In order to improve the hydriding and dehydriding kinetics of the Mg2Ni-type alloys,Ni in the alloy is substituted by element Co. The nanocrystalline and amorphous Mg2Ni-type Mg2Ni1-xCox (x=0,0.1,0.2,0.3,0.4) alloys w...In order to improve the hydriding and dehydriding kinetics of the Mg2Ni-type alloys,Ni in the alloy is substituted by element Co. The nanocrystalline and amorphous Mg2Ni-type Mg2Ni1-xCox (x=0,0.1,0.2,0.3,0.4) alloys were synthesized by melt-spinning technique. The structures of the as-cast and spun alloys were studied with an X-ray diffractometer (XRD) and a high resolution transmission electronic microscope (HRTEM). An investigation on the thermal stability of the as-spun alloys was carried out with a differential scanning calorimeter (DSC). The hydrogen absorption and desorption kinetics of the alloys were measured with an automatically controlled Sieverts apparatus. The results demonstrate that the substitution of Co for Ni does not alter the major phase of Mg2Ni but results in the formation of secondary phase MgCo2. No amorphous phase is detected in the as-spun Co-free alloy,but a certain amount of amorphous phase is clearly found in the as-spun Co-containing alloys. The substitution of Co for Ni exerts a slight influence on the hydriding kinetics of the as-spun alloy. However,it dramatically enhances the dehydriding kinetics of the as-cast and spun alloys. As Co content (x) increases from 0 to 0.4,the hydrogen desorption capacity increases from 0.19% to 1.39% (mass fraction) in 20 min for the as-cast alloy,and from 0.89% to 2.18% (mass fraction) for the as-spun alloy (30 m/s).展开更多
In this work,a comprehensive comparison regarding the impacts of M(M=Cu,Co,Mn)substitution for Ni on the structures and the hydrogen storage kinetics of the nanocrystalline and amorphous Mg20Ni10-xMx(M=Cu,Co,Mn; x=0-4...In this work,a comprehensive comparison regarding the impacts of M(M=Cu,Co,Mn)substitution for Ni on the structures and the hydrogen storage kinetics of the nanocrystalline and amorphous Mg20Ni10-xMx(M=Cu,Co,Mn; x=0-4)alloys prepared by melt spinning has been carried out.The analysis of XRD and TEM reveals that the as-spun(M=None,Cu)alloys display an entire nanocrystalline structure,whereas the as-spun(M=Co,Mn)alloys hold a mixed structure of nanocrystalline and amorphous structure when M content x=4,indicating that the substitution of M(M=Co,Mn)for Ni facilitates the glass formation in the Mg2Ni-type alloy.Besides,all the as-spun alloys have a major phase of Mg2Ni but M(M=Co,Mn)substitution brings on the formation of some secondary phases,MgCo2 and Mg phases for M=Co as well as MnNi and Mg phases for M=Mn.Based upon the measurements of the automatic Sieverts apparatus and the automatic galvanostatic system,the impacts engendered by M(M=Cu,Co,Mn)substitution on the gaseous and electrochemical hydrogen storage kinetics of the alloys appear to be evident.The gaseous hydriding kinetics of the alloys first rises and then declines with the growing of M(M=Cu,Co,Mn)content.Particularly,the M(M= Mn)substitution results in a sharp drop in the hydriding kinetics when x=4.The M(M=Cu,Co,Mn)substitution ameliorates the dehydriding kinetics dramatically in the order(M=Co)>(M=Mn)>(M=Cu).The electrochemical kinetics of the alloys visibly grows with M content rising for(M=Cu,Co),while it first increases and then declines for(M=Mn).展开更多
The feldspar-based microwave dielectric ceramic with low relative permittivity(εr)and excellent mechanical properties has attracted much attention in the fifth-generation wireless communication technology.In this wor...The feldspar-based microwave dielectric ceramic with low relative permittivity(εr)and excellent mechanical properties has attracted much attention in the fifth-generation wireless communication technology.In this work,a series of microwave dielectric ceramic SrAl_(2-x)Ga_(x)Si_(2)O_(8)(0.1≤x≤2.0)was synthesized using the traditional solid-state method.X-ray diffraction pattern indicates that Ga^(3+)can be dissolved into Al^(3+),forming a solid solution.Meanwhile,substitution of Ga^(3+)for Al^(3+)can promote the space group transition from I2/c(0.1≤x≤1.4)to P21/a(1.6≤x≤2.0)with coefficient of thermal expansion(CTE)increasing from 2.9×10^(-6)℃^(-1) to 5.2×10^(-6)℃^(-1).During this substitution,the phase transition can significantly improve the structural symmetry to enhance the dielectric properties and mechanical properties.Rietveld refinement results indicate that Ga^(3+)averagely occupied four Al^(3+)compositions to form solid solution.All ceramics have a dense microstructure and high relative density above 95%.An ultralower of 5.8 was obtained at x=1.6 composition with high quality factor(Q´f)of 50700 GHz and negative temperature coefficients of resonant frequency(tf)of approximately−35×10^(-6)℃^(-1).The densification temperature can be reduced to 940℃by adding 4%(in mass)LiF,resulting in good chemical compatibility with Ag electrode.Meanwhile,negativetf can be tuned to near-zero(+3.7×10^(-6)℃^(-1))by adding CaTiO_(3) ceramic.展开更多
Utilizing mine solid waste as a partial cement substitute(CS)to develop new cementitious materials is a significant technological innovation that will decrease the expenses associated with filling mining.To realize th...Utilizing mine solid waste as a partial cement substitute(CS)to develop new cementitious materials is a significant technological innovation that will decrease the expenses associated with filling mining.To realize the resource utilization of magnesium slag(MS)and blast furnace slag(BFS),the effects of different contents of MS and BFS as partial CSs on the deformation and energy characteristics of cemented tailings backfill on different curing ages(3,7,and 28 d)were discussed.Meanwhile,the destabilization failure energy criterion of the backfill was established from the direction of energy change.The results show that the strength of all backfills increased with increasing curing age,and the strengths of the backfills exceeded 1.342 MPa on day 28.The backfill with 50%BFS+50%cement has the best performance in mechanical properties(the maximum strength can reach 6.129 MPa)and is the best choice among these CS combinations.The trend in peak strain and elastic modulus of the backfill with increasing curing age may vary depending on the CS combination.The energy index at peak stress of the backfill with BFS as a partial CS was significantly higher than that of the backfill under other CS combinations.In contrast,the enhancement of the energy index when MS was used as a partial CS was not as significant as BFS.Sharp changes in the energy consumption ratio after continuous smooth changes can be used as a criterion for destabilization and failure of the backfill.The research results can provide guidance for the application of MS and BFS as partial CSs in mine filling.展开更多
A method, doping WC with La(NO 3) 3, of producing cemented carbide with rare earth was introduced. The effects of lanthanum on the mechanical properties and microstructure of WC 9(Co 75%Ni) cemented carbide were studi...A method, doping WC with La(NO 3) 3, of producing cemented carbide with rare earth was introduced. The effects of lanthanum on the mechanical properties and microstructure of WC 9(Co 75%Ni) cemented carbide were studied and a rock drilling experiment was carried out.The experimental results show that both transverse rupture strength (TRS) and hardness of WC 9(Co 75%Ni) rare earth cemented carbides can match that of WC 9Co cemented carbide, when La 2O 3 / (Co+Ni) ratio is 0.3%, the abnormal growth of WC grain in the cemented carbide can be restrained effectively, the homogeneity of grain size in microstructure and the wear resistance are improved, which can be matchable to that of WC 9Co cemented carbide for mining.展开更多
We report on the application of Laser Induced Breakdown Spectroscopy(LIBS)technique to the study of Ca,P,Zn and Sr evolutions for adult caries-affected teeth using nanosecond laser pulses.The aim of this work is to be...We report on the application of Laser Induced Breakdown Spectroscopy(LIBS)technique to the study of Ca,P,Zn and Sr evolutions for adult caries-affected teeth using nanosecond laser pulses.The aim of this work is to better understand the behaviors of Zn and Sr as trace-elements in the caries eruption with respect to the behaviors of one of the main compounds of the hydroxyapatite crystal which is the calcium.The study was focused on the investigation of these elements’evolutions from three parts of the enamel surfaces of twenty two adult caries-affected teeth;the healthy part,the dental plaque part and the caries-affected part.The decrease rates of Zn,Sr and P was,also,compared to the Ca one.Comparison concerned normalized emission line intensities.For every species,normalization was done relatively to the emission line intensities of the healthy part.Results showed that abundances of these elements decrease similarly from the healthy parts to the affected-caries parts.The higher decrease rate was noticed for the calcium.The evolutions of Zn and Sr for the three parts of the teeth surfaces cannot inform about the substitution of the calcium by these trace-elements,however the comparison of their decrease rates to the calcium one can be considered as a valuable index of this substitution.展开更多
One of the impediments in the genetic improvement of cotton fiber is the paucity of information about genes associated with fiber development.Availability of chromosome arm substitution line CS-
A new kind of polyacrylamide derivate, hydroximic polyacrylamide (HPAM), was prepared from polyacrylamide (PAM) with hydroxylamine hydrochloride in KOH/alcohol solution. Based on colorimetric method in the measurement...A new kind of polyacrylamide derivate, hydroximic polyacrylamide (HPAM), was prepared from polyacrylamide (PAM) with hydroxylamine hydrochloride in KOH/alcohol solution. Based on colorimetric method in the measurement of C 7 9 alkyl hydroximic acid, the substitution degree of HPAM was determined by selecting octyl hydroximic acid as a primary standard substance. The effects of temperature, the amount of hydroxylamine and potassium hydroxide, and the reaction time on the reaction are discussed. HPAM with 5.78% substitution of degree was acquired by optimizing the reaction conditions. IR spectra revealed that tautomerism appears in the HPAM, and that HPAM exists in both the forms of hydroxamic type and hydroximic type, and the latter type can easily lead to the forming of intramolecular hydrogen bond.展开更多
The simulations of Cr atom substitution character during the formation of L12 and DO22 phases in Ni-Cr-Al alloy were performed at 873 K based on microscopic phase-field model. It is found that the substitution of Cr i...The simulations of Cr atom substitution character during the formation of L12 and DO22 phases in Ni-Cr-Al alloy were performed at 873 K based on microscopic phase-field model. It is found that the substitution of Cr is affected by Cr and Al contents and limits of occupation probabilities of Cr atom in L12 phase are present. The precipitate is single L12 phase when the component is less than the limit, Cr atoms substitute the Al sublattices in Ll2 phase, and both of atoms Al and Cr occupy the β-sites and complex phases Ni3（Al1-xCrx） are formed; Cr atoms enter Ni sites when Al and Cr contents exceed the limit, and substitute β-sites or both of α- and β-sites. The DO22 phase is formed at the boundary of Ll2 phase.展开更多
The genetic base that cotton breeders commonly use to improve Upland cultivars is very narrow.The AD-genome species Gossypium barbadense,G.tomentosum,and G.mustelinum are part of
Being as unique nonlinear components of block ciphers,substitution boxes（S-boxes） directly affect the security of the cryptographic systems.It is important and difficult to design cryptographically strong S-boxes th...Being as unique nonlinear components of block ciphers,substitution boxes（S-boxes） directly affect the security of the cryptographic systems.It is important and difficult to design cryptographically strong S-boxes that simultaneously meet with multiple cryptographic criteria such as bijection,non-linearity,strict avalanche criterion（SAC）,bits independence criterion（BIC）,differential probability（DP） and linear probability（LP）.To deal with this problem,a chaotic S-box based on the artificial bee colony algorithm（CSABC） is designed.It uses the S-boxes generated by the six-dimensional compound hyperchaotic map as the initial individuals and employs ABC to improve their performance.In addition,it considers the nonlinearity and differential uniformity as the fitness functions.A series of experiments have been conducted to compare multiple cryptographic criteria of this algorithm with other algorithms.Simulation results show that the new algorithm has cryptographically strong S-box while meeting multiple cryptographic criteria.展开更多
Nine 5 (β substituted stylryl) salicyladehyde derivatives were prepared by PTC Witting reactions in the paper . The stereochemistry of the Witting reactions and the substituted effect on the UV spectra of salicylad...Nine 5 (β substituted stylryl) salicyladehyde derivatives were prepared by PTC Witting reactions in the paper . The stereochemistry of the Witting reactions and the substituted effect on the UV spectra of salicyladehyde derivaties have been reported . It was observed that the spectra undergo a red shift as the conjugative effect of substituted becomes stronger . A good linear relationship between the shift of UV of p substituted compounds and conjugation effect was obtained.It showed that the Hammett equation may be applied to the UV frequencies of the title compounds.展开更多
In nature, iron cations in magnetite are usually isomorphically substituted by divalent (Co, Ni, Zn, Cu, Mn, etc.), trivalent (Al, V, Cr, etc.) and tetravalent (Ti) cations while maintaining the spinel structure. Some...In nature, iron cations in magnetite are usually isomorphically substituted by divalent (Co, Ni, Zn, Cu, Mn, etc.), trivalent (Al, V, Cr, etc.) and tetravalent (Ti) cations while maintaining the spinel structure. Some of the substituting cations, e.g. Cr3+, V3+ and Mn2+, improve the catalytic activity of magnetite in heterogeneous Fenton reaction through the enhancement of hydroxyl radical OH production and the pollutant adsorption.展开更多
The root mean square(RMS) difference of time-lapse seismic amplitudes is routinely used to identify the substituted fluid type in a reservoir during oil field production and recovery. By a time-lapse seismic method, w...The root mean square(RMS) difference of time-lapse seismic amplitudes is routinely used to identify the substituted fluid type in a reservoir during oil field production and recovery. By a time-lapse seismic method, we study the effects of fluid substitution in a physical model, which is an analogy of the three-dimensional inhomogeneous reservoir. For a weak inhomogeneous medium, gas/oil substitution results in positive anomalies in the reservoir layers, and negative anomalies below the bottom of the reservoir layers; while water/oil substitution causes only weak variations in the reservoir layers, but positive anomalies below the bottom of the reservoir layers. For the strong inhomogeneous medium, no matter what kind of fluid substitution(gas/oil or water/oil), there are significant anomalies in seismic amplitude difference attributes both in and below the reservoir layers. Therefore, for weak inhomogeneous media, such as tight sandstone or thin interbedded layers, the RMS amplitude difference attributes can be used to monitor fluid changes and predict the drilling direction; for inhomogeneous medium with karst carves or fractures, it is difficult to accurately determine the distribution of fluids with the RMS amplitude difference attributes.展开更多
Five kinds of agricultural castoffs, such as sawdust and powder of coconut coir, were used as growing media to substitute the peat moss for potted Cyclamen percicum. It showed that most of the substitute media could f...Five kinds of agricultural castoffs, such as sawdust and powder of coconut coir, were used as growing media to substitute the peat moss for potted Cyclamen percicum. It showed that most of the substitute media could fit for the growth of the root system without disturbing the spatial development of the root. The root activities of the plants in substitute media were all higher or not significantly lower than that in the contrast peat moss （PM）. The substitute media might not make adverse effects on the biosynthesis of chlorophyll of C. percicum leaves, and the nutrient components contained in the substitute media itself was none of the content of mineral elements in the leaves. The morphological indexes of C. percicum plants growing in the substitute media except in the powder of coconut coir （PCC） were all better than those in the contrast PM. The synthetically evaluation index of the plant showed that the sawdust, the powder of maize core, the powder of soybean stalk, the powder of peanut hull could take place the peat moss totally in C. percicum industrialization cultivation.展开更多
Detect the change of the Expression of oncoprotein on the Chinese hamster lung cells (V79 cells) which effect with two main district of China and four alternative chrysotile fiber to investigate the factors of lung ca...Detect the change of the Expression of oncoprotein on the Chinese hamster lung cells (V79 cells) which effect with two main district of China and four alternative chrysotile fiber to investigate the factors of lung cancer. V79 cells were exposed to the suspension of Chrysotile and its substitute with different powder content, the survival rate of cells was monitored by MTT. After 48 h, the location, distribution and expression of Survivin, Cap43, Bcl-2, p16 and p53 in V79 cell were examined by immunohistochemistry and compared. In the six kinds of powder, the inhibition of rockwool on the growth of cells was weakest, the inhibition of Chrysotile from Xinkang Sichuan and Southern Shanxi on the growth of cells was strongest. Chrysotile from Xinkang Sichuan, Chrysotile from Southern Shanxi, glass fiber, ceramic fiber, rockwool and wollastonite had a certain influence on the survival rate of V79 cells. As the concentration of powder increased the survival rate of cells decreased, which showed dose-effect relationship. The expression of Survivin, Cap43 and Bcl-2 was upregulated and the expression of P16 and P53 was downregulated in V79 cells, which was obviously in the powder suspension of Chrysotile from Southern Shanxi and Xinkang Sichuan and glass fiber. The expression was mainly in cytoplasm. The influence of different kind of powder on the cells differed in degree. Chrysotile and its substitute can induce the development of cancer by upregulating the expression of Survivin, Cap43 and Bcl-2 and downregulating the expression of p16 and p53.展开更多
As it is known a complete coverage of cotton(Gossypium hirsutum L.) genome with hypoaneuploids is not still realized.Therefore the detection of new types of aneuploids especially in different cytogenetic collections i...As it is known a complete coverage of cotton(Gossypium hirsutum L.) genome with hypoaneuploids is not still realized.Therefore the detection of new types of aneuploids especially in different cytogenetic collections is very useful.In Uzbekistan,long-term investigations towards development展开更多
基金Project(2006AA05Z132) supported by the National High-tech Research and Development Program of ChinaProjects(50871050, 50961009) supported by the National Natural Science Foundation of China+1 种基金Project(2010ZD05) supported by the Natural Science Foundation of Inner Mongolia, ChinaProject(NJzy08071) supported by the High Education Science Research Program of Inner Mongolia, China
文摘In order to improve the hydriding and dehydriding kinetics of the Mg2Ni-type alloys,Ni in the alloy is substituted by element Co. The nanocrystalline and amorphous Mg2Ni-type Mg2Ni1-xCox (x=0,0.1,0.2,0.3,0.4) alloys were synthesized by melt-spinning technique. The structures of the as-cast and spun alloys were studied with an X-ray diffractometer (XRD) and a high resolution transmission electronic microscope (HRTEM). An investigation on the thermal stability of the as-spun alloys was carried out with a differential scanning calorimeter (DSC). The hydrogen absorption and desorption kinetics of the alloys were measured with an automatically controlled Sieverts apparatus. The results demonstrate that the substitution of Co for Ni does not alter the major phase of Mg2Ni but results in the formation of secondary phase MgCo2. No amorphous phase is detected in the as-spun Co-free alloy,but a certain amount of amorphous phase is clearly found in the as-spun Co-containing alloys. The substitution of Co for Ni exerts a slight influence on the hydriding kinetics of the as-spun alloy. However,it dramatically enhances the dehydriding kinetics of the as-cast and spun alloys. As Co content (x) increases from 0 to 0.4,the hydrogen desorption capacity increases from 0.19% to 1.39% (mass fraction) in 20 min for the as-cast alloy,and from 0.89% to 2.18% (mass fraction) for the as-spun alloy (30 m/s).
基金Projects(51161015,51371094)supported by National Natural Science Foundations of ChinaProject(2011ZD10)supported by Natural Science Foundation of Inner Mongolia,China
文摘In this work,a comprehensive comparison regarding the impacts of M(M=Cu,Co,Mn)substitution for Ni on the structures and the hydrogen storage kinetics of the nanocrystalline and amorphous Mg20Ni10-xMx(M=Cu,Co,Mn; x=0-4)alloys prepared by melt spinning has been carried out.The analysis of XRD and TEM reveals that the as-spun(M=None,Cu)alloys display an entire nanocrystalline structure,whereas the as-spun(M=Co,Mn)alloys hold a mixed structure of nanocrystalline and amorphous structure when M content x=4,indicating that the substitution of M(M=Co,Mn)for Ni facilitates the glass formation in the Mg2Ni-type alloy.Besides,all the as-spun alloys have a major phase of Mg2Ni but M(M=Co,Mn)substitution brings on the formation of some secondary phases,MgCo2 and Mg phases for M=Co as well as MnNi and Mg phases for M=Mn.Based upon the measurements of the automatic Sieverts apparatus and the automatic galvanostatic system,the impacts engendered by M(M=Cu,Co,Mn)substitution on the gaseous and electrochemical hydrogen storage kinetics of the alloys appear to be evident.The gaseous hydriding kinetics of the alloys first rises and then declines with the growing of M(M=Cu,Co,Mn)content.Particularly,the M(M= Mn)substitution results in a sharp drop in the hydriding kinetics when x=4.The M(M=Cu,Co,Mn)substitution ameliorates the dehydriding kinetics dramatically in the order(M=Co)>(M=Mn)>(M=Cu).The electrochemical kinetics of the alloys visibly grows with M content rising for(M=Cu,Co),while it first increases and then declines for(M=Mn).
基金National Natural Science Foundation of China (52302140)Major Scientific and Technological Innovation Project of Wenzhou (ZG2023040, ZG2023042)Joint Funds of the National Natural Science Foundation of China Key Program (U21B2068)。
文摘The feldspar-based microwave dielectric ceramic with low relative permittivity(εr)and excellent mechanical properties has attracted much attention in the fifth-generation wireless communication technology.In this work,a series of microwave dielectric ceramic SrAl_(2-x)Ga_(x)Si_(2)O_(8)(0.1≤x≤2.0)was synthesized using the traditional solid-state method.X-ray diffraction pattern indicates that Ga^(3+)can be dissolved into Al^(3+),forming a solid solution.Meanwhile,substitution of Ga^(3+)for Al^(3+)can promote the space group transition from I2/c(0.1≤x≤1.4)to P21/a(1.6≤x≤2.0)with coefficient of thermal expansion(CTE)increasing from 2.9×10^(-6)℃^(-1) to 5.2×10^(-6)℃^(-1).During this substitution,the phase transition can significantly improve the structural symmetry to enhance the dielectric properties and mechanical properties.Rietveld refinement results indicate that Ga^(3+)averagely occupied four Al^(3+)compositions to form solid solution.All ceramics have a dense microstructure and high relative density above 95%.An ultralower of 5.8 was obtained at x=1.6 composition with high quality factor(Q´f)of 50700 GHz and negative temperature coefficients of resonant frequency(tf)of approximately−35×10^(-6)℃^(-1).The densification temperature can be reduced to 940℃by adding 4%(in mass)LiF,resulting in good chemical compatibility with Ag electrode.Meanwhile,negativetf can be tuned to near-zero(+3.7×10^(-6)℃^(-1))by adding CaTiO_(3) ceramic.
基金Projects(52274108,U2341265)supported by the National Natural Science Foundation of ChinaProject(2022YFC2904103)supported by the National Key Research and Development Program of China。
文摘Utilizing mine solid waste as a partial cement substitute(CS)to develop new cementitious materials is a significant technological innovation that will decrease the expenses associated with filling mining.To realize the resource utilization of magnesium slag(MS)and blast furnace slag(BFS),the effects of different contents of MS and BFS as partial CSs on the deformation and energy characteristics of cemented tailings backfill on different curing ages(3,7,and 28 d)were discussed.Meanwhile,the destabilization failure energy criterion of the backfill was established from the direction of energy change.The results show that the strength of all backfills increased with increasing curing age,and the strengths of the backfills exceeded 1.342 MPa on day 28.The backfill with 50%BFS+50%cement has the best performance in mechanical properties(the maximum strength can reach 6.129 MPa)and is the best choice among these CS combinations.The trend in peak strain and elastic modulus of the backfill with increasing curing age may vary depending on the CS combination.The energy index at peak stress of the backfill with BFS as a partial CS was significantly higher than that of the backfill under other CS combinations.In contrast,the enhancement of the energy index when MS was used as a partial CS was not as significant as BFS.Sharp changes in the energy consumption ratio after continuous smooth changes can be used as a criterion for destabilization and failure of the backfill.The research results can provide guidance for the application of MS and BFS as partial CSs in mine filling.
文摘A method, doping WC with La(NO 3) 3, of producing cemented carbide with rare earth was introduced. The effects of lanthanum on the mechanical properties and microstructure of WC 9(Co 75%Ni) cemented carbide were studied and a rock drilling experiment was carried out.The experimental results show that both transverse rupture strength (TRS) and hardness of WC 9(Co 75%Ni) rare earth cemented carbides can match that of WC 9Co cemented carbide, when La 2O 3 / (Co+Ni) ratio is 0.3%, the abnormal growth of WC grain in the cemented carbide can be restrained effectively, the homogeneity of grain size in microstructure and the wear resistance are improved, which can be matchable to that of WC 9Co cemented carbide for mining.
文摘We report on the application of Laser Induced Breakdown Spectroscopy(LIBS)technique to the study of Ca,P,Zn and Sr evolutions for adult caries-affected teeth using nanosecond laser pulses.The aim of this work is to better understand the behaviors of Zn and Sr as trace-elements in the caries eruption with respect to the behaviors of one of the main compounds of the hydroxyapatite crystal which is the calcium.The study was focused on the investigation of these elements’evolutions from three parts of the enamel surfaces of twenty two adult caries-affected teeth;the healthy part,the dental plaque part and the caries-affected part.The decrease rates of Zn,Sr and P was,also,compared to the Ca one.Comparison concerned normalized emission line intensities.For every species,normalization was done relatively to the emission line intensities of the healthy part.Results showed that abundances of these elements decrease similarly from the healthy parts to the affected-caries parts.The higher decrease rate was noticed for the calcium.The evolutions of Zn and Sr for the three parts of the teeth surfaces cannot inform about the substitution of the calcium by these trace-elements,however the comparison of their decrease rates to the calcium one can be considered as a valuable index of this substitution.
文摘One of the impediments in the genetic improvement of cotton fiber is the paucity of information about genes associated with fiber development.Availability of chromosome arm substitution line CS-
文摘A new kind of polyacrylamide derivate, hydroximic polyacrylamide (HPAM), was prepared from polyacrylamide (PAM) with hydroxylamine hydrochloride in KOH/alcohol solution. Based on colorimetric method in the measurement of C 7 9 alkyl hydroximic acid, the substitution degree of HPAM was determined by selecting octyl hydroximic acid as a primary standard substance. The effects of temperature, the amount of hydroxylamine and potassium hydroxide, and the reaction time on the reaction are discussed. HPAM with 5.78% substitution of degree was acquired by optimizing the reaction conditions. IR spectra revealed that tautomerism appears in the HPAM, and that HPAM exists in both the forms of hydroxamic type and hydroximic type, and the latter type can easily lead to the forming of intramolecular hydrogen bond.
基金Project(50071046) supported by the National Natural Science Foundation of China
文摘The simulations of Cr atom substitution character during the formation of L12 and DO22 phases in Ni-Cr-Al alloy were performed at 873 K based on microscopic phase-field model. It is found that the substitution of Cr is affected by Cr and Al contents and limits of occupation probabilities of Cr atom in L12 phase are present. The precipitate is single L12 phase when the component is less than the limit, Cr atoms substitute the Al sublattices in Ll2 phase, and both of atoms Al and Cr occupy the β-sites and complex phases Ni3（Al1-xCrx） are formed; Cr atoms enter Ni sites when Al and Cr contents exceed the limit, and substitute β-sites or both of α- and β-sites. The DO22 phase is formed at the boundary of Ll2 phase.
文摘The genetic base that cotton breeders commonly use to improve Upland cultivars is very narrow.The AD-genome species Gossypium barbadense,G.tomentosum,and G.mustelinum are part of
基金supported by the National Natural Science Foundation of China(6060309260975042)
文摘Being as unique nonlinear components of block ciphers,substitution boxes（S-boxes） directly affect the security of the cryptographic systems.It is important and difficult to design cryptographically strong S-boxes that simultaneously meet with multiple cryptographic criteria such as bijection,non-linearity,strict avalanche criterion（SAC）,bits independence criterion（BIC）,differential probability（DP） and linear probability（LP）.To deal with this problem,a chaotic S-box based on the artificial bee colony algorithm（CSABC） is designed.It uses the S-boxes generated by the six-dimensional compound hyperchaotic map as the initial individuals and employs ABC to improve their performance.In addition,it considers the nonlinearity and differential uniformity as the fitness functions.A series of experiments have been conducted to compare multiple cryptographic criteria of this algorithm with other algorithms.Simulation results show that the new algorithm has cryptographically strong S-box while meeting multiple cryptographic criteria.
文摘Nine 5 (β substituted stylryl) salicyladehyde derivatives were prepared by PTC Witting reactions in the paper . The stereochemistry of the Witting reactions and the substituted effect on the UV spectra of salicyladehyde derivaties have been reported . It was observed that the spectra undergo a red shift as the conjugative effect of substituted becomes stronger . A good linear relationship between the shift of UV of p substituted compounds and conjugation effect was obtained.It showed that the Hammett equation may be applied to the UV frequencies of the title compounds.
文摘In nature, iron cations in magnetite are usually isomorphically substituted by divalent (Co, Ni, Zn, Cu, Mn, etc.), trivalent (Al, V, Cr, etc.) and tetravalent (Ti) cations while maintaining the spinel structure. Some of the substituting cations, e.g. Cr3+, V3+ and Mn2+, improve the catalytic activity of magnetite in heterogeneous Fenton reaction through the enhancement of hydroxyl radical OH production and the pollutant adsorption.
基金Project(2013CB228600)supported by the National Basic Research Program of China
文摘The root mean square(RMS) difference of time-lapse seismic amplitudes is routinely used to identify the substituted fluid type in a reservoir during oil field production and recovery. By a time-lapse seismic method, we study the effects of fluid substitution in a physical model, which is an analogy of the three-dimensional inhomogeneous reservoir. For a weak inhomogeneous medium, gas/oil substitution results in positive anomalies in the reservoir layers, and negative anomalies below the bottom of the reservoir layers; while water/oil substitution causes only weak variations in the reservoir layers, but positive anomalies below the bottom of the reservoir layers. For the strong inhomogeneous medium, no matter what kind of fluid substitution(gas/oil or water/oil), there are significant anomalies in seismic amplitude difference attributes both in and below the reservoir layers. Therefore, for weak inhomogeneous media, such as tight sandstone or thin interbedded layers, the RMS amplitude difference attributes can be used to monitor fluid changes and predict the drilling direction; for inhomogeneous medium with karst carves or fractures, it is difficult to accurately determine the distribution of fluids with the RMS amplitude difference attributes.
文摘Five kinds of agricultural castoffs, such as sawdust and powder of coconut coir, were used as growing media to substitute the peat moss for potted Cyclamen percicum. It showed that most of the substitute media could fit for the growth of the root system without disturbing the spatial development of the root. The root activities of the plants in substitute media were all higher or not significantly lower than that in the contrast peat moss （PM）. The substitute media might not make adverse effects on the biosynthesis of chlorophyll of C. percicum leaves, and the nutrient components contained in the substitute media itself was none of the content of mineral elements in the leaves. The morphological indexes of C. percicum plants growing in the substitute media except in the powder of coconut coir （PCC） were all better than those in the contrast PM. The synthetically evaluation index of the plant showed that the sawdust, the powder of maize core, the powder of soybean stalk, the powder of peanut hull could take place the peat moss totally in C. percicum industrialization cultivation.
基金Project supported by the State Key Program of National Natural Science of China(No. 41130746)
文摘Detect the change of the Expression of oncoprotein on the Chinese hamster lung cells (V79 cells) which effect with two main district of China and four alternative chrysotile fiber to investigate the factors of lung cancer. V79 cells were exposed to the suspension of Chrysotile and its substitute with different powder content, the survival rate of cells was monitored by MTT. After 48 h, the location, distribution and expression of Survivin, Cap43, Bcl-2, p16 and p53 in V79 cell were examined by immunohistochemistry and compared. In the six kinds of powder, the inhibition of rockwool on the growth of cells was weakest, the inhibition of Chrysotile from Xinkang Sichuan and Southern Shanxi on the growth of cells was strongest. Chrysotile from Xinkang Sichuan, Chrysotile from Southern Shanxi, glass fiber, ceramic fiber, rockwool and wollastonite had a certain influence on the survival rate of V79 cells. As the concentration of powder increased the survival rate of cells decreased, which showed dose-effect relationship. The expression of Survivin, Cap43 and Bcl-2 was upregulated and the expression of P16 and P53 was downregulated in V79 cells, which was obviously in the powder suspension of Chrysotile from Southern Shanxi and Xinkang Sichuan and glass fiber. The expression was mainly in cytoplasm. The influence of different kind of powder on the cells differed in degree. Chrysotile and its substitute can induce the development of cancer by upregulating the expression of Survivin, Cap43 and Bcl-2 and downregulating the expression of p16 and p53.
文摘As it is known a complete coverage of cotton(Gossypium hirsutum L.) genome with hypoaneuploids is not still realized.Therefore the detection of new types of aneuploids especially in different cytogenetic collections is very useful.In Uzbekistan,long-term investigations towards development
