The automatic detection and analysis of sunspots play a crucial role in understanding solar dynamics and predicting space weather events.This paper proposes a novel method for sunspot group detection and classificatio...The automatic detection and analysis of sunspots play a crucial role in understanding solar dynamics and predicting space weather events.This paper proposes a novel method for sunspot group detection and classification called the dual stream Convolutional Neural Network with Attention Mechanism(DSCNN-AM).The network consists of two parallel streams each processing different input data allowing for joint processing of spatial and temporal information while classifying sunspots.It takes in the white light images as well as the corresponding magnetic images that reveal both the optical and magnetic features of sunspots.The extracted features are then fused and processed by fully connected layers to perform detection and classification.The attention mechanism is further integrated to address the“edge dimming”problem which improves the model’s ability to handle sunspots near the edge of the solar disk.The network is trained and tested on the SOLAR-STORM1 data set.The results demonstrate that the DSCNN-AM achieves superior performance compared to existing methods,with a total accuracy exceeding 90%.展开更多
With great advance of ground-based extensive air shower arrays,such as LHAASO and HAWC,many very high energy(VHE)gamma-ray sources have been discovered and are being monitored regardless of the day and the night.Hence...With great advance of ground-based extensive air shower arrays,such as LHAASO and HAWC,many very high energy(VHE)gamma-ray sources have been discovered and are being monitored regardless of the day and the night.Hence,the Sun and Moon would have some impacts on the observation of gamma-ray sources,which have not been taken into account in previous analysis.In this paper,the influence of the Sun and Moon on the observation of very high energy gamma-ray sources when they are near the line of sight of the Sun or Moon is estimated.The tracks of all the known VHE sources are scanned and several VHE sources are found to be very close to the line of sight of the Sun or Moon during some period.The absorption of very high energy gamma rays by sunlight is estimated with detailed method and some useful conclusions are achieved.The main influence is the block of the Sun and Moon on gamma rays and the shadow on the cosmic ray background.The influence is investigated considering the detector angular resolution and some strategies on data analysis are proposed to avoid the underestimation of the gamma-ray emission.展开更多
A new non-linear bending-torsional coupled model for double-row planetary gear set was proposed, and planet's eccentricity error, static transmission error, and time-varying meshing stiffness were taken into consi...A new non-linear bending-torsional coupled model for double-row planetary gear set was proposed, and planet's eccentricity error, static transmission error, and time-varying meshing stiffness were taken into consideration. The solution of differential governing equation of motion is determined by applying the Fourier series method. The behaviors of dynamic load sharing characteristics affected by the system parameters including gear eccentricities error, ring gear's supporting stiffness, planet's bearing stiffness, torsional stiffness of first stage carrier and input rotation rate were investigated qualitatively and systematically, and sun gear radial orbits at first and second stage were explored as well. Some theoretical results are summarized as guidelines for further research and design of double-row planetary gear train at last.展开更多
We present properties of intensity oscillations of a sunspot in the photo- sphere and chromosphere using G band and Ca u H filtergrams from Hinode. Intensity power maps as function of magnetic field strength and frequ...We present properties of intensity oscillations of a sunspot in the photo- sphere and chromosphere using G band and Ca u H filtergrams from Hinode. Intensity power maps as function of magnetic field strength and frequency reveal reduction of power in the G band with an increase in photospheric magnetic field strength at all frequencies. In Ca II H, however, stronger fields exhibit more power at high frequen- cies, particularly in the 4.5-8.0 mHz band. Power distributions in different locations of the active region show that the oscillations in Ca II H exhibit more power compared to that of the G band. We also relate the power in intensity oscillations with differ- ent components of the photospheric vector magnetic field using near simultaneous spectro-polarimetric observations of the sunspot from the Hinode spectropolarime- ter. The photospheric umbral power is strongly anti-correlated with the magnetic field strength and its line-of-sight component but there is a good correlation with the trans- verse component. A reversal of this trend is observed in the chromosphere except at low frequencies (V≤ 1.5 mHz). The power in sunspot penumbrae is anti-correlated with the magnetic field parameters at all frequencies (1.0 ≤ v ≤ 8.0 mHz) in both the photosphere and chromosphere, except that the chromospheric power shows a strong correlation in the frequency range 3-3.5 mHz.展开更多
We propose that grand minima in solar activity are caused by simultane- ous fluctuations in the meridional circulation and the Babcock-Leighton mechanism for the poloidal field generation in the flux transport dynamo ...We propose that grand minima in solar activity are caused by simultane- ous fluctuations in the meridional circulation and the Babcock-Leighton mechanism for the poloidal field generation in the flux transport dynamo model. We present the following results: (a) fluctuations in the meridional circulation are more effective in producing grand minima; (b) both sudden and gradual initiations of grand minima are possible; (c) distributions of durations and waiting times between grand minima seem to be exponential; (d) the coherence time of the meridional circulation has an effect on the number and the average duration of grand minima, with a coherence time of about 30 yr being consistent with observational data. We also study the occurrence of grand maxima and find that the distributions of durations and waiting times between grand maxima are also exponential, like the grand minima. Finally we address the question of whether the Babcock-Leighton mechanism can be operative during grand minima when there are no sunspots. We show that an a-effect restricted to the upper portions of the convection zone can pull the dynamo out of the grand minima and can match various observational requirements if the amplitude of this a-effect is suitably fine-tuned.展开更多
As typical visual culture symbol of China, the visual image of Sun Wukong firstly appeared on the mural of Yulin Caves of Dunhuang in Western Xia regime and the story of Monk Tang and his prentices on the mural in Yua...As typical visual culture symbol of China, the visual image of Sun Wukong firstly appeared on the mural of Yulin Caves of Dunhuang in Western Xia regime and the story of Monk Tang and his prentices on the mural in Yuan Dynasty. Up to Yuan Dynasty, it became very popular. Since the novel Pilgrimage to the West was published, the visual image of Sun Wukong has appeared in the visual carriers of wood block, colored drawing, paper-cut, traditional Chinese opera, film, television, ad, cartoon and so on. European countries, America, Japan and South Korea use advanced film and TV technology and digital technology to deduce, model, adapt and simulate the visual image of Sun Wukong. This paper investigates the construction of the visual image of Sun Wukong in China and extraterritorial countries and regions, tries to explore Chinese "visual" experience in mediaeval times and especially modern times and seeks a clue for understanding Chinese problem of visual expression.展开更多
A vast number of physical processes involving oscillations of a bounded viscous fluid are relevantly influenced by acoustic streaming. When this happens a steady circulation of fluid develops in a thin boundary adjace...A vast number of physical processes involving oscillations of a bounded viscous fluid are relevantly influenced by acoustic streaming. When this happens a steady circulation of fluid develops in a thin boundary adjacent to the interface. Some examples are refracted sound waves, a fluid inside a spherical cavity undergoing torsional oscillations or a pulsating liquid droplet. Steady streaming around circular interfaces consists of a hemispherically symmetric recirculation of fluid from the equatorial plane to the polar axes closely resembling the meridional circulation pattern observed in the Sun's convection zone that determines the solar cycle. In this paper, it is argued that the acoustic pulsations exhibited by the Sun would lead to acoustic streaming in the boundary of the convection zone. A simple estimation using a typical dominant frequency of 3 mHz and the observed surface oscillation amplitude yields a steady streaming velocity Us - 10 m s^-1, which is on the order of the meridional circulation velocity observed in the Sun's convection zone.展开更多
Taking the advantage of sun glitter(SG)observed from high-resolution satellites Gaofen-1(GF-1)and Gaofen-6(GF-6),a new method named Shield and Vortex 1-2(SAV1-2)for extracting spatial texture information from sun glit...Taking the advantage of sun glitter(SG)observed from high-resolution satellites Gaofen-1(GF-1)and Gaofen-6(GF-6),a new method named Shield and Vortex 1-2(SAV1-2)for extracting spatial texture information from sun glitter was established.Sea surface texture detail information around Diaoyu Dao and its affiliated islands was extracted using SAV1-2.Meanwhile,the dynamic characteristics of the water environment were analyzed by combining the water color,temperature and dynamic data.The results show the following information.(1)Stable westward shield effect and eastward Karman vortex streets,extracted from SG,appear upstream(westward)and downstream(eastward)of the Diaoyu Dao and its affiliated islands respectively.(2)The dominant direction of the Kuroshio Current in the Diaoyu Dao and its affiliated islands area is east,the Diaoyu Dao and its affiliated islands interacting with Kuroshio,inducing western shield and eastern shelter and wake.Furthermore,wave intervals of the shield in front of the island range from hundreds to thousands of metres,and extend wider than the island itself.(3)Combining with high-resolution sea surface temperature(SST)and chlorophyll a(Chl a)concentration,the directional changes of water color elements are mutually supported and proved with the stable shield(wave packet)effect in the west and vortex street effect in the east.The change of SST upstream of the island(western shield area)is not significant,the temperature in the downstream shelter area decreases slightly,and the SST in the downstream wake area shows a general trend of obvious decrease.The wake area is dominated by Karman vortex streets in shape,supplementing by vortices.The concentration of Chl a in the west shield of island is as low as that in downstream shelter area,while it increases significantly in the downstream wake area with shape in eddy or ribbon.(4)The SAV methods of extracting sea surface texture detail using SG can be widely used in different sea areas and water quality.This paper can provide reference for the protection and development of Diaoyu Dao and its affiliated islands and its surrounding waters.It is suggested that some kind of current buffer,such as marine wind farm,should be established in the western waters of Diaoyu Dao and its affiliated islands to protect the islands,and marine pasture should be developed in the downstream of eastern waters of Diaoyu Dao and its affiliated islands.展开更多
China is the largest solar water heater producer and market in the world.Despite the fast growth and an installed capacity that accounts for the majority of the global gross,China's per capita solar hot water capa...China is the largest solar water heater producer and market in the world.Despite the fast growth and an installed capacity that accounts for the majority of the global gross,China's per capita solar hot water capacity is still very low,implying a huge margin of market potential;and the recognition of the industry in the global market is handicapped by the scattered scale of production and inconsistent product quality.To ensure continued growth of China's solar water heating(SWH) industry,Chinese Government has established a series of national SWH standards,three national testing centers,and a certification program to lay the foundation for the development of the Golden Sun product labeling system.China General Certification Center(CGC) developed the Golden Sun product certification and labeling system on a pass/fail basis evaluating with established criteria.The system was designed to help manufacturers acclimate to explicit consistent requirements and to identify and fix the deficiencies in the design and execution of the program itself.Timely revision and integration of the national standards are recommended to accommodate the test procedures and requirements to new technologies and the evolving SWH market.Strict implementation of the Golden Sun certification and labeling system are suggested to avail improving the quality control and forging internationally reputable brands of Chinese solar water heating products.展开更多
Fishes are suitable for sun drying and smoking. But their high contains of unsaturated fatty acids mak</span><span style="font-family:Verdana;">e</span><span style="font-family:Verd...Fishes are suitable for sun drying and smoking. But their high contains of unsaturated fatty acids mak</span><span style="font-family:Verdana;">e</span><span style="font-family:Verdana;"> them very prone to lipid oxidation. However, some plants are rich in natural antioxidants and have been shown to be potent inhibitors of lipid oxidation during processing of meat. The effect of three aqueous plants extracts on lipid stability of </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Oreochromis niloticus</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;"> collected in Far-North Cameroon during processing was evaluated. Results show the high nutritious of these fish with high levels of proteins, lipid and ash (71.02</span><span style="font-family:Verdana;">%</span><span style="font-family:Verdana;">, 13.71</span><span style="font-family:Verdana;">%</span><span style="font-family:Verdana;"> and 10.65%, respectively). It has been observed that oleic acid (C18:1), followed by palmitic acid (C16:0) and linoleic acid (C18:2) are the most dominant fatty acids present in </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Oreochromis niloticus</span></i><i><span style="font-family:Verdana;"></i></span></i><i><span style="font-family:""> </span></i><span style="font-family:Verdana;">lipids. Their lipid also showed a much higher content of omega-3 polyunsaturated fatty acids (PUFA) compared to omega 6 PUFA. The total phenolic contents (TPC) of the three plants ranged from 12</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">150 to 16</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">050 mg/100</span><span style="font-family:""> </span><span style="font-family:Verdana;">g. The leaves of </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Moringa oleifera</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;"> exhibited </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">higher content of TPC. The results of iodine, peroxide value and thiobarbituric acids test were revealed that the aqueous extracts of the tree plants had antioxidant properties. These plants extracts inhibit lipid oxidation of </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Oreochromis niloticus</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;"> during processing. Increasing of the concentration of plant extracts enhanced their antioxidant activities and the highest oxidation inhibitor was obtained at 30</span><span style="font-family:""> </span><span style="font-family:Verdana;">g/l. </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Moringa oleifera</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;"> leaves inhibit highly the lipid oxidation of </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Oreochromis niloticus</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;">.展开更多
It is universally known that the preparation of high quality graphene on a large scale and in a cost-effective manner is essential for many technological applications. Graphene oxide (GO) has emerged as the precursor ...It is universally known that the preparation of high quality graphene on a large scale and in a cost-effective manner is essential for many technological applications. Graphene oxide (GO) has emerged as the precursor of choice for bulk production of graphene-based materials, as it can be synthesized from inexpensive graphite powders. In this paper, a simple method is described for reduction of GO solution by a free and green irradiation based technique. The majority of oxygen-containing functional groups of GO are removed by sun light. This methodology provides an effective way to quantitatively produce high quality graphene sheets. This paper presents irradiation by sun light of synthesized graphene oxide nano-flakes prepared by Hummer’s method. These nano-flakes have been successfully reduced while the dynamic of this irradiation process is discussed. The irradiated nano-flakes of graphene oxide have been investigated using X-Ray diffraction, ATR-FTIR and UV-Vis-NIR.展开更多
文摘The automatic detection and analysis of sunspots play a crucial role in understanding solar dynamics and predicting space weather events.This paper proposes a novel method for sunspot group detection and classification called the dual stream Convolutional Neural Network with Attention Mechanism(DSCNN-AM).The network consists of two parallel streams each processing different input data allowing for joint processing of spatial and temporal information while classifying sunspots.It takes in the white light images as well as the corresponding magnetic images that reveal both the optical and magnetic features of sunspots.The extracted features are then fused and processed by fully connected layers to perform detection and classification.The attention mechanism is further integrated to address the“edge dimming”problem which improves the model’s ability to handle sunspots near the edge of the solar disk.The network is trained and tested on the SOLAR-STORM1 data set.The results demonstrate that the DSCNN-AM achieves superior performance compared to existing methods,with a total accuracy exceeding 90%.
基金supported by the National Natural Science Foundation of China under grant Nos.12393854,12022502 and 12263007by the High-level Talent Support program of Yunnan Province。
文摘With great advance of ground-based extensive air shower arrays,such as LHAASO and HAWC,many very high energy(VHE)gamma-ray sources have been discovered and are being monitored regardless of the day and the night.Hence,the Sun and Moon would have some impacts on the observation of gamma-ray sources,which have not been taken into account in previous analysis.In this paper,the influence of the Sun and Moon on the observation of very high energy gamma-ray sources when they are near the line of sight of the Sun or Moon is estimated.The tracks of all the known VHE sources are scanned and several VHE sources are found to be very close to the line of sight of the Sun or Moon during some period.The absorption of very high energy gamma rays by sunlight is estimated with detailed method and some useful conclusions are achieved.The main influence is the block of the Sun and Moon on gamma rays and the shadow on the cosmic ray background.The influence is investigated considering the detector angular resolution and some strategies on data analysis are proposed to avoid the underestimation of the gamma-ray emission.
基金Projects(NZ2013303,NZ2014201)supported by the National Natural Science Foundation of ChinaProjects(51375226,51305196,51475226)supported by the Fundamental Research Funds for the Central Universities,China
文摘A new non-linear bending-torsional coupled model for double-row planetary gear set was proposed, and planet's eccentricity error, static transmission error, and time-varying meshing stiffness were taken into consideration. The solution of differential governing equation of motion is determined by applying the Fourier series method. The behaviors of dynamic load sharing characteristics affected by the system parameters including gear eccentricities error, ring gear's supporting stiffness, planet's bearing stiffness, torsional stiffness of first stage carrier and input rotation rate were investigated qualitatively and systematically, and sun gear radial orbits at first and second stage were explored as well. Some theoretical results are summarized as guidelines for further research and design of double-row planetary gear train at last.
基金Support for the post-launch operation is provided by JAXA and NAOJ (Japan), STFC (UK), NASA (USA), ESA and NSC (Norway)financial the German Science Foundation (DFG) under grant DE 787/3-1
文摘We present properties of intensity oscillations of a sunspot in the photo- sphere and chromosphere using G band and Ca u H filtergrams from Hinode. Intensity power maps as function of magnetic field strength and frequency reveal reduction of power in the G band with an increase in photospheric magnetic field strength at all frequencies. In Ca II H, however, stronger fields exhibit more power at high frequen- cies, particularly in the 4.5-8.0 mHz band. Power distributions in different locations of the active region show that the oscillations in Ca II H exhibit more power compared to that of the G band. We also relate the power in intensity oscillations with differ- ent components of the photospheric vector magnetic field using near simultaneous spectro-polarimetric observations of the sunspot from the Hinode spectropolarime- ter. The photospheric umbral power is strongly anti-correlated with the magnetic field strength and its line-of-sight component but there is a good correlation with the trans- verse component. A reversal of this trend is observed in the chromosphere except at low frequencies (V≤ 1.5 mHz). The power in sunspot penumbrae is anti-correlated with the magnetic field parameters at all frequencies (1.0 ≤ v ≤ 8.0 mHz) in both the photosphere and chromosphere, except that the chromospheric power shows a strong correlation in the frequency range 3-3.5 mHz.
基金support through the JC Bose Fellowship(project No.SR/S2/JCB-61/2009)
文摘We propose that grand minima in solar activity are caused by simultane- ous fluctuations in the meridional circulation and the Babcock-Leighton mechanism for the poloidal field generation in the flux transport dynamo model. We present the following results: (a) fluctuations in the meridional circulation are more effective in producing grand minima; (b) both sudden and gradual initiations of grand minima are possible; (c) distributions of durations and waiting times between grand minima seem to be exponential; (d) the coherence time of the meridional circulation has an effect on the number and the average duration of grand minima, with a coherence time of about 30 yr being consistent with observational data. We also study the occurrence of grand maxima and find that the distributions of durations and waiting times between grand maxima are also exponential, like the grand minima. Finally we address the question of whether the Babcock-Leighton mechanism can be operative during grand minima when there are no sunspots. We show that an a-effect restricted to the upper portions of the convection zone can pull the dynamo out of the grand minima and can match various observational requirements if the amplitude of this a-effect is suitably fine-tuned.
基金Acknowledgements: This paper was sponsored by China National Social Science Foundation "Research on the Fundamental Problems of the Contemporary Aesthetics and Criticism Patterns" (15ZDB023).
文摘As typical visual culture symbol of China, the visual image of Sun Wukong firstly appeared on the mural of Yulin Caves of Dunhuang in Western Xia regime and the story of Monk Tang and his prentices on the mural in Yuan Dynasty. Up to Yuan Dynasty, it became very popular. Since the novel Pilgrimage to the West was published, the visual image of Sun Wukong has appeared in the visual carriers of wood block, colored drawing, paper-cut, traditional Chinese opera, film, television, ad, cartoon and so on. European countries, America, Japan and South Korea use advanced film and TV technology and digital technology to deduce, model, adapt and simulate the visual image of Sun Wukong. This paper investigates the construction of the visual image of Sun Wukong in China and extraterritorial countries and regions, tries to explore Chinese "visual" experience in mediaeval times and especially modern times and seeks a clue for understanding Chinese problem of visual expression.
基金supports by the Andalusian Regional Government (Junta de Andalucia, contract FQM-5735)Spanish Government Agency Ministerio de Ciencia e Innovacion (contract CTQ201452763-C2-2-R)
文摘A vast number of physical processes involving oscillations of a bounded viscous fluid are relevantly influenced by acoustic streaming. When this happens a steady circulation of fluid develops in a thin boundary adjacent to the interface. Some examples are refracted sound waves, a fluid inside a spherical cavity undergoing torsional oscillations or a pulsating liquid droplet. Steady streaming around circular interfaces consists of a hemispherically symmetric recirculation of fluid from the equatorial plane to the polar axes closely resembling the meridional circulation pattern observed in the Sun's convection zone that determines the solar cycle. In this paper, it is argued that the acoustic pulsations exhibited by the Sun would lead to acoustic streaming in the boundary of the convection zone. A simple estimation using a typical dominant frequency of 3 mHz and the observed surface oscillation amplitude yields a steady streaming velocity Us - 10 m s^-1, which is on the order of the meridional circulation velocity observed in the Sun's convection zone.
基金The Science Foundation of Donghai Laboratory under contract No.DH-2022KF01010the Zhejiang Key Science and Technology Project under contract No.2020C02004+1 种基金the Basic Public Welfare Research Program of Zhejiang Province under contract No.LGF21D010004the Research on Group Ideological and Political Subject Teaching Model of Ocean Remote Sensing under contract No.132.
文摘Taking the advantage of sun glitter(SG)observed from high-resolution satellites Gaofen-1(GF-1)and Gaofen-6(GF-6),a new method named Shield and Vortex 1-2(SAV1-2)for extracting spatial texture information from sun glitter was established.Sea surface texture detail information around Diaoyu Dao and its affiliated islands was extracted using SAV1-2.Meanwhile,the dynamic characteristics of the water environment were analyzed by combining the water color,temperature and dynamic data.The results show the following information.(1)Stable westward shield effect and eastward Karman vortex streets,extracted from SG,appear upstream(westward)and downstream(eastward)of the Diaoyu Dao and its affiliated islands respectively.(2)The dominant direction of the Kuroshio Current in the Diaoyu Dao and its affiliated islands area is east,the Diaoyu Dao and its affiliated islands interacting with Kuroshio,inducing western shield and eastern shelter and wake.Furthermore,wave intervals of the shield in front of the island range from hundreds to thousands of metres,and extend wider than the island itself.(3)Combining with high-resolution sea surface temperature(SST)and chlorophyll a(Chl a)concentration,the directional changes of water color elements are mutually supported and proved with the stable shield(wave packet)effect in the west and vortex street effect in the east.The change of SST upstream of the island(western shield area)is not significant,the temperature in the downstream shelter area decreases slightly,and the SST in the downstream wake area shows a general trend of obvious decrease.The wake area is dominated by Karman vortex streets in shape,supplementing by vortices.The concentration of Chl a in the west shield of island is as low as that in downstream shelter area,while it increases significantly in the downstream wake area with shape in eddy or ribbon.(4)The SAV methods of extracting sea surface texture detail using SG can be widely used in different sea areas and water quality.This paper can provide reference for the protection and development of Diaoyu Dao and its affiliated islands and its surrounding waters.It is suggested that some kind of current buffer,such as marine wind farm,should be established in the western waters of Diaoyu Dao and its affiliated islands to protect the islands,and marine pasture should be developed in the downstream of eastern waters of Diaoyu Dao and its affiliated islands.
文摘China is the largest solar water heater producer and market in the world.Despite the fast growth and an installed capacity that accounts for the majority of the global gross,China's per capita solar hot water capacity is still very low,implying a huge margin of market potential;and the recognition of the industry in the global market is handicapped by the scattered scale of production and inconsistent product quality.To ensure continued growth of China's solar water heating(SWH) industry,Chinese Government has established a series of national SWH standards,three national testing centers,and a certification program to lay the foundation for the development of the Golden Sun product labeling system.China General Certification Center(CGC) developed the Golden Sun product certification and labeling system on a pass/fail basis evaluating with established criteria.The system was designed to help manufacturers acclimate to explicit consistent requirements and to identify and fix the deficiencies in the design and execution of the program itself.Timely revision and integration of the national standards are recommended to accommodate the test procedures and requirements to new technologies and the evolving SWH market.Strict implementation of the Golden Sun certification and labeling system are suggested to avail improving the quality control and forging internationally reputable brands of Chinese solar water heating products.
文摘Fishes are suitable for sun drying and smoking. But their high contains of unsaturated fatty acids mak</span><span style="font-family:Verdana;">e</span><span style="font-family:Verdana;"> them very prone to lipid oxidation. However, some plants are rich in natural antioxidants and have been shown to be potent inhibitors of lipid oxidation during processing of meat. The effect of three aqueous plants extracts on lipid stability of </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Oreochromis niloticus</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;"> collected in Far-North Cameroon during processing was evaluated. Results show the high nutritious of these fish with high levels of proteins, lipid and ash (71.02</span><span style="font-family:Verdana;">%</span><span style="font-family:Verdana;">, 13.71</span><span style="font-family:Verdana;">%</span><span style="font-family:Verdana;"> and 10.65%, respectively). It has been observed that oleic acid (C18:1), followed by palmitic acid (C16:0) and linoleic acid (C18:2) are the most dominant fatty acids present in </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Oreochromis niloticus</span></i><i><span style="font-family:Verdana;"></i></span></i><i><span style="font-family:""> </span></i><span style="font-family:Verdana;">lipids. Their lipid also showed a much higher content of omega-3 polyunsaturated fatty acids (PUFA) compared to omega 6 PUFA. The total phenolic contents (TPC) of the three plants ranged from 12</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">150 to 16</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;">050 mg/100</span><span style="font-family:""> </span><span style="font-family:Verdana;">g. The leaves of </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Moringa oleifera</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;"> exhibited </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">higher content of TPC. The results of iodine, peroxide value and thiobarbituric acids test were revealed that the aqueous extracts of the tree plants had antioxidant properties. These plants extracts inhibit lipid oxidation of </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Oreochromis niloticus</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;"> during processing. Increasing of the concentration of plant extracts enhanced their antioxidant activities and the highest oxidation inhibitor was obtained at 30</span><span style="font-family:""> </span><span style="font-family:Verdana;">g/l. </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Moringa oleifera</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;"> leaves inhibit highly the lipid oxidation of </span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">Oreochromis niloticus</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:Verdana;">.
文摘It is universally known that the preparation of high quality graphene on a large scale and in a cost-effective manner is essential for many technological applications. Graphene oxide (GO) has emerged as the precursor of choice for bulk production of graphene-based materials, as it can be synthesized from inexpensive graphite powders. In this paper, a simple method is described for reduction of GO solution by a free and green irradiation based technique. The majority of oxygen-containing functional groups of GO are removed by sun light. This methodology provides an effective way to quantitatively produce high quality graphene sheets. This paper presents irradiation by sun light of synthesized graphene oxide nano-flakes prepared by Hummer’s method. These nano-flakes have been successfully reduced while the dynamic of this irradiation process is discussed. The irradiated nano-flakes of graphene oxide have been investigated using X-Ray diffraction, ATR-FTIR and UV-Vis-NIR.