM introduces two compensation thermal resistances for the winding and PM components,which are analytically derived from the multi-dimensional heat transfer equations and are robust against different load/thermal conditions.As validated by the finite element analysis method and experiments,the conventional LPTMs exhibit significant winding temperature deviations,while the proposed HF-LPTM can accurately predict both the midpoint and average temperatures.The developed HFLPTM is further used to assess the effectiveness of various cooling techniques under different scenarios,i.e.,steady-state thermal states under the rated load condition,and transient temperature profiles under city,freeway,and hybrid(city+freeway)driving cycles.Results indicate that no single cooling technique can maintain both winding and PM temperatures within safety limits.The combination of frame liquid cooling and oil jet cooling for end winding can sufficiently mitigate PMSM thermal stress in EV applications.
