One of the questions about natural phenomena asked in the Hydromethods of the Great West(Taixi shuifa泰西水法;1612)(hereafter TXSF),composed by the Italian Jesuit Sabatino de Ursis with the support of the Chinese offi...One of the questions about natural phenomena asked in the Hydromethods of the Great West(Taixi shuifa泰西水法;1612)(hereafter TXSF),composed by the Italian Jesuit Sabatino de Ursis with the support of the Chinese official Xu Guangqi徐光啟,concerns the causes of sea tides.The idiosyncratic answer given in the TXSF serves as an example for the Jesuit missionaries,strategically motivated approach to the transfer of knowledge through the translation of Western scientific thought into Chinese.From a chronological overview of the attempts made both in the East and in the West to theoretically conceptualize the causes of the cyclical occurrence of ebb and flow,the comparison reveals that despite being based on totally different cosmologies,the related insights were virtually on a par.The aim to nevertheless convince the audience of the TXSF of the superiority of Western sciences resulted in a particular rhetoric and a division of tasks in the composition of the tides paragraph.In order to verify the success of this joint effort of de Ursis and Xu Guangqi,a change of perspective from the transmitter to the receiver side is necessary.Thus,the paper also explores the work's reception in later Chinese works dealing with this topic.展开更多
The flower-like ZnO microstructure was prepared by a straightforward microwave-hydrothermal technique using zinc chloride and arginine solution as reactants. The as-synthesized crystal structure and morphology were ch...The flower-like ZnO microstructure was prepared by a straightforward microwave-hydrothermal technique using zinc chloride and arginine solution as reactants. The as-synthesized crystal structure and morphology were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and the optical properties of the ZnO nanostructure were studied by Raman and photoluminescence （PL） spectra, which confirms the high crystal quality of ZnO microstructure. The as-synthesized ZnO flowers exhibit a significant enhancement of photocatalytic capability toward degrading methyl blue （MB） under UV light, the photodegradation of MB reaches 95.60%, only within 2 h of adding the as-synthesized ZnO in the MB solution under UV irradiation. Furthermore, the photodegradation could be described as the pseudo-first-order kinetics with degradation rate constant of 1.0675-1.6275 h-1, which is relative to the morphology of the structures.展开更多
The Nd-doped TiO2 thin films with higher hydrophilic and photocatalytic activities were prepared on glass slides by an acid-catalyzed sol？gel method. The effects of Nd doping on crystalline phase, surface composition...The Nd-doped TiO2 thin films with higher hydrophilic and photocatalytic activities were prepared on glass slides by an acid-catalyzed sol？gel method. The effects of Nd doping on crystalline phase, surface composition and optical property were investigated by means of techniques such as X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, Fourier transform infrared spectroscopy （FT-IR）, optical contact angle tester and UV-Vis spectroscopy. The results show that Nd doping obviously influences the hydrophilic and photocatalytic activities of TiO2thin films. Nd doping could cause the TiO2 lattice distortion, inhibit phase transition from anatase to rutile, cause red shift of the absorption spectrum edge, produce hydroxyl radicals （·OH）, and accelerate surface hydroxylation, which result in a significant improvement in the hydrophilicity and photoreactivity of Nd-doped TiO2 thin films. When the content of Nd is 0.1% （mass fraction）, TiO2 thin films achieve the smallest grain size （about 15 nm）, and the hydrophilic and photocatalytic activities of TiO2 thin film reach the maximum, the contact angle is only 8.1°, and 92% of methylene blue is finally degraded. Moreover, the modification mechanism of Nd doping was also discussed.展开更多
Flower-like NaY（MoO4）2 particles were synthesized through a microwave-assisted hydrother- mal process followed by a subsequent calcination process. The products were characterized by X-ray diffraction, X-ray photoel...Flower-like NaY（MoO4）2 particles were synthesized through a microwave-assisted hydrother- mal process followed by a subsequent calcination process. The products were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron mi- croscopy. The possible formation mechanism of the flower-like NaY（MoO4）2 precursor was proposed. The NaY（MoO4）2：Eu3＋ phosphors were also prepared and their luminescence properties showed the NaY（MoO4）2：Eu^3＋ materials with the emission peak at 612 nm had potential application as a red phosphor for white light-emitting diodes. Furthermore, the microwave-assisted hydrothermal process followed by a subsequent calcination process could be extended to prepare the other lanthanide molybdates with the flower-like morphology.展开更多
A novel Bi2S3 microsphere was fabricated through one-pot urea-assisted solvothermal method.The synthesized Bi2S3 microsphere was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transf...A novel Bi2S3 microsphere was fabricated through one-pot urea-assisted solvothermal method.The synthesized Bi2S3 microsphere was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transformed infrared spectroscopy(FT-IR)and thermal gravimetric analysis and differential thermal analysis(DTA-TG).Subsequently,the photocatalytic performances of Bi2S3 microsphere were evaluated by photocatalytic degradation of methyl orange(MO)simulation solution under visible-light irradiation.The results show that,Bi2S3 microsphere could be used as a potential cost-efficient catalysis for eliminating of methyl orange from aqueous solutions,whose degradation rate could reach 91.07%within 180 min.Besides,a tentative photocatalytic reaction mechanism was discussed according to the energy band position.Therefore,this work indicated a simplistic approach for the fabrication of visible-light responsive Bi2S3 microsphere photocatalyst,which can be used as a valuable candidate in solar energy conversion and environment pollution treatment.展开更多
Fe-doped BiVO4with hierarchical flower-like structure was prepared via a hydrothermal method using sodium dodecylbenzene sulfonate(SDBS)as structure directing agent.X-ray diffraction(XRD),scanning electron microscope(...Fe-doped BiVO4with hierarchical flower-like structure was prepared via a hydrothermal method using sodium dodecylbenzene sulfonate(SDBS)as structure directing agent.X-ray diffraction(XRD),scanning electron microscope(SEM),transmissionelectron microscope(TEM),high resolution transmission electron microscope(HRTEM),X-ray photoelectron spectroscopy(XPS)and UV-Vis were applied for characterization of the as-prepared samples.The formation mechanism of flower-like structure wasproposed based on the evolution of morphology as a function of hydrothermal time.Fe-doped into substitutional sites of BiVO4effectively improved the migration and separation of photogenerated carrier and enhanced the utilization of visible light.Flower-likeFe-doped BiVO4showed much higher visible-light-driven photocatalytic efficiency for degradation of methyl blue compared withthe pristine BiVO4.And the sample with a Fe/Bi mole ratio of2.5%showed the highest photocatalytic efficiency.展开更多
The controllable synthesis of tantalate K1.9Na0.1Ta2O6·2H2O has been successfully achieved by a two-step technique,namely,the molten salt and hydrothermal methods,at a low temperature. By simply varying the KOH c...The controllable synthesis of tantalate K1.9Na0.1Ta2O6·2H2O has been successfully achieved by a two-step technique,namely,the molten salt and hydrothermal methods,at a low temperature. By simply varying the KOH concentration in the hydrothermal process,K1.9Na0.1Ta2O6·2H2O particles with spherical,cuboctahedral,and durian-like morphologies were synthesized. The photocatalytic activity of the obtained samples for the degradation of rhodamine B was studied under ultraviolet light,which indicates that the photocatalytic properties of the samples are highly dependent on their morphologies. The K1.9Na0.1Ta2O6·2H2O nanospheres,with rough surfaces and the highest specific surface area,exhibit the best performance. The present work provides a unique approach for the controlled synthesis of tantalate photocatalysts,which are difficult to achieve through other synthetic approaches.展开更多
Pure ZnS and Ni^2+-doped ZnS nanorods (Zn1-xNixS, x=0, 0.01, 0.03, 0.05 and 0.07, mole fraction,%) were synthesized by hydrothermal method. The effects of Ni2+ doping on the phase-structure, morphology, elemental comp...Pure ZnS and Ni^2+-doped ZnS nanorods (Zn1-xNixS, x=0, 0.01, 0.03, 0.05 and 0.07, mole fraction,%) were synthesized by hydrothermal method. The effects of Ni2+ doping on the phase-structure, morphology, elemental composition and optical properties of the samples were investigated by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray energy dispersive spectrometry (EDS) and ultraviolet–visible spectroscopy (UV-Vis), respectively. The photocatalytic activity of Zn1-xNixS nanorods was evaluated by the photodegradation of organic dyes Rhodamine B (RhB) in aqueous solution under UV light irradiation. The results show that all samples exhibit wurtzite structure with good crystallization. The morphologies are one-dimensional nanorods with good dispersion, and the distortion of the lattice constant occurs. The band gap of Zn1-xNixS samples is smaller than that of pure ZnS, thus red shift occurs. Ni^2+-doped ZnS nanocrystals can enhance photocatalytic activities for the photodegradation of RhB. Especially, Zn0.97Ni0.03S sample exhibits better photocatalytic performance and photocatalytic stability for the decomposition of RhB.展开更多
Zinc oxide has a large energy gap and thus it has potential application in the field of solar cells by tuning the absorption of sunlight. In order to enhance its absorption of sunlight,dark color zinc oxides have been...Zinc oxide has a large energy gap and thus it has potential application in the field of solar cells by tuning the absorption of sunlight. In order to enhance its absorption of sunlight,dark color zinc oxides have been prepared by traditional hydrothermal method directly using a zinc foil as both source and substrate. We found that we could tune the optical properties of ZnO samples by changing the temperature. In particular, increasing temperature could significantly reduce the reflectivity of solar energy in the visible range. We speculate that the phenomenon is relevant to the sharp cone morphology of the ZnO nanorods grown on the surface of Zn foils, which furthermore enhance refraction and reflection of light in the nanorods. The capacity to improve the light absorption of ZnO may have a bright application in raising the efficiency of solar cells.展开更多
The key concept of spectrum response estimation with commercial software,such as the SESAM software tool,typically includes two main steps:finding a suitable loading spectrum and computing the response amplitude opera...The key concept of spectrum response estimation with commercial software,such as the SESAM software tool,typically includes two main steps:finding a suitable loading spectrum and computing the response amplitude operators(RAOs) subjected to a frequency-specified wave component.In this paper,we propose a nontraditional spectrum response estimation method that uses a numerical representation of the retardation functions.Based on estimated added mass and damping matrices of the structure,we decompose and replace the convolution terms with a series of poles and corresponding residues in the Laplace domain.Then,we estimate the power density corresponding to each frequency component using the improved periodogram method.The advantage of this approach is that the frequency-dependent motion equations in the time domain can be transformed into the Laplace domain without requiring Laplace-domain expressions for the added mass and damping.To validate the proposed method,we use a numerical semi-submerged pontoon from the SESAM.The numerical results show that the responses of the proposed method match well with those obtained from the traditional method.Furthermore,the estimated spectrum also matches well,which indicates its potential application to deep-water floating structures.展开更多
Abstract A real-time photo-realistic rendering algorithm of ocean color is introduced in the paper, which considers the impact of ocean bio-optical model. The ocean bio-optical model mainly involves the phytoplankton,...Abstract A real-time photo-realistic rendering algorithm of ocean color is introduced in the paper, which considers the impact of ocean bio-optical model. The ocean bio-optical model mainly involves the phytoplankton, colored dissolved organic material （CDOM）, inorganic suspended particle, etc., which have different contributionsto absorption and scattering of light. We decompose the emergent light of the ocean surface into the reflected light from the sun and the sky, and the subsurface scattering light. We estab- lish an ocean surface transmission model based on ocean bidirectional reflectance distribution function （BRDF） and the Fresnel law, and this model＇s outputs would be the incident light parameters of subsurface scattering. Using ocean subsurface scattering algorithm combined with bio-optical model, we compute the scattering light emergent radiation in different directions. Then, we blend the re- flection of sunlight and sky light to implement the real-time ocean color rendering in graphics processing unit （GPU）. Finally, we use two kinds of radiance reflectance calculated by Hydrolight radiative transfer model and our algorithm to validate the physical reality of our method, and the results show that our algorithm can achieve real-time highly realistic ocean color scenes.展开更多
We propose a bio-optical inversion model that retrieves the absorption contributions of phytoplankton and colored detrital matter(CDM),as well as the phytoplankton size classes(PSCs),from total minus water absorption ...We propose a bio-optical inversion model that retrieves the absorption contributions of phytoplankton and colored detrital matter(CDM),as well as the phytoplankton size classes(PSCs),from total minus water absorption spectra.The model is based on three-component separation of phytoplankton size structure and a genetic algorithm.The model performance was tested on two independent datasets(the NASA bio-Optical Marine Algorithm Dataset(NOMAD) and the northern South China Sea(NSCS) dataset).The relationships between the estimated and measured values were strongly linear,especially for aCDM(412),and the Root Mean Square Error(RMSE) of the CDM exponential slope(SCDM) was relatively low.Next,the inversion model was directly applied to in-situ total minus water absorption spectra determined by an underwater meter during a cruise in September 2008,to retrieve the phytoplankton size structure in the seawater.By comparing the measured and retrieved chlorophyll a concentrations,we demonstrated that total and size-specific chlorophyll a concentrations could be retrieved by the model with relatively high accuracy.Finally,we applied the bio-optical inversion model to investigate changes in phytoplankton size structure induced by an anti-cyclonic eddy in the NSCS.展开更多
An effective method for isolation of total RNA from pulps of mainly deciduous fruit trees was discussed in this paper. Here we shown that total RNA was successfully isolated from pulps of apple, peach and strawberry, ...An effective method for isolation of total RNA from pulps of mainly deciduous fruit trees was discussed in this paper. Here we shown that total RNA was successfully isolated from pulps of apple, peach and strawberry, but not grape berry via the effective CTAB method modified by ZENG, et al. However, total RNA was isolated from grape berry according to ZENG＇s protocols with a modification including 16% of β-Mercatoethanol and 3% of PVP in extraction buffer, 1/3 （V/V） of 5mol/L potassium acetate （KAC PH4.8） in supernatant. The detection of the isolated total RNA above using ultraviolet spectrophoto-metry, electrophoresis, reverse transcription and RT-PCR shown that the CTAB and its modifications is a preferred method for isolation of high-quality total RNA from fruit pulps.展开更多
Detection of sulfur-oxidizing bacteria has largely been dependent on targeted gene sequencing technology or traditional cell cultivation, which usually takes from days to months to carry out. This clearly does not mee...Detection of sulfur-oxidizing bacteria has largely been dependent on targeted gene sequencing technology or traditional cell cultivation, which usually takes from days to months to carry out. This clearly does not meet the requirements of analysis for time-sensitive samples and/or complicated environmental samples. Since energy-dispersive X-ray spectrometry(EDS) can be used to simultaneously detect multiple elements in a sample, including sulfur, with minimal sample treatment, this technology was applied to detect sulfur-oxidizing bacteria using their high sulfur content within the cell. This article describes the application of scanning electron microscopy imaging coupled with EDS mapping for quick detection of sulfur oxidizers in contaminated environmental water samples, with minimal sample handling. Scanning electron microscopy imaging revealed the existence of dense granules within the bacterial cells, while EDS identified large amounts of sulfur within them. EDS mapping localized the sulfur to these granules. Subsequent 16S rRNA gene sequencing showed that the bacteria detected in our samples belonged to the genus Chromatium, which are sulfur oxidizers. Thus, EDS mapping made it possible to identify sulfur oxidizers in environmental samples based on localized sulfur within their cells, within a short time(within 24 h of sampling). This technique has wide ranging applications for detection of sulfur bacteria in environmental water samples.展开更多
A novel method for on-site determination of trace iron was developed using membrane preconcentration and spectrophotometric detection. Fe（II）-ferrozine complex was reacted with cetyltrimethylammonium bromide （CTAB...A novel method for on-site determination of trace iron was developed using membrane preconcentration and spectrophotometric detection. Fe（II）-ferrozine complex was reacted with cetyltrimethylammonium bromide （CTAB） to form a Fe（II）-ferrozine-CTAB paired compound, which was collected on a membrane by filtration under vacuum. The membrane was immersed in 2 mL of ethanol-nitric acid and the absorbance of the solution measured for quantitative analysis. Various factors affecting the iron collection and determination were investigated. With different sample preconcentration volumes, the range of determination was broadened to 0.5-120 ~tg/L. The detection limit of this method reached 0.19 ktg/L and the recoveries were between 97.2 and 109% when the concentration enrichment was about 45. The relative standard deviation （n = 7） was 1.9% for samples containing 10 ~g/L Fe. Twelve seawater samples were analyzed on-site using the proposed method, and two were also analyzed in inductively coupled plasma mass spectrometry. No significant difference was shown between the two methods by the Student＇s t-test. The method has also been used on-site for iron enrichment experiments with phytoplankton and concluded to be simple, accurate and inexpensive.展开更多
Mg ion-exchanged samples were prepared with acid-washed Shengli lignite.The chemical composition of the ash of the raw sample was determined by X-ray fluorescence.The equilibrium adsorption water contents of samples w...Mg ion-exchanged samples were prepared with acid-washed Shengli lignite.The chemical composition of the ash of the raw sample was determined by X-ray fluorescence.The equilibrium adsorption water contents of samples were determined in a range of relative humidity.The ion-exchange process was characterized by FT-IR,ash content,and p H value.A possible mechanism is proposed for equilibrium adsorption water of ion-exchanged samples at different humidities.The extent of ion-exchange reaction between Mg2+and lignite is controlled by the concentration of Mg2+in Mg SO4solution.The effect of Mg2+on equilibrium adsorption water content varies with relative humidity and content of Mg2+.The factor that controls equilibrium adsorption water content at low relative humidity is water interactions with sorption sites,which are Mg2+–carboxyl group complex.At middle relative humidity capillary force between Mg2+–water clusters Mg+(H2O)nand capillary is more important.At high relative humidity,free water–free water interactions are more significant.展开更多
A beta spectrometric method for the rapid determination of strontium-90 （90Sr） in water samples was developed and tested. 90Sr is extracted directly from the water samples by means of a scintillator cocktail, contai...A beta spectrometric method for the rapid determination of strontium-90 （90Sr） in water samples was developed and tested. 90Sr is extracted directly from the water samples by means of a scintillator cocktail, containing the crown ether dicyclohexano-18-crown-6 as an extracting agent （STRONEX）. Minimal clean-up is necessary when other beta nuclides are present, such as barium-140. These nuclides are eliminated by a barium chromate scavenge, prior to the extraction step. The method presented here allows for the investigation of at least 12 water samples a day and is therefore a suitable tool for emergency analysis.展开更多
ZnSe microspheres were synthesized via a facile hydrothermal method under mild conditions using aqueous zinc nitrate and sodium selenite as raw materials. The effects of hydrothermal temperature, reaction time, concen...ZnSe microspheres were synthesized via a facile hydrothermal method under mild conditions using aqueous zinc nitrate and sodium selenite as raw materials. The effects of hydrothermal temperature, reaction time, concentration of NaOH and amount of hydrazine hydrate on the phase structure, morphology and size of final products were carefully investigated. The phase structures, morphologies and optical properties of the final products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. ZnSe microspheres assembled by average size (about 20 nm) nanocrystals were prepared using 20 mL of 1 mol/L NaOH solution and 10 mL of hydrazine hydrate at 180 °C for 4 h. The results show that the products obtained at low hydrothermal temperature and short reaction time have poor crystallinity and contain impurity phases. The appropriate NaOH concentration and amount of hydrazine hydrate ensure to obtain pure ZnSe with spherical morphology and better luminescence property.展开更多
[Objective] This study aimed to identify red pigment of Panax notoginseng fruits and explore the correlation between pigment content and total saponins of the fruits. [Method] The red pigment of Panax notoginseng frui...[Objective] This study aimed to identify red pigment of Panax notoginseng fruits and explore the correlation between pigment content and total saponins of the fruits. [Method] The red pigment of Panax notoginseng fruits was preliminarily identi- fied with specific color reactions and UV-vis spectra, and the contents of the pigment and total saponins were determined via spectrophotometry. [Result] The red hues of the fruits were contributed by anthocyanins and/or the anthocyanidins. The contents of anthocyanins and total saponins of the fruits both decreased along with thinning of the red hues. The content difference of the anthocyanins in fruits with different red hues reached extremely significant level, but that of total saponins just reached significant level. [Conclusion] The red pigment of P. notoginseng fruits is anthocyanins which are of extremely significant positive correlation with total saponins in contents.展开更多
基金the German Research Foundation for the years 2018 to 2021 and is carried out at the Department of Chinese Studies at Eberhard Karls University of Tubingen under the direction of Prof.Dr.Hans Ulrich Vogel.I thank Prof.Vogel as my supervisor for his dedicated support,and my project colleague Dr.Cao Jin曹晋for her persistent encouragement and great cooperation。
文摘One of the questions about natural phenomena asked in the Hydromethods of the Great West(Taixi shuifa泰西水法;1612)(hereafter TXSF),composed by the Italian Jesuit Sabatino de Ursis with the support of the Chinese official Xu Guangqi徐光啟,concerns the causes of sea tides.The idiosyncratic answer given in the TXSF serves as an example for the Jesuit missionaries,strategically motivated approach to the transfer of knowledge through the translation of Western scientific thought into Chinese.From a chronological overview of the attempts made both in the East and in the West to theoretically conceptualize the causes of the cyclical occurrence of ebb and flow,the comparison reveals that despite being based on totally different cosmologies,the related insights were virtually on a par.The aim to nevertheless convince the audience of the TXSF of the superiority of Western sciences resulted in a particular rhetoric and a division of tasks in the composition of the tides paragraph.In order to verify the success of this joint effort of de Ursis and Xu Guangqi,a change of perspective from the transmitter to the receiver side is necessary.Thus,the paper also explores the work's reception in later Chinese works dealing with this topic.
基金Project (KKSY201205025) supported by Kunming University of Science and Technology Doctoral Scientific Research Fund, ChinaProject (2011408) supported by Testing and Analyzing Foundation of Kunming University of Science and Technology
文摘The flower-like ZnO microstructure was prepared by a straightforward microwave-hydrothermal technique using zinc chloride and arginine solution as reactants. The as-synthesized crystal structure and morphology were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and the optical properties of the ZnO nanostructure were studied by Raman and photoluminescence （PL） spectra, which confirms the high crystal quality of ZnO microstructure. The as-synthesized ZnO flowers exhibit a significant enhancement of photocatalytic capability toward degrading methyl blue （MB） under UV light, the photodegradation of MB reaches 95.60%, only within 2 h of adding the as-synthesized ZnO in the MB solution under UV irradiation. Furthermore, the photodegradation could be described as the pseudo-first-order kinetics with degradation rate constant of 1.0675-1.6275 h-1, which is relative to the morphology of the structures.
基金Projects(51162022,21201098)supported by the National Natural Science Foundation of ChinaProject(GJJ14126)supported by Jiangxi Provincial Education Department,ChinaProject(2012019)supported by the Test Foundation of Nanchang University,China
文摘The Nd-doped TiO2 thin films with higher hydrophilic and photocatalytic activities were prepared on glass slides by an acid-catalyzed sol？gel method. The effects of Nd doping on crystalline phase, surface composition and optical property were investigated by means of techniques such as X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, Fourier transform infrared spectroscopy （FT-IR）, optical contact angle tester and UV-Vis spectroscopy. The results show that Nd doping obviously influences the hydrophilic and photocatalytic activities of TiO2thin films. Nd doping could cause the TiO2 lattice distortion, inhibit phase transition from anatase to rutile, cause red shift of the absorption spectrum edge, produce hydroxyl radicals （·OH）, and accelerate surface hydroxylation, which result in a significant improvement in the hydrophilicity and photoreactivity of Nd-doped TiO2 thin films. When the content of Nd is 0.1% （mass fraction）, TiO2 thin films achieve the smallest grain size （about 15 nm）, and the hydrophilic and photocatalytic activities of TiO2 thin film reach the maximum, the contact angle is only 8.1°, and 92% of methylene blue is finally degraded. Moreover, the modification mechanism of Nd doping was also discussed.
文摘Flower-like NaY（MoO4）2 particles were synthesized through a microwave-assisted hydrother- mal process followed by a subsequent calcination process. The products were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron mi- croscopy. The possible formation mechanism of the flower-like NaY（MoO4）2 precursor was proposed. The NaY（MoO4）2：Eu3＋ phosphors were also prepared and their luminescence properties showed the NaY（MoO4）2：Eu^3＋ materials with the emission peak at 612 nm had potential application as a red phosphor for white light-emitting diodes. Furthermore, the microwave-assisted hydrothermal process followed by a subsequent calcination process could be extended to prepare the other lanthanide molybdates with the flower-like morphology.
基金Projects(21476269,21776319) supported by the National Natural Science Foundation of ChinaProject(2016TP1007) supported by Hunan Provincial Science and Technology Plan Project of China+2 种基金Project(2017J01569) supported by the Natural Science Foundation of Fujian Province,ChinaProject(201710533255) supported by National College Students’ Free Exploration Project of ChinaProject(2017zzts777) supported by Fundamental Research Funds for the Central Universities of Central South University,China
文摘A novel Bi2S3 microsphere was fabricated through one-pot urea-assisted solvothermal method.The synthesized Bi2S3 microsphere was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transformed infrared spectroscopy(FT-IR)and thermal gravimetric analysis and differential thermal analysis(DTA-TG).Subsequently,the photocatalytic performances of Bi2S3 microsphere were evaluated by photocatalytic degradation of methyl orange(MO)simulation solution under visible-light irradiation.The results show that,Bi2S3 microsphere could be used as a potential cost-efficient catalysis for eliminating of methyl orange from aqueous solutions,whose degradation rate could reach 91.07%within 180 min.Besides,a tentative photocatalytic reaction mechanism was discussed according to the energy band position.Therefore,this work indicated a simplistic approach for the fabrication of visible-light responsive Bi2S3 microsphere photocatalyst,which can be used as a valuable candidate in solar energy conversion and environment pollution treatment.
基金Project(51102025)supported by the National Natural Science Foundation of ChinaProject(14JJ7040)supported by Natural Science Foundation of Hunan Province,ChinaProject(2014GH561172)supported by China Torch Program
文摘Fe-doped BiVO4with hierarchical flower-like structure was prepared via a hydrothermal method using sodium dodecylbenzene sulfonate(SDBS)as structure directing agent.X-ray diffraction(XRD),scanning electron microscope(SEM),transmissionelectron microscope(TEM),high resolution transmission electron microscope(HRTEM),X-ray photoelectron spectroscopy(XPS)and UV-Vis were applied for characterization of the as-prepared samples.The formation mechanism of flower-like structure wasproposed based on the evolution of morphology as a function of hydrothermal time.Fe-doped into substitutional sites of BiVO4effectively improved the migration and separation of photogenerated carrier and enhanced the utilization of visible light.Flower-likeFe-doped BiVO4showed much higher visible-light-driven photocatalytic efficiency for degradation of methyl blue compared withthe pristine BiVO4.And the sample with a Fe/Bi mole ratio of2.5%showed the highest photocatalytic efficiency.
基金supported by the National Natural Science Foundation of China(U140319321473261+3 种基金41305112)the Excellent Youth Foundation of Xinjiang Uygur Autonomous Region(2013711004)the CAS "Light of West China" Program(YB201303)the CAS/SAFEA International Partnership Program for Creative Research Teams~~
文摘The controllable synthesis of tantalate K1.9Na0.1Ta2O6·2H2O has been successfully achieved by a two-step technique,namely,the molten salt and hydrothermal methods,at a low temperature. By simply varying the KOH concentration in the hydrothermal process,K1.9Na0.1Ta2O6·2H2O particles with spherical,cuboctahedral,and durian-like morphologies were synthesized. The photocatalytic activity of the obtained samples for the degradation of rhodamine B was studied under ultraviolet light,which indicates that the photocatalytic properties of the samples are highly dependent on their morphologies. The K1.9Na0.1Ta2O6·2H2O nanospheres,with rough surfaces and the highest specific surface area,exhibit the best performance. The present work provides a unique approach for the controlled synthesis of tantalate photocatalysts,which are difficult to achieve through other synthetic approaches.
基金Project(51261015)supported by the National Natural Science Foundation of ChinaProject(1308RJZA238)supported by the Natural Science Foundation of Gansu Province,China
文摘Pure ZnS and Ni^2+-doped ZnS nanorods (Zn1-xNixS, x=0, 0.01, 0.03, 0.05 and 0.07, mole fraction,%) were synthesized by hydrothermal method. The effects of Ni2+ doping on the phase-structure, morphology, elemental composition and optical properties of the samples were investigated by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), X-ray energy dispersive spectrometry (EDS) and ultraviolet–visible spectroscopy (UV-Vis), respectively. The photocatalytic activity of Zn1-xNixS nanorods was evaluated by the photodegradation of organic dyes Rhodamine B (RhB) in aqueous solution under UV light irradiation. The results show that all samples exhibit wurtzite structure with good crystallization. The morphologies are one-dimensional nanorods with good dispersion, and the distortion of the lattice constant occurs. The band gap of Zn1-xNixS samples is smaller than that of pure ZnS, thus red shift occurs. Ni^2+-doped ZnS nanocrystals can enhance photocatalytic activities for the photodegradation of RhB. Especially, Zn0.97Ni0.03S sample exhibits better photocatalytic performance and photocatalytic stability for the decomposition of RhB.
基金supported by the National Natural Science Foundation of China(No.11575187)the National Key Research and Development Program(No.2016YFB0700205)
文摘Zinc oxide has a large energy gap and thus it has potential application in the field of solar cells by tuning the absorption of sunlight. In order to enhance its absorption of sunlight,dark color zinc oxides have been prepared by traditional hydrothermal method directly using a zinc foil as both source and substrate. We found that we could tune the optical properties of ZnO samples by changing the temperature. In particular, increasing temperature could significantly reduce the reflectivity of solar energy in the visible range. We speculate that the phenomenon is relevant to the sharp cone morphology of the ZnO nanorods grown on the surface of Zn foils, which furthermore enhance refraction and reflection of light in the nanorods. The capacity to improve the light absorption of ZnO may have a bright application in raising the efficiency of solar cells.
基金the financial support of the National Natural Science Foundation of China(Nos.5152 2906,51479184,51609219)the Excellent Youth Foundation of Shandong Scientific Committee(No.JQ201512)the Taishan Scholars Program of Shandong Province
文摘The key concept of spectrum response estimation with commercial software,such as the SESAM software tool,typically includes two main steps:finding a suitable loading spectrum and computing the response amplitude operators(RAOs) subjected to a frequency-specified wave component.In this paper,we propose a nontraditional spectrum response estimation method that uses a numerical representation of the retardation functions.Based on estimated added mass and damping matrices of the structure,we decompose and replace the convolution terms with a series of poles and corresponding residues in the Laplace domain.Then,we estimate the power density corresponding to each frequency component using the improved periodogram method.The advantage of this approach is that the frequency-dependent motion equations in the time domain can be transformed into the Laplace domain without requiring Laplace-domain expressions for the added mass and damping.To validate the proposed method,we use a numerical semi-submerged pontoon from the SESAM.The numerical results show that the responses of the proposed method match well with those obtained from the traditional method.Furthermore,the estimated spectrum also matches well,which indicates its potential application to deep-water floating structures.
基金jointly supported by the International Cooperation and Exchange Projects of the National Natural Science Foundation of China (No.61361163001)the National Key Scientific Instrument and Equipment Development Projects of National Natural Science Foundation of China (No.41527901)the National High-Tech R&D Program (863 Program) (No.2013AA09A505)
文摘Abstract A real-time photo-realistic rendering algorithm of ocean color is introduced in the paper, which considers the impact of ocean bio-optical model. The ocean bio-optical model mainly involves the phytoplankton, colored dissolved organic material （CDOM）, inorganic suspended particle, etc., which have different contributionsto absorption and scattering of light. We decompose the emergent light of the ocean surface into the reflected light from the sun and the sky, and the subsurface scattering light. We estab- lish an ocean surface transmission model based on ocean bidirectional reflectance distribution function （BRDF） and the Fresnel law, and this model＇s outputs would be the incident light parameters of subsurface scattering. Using ocean subsurface scattering algorithm combined with bio-optical model, we compute the scattering light emergent radiation in different directions. Then, we blend the re- flection of sunlight and sky light to implement the real-time ocean color rendering in graphics processing unit （GPU）. Finally, we use two kinds of radiance reflectance calculated by Hydrolight radiative transfer model and our algorithm to validate the physical reality of our method, and the results show that our algorithm can achieve real-time highly realistic ocean color scenes.
基金Supported by the Key Projects of the National Natural Science Foundation of China(Nos.41076014,U0933005,41176035,40906022,41206029)
文摘We propose a bio-optical inversion model that retrieves the absorption contributions of phytoplankton and colored detrital matter(CDM),as well as the phytoplankton size classes(PSCs),from total minus water absorption spectra.The model is based on three-component separation of phytoplankton size structure and a genetic algorithm.The model performance was tested on two independent datasets(the NASA bio-Optical Marine Algorithm Dataset(NOMAD) and the northern South China Sea(NSCS) dataset).The relationships between the estimated and measured values were strongly linear,especially for aCDM(412),and the Root Mean Square Error(RMSE) of the CDM exponential slope(SCDM) was relatively low.Next,the inversion model was directly applied to in-situ total minus water absorption spectra determined by an underwater meter during a cruise in September 2008,to retrieve the phytoplankton size structure in the seawater.By comparing the measured and retrieved chlorophyll a concentrations,we demonstrated that total and size-specific chlorophyll a concentrations could be retrieved by the model with relatively high accuracy.Finally,we applied the bio-optical inversion model to investigate changes in phytoplankton size structure induced by an anti-cyclonic eddy in the NSCS.
基金This work was supported by Beijing Natural Science Foundation （No. 6082005） and Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality （No. PXM2007014207）.
文摘An effective method for isolation of total RNA from pulps of mainly deciduous fruit trees was discussed in this paper. Here we shown that total RNA was successfully isolated from pulps of apple, peach and strawberry, but not grape berry via the effective CTAB method modified by ZENG, et al. However, total RNA was isolated from grape berry according to ZENG＇s protocols with a modification including 16% of β-Mercatoethanol and 3% of PVP in extraction buffer, 1/3 （V/V） of 5mol/L potassium acetate （KAC PH4.8） in supernatant. The detection of the isolated total RNA above using ultraviolet spectrophoto-metry, electrophoresis, reverse transcription and RT-PCR shown that the CTAB and its modifications is a preferred method for isolation of high-quality total RNA from fruit pulps.
基金Supported by the Basic Scientific Fund for National Public Research Institutes of China(Nos.GY02-2011T10,2015P07)the Qingdao Talent Program(No.13-CX-20)+1 种基金the National Natural Science Foundation of China(Nos.31100567,41176061)the National Natural Science Foundation for Creative Groups(No.41521064)
文摘Detection of sulfur-oxidizing bacteria has largely been dependent on targeted gene sequencing technology or traditional cell cultivation, which usually takes from days to months to carry out. This clearly does not meet the requirements of analysis for time-sensitive samples and/or complicated environmental samples. Since energy-dispersive X-ray spectrometry(EDS) can be used to simultaneously detect multiple elements in a sample, including sulfur, with minimal sample treatment, this technology was applied to detect sulfur-oxidizing bacteria using their high sulfur content within the cell. This article describes the application of scanning electron microscopy imaging coupled with EDS mapping for quick detection of sulfur oxidizers in contaminated environmental water samples, with minimal sample handling. Scanning electron microscopy imaging revealed the existence of dense granules within the bacterial cells, while EDS identified large amounts of sulfur within them. EDS mapping localized the sulfur to these granules. Subsequent 16S rRNA gene sequencing showed that the bacteria detected in our samples belonged to the genus Chromatium, which are sulfur oxidizers. Thus, EDS mapping made it possible to identify sulfur oxidizers in environmental samples based on localized sulfur within their cells, within a short time(within 24 h of sampling). This technique has wide ranging applications for detection of sulfur bacteria in environmental water samples.
基金Supported by State Key Laboratory of Marine Environmental Science(MEL)Funds(No.MELRI1001)
文摘A novel method for on-site determination of trace iron was developed using membrane preconcentration and spectrophotometric detection. Fe（II）-ferrozine complex was reacted with cetyltrimethylammonium bromide （CTAB） to form a Fe（II）-ferrozine-CTAB paired compound, which was collected on a membrane by filtration under vacuum. The membrane was immersed in 2 mL of ethanol-nitric acid and the absorbance of the solution measured for quantitative analysis. Various factors affecting the iron collection and determination were investigated. With different sample preconcentration volumes, the range of determination was broadened to 0.5-120 ~tg/L. The detection limit of this method reached 0.19 ktg/L and the recoveries were between 97.2 and 109% when the concentration enrichment was about 45. The relative standard deviation （n = 7） was 1.9% for samples containing 10 ~g/L Fe. Twelve seawater samples were analyzed on-site using the proposed method, and two were also analyzed in inductively coupled plasma mass spectrometry. No significant difference was shown between the two methods by the Student＇s t-test. The method has also been used on-site for iron enrichment experiments with phytoplankton and concluded to be simple, accurate and inexpensive.
基金Supported by the National Basic Research Program of China(2012CB214900)the National Natural Science Foundation of China(51274197)+1 种基金the 111 Project(B12030)the Fundamental Research Funds for the Central Universities(2014XT05)
文摘Mg ion-exchanged samples were prepared with acid-washed Shengli lignite.The chemical composition of the ash of the raw sample was determined by X-ray fluorescence.The equilibrium adsorption water contents of samples were determined in a range of relative humidity.The ion-exchange process was characterized by FT-IR,ash content,and p H value.A possible mechanism is proposed for equilibrium adsorption water of ion-exchanged samples at different humidities.The extent of ion-exchange reaction between Mg2+and lignite is controlled by the concentration of Mg2+in Mg SO4solution.The effect of Mg2+on equilibrium adsorption water content varies with relative humidity and content of Mg2+.The factor that controls equilibrium adsorption water content at low relative humidity is water interactions with sorption sites,which are Mg2+–carboxyl group complex.At middle relative humidity capillary force between Mg2+–water clusters Mg+(H2O)nand capillary is more important.At high relative humidity,free water–free water interactions are more significant.
文摘A beta spectrometric method for the rapid determination of strontium-90 （90Sr） in water samples was developed and tested. 90Sr is extracted directly from the water samples by means of a scintillator cocktail, containing the crown ether dicyclohexano-18-crown-6 as an extracting agent （STRONEX）. Minimal clean-up is necessary when other beta nuclides are present, such as barium-140. These nuclides are eliminated by a barium chromate scavenge, prior to the extraction step. The method presented here allows for the investigation of at least 12 water samples a day and is therefore a suitable tool for emergency analysis.
基金Project(13JJ1005)supported by the Natural Science Foundation for Distinguished Young Scholars of Hunan Province,China
文摘ZnSe microspheres were synthesized via a facile hydrothermal method under mild conditions using aqueous zinc nitrate and sodium selenite as raw materials. The effects of hydrothermal temperature, reaction time, concentration of NaOH and amount of hydrazine hydrate on the phase structure, morphology and size of final products were carefully investigated. The phase structures, morphologies and optical properties of the final products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. ZnSe microspheres assembled by average size (about 20 nm) nanocrystals were prepared using 20 mL of 1 mol/L NaOH solution and 10 mL of hydrazine hydrate at 180 °C for 4 h. The results show that the products obtained at low hydrothermal temperature and short reaction time have poor crystallinity and contain impurity phases. The appropriate NaOH concentration and amount of hydrazine hydrate ensure to obtain pure ZnSe with spherical morphology and better luminescence property.
基金Supported by the National Natural Science Foundation of China(No.31060045,31260091)~~
文摘[Objective] This study aimed to identify red pigment of Panax notoginseng fruits and explore the correlation between pigment content and total saponins of the fruits. [Method] The red pigment of Panax notoginseng fruits was preliminarily identi- fied with specific color reactions and UV-vis spectra, and the contents of the pigment and total saponins were determined via spectrophotometry. [Result] The red hues of the fruits were contributed by anthocyanins and/or the anthocyanidins. The contents of anthocyanins and total saponins of the fruits both decreased along with thinning of the red hues. The content difference of the anthocyanins in fruits with different red hues reached extremely significant level, but that of total saponins just reached significant level. [Conclusion] The red pigment of P. notoginseng fruits is anthocyanins which are of extremely significant positive correlation with total saponins in contents.
