Different planning methods have been applied in private and public infrastructure projects, which resulted in different approval procedures and querry about impartiality. However, planning methods of infrastructure pr...Different planning methods have been applied in private and public infrastructure projects, which resulted in different approval procedures and querry about impartiality. However, planning methods of infrastructure projects are seldom investigated up to now. The authors propose a proper project planning method which is applicable to all kinds of infrastructure projects with various funedorigins. The project planning method includes a comprehensive planning frame- work and a six-step planning process. The financial indicator, i. e. , self-reimbursement ratio is introduced for the proper division of financial obligation between government and project company.展开更多
Anisotropic materials, like carbon nanotubes(CNTs), are the perfect substitutes to overcome the limitations of conventional metamaterials; however, the successful fabrication of CNT forest metamaterial structures is s...Anisotropic materials, like carbon nanotubes(CNTs), are the perfect substitutes to overcome the limitations of conventional metamaterials; however, the successful fabrication of CNT forest metamaterial structures is still very challenging. In this study, a new method utilizing a focused ion beam(FIB) with additional secondary etching is presented, which can obtain uniform and fine patterning of CNT forest nanostructures for metamaterials and ranging in sizes from hundreds of nanometers to several micrometers. The influence of the FIB processing parameters on the morphology of the catalyst surface and the growth of the CNT forest was investigated, including the removal of redeposited material,decreasing the average surface roughness(from 0.45 to 0.15 nm), and a decrease in the thickness of the Fe catalyst.The results showed that the combination of FIB patterning and secondary etching enabled the growth of highly aligned, highdensity CNT forest metamaterials. The improvement in the quality of single-walled CNTs(SWNTs), defined by the very high G/D peak ratio intensity of 10.47, demonstrated successful fine patterning of CNT forest for the first time. With a FIB patterning depth of 10 nm and a secondary etching of 0.5 nm, a minimum size of 150 nm of CNT forest metamaterials was achieved. The development of the FIB secondary etching method enabled for the first time, the fabrication of SWNT forest metamaterials for the optical and infrared regime, for future applications, e.g., in superlenses, antennas,or thermal metamaterials.展开更多
Iron sulfide is an important reductive pollutant in aquatic sediment,so that increasing attentions have been paid to it in recent years.In this paper,the formation of iron sulfide in water-body sediment was introduced...Iron sulfide is an important reductive pollutant in aquatic sediment,so that increasing attentions have been paid to it in recent years.In this paper,the formation of iron sulfide in water-body sediment was introduced.Moreover,its adverse influences upon environment were summarized,including direct contribution to deficiency of dissolved oxygen in water,association with eutrophication in water-bodies and impact on geochemical sulfur cycle.Since conventional chemical analysis for iron sulfide has several disadvantages,new technique for rapid determination of iron sulfide on-line was prospected.展开更多
Evaluation of creep properties of the welded joint through taking local fluctuation of the mechanical properties into consideration is experimentally or analytically seldom carried out. The purposes of the present stu...Evaluation of creep properties of the welded joint through taking local fluctuation of the mechanical properties into consideration is experimentally or analytically seldom carried out. The purposes of the present study are to examine the surface strain distribution in the weld metal of a full thickness welded joint specimen and subsequently to investigate the local variation in the properties of the all-weld metal part of the joint using miniature specimens. A welded joint was prepared for 316FR steel plates by gas tungsten arc welding process using Mod. 316L filler wire. Creep tests were conducted at 823K in air using full thickness large welded joint specimens, HAZ and all-weld metal miniature specimens. From the results obtained, it is concluded that the creep properties of multi-layer welded joints strongly depend on the location of specimen sampling.展开更多
We investigate the flow induced by annihilation of a pair of defects in liquid crystals using the Doi theory with the Marrucci-Greco potential, in which the orientation state is described with the orientational distri...We investigate the flow induced by annihilation of a pair of defects in liquid crystals using the Doi theory with the Marrucci-Greco potential, in which the orientation state is described with the orientational distribution function. We have numerically studied both the transient behaviors of two defects with different structures and their velocity field, and estimated the magnitude of the induced velocity. A defect with positive strength moves faster than one with negative strength. The long-range order of the molecular orientation field has a large effect on the annihilation time, and the annihilation time is reduced by increasing the long-range order. We find that flows are induced during the annihilation of a pair of defects and that several vortices are generated in the vicinity of the defects. The maximum velocity is predicted to develop spatially between the two defects just after their annihilation in time. In our simulation, the maximum induced velocity reaches an order of 10 μm/s. The induced velocity increases with increasing long range-order and nematic potential strength.展开更多
Many prior research findings indicate that audit quality differs between the Big 4 and non-Big 4 audit firms using an indicator variable. However, most previous research focuses on only outcome measures, such as audit...Many prior research findings indicate that audit quality differs between the Big 4 and non-Big 4 audit firms using an indicator variable. However, most previous research focuses on only outcome measures, such as audit fees, going concern reports, and non-audit services. This study investigates audit quality differentiation between the Big 4 and non-Big 4 audit firms hypothesis from an audit objective point of view. One of the material objectives of Japanese internal control audit institutions is to facilitate assessment and improvement of internal controls by corporations themselves. The findings of this study indicate that the Big 4 audit firms accomplish this objective better than non-Big 4 audit firms. Consequently, most Big 4 clients do not disclose significant deficiencies （SDs）, implying that they improve the quality of internal controls through internal controls auditing. This paper concludes that Big 4 firms produce a higher audit quality level than non-Big 4 firms, and this quality difference iS related to how an audit objective is interpreted and implemented.展开更多
Mathematical frameworks of quantum theory have recently been adopted in cognitive and behavioral sciences, to explain the violations of normative decision theory and anomalies in cognition. However, to date, no study ...Mathematical frameworks of quantum theory have recently been adopted in cognitive and behavioral sciences, to explain the violations of normative decision theory and anomalies in cognition. However, to date, no study has attempted to explore neural implementations of such “quantum-like” information processing in the brain. This study demonstrates that neural population coding of information with nonlinear neural response functions can account for such “quantum” information processing in decision-making and cognition. It is also shown that quantum decision theory is a special case of more general population vector cording theory. Future applications of the present theory in the rapidly evolving field of “psychophysical neuroeconomics” are also discussed.展开更多
Methyl methacrylate (MMA) was successfully grafted onto cellulose nanofibers (CNFs) at room temperature in an emulsion system using a diethyl(1,10-<span style="font-family:;" "=""><sp...Methyl methacrylate (MMA) was successfully grafted onto cellulose nanofibers (CNFs) at room temperature in an emulsion system using a diethyl(1,10-<span style="font-family:;" "=""><span style="font-family:Verdana;">phenanthroline </span><i><span style="font-family:Verdana;">N</span></i><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;">,</span><i><span style="font-family:Verdana;">N</span></i><sub><span style="font-family:Verdana;">10</span></sub><span style="font-family:Verdana;">)zinc(</span></span><span style="font-family:Verdana;">II</span><span style="font-family:Verdana;">) complex (Phen</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">DEZ) with oxygen as the radical initiator. The effects of reaction temperature, initiator concentration, and monomer content on the grafting reaction were investigated. The molecular weight of the non-grafted PMMA, which was produced during graft polymerization, was more than 1 million, as determined by size exclusion chromatography. The PMMA-grafted CNFs were analyzed by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy, which confirmed the grafting of PMMA on the nanofiber surface. The study presents a strategy for the grafting of high-molecular weight PMMA onto CNFs in an emulsion system</span><span style="font-family:Verdana;"> using</span><span> Phen</span><span>-</span><span><span>DEZ and</span></span><span><span> O</span><sub><span>2</span></sub><span>.</span></span>展开更多
Water plays an important role in food production especially rice. Rice productivity depends greatly on sufficient water to meet evaporative demand and soil moisture. It is certain thalL rice, the most important crop o...Water plays an important role in food production especially rice. Rice productivity depends greatly on sufficient water to meet evaporative demand and soil moisture. It is certain thalL rice, the most important crop of Thailand and Vietnam, is vulnerable to climate change. This paper proposes an analysis on the impact of climate on rice water requirement and food security in Thailand and Vietnam. Water demand, yield and production of rice were computed under the changed surface air temperature for three time slices, namely 2020s, 2050s and 2080s. Food security was analyzed from rice supply （calculated milled-rice product, rice stock, and imports） and demand （domestic uses from population growth, exports to world market, domestic seed and other uses）. The result showed that, under the higher surface air temperature scenario, water requirement office in Thailand and Vietnam could increase by 1.8 times in the end of the 21 st century. Production of rice dropped by declined yield. Thailand and Vietnam which is the world largest rice exporter in last decades will face the rice shortage in 2080s and 2030s respectively.展开更多
This paper discusses the data-driven design of linear quadratic regulators,i.e.,to obtain the regulators directly from experimental data without using the models of plants.In particular,we aim to improve an existing d...This paper discusses the data-driven design of linear quadratic regulators,i.e.,to obtain the regulators directly from experimental data without using the models of plants.In particular,we aim to improve an existing design method by reducing the amount of the required experimental data.Reducing the data amount leads to the cost reduction of experiments and computation for the data-driven design.We present a simplified version of the existing method,where parameters yielding the gain of the regulator are estimated from only part of the data required in the existing method.We then show that the data amount required in the presented method is less than half of that in the existing method under certain conditions.In addition,assuming the presence of measurement noise,we analyze the relations between the expectations and variances of the estimated parameters and the noise.As a result,it is shown that using a larger amount of the experimental data might mitigate the effects of the noise on the estimated parameters.These results are verified by numerical examples.展开更多
Mobile ad hoc networks are particularly vulnerable to denial of service （DOS） attacks launched through compromised nodes or intruders. In this paper, we present a new DOS attack and its defense in ad hoc networks. T...Mobile ad hoc networks are particularly vulnerable to denial of service （DOS） attacks launched through compromised nodes or intruders. In this paper, we present a new DOS attack and its defense in ad hoc networks. The new DOS attack, called AA hoc Flooding Attack（AHFA）, is that intruder broadcasts mass Route Request packets to exhaust the communication bandwidth and node resource so that the valid communication can not be kept. After analyzed AM hoc Flooding Attack, we develop Flooding Attack Prevention （FAP）, a genetic defense against the AM hoc Flooding Attack. When the intruder broadcasts exceeding packets of Route Request, the immediate neighbors of the intruder record the rate of Route Request. Once the threshold is exceeded, nodes deny any future request packets from the intruder. The results of our implementation show FAP can prevent the AM hoe Flooding attack efficiently.展开更多
Characteristic features of infrasound waves observed in the Antarctic represent a physical interaction relating surface environment in the continental margin and surrounding Southern Ocean. Source location of several ...Characteristic features of infrasound waves observed in the Antarctic represent a physical interaction relating surface environment in the continental margin and surrounding Southern Ocean. Source location of several infrasound events is demonstrated by using combination of two array deployments along a coast of the Lützow-Holm Bay (LHB), East Antarctica, for data retrieving period in January-June 2015. These infrasound arrays being established in January 2013 clearly detected temporal variations in frequency content and propagation direction of the identified seven large events. Many of these sources are assumed to have cryoseismic origins;the ice-quakes associated with calving of glaciers, discharge of sea-ice, collision between sea-ice and icebergs around the LHB. Detail and continuous measurements of infrasound waves in the Antarctic are a proxy for monitoring regional environment as well as climate change in high southern latitude.展开更多
Characteristic infrasound waves observed at Antarctic stations demonstrate physical interaction involving environmental changes in the Antarctic continent and the surrounding oceans. A Chaparraltype infrasound sensor ...Characteristic infrasound waves observed at Antarctic stations demonstrate physical interaction involving environmental changes in the Antarctic continent and the surrounding oceans. A Chaparraltype infrasound sensor was installed at Syowa Station （SYO; 39°E, 69°S）, East Antarctica, as one of the projects of the International Polar Year （IPY2007-2008）. Data continuously recorded during the three seasons in 2008-2010 clearly indicate a contamination of the background oceanic signals （microbaroms） with peaks between 4 and 10 s observed during a whole season. The peak amplitudes of the microbaroms have relatively lower values during austral winters, caused by a larger amount of sea-ice extending around the Lutzow-Holm Bay near SYO, with decreasing ocean wave loading effects. Micro- baroms measurements are useful tool for characterizing ocean wave climate, complementing other oceanographic and geophysical data. A continuous monitoring by infrasound sensors in the Antarctic firmly contributes to the Comprehensive Nuclear-Test-Ban Treaty （CTBT） in the southern high latitude, together with the Pan-Antarctic Observations System （PAntOS） under the Scientific Committee on Antarctic Research （SCAR）. Detailed measurements of the infrasound waves in Antarctica, consequently, could be a new proxy for monitoring regional environmental change as well as the temporal climate variations in the polar regions.展开更多
Methyl methacrylate (MMA) was grafted onto silk fiber in a one-step emulsion system using a diethylzinc and 1,10-phenanthroline complex. The reaction conditions were investigated by varying temperature and initiator t...Methyl methacrylate (MMA) was grafted onto silk fiber in a one-step emulsion system using a diethylzinc and 1,10-phenanthroline complex. The reaction conditions were investigated by varying temperature and initiator to monomer ratio. Fourier transform infrared (FTIR) spectrum, thermogravimetric analysis (TGA), and scanning electron microscopy (SEC) techniques were used to characterize the structure, thermal stability, and surface morphology of the obtained product, respectively. Grafting of MMA onto silk increased the thermal stability of silk. The FTIR spectrum and SEM images provided further evidence that MMA has been successfully grafted onto the silk fiber. A peak ascribed to the C=O stretching vibration of MMA was detected in the FTIR spectrum of grafted silk fiber, which was not present in the spectrum of pure silk fiber. Moreover, the SEM images illustrated the increase in diameter and surface roughness of grafted silk compared with pure silk. Lastly, the dyeing performance of the modified silk was significantly increased.展开更多
Characteristics and statistics of seismic tremors occurring during April 2015 were investigated by using short-period and broadband seismographs deployed at Syowa Station (SYO), in the Lützow-Holm Bay (LHB), East...Characteristics and statistics of seismic tremors occurring during April 2015 were investigated by using short-period and broadband seismographs deployed at Syowa Station (SYO), in the Lützow-Holm Bay (LHB), East Antarctica. In order to examine a relationship between surface environments in particular cryosphere variation, the MODIS satellite images were utilized for comparison with the detected tremor events. Since a large volume of sea-ice was discharged during the April, together with several large icebergs passed through from the west to the east at northern edge of the fast sea-ice of LHB, it was expected to detect seismic tremors involving cryospehre dynamics. During the month, a total number of 49 tremor events including short duration ice shocks were identified. Majority of the events (N = 39) had their duration times more than 15 minutes, which were divided into both tremors and ice shocks on the basis of experienced definition at SYO. Cryospheric sources recorded by seismic tremors were classified into several origins (collision, calving, crevassing, crashing, etc.): “crevassing events” along the large cracks inside the fast sea-ice in LHB (04 April), “discharge events” of fast sea-ice from the Bay (07 April), “collision events” between iceberg and the edge of fast sea-ice (14 April), “crashing movement” between fragmentation of fast sea-ice and packed sea-ice (18 April), and other origins. In particular, strong amplitude tremors with harmonic overtones were assumed to be occurred independently from whether condition, because these overtone tremors were identified at less stormy days by comparison with infrasound data at SYO.展开更多
Dye-sensitized titanium oxide electrodes were prepared by immobilizing a novel ruthenium complex, di(isothiocy- anato)bis(4-methyl-4’-vinyl-2,2’-bipyridine)ruthenium(II) [(NCS)2(mvbpy)2Ru(II)] or the ruthenium compl...Dye-sensitized titanium oxide electrodes were prepared by immobilizing a novel ruthenium complex, di(isothiocy- anato)bis(4-methyl-4’-vinyl-2,2’-bipyridine)ruthenium(II) [(NCS)2(mvbpy)2Ru(II)] or the ruthenium complex/sodium 4-vinylbenzenesulfonate onto the surface of a titanium oxide-coated, fluorine-doped tin oxide (TiO2/FTO) electrode through a new electrochemically initiated film formation method, in which the electrolysis step and the film deposition step were individually performed. The incident photon-to-current conversion efficiency (IPCE) of the Ru complex film on a TiO2/FTO electrode was disappointedly insufficient (1.2% at 440 nm). In sharp contrast, the Ru(II) complex/so- dium 4-vinylbenzenesulfonate composite film deposited on the surface of a TiO2/FTO electrode showed maximum IPCE of 31.7% at 438 nm.展开更多
The Keras deep learning framework is employed to study MRI brain data in a preliminary analysis of brain structure using a convolutional neural network.The results obtained are matched with the content of personality ...The Keras deep learning framework is employed to study MRI brain data in a preliminary analysis of brain structure using a convolutional neural network.The results obtained are matched with the content of personality questionnaires.The Big Five personality traits provide easy differentiation for dividing personalities into different groups.Until now,the highest accuracy obtained from the results of personality prediction from the analysis of brain structure is about 70%.Although there is still no effective evidence to prove a clear relationship between brain structure and personality,the obtained results could prove helpful in understanding the basic relationship between brain structure and personality characteristics.展开更多
Characteristic infrasound waves are clearly recorded at Syowa Station (SYO), East Antarctica, involving physical interaction in surrounding environments at the continent and SouthernOcean. A Chaparral microphone type ...Characteristic infrasound waves are clearly recorded at Syowa Station (SYO), East Antarctica, involving physical interaction in surrounding environments at the continent and SouthernOcean. A Chaparral microphone type infrasound sensor is deployed at SYO during the International Polar Year (IPY2007-2008), the most diverse international science program held recently. Continuous recorded data in 2008-2010 indicate a contamination of background oceanic signals (microbaroms). The characteristic signals are identified as the “microbaroms” with peaks between 4 and 10 s in the records. The peak amplitudes of microbaroms may be enhanced by the extratropical cyclonic storms and wind noises in Southern Ocean. The microbaroms has relatively lower amplitudes during austral winters, which may be caused by the larger amount of the sea-ice extent around theLützow-HolmBaynear SYO, with decreasing the ocean wave loading effects. In addition, the large energy with intrinsic periods between 12 and 30 s are observable under excellent storm conditions, particularly in local winter. The oceanic effects appearing on infrasound data are modulated by the presence of sea-ice and explained by a relationship between the atmosphere-ocean-cryosphere systems. Microbaroms measurements could be a useful tool for characterizing ocean wave climate, as well as a new proxy for monitoring a regional environmental variation inAntarctica.展开更多
基金Science Foundation of Jimei University(No.ZQ2007027)Youth Talent Program of Department of Science and Technology of Fujian Province(No.2008F3072)
文摘Different planning methods have been applied in private and public infrastructure projects, which resulted in different approval procedures and querry about impartiality. However, planning methods of infrastructure projects are seldom investigated up to now. The authors propose a proper project planning method which is applicable to all kinds of infrastructure projects with various funedorigins. The project planning method includes a comprehensive planning frame- work and a six-step planning process. The financial indicator, i. e. , self-reimbursement ratio is introduced for the proper division of financial obligation between government and project company.
文摘Anisotropic materials, like carbon nanotubes(CNTs), are the perfect substitutes to overcome the limitations of conventional metamaterials; however, the successful fabrication of CNT forest metamaterial structures is still very challenging. In this study, a new method utilizing a focused ion beam(FIB) with additional secondary etching is presented, which can obtain uniform and fine patterning of CNT forest nanostructures for metamaterials and ranging in sizes from hundreds of nanometers to several micrometers. The influence of the FIB processing parameters on the morphology of the catalyst surface and the growth of the CNT forest was investigated, including the removal of redeposited material,decreasing the average surface roughness(from 0.45 to 0.15 nm), and a decrease in the thickness of the Fe catalyst.The results showed that the combination of FIB patterning and secondary etching enabled the growth of highly aligned, highdensity CNT forest metamaterials. The improvement in the quality of single-walled CNTs(SWNTs), defined by the very high G/D peak ratio intensity of 10.47, demonstrated successful fine patterning of CNT forest for the first time. With a FIB patterning depth of 10 nm and a secondary etching of 0.5 nm, a minimum size of 150 nm of CNT forest metamaterials was achieved. The development of the FIB secondary etching method enabled for the first time, the fabrication of SWNT forest metamaterials for the optical and infrared regime, for future applications, e.g., in superlenses, antennas,or thermal metamaterials.
基金Supported by Homecoming Foundation of Heilongjiang Province(LC06C04)Researcher Overseas Foundation of the Department of Education of Heilongjiang Province(1152hq19)
文摘Iron sulfide is an important reductive pollutant in aquatic sediment,so that increasing attentions have been paid to it in recent years.In this paper,the formation of iron sulfide in water-body sediment was introduced.Moreover,its adverse influences upon environment were summarized,including direct contribution to deficiency of dissolved oxygen in water,association with eutrophication in water-bodies and impact on geochemical sulfur cycle.Since conventional chemical analysis for iron sulfide has several disadvantages,new technique for rapid determination of iron sulfide on-line was prospected.
基金supported by the Budget for Nuclear Research of the Ministry of Education,Culture,Sports,Science and Technology,Japan,based on the screening and counselling by the Atomic Energy Commission.
文摘Evaluation of creep properties of the welded joint through taking local fluctuation of the mechanical properties into consideration is experimentally or analytically seldom carried out. The purposes of the present study are to examine the surface strain distribution in the weld metal of a full thickness welded joint specimen and subsequently to investigate the local variation in the properties of the all-weld metal part of the joint using miniature specimens. A welded joint was prepared for 316FR steel plates by gas tungsten arc welding process using Mod. 316L filler wire. Creep tests were conducted at 823K in air using full thickness large welded joint specimens, HAZ and all-weld metal miniature specimens. From the results obtained, it is concluded that the creep properties of multi-layer welded joints strongly depend on the location of specimen sampling.
文摘We investigate the flow induced by annihilation of a pair of defects in liquid crystals using the Doi theory with the Marrucci-Greco potential, in which the orientation state is described with the orientational distribution function. We have numerically studied both the transient behaviors of two defects with different structures and their velocity field, and estimated the magnitude of the induced velocity. A defect with positive strength moves faster than one with negative strength. The long-range order of the molecular orientation field has a large effect on the annihilation time, and the annihilation time is reduced by increasing the long-range order. We find that flows are induced during the annihilation of a pair of defects and that several vortices are generated in the vicinity of the defects. The maximum velocity is predicted to develop spatially between the two defects just after their annihilation in time. In our simulation, the maximum induced velocity reaches an order of 10 μm/s. The induced velocity increases with increasing long range-order and nematic potential strength.
文摘Many prior research findings indicate that audit quality differs between the Big 4 and non-Big 4 audit firms using an indicator variable. However, most previous research focuses on only outcome measures, such as audit fees, going concern reports, and non-audit services. This study investigates audit quality differentiation between the Big 4 and non-Big 4 audit firms hypothesis from an audit objective point of view. One of the material objectives of Japanese internal control audit institutions is to facilitate assessment and improvement of internal controls by corporations themselves. The findings of this study indicate that the Big 4 audit firms accomplish this objective better than non-Big 4 audit firms. Consequently, most Big 4 clients do not disclose significant deficiencies （SDs）, implying that they improve the quality of internal controls through internal controls auditing. This paper concludes that Big 4 firms produce a higher audit quality level than non-Big 4 firms, and this quality difference iS related to how an audit objective is interpreted and implemented.
文摘Mathematical frameworks of quantum theory have recently been adopted in cognitive and behavioral sciences, to explain the violations of normative decision theory and anomalies in cognition. However, to date, no study has attempted to explore neural implementations of such “quantum-like” information processing in the brain. This study demonstrates that neural population coding of information with nonlinear neural response functions can account for such “quantum” information processing in decision-making and cognition. It is also shown that quantum decision theory is a special case of more general population vector cording theory. Future applications of the present theory in the rapidly evolving field of “psychophysical neuroeconomics” are also discussed.
文摘Methyl methacrylate (MMA) was successfully grafted onto cellulose nanofibers (CNFs) at room temperature in an emulsion system using a diethyl(1,10-<span style="font-family:;" "=""><span style="font-family:Verdana;">phenanthroline </span><i><span style="font-family:Verdana;">N</span></i><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;">,</span><i><span style="font-family:Verdana;">N</span></i><sub><span style="font-family:Verdana;">10</span></sub><span style="font-family:Verdana;">)zinc(</span></span><span style="font-family:Verdana;">II</span><span style="font-family:Verdana;">) complex (Phen</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">DEZ) with oxygen as the radical initiator. The effects of reaction temperature, initiator concentration, and monomer content on the grafting reaction were investigated. The molecular weight of the non-grafted PMMA, which was produced during graft polymerization, was more than 1 million, as determined by size exclusion chromatography. The PMMA-grafted CNFs were analyzed by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy, which confirmed the grafting of PMMA on the nanofiber surface. The study presents a strategy for the grafting of high-molecular weight PMMA onto CNFs in an emulsion system</span><span style="font-family:Verdana;"> using</span><span> Phen</span><span>-</span><span><span>DEZ and</span></span><span><span> O</span><sub><span>2</span></sub><span>.</span></span>
文摘Water plays an important role in food production especially rice. Rice productivity depends greatly on sufficient water to meet evaporative demand and soil moisture. It is certain thalL rice, the most important crop of Thailand and Vietnam, is vulnerable to climate change. This paper proposes an analysis on the impact of climate on rice water requirement and food security in Thailand and Vietnam. Water demand, yield and production of rice were computed under the changed surface air temperature for three time slices, namely 2020s, 2050s and 2080s. Food security was analyzed from rice supply （calculated milled-rice product, rice stock, and imports） and demand （domestic uses from population growth, exports to world market, domestic seed and other uses）. The result showed that, under the higher surface air temperature scenario, water requirement office in Thailand and Vietnam could increase by 1.8 times in the end of the 21 st century. Production of rice dropped by declined yield. Thailand and Vietnam which is the world largest rice exporter in last decades will face the rice shortage in 2080s and 2030s respectively.
文摘This paper discusses the data-driven design of linear quadratic regulators,i.e.,to obtain the regulators directly from experimental data without using the models of plants.In particular,we aim to improve an existing design method by reducing the amount of the required experimental data.Reducing the data amount leads to the cost reduction of experiments and computation for the data-driven design.We present a simplified version of the existing method,where parameters yielding the gain of the regulator are estimated from only part of the data required in the existing method.We then show that the data amount required in the presented method is less than half of that in the existing method under certain conditions.In addition,assuming the presence of measurement noise,we analyze the relations between the expectations and variances of the estimated parameters and the noise.As a result,it is shown that using a larger amount of the experimental data might mitigate the effects of the noise on the estimated parameters.These results are verified by numerical examples.
基金This project was supported by the National"863"High Technology Development Programof China (2003AA148010) Key Technologies R&D Programof China (2002DA103A03 -07)
文摘Mobile ad hoc networks are particularly vulnerable to denial of service （DOS） attacks launched through compromised nodes or intruders. In this paper, we present a new DOS attack and its defense in ad hoc networks. The new DOS attack, called AA hoc Flooding Attack（AHFA）, is that intruder broadcasts mass Route Request packets to exhaust the communication bandwidth and node resource so that the valid communication can not be kept. After analyzed AM hoc Flooding Attack, we develop Flooding Attack Prevention （FAP）, a genetic defense against the AM hoc Flooding Attack. When the intruder broadcasts exceeding packets of Route Request, the immediate neighbors of the intruder record the rate of Route Request. Once the threshold is exceeded, nodes deny any future request packets from the intruder. The results of our implementation show FAP can prevent the AM hoe Flooding attack efficiently.
文摘Characteristic features of infrasound waves observed in the Antarctic represent a physical interaction relating surface environment in the continental margin and surrounding Southern Ocean. Source location of several infrasound events is demonstrated by using combination of two array deployments along a coast of the Lützow-Holm Bay (LHB), East Antarctica, for data retrieving period in January-June 2015. These infrasound arrays being established in January 2013 clearly detected temporal variations in frequency content and propagation direction of the identified seven large events. Many of these sources are assumed to have cryoseismic origins;the ice-quakes associated with calving of glaciers, discharge of sea-ice, collision between sea-ice and icebergs around the LHB. Detail and continuous measurements of infrasound waves in the Antarctic are a proxy for monitoring regional environment as well as climate change in high southern latitude.
基金supported by the Ministry of Education,Science,Sports and Culture, Grant-in-Aid for Young Scientists(B) 19740265,2007(P.I.for Dr. Yoshiaki Ishihara)
文摘Characteristic infrasound waves observed at Antarctic stations demonstrate physical interaction involving environmental changes in the Antarctic continent and the surrounding oceans. A Chaparraltype infrasound sensor was installed at Syowa Station （SYO; 39°E, 69°S）, East Antarctica, as one of the projects of the International Polar Year （IPY2007-2008）. Data continuously recorded during the three seasons in 2008-2010 clearly indicate a contamination of the background oceanic signals （microbaroms） with peaks between 4 and 10 s observed during a whole season. The peak amplitudes of the microbaroms have relatively lower values during austral winters, caused by a larger amount of sea-ice extending around the Lutzow-Holm Bay near SYO, with decreasing ocean wave loading effects. Micro- baroms measurements are useful tool for characterizing ocean wave climate, complementing other oceanographic and geophysical data. A continuous monitoring by infrasound sensors in the Antarctic firmly contributes to the Comprehensive Nuclear-Test-Ban Treaty （CTBT） in the southern high latitude, together with the Pan-Antarctic Observations System （PAntOS） under the Scientific Committee on Antarctic Research （SCAR）. Detailed measurements of the infrasound waves in Antarctica, consequently, could be a new proxy for monitoring regional environmental change as well as the temporal climate variations in the polar regions.
文摘Methyl methacrylate (MMA) was grafted onto silk fiber in a one-step emulsion system using a diethylzinc and 1,10-phenanthroline complex. The reaction conditions were investigated by varying temperature and initiator to monomer ratio. Fourier transform infrared (FTIR) spectrum, thermogravimetric analysis (TGA), and scanning electron microscopy (SEC) techniques were used to characterize the structure, thermal stability, and surface morphology of the obtained product, respectively. Grafting of MMA onto silk increased the thermal stability of silk. The FTIR spectrum and SEM images provided further evidence that MMA has been successfully grafted onto the silk fiber. A peak ascribed to the C=O stretching vibration of MMA was detected in the FTIR spectrum of grafted silk fiber, which was not present in the spectrum of pure silk fiber. Moreover, the SEM images illustrated the increase in diameter and surface roughness of grafted silk compared with pure silk. Lastly, the dyeing performance of the modified silk was significantly increased.
文摘Characteristics and statistics of seismic tremors occurring during April 2015 were investigated by using short-period and broadband seismographs deployed at Syowa Station (SYO), in the Lützow-Holm Bay (LHB), East Antarctica. In order to examine a relationship between surface environments in particular cryosphere variation, the MODIS satellite images were utilized for comparison with the detected tremor events. Since a large volume of sea-ice was discharged during the April, together with several large icebergs passed through from the west to the east at northern edge of the fast sea-ice of LHB, it was expected to detect seismic tremors involving cryospehre dynamics. During the month, a total number of 49 tremor events including short duration ice shocks were identified. Majority of the events (N = 39) had their duration times more than 15 minutes, which were divided into both tremors and ice shocks on the basis of experienced definition at SYO. Cryospheric sources recorded by seismic tremors were classified into several origins (collision, calving, crevassing, crashing, etc.): “crevassing events” along the large cracks inside the fast sea-ice in LHB (04 April), “discharge events” of fast sea-ice from the Bay (07 April), “collision events” between iceberg and the edge of fast sea-ice (14 April), “crashing movement” between fragmentation of fast sea-ice and packed sea-ice (18 April), and other origins. In particular, strong amplitude tremors with harmonic overtones were assumed to be occurred independently from whether condition, because these overtone tremors were identified at less stormy days by comparison with infrasound data at SYO.
文摘Dye-sensitized titanium oxide electrodes were prepared by immobilizing a novel ruthenium complex, di(isothiocy- anato)bis(4-methyl-4’-vinyl-2,2’-bipyridine)ruthenium(II) [(NCS)2(mvbpy)2Ru(II)] or the ruthenium complex/sodium 4-vinylbenzenesulfonate onto the surface of a titanium oxide-coated, fluorine-doped tin oxide (TiO2/FTO) electrode through a new electrochemically initiated film formation method, in which the electrolysis step and the film deposition step were individually performed. The incident photon-to-current conversion efficiency (IPCE) of the Ru complex film on a TiO2/FTO electrode was disappointedly insufficient (1.2% at 440 nm). In sharp contrast, the Ru(II) complex/so- dium 4-vinylbenzenesulfonate composite film deposited on the surface of a TiO2/FTO electrode showed maximum IPCE of 31.7% at 438 nm.
基金This work was supported in part by the National Natural Science Foundation of China(61972174)the Science and Technology Planning Project of Guangdong Province(2020A0505100018)+1 种基金Guangdong Key-Project for Applied Fundamental Research(2018KZDXM076)Grants-in-Aid for Scientific Research(JP17K00312,JP17H03326)of Japan Society for the Promotion of Science(JSPS).
文摘The Keras deep learning framework is employed to study MRI brain data in a preliminary analysis of brain structure using a convolutional neural network.The results obtained are matched with the content of personality questionnaires.The Big Five personality traits provide easy differentiation for dividing personalities into different groups.Until now,the highest accuracy obtained from the results of personality prediction from the analysis of brain structure is about 70%.Although there is still no effective evidence to prove a clear relationship between brain structure and personality,the obtained results could prove helpful in understanding the basic relationship between brain structure and personality characteristics.
文摘Characteristic infrasound waves are clearly recorded at Syowa Station (SYO), East Antarctica, involving physical interaction in surrounding environments at the continent and SouthernOcean. A Chaparral microphone type infrasound sensor is deployed at SYO during the International Polar Year (IPY2007-2008), the most diverse international science program held recently. Continuous recorded data in 2008-2010 indicate a contamination of background oceanic signals (microbaroms). The characteristic signals are identified as the “microbaroms” with peaks between 4 and 10 s in the records. The peak amplitudes of microbaroms may be enhanced by the extratropical cyclonic storms and wind noises in Southern Ocean. The microbaroms has relatively lower amplitudes during austral winters, which may be caused by the larger amount of the sea-ice extent around theLützow-HolmBaynear SYO, with decreasing the ocean wave loading effects. In addition, the large energy with intrinsic periods between 12 and 30 s are observable under excellent storm conditions, particularly in local winter. The oceanic effects appearing on infrasound data are modulated by the presence of sea-ice and explained by a relationship between the atmosphere-ocean-cryosphere systems. Microbaroms measurements could be a useful tool for characterizing ocean wave climate, as well as a new proxy for monitoring a regional environmental variation inAntarctica.
