Essential oils(EOs)derived from medicinal plants are gaining recognition as sustainable alternatives to synthetic fungicides in the management of plant pathogens.This study investigates the chemical composition,chroma...Essential oils(EOs)derived from medicinal plants are gaining recognition as sustainable alternatives to synthetic fungicides in the management of plant pathogens.This study investigates the chemical composition,chromatographic profile,and antifungal of Mentha rotundifolia essential oil against Fusarium oxysporum f.sp.albedinis(Foa),the pathogen responsible for Bayoud disease in date palm.The oil was extracted through hydrodistillation and characterized using thin-layer chromatography(TLC)and gas chromatography–mass spectrometry(GC-MS),revealing multiple fractions corresponding to terpenoid constituents and 23 chemical constituents,predominantly oxygenated monoterpenes(68.51%),with piperitenone oxide as the major component(62.53%).The antifungal efficacy was evaluated against ten(10)isolates of F.o.a across seven(07)concentrations different concentrations.(0;0.25;0.5;0.75;1;1.25;1.5μL/mL).The results obtained show a progressive decrease in the diameters of the colonies of F.o.a isolates by increasing the doses of EOMR.The percentage of inhibition varies from 7.82 to 83.41%;However,the dose of 1.75μL/mL showed 100%inhibition for all F.o.a isolates tested.These outcomes demonstrate the potential of M.rotundifolia essential oil as a natural,environmentally friendly antifungal agent,supporting its application in sustainable management strategies for Bayoud disease in date palm.展开更多
Study of 1986 and 1987 heavy metal distribution in surface water of the Kuroshio area in the East China Sea showed regional and slight seasonal variations in distribution and concentration . Heavy metal levels in Taiw...Study of 1986 and 1987 heavy metal distribution in surface water of the Kuroshio area in the East China Sea showed regional and slight seasonal variations in distribution and concentration . Heavy metal levels in Taiwan Strait, the sea area north of Taiwan and the continental shelf are higher than those in the main axis of the Kuroshio . Dissolved Cu in summer and winter decreases with the increase of salinity , but dissolved Cd has no obvious change with salinity .展开更多
Color mothball is a daily necessity in Southeast Asia. Mothball contained nearly 100% naphthalene or 100% p-dichlorobenzene. It was used to resist insects, mothproof and mildew with a special odor. In other words, the...Color mothball is a daily necessity in Southeast Asia. Mothball contained nearly 100% naphthalene or 100% p-dichlorobenzene. It was used to resist insects, mothproof and mildew with a special odor. In other words, the odor was thought unpleasant enough to drive animals away in repellent products. This research analyzed color mothball which was manufactured by C and N companies. The mothball was dyed with eight dyes and three essences of fragrance, respectively. The experiment of color fastness with UV-light test is to determine how much the color will fade, when it exposed to a known ultraviolet light source. In the last analysis, the experimental data from the spectrum of GC/MS described all kinds of structure on color mothball after 80 hours phototherapy treatment as shown in the content. This research reveals that color mothball can have better appearance and greater performance, to meet the requirements for customs and various applications.展开更多
An alkaline precipitation method was introduced to produce hydrous cerium oxides.The prepared powder was characterized by Brunauer-Emmett-Teller（BET） nitrogen adsorption-desorption,X-ray diffraction（XRD）,Fourier t...An alkaline precipitation method was introduced to produce hydrous cerium oxides.The prepared powder was characterized by Brunauer-Emmett-Teller（BET） nitrogen adsorption-desorption,X-ray diffraction（XRD）,Fourier transform infrared（FTIR） spectrometry,and thermal gravimetry（TG） approaches.The adsorbent has a chemical formula of CeO2·nH2O（n 2） and a cubic fluorite-type structure after high temperature treatment.Adsorption capacity of different temperature treated hydrous cerium oxides does not directly correlate with BET specific surface area.Phosphate adsorption isotherms follow the Langmuir equation below the treatment temperature of 800°C.Phosphate adsorption causes no change on the structure of a hydrous cerium oxides,and no signs of CePO4 precipitates are found.The ion-exchanging structure of hydrous cerium oxide plays a fundamental role in phosphate adsorption.The structure is highly temperature resistant and forms adsorption sites which adsorb both water and some anions.Complete loss of adsorption ability cannot be achieved unless the treatment temperature is higher than 1200°C.Mechanism study shows that the adsorption of phosphates is mainly an anion-exchange process.展开更多
With outstanding analytical performance and portability, miniature mass spectrometer is one of the most powerful tools for in-situ analysis. The miniaturization of mass spectrometers has lasted for more than ten years...With outstanding analytical performance and portability, miniature mass spectrometer is one of the most powerful tools for in-situ analysis. The miniaturization of mass spectrometers has lasted for more than ten years, during which a number of miniature mass spectrometers employing different techniques have been developed. Small-in-size, working at relatively high pressure region and capable of performing tandem mass spectrometry, ion trap is the most widely used mass analyzer in miniature mass spectrometer systems. The recent development of miniature ion trap mass spectrometer systems in the last ten years was reviewed in this paper. These instruments adopt different atmospheric pressure interfaces （APIs）, which are membrane inlets （MIs）, discontinuous atmospheric pressure interface （DAPI） and continuous atmospheric pressure interface （CAPI）. This review emphasizes on the mini mass spectrometry （MS） system that can be handheld by one person, but not the field-able ones that are too large to be hand-portable.展开更多
A new composition of Portland cement clinker was studied, in which KH, SM and IM was 0.98,2.4 and 2.4 respectively as well as its meal added 1%CuO （in mass）. Fired at 1 200℃,1 350℃,1 400℃ and 1 450℃ for 30 min, ...A new composition of Portland cement clinker was studied, in which KH, SM and IM was 0.98,2.4 and 2.4 respectively as well as its meal added 1%CuO （in mass）. Fired at 1 200℃,1 350℃,1 400℃ and 1 450℃ for 30 min, the resultant mineral phases component and mineral morphology were analyzed. The performances of the cement which was made of clinker burned at 1 450℃ and fly ash were determined. By means of QXRD, XRD and optical microscopy, it is shown that the clinker burnt at 1 450℃ has the larger size crystals and distinct crystal interface, in which the C3S content is 73.37% and the mineral phases is dominantly C3S, following by minor C2S, C3A and tetracalcium aluminoferrite. The results reveal that a new type of high C3S content clinker can completely be made by traditional temperature-time schedule. The performances of the cement produced from this clinker with addtion of 50% fly ash and 5% gupsum were in agreement with the 32.5 strength grade of Portland fly-ash cement. The results also show that the clinker has a significant effect of saving energy and utilizing waste slag.展开更多
To investigate the influence of extractable organic matter （EOM） on pore evolution of lacustrine shales, Soxhlet extraction, using dichloromethane, was performed on a series of Chang 7 shale samples （Ordos Basin, C...To investigate the influence of extractable organic matter （EOM） on pore evolution of lacustrine shales, Soxhlet extraction, using dichloromethane, was performed on a series of Chang 7 shale samples （Ordos Basin, China） with vitrinite reflectance of 0.64% to 1.34%. Low-pressure gas adsorption experiments were conducted on the samples before and after extraction. The pore structure parameters were calculated from the gas adsorption data. The results show complex changes to the pore volumes and surface areas after extraction. The pore development of both the initial and extracted samples is strongly controlled by total organic carbon （TOC） content. Micropores developed mainly in organic matter （OM）, while mesopores and macropores predominantly developed in fractions other than OM. The influence of EOM on micropores is stronger than on mesopores and macropores. Organic solvents with a higher boiling point should be used to explore the effect of EOM on pore structure in the future.展开更多
Organic matter(OM)and minerals are major particle components of lacustrine shales.The influence of OM and minerals on pore space and structure in organic-rich oil-prone shales containing a large range of total organic...Organic matter(OM)and minerals are major particle components of lacustrine shales.The influence of OM and minerals on pore space and structure in organic-rich oil-prone shales containing a large range of total organic carbon(TOC)contents is poorly understood.In this study,we investigated the variation in pore space and structure of low mature lacustrine shales in the Songliao Basin(NE China),based on a study of the mineralogy,petrography,geochemistry,and geophysical properties of shales.Different pore types make markedly different contributions to the mineral surface area(MSA)and pore volume(PV)of the shales.There exists a negative correlation between MSA/PV and TOC in mesopores(r^(2)=0.75/0.65)and macropores(r^(2)=0.74/0.68),and a positive correlation in micropores(r^(2)=0.59/0.64),which are associated with the variation of mineral and TOC contents.A positive relationship between the throat/pore ratio and TOC(r^(2)=0.82)shows an increase in throat radius and decrease in pore radius with increasing TOC content.This relationship is supported by the reduction in mean pore diameter(MPD)for large pores and increase in MPD for small pores.These variations are related to the decreased pores by quartz plus feldspar(Q+F)content,increased throats by clay minerals,an d enhanced pore-fill by OM.We propose that the variation of OM and minerals is a key control on the pore space and structure of low mature organic-rich oil-prone shales.展开更多
Most of the structural alloys’applications are under static,dynamic,and cyclic forms of loading.Ti-5553 alloy in the beta phase field is being investigated to confirm the mechanism of deformation and phase transforma...Most of the structural alloys’applications are under static,dynamic,and cyclic forms of loading.Ti-5553 alloy in the beta phase field is being investigated to confirm the mechanism of deformation and phase transformation upon quasi-static and dynamic compression.The Ti-5553 alloy was heat-treated at 900℃ (almost 50℃ above beta transus temperature)for one hour of soaking time followed by air quenching to achieve a fullyβphase field.After that,Dynamic compression(DC)by Split Hopkinson Pressure Bar(SHPB)and Quasi-static compression(QSC)were performed at a strain rate of~10^3)/s and 10^(-3)/s,respectively.Recovered specimens were thoroughly examined by using different tools,such as an Optical microscope(OM),Scanning electron microscope(SEM),High-resolution transmission electron microscope(HRTEM),and Electron backscatter diffraction(EBSD)to get the reliable data for justification of logical conclusions.It is found that the dominating mode of deformation was dislocation slip along with twinning({332}<113>)to some extent in both of QSC and DC,but sliding&spalling of the grain boundary is observed more in the former.Stress-induced phase transformation,i.e.,βtoα"andβtoω,took place in the grains saturated with dislocation slips,where the former transformation occurred simultaneously with{332}<113>twinning,whileβtoωtransformation was completed when a set of two adjacent(110)_(β)planes covered±1/6th of the total separation distance between two(next to each other)(111)_(β)planes,by equal but opposite shear in(111)_(β)direction,and it caused 3%shrinkage of two closed packed(110)_(β)planes after transformation.展开更多
Water regulation of the Xiaolangdi Reservoir of the Yellow River was chosen as a case to investigate variations in concentrations and bioavailability of heavy metals caused by water conservancy projects in rivers. Wat...Water regulation of the Xiaolangdi Reservoir of the Yellow River was chosen as a case to investigate variations in concentrations and bioavailability of heavy metals caused by water conservancy projects in rivers. Water and suspended sediment（SPS） samples were collected at downstream sampling sites along the river during this period. Concentrations and speciation of Zn, Cr, Cu, Ni, and Pb in water and SPS samples were analyzed, and their bioaccumulation was studied with Daphnia magna. This study indicated that the exchangeable and carbonatebound fractions of heavy metals in SPS decreased along the studied stretch, and the dissolved heavy metal concentrations increased along the river with 1.6–15 folds. This is because sediment resuspension increased along the river during water regulation, giving rise to the increase of heavy metal release from SPS. The dissolved Zn, Cu, Ni, and Pb concentrations were significantly positively correlated with SPS concentrations, and their increase along the river was greater than Cr. The body burdens of heavy metals in D. magna exposed into samples collected from the reservoir outlet were 1.3–3.0 times lower than those from downstream stations, suggesting that the heavy metal bioavailability increased during water regulation.This should be considered in the reservoir operation.展开更多
A new paradigm for ship detection in polarimetric synthetic aperture radar(Pol-SAR)image is presented.We firstly utilize the scattering similarity parameters to investigate the differences of scattering mechanism betw...A new paradigm for ship detection in polarimetric synthetic aperture radar(Pol-SAR)image is presented.We firstly utilize the scattering similarity parameters to investigate the differences of scattering mechanism between ships and sea clutter.Based on these differences,we propose a novel ship detection metric,denoted as the scattering similarity based metric(SSM),to conduct ship detection task.The distribution model of SSM metric is investigated and modeled by kernel density estimation(KDE).Based on the statistical distribution,an adaptive constant false alarm rate(CFAR)detection scheme is implemented.We compare the proposed SSM with two classic polarimetric metrics,i.e.,the polarimetric cross-entropy(PCE)and the reflection symmetry metric(RSM).The experimental results conducted on C-band RADARSAT-2 Pol-SAR data demonstrate the feasibility and advantage of the proposed SSM metric both in sea clutter modeling and in ship detection.展开更多
To investigate pore characteristics and the factors controlling lacustrine shales,geochemical,mineralogical and petrophysical experiments were performed on 23 shale samples from the Qingshankou Formation of the Songli...To investigate pore characteristics and the factors controlling lacustrine shales,geochemical,mineralogical and petrophysical experiments were performed on 23 shale samples from the Qingshankou Formation of the Songliao Basin,China.A comparison of mercury injection capillary pressure(MICP)and low-temperature N2 adsorption pore-size distribution showed that MICP has a higher pore-size distribution(PSD)line in its overlapping pore diameter range,which may be elevated by the higher pressure of MICP.Therefore,in the overlapping range,low-temperature N2 adsorption data were preferred in pore characterization.Negative correlations were observed between pore volumes and TOC content,indicating organic matter pores are not well-developed in the studied samples.This may be related to their low grade of maturity and type I kerogens.There existed negative relationships between pore volumes and S1,which illustrated that liquid hydrocarbons occupied some pore space.Micropore volume had a better correlation with S1 than mesopore and macropore volumes,which suggests that liquid hydrocarbons preferentially occur in micropores.No obvious relationships between pore volumes and quartz or feldspar were observed,while pore volumes increased with the increasing clay mineral content.These relationships indicate that intraparticle pores in clay minerals represent the principal pore type.展开更多
[Objectives] The aim of this work was to compare the inhibitory effects of different water-soluble extracts of ginseng on hydroxyl radical. [Methods]The water-soluble effective parts of ginseng were extracted by ortho...[Objectives] The aim of this work was to compare the inhibitory effects of different water-soluble extracts of ginseng on hydroxyl radical. [Methods]The water-soluble effective parts of ginseng were extracted by orthogonal test,the hydroxyl radical scavenging rate of each extract was determined by salicylic acid method,and the extraction process of the optimum hydroxyl radical inhibitor was optimized using variance analysis and cluster analysis. [Results] A total of 16 samples were prepared. Among them,the sample No. 12 had the highest hydroxyl radical scavenging rate,and the inhibition rate reached 105. 08% at the concentration of 1 g/L. [Conclusions] Ginseng water extract contained hydroxyl radical scavenger,of which the optimum extraction process was as follows: p H of 8,solid to liquid ratio of 1∶ 10,extraction temperature of 4℃,extraction time of 12 h and extraction times of 3.展开更多
The adsorption capacities of new humic acids isolated from Yakouren forest （YHA） and Sahara （Tamenrasset： THA） soils （Algeria） and commercial humic acid （PFHA） on polyaniline emeraldine base （PEB） were stud...The adsorption capacities of new humic acids isolated from Yakouren forest （YHA） and Sahara （Tamenrasset： THA） soils （Algeria） and commercial humic acid （PFHA） on polyaniline emeraldine base （PEB） were studied at pH 6.6. Also the adsorption of heavy metals such as Cd 2＋ , Zn 2＋ and Ni 2＋ on humic acid-polyaniline systems （HA-PEB） was investigated at the same conditions. HA-PEB compounds were characterized by scanning electron microscopy （SEM）, infrared spectrometry and cavity microelectrode. In addition, batch adsorption and cavity microelectrode were used in the adsorption study of Cd 2＋ , Zn 2＋ and Ni 2＋ on HA-PEB. To develop biocaptors of polluting metals using a cavity microelectrode modified by HA-PEB systems, the adsorption kinetic and adsorption capacity were investigated. The SEM analysis showed that the presence of humic acid affected the PEB surface and caused the formation of a granular morphology. The maximum adsorption capacities （q max ） of PFHA, THA and YHA determined by adsorption isotherms were 91.31, 132.1 and 151.0 mg/g, respectively. Batch adsorption results showed that q max of Cd 2＋ , Zn 2＋ and Ni 2＋ on HA-PEB followed the order： THA-PEB YHA-PEB PFHA-PEB. The voltammograms obtained with HA-PEB modified cavity microelectrode showed the appearance of new redox couples reflecting the adsorption of HA on PEB. Metal-humic acid-polyaniline voltammograms were characterized by appearance of oxidation-reduction couples or reduction wave corresponding to metal. Finally, the result may be exploited to develop a biocaptor based on the cavity microelectrode amended by THA-PEB and YHA-PEB.展开更多
Gaseous peroxides play important roles in atmospheric chemistry. To understand the pathways of the formation and removal of peroxides, atmospheric peroxide concentrations and their controlling factors were measured fr...Gaseous peroxides play important roles in atmospheric chemistry. To understand the pathways of the formation and removal of peroxides, atmospheric peroxide concentrations and their controlling factors were measured from 7：00 to 20：00 in September, October, and November 2013 at a heavily trafficked residential site in Beijing, China, with average concentrations of hydrogen peroxide（H2O2） and methyl hydroperoxide（MHP） at 0.55 ppb and 0.063 ppb, respectively. H2O2 concentrations were higher in the afternoon and lower in the morning and evening, while MHP concentrations did not exhibit a regular diurnal pattern. Both H2O2 and MHP concentrations increased at dusk in most cases. Both peroxides displayed monthly variations with higher concentrations in September. These results suggested that photochemical activity was the main controlling factor on variations of H2O2 concentrations during the measurement period. Increasing concentrations of volatile organic compounds emitted by motor vehicles were important contributors to H2O2 and MHP enrichment. High levels of H2O2 and MHP concentrations which occurred during the measurement period probably resulted from the transport of a polluted air mass with high water vapor content passing over the Bohai Bay, China.展开更多
The frequent haze days around the Chinese capital of Beijing in recent years have aroused great attention owing to the detrimental effects on visibility and public health. To discover the potential health effects of t...The frequent haze days around the Chinese capital of Beijing in recent years have aroused great attention owing to the detrimental effects on visibility and public health. To discover the potential health effects of the haze, oxidative capacities of airborne particles collected in Beijing during haze and clear days were comparably assessed by a plasmid scission assay. Eleven water-soluble trace elements （As, Cd, Cr, Cu, Mn, Ni, Pb, V, Se, T1, and Zn） in the size-segregated airborne particles were quantitatively analyzed by inductively coupled plasma mass spectrometry, and most of the water- soluble trace elements were found to mainly concentrate in the fine particle size of 0.56-1.0 μm. In comparison with clear days, the mass concentrations of 11 analyzed water-soluble trace elements remarkably increased during haze days, and the oxidative capacities determined by the plasmid scission assay were markedly elevated accordingly during the haze days under the same dosage of particles as for those during clear days. Water-soluble trace elements in airborne particles, such as Cu, V, and particularly Zn, were found to have significantly positive correlations with the plasmid DNA damage rates. Because Cu, V, and Zn have been considered as bioavailable elements, the evident increase of these elements during haze days may be greatly harmful to human health.展开更多
A series of cellulose 3,5-dimethylphenylcarbamates （CDMPCs） with different degrees of substitution （DS） and degrees of polymerization （DP） were homogeneously synthesized in 1-allyl-3-methylimidazolium chloride ...A series of cellulose 3,5-dimethylphenylcarbamates （CDMPCs） with different degrees of substitution （DS） and degrees of polymerization （DP） were homogeneously synthesized in 1-allyl-3-methylimidazolium chloride （AmimC1）. Then, the CDMPCs were coated on silica gel and used as chiral stationary phases （CSPs）, and their chiral recognition abilities for seven racemates were evaluated by high performance liquid chromatography. The results showed that DS and DP of CDMPCs had a great influence on chiral recognition abilities of the CSPs. The CSPs with the DS ~ 1 gives a low chiral recognition to most racemates. On the contrast, the CSPs with the DS _〉 2 exhibited high chiral separation abilities. For example, six racemates could be separated on the CSP with CDMPC of DS ~ 2 （CSP-2）. Especially, for the enantioseparation of 1-（2-naphthyl） ethanol and Tr6ger＇s base, CSP-2 gave the highest separation ability in all of CSPs. On the other hand, when the DP of cellulose was in a range from 39 to 220, the chiral separation abilities of CDMPCs increased as the DP increased. This work demonstrates that the structure of cellulose esters such as DS and DP has important effect on their chiral separation ability, and therefore provides a practical method to design and prepare desirable CSPs for different racemates.展开更多
A dust deflation module was developed and coupled with the air quality modeling system RAMS-CMAQ to simultaneously treat all the major tropospheric aerosols（i.e.,organic and black carbons,sulfate,nitrate, ammonia,soi...A dust deflation module was developed and coupled with the air quality modeling system RAMS-CMAQ to simultaneously treat all the major tropospheric aerosols（i.e.,organic and black carbons,sulfate,nitrate, ammonia,soil dust,and sea salt）.Then the coupled system was applied to East Asia to simulate Asian dust aerosol generation,transport and dry/wet removal processes during 14-25 March 2002 when two strong dust storms occurred consecutively.To evaluate model performance and to analyze the observed features of dust aerosols over the East Asian region,model results were compared to concentrations of suspended particulate matter of 10μm or less(PM;;1-h intervals) at four remote Japanese stations and daily air pollution index （API） values for PM;at four large Chinese cities.The modeled values were generally in good agreement with observed data,and the model reasonably reproduced two dust storm outbreaks and generally predicted the dust onset and cessation times at each observation site.In addition,hourly averaged values of aerosol optical thickness（AOT） were calculated and compared with observations at four Aerosol Robotic Network （AERONET） stations to assess the model’s capability of estimating dust aerosol column burden.Analysis shows that modeled and observed AOT values were generally comparable and that the contribution of dust aerosols to AOT was significant only with regard to their source regions and their transport paths.展开更多
A novel 2,6-dimethyl-b-CD bonded and silica based HPLC chiral stationary phase（CSP） was prepared.The diphenylmethane diisocyanate（MDI） was applied for the first time in the immobilization of 2,6-dimethyl-b-CD onto...A novel 2,6-dimethyl-b-CD bonded and silica based HPLC chiral stationary phase（CSP） was prepared.The diphenylmethane diisocyanate（MDI） was applied for the first time in the immobilization of 2,6-dimethyl-b-CD onto the surface of aminized silica gel under mild conditions. The composite materials obtained were used as the CSP for chiral separation processes and this kind of CSP exhibits good enantioselectivity for a variety of chiral compounds under reversed-phase conditions.展开更多
文摘Essential oils(EOs)derived from medicinal plants are gaining recognition as sustainable alternatives to synthetic fungicides in the management of plant pathogens.This study investigates the chemical composition,chromatographic profile,and antifungal of Mentha rotundifolia essential oil against Fusarium oxysporum f.sp.albedinis(Foa),the pathogen responsible for Bayoud disease in date palm.The oil was extracted through hydrodistillation and characterized using thin-layer chromatography(TLC)and gas chromatography–mass spectrometry(GC-MS),revealing multiple fractions corresponding to terpenoid constituents and 23 chemical constituents,predominantly oxygenated monoterpenes(68.51%),with piperitenone oxide as the major component(62.53%).The antifungal efficacy was evaluated against ten(10)isolates of F.o.a across seven(07)concentrations different concentrations.(0;0.25;0.5;0.75;1;1.25;1.5μL/mL).The results obtained show a progressive decrease in the diameters of the colonies of F.o.a isolates by increasing the doses of EOMR.The percentage of inhibition varies from 7.82 to 83.41%;However,the dose of 1.75μL/mL showed 100%inhibition for all F.o.a isolates tested.These outcomes demonstrate the potential of M.rotundifolia essential oil as a natural,environmentally friendly antifungal agent,supporting its application in sustainable management strategies for Bayoud disease in date palm.
文摘Study of 1986 and 1987 heavy metal distribution in surface water of the Kuroshio area in the East China Sea showed regional and slight seasonal variations in distribution and concentration . Heavy metal levels in Taiwan Strait, the sea area north of Taiwan and the continental shelf are higher than those in the main axis of the Kuroshio . Dissolved Cu in summer and winter decreases with the increase of salinity , but dissolved Cd has no obvious change with salinity .
文摘Color mothball is a daily necessity in Southeast Asia. Mothball contained nearly 100% naphthalene or 100% p-dichlorobenzene. It was used to resist insects, mothproof and mildew with a special odor. In other words, the odor was thought unpleasant enough to drive animals away in repellent products. This research analyzed color mothball which was manufactured by C and N companies. The mothball was dyed with eight dyes and three essences of fragrance, respectively. The experiment of color fastness with UV-light test is to determine how much the color will fade, when it exposed to a known ultraviolet light source. In the last analysis, the experimental data from the spectrum of GC/MS described all kinds of structure on color mothball after 80 hours phototherapy treatment as shown in the content. This research reveals that color mothball can have better appearance and greater performance, to meet the requirements for customs and various applications.
基金support from the National Natural Science Foundation of China (No.20876157)
文摘An alkaline precipitation method was introduced to produce hydrous cerium oxides.The prepared powder was characterized by Brunauer-Emmett-Teller（BET） nitrogen adsorption-desorption,X-ray diffraction（XRD）,Fourier transform infrared（FTIR） spectrometry,and thermal gravimetry（TG） approaches.The adsorbent has a chemical formula of CeO2·nH2O（n 2） and a cubic fluorite-type structure after high temperature treatment.Adsorption capacity of different temperature treated hydrous cerium oxides does not directly correlate with BET specific surface area.Phosphate adsorption isotherms follow the Langmuir equation below the treatment temperature of 800°C.Phosphate adsorption causes no change on the structure of a hydrous cerium oxides,and no signs of CePO4 precipitates are found.The ion-exchanging structure of hydrous cerium oxide plays a fundamental role in phosphate adsorption.The structure is highly temperature resistant and forms adsorption sites which adsorb both water and some anions.Complete loss of adsorption ability cannot be achieved unless the treatment temperature is higher than 1200°C.Mechanism study shows that the adsorption of phosphates is mainly an anion-exchange process.
基金supported by the National Natural Science Foundation of China (Nos. 21475010, 61635003)Beijing Natural Science Foundation (No. 16L00065)State Key Laboratory Explosion Science and Technology (No. YBKT16-17)
文摘With outstanding analytical performance and portability, miniature mass spectrometer is one of the most powerful tools for in-situ analysis. The miniaturization of mass spectrometers has lasted for more than ten years, during which a number of miniature mass spectrometers employing different techniques have been developed. Small-in-size, working at relatively high pressure region and capable of performing tandem mass spectrometry, ion trap is the most widely used mass analyzer in miniature mass spectrometer systems. The recent development of miniature ion trap mass spectrometer systems in the last ten years was reviewed in this paper. These instruments adopt different atmospheric pressure interfaces （APIs）, which are membrane inlets （MIs）, discontinuous atmospheric pressure interface （DAPI） and continuous atmospheric pressure interface （CAPI）. This review emphasizes on the mini mass spectrometry （MS） system that can be handheld by one person, but not the field-able ones that are too large to be hand-portable.
基金Funded by 973 National Key Scientific Project Foundation (No.001CB610701) the University Key Laboratoty Foundation of Jiangshu Province (No.KJS03021)the Sixth Outstanding Talents Foundation.
文摘A new composition of Portland cement clinker was studied, in which KH, SM and IM was 0.98,2.4 and 2.4 respectively as well as its meal added 1%CuO （in mass）. Fired at 1 200℃,1 350℃,1 400℃ and 1 450℃ for 30 min, the resultant mineral phases component and mineral morphology were analyzed. The performances of the cement which was made of clinker burned at 1 450℃ and fly ash were determined. By means of QXRD, XRD and optical microscopy, it is shown that the clinker burnt at 1 450℃ has the larger size crystals and distinct crystal interface, in which the C3S content is 73.37% and the mineral phases is dominantly C3S, following by minor C2S, C3A and tetracalcium aluminoferrite. The results reveal that a new type of high C3S content clinker can completely be made by traditional temperature-time schedule. The performances of the cement produced from this clinker with addtion of 50% fly ash and 5% gupsum were in agreement with the 32.5 strength grade of Portland fly-ash cement. The results also show that the clinker has a significant effect of saving energy and utilizing waste slag.
基金funded by the National Science Foundation of China(41502144,41503034)the Foundation of the State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing(No.PRP/open-1612)+2 种基金the Fund of the Education Department of Sichuan Province(16ZA0075)the Youth Scientific Innovation Team of Hydrocarbon Accumulation and Geochemistry,Southwest Petroleum University(2015CXTD02)the Sichuan Province University Scientific Innovation Team Construction Project(USITCP)
文摘To investigate the influence of extractable organic matter （EOM） on pore evolution of lacustrine shales, Soxhlet extraction, using dichloromethane, was performed on a series of Chang 7 shale samples （Ordos Basin, China） with vitrinite reflectance of 0.64% to 1.34%. Low-pressure gas adsorption experiments were conducted on the samples before and after extraction. The pore structure parameters were calculated from the gas adsorption data. The results show complex changes to the pore volumes and surface areas after extraction. The pore development of both the initial and extracted samples is strongly controlled by total organic carbon （TOC） content. Micropores developed mainly in organic matter （OM）, while mesopores and macropores predominantly developed in fractions other than OM. The influence of EOM on micropores is stronger than on mesopores and macropores. Organic solvents with a higher boiling point should be used to explore the effect of EOM on pore structure in the future.
基金supported by the National Natural Science Foundation of China(Grant Nos.41772114,41402123)the CGS Research Fund of China(Grant Nos.J1901-33,J1803)the China Geological Survey(Grant No.DD20221817).
文摘Organic matter(OM)and minerals are major particle components of lacustrine shales.The influence of OM and minerals on pore space and structure in organic-rich oil-prone shales containing a large range of total organic carbon(TOC)contents is poorly understood.In this study,we investigated the variation in pore space and structure of low mature lacustrine shales in the Songliao Basin(NE China),based on a study of the mineralogy,petrography,geochemistry,and geophysical properties of shales.Different pore types make markedly different contributions to the mineral surface area(MSA)and pore volume(PV)of the shales.There exists a negative correlation between MSA/PV and TOC in mesopores(r^(2)=0.75/0.65)and macropores(r^(2)=0.74/0.68),and a positive correlation in micropores(r^(2)=0.59/0.64),which are associated with the variation of mineral and TOC contents.A positive relationship between the throat/pore ratio and TOC(r^(2)=0.82)shows an increase in throat radius and decrease in pore radius with increasing TOC content.This relationship is supported by the reduction in mean pore diameter(MPD)for large pores and increase in MPD for small pores.These variations are related to the decreased pores by quartz plus feldspar(Q+F)content,increased throats by clay minerals,an d enhanced pore-fill by OM.We propose that the variation of OM and minerals is a key control on the pore space and structure of low mature organic-rich oil-prone shales.
基金the financial assistance of the State Key Laboratory of explosion science and technology China (Grant No.YBKT17-06)
文摘Most of the structural alloys’applications are under static,dynamic,and cyclic forms of loading.Ti-5553 alloy in the beta phase field is being investigated to confirm the mechanism of deformation and phase transformation upon quasi-static and dynamic compression.The Ti-5553 alloy was heat-treated at 900℃ (almost 50℃ above beta transus temperature)for one hour of soaking time followed by air quenching to achieve a fullyβphase field.After that,Dynamic compression(DC)by Split Hopkinson Pressure Bar(SHPB)and Quasi-static compression(QSC)were performed at a strain rate of~10^3)/s and 10^(-3)/s,respectively.Recovered specimens were thoroughly examined by using different tools,such as an Optical microscope(OM),Scanning electron microscope(SEM),High-resolution transmission electron microscope(HRTEM),and Electron backscatter diffraction(EBSD)to get the reliable data for justification of logical conclusions.It is found that the dominating mode of deformation was dislocation slip along with twinning({332}<113>)to some extent in both of QSC and DC,but sliding&spalling of the grain boundary is observed more in the former.Stress-induced phase transformation,i.e.,βtoα"andβtoω,took place in the grains saturated with dislocation slips,where the former transformation occurred simultaneously with{332}<113>twinning,whileβtoωtransformation was completed when a set of two adjacent(110)_(β)planes covered±1/6th of the total separation distance between two(next to each other)(111)_(β)planes,by equal but opposite shear in(111)_(β)direction,and it caused 3%shrinkage of two closed packed(110)_(β)planes after transformation.
基金supported by the National Key R&D Program of China(No.2017YFA0605001)the National Natural Science Foundation of China(No.91547207)the Fund for Innovative Research Group of the National Natural Science Foundation of China(No.51721093)
文摘Water regulation of the Xiaolangdi Reservoir of the Yellow River was chosen as a case to investigate variations in concentrations and bioavailability of heavy metals caused by water conservancy projects in rivers. Water and suspended sediment（SPS） samples were collected at downstream sampling sites along the river during this period. Concentrations and speciation of Zn, Cr, Cu, Ni, and Pb in water and SPS samples were analyzed, and their bioaccumulation was studied with Daphnia magna. This study indicated that the exchangeable and carbonatebound fractions of heavy metals in SPS decreased along the studied stretch, and the dissolved heavy metal concentrations increased along the river with 1.6–15 folds. This is because sediment resuspension increased along the river during water regulation, giving rise to the increase of heavy metal release from SPS. The dissolved Zn, Cu, Ni, and Pb concentrations were significantly positively correlated with SPS concentrations, and their increase along the river was greater than Cr. The body burdens of heavy metals in D. magna exposed into samples collected from the reservoir outlet were 1.3–3.0 times lower than those from downstream stations, suggesting that the heavy metal bioavailability increased during water regulation.This should be considered in the reservoir operation.
基金The National Natural Science Foundation of China under contract No.61471024the National Marine Technology Program for Public Welfare under contract No.201505002。
文摘A new paradigm for ship detection in polarimetric synthetic aperture radar(Pol-SAR)image is presented.We firstly utilize the scattering similarity parameters to investigate the differences of scattering mechanism between ships and sea clutter.Based on these differences,we propose a novel ship detection metric,denoted as the scattering similarity based metric(SSM),to conduct ship detection task.The distribution model of SSM metric is investigated and modeled by kernel density estimation(KDE).Based on the statistical distribution,an adaptive constant false alarm rate(CFAR)detection scheme is implemented.We compare the proposed SSM with two classic polarimetric metrics,i.e.,the polarimetric cross-entropy(PCE)and the reflection symmetry metric(RSM).The experimental results conducted on C-band RADARSAT-2 Pol-SAR data demonstrate the feasibility and advantage of the proposed SSM metric both in sea clutter modeling and in ship detection.
基金co-funded by the National Science Foundation of China(41972161,41502144)the Petro China Science and Technology Special Project(2011A-0203)。
文摘To investigate pore characteristics and the factors controlling lacustrine shales,geochemical,mineralogical and petrophysical experiments were performed on 23 shale samples from the Qingshankou Formation of the Songliao Basin,China.A comparison of mercury injection capillary pressure(MICP)and low-temperature N2 adsorption pore-size distribution showed that MICP has a higher pore-size distribution(PSD)line in its overlapping pore diameter range,which may be elevated by the higher pressure of MICP.Therefore,in the overlapping range,low-temperature N2 adsorption data were preferred in pore characterization.Negative correlations were observed between pore volumes and TOC content,indicating organic matter pores are not well-developed in the studied samples.This may be related to their low grade of maturity and type I kerogens.There existed negative relationships between pore volumes and S1,which illustrated that liquid hydrocarbons occupied some pore space.Micropore volume had a better correlation with S1 than mesopore and macropore volumes,which suggests that liquid hydrocarbons preferentially occur in micropores.No obvious relationships between pore volumes and quartz or feldspar were observed,while pore volumes increased with the increasing clay mineral content.These relationships indicate that intraparticle pores in clay minerals represent the principal pore type.
基金Supported by Open Foundation of Key Laboratory of Ministry of Education for TCM Viscera-State Theory and Applications,Liaoning University of Traditional Chinese Medicine(ZYZX1709)Project of Education Department of Liaoning Province(L201606)China Postdoctoral Science Foundation(2013M530945)
文摘[Objectives] The aim of this work was to compare the inhibitory effects of different water-soluble extracts of ginseng on hydroxyl radical. [Methods]The water-soluble effective parts of ginseng were extracted by orthogonal test,the hydroxyl radical scavenging rate of each extract was determined by salicylic acid method,and the extraction process of the optimum hydroxyl radical inhibitor was optimized using variance analysis and cluster analysis. [Results] A total of 16 samples were prepared. Among them,the sample No. 12 had the highest hydroxyl radical scavenging rate,and the inhibition rate reached 105. 08% at the concentration of 1 g/L. [Conclusions] Ginseng water extract contained hydroxyl radical scavenger,of which the optimum extraction process was as follows: p H of 8,solid to liquid ratio of 1∶ 10,extraction temperature of 4℃,extraction time of 12 h and extraction times of 3.
文摘The adsorption capacities of new humic acids isolated from Yakouren forest （YHA） and Sahara （Tamenrasset： THA） soils （Algeria） and commercial humic acid （PFHA） on polyaniline emeraldine base （PEB） were studied at pH 6.6. Also the adsorption of heavy metals such as Cd 2＋ , Zn 2＋ and Ni 2＋ on humic acid-polyaniline systems （HA-PEB） was investigated at the same conditions. HA-PEB compounds were characterized by scanning electron microscopy （SEM）, infrared spectrometry and cavity microelectrode. In addition, batch adsorption and cavity microelectrode were used in the adsorption study of Cd 2＋ , Zn 2＋ and Ni 2＋ on HA-PEB. To develop biocaptors of polluting metals using a cavity microelectrode modified by HA-PEB systems, the adsorption kinetic and adsorption capacity were investigated. The SEM analysis showed that the presence of humic acid affected the PEB surface and caused the formation of a granular morphology. The maximum adsorption capacities （q max ） of PFHA, THA and YHA determined by adsorption isotherms were 91.31, 132.1 and 151.0 mg/g, respectively. Batch adsorption results showed that q max of Cd 2＋ , Zn 2＋ and Ni 2＋ on HA-PEB followed the order： THA-PEB YHA-PEB PFHA-PEB. The voltammograms obtained with HA-PEB modified cavity microelectrode showed the appearance of new redox couples reflecting the adsorption of HA on PEB. Metal-humic acid-polyaniline voltammograms were characterized by appearance of oxidation-reduction couples or reduction wave corresponding to metal. Finally, the result may be exploited to develop a biocaptor based on the cavity microelectrode amended by THA-PEB and YHA-PEB.
基金supported by the International Cooperation Project of MOST(No.2012DFG90290)the National Natural Science Foundation of China(No.4225001046)+1 种基金National Department Public Benefit Research Foundation(No.201509014)the Basic Foundation for Public Benefit-Research Academies from Centre Government(No.2010KYYW02)
文摘Gaseous peroxides play important roles in atmospheric chemistry. To understand the pathways of the formation and removal of peroxides, atmospheric peroxide concentrations and their controlling factors were measured from 7：00 to 20：00 in September, October, and November 2013 at a heavily trafficked residential site in Beijing, China, with average concentrations of hydrogen peroxide（H2O2） and methyl hydroperoxide（MHP） at 0.55 ppb and 0.063 ppb, respectively. H2O2 concentrations were higher in the afternoon and lower in the morning and evening, while MHP concentrations did not exhibit a regular diurnal pattern. Both H2O2 and MHP concentrations increased at dusk in most cases. Both peroxides displayed monthly variations with higher concentrations in September. These results suggested that photochemical activity was the main controlling factor on variations of H2O2 concentrations during the measurement period. Increasing concentrations of volatile organic compounds emitted by motor vehicles were important contributors to H2O2 and MHP enrichment. High levels of H2O2 and MHP concentrations which occurred during the measurement period probably resulted from the transport of a polluted air mass with high water vapor content passing over the Bohai Bay, China.
基金supported by the"Strategic Priority Research Program-Formation Mechanism and Control Strategies of Haze in China"of the Chinese Academy of Sciences(No.XDB05010100),the National Basic Research Program(973)of China(No.2013CB228503,2010CB732304)
文摘The frequent haze days around the Chinese capital of Beijing in recent years have aroused great attention owing to the detrimental effects on visibility and public health. To discover the potential health effects of the haze, oxidative capacities of airborne particles collected in Beijing during haze and clear days were comparably assessed by a plasmid scission assay. Eleven water-soluble trace elements （As, Cd, Cr, Cu, Mn, Ni, Pb, V, Se, T1, and Zn） in the size-segregated airborne particles were quantitatively analyzed by inductively coupled plasma mass spectrometry, and most of the water- soluble trace elements were found to mainly concentrate in the fine particle size of 0.56-1.0 μm. In comparison with clear days, the mass concentrations of 11 analyzed water-soluble trace elements remarkably increased during haze days, and the oxidative capacities determined by the plasmid scission assay were markedly elevated accordingly during the haze days under the same dosage of particles as for those during clear days. Water-soluble trace elements in airborne particles, such as Cu, V, and particularly Zn, were found to have significantly positive correlations with the plasmid DNA damage rates. Because Cu, V, and Zn have been considered as bioavailable elements, the evident increase of these elements during haze days may be greatly harmful to human health.
基金financially supported by the National Natural Science Foundation of China(Nos.5110316721174151 and 51425307)
文摘A series of cellulose 3,5-dimethylphenylcarbamates （CDMPCs） with different degrees of substitution （DS） and degrees of polymerization （DP） were homogeneously synthesized in 1-allyl-3-methylimidazolium chloride （AmimC1）. Then, the CDMPCs were coated on silica gel and used as chiral stationary phases （CSPs）, and their chiral recognition abilities for seven racemates were evaluated by high performance liquid chromatography. The results showed that DS and DP of CDMPCs had a great influence on chiral recognition abilities of the CSPs. The CSPs with the DS ~ 1 gives a low chiral recognition to most racemates. On the contrast, the CSPs with the DS _〉 2 exhibited high chiral separation abilities. For example, six racemates could be separated on the CSP with CDMPC of DS ~ 2 （CSP-2）. Especially, for the enantioseparation of 1-（2-naphthyl） ethanol and Tr6ger＇s base, CSP-2 gave the highest separation ability in all of CSPs. On the other hand, when the DP of cellulose was in a range from 39 to 220, the chiral separation abilities of CDMPCs increased as the DP increased. This work demonstrates that the structure of cellulose esters such as DS and DP has important effect on their chiral separation ability, and therefore provides a practical method to design and prepare desirable CSPs for different racemates.
基金supported by the National Basic Research Program of China(2007CB407303)the Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-YW-Q11-04)the National Natural Science Foundation of China(Grant No.41005064).
文摘A dust deflation module was developed and coupled with the air quality modeling system RAMS-CMAQ to simultaneously treat all the major tropospheric aerosols（i.e.,organic and black carbons,sulfate,nitrate, ammonia,soil dust,and sea salt）.Then the coupled system was applied to East Asia to simulate Asian dust aerosol generation,transport and dry/wet removal processes during 14-25 March 2002 when two strong dust storms occurred consecutively.To evaluate model performance and to analyze the observed features of dust aerosols over the East Asian region,model results were compared to concentrations of suspended particulate matter of 10μm or less(PM;;1-h intervals) at four remote Japanese stations and daily air pollution index （API） values for PM;at four large Chinese cities.The modeled values were generally in good agreement with observed data,and the model reasonably reproduced two dust storm outbreaks and generally predicted the dust onset and cessation times at each observation site.In addition,hourly averaged values of aerosol optical thickness（AOT） were calculated and compared with observations at four Aerosol Robotic Network （AERONET） stations to assess the model’s capability of estimating dust aerosol column burden.Analysis shows that modeled and observed AOT values were generally comparable and that the contribution of dust aerosols to AOT was significant only with regard to their source regions and their transport paths.
文摘A novel 2,6-dimethyl-b-CD bonded and silica based HPLC chiral stationary phase（CSP） was prepared.The diphenylmethane diisocyanate（MDI） was applied for the first time in the immobilization of 2,6-dimethyl-b-CD onto the surface of aminized silica gel under mild conditions. The composite materials obtained were used as the CSP for chiral separation processes and this kind of CSP exhibits good enantioselectivity for a variety of chiral compounds under reversed-phase conditions.
