[ Objective] The aim was to establish a method for the determination of Rhodamine B in food by HPLC-UV. [ Metkod] Rhodamine B was extracted with acetone/hexane from food samples. After concentrated and purified by alu...[ Objective] The aim was to establish a method for the determination of Rhodamine B in food by HPLC-UV. [ Metkod] Rhodamine B was extracted with acetone/hexane from food samples. After concentrated and purified by alumina cartridge, the Rhodamine B content in the food was determined by using high performance liquid chromatography with ultraviolet visible detector. [ Result] Within tile concentration range of 0.005 - 2.000 mg/kg, the peak area of Rhodamine B presented good linear relation with the concentration, and the related coefficient was 0.999 98. With high average recovery rate, the detection limit of the method was 0.005 mg/kg[ Concision] It is a fast and accurate method with high sensitivity to detect Rhodamine B in food.展开更多
It has been more than half a century since the release of the first Shimadzu UV-VIS （UV-visible） spectrophotometer QB-50 in 1952, and during this time more than 160,000 UV-VIS spectrometers have been produced and in...It has been more than half a century since the release of the first Shimadzu UV-VIS （UV-visible） spectrophotometer QB-50 in 1952, and during this time more than 160,000 UV-VIS spectrometers have been produced and installed in a wide variety of different applications. A lot of technical innovations have been implemented to improve the performance and significantly reduce the stray light levels. The latest innovation during development of sophisticated spectrophotometers is based on a new holographic exposure method and optimized etching process which has made it possible to produce both high-efficient and exceptionally low stray light gratings. These LO-RAY-LIGH~ gratings have guaranteed values of stray light at the intermediate position between zero-order and first-order lights. The values are measured by Shimadzu＇s laser stray-light-measuring system. The latest development in the series of UV-VIS spectrophotometers is the UV-2700 which is a true double beam double monochromator system in a compact design for high-precision spectral analysis of a wide range of samples including organic and inorganic compounds, biological samples, optical materials and photovoltaics. The high performance optical system is designed with ＂LO-RAY-LIGH＂ diffraction gratings, featuring highest efficiency and exceptionally low stray light. The spectrophotometer operates in the wavelength range from 185 nm to 900 nm and allows highly sophisticated applications such as direct measurement of high density samples up to 8 absorbance units without dilution.展开更多
One of the essential controls on the microwave thermal emissions(MTE) of the lunar regolith is the abundance of Fe O and TiO_2, known as the(Fe O+Ti O_2) abundance(FTA). In this paper, a radiative transfer simulation ...One of the essential controls on the microwave thermal emissions(MTE) of the lunar regolith is the abundance of Fe O and TiO_2, known as the(Fe O+Ti O_2) abundance(FTA). In this paper, a radiative transfer simulation is employed first to study the change in the brightness temperature(T_B) with FTA under a range of frequencies and surface temperatures. Then, we analyze the influence of FTA on the MTE of the lunar regolith using microwave sounder(CELMS) data from the Chang'E-2 lunar orbiter, Clementine UV-VIS data, and lunar samples recovered from the Apollo and Surveyor projects. We conclude that:(1) FTA strongly influences the MTE of the lunar regolith, but it is not the decisive control, and(2) FTA decreases slightly with depth. This research plays an essential role in appropriately inverting CELMS data to obtain lunar regolith parameters.展开更多
The green-emitting fluorescent powders of nano Y2O3：Er^3＋ were fabricated by the coprecipitation method. The X-ray diffrac- tion pattern shows that as-prepared Y2O3：Er^3＋ is the cubic phase crystal with a grain si...The green-emitting fluorescent powders of nano Y2O3：Er^3＋ were fabricated by the coprecipitation method. The X-ray diffrac- tion pattern shows that as-prepared Y2O3：Er^3＋ is the cubic phase crystal with a grain size of about 30 nm. The UV-Vis spec- trum indicates Y^O3：Er^3＋ exhibits five ultraviolet visible absorption peaks at 365, 377, 489, 521 and 652 nm respectively. Meanwhile, the fluorescence spectra of Y2O3：Er^3＋ display four emission peaks at 522, 537, 550 and 562 nm at the excitation of 365,377 and 521 nm, respectively. The green-emitting fluorescent mechanism of Y2O3：Er^3＋ is proposed as well. Additionally, the temperature dependence of fluorescence properties and metal Ag fluorescence enhancement effect are investigated. Results show that increasing the annealing temperature and metal Ag doping both can enhance the fluorescence intensity. The maxi- mum enhancement is 87.5% after Ag is doped.展开更多
Semi-empirical AM1 and ZINDO/S,as well as density function theory(DFT)method B3LYP/6-31G(d)quantum chemical calculations were carried out to study the electronic structures and optical properties of poly(p-phenylene v...Semi-empirical AM1 and ZINDO/S,as well as density function theory(DFT)method B3LYP/6-31G(d)quantum chemical calculations were carried out to study the electronic structures and optical properties of poly(p-phenylene vinylene)derivatives(PPVs)with 10 and 11 phenylene rings in the backbone.The calculations suggest that the assembly of alternate incorporation of CN and alkoxy substituted phenylene rings in the PPV backbone could be a good way to construct organic semiconductors with low HOMO/LUMO energy band-gaps.The effect of the end-group on the electronic structures and optical properties of the conjugated polymer was investigated by the calculated UV-Vis and UPS spectra.It was demonstrated that the aldehyde and phosphate end-groups have limited effects on the photophysical properties in the UV-Visible range.展开更多
The Cu2 Zn Sn S4(CZTS) powders are successfully synthesized by using Zn S and Cu2 Sn S3 as raw materials directly without any intermediate phase at 450 °C for 3 h in Ar atmosphere.The crystalline structure,morpho...The Cu2 Zn Sn S4(CZTS) powders are successfully synthesized by using Zn S and Cu2 Sn S3 as raw materials directly without any intermediate phase at 450 °C for 3 h in Ar atmosphere.The crystalline structure,morphology and optical properties of the CZTS powders are characterized by X-ray diffraction(XRD),Raman spectrum,field emission scanning electron microscopy(FESEM) and ultraviolet-visible(UV-vis) spectrophotometer,respectively.The results show that the band gap of the obtained CZTS is 1.53 e V.The CZTS film is fabricated by spin coating a mixture of CZTS powders and novolac resin with a weight percentage of 30%.The photoelectrical properties of such CZTS films are measured,and the results show an incident light density of 100 m W·cm-2 with the bias voltage of 0.40 V,and the photocurrent density can approach 9.80×10-5 A·cm2 within 50 s,giving an on/off switching ratio of 1.64.展开更多
文摘[ Objective] The aim was to establish a method for the determination of Rhodamine B in food by HPLC-UV. [ Metkod] Rhodamine B was extracted with acetone/hexane from food samples. After concentrated and purified by alumina cartridge, the Rhodamine B content in the food was determined by using high performance liquid chromatography with ultraviolet visible detector. [ Result] Within tile concentration range of 0.005 - 2.000 mg/kg, the peak area of Rhodamine B presented good linear relation with the concentration, and the related coefficient was 0.999 98. With high average recovery rate, the detection limit of the method was 0.005 mg/kg[ Concision] It is a fast and accurate method with high sensitivity to detect Rhodamine B in food.
文摘It has been more than half a century since the release of the first Shimadzu UV-VIS （UV-visible） spectrophotometer QB-50 in 1952, and during this time more than 160,000 UV-VIS spectrometers have been produced and installed in a wide variety of different applications. A lot of technical innovations have been implemented to improve the performance and significantly reduce the stray light levels. The latest innovation during development of sophisticated spectrophotometers is based on a new holographic exposure method and optimized etching process which has made it possible to produce both high-efficient and exceptionally low stray light gratings. These LO-RAY-LIGH~ gratings have guaranteed values of stray light at the intermediate position between zero-order and first-order lights. The values are measured by Shimadzu＇s laser stray-light-measuring system. The latest development in the series of UV-VIS spectrophotometers is the UV-2700 which is a true double beam double monochromator system in a compact design for high-precision spectral analysis of a wide range of samples including organic and inorganic compounds, biological samples, optical materials and photovoltaics. The high performance optical system is designed with ＂LO-RAY-LIGH＂ diffraction gratings, featuring highest efficiency and exceptionally low stray light. The spectrophotometer operates in the wavelength range from 185 nm to 900 nm and allows highly sophisticated applications such as direct measurement of high density samples up to 8 absorbance units without dilution.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41371332 & 41590851)the Fundamental Research Funds for the Central Universities (Grant No. JCKY-QKJC23)the Science and Technology Development Fund of Macao (Grant No. 110/2014/A3)
文摘One of the essential controls on the microwave thermal emissions(MTE) of the lunar regolith is the abundance of Fe O and TiO_2, known as the(Fe O+Ti O_2) abundance(FTA). In this paper, a radiative transfer simulation is employed first to study the change in the brightness temperature(T_B) with FTA under a range of frequencies and surface temperatures. Then, we analyze the influence of FTA on the MTE of the lunar regolith using microwave sounder(CELMS) data from the Chang'E-2 lunar orbiter, Clementine UV-VIS data, and lunar samples recovered from the Apollo and Surveyor projects. We conclude that:(1) FTA strongly influences the MTE of the lunar regolith, but it is not the decisive control, and(2) FTA decreases slightly with depth. This research plays an essential role in appropriately inverting CELMS data to obtain lunar regolith parameters.
基金supported by the National Natural Science Foundation of China (Grant No. 21176199)the Research Fund for the Doctoral Program of Higher Education (Grant No. 20096101110013)+2 种基金the Industrialization Cultivation Item of Shaanxi Province Educational Department(Grant No. 2011JG05)the Natural Science Foundation of Shaanxi Province (Grant No. 2011JM1001)the Education and Teaching Reform Project of Northwest University (Grant No. Fjg10004)
文摘The green-emitting fluorescent powders of nano Y2O3：Er^3＋ were fabricated by the coprecipitation method. The X-ray diffrac- tion pattern shows that as-prepared Y2O3：Er^3＋ is the cubic phase crystal with a grain size of about 30 nm. The UV-Vis spec- trum indicates Y^O3：Er^3＋ exhibits five ultraviolet visible absorption peaks at 365, 377, 489, 521 and 652 nm respectively. Meanwhile, the fluorescence spectra of Y2O3：Er^3＋ display four emission peaks at 522, 537, 550 and 562 nm at the excitation of 365,377 and 521 nm, respectively. The green-emitting fluorescent mechanism of Y2O3：Er^3＋ is proposed as well. Additionally, the temperature dependence of fluorescence properties and metal Ag fluorescence enhancement effect are investigated. Results show that increasing the annealing temperature and metal Ag doping both can enhance the fluorescence intensity. The maxi- mum enhancement is 87.5% after Ag is doped.
基金supported by the National Natural Science Foundation of China(21274065,20804020,21001065)National Basic Research Program of China(2009CB930601)+1 种基金Natural Science Foundation of Jiangsu Province(BK2011751)A project funded by the priority academic program development of Jiangsu higher education institutions,and Scientific Re-search Foundation of Nanjing University of Posts and Telecommunications(NY210017,NY210046)
文摘Semi-empirical AM1 and ZINDO/S,as well as density function theory(DFT)method B3LYP/6-31G(d)quantum chemical calculations were carried out to study the electronic structures and optical properties of poly(p-phenylene vinylene)derivatives(PPVs)with 10 and 11 phenylene rings in the backbone.The calculations suggest that the assembly of alternate incorporation of CN and alkoxy substituted phenylene rings in the PPV backbone could be a good way to construct organic semiconductors with low HOMO/LUMO energy band-gaps.The effect of the end-group on the electronic structures and optical properties of the conjugated polymer was investigated by the calculated UV-Vis and UPS spectra.It was demonstrated that the aldehyde and phosphate end-groups have limited effects on the photophysical properties in the UV-Visible range.
基金supported by the Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials
文摘The Cu2 Zn Sn S4(CZTS) powders are successfully synthesized by using Zn S and Cu2 Sn S3 as raw materials directly without any intermediate phase at 450 °C for 3 h in Ar atmosphere.The crystalline structure,morphology and optical properties of the CZTS powders are characterized by X-ray diffraction(XRD),Raman spectrum,field emission scanning electron microscopy(FESEM) and ultraviolet-visible(UV-vis) spectrophotometer,respectively.The results show that the band gap of the obtained CZTS is 1.53 e V.The CZTS film is fabricated by spin coating a mixture of CZTS powders and novolac resin with a weight percentage of 30%.The photoelectrical properties of such CZTS films are measured,and the results show an incident light density of 100 m W·cm-2 with the bias voltage of 0.40 V,and the photocurrent density can approach 9.80×10-5 A·cm2 within 50 s,giving an on/off switching ratio of 1.64.
