Edible bird’s nest (EBN;Yan Wo), or cubilose, is originated from the salivary secretion of Aerodramus fuciphagus. In Asia, EBN is famous for its unproven skin lightening function. Here, we aim to reveal the active in...Edible bird’s nest (EBN;Yan Wo), or cubilose, is originated from the salivary secretion of Aerodramus fuciphagus. In Asia, EBN is famous for its unproven skin lightening function. Here, we aim to reveal the active ingredients of EBN responsible for skin lightening function. Three major fractions were isolated from EBN water extract by chromatography using LC-MS/MS, bioactivities of these isolated fractions were analyzed by assays of tyrosinase, melanocytes and 3D human skin model, from which, N-acetylneuraminic acid (NANA), the second isolated fraction showed an inhibition effect on tyrosinase activity in a dose-dependent manner. The IC50 of tyrosinase originated from mushroom and human was 16.93 mM and 0.10 mM respectively. Furthermore, only EBN with higher content of NANA (e.g. White and Red EBN), but not EBN with less NANA (e.g. Grass EBN), showed promising skin lightening function. This is the first report to reveal NANA being an active ingredient of EBN on skin lightening function.展开更多
TiO2 pigments are typically coated with inert layers to suppress the photocatalytic activity and improve the weatherability. However, the traditional inert layers have a lower refractive index compared to TiO2, and th...TiO2 pigments are typically coated with inert layers to suppress the photocatalytic activity and improve the weatherability. However, the traditional inert layers have a lower refractive index compared to TiO2, and therefore reduce the lightening power of TiO2. In the present work, a uniform, amorphous, 2.9-nm-thick TiO2 protective layer was deposited onto the surface of anatase TiO2 pigments according to pulsed chemical vapor deposition at room temperature, with Ti Cl4 as titanium precursor. Amorphous TiO2 coating layers exhibited poor photocatalytic activity, leading to a boosted weatherability. Similarly, this coating method is also effective for TiO2 coating with amorphous SiO2 and SnO2 layers. However, the lightening power of amorphous TiO2 layer is higher than those of amorphous SiO2 and SnO2 layers. According to the measurements of photoluminescence lifetime, surface photocurrent density, charge-transfer resistance, and electron spin resonance spectroscopy, it is revealed that the amorphous layer can prevent the migration of photogenerated electrons and holes onto the surface, decreasing the densities of surface electron and hole, and thereby suppress the photocatalytic activity.展开更多
Hydroquinone(HQ)is an phenolic aromatic compound used in cosmetic medicine as skin lightening material since long time ago.Accordingly the several pathological conditions that observed,the use of HQ for this purpose w...Hydroquinone(HQ)is an phenolic aromatic compound used in cosmetic medicine as skin lightening material since long time ago.Accordingly the several pathological conditions that observed,the use of HQ for this purpose was recently contraindicated.The commonly noted health problem associated with hydroquinone use was contact dermatitis.The present study was designed and conducted to determine the HQ presence and concentrations in ten samples of skin lightening cosmetics available in the local market.GC-MS analysis was employed for detection of HQ qualitatively while HPLC analysis was used as a quantitative analysis for determination of the HQ concentrations in each sample.The results obtained indicated that the overall range of HQ levels in all respected samples ranged from 0.0039%to 0.14%.展开更多
The application of unsteady simulation to lightening urban storm waterlogged disaster involves six blocks: the main program, the database of drainage networks, the abstractions and losses block, the calculating inflow...The application of unsteady simulation to lightening urban storm waterlogged disaster involves six blocks: the main program, the database of drainage networks, the abstractions and losses block, the calculating inflow of sewer block, the drainage networks routing block and the waterlogged areas calculating block. This model can be used for simulating sewer surcharge and calculating area and water depth of waterlogged areas under storm conditions. The best design of rebuilding storm sewer system or combined sewer system can be provided by simulating existing state of built drainage pipeline. The model was used for rebuilding Shenyang drainage works last year, and the good results were obtained.展开更多
Dental caries diagnosis system has been made with a fiber lighting, camera module and band pass filter. By simply aligning a 405 nm LED (Light Emitting diode) chips directly connected polymer fibers, a compact lightin...Dental caries diagnosis system has been made with a fiber lighting, camera module and band pass filter. By simply aligning a 405 nm LED (Light Emitting diode) chips directly connected polymer fibers, a compact lighting for dental fluorescence imaging could be implemented. Special designed fiber holder with proper hole diameter was fabricated to directly connect polymer fibers with 1 mm fiber diameter and increased coupling efficiency between fibers and LEDs. Fibers connected to fiber holder were polished by polishing machine to reduce insertion loss of the fiber. Experimentally, an optical insertion loss of the fiber bundle of up to 0.8 dB was achieved. Further, LED array module was packaged with equally spaced LED chips with fiber holder on metal. Fiber lightening was fabricated with directly coupled between LED array module and fiber bundle by UV epoxy without focusing lens in order to lower the lightening temperature of intraoral camera in the human mouth. The measured temperature of fabricated fiber lightening was about 25 degree celcius. To achieve a fluorescence image and dental caries diagnosis, the proper optical filter, camera module, 405 nm fiber bundle lighting and software were investigated. The performance of the fluorescence intraoral camera with fiber lightening is confirmed by fluorescence image of human tooth.展开更多
As the core components of diesel engine,the structure and dynamic characteristics of the crankshaft has a vital role on engine performance. To Process the lightening hole with properly size in a certain location can r...As the core components of diesel engine,the structure and dynamic characteristics of the crankshaft has a vital role on engine performance. To Process the lightening hole with properly size in a certain location can reduce the weight of the crankshaft so as to,improve the dynamic characteristics and the connecting rod load of the crankshaft. Using finite element method and using three-dimensional software to model,the structural static and dynamic analysis theory to are gotten the performance and fatigue life analysis of crankshaft which have lightening hole with appropriate size. In this paper,to select the lightening hole for 25 mm size to analyze and compare the results with no hole of crankshaft analysis data can get that lightening hole can improve the crankshaft strength and the fatigue life of some location of the crankshaft.展开更多
The feasibility of a sustainable non-autoclaved cellular concrete,based on flax vegetable co-products,for the production of usable specimen in the lightweight construction field,has been investigated experimentally.Th...The feasibility of a sustainable non-autoclaved cellular concrete,based on flax vegetable co-products,for the production of usable specimen in the lightweight construction field,has been investigated experimentally.The produced specimen,containing various volume ratios of flax particles with respect to preformulatd Tradical PF70 lime binder of 0,1,and 2,were lightened by creating a porous structure in the matrix through the addition of 0.3%wt.Aluminium powder(able to react with calcium hydroxide from the binder and result in microscopic air-bubbles).Fresh and hardened specimen properties,including hydration,fresh density,porosity,hardened density,compressive and flexural strengths,toughness energy,and dry thermal conductivity at different temperatures,were assessed for varying flax-to-binder ratios.Results have shown that the addition of Aluminum powder leads to restrain the setting time delay of binder-based lime.Moreover,the hardened material displays a significant decrease in specimen density,thereby resulting in a compressive strength level compatible with that required in the cellular construction materials sector.Results also highlighted the ability of added flax to induce a change in the specimen from brittle to ductile behavior.Moreover,a high degree of thermal insulation can be achieved,which makes the cellular specimen based on flax particle suitable as insulated-bearing walls material.展开更多
Objective: To review low-voltage, high-voltage and lightening electrical burns in adults and children, identify novel areas that are not recognized and improve treatments results and outcome. Methods: An extensive lit...Objective: To review low-voltage, high-voltage and lightening electrical burns in adults and children, identify novel areas that are not recognized and improve treatments results and outcome. Methods: An extensive literature search on electrical burn injuries was performed using Ovid Medline, PubMed and Embase databases from 1976 to 2016. Studies related to electrical injury in the adult and children (< 15 years of age) population were included in our study. Fifty-one research papers and review articles were identified and included in this study. Results: Total occurrence of electrical injury among burn injuries ranged from 3.5% to 15.0%. Most of them were low voltage (73%) and one fourth were high voltage and percentage of lightening injuries were very low around 2%–4% of total cases of electrical injury. Mortality is somehow higher among high voltage electrical injuries and lightening. Most of complications of them were morbid in kidney, heart, extremities (including amputations) and nervous systems. Long-term psychological problems were reported with greater incidence rates in high-voltage injuries. Psychological and posttraumatic stress disorders were also reported. Mortality rates from electrical injuries were 2.6% in low voltage and 5.2% in high voltage. Conclusions: High-voltage injury leads to greater morbidity and mortality than low-voltage one. Lightening has mortality of about 32%, higher rates of complications and specialty long-term complications. Strict multi-specialty treatment and rehabilitations are required for proper treatment of electrical injuries.展开更多
Many countries in the world wide banned hydroquinone in cosmetics skin lightening but it is still used in most of Africa countries, including Sudan. Few studies were carried out on the side effect of hydroquinone on S...Many countries in the world wide banned hydroquinone in cosmetics skin lightening but it is still used in most of Africa countries, including Sudan. Few studies were carried out on the side effect of hydroquinone on Sudanese women. Therefore, the present study was carried out in Khartoum state in April to May/2014 to assess the awareness of Sudanese women about using hydroquinone and its probable risks. The results revealed that, highly using cosmetics containing hydroquinone by women aged between 20 - 29 years (78.3%) as well as by those classified as single (69.6%). The results also showed that the highest percentage of women was using it during evening (81.2%) and a high percentage of them was using it for skin lightening (65.2%), followed by elimination acne (20.3%) and about 10.1% for both skin lightening and elimination of acne and very little (4.3%) for freckle elimination. Moreover, the results showed a very high percentage of women (94.2%) used the chemical without being prescribed by doctors and about (85.5%) of them didn’t know its nature and risks on human health. Consequently, (50.7%) of women have had sides effects, (44.9 %) used more than one and (44.1%) used it regularly. In addition, the results revealed that a wide range of products of this chemical was available in local market with amalico (34.8%) being highly used. The study can conclude that the awareness of Sudanese women about this compound was poor and needs to be raised by health authorities.展开更多
Skin lightening and tanning are two major areas dominating the market of skincare and cosmetic products. Though the demands are originated from two different communities, the two areas share a same goal—skin colour t...Skin lightening and tanning are two major areas dominating the market of skincare and cosmetic products. Though the demands are originated from two different communities, the two areas share a same goal—skin colour tuning. The known safe compounds with skin colour tuning activities are limited. In contrary, Chinese medicinal herb provides a pool of natural bioactive compounds, which have been used in Asian countries for long time and have been tested for its toxicity. Here, we demonstrate a high throughput screening platform for potential compounds usable for skin colour tuning. From 147 natural compounds, 26 of them showed potential in skin tanning functions by using the high throughput melanogenesis platform based on the melanogenesis assay on B16 melanocytes. Five of them promoted melanogenesis by over 50%. Moreover, apart from 1, 8-dihydroxyanthraquinone, the other four compounds showed enhancement effect on tyrosinase activity. From the result, the compounds increased the Vmax of tyrosinase without changing the Km in a dose-dependent manner. Thus, there should be no irreversible structural change of the enzyme. Definitely, this report contributes to the development of personalization in skincare and cosmetic products.展开更多
Skin,as the outmost layer of human body,is frequently exposed to environmental stressors including pollutants and ultraviolet(UV),which could lead to skin disorders.Generally,skin response process to ultraviolet B(UVB...Skin,as the outmost layer of human body,is frequently exposed to environmental stressors including pollutants and ultraviolet(UV),which could lead to skin disorders.Generally,skin response process to ultraviolet B(UVB)irradiation is a nonlinear dynamic process,with unknown underlying molecular mechanism of critical transition.Here,the landscape dynamic network biomarker(lDNB)analysis of time series transcriptome data on 3D skin model was conducted to reveal the complicated process of skin response to UV irradiation at both molecular and network levels.The advanced l-DNB analysis approach showed that:(i)there was a tipping point before critical transition state during pigmentation process,validated by 3D skin model;(ii)13 core DNB genes were identified to detect the tipping point as a network biomarker,supported by computational assessment;(iii)core DNB genes such as COL7A1 and CTNNB1 can effectively predict skin lightening,validated by independent human skin data.Overall,this study provides new insights for skin response to repetitive UVB irradiation,including dynamic pathway pattern,biphasic response,and DNBs for skin lightening change,and enables us to further understand the skin resilience process after external stress.展开更多
The membrane water content of the proton exchange membrane fuel cell(PEMFC)is the most important feature required for water management of the PEMFC system.Any improper management of water in the fuel cell may lead to ...The membrane water content of the proton exchange membrane fuel cell(PEMFC)is the most important feature required for water management of the PEMFC system.Any improper management of water in the fuel cell may lead to system faults.Among various faults,flooding and drying faults are the most frequent in the PEMFC systems.This paper presents a new dynamic semi-empirical model which requires only the load current and temperature of the PEMFC system as the input while providing output voltage and membrane water content as its major outputs.Unlike other PEMFC systems,the proposed dynamic model calculates the internal partial pressure of oxygen and hydrogen rather than using special internal sensors.Moreover,the membrane water content and internal resistances of PEMFC are modelled by incorporating the load current condition and temperature of the PEMFC system.The model parameters have been extracted by using a quantum lightening search algorithm as an optimization technique,and the performance is validated with experimental data obtained from the NEXA 1.2 k W PEMFC system.To further demonstrate the capability of the model in fault detection,the variation in membrane water content has been studied via the simulation.The proposed model could be efficiently used in prognostic and diagnosis systems of PEMFC fault.展开更多
China's resolve to embrace energy-efficient lighting unleashes a powerful market potential While a lot of attention has been focused on China's energy shortage, there seemed to be little emphasis on making lig...China's resolve to embrace energy-efficient lighting unleashes a powerful market potential While a lot of attention has been focused on China's energy shortage, there seemed to be little emphasis on making lighting, which consumes as much as 12 percent of the electricity produced in the country, more energy efficient. Until fairly recently, that is. The Chinese Government and companies are promoting the use of展开更多
Nov. 26th, "the Light of Textile" 2009 China National Textile & Apparel Council Technology and Education Award ceremony held in Great Hall of the People in Beijing.
文摘Edible bird’s nest (EBN;Yan Wo), or cubilose, is originated from the salivary secretion of Aerodramus fuciphagus. In Asia, EBN is famous for its unproven skin lightening function. Here, we aim to reveal the active ingredients of EBN responsible for skin lightening function. Three major fractions were isolated from EBN water extract by chromatography using LC-MS/MS, bioactivities of these isolated fractions were analyzed by assays of tyrosinase, melanocytes and 3D human skin model, from which, N-acetylneuraminic acid (NANA), the second isolated fraction showed an inhibition effect on tyrosinase activity in a dose-dependent manner. The IC50 of tyrosinase originated from mushroom and human was 16.93 mM and 0.10 mM respectively. Furthermore, only EBN with higher content of NANA (e.g. White and Red EBN), but not EBN with less NANA (e.g. Grass EBN), showed promising skin lightening function. This is the first report to reveal NANA being an active ingredient of EBN on skin lightening function.
基金Supported by the National Key R&D Program of China(2018YFB0605700).
文摘TiO2 pigments are typically coated with inert layers to suppress the photocatalytic activity and improve the weatherability. However, the traditional inert layers have a lower refractive index compared to TiO2, and therefore reduce the lightening power of TiO2. In the present work, a uniform, amorphous, 2.9-nm-thick TiO2 protective layer was deposited onto the surface of anatase TiO2 pigments according to pulsed chemical vapor deposition at room temperature, with Ti Cl4 as titanium precursor. Amorphous TiO2 coating layers exhibited poor photocatalytic activity, leading to a boosted weatherability. Similarly, this coating method is also effective for TiO2 coating with amorphous SiO2 and SnO2 layers. However, the lightening power of amorphous TiO2 layer is higher than those of amorphous SiO2 and SnO2 layers. According to the measurements of photoluminescence lifetime, surface photocurrent density, charge-transfer resistance, and electron spin resonance spectroscopy, it is revealed that the amorphous layer can prevent the migration of photogenerated electrons and holes onto the surface, decreasing the densities of surface electron and hole, and thereby suppress the photocatalytic activity.
文摘Hydroquinone(HQ)is an phenolic aromatic compound used in cosmetic medicine as skin lightening material since long time ago.Accordingly the several pathological conditions that observed,the use of HQ for this purpose was recently contraindicated.The commonly noted health problem associated with hydroquinone use was contact dermatitis.The present study was designed and conducted to determine the HQ presence and concentrations in ten samples of skin lightening cosmetics available in the local market.GC-MS analysis was employed for detection of HQ qualitatively while HPLC analysis was used as a quantitative analysis for determination of the HQ concentrations in each sample.The results obtained indicated that the overall range of HQ levels in all respected samples ranged from 0.0039%to 0.14%.
文摘The application of unsteady simulation to lightening urban storm waterlogged disaster involves six blocks: the main program, the database of drainage networks, the abstractions and losses block, the calculating inflow of sewer block, the drainage networks routing block and the waterlogged areas calculating block. This model can be used for simulating sewer surcharge and calculating area and water depth of waterlogged areas under storm conditions. The best design of rebuilding storm sewer system or combined sewer system can be provided by simulating existing state of built drainage pipeline. The model was used for rebuilding Shenyang drainage works last year, and the good results were obtained.
文摘Dental caries diagnosis system has been made with a fiber lighting, camera module and band pass filter. By simply aligning a 405 nm LED (Light Emitting diode) chips directly connected polymer fibers, a compact lighting for dental fluorescence imaging could be implemented. Special designed fiber holder with proper hole diameter was fabricated to directly connect polymer fibers with 1 mm fiber diameter and increased coupling efficiency between fibers and LEDs. Fibers connected to fiber holder were polished by polishing machine to reduce insertion loss of the fiber. Experimentally, an optical insertion loss of the fiber bundle of up to 0.8 dB was achieved. Further, LED array module was packaged with equally spaced LED chips with fiber holder on metal. Fiber lightening was fabricated with directly coupled between LED array module and fiber bundle by UV epoxy without focusing lens in order to lower the lightening temperature of intraoral camera in the human mouth. The measured temperature of fabricated fiber lightening was about 25 degree celcius. To achieve a fluorescence image and dental caries diagnosis, the proper optical filter, camera module, 405 nm fiber bundle lighting and software were investigated. The performance of the fluorescence intraoral camera with fiber lightening is confirmed by fluorescence image of human tooth.
文摘As the core components of diesel engine,the structure and dynamic characteristics of the crankshaft has a vital role on engine performance. To Process the lightening hole with properly size in a certain location can reduce the weight of the crankshaft so as to,improve the dynamic characteristics and the connecting rod load of the crankshaft. Using finite element method and using three-dimensional software to model,the structural static and dynamic analysis theory to are gotten the performance and fatigue life analysis of crankshaft which have lightening hole with appropriate size. In this paper,to select the lightening hole for 25 mm size to analyze and compare the results with no hole of crankshaft analysis data can get that lightening hole can improve the crankshaft strength and the fatigue life of some location of the crankshaft.
文摘The feasibility of a sustainable non-autoclaved cellular concrete,based on flax vegetable co-products,for the production of usable specimen in the lightweight construction field,has been investigated experimentally.The produced specimen,containing various volume ratios of flax particles with respect to preformulatd Tradical PF70 lime binder of 0,1,and 2,were lightened by creating a porous structure in the matrix through the addition of 0.3%wt.Aluminium powder(able to react with calcium hydroxide from the binder and result in microscopic air-bubbles).Fresh and hardened specimen properties,including hydration,fresh density,porosity,hardened density,compressive and flexural strengths,toughness energy,and dry thermal conductivity at different temperatures,were assessed for varying flax-to-binder ratios.Results have shown that the addition of Aluminum powder leads to restrain the setting time delay of binder-based lime.Moreover,the hardened material displays a significant decrease in specimen density,thereby resulting in a compressive strength level compatible with that required in the cellular construction materials sector.Results also highlighted the ability of added flax to induce a change in the specimen from brittle to ductile behavior.Moreover,a high degree of thermal insulation can be achieved,which makes the cellular specimen based on flax particle suitable as insulated-bearing walls material.
文摘Objective: To review low-voltage, high-voltage and lightening electrical burns in adults and children, identify novel areas that are not recognized and improve treatments results and outcome. Methods: An extensive literature search on electrical burn injuries was performed using Ovid Medline, PubMed and Embase databases from 1976 to 2016. Studies related to electrical injury in the adult and children (< 15 years of age) population were included in our study. Fifty-one research papers and review articles were identified and included in this study. Results: Total occurrence of electrical injury among burn injuries ranged from 3.5% to 15.0%. Most of them were low voltage (73%) and one fourth were high voltage and percentage of lightening injuries were very low around 2%–4% of total cases of electrical injury. Mortality is somehow higher among high voltage electrical injuries and lightening. Most of complications of them were morbid in kidney, heart, extremities (including amputations) and nervous systems. Long-term psychological problems were reported with greater incidence rates in high-voltage injuries. Psychological and posttraumatic stress disorders were also reported. Mortality rates from electrical injuries were 2.6% in low voltage and 5.2% in high voltage. Conclusions: High-voltage injury leads to greater morbidity and mortality than low-voltage one. Lightening has mortality of about 32%, higher rates of complications and specialty long-term complications. Strict multi-specialty treatment and rehabilitations are required for proper treatment of electrical injuries.
文摘Many countries in the world wide banned hydroquinone in cosmetics skin lightening but it is still used in most of Africa countries, including Sudan. Few studies were carried out on the side effect of hydroquinone on Sudanese women. Therefore, the present study was carried out in Khartoum state in April to May/2014 to assess the awareness of Sudanese women about using hydroquinone and its probable risks. The results revealed that, highly using cosmetics containing hydroquinone by women aged between 20 - 29 years (78.3%) as well as by those classified as single (69.6%). The results also showed that the highest percentage of women was using it during evening (81.2%) and a high percentage of them was using it for skin lightening (65.2%), followed by elimination acne (20.3%) and about 10.1% for both skin lightening and elimination of acne and very little (4.3%) for freckle elimination. Moreover, the results showed a very high percentage of women (94.2%) used the chemical without being prescribed by doctors and about (85.5%) of them didn’t know its nature and risks on human health. Consequently, (50.7%) of women have had sides effects, (44.9 %) used more than one and (44.1%) used it regularly. In addition, the results revealed that a wide range of products of this chemical was available in local market with amalico (34.8%) being highly used. The study can conclude that the awareness of Sudanese women about this compound was poor and needs to be raised by health authorities.
文摘Skin lightening and tanning are two major areas dominating the market of skincare and cosmetic products. Though the demands are originated from two different communities, the two areas share a same goal—skin colour tuning. The known safe compounds with skin colour tuning activities are limited. In contrary, Chinese medicinal herb provides a pool of natural bioactive compounds, which have been used in Asian countries for long time and have been tested for its toxicity. Here, we demonstrate a high throughput screening platform for potential compounds usable for skin colour tuning. From 147 natural compounds, 26 of them showed potential in skin tanning functions by using the high throughput melanogenesis platform based on the melanogenesis assay on B16 melanocytes. Five of them promoted melanogenesis by over 50%. Moreover, apart from 1, 8-dihydroxyanthraquinone, the other four compounds showed enhancement effect on tyrosinase activity. From the result, the compounds increased the Vmax of tyrosinase without changing the Km in a dose-dependent manner. Thus, there should be no irreversible structural change of the enzyme. Definitely, this report contributes to the development of personalization in skincare and cosmetic products.
基金partially supported by the National Natural Science Foundation of China(31930022,31771476,12026608,12042104,and 11871456)the Strategic Priority Project of CAS(XDB38040400)+1 种基金the National Key R&D Program of China(2017YFA0505500)JST Moonshot R&D program(JP MJMS2021 to L.C.).
文摘Skin,as the outmost layer of human body,is frequently exposed to environmental stressors including pollutants and ultraviolet(UV),which could lead to skin disorders.Generally,skin response process to ultraviolet B(UVB)irradiation is a nonlinear dynamic process,with unknown underlying molecular mechanism of critical transition.Here,the landscape dynamic network biomarker(lDNB)analysis of time series transcriptome data on 3D skin model was conducted to reveal the complicated process of skin response to UV irradiation at both molecular and network levels.The advanced l-DNB analysis approach showed that:(i)there was a tipping point before critical transition state during pigmentation process,validated by 3D skin model;(ii)13 core DNB genes were identified to detect the tipping point as a network biomarker,supported by computational assessment;(iii)core DNB genes such as COL7A1 and CTNNB1 can effectively predict skin lightening,validated by independent human skin data.Overall,this study provides new insights for skin response to repetitive UVB irradiation,including dynamic pathway pattern,biphasic response,and DNBs for skin lightening change,and enables us to further understand the skin resilience process after external stress.
基金supported by United Arab Emirates University(Emirates Centre for Energy and Environment Research)(No.31R067)。
文摘The membrane water content of the proton exchange membrane fuel cell(PEMFC)is the most important feature required for water management of the PEMFC system.Any improper management of water in the fuel cell may lead to system faults.Among various faults,flooding and drying faults are the most frequent in the PEMFC systems.This paper presents a new dynamic semi-empirical model which requires only the load current and temperature of the PEMFC system as the input while providing output voltage and membrane water content as its major outputs.Unlike other PEMFC systems,the proposed dynamic model calculates the internal partial pressure of oxygen and hydrogen rather than using special internal sensors.Moreover,the membrane water content and internal resistances of PEMFC are modelled by incorporating the load current condition and temperature of the PEMFC system.The model parameters have been extracted by using a quantum lightening search algorithm as an optimization technique,and the performance is validated with experimental data obtained from the NEXA 1.2 k W PEMFC system.To further demonstrate the capability of the model in fault detection,the variation in membrane water content has been studied via the simulation.The proposed model could be efficiently used in prognostic and diagnosis systems of PEMFC fault.
文摘China's resolve to embrace energy-efficient lighting unleashes a powerful market potential While a lot of attention has been focused on China's energy shortage, there seemed to be little emphasis on making lighting, which consumes as much as 12 percent of the electricity produced in the country, more energy efficient. Until fairly recently, that is. The Chinese Government and companies are promoting the use of
文摘Nov. 26th, "the Light of Textile" 2009 China National Textile & Apparel Council Technology and Education Award ceremony held in Great Hall of the People in Beijing.
