In order to design the relief system size of di-tert-butyl peroxide(DTBP) storage tanks,the runaway re-action of DTBP was simulated by accelerating rate calorimeter(ARC).The results indicated that under adiabatic cond...In order to design the relief system size of di-tert-butyl peroxide(DTBP) storage tanks,the runaway re-action of DTBP was simulated by accelerating rate calorimeter(ARC).The results indicated that under adiabatic conditions the initial exothermic temperature was 102.6 ℃,the maximum self-heating rate was 3.095×107 ℃·min-1,the maximum self-heating temperature was 375.9 ℃,and the pressure produced by unit mass was 4.512 MPa·g-1.Judged by ARC test,the emergency relief system for DTBP was a hybrid system.Based on Design Institute for Emergency Relief System(DIERS) method,the releasing mass flow rate W was determined by Leung methods,and the mass velocity G was calculated by two modified Omega methods.The two relief sizes calculated by monograph Omega method and arithmetic Omega method are close,with only 0.63% relative error.The monograph Omega method is more convenient to apply.展开更多
This paper describes a mathematical model developed to study the behavior of liquefied petroleum gas (LPG) tanks when subjected to jet fire. The model consists of a number of field and zone sub-models which are used t...This paper describes a mathematical model developed to study the behavior of liquefied petroleum gas (LPG) tanks when subjected to jet fire. The model consists of a number of field and zone sub-models which are used to simulate the various physical phenomena taking place during the tank engulfment period. The model can be used to predict the pressure and temperature of the LPG in the tank, the temperature of the wall of tank, and the time of tank explosion. The comparisons between the model predicted results and the test data show good agreement. The results show that the jet fire partially impinging on tank wall led to higher wall temperature and the time to failure was shorter than that in engulfing pool fire. And the exposure of the upper wall in the vapor zone to the fire is more dangerous than that of the LPG contacted wall.展开更多
A novel miniaturization of inductively coupled plasma (ICP) source based on printed circuit produced using micro-fabrication techniques is presented. The basic parameters of the novel ICP, including its radio freque...A novel miniaturization of inductively coupled plasma (ICP) source based on printed circuit produced using micro-fabrication techniques is presented. The basic parameters of the novel ICP, including its radio frequency, power loss, size, and argon consumption are less than 1% of that for the case of atmospheric pressure ICP source. For example, at 100 Pa of argon gas pressure, the present ICP source can be ignited by using the rf power less than 3.5 W. Potential applications of the ICP is discussed.展开更多
Titanium phosphonate adsorbent materials with hierarchically porous structure were fabricated using the hydrolysis of tetrabutyl titanate in different organophosphonic acids solutions. Based on the macroporous structu...Titanium phosphonate adsorbent materials with hierarchically porous structure were fabricated using the hydrolysis of tetrabutyl titanate in different organophosphonic acids solutions. Based on the macroporous structure of 100-2000 nm in size, a worm-hole like mesostructure was in the macropore walls, which was supported by the scanning electron microscopy(SEM), transmission electron microscopy(TEM), and N2 sorption analysis. Fourier transform infrared spectroscopy(FT-IR) data indicated the organic groups inside the solid materials framework. NH3 adsorption detection was performed using titanium phosphonate adsorbent materials and some significant results were obtained. The adsorption mechanism was also discussed in this study. Large adsorption amount(75.2 mg/g) was mainly attributed to the acid site via acid-base reactions and the physical adsorption site via Van der Waals forces. Resultant materials could effectively restrain the desorption of adsorbent NH3 back into air causing secondary pollution, so it could make a promising potential use in decontamination of gas pollutants in the future.展开更多
Recursive algorithms are very useful for computing M-estimators of regression coefficients and scatter parameters. In this article, it is shown that for a nondecreasing ul (t), under some mild conditions the recursi...Recursive algorithms are very useful for computing M-estimators of regression coefficients and scatter parameters. In this article, it is shown that for a nondecreasing ul (t), under some mild conditions the recursive M-estimators of regression coefficients and scatter parameters are strongly consistent and the recursive M-estimator of the regression coefficients is also asymptotically normal distributed. Furthermore, optimal recursive M-estimators, asymptotic efficiencies of recursive M-estimators and asymptotic relative efficiencies between recursive M-estimators of regression coefficients are studied.展开更多
Effects of hypoxia on learning-memory function and swimming capability of rat were studied and the ergonomics under hypoxic condition was also evaluated from the biological point of view.Three modes of hypoxia were de...Effects of hypoxia on learning-memory function and swimming capability of rat were studied and the ergonomics under hypoxic condition was also evaluated from the biological point of view.Three modes of hypoxia were designed and plots of oxygen concentration versus time for each group in hypoxic environment were produced.Results showed that the effects of hypoxia on learning-memory function and swimming capability were related with the time and strength of hypoxia.It had nothing to do with the individual difference of rat models.10% O2 long-term intermittent anamorphosis hypoxia could improve the swimming capability of rat model significantly.Stimulating with proper level of hypoxia,carbon dioxide could improve ergonomics in airtight hypoxia environment.Under hypoxia condition,from the ergonomic point of view,6% O2 is the important threshold and might belong in critical region.展开更多
This work presents an approach to build a high-performance, low-viscous and replaceable separation matrix, semi-crosslinked polyacrylamide (semi-CPA) capillary gel electrophoresis. Non- denatured basic proteins, suc...This work presents an approach to build a high-performance, low-viscous and replaceable separation matrix, semi-crosslinked polyacrylamide (semi-CPA) capillary gel electrophoresis. Non- denatured basic proteins, such as lysozyme, cytochrome C, ribonuclease A and trypsin were separa- ted. The impacts of monomer and cross-linker concentrations on protein separation were studied, and the ability of dynamic capillary inner wall coating was demonstrated. The UV absorption interfer- ence by semi-CPA gel matrix was successfully overcome by a partial filling technique, which results in sensitivity 20 times higher than other protein separation method. The excellent separation ability, reproducibility and dynamic coating ability made semi-CPA an ideal separation media in both capillar- y electrophoresis and microfluidic chip separation scheme.展开更多
The fire causes water pollution, air pollution and toxic gas pollution to our surrounding environment, and it seriously affects our living environment. People's awareness of environmental protection is increasing ...The fire causes water pollution, air pollution and toxic gas pollution to our surrounding environment, and it seriously affects our living environment. People's awareness of environmental protection is increasing year by year, and environmental pollution caused by the fire is also being controlled. This article briefly introduces the fire accident's impact on the environment, the systematic analysis of the fire accident in the source of pollution and its harm. Combined with the existing way of fire fighting and rescue fire accident, the pollution control method is proposed.展开更多
Based on the power spectra of gravity anomalies in Tarim Basin, the anomalies can be decomposed to the following three components: a sub-anomaly formed mainly by the basin crystallized basement, a sub-anomaly formed m...Based on the power spectra of gravity anomalies in Tarim Basin, the anomalies can be decomposed to the following three components: a sub-anomaly formed mainly by the basin crystallized basement, a sub-anomaly formed mainly by deep sedimentary layers, and that by shallow sedimentary layers. A special wavelet transform analysis scheme and a density inversion method are designed and applied to the decomposition and inversion of gravity sub-anomalies, which are correlated with regional geology and drilling data. The results indicate that the deep and the shallow sub-anomalies show some relations with ancient fluid active zones. The negative density disturbances inversed from the shallow sub-anomaly are mainly caused by Mesozoic fluid active zones, whereas the negative density disturbances form the deep sub-anomalies are mainly correlated with Paleozoic fluid active zones. As the ancient fluid movement was good for formation of oil/gas fields, the multi-scale inversion methods for locating the ancient fluid movement zones seem to be helpful and valuable to oil/gas exploration.展开更多
Objective: To investigate the effects of Xuebijing Injection(血必净注射液, XBJ) on survival rate and pulmonary vasopermeability in a rat model of severe scald injury. Methods: Rats were divided into two experiment...Objective: To investigate the effects of Xuebijing Injection(血必净注射液, XBJ) on survival rate and pulmonary vasopermeability in a rat model of severe scald injury. Methods: Rats were divided into two experiments: experiment 1 was monitored for 12 h post-injury for survival analysis after severe burns; in experiment 2, rats were killed for determination of pulmonary vascular permeability and pro-inflammatory mediators. In both experiments, rats were subject to third-degree 50% total body surface area(TBSA) burns or sham injury followed by XBJ or normal saline(NS) treatment. In addition, rat pulmonary microvascular endothelium cells(PMECs) were pretreated with either XBJ or phosphate buffer saline(PBS), and then subjected to sham serum or scald serum stimulation for 2 or 6 h, followed by transwell examination for the permeability of PMECs. Meanwhile, pro-inflammatory mediators in PMECs culture supernatant were also investigated. Results: The average survival time in the scald+XBJ group was 582.1±21.2 min, which was significantly longer than that in the scald + NS group(345.8±25.4 min, P〈0.01). Plasma levels of tumor necrosis factor-alpha(TNF-α), E-selectin, interleukin-6(IL-6), vascular permeability and water content of lung tissues were significantly increased in animals after severe burns(P〈0.01). However, administration of XBJ significantly decreased these levels in plasma and lung tissue. In in vitro cell experiments, XBJ markedly attenuated permeability in PMECs monolayer and reduced the levels of TNF-α, IL-6 and soluble E-selectin after stimulation with scald serum(P〈0.01). Conclusions: XBJ increases early survival rate by alleviating pulmonary vasopermeability and inhibiting pro-inflammatory mediators in rats subjected to lethal scald injury. XBJ may be a potent drug in treatment of severe burns.展开更多
Polystyrene (PS)/triphenyl phosphate (TPP) composites were prepared by both suspension polymerization and melt extrusion, and a comparative study of the flame retardance and mechanical properties was carried out. ...Polystyrene (PS)/triphenyl phosphate (TPP) composites were prepared by both suspension polymerization and melt extrusion, and a comparative study of the flame retardance and mechanical properties was carried out. The results showed that suspension polymerization was a better technique than melt extrusion for obtaining good dispersity of the PS/TPP composite. The TPP nanoparticles, which were approximately 50 nm in size, were homogenously and uniformly dispersed in the PS matrix by suspension polymerization in one-step. However, the PS/TPP composite was partially agglomerated, exhibiting irregularly shaped micron-scale particles as a result of melt extrusion. In contrast to the melt extrusion, the limited oxygen index (LOI) of the PS/TPP nanocomposite by suspension polymerization increased to 22.6% from 21.8%, and time to ignition (TTI) increased by 12.3%, the peak heat release rate (PHRR) decreased by 8.5%, and the total heat release (THR) decreased by 11.0%. The mechanical properties of the PS/TPP nanocomposite by suspension polymerization also increased. The tensile strength, elongation at break, and flexural strength increased by 36.4%, 8.5%, and 108%, respectively.展开更多
A series of cholesterol-appended quinacridone (QA) derivatives 1a-1d have been synthesized,in which 1b and 1c could form stable organogels in a wide range of organic solvents upon ultrasound irradiation.Field emission...A series of cholesterol-appended quinacridone (QA) derivatives 1a-1d have been synthesized,in which 1b and 1c could form stable organogels in a wide range of organic solvents upon ultrasound irradiation.Field emission scanning electronic microscope (FESEM) and transmission electron microscopy (TEM) of xerogels or precipitates indicated that 1b and 1c formed 1D fibrous nanostructure,while 1a assembled into 3D flower-like microstructures.The ultrasound-induced organogel process was characterized by kinetic UV-vis and photoluminescence spectroscopic methods suggesting the formation of ?-? aggregates in the gel state.Experimental results demonstrated that the ultrasound could promote molecules to contact frequently in the solution and induce semistable initial aggregates,which propagate to form nano/micro superstructures.The aggregation model was optimized by semiempirical AM1 calculation suggesting the hierarchical self-assembly process.In addition,the formed xerogel film exhibited mechanochromic property,and the phase transition process was accompanied by the fluorescence changes between yellowish green and orange.展开更多
A new and convenient method is used to study the existence of periodic solutions to neutral functional differential equations with infinite delay. A new criterion for the existence of periodic solutions is obtained in...A new and convenient method is used to study the existence of periodic solutions to neutral functional differential equations with infinite delay. A new criterion for the existence of periodic solutions is obtained in this paper.展开更多
This paper reports on the synthesis, characterization and electrochemical performance of LiV3O8 nanorods which were prepared through a very facile hydrothermal route. The diameters of the LiV3O8 nanorods are about 150...This paper reports on the synthesis, characterization and electrochemical performance of LiV3O8 nanorods which were prepared through a very facile hydrothermal route. The diameters of the LiV3O8 nanorods are about 150 nm. The morphology of LiV3O8 can be controlled by adjusting the reaction conditions such as the reaction time and temperature. Electrochemical measurements reveal that the as-prepared LiV3O8 nanorods display high initial dis- charge capacities (292.5 mAohg-1 ) and excellent cyclability. This result indicates that the nanorods are a promising cathode candidate material for lithium batteries.展开更多
In this paper, we investigate the existence of incomplete group divisible designs (IGDDs) with block size four, group-type (g, h) u and general index λ. The necessary conditions for the existence of such a design...In this paper, we investigate the existence of incomplete group divisible designs (IGDDs) with block size four, group-type (g, h) u and general index λ. The necessary conditions for the existence of such a design are that u ≥ 4, g ≥ 3h, λg(u 1) ≡ 0 (mod 3), λ(g h)(u 1) ≡ 0 (mod 3), and λu(u 1)(g 2 h 2 ) ≡ 0 (mod 12). These necessary conditions are shown to be sufficient for all λ≥ 2. The known existence result for λ = 1 is also improved.展开更多
The existence of periodic solution to nonlinear integral equations with infinite delay is studied in this paper. We prove that the g- uniform bounded and g- uniform ultimate bounded solutions implies the existence of ...The existence of periodic solution to nonlinear integral equations with infinite delay is studied in this paper. We prove that the g- uniform bounded and g- uniform ultimate bounded solutions implies the existence of periodic solutions using Schauder-Tychonov’s fixed point theorem in the phase space (Cg,|·|g).展开更多
In this paper, the existence of periodic solution to nonlinear integro-differential equations with infinite delay is studied in the phase space (Cg,|·|g). We prove that the g-uniformly ultimately bounded solution...In this paper, the existence of periodic solution to nonlinear integro-differential equations with infinite delay is studied in the phase space (Cg,|·|g). We prove that the g-uniformly ultimately bounded solutions implies the existence of periodic solutions using Horn’s fixed point theorem. Some known results are generalized, including the famous Yoshizawa’s theorem.展开更多
文摘In order to design the relief system size of di-tert-butyl peroxide(DTBP) storage tanks,the runaway re-action of DTBP was simulated by accelerating rate calorimeter(ARC).The results indicated that under adiabatic conditions the initial exothermic temperature was 102.6 ℃,the maximum self-heating rate was 3.095×107 ℃·min-1,the maximum self-heating temperature was 375.9 ℃,and the pressure produced by unit mass was 4.512 MPa·g-1.Judged by ARC test,the emergency relief system for DTBP was a hybrid system.Based on Design Institute for Emergency Relief System(DIERS) method,the releasing mass flow rate W was determined by Leung methods,and the mass velocity G was calculated by two modified Omega methods.The two relief sizes calculated by monograph Omega method and arithmetic Omega method are close,with only 0.63% relative error.The monograph Omega method is more convenient to apply.
文摘This paper describes a mathematical model developed to study the behavior of liquefied petroleum gas (LPG) tanks when subjected to jet fire. The model consists of a number of field and zone sub-models which are used to simulate the various physical phenomena taking place during the tank engulfment period. The model can be used to predict the pressure and temperature of the LPG in the tank, the temperature of the wall of tank, and the time of tank explosion. The comparisons between the model predicted results and the test data show good agreement. The results show that the jet fire partially impinging on tank wall led to higher wall temperature and the time to failure was shorter than that in engulfing pool fire. And the exposure of the upper wall in the vapor zone to the fire is more dangerous than that of the LPG contacted wall.
文摘A novel miniaturization of inductively coupled plasma (ICP) source based on printed circuit produced using micro-fabrication techniques is presented. The basic parameters of the novel ICP, including its radio frequency, power loss, size, and argon consumption are less than 1% of that for the case of atmospheric pressure ICP source. For example, at 100 Pa of argon gas pressure, the present ICP source can be ignited by using the rf power less than 3.5 W. Potential applications of the ICP is discussed.
基金Funded by the National Science&Technology Pillar Program during the Twelfth Five-year Plan Period(2011BAK03B07)the Specialized Research Fund for the Technology Research Program of Ministry of Public Security(2014JSYJA024)the Specialized Research Fund for the Applications Innovation Program of Ministry of Public Security(2011YYCXWJXY131)
文摘Titanium phosphonate adsorbent materials with hierarchically porous structure were fabricated using the hydrolysis of tetrabutyl titanate in different organophosphonic acids solutions. Based on the macroporous structure of 100-2000 nm in size, a worm-hole like mesostructure was in the macropore walls, which was supported by the scanning electron microscopy(SEM), transmission electron microscopy(TEM), and N2 sorption analysis. Fourier transform infrared spectroscopy(FT-IR) data indicated the organic groups inside the solid materials framework. NH3 adsorption detection was performed using titanium phosphonate adsorbent materials and some significant results were obtained. The adsorption mechanism was also discussed in this study. Large adsorption amount(75.2 mg/g) was mainly attributed to the acid site via acid-base reactions and the physical adsorption site via Van der Waals forces. Resultant materials could effectively restrain the desorption of adsorbent NH3 back into air causing secondary pollution, so it could make a promising potential use in decontamination of gas pollutants in the future.
基金supported by the Natural Sciences and Engineering Research Council of Canadathe National Natural Science Foundation of China+2 种基金the Doctorial Fund of Education Ministry of Chinasupported by the Natural Sciences and Engineering Research Council of Canadasupported by the National Natural Science Foundation of China
文摘Recursive algorithms are very useful for computing M-estimators of regression coefficients and scatter parameters. In this article, it is shown that for a nondecreasing ul (t), under some mild conditions the recursive M-estimators of regression coefficients and scatter parameters are strongly consistent and the recursive M-estimator of the regression coefficients is also asymptotically normal distributed. Furthermore, optimal recursive M-estimators, asymptotic efficiencies of recursive M-estimators and asymptotic relative efficiencies between recursive M-estimators of regression coefficients are studied.
基金Sponsored by the National Natural Science Foundation of China(20705005)Commission of Science Technology and Industry for National Defence(A2220060042)
文摘Effects of hypoxia on learning-memory function and swimming capability of rat were studied and the ergonomics under hypoxic condition was also evaluated from the biological point of view.Three modes of hypoxia were designed and plots of oxygen concentration versus time for each group in hypoxic environment were produced.Results showed that the effects of hypoxia on learning-memory function and swimming capability were related with the time and strength of hypoxia.It had nothing to do with the individual difference of rat models.10% O2 long-term intermittent anamorphosis hypoxia could improve the swimming capability of rat model significantly.Stimulating with proper level of hypoxia,carbon dioxide could improve ergonomics in airtight hypoxia environment.Under hypoxia condition,from the ergonomic point of view,6% O2 is the important threshold and might belong in critical region.
基金Supported by the Key Project in the National Science & Tech- nology Pillar Program During the Eleventh Five-Year Plan Pe- riod (2009BAK59B02)
文摘This work presents an approach to build a high-performance, low-viscous and replaceable separation matrix, semi-crosslinked polyacrylamide (semi-CPA) capillary gel electrophoresis. Non- denatured basic proteins, such as lysozyme, cytochrome C, ribonuclease A and trypsin were separa- ted. The impacts of monomer and cross-linker concentrations on protein separation were studied, and the ability of dynamic capillary inner wall coating was demonstrated. The UV absorption interfer- ence by semi-CPA gel matrix was successfully overcome by a partial filling technique, which results in sensitivity 20 times higher than other protein separation method. The excellent separation ability, reproducibility and dynamic coating ability made semi-CPA an ideal separation media in both capillar- y electrophoresis and microfluidic chip separation scheme.
文摘The fire causes water pollution, air pollution and toxic gas pollution to our surrounding environment, and it seriously affects our living environment. People's awareness of environmental protection is increasing year by year, and environmental pollution caused by the fire is also being controlled. This article briefly introduces the fire accident's impact on the environment, the systematic analysis of the fire accident in the source of pollution and its harm. Combined with the existing way of fire fighting and rescue fire accident, the pollution control method is proposed.
文摘Based on the power spectra of gravity anomalies in Tarim Basin, the anomalies can be decomposed to the following three components: a sub-anomaly formed mainly by the basin crystallized basement, a sub-anomaly formed mainly by deep sedimentary layers, and that by shallow sedimentary layers. A special wavelet transform analysis scheme and a density inversion method are designed and applied to the decomposition and inversion of gravity sub-anomalies, which are correlated with regional geology and drilling data. The results indicate that the deep and the shallow sub-anomalies show some relations with ancient fluid active zones. The negative density disturbances inversed from the shallow sub-anomaly are mainly caused by Mesozoic fluid active zones, whereas the negative density disturbances form the deep sub-anomalies are mainly correlated with Paleozoic fluid active zones. As the ancient fluid movement was good for formation of oil/gas fields, the multi-scale inversion methods for locating the ancient fluid movement zones seem to be helpful and valuable to oil/gas exploration.
基金Supported by the National Natural Science Foundation of China(No.81471872)
文摘Objective: To investigate the effects of Xuebijing Injection(血必净注射液, XBJ) on survival rate and pulmonary vasopermeability in a rat model of severe scald injury. Methods: Rats were divided into two experiments: experiment 1 was monitored for 12 h post-injury for survival analysis after severe burns; in experiment 2, rats were killed for determination of pulmonary vascular permeability and pro-inflammatory mediators. In both experiments, rats were subject to third-degree 50% total body surface area(TBSA) burns or sham injury followed by XBJ or normal saline(NS) treatment. In addition, rat pulmonary microvascular endothelium cells(PMECs) were pretreated with either XBJ or phosphate buffer saline(PBS), and then subjected to sham serum or scald serum stimulation for 2 or 6 h, followed by transwell examination for the permeability of PMECs. Meanwhile, pro-inflammatory mediators in PMECs culture supernatant were also investigated. Results: The average survival time in the scald+XBJ group was 582.1±21.2 min, which was significantly longer than that in the scald + NS group(345.8±25.4 min, P〈0.01). Plasma levels of tumor necrosis factor-alpha(TNF-α), E-selectin, interleukin-6(IL-6), vascular permeability and water content of lung tissues were significantly increased in animals after severe burns(P〈0.01). However, administration of XBJ significantly decreased these levels in plasma and lung tissue. In in vitro cell experiments, XBJ markedly attenuated permeability in PMECs monolayer and reduced the levels of TNF-α, IL-6 and soluble E-selectin after stimulation with scald serum(P〈0.01). Conclusions: XBJ increases early survival rate by alleviating pulmonary vasopermeability and inhibiting pro-inflammatory mediators in rats subjected to lethal scald injury. XBJ may be a potent drug in treatment of severe burns.
文摘Polystyrene (PS)/triphenyl phosphate (TPP) composites were prepared by both suspension polymerization and melt extrusion, and a comparative study of the flame retardance and mechanical properties was carried out. The results showed that suspension polymerization was a better technique than melt extrusion for obtaining good dispersity of the PS/TPP composite. The TPP nanoparticles, which were approximately 50 nm in size, were homogenously and uniformly dispersed in the PS matrix by suspension polymerization in one-step. However, the PS/TPP composite was partially agglomerated, exhibiting irregularly shaped micron-scale particles as a result of melt extrusion. In contrast to the melt extrusion, the limited oxygen index (LOI) of the PS/TPP nanocomposite by suspension polymerization increased to 22.6% from 21.8%, and time to ignition (TTI) increased by 12.3%, the peak heat release rate (PHRR) decreased by 8.5%, and the total heat release (THR) decreased by 11.0%. The mechanical properties of the PS/TPP nanocomposite by suspension polymerization also increased. The tensile strength, elongation at break, and flexural strength increased by 36.4%, 8.5%, and 108%, respectively.
基金supported by the National Natural Science Foundation of China (50773027 and 50733002)the National Basic Research Development Program (2009CB939700)111 Project (B06009)
文摘A series of cholesterol-appended quinacridone (QA) derivatives 1a-1d have been synthesized,in which 1b and 1c could form stable organogels in a wide range of organic solvents upon ultrasound irradiation.Field emission scanning electronic microscope (FESEM) and transmission electron microscopy (TEM) of xerogels or precipitates indicated that 1b and 1c formed 1D fibrous nanostructure,while 1a assembled into 3D flower-like microstructures.The ultrasound-induced organogel process was characterized by kinetic UV-vis and photoluminescence spectroscopic methods suggesting the formation of ?-? aggregates in the gel state.Experimental results demonstrated that the ultrasound could promote molecules to contact frequently in the solution and induce semistable initial aggregates,which propagate to form nano/micro superstructures.The aggregation model was optimized by semiempirical AM1 calculation suggesting the hierarchical self-assembly process.In addition,the formed xerogel film exhibited mechanochromic property,and the phase transition process was accompanied by the fluorescence changes between yellowish green and orange.
基金supported by the Foundation of Educational Department of Hebei Province(Z2011333)
文摘A new and convenient method is used to study the existence of periodic solutions to neutral functional differential equations with infinite delay. A new criterion for the existence of periodic solutions is obtained in this paper.
文摘This paper reports on the synthesis, characterization and electrochemical performance of LiV3O8 nanorods which were prepared through a very facile hydrothermal route. The diameters of the LiV3O8 nanorods are about 150 nm. The morphology of LiV3O8 can be controlled by adjusting the reaction conditions such as the reaction time and temperature. Electrochemical measurements reveal that the as-prepared LiV3O8 nanorods display high initial dis- charge capacities (292.5 mAohg-1 ) and excellent cyclability. This result indicates that the nanorods are a promising cathode candidate material for lithium batteries.
基金Supported by the National Natural Science Foundation of China (No. 10571043, 10771051, 11001182, 10901051)
文摘In this paper, we investigate the existence of incomplete group divisible designs (IGDDs) with block size four, group-type (g, h) u and general index λ. The necessary conditions for the existence of such a design are that u ≥ 4, g ≥ 3h, λg(u 1) ≡ 0 (mod 3), λ(g h)(u 1) ≡ 0 (mod 3), and λu(u 1)(g 2 h 2 ) ≡ 0 (mod 12). These necessary conditions are shown to be sufficient for all λ≥ 2. The known existence result for λ = 1 is also improved.
基金supported by the National Natural Sciences Foundations of China (10771107)
文摘The existence of periodic solution to nonlinear integral equations with infinite delay is studied in this paper. We prove that the g- uniform bounded and g- uniform ultimate bounded solutions implies the existence of periodic solutions using Schauder-Tychonov’s fixed point theorem in the phase space (Cg,|·|g).
基金supported by National Natural Sciences Foundations of China (10771107)
文摘In this paper, the existence of periodic solution to nonlinear integro-differential equations with infinite delay is studied in the phase space (Cg,|·|g). We prove that the g-uniformly ultimately bounded solutions implies the existence of periodic solutions using Horn’s fixed point theorem. Some known results are generalized, including the famous Yoshizawa’s theorem.