Natural ventilation is an efficient design strategy for the passive cooling of buildings, especially in tropical countries such as Brazil. Among the ventilation strategies, sheds can be highlighted. These structures c...Natural ventilation is an efficient design strategy for the passive cooling of buildings, especially in tropical countries such as Brazil. Among the ventilation strategies, sheds can be highlighted. These structures consist of roof openings that work as air captors or extractors depending on their location in relation to the prevailing wind directions. The hospitals of the Sarah Network, designed by the Brazilian architect Joao Filgueiras Lima, Lele, are worldwide known for using these elements to improve natural ventilation. This paper analyses the natural ventilation performance of sheds for air collecting and extracting in two Sarah hospitals located in the cities of Salvador and Rio de Janeiro. In each building, the sheds were analyzed for air extracting and collecting. The analyses were carried out by reduced physical models in an atmospheric boundary layer wind tunnel. The wind velocity was measured at external and internal points of the buildings, using hot-wire anemometers. The results show that the wards in Rio de Janeiro hospital are 17% more ventilated than the ones in the Salvador hospital. However, this difference occurs not only because of the collecting sheds but also because of set of openings and the configuration of the covering in hospitals in Rio de Janeiro.展开更多
The rivalry between T cells and tumor cells somewhat mimics the scene of 'Tom and Jerry,' an animated series in which Tom (a house cat) rarely succeeds in catching Jerry (a mouse), mainly because of Jerry’s c...The rivalry between T cells and tumor cells somewhat mimics the scene of 'Tom and Jerry,' an animated series in which Tom (a house cat) rarely succeeds in catching Jerry (a mouse), mainly because of Jerry’s cleverness and cunning abilities. In a way, tumor cells are like Jerry, in terms of their crafty and sneaky features.展开更多
EDITOR＇S NOTE： As the widening gap between the rich and poor has become a major byproduct of China＇s nonstop economic growth over the past decades, the improvement of the disadvantaged group＇s livelihood has becom...EDITOR＇S NOTE： As the widening gap between the rich and poor has become a major byproduct of China＇s nonstop economic growth over the past decades, the improvement of the disadvantaged group＇s livelihood has become a top government concern. While numerous cities are working out their plans for ＂livelihood improvement projects,＂ local governments are making efforts to establish a sustainable mechanism that provides prompt, adequate relief to the needy. Licheng District in Jinan, capital of Shandong province, sets an example.展开更多
Rock sheds are widely used to prevent rockfall disasters along roads in mountainous areas.To improve the capacity of rock sheds for resisting rockfall impact,a sand and expandable polyethylene(EPE)composite cushion wa...Rock sheds are widely used to prevent rockfall disasters along roads in mountainous areas.To improve the capacity of rock sheds for resisting rockfall impact,a sand and expandable polyethylene(EPE)composite cushion was proposed.A series of model experiments of rockfall impact on rock sheds were conducted,and the buried depth of the EPE foam board in the sand layer was considered.The impact load and dynamic response of the rock shed were investigated.The results show that the maximum impact load and dynamic response of the rock shed roof are all significantly less than those of the sand cushion.Moreover,as the distance between the EPE foam board and rock shed roof decreases,the maximum rockfall impact force and impact pressure gradually decrease,and the maximum displacement,acceleration and strain of the rock shed first decrease and then change little.In addition,the vibration acceleration and vertical displacement of the rock shed roof decrease from the centre to the edge and decrease faster along the longitudinal direction than that along the transverse direction.In conclusion,the buffering effect of the sand-EPE composite cushion is better than that of the pure sand cushion,and the EPE foam board at a depth of 1/3 the thickness of the sand layer is appropriate.展开更多
Sn-based batteries have emerged as an optimal energy storage system owing to their abundant Sn resources,environmental compatibility,non-toxicity,corrosion resistance,and high hydrogen evolution overpotential.However,...Sn-based batteries have emerged as an optimal energy storage system owing to their abundant Sn resources,environmental compatibility,non-toxicity,corrosion resistance,and high hydrogen evolution overpotential.However,the practical application of these batteries is hindered by challenges such as“dead Sn”shedding and hydrogen evolution side reactions.Extensive research has focused on improving the performance of Sn-based batteries.This paper provides a comprehensive review of the recent advancements in Sn-based battery research,including the selection of current collectors,electrolyte optimization,and the development of new cathode materials.The energy storage mechanisms and challenges of Sn-based batteries are discussed.Overall,this paper presents future perspectives of high-performance rechargeable Sn-based batteries and provides valuable guidance for developing Sn-based energy storage technologies.展开更多
The debate over how one of the most popular osteoarthritis treatments should be federally regulated could change,thanks to a Cornell University study and a new device that provides a better understanding of the scienc...The debate over how one of the most popular osteoarthritis treatments should be federally regulated could change,thanks to a Cornell University study and a new device that provides a better understanding of the science behind hyaluronic acid(HA)injections.展开更多
On August 9,Shandong became the first province in China to abolish performance evaluations based on the number of prosecutions and'cases solved'by police departments.Although the move is ostensibly intended to...On August 9,Shandong became the first province in China to abolish performance evaluations based on the number of prosecutions and'cases solved'by police departments.Although the move is ostensibly intended to'redirect energy to public security,crime-prevention,and public assistance,'some lawyers hope it could also improve the'objectivity'of law enforcement in a country where police and prosecutors almost never fail to win in court.展开更多
PrPSc,a misfolded,aggregation-prone isoform of the cellular prion protein(PrPC),is the infectious prion agent responsible for fatal neurodegenerative diseases of humans and other mammals.PrPSccan adopt different patho...PrPSc,a misfolded,aggregation-prone isoform of the cellular prion protein(PrPC),is the infectious prion agent responsible for fatal neurodegenerative diseases of humans and other mammals.PrPSccan adopt different pathogenic conformations(prion strains),which can be resistant to potential drugs,or acquire drug resistance,posing challenges for the development of effective therapies.Since PrPCis the obligate precursor of any prion strain and serves as the mediator of prion neurotoxicity,it represents an attractive therapeutic target fo r prion diseases.In this minireview,we briefly outline the approaches to target PrPCand discuss our recent identification of Zn(Ⅱ)-Bn PyP,a PrPC-targeting porphyrin with an unprecedented bimodal mechanism of action.We argue that in-depth understanding of the molecular mechanism by which Zn(Ⅱ)-Bn PyP targets PrPCmay lead toward the development of a new class of dual mechanism anti-prion compounds.展开更多
Jiangsu Niupai Machinery&Elecronics Co,ltd.is National Specialized and New"Little Giant"Enterprise,National High&New Technological Enterprise,Jiangsu Provincial Research Center of Loom Shedding Engin...Jiangsu Niupai Machinery&Elecronics Co,ltd.is National Specialized and New"Little Giant"Enterprise,National High&New Technological Enterprise,Jiangsu Provincial Research Center of Loom Shedding Engineering Technology and Jiangsu Provincial Enterprise Technology Center.The company has obtained SGS-certified ISO9001 quality management system,a globally recognized standard.Niupai specializes in the R&D and manufacturing of cam shedding device,dobby shedding device,jacquard shedding device and heald frames for water-jet looms,air-jet looms as well as rapier looms.展开更多
Changshu Textile Machinery Works Co.,Ltd.was founded in 1958 and is a professional R&D and manufacturing enterprise of looms shedding device in China.The company's products cover three series of shedding devic...Changshu Textile Machinery Works Co.,Ltd.was founded in 1958 and is a professional R&D and manufacturing enterprise of looms shedding device in China.The company's products cover three series of shedding devices for looms(Dobby,Jacquard,Cam Motion),forming a series of products with electronic shedding devices as the main products,and mechanical shedding devices as the auxiliary products.D2876pro electronic dobby The D2876pro electronic dobby is a high-performance equipment designed for a maximum operating speed of 800rpm.It has 16 cams,and 12mm of pitch,with a high installation type.The shedding type is double lift and full clear open.Its maximum wefts is 12,800 and 100,000.It has a two-stage filtration lubrication with a gerotor pump oil recycle system,and it is suitable for water-jet looms.展开更多
A robust Reynolds-Averaged Navier-Stokes(RANS)based solver is established to predict the complex unsteady aerodynamic characteristics of the Active Flap Control(AFC)rotor.The complex motion with multiple degrees of fr...A robust Reynolds-Averaged Navier-Stokes(RANS)based solver is established to predict the complex unsteady aerodynamic characteristics of the Active Flap Control(AFC)rotor.The complex motion with multiple degrees of freedom of the Trailing Edge Flap(TEF)is analyzed by employing an inverse nested overset grid method.Simulation of non-rotational and rotational modes of blade motion are carried out to investigate the formation and development of TEF shedding vortex with high-frequency deflection of TEF.Moreover,the mechanism of TEF deflection interference with blade tip vortex and overall rotor aerodynamics is also explored.In nonrotational mode,two bundles of vortices form at the gap ends of TEF and the main blade and merge into a single TEF vortex.Dynamic deflection of the TEF significantly interferes with the blade tip vortex.The position of the blade tip vortex consistently changes,and its frequency is directly related to the frequency of TEF deflection.In rotational mode,the tip vortex forms a helical structure.The end vortices at the gap sides co-swirl and subsequently merge into the concentrated beam of tip vortices,causing fluctuations in the vorticity and axial position of the tip vortex under the rotor.This research concludes with the investigation on suppression of Blade Vortex Interaction(BVI),showing an increase in miss distance and reduction in the vorticity of tip vortex through TEF phase control at a particular control frequency.Through this mechanism,a designed TEF deflection law increases the miss distance by 34.7%and reduces vorticity by 11.9%at the target position,demonstrating the effectiveness of AFC in mitigating BVI.展开更多
Pulsating flow is a common condition for under water manipulators in Bohai Bay.This study aimed to investigate the effects of pulsation frequency and amplitude on the hydrodynamic characteristics of an underwater mani...Pulsating flow is a common condition for under water manipulators in Bohai Bay.This study aimed to investigate the effects of pulsation frequency and amplitude on the hydrodynamic characteristics of an underwater manipulator with different postures using the user-defined function (UDF) method. The lift coefficient (C_(L)), drag coefficient (C_(D)), and vortex shedding of the underwater manipulator in single-and dualarm forms were obtained. Results indicated that the maximum increase in the lift and drag coefficients subjected to the pulsation parameters was 24.45%and 28%, respectively, when the fluid flowed past a single arm. Compared with the single arm, the lift and drag coefficients of the arms were higher than those of the single arm when arm 2 was located upstream. Additionally, the pulsation frequency had no obvious effect on the manipulator, but the C_(L) and C_(D) of arm 2 showed an obvious increasing trend with an increase in pulsation amplitude. Meanwhile, when arm 2 was located downstream, the C_(L) and C_(D) of arm 2 were reduced by 16.38%and 1.15%, respectively, with an increase in the pulse frequency,and the maximum increase in the lift and dragcoefficients was 33.33%and 16.78%,respectively,with increasing pulsation amplitude.Moreover, the downstream wake morphology changed significantly, and a combined vortex phenomenon appeared. Finally, a theoretical basis for examining the hydrodynamic characteristics of marine engineering equipment was established to aid future marine resource exploitation.展开更多
The electro⁃thermal anti/de-icing systems have high heating efficiency and relatively simple structures,marking them as a key development direction for future icing protection.Existing simulation algorithms for electr...The electro⁃thermal anti/de-icing systems have high heating efficiency and relatively simple structures,marking them as a key development direction for future icing protection.Existing simulation algorithms for electrothermal de-icing seldom delve into comprehensive ice accretion-melting-deicing models that account for ice shedding.Therefore,the detachment behavior of ice layers during the heating process requires in-depth research and discussion.This paper physically models the phenomenon of ice shedding,incorporates the detachment behavior of ice layers during heating,improves the existing mathematical model for electro-thermal de-icing calculations,establishes an ice accretion-melting-deicing model for electro-thermal de-icing systems,and conducts numerical simulation,verification and optimization analysis of electro-thermal de-icing considering ice shedding.Through multi-condition de-icing numerical simulations of a specific wing model,it is found that ambient temperature can serve as a factor for adapting the electro heating anti/de-icing strategy to the environment.An optimization of heating heat flux density and heating/cooling time is conducted for the wing de-icing control law under the calculated conditions.The improved electrothermal de-icing model and algorithm developed in this paper provide solid technical support for the design of electrothermal de-icing systems.展开更多
The cavitation tunnel with controlled background pressure is a pivotal experimental setup for studying the mechanisms of cavitating flows and hydrodynamic loads on cavitating bodies.Existing recirculating cavitation t...The cavitation tunnel with controlled background pressure is a pivotal experimental setup for studying the mechanisms of cavitating flows and hydrodynamic loads on cavitating bodies.Existing recirculating cavitation tunnels predominantly feature horizontal test sections for modeling cavity flows in horizontal incoming flow and vertical gravitational acceleration and fail to meet the requirements for long-duration experiments on ventilated cavity flows.This paper introduces the unique gravitydriven vertical water tunnel(GVWT),facilitating hydrodynamic experiments on axisymmetric slender bodies with ventilated cavities in the streamwise gravitational acceleration.It elaborates high-throughput data processing method for synchronously measured high-speed camera images of cavity forms and pressure distribution from sensor arrays on model surfaces in unsteady long-duration ventilation conditions.For the ventilated cavity flow against an axisymmetric slender body with 60°cone headform at zero angle of attack,the developed partial cavity can be divided into four regimes:The sheet cavity,the combined sheet and cloud cavity,the entire cloud cavity,and the shedding cloud cavity.The mean cavity length and thickness are well-defined by the high-speed images.For the unsteady ventilated cavity due to the re-entrant jet,the Strouhal number based on cavity length and pulsation frequency of the cloud cavity equals 0.276.The mean pressure distribution in the ventilated cavity reveals a difference between the pressure within the sheet cavity and the maximum pressure in the cavity closure,which is influenced by the streamwise gravitational effect.The experimental results demonstrate that GVWT provides a novel experimental approach for understanding the physics of ventilated cavity evolution and bubbly flows under the effect of the streamwise gravitational acceleration.展开更多
1 In a world filled with more“stuff”than we need,sharing libraries are emerging as a solution to both environmental and economic concerns.Unlike traditional libraries,these“libraries of things”offer a variety of i...1 In a world filled with more“stuff”than we need,sharing libraries are emerging as a solution to both environmental and economic concerns.Unlike traditional libraries,these“libraries of things”offer a variety of items for borrowing,often for free or at a low cost.2 For example,the Oxford Maternity Clothes Library provides expectant mothers with free maternity wear,while the Warwick Toy Library allows locals to borrow toys and even reserve them online.The Tool Library in Wolverhampton offers gardening and DIY equipment,and the Share Shed in Devon has over 350 items available.Nappy libraries also provide parents with reusable cloth nappies(尿布),reducing costs and waste.展开更多
目的:观察乳牙牙髓干细胞(SHEDs)在3种羟基磷灰石(HA)复合支架材料上黏附、增殖、分化情况。方法:利用正常替换的乳牙分离培养SHEDs,免疫组织化学法鉴定细胞来源,体外诱导实验观察细胞分化能力。将SHEDs分别接种在羟基磷灰石/β-磷酸三...目的:观察乳牙牙髓干细胞(SHEDs)在3种羟基磷灰石(HA)复合支架材料上黏附、增殖、分化情况。方法:利用正常替换的乳牙分离培养SHEDs,免疫组织化学法鉴定细胞来源,体外诱导实验观察细胞分化能力。将SHEDs分别接种在羟基磷灰石/β-磷酸三钙(HA/TCP),羟基磷灰石/胶原(HA/COL)和羟基磷灰石/聚乙丙交酯(HA/PLGA)支架材料上复合培养,于4、6、8、10 h 4个时间点检测各细胞黏附率,MTT比色法检测SHEDs增殖情况;碱性磷酸酶(ALP)活性检测、能谱分析钙含量;Von Kossa染色和灰度扫描细胞矿化能力。结果:SHEDs在HA/COL上的黏附少于HA/PLGA和HA/TCP(P<0.05);HA/PLGA对SHEDs矿化诱导能力最强,其次是HA/TCP,HA/COL最弱。结论:SHEDs在HA/PLGA上的黏附率、增殖率及矿化能力优于HA/TCP和HA/COL。展开更多
目的:评估iRoot BP Plus和ProRoot MTA作为盖髓剂对脱落乳牙牙髓干细胞(stem cells from human exfoliated deciduous teeth,SHED)和人牙髓干细胞(human dental pulp stem cells,DPSC)生物学行为的影响.方法:选择处于生理性牙根吸收期...目的:评估iRoot BP Plus和ProRoot MTA作为盖髓剂对脱落乳牙牙髓干细胞(stem cells from human exfoliated deciduous teeth,SHED)和人牙髓干细胞(human dental pulp stem cells,DPSC)生物学行为的影响.方法:选择处于生理性牙根吸收期的乳牙和无龋的正畸减数前磨牙或第三磨牙,体外提取、分离和培养SHED和DPSC,制备iRoot BP Plus和ProRoot MTA标准膜片并提取浸提液,通过CCK-8法检测l、3、5、7d时iRoot BP Plus和MTA浸提液对SHED和DPSC增殖能力的影响;Transwell小室和划痕修复实验观察iRoot BP Plus和MTA浸提液对SHED和DPSC迁移能力的影响;SHED和DPSC分别接种于iRoot BP Plus和MTA样品表面进行培养,分别在1、3、5d使用鬼笔环肽(phalloidin)和DAPI(4',6-diamidino-2-phenylindole)进行免疫荧光染色,观察细胞骨架变化;SHED和DPSC分别在成骨诱导培养基、含MTA浸提液的成骨诱导培养基和含iRoot BP Plus浸提液的成骨诱导培养基中进行矿化诱导,7d和14d时进行碱性磷酸酶(alkaline phosphatase,ALP)染色以及ALP定量分析,21 d时进行茜素红染色和半定量分析钙盐沉积量,采用SPSS 19.0软件包对数据进行统计学分析.结果:iRoot BP Plus和MTA均能促进SHED和DPSC的细胞增殖;细胞迁移与黏附实验中,iRoot BP Plus和MTA均能促进SHED和DPSC的迁移与黏附,其中,iRoot BP Plus的作用更显著(p=0.000);经矿化诱导后,iRoot BP Plus组的SHED和DPSC的ALP活性强于MTA组,茜素红染色和半定量分析钙盐沉积量结果显示,iRoot BP Plus和MTA均能促进细胞矿化,且iRoot BP Plus促进细胞矿化的能力显著强于MTA (P=0.000).结论:iRoot BP Plus和MTA均具有较好的生物相容性,均能促进SHED和DPSC的细胞增殖,能够促进细胞黏附、迁移,具有较好的成骨分化能力;且iRoot BP Plus促进SHED和DPSC黏附、迁移和成骨分化的能力相对MTA更好,iRoot BP Plus和MTA均可作为乳牙和年轻恒牙牙髓治疗的盖髓剂.展开更多
文摘Natural ventilation is an efficient design strategy for the passive cooling of buildings, especially in tropical countries such as Brazil. Among the ventilation strategies, sheds can be highlighted. These structures consist of roof openings that work as air captors or extractors depending on their location in relation to the prevailing wind directions. The hospitals of the Sarah Network, designed by the Brazilian architect Joao Filgueiras Lima, Lele, are worldwide known for using these elements to improve natural ventilation. This paper analyses the natural ventilation performance of sheds for air collecting and extracting in two Sarah hospitals located in the cities of Salvador and Rio de Janeiro. In each building, the sheds were analyzed for air extracting and collecting. The analyses were carried out by reduced physical models in an atmospheric boundary layer wind tunnel. The wind velocity was measured at external and internal points of the buildings, using hot-wire anemometers. The results show that the wards in Rio de Janeiro hospital are 17% more ventilated than the ones in the Salvador hospital. However, this difference occurs not only because of the collecting sheds but also because of set of openings and the configuration of the covering in hospitals in Rio de Janeiro.
文摘The rivalry between T cells and tumor cells somewhat mimics the scene of 'Tom and Jerry,' an animated series in which Tom (a house cat) rarely succeeds in catching Jerry (a mouse), mainly because of Jerry’s cleverness and cunning abilities. In a way, tumor cells are like Jerry, in terms of their crafty and sneaky features.
文摘EDITOR＇S NOTE： As the widening gap between the rich and poor has become a major byproduct of China＇s nonstop economic growth over the past decades, the improvement of the disadvantaged group＇s livelihood has become a top government concern. While numerous cities are working out their plans for ＂livelihood improvement projects,＂ local governments are making efforts to establish a sustainable mechanism that provides prompt, adequate relief to the needy. Licheng District in Jinan, capital of Shandong province, sets an example.
基金supported by the Natural Science Foundation of Sichuan Province(No.2022NSFSC1127)the Fundamental Research Funds for the Central Universities(No.2682023CX075).
文摘Rock sheds are widely used to prevent rockfall disasters along roads in mountainous areas.To improve the capacity of rock sheds for resisting rockfall impact,a sand and expandable polyethylene(EPE)composite cushion was proposed.A series of model experiments of rockfall impact on rock sheds were conducted,and the buried depth of the EPE foam board in the sand layer was considered.The impact load and dynamic response of the rock shed were investigated.The results show that the maximum impact load and dynamic response of the rock shed roof are all significantly less than those of the sand cushion.Moreover,as the distance between the EPE foam board and rock shed roof decreases,the maximum rockfall impact force and impact pressure gradually decrease,and the maximum displacement,acceleration and strain of the rock shed first decrease and then change little.In addition,the vibration acceleration and vertical displacement of the rock shed roof decrease from the centre to the edge and decrease faster along the longitudinal direction than that along the transverse direction.In conclusion,the buffering effect of the sand-EPE composite cushion is better than that of the pure sand cushion,and the EPE foam board at a depth of 1/3 the thickness of the sand layer is appropriate.
基金supported by the National Natural Science Foundation of China(No.62464010)the Spring City Plan-Special Program for Young Talents(K202005007)+2 种基金the Yunnan Talents Support Plan for Young Talents(XDYC-QNRC-2022-0482)the Yunnan Local Colleges Applied Basic Research Projects(202101BA070001-138)the Key Laboratory of Artificial Microstructures in Yunnan Higher Education,and the Frontier Research Team of Kunming University 2023.
文摘Sn-based batteries have emerged as an optimal energy storage system owing to their abundant Sn resources,environmental compatibility,non-toxicity,corrosion resistance,and high hydrogen evolution overpotential.However,the practical application of these batteries is hindered by challenges such as“dead Sn”shedding and hydrogen evolution side reactions.Extensive research has focused on improving the performance of Sn-based batteries.This paper provides a comprehensive review of the recent advancements in Sn-based battery research,including the selection of current collectors,electrolyte optimization,and the development of new cathode materials.The energy storage mechanisms and challenges of Sn-based batteries are discussed.Overall,this paper presents future perspectives of high-performance rechargeable Sn-based batteries and provides valuable guidance for developing Sn-based energy storage technologies.
文摘The debate over how one of the most popular osteoarthritis treatments should be federally regulated could change,thanks to a Cornell University study and a new device that provides a better understanding of the science behind hyaluronic acid(HA)injections.
文摘On August 9,Shandong became the first province in China to abolish performance evaluations based on the number of prosecutions and'cases solved'by police departments.Although the move is ostensibly intended to'redirect energy to public security,crime-prevention,and public assistance,'some lawyers hope it could also improve the'objectivity'of law enforcement in a country where police and prosecutors almost never fail to win in court.
基金supported by Telethon Italy award GGP15225(to RC and GM)Italian Ministry of Health award RF-2016-02362950(to RC and CZ)+1 种基金the CJD Foundation USA(to RC)the Associazione Italiana Encefalopatie da Prioni(AIEnP)(to RC).
文摘PrPSc,a misfolded,aggregation-prone isoform of the cellular prion protein(PrPC),is the infectious prion agent responsible for fatal neurodegenerative diseases of humans and other mammals.PrPSccan adopt different pathogenic conformations(prion strains),which can be resistant to potential drugs,or acquire drug resistance,posing challenges for the development of effective therapies.Since PrPCis the obligate precursor of any prion strain and serves as the mediator of prion neurotoxicity,it represents an attractive therapeutic target fo r prion diseases.In this minireview,we briefly outline the approaches to target PrPCand discuss our recent identification of Zn(Ⅱ)-Bn PyP,a PrPC-targeting porphyrin with an unprecedented bimodal mechanism of action.We argue that in-depth understanding of the molecular mechanism by which Zn(Ⅱ)-Bn PyP targets PrPCmay lead toward the development of a new class of dual mechanism anti-prion compounds.
文摘Jiangsu Niupai Machinery&Elecronics Co,ltd.is National Specialized and New"Little Giant"Enterprise,National High&New Technological Enterprise,Jiangsu Provincial Research Center of Loom Shedding Engineering Technology and Jiangsu Provincial Enterprise Technology Center.The company has obtained SGS-certified ISO9001 quality management system,a globally recognized standard.Niupai specializes in the R&D and manufacturing of cam shedding device,dobby shedding device,jacquard shedding device and heald frames for water-jet looms,air-jet looms as well as rapier looms.
文摘Changshu Textile Machinery Works Co.,Ltd.was founded in 1958 and is a professional R&D and manufacturing enterprise of looms shedding device in China.The company's products cover three series of shedding devices for looms(Dobby,Jacquard,Cam Motion),forming a series of products with electronic shedding devices as the main products,and mechanical shedding devices as the auxiliary products.D2876pro electronic dobby The D2876pro electronic dobby is a high-performance equipment designed for a maximum operating speed of 800rpm.It has 16 cams,and 12mm of pitch,with a high installation type.The shedding type is double lift and full clear open.Its maximum wefts is 12,800 and 100,000.It has a two-stage filtration lubrication with a gerotor pump oil recycle system,and it is suitable for water-jet looms.
基金supported by the National Natural Science Foundation of China(No.11972190)。
文摘A robust Reynolds-Averaged Navier-Stokes(RANS)based solver is established to predict the complex unsteady aerodynamic characteristics of the Active Flap Control(AFC)rotor.The complex motion with multiple degrees of freedom of the Trailing Edge Flap(TEF)is analyzed by employing an inverse nested overset grid method.Simulation of non-rotational and rotational modes of blade motion are carried out to investigate the formation and development of TEF shedding vortex with high-frequency deflection of TEF.Moreover,the mechanism of TEF deflection interference with blade tip vortex and overall rotor aerodynamics is also explored.In nonrotational mode,two bundles of vortices form at the gap ends of TEF and the main blade and merge into a single TEF vortex.Dynamic deflection of the TEF significantly interferes with the blade tip vortex.The position of the blade tip vortex consistently changes,and its frequency is directly related to the frequency of TEF deflection.In rotational mode,the tip vortex forms a helical structure.The end vortices at the gap sides co-swirl and subsequently merge into the concentrated beam of tip vortices,causing fluctuations in the vorticity and axial position of the tip vortex under the rotor.This research concludes with the investigation on suppression of Blade Vortex Interaction(BVI),showing an increase in miss distance and reduction in the vorticity of tip vortex through TEF phase control at a particular control frequency.Through this mechanism,a designed TEF deflection law increases the miss distance by 34.7%and reduces vorticity by 11.9%at the target position,demonstrating the effectiveness of AFC in mitigating BVI.
基金the National Natural Science Foundation of China (No. 51905211)China Postdoctoral Science Foundation (Grant No. 2020M672128)+1 种基金University of Jinan Research Startup and Discipline Construction Fund (Grant No.1009435)a Project of the “20 Regulations for New Universities” funding program of Jinan (No.202228116)。
文摘Pulsating flow is a common condition for under water manipulators in Bohai Bay.This study aimed to investigate the effects of pulsation frequency and amplitude on the hydrodynamic characteristics of an underwater manipulator with different postures using the user-defined function (UDF) method. The lift coefficient (C_(L)), drag coefficient (C_(D)), and vortex shedding of the underwater manipulator in single-and dualarm forms were obtained. Results indicated that the maximum increase in the lift and drag coefficients subjected to the pulsation parameters was 24.45%and 28%, respectively, when the fluid flowed past a single arm. Compared with the single arm, the lift and drag coefficients of the arms were higher than those of the single arm when arm 2 was located upstream. Additionally, the pulsation frequency had no obvious effect on the manipulator, but the C_(L) and C_(D) of arm 2 showed an obvious increasing trend with an increase in pulsation amplitude. Meanwhile, when arm 2 was located downstream, the C_(L) and C_(D) of arm 2 were reduced by 16.38%and 1.15%, respectively, with an increase in the pulse frequency,and the maximum increase in the lift and dragcoefficients was 33.33%and 16.78%,respectively,with increasing pulsation amplitude.Moreover, the downstream wake morphology changed significantly, and a combined vortex phenomenon appeared. Finally, a theoretical basis for examining the hydrodynamic characteristics of marine engineering equipment was established to aid future marine resource exploitation.
基金supported by the National Natural Science Foundation of China(No.52272428)。
文摘The electro⁃thermal anti/de-icing systems have high heating efficiency and relatively simple structures,marking them as a key development direction for future icing protection.Existing simulation algorithms for electrothermal de-icing seldom delve into comprehensive ice accretion-melting-deicing models that account for ice shedding.Therefore,the detachment behavior of ice layers during the heating process requires in-depth research and discussion.This paper physically models the phenomenon of ice shedding,incorporates the detachment behavior of ice layers during heating,improves the existing mathematical model for electro-thermal de-icing calculations,establishes an ice accretion-melting-deicing model for electro-thermal de-icing systems,and conducts numerical simulation,verification and optimization analysis of electro-thermal de-icing considering ice shedding.Through multi-condition de-icing numerical simulations of a specific wing model,it is found that ambient temperature can serve as a factor for adapting the electro heating anti/de-icing strategy to the environment.An optimization of heating heat flux density and heating/cooling time is conducted for the wing de-icing control law under the calculated conditions.The improved electrothermal de-icing model and algorithm developed in this paper provide solid technical support for the design of electrothermal de-icing systems.
基金supported by the National Natural Science Foundation of China(Grant No.12102262)CST Foundation of China Academy of Launch Vehicle Technology.
文摘The cavitation tunnel with controlled background pressure is a pivotal experimental setup for studying the mechanisms of cavitating flows and hydrodynamic loads on cavitating bodies.Existing recirculating cavitation tunnels predominantly feature horizontal test sections for modeling cavity flows in horizontal incoming flow and vertical gravitational acceleration and fail to meet the requirements for long-duration experiments on ventilated cavity flows.This paper introduces the unique gravitydriven vertical water tunnel(GVWT),facilitating hydrodynamic experiments on axisymmetric slender bodies with ventilated cavities in the streamwise gravitational acceleration.It elaborates high-throughput data processing method for synchronously measured high-speed camera images of cavity forms and pressure distribution from sensor arrays on model surfaces in unsteady long-duration ventilation conditions.For the ventilated cavity flow against an axisymmetric slender body with 60°cone headform at zero angle of attack,the developed partial cavity can be divided into four regimes:The sheet cavity,the combined sheet and cloud cavity,the entire cloud cavity,and the shedding cloud cavity.The mean cavity length and thickness are well-defined by the high-speed images.For the unsteady ventilated cavity due to the re-entrant jet,the Strouhal number based on cavity length and pulsation frequency of the cloud cavity equals 0.276.The mean pressure distribution in the ventilated cavity reveals a difference between the pressure within the sheet cavity and the maximum pressure in the cavity closure,which is influenced by the streamwise gravitational effect.The experimental results demonstrate that GVWT provides a novel experimental approach for understanding the physics of ventilated cavity evolution and bubbly flows under the effect of the streamwise gravitational acceleration.
文摘1 In a world filled with more“stuff”than we need,sharing libraries are emerging as a solution to both environmental and economic concerns.Unlike traditional libraries,these“libraries of things”offer a variety of items for borrowing,often for free or at a low cost.2 For example,the Oxford Maternity Clothes Library provides expectant mothers with free maternity wear,while the Warwick Toy Library allows locals to borrow toys and even reserve them online.The Tool Library in Wolverhampton offers gardening and DIY equipment,and the Share Shed in Devon has over 350 items available.Nappy libraries also provide parents with reusable cloth nappies(尿布),reducing costs and waste.
文摘目的:观察乳牙牙髓干细胞(SHEDs)在3种羟基磷灰石(HA)复合支架材料上黏附、增殖、分化情况。方法:利用正常替换的乳牙分离培养SHEDs,免疫组织化学法鉴定细胞来源,体外诱导实验观察细胞分化能力。将SHEDs分别接种在羟基磷灰石/β-磷酸三钙(HA/TCP),羟基磷灰石/胶原(HA/COL)和羟基磷灰石/聚乙丙交酯(HA/PLGA)支架材料上复合培养,于4、6、8、10 h 4个时间点检测各细胞黏附率,MTT比色法检测SHEDs增殖情况;碱性磷酸酶(ALP)活性检测、能谱分析钙含量;Von Kossa染色和灰度扫描细胞矿化能力。结果:SHEDs在HA/COL上的黏附少于HA/PLGA和HA/TCP(P<0.05);HA/PLGA对SHEDs矿化诱导能力最强,其次是HA/TCP,HA/COL最弱。结论:SHEDs在HA/PLGA上的黏附率、增殖率及矿化能力优于HA/TCP和HA/COL。
文摘目的:评估iRoot BP Plus和ProRoot MTA作为盖髓剂对脱落乳牙牙髓干细胞(stem cells from human exfoliated deciduous teeth,SHED)和人牙髓干细胞(human dental pulp stem cells,DPSC)生物学行为的影响.方法:选择处于生理性牙根吸收期的乳牙和无龋的正畸减数前磨牙或第三磨牙,体外提取、分离和培养SHED和DPSC,制备iRoot BP Plus和ProRoot MTA标准膜片并提取浸提液,通过CCK-8法检测l、3、5、7d时iRoot BP Plus和MTA浸提液对SHED和DPSC增殖能力的影响;Transwell小室和划痕修复实验观察iRoot BP Plus和MTA浸提液对SHED和DPSC迁移能力的影响;SHED和DPSC分别接种于iRoot BP Plus和MTA样品表面进行培养,分别在1、3、5d使用鬼笔环肽(phalloidin)和DAPI(4',6-diamidino-2-phenylindole)进行免疫荧光染色,观察细胞骨架变化;SHED和DPSC分别在成骨诱导培养基、含MTA浸提液的成骨诱导培养基和含iRoot BP Plus浸提液的成骨诱导培养基中进行矿化诱导,7d和14d时进行碱性磷酸酶(alkaline phosphatase,ALP)染色以及ALP定量分析,21 d时进行茜素红染色和半定量分析钙盐沉积量,采用SPSS 19.0软件包对数据进行统计学分析.结果:iRoot BP Plus和MTA均能促进SHED和DPSC的细胞增殖;细胞迁移与黏附实验中,iRoot BP Plus和MTA均能促进SHED和DPSC的迁移与黏附,其中,iRoot BP Plus的作用更显著(p=0.000);经矿化诱导后,iRoot BP Plus组的SHED和DPSC的ALP活性强于MTA组,茜素红染色和半定量分析钙盐沉积量结果显示,iRoot BP Plus和MTA均能促进细胞矿化,且iRoot BP Plus促进细胞矿化的能力显著强于MTA (P=0.000).结论:iRoot BP Plus和MTA均具有较好的生物相容性,均能促进SHED和DPSC的细胞增殖,能够促进细胞黏附、迁移,具有较好的成骨分化能力;且iRoot BP Plus促进SHED和DPSC黏附、迁移和成骨分化的能力相对MTA更好,iRoot BP Plus和MTA均可作为乳牙和年轻恒牙牙髓治疗的盖髓剂.
