OBJECTIVE Analysis of traditional Chinese medicinal(TCM)supplements has always been a laborious task,particularly in the case of multi-ingredient formulations.Traditionally,herbal extracts are analyzed using one or fe...OBJECTIVE Analysis of traditional Chinese medicinal(TCM)supplements has always been a laborious task,particularly in the case of multi-ingredient formulations.Traditionally,herbal extracts are analyzed using one or few markers compounds.In the recent years,however,pharmaceutical companies are introducing health supplements of TCM ingredients to cater to the needs of consumers in the fast-paced society in this age.As such,new problems arise in the aspects of composition identification as well as quality analysis.In most cases of products or supplements formulated with multiple TCM herbs,the chemical composition and nature of each raw material differs greatly from the others in the formulation.This results in a requirement for individual analytical processes in order to identify the marker compounds in the various botanicals.The aim of this study is to establish a rapid and low cost analytical approach using high performance thin layer chromatography(HPTLC)for the analysis of 3 key components of the LAC Liver Protector,a supplement with TCM formulation aimed at improving liver health.METHODS The TCM herbs were extracted with methods derived from Chinese Pharmacopeia standards.The herbal extracts were then applied to HPTLC plates using CAMAG Linomat 5 and developed using fully saturated twin-trough chromatographic chambers.The developed plates were derivatized and documented with CAMAG TLC Visualizer.The images were processed with CAMAG winCATS software to calculate the Rf values and confirm the presence of key constituents of the herbs.RESULTS The 3 key components of LAC Liver Protector product,namely Radix notoginseng,Rhizoma alismatis and Radix paeoniae alba/rubra were identified in all 6 batches of products tested.CONCLUSION With the increasing trend of small and medium-sized enterprises(SMEs)bringing natural products and health supplements into the market,it is crucial that the qualities of both raw materials and end products be well-assured for the protection of consumers.With the technology of HPTLC,science can be incorporated to help SMEs with their quality control,thereby ensuring product quality.展开更多
Traditional cooling systems have been posing a significant challenge to the global energy crisis and climate change due to the high energy consumption of the cooling process.In recent years,the emerging daytime radiat...Traditional cooling systems have been posing a significant challenge to the global energy crisis and climate change due to the high energy consumption of the cooling process.In recent years,the emerging daytime radiative cooling provides a promising solution to address the bottleneck of traditional cooling technology by passively dissipating heat radiation to outer space without any energy consumption through the atmospheric transparency window(8~13μm).Whereas its stringent optical criteria require sophisticated and high cost fabrication producers,which hinders the applicability of radiative cooling technology.Many efforts have been devoted to develop high-efficiency and low-cost daytime radiative cooling technologies for practical application,including the nanophotonics based artificial strategy and bioinspired strategy.In order to systematically summarize the development and latest advance of daytime radiative cooling to help developing the most promising approach,here in this paper we will review and compare the two typical strategies on exploring the prospect approach for applicable radiative cooling technology.We will firstly sketch the fundamental of radiative cooling and summarize the common methods for construction radiative cooling devices.Then we will put an emphasis on the summarization and comparison of the two strategies for designing the radiative cooling device,and outlook the prospect and extending application of the daytime radiative cooling technology.展开更多
In this work, an analytical model is presented to simulate the combustion process of organic dust with considering radiative heat loss effect in counterflow configuration. A thermal model has been generated to estimat...In this work, an analytical model is presented to simulate the combustion process of organic dust with considering radiative heat loss effect in counterflow configuration. A thermal model has been generated to estimate the flame propagation speed in various dust concentrations. The structure of premixed flame in a symmetric configuration, containing uniformly distributed volatile fuel particles, with nonunity Lewis number is examined with strain rate issue. The flame structure is divided into six zones: first heating, drying, second heating, volatile evaporation, reaction and post-flame zones. At first, the governing equations of lycopodium combustion dust particles are written for each zone. Finally, boundary conditions and matching conditions are applied for each zone in order to solve the differential equations. The purpose of this article is to analyze radiation heat transfer on lycopodium flame propagation dust particles and characteristics to check the effect of parameters on combustion.展开更多
The radiative properties(absorptance, reflectance, and transmittance) of deep slits with five nanoscale slit profile variations at the transverse magnetic wave incidence were numerically investigated by employing the ...The radiative properties(absorptance, reflectance, and transmittance) of deep slits with five nanoscale slit profile variations at the transverse magnetic wave incidence were numerically investigated by employing the finite difference time domain method. For slits with attached features, their radiative properties can be much different due to the modified cavity geometry and dangled structures, even at wavelengths between 3 and 15 μm. The shifts of cavity resonance excitation result in higher transmittance through narrower slits at specific wavelengths and resonance modes are confirmed with the electromagnetic fields. Opposite roles possibly played by features in increasing or decreasing absorptance are determined by the feature position and demonstrated by Poynting vectors. Correlations among all properties of a representative slit array and the slit density are also comprehensively studied. When multiple slit types coexist in an array(complex slits), a wide-band transmittance or absorptance enhancement is feasible by merging spectral peaks contributed from each type of slits distinctively. Discrepancy among infrared properties of four selected slit combinations is explained while effects of slit density are also discussed.展开更多
An overall vector radiative transfer theory was developed for numerical modeling, in both active and passive microwave remote sensing. The Theory and approaches are briefly summerized.To quantitatively understand scat...An overall vector radiative transfer theory was developed for numerical modeling, in both active and passive microwave remote sensing. The Theory and approaches are briefly summerized.To quantitatively understand scattering and thermal emission from targets in active and passive remote sensing, we have developed an overall vector radiative transfer theory for a set of theoretical models of discrete scatterer and continuous random media for the earth terrain (wet soil, vegetation, snow, sea-ice, etc.) and atmosphere, and numerical approaches for simulation, data analysis, and parameter sensitivity test. Our numerical results favorably agreed with experimental data in microwave re mote sensing of various earth surfaces. Main approaches are briefly summerized herewith.展开更多
文摘OBJECTIVE Analysis of traditional Chinese medicinal(TCM)supplements has always been a laborious task,particularly in the case of multi-ingredient formulations.Traditionally,herbal extracts are analyzed using one or few markers compounds.In the recent years,however,pharmaceutical companies are introducing health supplements of TCM ingredients to cater to the needs of consumers in the fast-paced society in this age.As such,new problems arise in the aspects of composition identification as well as quality analysis.In most cases of products or supplements formulated with multiple TCM herbs,the chemical composition and nature of each raw material differs greatly from the others in the formulation.This results in a requirement for individual analytical processes in order to identify the marker compounds in the various botanicals.The aim of this study is to establish a rapid and low cost analytical approach using high performance thin layer chromatography(HPTLC)for the analysis of 3 key components of the LAC Liver Protector,a supplement with TCM formulation aimed at improving liver health.METHODS The TCM herbs were extracted with methods derived from Chinese Pharmacopeia standards.The herbal extracts were then applied to HPTLC plates using CAMAG Linomat 5 and developed using fully saturated twin-trough chromatographic chambers.The developed plates were derivatized and documented with CAMAG TLC Visualizer.The images were processed with CAMAG winCATS software to calculate the Rf values and confirm the presence of key constituents of the herbs.RESULTS The 3 key components of LAC Liver Protector product,namely Radix notoginseng,Rhizoma alismatis and Radix paeoniae alba/rubra were identified in all 6 batches of products tested.CONCLUSION With the increasing trend of small and medium-sized enterprises(SMEs)bringing natural products and health supplements into the market,it is crucial that the qualities of both raw materials and end products be well-assured for the protection of consumers.With the technology of HPTLC,science can be incorporated to help SMEs with their quality control,thereby ensuring product quality.
文摘Traditional cooling systems have been posing a significant challenge to the global energy crisis and climate change due to the high energy consumption of the cooling process.In recent years,the emerging daytime radiative cooling provides a promising solution to address the bottleneck of traditional cooling technology by passively dissipating heat radiation to outer space without any energy consumption through the atmospheric transparency window(8~13μm).Whereas its stringent optical criteria require sophisticated and high cost fabrication producers,which hinders the applicability of radiative cooling technology.Many efforts have been devoted to develop high-efficiency and low-cost daytime radiative cooling technologies for practical application,including the nanophotonics based artificial strategy and bioinspired strategy.In order to systematically summarize the development and latest advance of daytime radiative cooling to help developing the most promising approach,here in this paper we will review and compare the two typical strategies on exploring the prospect approach for applicable radiative cooling technology.We will firstly sketch the fundamental of radiative cooling and summarize the common methods for construction radiative cooling devices.Then we will put an emphasis on the summarization and comparison of the two strategies for designing the radiative cooling device,and outlook the prospect and extending application of the daytime radiative cooling technology.
文摘In this work, an analytical model is presented to simulate the combustion process of organic dust with considering radiative heat loss effect in counterflow configuration. A thermal model has been generated to estimate the flame propagation speed in various dust concentrations. The structure of premixed flame in a symmetric configuration, containing uniformly distributed volatile fuel particles, with nonunity Lewis number is examined with strain rate issue. The flame structure is divided into six zones: first heating, drying, second heating, volatile evaporation, reaction and post-flame zones. At first, the governing equations of lycopodium combustion dust particles are written for each zone. Finally, boundary conditions and matching conditions are applied for each zone in order to solve the differential equations. The purpose of this article is to analyze radiation heat transfer on lycopodium flame propagation dust particles and characteristics to check the effect of parameters on combustion.
基金Project(N130402006)supported by Fundamental Research Funds for the Central Universities,ChinaProject(51476024)supported by the National Natural Science Foundation of China
文摘The radiative properties(absorptance, reflectance, and transmittance) of deep slits with five nanoscale slit profile variations at the transverse magnetic wave incidence were numerically investigated by employing the finite difference time domain method. For slits with attached features, their radiative properties can be much different due to the modified cavity geometry and dangled structures, even at wavelengths between 3 and 15 μm. The shifts of cavity resonance excitation result in higher transmittance through narrower slits at specific wavelengths and resonance modes are confirmed with the electromagnetic fields. Opposite roles possibly played by features in increasing or decreasing absorptance are determined by the feature position and demonstrated by Poynting vectors. Correlations among all properties of a representative slit array and the slit density are also comprehensively studied. When multiple slit types coexist in an array(complex slits), a wide-band transmittance or absorptance enhancement is feasible by merging spectral peaks contributed from each type of slits distinctively. Discrepancy among infrared properties of four selected slit combinations is explained while effects of slit density are also discussed.
基金The Project supported by National National Science FoundationYing Tung Education Foundation
文摘An overall vector radiative transfer theory was developed for numerical modeling, in both active and passive microwave remote sensing. The Theory and approaches are briefly summerized.To quantitatively understand scattering and thermal emission from targets in active and passive remote sensing, we have developed an overall vector radiative transfer theory for a set of theoretical models of discrete scatterer and continuous random media for the earth terrain (wet soil, vegetation, snow, sea-ice, etc.) and atmosphere, and numerical approaches for simulation, data analysis, and parameter sensitivity test. Our numerical results favorably agreed with experimental data in microwave re mote sensing of various earth surfaces. Main approaches are briefly summerized herewith.
