A significant promotion effect of low-molecular hydroxyl compounds(LMHCs) was found in the nano-photoelectrocatalytic(NPEC) degradation of fulvic acid(FA),which is a typical kind of humic acid existing widely in natur...A significant promotion effect of low-molecular hydroxyl compounds(LMHCs) was found in the nano-photoelectrocatalytic(NPEC) degradation of fulvic acid(FA),which is a typical kind of humic acid existing widely in natural water bodies,and its influence mechanism was proposed.A TiO_2 nanotube arrays(TNAs) material is served as the photoanode.Methanol,ethanediol,and glycerol were chosen as the representative of LMHCs in this study.The adsorption performance of organics on the surface of TNAs was investigated by using the instantaneous photocurrent value.The adsorption constants of FA,methanol,ethanediol,and glycerol were 43.44,19.32,7.00,and 1.30,respectively,which indicates that FA has the strongest adsorption property.The degradation performance of these organics and their mixture were observed in a thin-layer reactor.It shows that FA could hardly achieve exhausted mineralization alone,while LMHCs could be easily oxidized completely in the same condition.The degradation degree of FA,which is added LMHCs,improves significantly and the best promotion effect is achieved by glycerol.The promotion effect of LMHCs in the degradation of FA could be contributed to the formation of a tremendous amount of hydroxyl radicals in the NPEC process.The hydroxyl radicals could facilitate the complete degradation of both FA and its intermediate products.Among the chosen LMHCs,glycerol molecule which has three hydroxyls could generate the most hydroxyl radicals and contribute the best effective promotion.This work provides a new way to promote the NPEC degradation of FA and a direction to remove humus from polluted water.展开更多
The 96 h acute toxic effects of nano-CuO (N-CuO), micro-CuO (M-CuO) and 2+ on Chlorella sp. were investigated in this paper. The results showed that toxicities decreased in an order of Cu2+>N-CuO>M-CuO. The 96 h...The 96 h acute toxic effects of nano-CuO (N-CuO), micro-CuO (M-CuO) and 2+ on Chlorella sp. were investigated in this paper. The results showed that toxicities decreased in an order of Cu2+>N-CuO>M-CuO. The 96 h EC50 of Cu2+ on Chlorella sp. was 1.06 mg /L, and of N-CuO it was 74.61 mg /L, while no pronounced toxicity was observed when the concentration of M-CuO was lower than 160 mg/L. Further experiments were carried out in order to study the toxicity mechanism of nano-CuO on Chlorella sp.. The results of Cu2+ release from N-CuO showed less than 0.2 mg/L Cu2+ were released, so the release of Cu2+ was not responsible for the toxicity. Further experiments showed N-CuO inhibited formation of Chlorophyll A. Content of Chlorophyll A in the control group was 4.75 mg/108 cells, while it declined to 2.89 mg/108 cells for 160 mg/L N-CuO after 96 h, which indicated that N-CuO could inhibit photosynthesis of Chlorella sp.. Moreover, N-CuO condensed with algal cells. It affected the activity of SOD and POD, indicating that N-CuO could cause oxidant stress to Chlorella sp.. These may be the toxicity mechanism.展开更多
This paper deals with the study of the temperature effect on the nonlinear vibration behavior of nanoplate-based nano electromechanical systems（NEMS） subjected to hydrostatic and electrostatic actuations. Using Erin...This paper deals with the study of the temperature effect on the nonlinear vibration behavior of nanoplate-based nano electromechanical systems（NEMS） subjected to hydrostatic and electrostatic actuations. Using Eringen＇s nonlocal elasticity and Gurtin–Murdoch theory, the nonlocal plate model is derived through Hamilton＇s principle. The governing equation which is extremely nonlinear due to the geometrical nonlinearity and electrostatic attraction forces is solved numerically using the differential quadrature method（DQM）. The accuracy of the present method is veriied by comparing the obtained results with the experimental data and those in the literature and very good agreement is obtained. Finally a comprehensive study is carried out to determine the inluence of temperature on the nonlinear vibration characteristics of NEMS made of two different materials including aluminum（Al）and silicon（Si） and some conclusions are drawn.展开更多
Cell surface of aquatic organisms constitutes a primary site for the interaction and a barrier for the nano-TiO2 biological effects.In the present study,the biological effects of nano-TiO2 on a unicellular green algae...Cell surface of aquatic organisms constitutes a primary site for the interaction and a barrier for the nano-TiO2 biological effects.In the present study,the biological effects of nano-TiO2 on a unicellular green algae Chlamydomonas reinhardtii were studied by observing the changes of the cell surface morphology and functional groups under UV or natural light.By SEM,the cell surface morphology of C.reinhardtii was changed under UV light,nano-TiO2 with UV light or natural light,which indicated that photocatalysis damaged cell surface.It was also observed that cell surface was surrounded by TiO2 nanoparticles.The ATR-FTIR spectra showed that the peaks of functional groups such as C-N,-C=O,-C-O-C and P=O,which were the important components of cell wall and membrane,were all depressed by the photocatalysis of nano-TiO2 under UV light or natural light.The photocatalysis of nano-TiO2 promoted peroxidation of functional groups on the surface of C.reinhardtii cells,which led to the damages of cell wall and membrane.展开更多
The inhibition effect of tert-butyl alcohol(TBA), identified as the·OH radical inhibitor, on the TiO_2 nano assays(TNA) photoelectrocatalytic oxidation of different organics such as glucose and phthalate was repo...The inhibition effect of tert-butyl alcohol(TBA), identified as the·OH radical inhibitor, on the TiO_2 nano assays(TNA) photoelectrocatalytic oxidation of different organics such as glucose and phthalate was reported. The adsorption performance of these organics on the TNA photoelectrode was investigated by using the instantaneous photocurrent value, and the degradation property was examined by using the exhausted reaction. The results showed that glucose exhibited the poor adsorption and easy degradation performance, phthalate showed the strong adsorption and harddegradation, but TBA showed the weak adsorption and was the most difficult to be degraded. The degradation of both glucose and phthalate could be inhibited evidently by TBA. But the effect on glucose was more obvious. The different inhibition effects of TBA on different organics could be attributed to the differences in the adsorption and the degradation property. For instance, phthalate of the strong adsorption property could avoid from the capture of·OH radicals by TBA in TNA photoelectrocatalytic process.展开更多
The model of a screw dislocation near a semi-infinite wedge crack tip inside a nano-circular inclusion is proposed to investigate the shielding effect of nano inclusions acting on cracks. Utilizing the complex functio...The model of a screw dislocation near a semi-infinite wedge crack tip inside a nano-circular inclusion is proposed to investigate the shielding effect of nano inclusions acting on cracks. Utilizing the complex function method, the closed-form solutions of the stress fields in the matrix and the inclusion region are derived. The stress intensity factor, the image force, as well as the critical loads for dislocation emission are discussed in detail. The results show that the nano inclusion not only enhances the shielding effect exerted by the dislocation, but also provides a shielding effect itself. Moreover, dislocations may be trapped in the nano inclusion even if the matrix is softer than the inclusion. This helps the dislocation shield crack, and reduces the dislocation density within the matrix.展开更多
The coating and deposition process with excellent anti wear and suitable for industrial application were developed, and the optimum bath composition and process were obtained by studying the influence of the bath comp...The coating and deposition process with excellent anti wear and suitable for industrial application were developed, and the optimum bath composition and process were obtained by studying the influence of the bath composition, temperature and pH value on the deposition rate and the plating solution stability. Moreover, the tribological properties of nano-Cu lubricating additives and electroless deposited Ni-W-P coating as well as their synergistic effect are researched using ring-block abrasion testing machine and energy dispersive spectrometer. Research results show that Ni-W-P alloy coating and nano-Cu lubricating additive have excellent synergistic effect, e g, the wear resistance of Ni-W-P alloy coating （with heat treatment and the oil with nano-Cu additives） has increased hundreds times than 45 steel as the metal substrate with the basic oil, and zero wear is achieved, which breaks through the bottleneck of previous separate research of the above-mentioned two aspects.展开更多
The nano-titanium dioxide (nano-TiO_2) sensing membrane,fabricated by sol-gel technology,was used as the pH-sensing layer of the extended gate field effect transistor (EGFET) device.The objective of this research is t...The nano-titanium dioxide (nano-TiO_2) sensing membrane,fabricated by sol-gel technology,was used as the pH-sensing layer of the extended gate field effect transistor (EGFET) device.The objective of this research is the preparation of titanium dioxide materials by sol-gel method using Ti(OBu)_4 as the precursor.In this study,we fabricated a nano-titanium dioxide sensing layer on the ITO glass by dip coating.In order to examine the sensitivity of the nano-TiO_2 films applied to the EGFET devices,we adopted the ITO glass as substrate,and measured theⅠ_(DS)-Ⅴ_G curves of the nano-titanium dioxide separative structure EGFET device in the pH buffer solutions that have different pH values by the Keithley 236 Instrument.By the experimental results,we can obtain the pH sensitivities of the EGFET with nano-TiO_2 sensing membrane prepared by sol-gel method,which is 59.86mV/pH from pH 1 to pH 9.展开更多
The major solving ways for the material wear are surface modification and lubrication. Currently, the researches at home and abroad are all limited to the single study of either nano-lubricating oil additive or electr...The major solving ways for the material wear are surface modification and lubrication. Currently, the researches at home and abroad are all limited to the single study of either nano-lubricating oil additive or electroless deposited coating. The surface coating has high hardness and high wear resistance, however, the friction reduction performance of the coating with high hardness is not good, the thickness of the coating is limited, and the coating can not regenerate after wearing. The nano-lubricating additives have good tribological performance and self-repair function, but under heavy load, the self-repair rate to the worn surface with the nano-additives is smaller than the wearing rate of the friction pair. To solve the above problems, the Ni-W-P alloy coating and deposition process with excellent anti-wear, and suitable for industrial application were developed, the optimum bath composition and process can be obtained by studying the influence of the bath composition, temperature and PH value to the deposition rate and the plating solution stability. The tribological properties as well as anti-wear and friction reduction mechanism of wear self-repair nano-ceramic lubricating additives are also studied. The ring-block abrasion testing machine and energy dispersive spectrometer are used to explore the internal relation between the coating and the nano-lubricating oil additives, and the tribology mechanism, to seek the synergetic effect between the two. The test results show that the wear resistance of Ni-W-P alloy coating （with heat treatment and in oil with nano-ceramic additives） has increased hundreds times than 45 steel as the metal substrate in basic oil, the friction reduction performance is improved. This research breaks through the bottleneck of previous separate research of the above-mentioned two methods, and explores the combination use of the two methods in industrial field.展开更多
[Objectives] This study was carried out to explore the selenium-enriching effect of different crops, and provide certain references for production of selenium-enriched agricultural products. [Methods] Four kinds of cr...[Objectives] This study was carried out to explore the selenium-enriching effect of different crops, and provide certain references for production of selenium-enriched agricultural products. [Methods] Four kinds of crops （tomato, leaf mustard, peanut, and carrot） were exogenous selenium fertilizer treated, to explore the selenium-enriching effects on these crops. [Results] Exogenous application of microbial nano-selenium can significantly increase the selenium content of the crops, of which the effects on big tomato （Weiyanuo） were the best. After spraying, the selenium content increased by 1.39 times, and at the same time the sugar content of tomato was also increased. [Conclusions] This study is expected to provide references for increase of the selenium content of agricultural products.展开更多
Using alkalescent ammonium(AAC)as precipitatnt, the diameter of nano La_2O_3 powder with diameter in 80 nm and less was prepared by the method of homogeneous precipitation, and reactant concentration, temperature and ...Using alkalescent ammonium(AAC)as precipitatnt, the diameter of nano La_2O_3 powder with diameter in 80 nm and less was prepared by the method of homogeneous precipitation, and reactant concentration, temperature and pH were studied and confirmed. The best precipitated concentration is from 0.2 to 0.5 mol·L^(-1), and the diameter of compounded powder turns small as the temperature gradually becomes high, and the pH from 6 to 8 is the best and the concentration of precipitant does not affect the diameter of compounded powder significantly. Meanwhile, most experiments lasting for fifty days in the greenhouse, and the results are 0.2 g·kg^(-1) nano La_2O_3 powder is enorgh for increasing biomass by 133% compared with that of the CK.展开更多
The governing differential equation of micro/nanbeams with atom/molecule adsorption is derived in the presence of surface effects using the nonlocal elasticity. The effects of the nonlocal parameter, the adsorption de...The governing differential equation of micro/nanbeams with atom/molecule adsorption is derived in the presence of surface effects using the nonlocal elasticity. The effects of the nonlocal parameter, the adsorption density, and the surface parameter on the resonant frequency of the micro/nanobeams are investigated. It is found that, in ad- dition to the nonlocal parameter and the surface parameter, the bending rigidity and the adsorption-induced mass exhibit different behaviors with the increase in the adsorption density depending on the adatom category and the substrate material.展开更多
A basically topological interpretation of the Casimir effect is given as a natural intrinsic property of the geometrical topological structure of the quantum-Cantorian micro spacetime. This new interpretation complime...A basically topological interpretation of the Casimir effect is given as a natural intrinsic property of the geometrical topological structure of the quantum-Cantorian micro spacetime. This new interpretation compliments the earlier conventional interpretation as vacuum fluctuation or as a Schwinger source and links the Casimir energy to the so called missing dark energy density of the cosmos. We start with a general outline of the theoretical principle and basic design concepts of a proposed Casimir dark energy nano reactor. In a nutshell the theory and consequently the actual design depends crucially upon the equivalence between the dark energy density of the cosmos and the faint local Casimir effect produced by two sides boundary condition quantum waves. This Casimir effect is then colossally amplified as a one sided quantum wave pushing from the inside on the one sided M?bius-like boundary with nothing balancing it from the non-existent outside. In view of the present theory, this one sided M?bius-like boundary of the holographic boundary of the universe is essentially what leads to the observed accelerated expansion of the cosmos. Thus in principle we will restructure the local topology of space using material nanoscience technology to create an artificial local high dimensionality with a Dvoretzky theorem like volume measure concentration. Needless to say the entire design is based completely on the theory of quantum wave dark energy proposed by the present author. The quintessence of the present theory is easily explained as the intrinsic Casimir topological energy where produced from the zero set of the quantum particle when we extract the empty set quantum wave from it and find by restructuring space via plates similar to that of the classical Casimir experiments but with some modification.展开更多
Mesoporous superacids S2O82–-Fe2O3/SBA-15(SFS)with active nanoparticles are prepared by ultrasonic adsorption method.This method is adopted to ensure a homo-dispersed nanoparticle active phase,large specific surface ...Mesoporous superacids S2O82–-Fe2O3/SBA-15(SFS)with active nanoparticles are prepared by ultrasonic adsorption method.This method is adopted to ensure a homo-dispersed nanoparticle active phase,large specific surface area and many acidic sites.Compared with bulk S2O82–-Fe2O3,Br?nsted acid catalysts and other reported catalysts,SFS with an Fe2O3 loading of 30%(SFS-30)exhibits an outstanding activity in the probe reaction of alcoholysis of styrene oxide by methanol with 100%yield.Moreover,SFS-30 also shows a more excellent catalytic performance than bulk S2O82–-Fe2O3 towards the alcoholysis of other ROHs(R=C2H5-C4H9).Lewis and Bronsted acid sites on the SFS-30 surfaces are confirmed by pyridine adsorbed infrared spectra.The highly efficient catalytic activity of SFS-30 may be attributed to the synergistic effect from the nano-effect of S2O82–-Fe2O3 nanoparticles and the mesostructure of SBA-15.Finally,SFS-30 shows a good catalytic reusability,providing an 84.1%yield after seven catalytic cycles.展开更多
Six kinds of micro bridge-beam specimens with different sizes are fabricated using photolithography technology for bending test. Beam specimens with trapezoidal section could be representatives of those with rectangle...Six kinds of micro bridge-beam specimens with different sizes are fabricated using photolithography technology for bending test. Beam specimens with trapezoidal section could be representatives of those with rectangle and square section, which are usually applied in MEMS. Nano indentation method used in bending test can be applied to both elastic and plastic materials. Also, some mechanical properties parameters such as the modulus of elasticity, hardness and the bending strength are obtained. The average modulus of elasticity of SCS is 170.295 0±2.485 0 GPa, showing no size effects, but the bending strength ranges from 3.24 GPa to 10.15 GPa, displaying strong size effects, and the average hardness is 9.496 7±1.753 3 GPa,in which no obvious size effects are observed.展开更多
基金the National High Technology Research and Development Program of China(Grant No.2009AA063003)the National Nature Science Foundation of China(Grant No.20677039) for financial support
文摘A significant promotion effect of low-molecular hydroxyl compounds(LMHCs) was found in the nano-photoelectrocatalytic(NPEC) degradation of fulvic acid(FA),which is a typical kind of humic acid existing widely in natural water bodies,and its influence mechanism was proposed.A TiO_2 nanotube arrays(TNAs) material is served as the photoanode.Methanol,ethanediol,and glycerol were chosen as the representative of LMHCs in this study.The adsorption performance of organics on the surface of TNAs was investigated by using the instantaneous photocurrent value.The adsorption constants of FA,methanol,ethanediol,and glycerol were 43.44,19.32,7.00,and 1.30,respectively,which indicates that FA has the strongest adsorption property.The degradation performance of these organics and their mixture were observed in a thin-layer reactor.It shows that FA could hardly achieve exhausted mineralization alone,while LMHCs could be easily oxidized completely in the same condition.The degradation degree of FA,which is added LMHCs,improves significantly and the best promotion effect is achieved by glycerol.The promotion effect of LMHCs in the degradation of FA could be contributed to the formation of a tremendous amount of hydroxyl radicals in the NPEC process.The hydroxyl radicals could facilitate the complete degradation of both FA and its intermediate products.Among the chosen LMHCs,glycerol molecule which has three hydroxyls could generate the most hydroxyl radicals and contribute the best effective promotion.This work provides a new way to promote the NPEC degradation of FA and a direction to remove humus from polluted water.
文摘The 96 h acute toxic effects of nano-CuO (N-CuO), micro-CuO (M-CuO) and 2+ on Chlorella sp. were investigated in this paper. The results showed that toxicities decreased in an order of Cu2+>N-CuO>M-CuO. The 96 h EC50 of Cu2+ on Chlorella sp. was 1.06 mg /L, and of N-CuO it was 74.61 mg /L, while no pronounced toxicity was observed when the concentration of M-CuO was lower than 160 mg/L. Further experiments were carried out in order to study the toxicity mechanism of nano-CuO on Chlorella sp.. The results of Cu2+ release from N-CuO showed less than 0.2 mg/L Cu2+ were released, so the release of Cu2+ was not responsible for the toxicity. Further experiments showed N-CuO inhibited formation of Chlorophyll A. Content of Chlorophyll A in the control group was 4.75 mg/108 cells, while it declined to 2.89 mg/108 cells for 160 mg/L N-CuO after 96 h, which indicated that N-CuO could inhibit photosynthesis of Chlorella sp.. Moreover, N-CuO condensed with algal cells. It affected the activity of SOD and POD, indicating that N-CuO could cause oxidant stress to Chlorella sp.. These may be the toxicity mechanism.
文摘This paper deals with the study of the temperature effect on the nonlinear vibration behavior of nanoplate-based nano electromechanical systems（NEMS） subjected to hydrostatic and electrostatic actuations. Using Eringen＇s nonlocal elasticity and Gurtin–Murdoch theory, the nonlocal plate model is derived through Hamilton＇s principle. The governing equation which is extremely nonlinear due to the geometrical nonlinearity and electrostatic attraction forces is solved numerically using the differential quadrature method（DQM）. The accuracy of the present method is veriied by comparing the obtained results with the experimental data and those in the literature and very good agreement is obtained. Finally a comprehensive study is carried out to determine the inluence of temperature on the nonlinear vibration characteristics of NEMS made of two different materials including aluminum（Al）and silicon（Si） and some conclusions are drawn.
基金Funded by the National Natural Science Foundation of China(No.51579159)
文摘Cell surface of aquatic organisms constitutes a primary site for the interaction and a barrier for the nano-TiO2 biological effects.In the present study,the biological effects of nano-TiO2 on a unicellular green algae Chlamydomonas reinhardtii were studied by observing the changes of the cell surface morphology and functional groups under UV or natural light.By SEM,the cell surface morphology of C.reinhardtii was changed under UV light,nano-TiO2 with UV light or natural light,which indicated that photocatalysis damaged cell surface.It was also observed that cell surface was surrounded by TiO2 nanoparticles.The ATR-FTIR spectra showed that the peaks of functional groups such as C-N,-C=O,-C-O-C and P=O,which were the important components of cell wall and membrane,were all depressed by the photocatalysis of nano-TiO2 under UV light or natural light.The photocatalysis of nano-TiO2 promoted peroxidation of functional groups on the surface of C.reinhardtii cells,which led to the damages of cell wall and membrane.
基金the National High Technology Research and Development Program of China (Grant No.2009AA063003)the National Nature Science Foundation of China (No.20677039) for financial support
文摘The inhibition effect of tert-butyl alcohol(TBA), identified as the·OH radical inhibitor, on the TiO_2 nano assays(TNA) photoelectrocatalytic oxidation of different organics such as glucose and phthalate was reported. The adsorption performance of these organics on the TNA photoelectrode was investigated by using the instantaneous photocurrent value, and the degradation property was examined by using the exhausted reaction. The results showed that glucose exhibited the poor adsorption and easy degradation performance, phthalate showed the strong adsorption and harddegradation, but TBA showed the weak adsorption and was the most difficult to be degraded. The degradation of both glucose and phthalate could be inhibited evidently by TBA. But the effect on glucose was more obvious. The different inhibition effects of TBA on different organics could be attributed to the differences in the adsorption and the degradation property. For instance, phthalate of the strong adsorption property could avoid from the capture of·OH radicals by TBA in TNA photoelectrocatalytic process.
基金Project supported by the Postdoctoral Research Funds of Jiangsu Province, China (Grant No. 1002008B)the China Postdoctoral Science Foundation (Grant No. 20110491416)
文摘The model of a screw dislocation near a semi-infinite wedge crack tip inside a nano-circular inclusion is proposed to investigate the shielding effect of nano inclusions acting on cracks. Utilizing the complex function method, the closed-form solutions of the stress fields in the matrix and the inclusion region are derived. The stress intensity factor, the image force, as well as the critical loads for dislocation emission are discussed in detail. The results show that the nano inclusion not only enhances the shielding effect exerted by the dislocation, but also provides a shielding effect itself. Moreover, dislocations may be trapped in the nano inclusion even if the matrix is softer than the inclusion. This helps the dislocation shield crack, and reduces the dislocation density within the matrix.
文摘The coating and deposition process with excellent anti wear and suitable for industrial application were developed, and the optimum bath composition and process were obtained by studying the influence of the bath composition, temperature and pH value on the deposition rate and the plating solution stability. Moreover, the tribological properties of nano-Cu lubricating additives and electroless deposited Ni-W-P coating as well as their synergistic effect are researched using ring-block abrasion testing machine and energy dispersive spectrometer. Research results show that Ni-W-P alloy coating and nano-Cu lubricating additive have excellent synergistic effect, e g, the wear resistance of Ni-W-P alloy coating （with heat treatment and the oil with nano-Cu additives） has increased hundreds times than 45 steel as the metal substrate with the basic oil, and zero wear is achieved, which breaks through the bottleneck of previous separate research of the above-mentioned two aspects.
文摘The nano-titanium dioxide (nano-TiO_2) sensing membrane,fabricated by sol-gel technology,was used as the pH-sensing layer of the extended gate field effect transistor (EGFET) device.The objective of this research is the preparation of titanium dioxide materials by sol-gel method using Ti(OBu)_4 as the precursor.In this study,we fabricated a nano-titanium dioxide sensing layer on the ITO glass by dip coating.In order to examine the sensitivity of the nano-TiO_2 films applied to the EGFET devices,we adopted the ITO glass as substrate,and measured theⅠ_(DS)-Ⅴ_G curves of the nano-titanium dioxide separative structure EGFET device in the pH buffer solutions that have different pH values by the Keithley 236 Instrument.By the experimental results,we can obtain the pH sensitivities of the EGFET with nano-TiO_2 sensing membrane prepared by sol-gel method,which is 59.86mV/pH from pH 1 to pH 9.
文摘The major solving ways for the material wear are surface modification and lubrication. Currently, the researches at home and abroad are all limited to the single study of either nano-lubricating oil additive or electroless deposited coating. The surface coating has high hardness and high wear resistance, however, the friction reduction performance of the coating with high hardness is not good, the thickness of the coating is limited, and the coating can not regenerate after wearing. The nano-lubricating additives have good tribological performance and self-repair function, but under heavy load, the self-repair rate to the worn surface with the nano-additives is smaller than the wearing rate of the friction pair. To solve the above problems, the Ni-W-P alloy coating and deposition process with excellent anti-wear, and suitable for industrial application were developed, the optimum bath composition and process can be obtained by studying the influence of the bath composition, temperature and PH value to the deposition rate and the plating solution stability. The tribological properties as well as anti-wear and friction reduction mechanism of wear self-repair nano-ceramic lubricating additives are also studied. The ring-block abrasion testing machine and energy dispersive spectrometer are used to explore the internal relation between the coating and the nano-lubricating oil additives, and the tribology mechanism, to seek the synergetic effect between the two. The test results show that the wear resistance of Ni-W-P alloy coating （with heat treatment and in oil with nano-ceramic additives） has increased hundreds times than 45 steel as the metal substrate in basic oil, the friction reduction performance is improved. This research breaks through the bottleneck of previous separate research of the above-mentioned two methods, and explores the combination use of the two methods in industrial field.
基金Supported by Program of Local Specialty Crop Varieties and Protective Cultivation Technique in Foshan City(Agricultural Technology Extension Project of Foshan City in 2017-2018)Characteristic Vegetable Innovation Team of Modern Agricultural Industrial Technology System of Guangdong Province(2016LM1015)
文摘[Objectives] This study was carried out to explore the selenium-enriching effect of different crops, and provide certain references for production of selenium-enriched agricultural products. [Methods] Four kinds of crops （tomato, leaf mustard, peanut, and carrot） were exogenous selenium fertilizer treated, to explore the selenium-enriching effects on these crops. [Results] Exogenous application of microbial nano-selenium can significantly increase the selenium content of the crops, of which the effects on big tomato （Weiyanuo） were the best. After spraying, the selenium content increased by 1.39 times, and at the same time the sugar content of tomato was also increased. [Conclusions] This study is expected to provide references for increase of the selenium content of agricultural products.
文摘Using alkalescent ammonium(AAC)as precipitatnt, the diameter of nano La_2O_3 powder with diameter in 80 nm and less was prepared by the method of homogeneous precipitation, and reactant concentration, temperature and pH were studied and confirmed. The best precipitated concentration is from 0.2 to 0.5 mol·L^(-1), and the diameter of compounded powder turns small as the temperature gradually becomes high, and the pH from 6 to 8 is the best and the concentration of precipitant does not affect the diameter of compounded powder significantly. Meanwhile, most experiments lasting for fifty days in the greenhouse, and the results are 0.2 g·kg^(-1) nano La_2O_3 powder is enorgh for increasing biomass by 133% compared with that of the CK.
基金Project supported by the National Basic Research Program of China(No.2011CB610300)the 111 Project of China(No.B07050)+3 种基金the National Natural Science Foundation of China(Nos.10972182, 11172239,and 10902089)the Doctoral Program Foundation of Education Ministry of China (No.20106102110019)the Open Foundation of State Key Laboratory of Structural Analysis of Industrial Equipment of China(No.GZ0802)the Doctorate Foundation of Northwestern Polytechnical University of China(No.CX201111)
文摘The governing differential equation of micro/nanbeams with atom/molecule adsorption is derived in the presence of surface effects using the nonlocal elasticity. The effects of the nonlocal parameter, the adsorption density, and the surface parameter on the resonant frequency of the micro/nanobeams are investigated. It is found that, in ad- dition to the nonlocal parameter and the surface parameter, the bending rigidity and the adsorption-induced mass exhibit different behaviors with the increase in the adsorption density depending on the adatom category and the substrate material.
文摘A basically topological interpretation of the Casimir effect is given as a natural intrinsic property of the geometrical topological structure of the quantum-Cantorian micro spacetime. This new interpretation compliments the earlier conventional interpretation as vacuum fluctuation or as a Schwinger source and links the Casimir energy to the so called missing dark energy density of the cosmos. We start with a general outline of the theoretical principle and basic design concepts of a proposed Casimir dark energy nano reactor. In a nutshell the theory and consequently the actual design depends crucially upon the equivalence between the dark energy density of the cosmos and the faint local Casimir effect produced by two sides boundary condition quantum waves. This Casimir effect is then colossally amplified as a one sided quantum wave pushing from the inside on the one sided M?bius-like boundary with nothing balancing it from the non-existent outside. In view of the present theory, this one sided M?bius-like boundary of the holographic boundary of the universe is essentially what leads to the observed accelerated expansion of the cosmos. Thus in principle we will restructure the local topology of space using material nanoscience technology to create an artificial local high dimensionality with a Dvoretzky theorem like volume measure concentration. Needless to say the entire design is based completely on the theory of quantum wave dark energy proposed by the present author. The quintessence of the present theory is easily explained as the intrinsic Casimir topological energy where produced from the zero set of the quantum particle when we extract the empty set quantum wave from it and find by restructuring space via plates similar to that of the classical Casimir experiments but with some modification.
文摘Mesoporous superacids S2O82–-Fe2O3/SBA-15(SFS)with active nanoparticles are prepared by ultrasonic adsorption method.This method is adopted to ensure a homo-dispersed nanoparticle active phase,large specific surface area and many acidic sites.Compared with bulk S2O82–-Fe2O3,Br?nsted acid catalysts and other reported catalysts,SFS with an Fe2O3 loading of 30%(SFS-30)exhibits an outstanding activity in the probe reaction of alcoholysis of styrene oxide by methanol with 100%yield.Moreover,SFS-30 also shows a more excellent catalytic performance than bulk S2O82–-Fe2O3 towards the alcoholysis of other ROHs(R=C2H5-C4H9).Lewis and Bronsted acid sites on the SFS-30 surfaces are confirmed by pyridine adsorbed infrared spectra.The highly efficient catalytic activity of SFS-30 may be attributed to the synergistic effect from the nano-effect of S2O82–-Fe2O3 nanoparticles and the mesostructure of SBA-15.Finally,SFS-30 shows a good catalytic reusability,providing an 84.1%yield after seven catalytic cycles.
文摘Six kinds of micro bridge-beam specimens with different sizes are fabricated using photolithography technology for bending test. Beam specimens with trapezoidal section could be representatives of those with rectangle and square section, which are usually applied in MEMS. Nano indentation method used in bending test can be applied to both elastic and plastic materials. Also, some mechanical properties parameters such as the modulus of elasticity, hardness and the bending strength are obtained. The average modulus of elasticity of SCS is 170.295 0±2.485 0 GPa, showing no size effects, but the bending strength ranges from 3.24 GPa to 10.15 GPa, displaying strong size effects, and the average hardness is 9.496 7±1.753 3 GPa,in which no obvious size effects are observed.
