We re-explain the Weyl quantization scheme by virtue of the technique of integration within Weyl orderedproduct of operators,i.e.,the Weyl correspondence rule can be reconstructed by classical functions' Fourier t...We re-explain the Weyl quantization scheme by virtue of the technique of integration within Weyl orderedproduct of operators,i.e.,the Weyl correspondence rule can be reconstructed by classical functions' Fourier transfor-mation followed by an inverse Fourier transformation within Weyl ordering of operators.As an application of thisreconstruction,we derive the quantum operator coresponding to the angular spectrum amplitude of a spherical wave.展开更多
Herein, novel plasmonic Bi metal in situ deposited in reduced Ti O2 microspheres(Bi@R-Ti O2) are fabricated via a bimetallic MOF-derived synthesized strategy by adjusting the synthesizing temperature. Different charac...Herein, novel plasmonic Bi metal in situ deposited in reduced Ti O2 microspheres(Bi@R-Ti O2) are fabricated via a bimetallic MOF-derived synthesized strategy by adjusting the synthesizing temperature. Different characterization techniques, including XRD, SEM, TEM, XPS, DRS, PL, EIS, and photocurrent generation, are performed to investigate the structural and optical properties of the as-prepared samples. The results indicate that the Bi particles are generated inside and outside of reduced Ti O2 microspheres via the reduction of Ti4+ and Bi3+ by ethylene glycol. When the annealing temperature is controlled at 300 o C, the corresponding Bi@R-Ti O2-300 sample with an appropriate amount of Bi nanoparticles exhibits the highest full solar spectrum photocatalytic oxygen evolution activity(4728.709 μmol h–1 g–1), which is 5.9 and 9.5 times higher than that of pure Ti O2 and Bi-Ti bimetal organic frameworks(Bi-Ti-MOFs). Several reasons are suggested for the above results:(1) Bi metal behaves as an "electron acceptor" to accelerate the charge carrier transfer from Ti O2 to Bi;(2) The surface plasmon resonance effect of loaded metallic Bi particles can enhance the visible and NIR light absorption capacity;(3) The generation of Ti3+ further narrows the band gap of TiO2.展开更多
Water vapor in the earth′s upper atmosphere plays a crucial role in the radiative balance, hydrological process, and climate change. Based on the latest moderate-resolution imaging spectroradiometer(MODIS) data, this...Water vapor in the earth′s upper atmosphere plays a crucial role in the radiative balance, hydrological process, and climate change. Based on the latest moderate-resolution imaging spectroradiometer(MODIS) data, this study probes the spatio-temporal variations of global water vapor content in the past decade. It is found that overall the global water vapor content declined from 2003 to 2012(slope b = –0.0149, R = 0.893, P = 0.0005). The decreasing trend over the ocean surface(b = –0.0170, R = 0.908, P = 0.0003) is more explicit than that over terrestrial surface(b = –0.0100, R = 0.782, P = 0.0070), more significant over the Northern Hemisphere(b = –0.0175, R = 0.923, P = 0.0001) than that over the Southern Hemisphere(b = –0.0123, R = 0.826, P = 0.0030). In addition, the analytical results indicate that water vapor content are decreasing obviously between latitude of 36°N and 36°S(b = 0.0224, R = 0.892, P = 0.0005), especially between latitude of 0°N and 36°N(b = 0.0263, R = 0.931, P = 0.0001), while the water vapor concentrations are increasing slightly in the Arctic regions(b = 0.0028, R = 0.612, P = 0.0590). The decreasing and spatial variation of water vapor content regulates the effects of carbon dioxide which is the main reason of the trend in global surface temperatures becoming nearly flat since the late 1990 s. The spatio-temporal variations of water vapor content also affect the growth and spatial distribution of global vegetation which also regulates the global surface temperature change, and the climate change is mainly caused by the earth's orbit position in the solar and galaxy system. A big data model based on gravitational-magmatic change with the solar or the galactic system is proposed to be built for analyzing how the earth's orbit position in the solar and galaxy system affects spatio-temporal variations of global water vapor content, vegetation and temperature at large spatio-temporal scale. This comprehensive examination of water vapor changes promises a holistic understanding of the global climate change and potential underlying mechanisms.展开更多
In this paper,a thin cloud removal method was put forward based on the linear relationships between the thin cloud reflectance in the channels from 0.4 μm to 1.0 μm and 1.38 μm.Channels of 0.66 μm,0.86 μm and 1....In this paper,a thin cloud removal method was put forward based on the linear relationships between the thin cloud reflectance in the channels from 0.4 μm to 1.0 μm and 1.38 μm.Channels of 0.66 μm,0.86 μm and 1.38 μm were chosen to extract the water body information under the thin cloud.Two study cases were selected to validate the thin cloud removal method.One case was applied with the Earth Observation System Moderate Resolution Imaging Spectroradiometer(EOS/MODIS) data,and the other with the Medium Resolution Spectral Imager(MERSI) and Visible and Infrared Radiometer(VIRR) data from Fengyun-3A(FY-3A).The test results showed that thin cloud removal method did not change the reflectivity of the ground surface under the clear sky.To the area contaminated by the thin cloud,the reflectance decreased to be closer to the reference reflectance under the clear sky after the thin cloud removal.The spatial distribution of the water body area could not be extracted before the thin cloud removal,while water information could be easily identified by using proper near infrared channel threshold after removing the thin cloud.The thin cloud removal method could improve the image quality and water body extraction precision effectively.展开更多
The suspension polymerization with two organic phases was adopted to prepare spherical hyper- crosslinked resin by self-polycondensation of 4,4'-bis-(chloromethyl)- 1, 1'-biphenyl (CMB). The chemical structure,m...The suspension polymerization with two organic phases was adopted to prepare spherical hyper- crosslinked resin by self-polycondensation of 4,4'-bis-(chloromethyl)- 1, 1'-biphenyl (CMB). The chemical structure,morphology and pore characteristics of the novel spherical resin were characterized with Fourier transform infrared spectroscopy (FTIR), micrograph and Brunauer-Emmett-Teller (BET). It is found that the suspension system and stirring speed impose a great influence upon the regularity and size distribution of hypercrosslinked beads. To prepare CMB resin beads with diameter of about 300 μm, the optimal condition is as follows: stirring speed 300 r·min^-1, and the volume ratio of the two organic phases (nitrobenzene/dimethyl silicon oil) 1 : 5. After the self-polycondensation and sqccedent post-crosslinking of CMB monomer, the spherical adsorbent presents high spec^al surface area (1190 m^2· g^-1) and abundant pore^volume (0.714 cm^3· g^-1), and could be potentially applied qn the adsorption of various organic molecules and synthesis of porous ion exchanger.展开更多
Black carbon (BC) aerosols can strongly absorb solar radiation in very broad spectral wavebands, from the visible to the infrared. As a potential factor contributing to global warming, BC aerosols not only directly ...Black carbon (BC) aerosols can strongly absorb solar radiation in very broad spectral wavebands, from the visible to the infrared. As a potential factor contributing to global warming, BC aerosols not only directly change the radiation balance of the earth-atmosphere system, but also indirectly affect global or regional climate by acting as cloud conden- sation nuclei or ice nuclei to alter cloud mierophysical properties. Here, recent progresses in the studies of radiative forcing due to BC and its climate effects are reviewed. The uncertainties in current researches are discussed and some suggestions are provided for future investigations.展开更多
Antibacterial activity of boron-doped TiO2(B/TiO2) nano-materials under visible light irradiation and in the dark was investigated. A simple sol-gel method was used to synthesize TiO2 nano-materials. X-ray diffraction...Antibacterial activity of boron-doped TiO2(B/TiO2) nano-materials under visible light irradiation and in the dark was investigated. A simple sol-gel method was used to synthesize TiO2 nano-materials. X-ray diffraction pattern of B/TiO2 nano-materials represents the diffraction peaks relating to the crystal planes of TiO2(anatase and rutile). X-ray photoelectron spectroscopy result shows that part of boron ions incorporates into TiO2 lattice to form a possible chemical environment like Ti O B and the rest exist in the form of B2O3. The study on antibacterial effect of B/TiO2 nano-materials on fungal Candida albicans(ATCC10231), Gram-negative Escherichia coli(ATCC25922) and Gram-positive Staphylococcus aureus(ATCC6538) shows that the antibacterial action is more significant on Candida albicans than on Escherichia coli and Staphylococcus aureus. Under visible light irradiation, the antibacterial activity is superior to that in the dark.展开更多
An efficient method to track the carrier frequency which is recommended to use in low earth orbit(LEO) direct-sequence spread-spectrum(DS/SS) communication system is given. The carrier frequency drifts quicker in LEO ...An efficient method to track the carrier frequency which is recommended to use in low earth orbit(LEO) direct-sequence spread-spectrum(DS/SS) communication system is given. The carrier frequency drifts quicker in LEO DS/SS communication system, its tracking problem becomes much more important especially in digital receiver with the limits of physical shape and power. Under the condition of coarse carrier frequency synchronization, a digital tracking method based on least square method(LSM) is proved to be a quick, simple and efficient method. Numerical results and charts are given.展开更多
A Local Ensemble Transform Kalman Filter assimilation system has been implemented into an aerosol-coupled global nonhydrostatic model to simulate the aerosol mass concentration and aerosol optical properties of 3 dese...A Local Ensemble Transform Kalman Filter assimilation system has been implemented into an aerosol-coupled global nonhydrostatic model to simulate the aerosol mass concentration and aerosol optical properties of 3 desert sites(Ansai, Fukang, Shapotou) in northwestern China. One-month experiment results of April 2006 reveal that the data assimilation can correct the much overestimated aerosol surface mass concentration, and has a strong positive effect on the aerosol optical depth(AOD) simulation, improving agreement with observations. Improvement is limited with the?ngstr€om Exponent(AE) simulation, except for much improved correlation coefficient and model skill scores over the Ansai site. Better agreement of the AOD spatial distribution with the independent observations of Terra(Deep Blue) and Multi-angle Imaging Spectroradiometer(MISR) AODs is obtained by assimilating the Moderate Resolution Imaging Spectroradiometer(MODIS) AOD product, especially for regions with AODs lower than 0.30. This study confirms the usefulness of the remote sensing observations for the improvement of global aerosol modeling.展开更多
Nano-metric magnesium silicate and zinc silicate with particle size of about 50-70nm were prepared in water by the method of chemical deposition. The antiwear and friction reducing abilities of the nano-silicates, as ...Nano-metric magnesium silicate and zinc silicate with particle size of about 50-70nm were prepared in water by the method of chemical deposition. The antiwear and friction reducing abilities of the nano-silicates, as well as their composites with oleic acid tri-ethanolamine (OATEA), were evaluated on a four-ball friction tester. The topographies and tribochemical features of the worn surfaces were analyzed by scanning electron microscope (SEM) and X-ray photoelectron spectroscope (XPS). Results show that nano-silicates alone provide poor antiwear and friction reducing abilities in water, but exhibits excellent synergism with OATEA in reducing friction and wear. The synergism in reducing friction and wear between nano- silicates and OATEA does exist almost regardless of particte sizes and species, and may be attributed, on one hand, to the formation of an adsorption film of OATEA, and, on the other hand, to the formation oftribochemical species of silicon dioxide and iron oxides on the friction surfaces. Tribo-reactions and tribo-adsorptions of nano-silicates and OATEA would produce hereby an effective composite boundary lubrication film, which could efficiently enhance the anti-wear and friction-reducing abilities of water.展开更多
The α_ 2u-globulin,a soluble protein identified in the urine and preputial gland of adult male rat is reported to be pheromone carrier.The pup preputial gland plays a significant role in chemical communication for mo...The α_ 2u-globulin,a soluble protein identified in the urine and preputial gland of adult male rat is reported to be pheromone carrier.The pup preputial gland plays a significant role in chemical communication for mother-young interaction;however,the presence of a pheromone-carrying protein in the pup preputial gland has not been confirmed.Therefore,the present study was carried out to identify the α_ 2u-globulin in the pup preputial gland by Matrix Assisted Laser Desorption Ionization Time of Flight mass spectrometry(MALDI-TOF).The preputial glands of prepubertal rats were subjected to one-dimensional SDS-PAGE.In-gel trypsin digestion of a 18 kDa band was carried out and analyzed by MALDI-TOF.The results of a MASCOT search showed the presence of α_ 2u-globulin in the 18 kDa band.In contrast to the report of the synthesis of this protein only in adult rats,the identification of this protein in pup preputial gland is significant.The results suggest that synthesis of α_ 2u-globulin in the rat preputial gland starts in the prepubertal stage itself.In prepubertal rats,the preputial gland is a source of pheromone for performing anogenital licking behaviour by the mother rat.Since α_ 2u-globulin belongs to the lipocalin(ligand carrier)family,it might carry the volatile for processing pheromonal communication in mother-pup bonding in rat.展开更多
In order to determine and assess the concentrations of trace elements in coral reefs sediments from Red Sea of Yemen, sediment samples were collected, treated and analyzed for cadmium, chromium, cobalt, copper, mangan...In order to determine and assess the concentrations of trace elements in coral reefs sediments from Red Sea of Yemen, sediment samples were collected, treated and analyzed for cadmium, chromium, cobalt, copper, manganese, nickel, lead, iron, zinc and vanadium by the atomic absorption spectrometric analysis. The result is that cadmium, cobalt and lead concentrations were high and other elements are low or the same as natural background. It is concluded that the high cadmium, cobalt and lead levels in coral reefs sediments will have negative effects on marine life of the sites, so further researches are needed to characterize the sources fate, biogeochemical processes and impacts of these trace elements on coral reefs and marine of the region.展开更多
A new MeTAMP (thiazolylazo dye ligand 2-[2-(5-methyl thiazolyl)azo]-4-methoxy phenol) was prepared by coupling reaction between 5-methyl thiazolylazonium chloride with 4-methoxy phenol in alkaline alcoholic soluti...A new MeTAMP (thiazolylazo dye ligand 2-[2-(5-methyl thiazolyl)azo]-4-methoxy phenol) was prepared by coupling reaction between 5-methyl thiazolylazonium chloride with 4-methoxy phenol in alkaline alcoholic solution. The structure of azo dye ligand has been characterized by available technique such as 1H-NMR, mass spectrum, FT-IR, UV-vis and elemental analysis. Eight new chelate complexes of Cr(III), Mn(II), Fe(II), Fe(III), Co(III), Ni(II), Cu(II) and Zn(II) ions were prepared and identified by elemental analysis, atomic absorption, magnetic susceptibility, molar conductance measurements, FT-IR and electronic spectra. The spectral and analytical data show that the ligand a tridentate and coordinating with metal ions through the phenolate O, azo N atom which is the farthest of thiazole molecule and with thiazole N atom. The molar ratio (M:L) was also studied which was found 1:1 for Zn(II) and 1:2 for the rest metal ions. Conductivity measurements for prepared complexes showed 1:1 electrolyte for Cr(III), Fe(IlI), and Co(llI) complexes and non-electrolyte for rest complexes. Stability constants of complexes were calculated by spectrophotometry. Octahedral configuration suggested for Cr(III), Mn(II), Fe(II), Fe(III), Co(III), Ni(II) and Cu(II) but tetrahedral for Zn(IlI) complex. The solid complexes are found to have the general formula IML2]Cl H2O where M = Cr(III), Fe(III) and Co(IIl) and [ML2] H2O where M = Mn(II), Fe(II), Ni(II) and Cu(II) while [MLCI].H20 for Zn(II)-complex. The biological activity of ligand and its complexes against five types of bacteria, Strepto coccus and Staphylococcus aureus as example of gram positive, Pseudomonas, Proteus and Esherichia coli as example of gram negative bacteria by agar plate different technique was studied. The activity was also assayed on molecular level by using PCR in an attempt to monitor DNA banding pattern.展开更多
With the implementation of the GEOTRACES program, the biogeochemical cycle and distribution of tellurium (Te) in marine environments are becoming increasing environmental concerns. In this study, the concentration o...With the implementation of the GEOTRACES program, the biogeochemical cycle and distribution of tellurium (Te) in marine environments are becoming increasing environmental concerns. In this study, the concentration of dissolved Te in the Changjiang (Yangtze) River estuary and nearby waters was determined in May 2009 by hydride-generation atomic fluorescence spectrometry to elucidate the abundance, dominant species, distribution, and relationship with environmental factors. Results show that: (1) dissolved Te was low owing to its low abundance in the Earth's crust, high insolubility in water, and strong affinity to particulate matter; (2) Te(IV) and Te(VI) predominated in surface water. Te(VI) was the dominant species in bottom water, and Te(IV) was the minor species; (3) Horizontally, resulting from low phytoplankton metabolism and the weak reduction from Te(VI) to Te(IV) in the shore, Te(IV) was concentrated in the central zone instead of the coastal region. However, Te(VI) was abundant near the mouth of the Changjiang River where the Changjiang water is diluted and in the area to the south where the Taiwan Warm Current invaded. In the adsorption-desorption process, Te(IV) was negatively related to suspended paniculate matter (SPM), indicating that it was adsorbed by particulate matter. While for Te(VI), the positive correlation with SPM suggested that it was desorbed from the solid phase. In the estuary, dissolved Te had a negative correlation to salinity. However, it deviated from the dilution line in high-salinity regions due to the invasion of the Taiwan Warm Current and the mineralization of organic matter. The relationship between Te(IV) and SPM nutrients indicated that it was more bioavailable and more related to phosphorus than to nitrogen. Progress in the field is slow and more research is needed to quantify the input of Te to the estuary and evaluate the biochemical role of organisms.展开更多
We have investigated the pressure effect on the eletrorotation (ER) spectrum of living cell suspensions byconsidering the particle shape effect. In particular, we consider coated oblate spheroidal particles and presen...We have investigated the pressure effect on the eletrorotation (ER) spectrum of living cell suspensions byconsidering the particle shape effect. In particular, we consider coated oblate spheroidal particles and present a theoreticalstudy of ER based on the spectral representation theory. Analytic expressions for the characteristic frequency as wellas the dispersion strength can be obtained, thus simplifying the fitting of experimental data on oblate spheroidal cellsthat abound in the literature. From the theoretical analysis, we find that the cellshape, coating as well as materialparameters can change the ER spectrum. We demonstrate a good agreement between our theoretical predictions andexperimental data on human erthrocytes suspensions.展开更多
The functional materials based on natural zeolite (clinoptilolite), TiO2-zeolite and Ag-TiO2-zeolite have been successfully synthesized by solid-state reaction in fast-hydrothermal conditions. The obtained functiona...The functional materials based on natural zeolite (clinoptilolite), TiO2-zeolite and Ag-TiO2-zeolite have been successfully synthesized by solid-state reaction in fast-hydrothermal conditions. The obtained functional materials were investigated by X-ray diffraction (XRD), FT-1R (Fourier transform infrared) spectroscopy, DRUV-VIS (diffuse reflectance ultraviolet-visible) spectroscopy, BET (Brunauer-Emmett-Teller) and SEM/EDX (scanning electron microscope/energy dispersive X-ray spectrometer) analyses. The XRD results indicated that the clinoptilolite structure has a good thermal stabilization after the fast-hydrothermal treatment. Also, the high specific surface area about 92.55 m^2.g^-1 was noticed for Ag-TiO2-zeolite functional material. The presence of dopants was evidenced from EDX spectra. The enhanced bactericidal activity of Ag-TiO2-zeolite catalyst is proved through damaging of Enterococcusfaecalis colonies under visible irradiation, at different material doses and irradiation times.展开更多
Anisotropic metallic Nanoparticles (NPs) have unique optical properties, such as Surface Enhanced Raman Scattering (SERS) spearoscopy. In this paper, star-shaped and sphere gold NPs were prepared by seed-mediated ...Anisotropic metallic Nanoparticles (NPs) have unique optical properties, such as Surface Enhanced Raman Scattering (SERS) spearoscopy. In this paper, star-shaped and sphere gold NPs were prepared by seed-mediated growth and Frence methods respectively. The reaction process arid the effect of reagent in seed-mediated growth of gold naaostar particles were systematically described. After fabricaring NPs the authors test their Raman enhancement using Ch-ystal Violet (CV) moleolles apart. The experimental results indicated that star-shaped Au NPs had strtmger Raman enhancement spectrum than that of sphere Au NPs.展开更多
The aim of this work was to verify the potential of infrared (IR) spectroscopy in near and mid regions to detect the beginning of the malolactic fermentation (MLF) occurring in a model-wine and the further cells a...The aim of this work was to verify the potential of infrared (IR) spectroscopy in near and mid regions to detect the beginning of the malolactic fermentation (MLF) occurring in a model-wine and the further cells autolysis. MLF in wine is a secondary biotransformation due to lactic acid bacteria that usually occurs spontaneou,;ly or after starter inoculation at the end of alcoholic fermentation. Nowadays, it is desirable to supply winemakers with a new rapid and non-destructive approach to monitor MLF progress and 1R spectroscopy technology appears to be suitable for this purpose. The transformation of L-malic acid into L-lactic acid was carried out by inoculating a synthetic wine with an Oenococcus oeni culture and it was monitored through microbiological and chemical methods. At the same time, Fourier transform near infrared (FT-NIR) spectral data, in diffusive transflection mode using an optic probe, and FT-IR spectra, using an germanium crystal attenuated total reflectance (ATR) cell, were collected. Principal component analysis of the spectra was able to identify absorption bands related to the key molecular modifications that took place during the L-malic acid transformation. Thus, the samples were discriminated according to the fermentation phase. Although this study is a preliminary approach, results confirm that near infrared (NIR) and mid infrared (MIR) spectroscopy could be successfully applied to detect the start of MLF and the autolysis of the lactic acid bacteria (LAB) cells.展开更多
The ESA Sentinel-2 mission developed by European Aeronautic Defense and Space Compagny (EADS) Astrium will be devoted to Earth high resolution spectral imagery for the purpose of a global environmental monitoring. A...The ESA Sentinel-2 mission developed by European Aeronautic Defense and Space Compagny (EADS) Astrium will be devoted to Earth high resolution spectral imagery for the purpose of a global environmental monitoring. As a subcontractor of EADS Astrium, AMOS was responsible for the manufacturing of the instrument telescope mirrors and for the validation of the telescope alignment procedure. This paper details the mirror manufacturing sequences from mirror CVD-SiC cladding to surface figuring and coating, outlining the metrology steps and their corresponding accuracy budget. The telescope alignment process is described in connection with the tooling and techniques that helped achieve the required optical performance of less than 90 nm RMS wavefront error within the telescope field of view.Pierre Gloesenet展开更多
基金supported by the Specialized Research Fund for the Doctorial Progress of the Higher Education of China under Grant No.20040358019the National Natural Science Foundation of China under Grant No.10775097
文摘We re-explain the Weyl quantization scheme by virtue of the technique of integration within Weyl orderedproduct of operators,i.e.,the Weyl correspondence rule can be reconstructed by classical functions' Fourier transfor-mation followed by an inverse Fourier transformation within Weyl ordering of operators.As an application of thisreconstruction,we derive the quantum operator coresponding to the angular spectrum amplitude of a spherical wave.
基金the National Natural Science Foundation of China(51872173 and 51772176)Taishan Scholarship of Young Scholars(tsqn201812068)+2 种基金Natural Science Foundation of Shandong Province(ZR2017JL020)Taishan Scholarship of Climbing Plan(tspd20161006)Key Research and Development Program of Shandong Province(2018GGX102028)~~
文摘Herein, novel plasmonic Bi metal in situ deposited in reduced Ti O2 microspheres(Bi@R-Ti O2) are fabricated via a bimetallic MOF-derived synthesized strategy by adjusting the synthesizing temperature. Different characterization techniques, including XRD, SEM, TEM, XPS, DRS, PL, EIS, and photocurrent generation, are performed to investigate the structural and optical properties of the as-prepared samples. The results indicate that the Bi particles are generated inside and outside of reduced Ti O2 microspheres via the reduction of Ti4+ and Bi3+ by ethylene glycol. When the annealing temperature is controlled at 300 o C, the corresponding Bi@R-Ti O2-300 sample with an appropriate amount of Bi nanoparticles exhibits the highest full solar spectrum photocatalytic oxygen evolution activity(4728.709 μmol h–1 g–1), which is 5.9 and 9.5 times higher than that of pure Ti O2 and Bi-Ti bimetal organic frameworks(Bi-Ti-MOFs). Several reasons are suggested for the above results:(1) Bi metal behaves as an "electron acceptor" to accelerate the charge carrier transfer from Ti O2 to Bi;(2) The surface plasmon resonance effect of loaded metallic Bi particles can enhance the visible and NIR light absorption capacity;(3) The generation of Ti3+ further narrows the band gap of TiO2.
基金Under the auspices of National Key Research and Development Program(No.2016YFC0500203)National Natural Science Foundation of China(No.41571427)
文摘Water vapor in the earth′s upper atmosphere plays a crucial role in the radiative balance, hydrological process, and climate change. Based on the latest moderate-resolution imaging spectroradiometer(MODIS) data, this study probes the spatio-temporal variations of global water vapor content in the past decade. It is found that overall the global water vapor content declined from 2003 to 2012(slope b = –0.0149, R = 0.893, P = 0.0005). The decreasing trend over the ocean surface(b = –0.0170, R = 0.908, P = 0.0003) is more explicit than that over terrestrial surface(b = –0.0100, R = 0.782, P = 0.0070), more significant over the Northern Hemisphere(b = –0.0175, R = 0.923, P = 0.0001) than that over the Southern Hemisphere(b = –0.0123, R = 0.826, P = 0.0030). In addition, the analytical results indicate that water vapor content are decreasing obviously between latitude of 36°N and 36°S(b = 0.0224, R = 0.892, P = 0.0005), especially between latitude of 0°N and 36°N(b = 0.0263, R = 0.931, P = 0.0001), while the water vapor concentrations are increasing slightly in the Arctic regions(b = 0.0028, R = 0.612, P = 0.0590). The decreasing and spatial variation of water vapor content regulates the effects of carbon dioxide which is the main reason of the trend in global surface temperatures becoming nearly flat since the late 1990 s. The spatio-temporal variations of water vapor content also affect the growth and spatial distribution of global vegetation which also regulates the global surface temperature change, and the climate change is mainly caused by the earth's orbit position in the solar and galaxy system. A big data model based on gravitational-magmatic change with the solar or the galactic system is proposed to be built for analyzing how the earth's orbit position in the solar and galaxy system affects spatio-temporal variations of global water vapor content, vegetation and temperature at large spatio-temporal scale. This comprehensive examination of water vapor changes promises a holistic understanding of the global climate change and potential underlying mechanisms.
基金Under the auspices of National Nature Science Foundation of China(No.40901231,41101517)
文摘In this paper,a thin cloud removal method was put forward based on the linear relationships between the thin cloud reflectance in the channels from 0.4 μm to 1.0 μm and 1.38 μm.Channels of 0.66 μm,0.86 μm and 1.38 μm were chosen to extract the water body information under the thin cloud.Two study cases were selected to validate the thin cloud removal method.One case was applied with the Earth Observation System Moderate Resolution Imaging Spectroradiometer(EOS/MODIS) data,and the other with the Medium Resolution Spectral Imager(MERSI) and Visible and Infrared Radiometer(VIRR) data from Fengyun-3A(FY-3A).The test results showed that thin cloud removal method did not change the reflectivity of the ground surface under the clear sky.To the area contaminated by the thin cloud,the reflectance decreased to be closer to the reference reflectance under the clear sky after the thin cloud removal.The spatial distribution of the water body area could not be extracted before the thin cloud removal,while water information could be easily identified by using proper near infrared channel threshold after removing the thin cloud.The thin cloud removal method could improve the image quality and water body extraction precision effectively.
基金Supported by the National Natural Science Foundation of China (21004055) and the Doctoral Discipline Foundation of Education Ministry (20104101110005).
文摘The suspension polymerization with two organic phases was adopted to prepare spherical hyper- crosslinked resin by self-polycondensation of 4,4'-bis-(chloromethyl)- 1, 1'-biphenyl (CMB). The chemical structure,morphology and pore characteristics of the novel spherical resin were characterized with Fourier transform infrared spectroscopy (FTIR), micrograph and Brunauer-Emmett-Teller (BET). It is found that the suspension system and stirring speed impose a great influence upon the regularity and size distribution of hypercrosslinked beads. To prepare CMB resin beads with diameter of about 300 μm, the optimal condition is as follows: stirring speed 300 r·min^-1, and the volume ratio of the two organic phases (nitrobenzene/dimethyl silicon oil) 1 : 5. After the self-polycondensation and sqccedent post-crosslinking of CMB monomer, the spherical adsorbent presents high spec^al surface area (1190 m^2· g^-1) and abundant pore^volume (0.714 cm^3· g^-1), and could be potentially applied qn the adsorption of various organic molecules and synthesis of porous ion exchanger.
基金financially supported by the National Basic Research Program of China(2011CB403405 and 2010CB955608)the Public Meteorology Special Foundation of MOST(GYHY200906020)
文摘Black carbon (BC) aerosols can strongly absorb solar radiation in very broad spectral wavebands, from the visible to the infrared. As a potential factor contributing to global warming, BC aerosols not only directly change the radiation balance of the earth-atmosphere system, but also indirectly affect global or regional climate by acting as cloud conden- sation nuclei or ice nuclei to alter cloud mierophysical properties. Here, recent progresses in the studies of radiative forcing due to BC and its climate effects are reviewed. The uncertainties in current researches are discussed and some suggestions are provided for future investigations.
基金Supported by the National Natural Science Foundation of China(51090384)
文摘Antibacterial activity of boron-doped TiO2(B/TiO2) nano-materials under visible light irradiation and in the dark was investigated. A simple sol-gel method was used to synthesize TiO2 nano-materials. X-ray diffraction pattern of B/TiO2 nano-materials represents the diffraction peaks relating to the crystal planes of TiO2(anatase and rutile). X-ray photoelectron spectroscopy result shows that part of boron ions incorporates into TiO2 lattice to form a possible chemical environment like Ti O B and the rest exist in the form of B2O3. The study on antibacterial effect of B/TiO2 nano-materials on fungal Candida albicans(ATCC10231), Gram-negative Escherichia coli(ATCC25922) and Gram-positive Staphylococcus aureus(ATCC6538) shows that the antibacterial action is more significant on Candida albicans than on Escherichia coli and Staphylococcus aureus. Under visible light irradiation, the antibacterial activity is superior to that in the dark.
文摘An efficient method to track the carrier frequency which is recommended to use in low earth orbit(LEO) direct-sequence spread-spectrum(DS/SS) communication system is given. The carrier frequency drifts quicker in LEO DS/SS communication system, its tracking problem becomes much more important especially in digital receiver with the limits of physical shape and power. Under the condition of coarse carrier frequency synchronization, a digital tracking method based on least square method(LSM) is proved to be a quick, simple and efficient method. Numerical results and charts are given.
基金supported by the funds from the National Natural Science Funds of China (41475031, 41130104)the Public Meteorology Special Foundation of MOST (GYHY201406023)+1 种基金the special fund of State Key Joint Laboratory of Environment Simulation and Pollution Control(15K02ESPCP)the JAXA/Earth CARE, the MEXT/VL for Climate System Diagnostics, the MOE/Global Environment Research Fund S-12 (14426634)and A-1101, the NIES/GOSAT, theS/ NIECGER, and the MEXT/RECCA/SALSA
文摘A Local Ensemble Transform Kalman Filter assimilation system has been implemented into an aerosol-coupled global nonhydrostatic model to simulate the aerosol mass concentration and aerosol optical properties of 3 desert sites(Ansai, Fukang, Shapotou) in northwestern China. One-month experiment results of April 2006 reveal that the data assimilation can correct the much overestimated aerosol surface mass concentration, and has a strong positive effect on the aerosol optical depth(AOD) simulation, improving agreement with observations. Improvement is limited with the?ngstr€om Exponent(AE) simulation, except for much improved correlation coefficient and model skill scores over the Ansai site. Better agreement of the AOD spatial distribution with the independent observations of Terra(Deep Blue) and Multi-angle Imaging Spectroradiometer(MISR) AODs is obtained by assimilating the Moderate Resolution Imaging Spectroradiometer(MODIS) AOD product, especially for regions with AODs lower than 0.30. This study confirms the usefulness of the remote sensing observations for the improvement of global aerosol modeling.
基金supported by the National Natural Science Foundation of China (No. 50275147)the Program for New Century Excellent Talents in Chinese University (No. NCET-04-1002)
文摘Nano-metric magnesium silicate and zinc silicate with particle size of about 50-70nm were prepared in water by the method of chemical deposition. The antiwear and friction reducing abilities of the nano-silicates, as well as their composites with oleic acid tri-ethanolamine (OATEA), were evaluated on a four-ball friction tester. The topographies and tribochemical features of the worn surfaces were analyzed by scanning electron microscope (SEM) and X-ray photoelectron spectroscope (XPS). Results show that nano-silicates alone provide poor antiwear and friction reducing abilities in water, but exhibits excellent synergism with OATEA in reducing friction and wear. The synergism in reducing friction and wear between nano- silicates and OATEA does exist almost regardless of particte sizes and species, and may be attributed, on one hand, to the formation of an adsorption film of OATEA, and, on the other hand, to the formation oftribochemical species of silicon dioxide and iron oxides on the friction surfaces. Tribo-reactions and tribo-adsorptions of nano-silicates and OATEA would produce hereby an effective composite boundary lubrication film, which could efficiently enhance the anti-wear and friction-reducing abilities of water.
基金supported by grants from the University Grants Commission and partially from UGC-SAP and DST-FIST,Government of India
文摘The α_ 2u-globulin,a soluble protein identified in the urine and preputial gland of adult male rat is reported to be pheromone carrier.The pup preputial gland plays a significant role in chemical communication for mother-young interaction;however,the presence of a pheromone-carrying protein in the pup preputial gland has not been confirmed.Therefore,the present study was carried out to identify the α_ 2u-globulin in the pup preputial gland by Matrix Assisted Laser Desorption Ionization Time of Flight mass spectrometry(MALDI-TOF).The preputial glands of prepubertal rats were subjected to one-dimensional SDS-PAGE.In-gel trypsin digestion of a 18 kDa band was carried out and analyzed by MALDI-TOF.The results of a MASCOT search showed the presence of α_ 2u-globulin in the 18 kDa band.In contrast to the report of the synthesis of this protein only in adult rats,the identification of this protein in pup preputial gland is significant.The results suggest that synthesis of α_ 2u-globulin in the rat preputial gland starts in the prepubertal stage itself.In prepubertal rats,the preputial gland is a source of pheromone for performing anogenital licking behaviour by the mother rat.Since α_ 2u-globulin belongs to the lipocalin(ligand carrier)family,it might carry the volatile for processing pheromonal communication in mother-pup bonding in rat.
文摘In order to determine and assess the concentrations of trace elements in coral reefs sediments from Red Sea of Yemen, sediment samples were collected, treated and analyzed for cadmium, chromium, cobalt, copper, manganese, nickel, lead, iron, zinc and vanadium by the atomic absorption spectrometric analysis. The result is that cadmium, cobalt and lead concentrations were high and other elements are low or the same as natural background. It is concluded that the high cadmium, cobalt and lead levels in coral reefs sediments will have negative effects on marine life of the sites, so further researches are needed to characterize the sources fate, biogeochemical processes and impacts of these trace elements on coral reefs and marine of the region.
文摘A new MeTAMP (thiazolylazo dye ligand 2-[2-(5-methyl thiazolyl)azo]-4-methoxy phenol) was prepared by coupling reaction between 5-methyl thiazolylazonium chloride with 4-methoxy phenol in alkaline alcoholic solution. The structure of azo dye ligand has been characterized by available technique such as 1H-NMR, mass spectrum, FT-IR, UV-vis and elemental analysis. Eight new chelate complexes of Cr(III), Mn(II), Fe(II), Fe(III), Co(III), Ni(II), Cu(II) and Zn(II) ions were prepared and identified by elemental analysis, atomic absorption, magnetic susceptibility, molar conductance measurements, FT-IR and electronic spectra. The spectral and analytical data show that the ligand a tridentate and coordinating with metal ions through the phenolate O, azo N atom which is the farthest of thiazole molecule and with thiazole N atom. The molar ratio (M:L) was also studied which was found 1:1 for Zn(II) and 1:2 for the rest metal ions. Conductivity measurements for prepared complexes showed 1:1 electrolyte for Cr(III), Fe(IlI), and Co(llI) complexes and non-electrolyte for rest complexes. Stability constants of complexes were calculated by spectrophotometry. Octahedral configuration suggested for Cr(III), Mn(II), Fe(II), Fe(III), Co(III), Ni(II) and Cu(II) but tetrahedral for Zn(IlI) complex. The solid complexes are found to have the general formula IML2]Cl H2O where M = Cr(III), Fe(III) and Co(IIl) and [ML2] H2O where M = Mn(II), Fe(II), Ni(II) and Cu(II) while [MLCI].H20 for Zn(II)-complex. The biological activity of ligand and its complexes against five types of bacteria, Strepto coccus and Staphylococcus aureus as example of gram positive, Pseudomonas, Proteus and Esherichia coli as example of gram negative bacteria by agar plate different technique was studied. The activity was also assayed on molecular level by using PCR in an attempt to monitor DNA banding pattern.
基金Supported by the National Basic Research Program of China(973 Program)(No.2011CB403602)the National Natural Science Foundation of China(No.41121064)
文摘With the implementation of the GEOTRACES program, the biogeochemical cycle and distribution of tellurium (Te) in marine environments are becoming increasing environmental concerns. In this study, the concentration of dissolved Te in the Changjiang (Yangtze) River estuary and nearby waters was determined in May 2009 by hydride-generation atomic fluorescence spectrometry to elucidate the abundance, dominant species, distribution, and relationship with environmental factors. Results show that: (1) dissolved Te was low owing to its low abundance in the Earth's crust, high insolubility in water, and strong affinity to particulate matter; (2) Te(IV) and Te(VI) predominated in surface water. Te(VI) was the dominant species in bottom water, and Te(IV) was the minor species; (3) Horizontally, resulting from low phytoplankton metabolism and the weak reduction from Te(VI) to Te(IV) in the shore, Te(IV) was concentrated in the central zone instead of the coastal region. However, Te(VI) was abundant near the mouth of the Changjiang River where the Changjiang water is diluted and in the area to the south where the Taiwan Warm Current invaded. In the adsorption-desorption process, Te(IV) was negatively related to suspended paniculate matter (SPM), indicating that it was adsorbed by particulate matter. While for Te(VI), the positive correlation with SPM suggested that it was desorbed from the solid phase. In the estuary, dissolved Te had a negative correlation to salinity. However, it deviated from the dilution line in high-salinity regions due to the invasion of the Taiwan Warm Current and the mineralization of organic matter. The relationship between Te(IV) and SPM nutrients indicated that it was more bioavailable and more related to phosphorus than to nitrogen. Progress in the field is slow and more research is needed to quantify the input of Te to the estuary and evaluate the biochemical role of organisms.
文摘We have investigated the pressure effect on the eletrorotation (ER) spectrum of living cell suspensions byconsidering the particle shape effect. In particular, we consider coated oblate spheroidal particles and present a theoreticalstudy of ER based on the spectral representation theory. Analytic expressions for the characteristic frequency as wellas the dispersion strength can be obtained, thus simplifying the fitting of experimental data on oblate spheroidal cellsthat abound in the literature. From the theoretical analysis, we find that the cellshape, coating as well as materialparameters can change the ER spectrum. We demonstrate a good agreement between our theoretical predictions andexperimental data on human erthrocytes suspensions.
基金Supported by the Sectoral Operational Programme Human Resources Development(SOP HRD)Financed from the European Social Fundthe Romanian Government under the Contract Number POSDRU/89/1.5/S/63700
文摘The functional materials based on natural zeolite (clinoptilolite), TiO2-zeolite and Ag-TiO2-zeolite have been successfully synthesized by solid-state reaction in fast-hydrothermal conditions. The obtained functional materials were investigated by X-ray diffraction (XRD), FT-1R (Fourier transform infrared) spectroscopy, DRUV-VIS (diffuse reflectance ultraviolet-visible) spectroscopy, BET (Brunauer-Emmett-Teller) and SEM/EDX (scanning electron microscope/energy dispersive X-ray spectrometer) analyses. The XRD results indicated that the clinoptilolite structure has a good thermal stabilization after the fast-hydrothermal treatment. Also, the high specific surface area about 92.55 m^2.g^-1 was noticed for Ag-TiO2-zeolite functional material. The presence of dopants was evidenced from EDX spectra. The enhanced bactericidal activity of Ag-TiO2-zeolite catalyst is proved through damaging of Enterococcusfaecalis colonies under visible irradiation, at different material doses and irradiation times.
文摘Anisotropic metallic Nanoparticles (NPs) have unique optical properties, such as Surface Enhanced Raman Scattering (SERS) spearoscopy. In this paper, star-shaped and sphere gold NPs were prepared by seed-mediated growth and Frence methods respectively. The reaction process arid the effect of reagent in seed-mediated growth of gold naaostar particles were systematically described. After fabricaring NPs the authors test their Raman enhancement using Ch-ystal Violet (CV) moleolles apart. The experimental results indicated that star-shaped Au NPs had strtmger Raman enhancement spectrum than that of sphere Au NPs.
文摘The aim of this work was to verify the potential of infrared (IR) spectroscopy in near and mid regions to detect the beginning of the malolactic fermentation (MLF) occurring in a model-wine and the further cells autolysis. MLF in wine is a secondary biotransformation due to lactic acid bacteria that usually occurs spontaneou,;ly or after starter inoculation at the end of alcoholic fermentation. Nowadays, it is desirable to supply winemakers with a new rapid and non-destructive approach to monitor MLF progress and 1R spectroscopy technology appears to be suitable for this purpose. The transformation of L-malic acid into L-lactic acid was carried out by inoculating a synthetic wine with an Oenococcus oeni culture and it was monitored through microbiological and chemical methods. At the same time, Fourier transform near infrared (FT-NIR) spectral data, in diffusive transflection mode using an optic probe, and FT-IR spectra, using an germanium crystal attenuated total reflectance (ATR) cell, were collected. Principal component analysis of the spectra was able to identify absorption bands related to the key molecular modifications that took place during the L-malic acid transformation. Thus, the samples were discriminated according to the fermentation phase. Although this study is a preliminary approach, results confirm that near infrared (NIR) and mid infrared (MIR) spectroscopy could be successfully applied to detect the start of MLF and the autolysis of the lactic acid bacteria (LAB) cells.
文摘The ESA Sentinel-2 mission developed by European Aeronautic Defense and Space Compagny (EADS) Astrium will be devoted to Earth high resolution spectral imagery for the purpose of a global environmental monitoring. As a subcontractor of EADS Astrium, AMOS was responsible for the manufacturing of the instrument telescope mirrors and for the validation of the telescope alignment procedure. This paper details the mirror manufacturing sequences from mirror CVD-SiC cladding to surface figuring and coating, outlining the metrology steps and their corresponding accuracy budget. The telescope alignment process is described in connection with the tooling and techniques that helped achieve the required optical performance of less than 90 nm RMS wavefront error within the telescope field of view.Pierre Gloesenet