A set of high resolution(25 km)21st century climate change projections using the regional climate model RegCM4 driven by four global model simulations were conducted over East Asia under the mid-range RCP4.5 scenario....A set of high resolution(25 km)21st century climate change projections using the regional climate model RegCM4 driven by four global model simulations were conducted over East Asia under the mid-range RCP4.5 scenario.In the present paper,the authors investigate the change in thermal comfort conditions over china based on an ensemble of the projections,using the index of effective temperature(ET),which considers the aggregate effects of temperature,relative humidity,and wind on human thermal perception.The analysis also accounts for exposure as measured by distributed population amount scenarios.The authors find that the general increase in ET leads to a large increase in population exposure to very hot days(a China-aggregated sixfold increase in‘person-days’by the end of the 21st century.There is a decrease in cool,cold,and very cold person-days.Meanwhile,a decrease in comfortable day conditions by 22%person-days is found despite an increase in climate-based comfortable days.Analysis of the different contributions to the changes(climate,population,and interactions between the two)show that climate effects play a more important role in the hot end of the thermal comfort categories,while the population effects tend to be dominant in the cold categories.Thus,overall,even a mid-level warming scenario is found to increase the thermal stress over China,although there is a strong geographical dependence.The inclusion of population exposure strongly modulates the climateonly signal,which highlights the need for including socioeconomic factors in the assessment of risks associated with climate change.展开更多
The prefrontal cortex (PFC) plays an important role in cognitive process related to executive function, but is also active during resting states. Quantifying prefrontal cortex activity during resting states provides a...The prefrontal cortex (PFC) plays an important role in cognitive process related to executive function, but is also active during resting states. Quantifying prefrontal cortex activity during resting states provides a baseline for interpreting task-induced brain activity. Researchers commonly use resting conditions where participants are prompted to stare at a screen (eyes open) or close their eyes (eyes closed). Are these two conditions equivalent representations of a baseline resting state? Further, does prefrontal cortex activity during these conditions change as a function of development? The aim of this study was to examine differences in prefrontal cortex activity between eyes open and eyes closed conditions during resting states in children and adults to provide a rationale of proper selection of baseline condition in future research. Thirty-six participants in 3 age groups were recruited in this study including twenty-four adults, five 12 - 15 years old children, and seven 8 - 11 years old children. Relative changes in concentrations of oxygenated hemoglobin (Δoxy-Hb) and deoxygenated hemoglobin (Δdeoxy-Hb) were obtained by using functional Near-Infrared Spectroscopy (fNIRS) in eyes closed (EC) and eyes open (EO) conditions, 3 minutes each. Contrasts were tested to compare the differences of Δoxy-Hb and Δdeoxy-Hb between eyes open and eyes closed conditions. The EC condition had significantly higher Δoxy-Hb than EO when all groups were combined (t (17.268) = 3.021, p = .008, Cohen’s d = –0.72). When comparing Δoxy-Hb between eyes conditions within each group, the younger group had significantly higher Δoxy-Hb in EC than EO (t (9.459) = 2.734, p = 0.022, Cohen’s d = –1.46). Based on these results, the EO condition may be a better baseline condition, particularly in studies with younger children, since it has less activity in the PFC that could interfere with interpretations of task-induced activity.展开更多
"Substantial" changes have taken place in China’s human rights conditions, according to Professor Xu Xianming, president of the China University of Law and Political Sciences. As a member of the Law Committ..."Substantial" changes have taken place in China’s human rights conditions, according to Professor Xu Xianming, president of the China University of Law and Political Sciences. As a member of the Law Committee of the Standing Committee of the National People’s Congress, China’s highest legislature, he is known for his contributions to improvements in the country’s legal system. In an interview with Human Rights magazine, Professor Xu Xianming listed what he chose to call the "five most important changes" in China’s human rights conditions:展开更多
After riots that occurred on March 14, 2008 in Lhasa, Tibet, the China Central Television Station broadcast a documentary film titled Tibet's Past shot years ago by the Central Newsreel & Documentary Film Studio abo...After riots that occurred on March 14, 2008 in Lhasa, Tibet, the China Central Television Station broadcast a documentary film titled Tibet's Past shot years ago by the Central Newsreel & Documentary Film Studio about the miserable life of serfs under Tibet's feudal serf system before a democratic reform was carried out in the region. The documentary stunned many people. It helps people see through the reactionary and corrupt nature of the Dalai clique.展开更多
It is well known that most Chinese nonEnglish majors can't understand the English materials they have heard,but they do understand them if the materials are in written form.Though there may be a lot of reasons (Su...It is well known that most Chinese nonEnglish majors can't understand the English materials they have heard,but they do understand them if the materials are in written form.Though there may be a lot of reasons (Such as phonological and psychological ones),this paper covers the influence of sound changes in connected speech upon the learners' listening comprehension.Non-English majors can improve their listening comprehension,to some degrees,by getting familiar with and being practiced in sound-changes in a flow of speech,with the help of a good attitude towards sound-changes in English speeches.展开更多
The response of a grassland ecosystem to climate change is discussed within the context of a theoretical model.An optimization approach,a conditional nonlinear optimal perturbation related to parameter(CNOP-P) appro...The response of a grassland ecosystem to climate change is discussed within the context of a theoretical model.An optimization approach,a conditional nonlinear optimal perturbation related to parameter(CNOP-P) approach,was employed in this study.The CNOP-P,a perturbation of moisture index in the theoretical model,represents a nonlinear climate perturbation.Two kinds of linear climate perturbations were also used to study the response of the grassland ecosystem to different types of climate changes.The results show that the extent of grassland ecosystem variation caused by the CNOP-P-type climate change is greater than that caused by the two linear types of climate change.In addition,the grassland ecosystem affected by the CNOP-P-type climate change evolved into a desert ecosystem,and the two linear types of climate changes failed within a specific amplitude range when the moisture index recovered to its reference state.Therefore,the grassland ecosystem response to climate change was nonlinear.This study yielded similar results for a desert ecosystem seeded with both living and wilted biomass litter.The quantitative analysis performed in this study also accounted for the role of soil moisture in the root zone and the shading effect of wilted biomass on the grassland ecosystem through nonlinear interactions between soil and vegetation.The results of this study imply that the CNOP-P approach is a potentially effective tool for assessing the impact of nonlinear climate change on grassland ecosystems.展开更多
This experiment aims to study the effects and modifications that occurred on acoustic signal harmonics when travelling through wood. The experiment measured the output amplitudes and frequencies of the travelling sign...This experiment aims to study the effects and modifications that occurred on acoustic signal harmonics when travelling through wood. The experiment measured the output amplitudes and frequencies of the travelling signals and compared them with the original input signal. The factors under investigation in this experiment included: wood type, wood moisture content (MC), input signal frequencies, signal travelling distance and wood condition (wood with/without cracks). The experiment findings demonstrated that higher input signal frequencies results in higher attenuation of acoustic emissions (AE) travelling through the wood. The results also indicate that: wood type, MC, the signal’s travelling distance, and the orientation of the travelling signal, compared to the wood’s grain direction, affected the signal propagation.展开更多
This paper presents a back-propagation neural network model for sound quality prediction (BPNN-SQP) of multiple working conditions’ vehicle interior noise. According to the standards and regulations, four kinds of ve...This paper presents a back-propagation neural network model for sound quality prediction (BPNN-SQP) of multiple working conditions’ vehicle interior noise. According to the standards and regulations, four kinds of vehicle interior noises under operating conditions, including idle, constant speed, accelerating and braking, are acquired. The objective psychoacoustic parameters and subjective annoyance results are respectively used as the input and output of the BPNN-SQP model. With correlation analysis and significance test, some psychoacoustic parameters, such as loudness, A-weighted sound pressure level, roughness, articulation index and sharpness, are selected for modeling. The annoyance values of unknown noise samples estimated by the BPNN-SQP model are highly correlated with the subjective annoyances. Conclusion can be drawn that the proposed BPNN-SQP model has good generalization ability and can be applied in sound quality prediction of vehicle interior noise under multiple working conditions.展开更多
More and more attention was paid to phase change energy storage in air conditioning domain and construction energy conservation,and became the focus of the international research. Through the test and analysis of the ...More and more attention was paid to phase change energy storage in air conditioning domain and construction energy conservation,and became the focus of the international research. Through the test and analysis of the parameters of the indoor thermal property in phase change wallboard room and ordinary room,the effects of using phase change wallboards on indoor temperature in summer and air conditioning are obtained. The combination of construct enclosure and phase change materials can stabilize indoor temperature,improve indoor thermal comfort,reduce the frequency of the operation of air conditioning facility,cut the initial investment and operation expense,and meanwhile play an practical role in "the power balancing between the peak period and the valley period" policy. Through the experiment and the test of the effects exerted by phase change wallboard room and ordinary room on the indoor thermal environment,it is obtained that the phase change wallboard can reduce the fluctuation range of indoor temperature and the heat flow from the outside into indoor environment in summer. According to the study,it is found that the effect of cool-storing for 5 h is obvious. Through the analysis of the phase change wallboard without air conditioning in daytime,it is obtained that the frequency of the operation of air conditioning in phase change wallboard room is smaller than that in the ordinary room,which can prolong the lifetime of the facility and reduce operation expense.展开更多
Objective To investigate the protective effects of sound conditioning against subsequent high -level noise trauma in rats.Method Rats were exposed to a 4 kHz octave band noise at 95 dB SPL for 10 hours,then to a traum...Objective To investigate the protective effects of sound conditioning against subsequent high -level noise trauma in rats.Method Rats were exposed to a 4 kHz octave band noise at 95 dB SPL for 10 hours,then to a traumatic exposure dose(105 dB SPL for 13 hours) delivered 12h later.Control animals were exposured to the traumatic dose only.ABR thresholds were obtained before and after noise exposure.Result Animals that had been sound conditioned demonstrated less ABR threshold shift compared to those that had not.Conclusion Moderate level sound exposure appears to have a toughening effect on the rat cochlea(or'conditioning') leading to decreased hearing loss from subsequent traumatic exposure.展开更多
In this paper,we establish a new algorithm to the non-overlapping Schwarz domain decomposition methods with changing transmission conditions for solving one dimensional advection reaction diffusion problem.More precis...In this paper,we establish a new algorithm to the non-overlapping Schwarz domain decomposition methods with changing transmission conditions for solving one dimensional advection reaction diffusion problem.More precisely,we first describe the new algorithm and prove the convergence results under several natural assumptions on the sequences of parameters which determine the transmission conditions.Then we give a simple method to estimate the new value of parameters in each iteration.The interesting advantage of our method is that one may update the better parameters in each iteration to save the computational cost for optimizing the parameters after many steps.Finally some numerical experiments are performed to show the behavior of the convergence rate for the new method.展开更多
Trend and climate change were studied in annual rainfall data for the period of 62 years (1949-2010) of Sagar and 65 years (1945-2010) of Damoh districts of Bundelkhand region of central India. The analysis of weekly ...Trend and climate change were studied in annual rainfall data for the period of 62 years (1949-2010) of Sagar and 65 years (1945-2010) of Damoh districts of Bundelkhand region of central India. The analysis of weekly rainfall probability was also carried out at both the locations for field operations and crop planning in rainfed agricultural system for improving the farmer’s livelihood. Mean annual rainfall was 1233.8 mm with 32.6% variability for Sagar and 1225.1 mm with 30.3% variability for Damoh region. Sagar and Damoh region exhibited significant decreasing trend in the total amount of annual rainfall in the last 15 years (1996 to 2010). Also, both locations showed significant long-term decreasing trend in annual rainfall. Climate of both the regions have changed as in the recent 15 years annual rainfall had decreased by 156.4 and 310.7 mm at Sagar and Damoh from their long period average (LPA), respectively. The Initial and conditional rainfall probability analysis at Damoh reinforced that Initial probabilities {P (W)} of getting 10 mm rainfall per week was 76% during 25th (18-24 June) SMW. Thus, the seed bed preparation could be initiated during this week. Initial as well as conditional probability of wet week followed by wet week {P(W/W} of getting 20 mm rainfall was more than 80% during 27th SMW (2-7 July) in Sagar district. Therefore, this week is most suitable for sowing operation in this district.展开更多
The effect of global climate change on vegetation growth is variable.Timely and effective monitoring of vegetation drought is crucial for understanding its dynamics and mitigation,and even regional protection of ecolo...The effect of global climate change on vegetation growth is variable.Timely and effective monitoring of vegetation drought is crucial for understanding its dynamics and mitigation,and even regional protection of ecological environments.In this study,we constructed a new drought index(i.e.,Vegetation Drought Condition Index(VDCI))based on precipitation,potential evapotranspiration,soil moisture and Normalized Difference Vegetation Index(NDVI)data,to monitor vegetation drought in the nine major river basins(including the Songhua River and Liaohe River Basin,Haihe River Basin,Yellow River Basin,Huaihe River Basin,Yangtze River Basin,Southeast River Basin,Pearl River Basin,Southwest River Basin and Continental River Basin)in China at 1-month–12-month(T1–T12)time scales.We used the Pearson's correlation coefficients to assess the relationships between the drought indices(the developed VDCI and traditional drought indices including the Standardized Precipitation Evapotranspiration Index(SPEI),Standardized Soil Moisture Index(SSMI)and Self-calibrating Palmer Drought Severity Index(scPDSI))and the NDVI at T1–T12 time scales,and to estimate and compare the lag times of vegetation response to drought among different drought indices.The results showed that precipitation and potential evapotranspiration have positive and major influences on vegetation in the nine major river basins at T1–T6 time scales.Soil moisture shows a lower degree of negative influence on vegetation in different river basins at multiple time scales.Potential evapotranspiration shows a higher degree of positive influence on vegetation,and it acts as the primary influencing factor with higher area proportion at multiple time scales in different river basins.The VDCI has a stronger relationship with the NDVI in the Songhua River and Liaohe River Basin,Haihe River Basin,Yellow River Basin,Huaihe River Basin and Yangtze River Basin at T1–T4 time scales.In general,the VDCI is more sensitive(with shorter lag time of vegetation response to drought)than the traditional drought indices(SPEI,scPDSI and SSMI)in monitoring vegetation drought,and thus it could be applied to monitor short-term vegetation drought.The VDCI developed in the study can reveal the law of unclear mechanisms between vegetation and climate,and can be applied in other fields of vegetation drought monitoring with complex mechanisms.展开更多
The major enrichment type of shale oil in the Chang 7_(3) shale of Upper Triassic Yanchang Formation in the Ordos Basin is unknown.This paper analyzes the organic matter transformation ratio,hydrocarbon expulsion effi...The major enrichment type of shale oil in the Chang 7_(3) shale of Upper Triassic Yanchang Formation in the Ordos Basin is unknown.This paper analyzes the organic matter transformation ratio,hydrocarbon expulsion efficiency and roof/floor sealing conditions of the Chang 7_(3) shale,and evaluates the major enrichment type of shale oil in this interval.The average organic matter transformation ratio of the Chang 7_(3) shale is about 45%;in other words,more than 50%of the organic matters have not transformed to hydrocarbons,and the lower the maturity,the greater the proportion of untransformed organic matters.The cumulative hydrocarbon expulsion efficiency of the transformed hydrocarbon is 27.5% on average,and the total proportion of untransformed organic matters plus retained hydrocarbons is greater than 70%.The relative hydrocarbon expulsion efficiency of the Chang 7_(3) shale is 60%on average,that is,about 40% of hydrocarbons retain in the shale.The Chang 7_(3) shale corresponds to Chang 7_(1+2) and Chang 8 sandstones as the roof and floor,respectively,and is further overlaid by Chang 6 shale,where extensive low porosity and low permeability–tight oil reservoirs have formed in the parts with relatively good porosity and permeability.Moreover,the Chang 7_(3) shale is tested to be in a negative pressure system(the pressure coefficient of 0.80–0.85).Therefore,the roof/floor sealing conditions of the Chang 7_(3) shale are poor.The retained hydrocarbons appear mostly in absorbed status,with low mobility.It is concluded that the medium–high mature shale oil is not the major enrichment type of shale oil in the Chang 7_(3) shale,but there may be enrichment opportunity for shale oil with good mobility in the areas where the sealing conditions are good without faults and fractures and oil reservoirs are formed off Chang 7_(1+2),Chang 6 and Chang 8.Furthermore,low–medium mature shale oil is believed to have great potential and is the major enrichment type of shale oil in the Chang 7_(3) shale.It is recommended to prepare relevant in-situ conversion technologies by pilot test and figure out the resource availability and distribution.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2016YFA0600704)the National Natural Science Foundation of China(Grant No.41375104)
文摘A set of high resolution(25 km)21st century climate change projections using the regional climate model RegCM4 driven by four global model simulations were conducted over East Asia under the mid-range RCP4.5 scenario.In the present paper,the authors investigate the change in thermal comfort conditions over china based on an ensemble of the projections,using the index of effective temperature(ET),which considers the aggregate effects of temperature,relative humidity,and wind on human thermal perception.The analysis also accounts for exposure as measured by distributed population amount scenarios.The authors find that the general increase in ET leads to a large increase in population exposure to very hot days(a China-aggregated sixfold increase in‘person-days’by the end of the 21st century.There is a decrease in cool,cold,and very cold person-days.Meanwhile,a decrease in comfortable day conditions by 22%person-days is found despite an increase in climate-based comfortable days.Analysis of the different contributions to the changes(climate,population,and interactions between the two)show that climate effects play a more important role in the hot end of the thermal comfort categories,while the population effects tend to be dominant in the cold categories.Thus,overall,even a mid-level warming scenario is found to increase the thermal stress over China,although there is a strong geographical dependence.The inclusion of population exposure strongly modulates the climateonly signal,which highlights the need for including socioeconomic factors in the assessment of risks associated with climate change.
文摘The prefrontal cortex (PFC) plays an important role in cognitive process related to executive function, but is also active during resting states. Quantifying prefrontal cortex activity during resting states provides a baseline for interpreting task-induced brain activity. Researchers commonly use resting conditions where participants are prompted to stare at a screen (eyes open) or close their eyes (eyes closed). Are these two conditions equivalent representations of a baseline resting state? Further, does prefrontal cortex activity during these conditions change as a function of development? The aim of this study was to examine differences in prefrontal cortex activity between eyes open and eyes closed conditions during resting states in children and adults to provide a rationale of proper selection of baseline condition in future research. Thirty-six participants in 3 age groups were recruited in this study including twenty-four adults, five 12 - 15 years old children, and seven 8 - 11 years old children. Relative changes in concentrations of oxygenated hemoglobin (Δoxy-Hb) and deoxygenated hemoglobin (Δdeoxy-Hb) were obtained by using functional Near-Infrared Spectroscopy (fNIRS) in eyes closed (EC) and eyes open (EO) conditions, 3 minutes each. Contrasts were tested to compare the differences of Δoxy-Hb and Δdeoxy-Hb between eyes open and eyes closed conditions. The EC condition had significantly higher Δoxy-Hb than EO when all groups were combined (t (17.268) = 3.021, p = .008, Cohen’s d = –0.72). When comparing Δoxy-Hb between eyes conditions within each group, the younger group had significantly higher Δoxy-Hb in EC than EO (t (9.459) = 2.734, p = 0.022, Cohen’s d = –1.46). Based on these results, the EO condition may be a better baseline condition, particularly in studies with younger children, since it has less activity in the PFC that could interfere with interpretations of task-induced activity.
文摘"Substantial" changes have taken place in China’s human rights conditions, according to Professor Xu Xianming, president of the China University of Law and Political Sciences. As a member of the Law Committee of the Standing Committee of the National People’s Congress, China’s highest legislature, he is known for his contributions to improvements in the country’s legal system. In an interview with Human Rights magazine, Professor Xu Xianming listed what he chose to call the "five most important changes" in China’s human rights conditions:
文摘After riots that occurred on March 14, 2008 in Lhasa, Tibet, the China Central Television Station broadcast a documentary film titled Tibet's Past shot years ago by the Central Newsreel & Documentary Film Studio about the miserable life of serfs under Tibet's feudal serf system before a democratic reform was carried out in the region. The documentary stunned many people. It helps people see through the reactionary and corrupt nature of the Dalai clique.
文摘It is well known that most Chinese nonEnglish majors can't understand the English materials they have heard,but they do understand them if the materials are in written form.Though there may be a lot of reasons (Such as phonological and psychological ones),this paper covers the influence of sound changes in connected speech upon the learners' listening comprehension.Non-English majors can improve their listening comprehension,to some degrees,by getting familiar with and being practiced in sound-changes in a flow of speech,with the help of a good attitude towards sound-changes in English speeches.
基金supported by National Natural Science Foundation of China(Grant Nos. 40905050,40805020,40830955)the Chinese Academy of Sciences (Grants No. KZCX3-SW-230),LASG Free Exploration Fund,and LASG State Key Lab-oratory Special Fund
文摘The response of a grassland ecosystem to climate change is discussed within the context of a theoretical model.An optimization approach,a conditional nonlinear optimal perturbation related to parameter(CNOP-P) approach,was employed in this study.The CNOP-P,a perturbation of moisture index in the theoretical model,represents a nonlinear climate perturbation.Two kinds of linear climate perturbations were also used to study the response of the grassland ecosystem to different types of climate changes.The results show that the extent of grassland ecosystem variation caused by the CNOP-P-type climate change is greater than that caused by the two linear types of climate change.In addition,the grassland ecosystem affected by the CNOP-P-type climate change evolved into a desert ecosystem,and the two linear types of climate changes failed within a specific amplitude range when the moisture index recovered to its reference state.Therefore,the grassland ecosystem response to climate change was nonlinear.This study yielded similar results for a desert ecosystem seeded with both living and wilted biomass litter.The quantitative analysis performed in this study also accounted for the role of soil moisture in the root zone and the shading effect of wilted biomass on the grassland ecosystem through nonlinear interactions between soil and vegetation.The results of this study imply that the CNOP-P approach is a potentially effective tool for assessing the impact of nonlinear climate change on grassland ecosystems.
文摘This experiment aims to study the effects and modifications that occurred on acoustic signal harmonics when travelling through wood. The experiment measured the output amplitudes and frequencies of the travelling signals and compared them with the original input signal. The factors under investigation in this experiment included: wood type, wood moisture content (MC), input signal frequencies, signal travelling distance and wood condition (wood with/without cracks). The experiment findings demonstrated that higher input signal frequencies results in higher attenuation of acoustic emissions (AE) travelling through the wood. The results also indicate that: wood type, MC, the signal’s travelling distance, and the orientation of the travelling signal, compared to the wood’s grain direction, affected the signal propagation.
文摘This paper presents a back-propagation neural network model for sound quality prediction (BPNN-SQP) of multiple working conditions’ vehicle interior noise. According to the standards and regulations, four kinds of vehicle interior noises under operating conditions, including idle, constant speed, accelerating and braking, are acquired. The objective psychoacoustic parameters and subjective annoyance results are respectively used as the input and output of the BPNN-SQP model. With correlation analysis and significance test, some psychoacoustic parameters, such as loudness, A-weighted sound pressure level, roughness, articulation index and sharpness, are selected for modeling. The annoyance values of unknown noise samples estimated by the BPNN-SQP model are highly correlated with the subjective annoyances. Conclusion can be drawn that the proposed BPNN-SQP model has good generalization ability and can be applied in sound quality prediction of vehicle interior noise under multiple working conditions.
基金Project(50878133) supported by the National Natural Science Foundation of ChinaProject(2007R37) supported by the Program Supporting Excellent Talents of Liaoning Province,China+1 种基金Project(2008S193) supported by the Key Laboratory Fund of Education Department of Liaoning Province,ChinaProject(1071211-1-00) supported by the Scientific and Technical Fund Project Subsidy of Shenyang,China
文摘More and more attention was paid to phase change energy storage in air conditioning domain and construction energy conservation,and became the focus of the international research. Through the test and analysis of the parameters of the indoor thermal property in phase change wallboard room and ordinary room,the effects of using phase change wallboards on indoor temperature in summer and air conditioning are obtained. The combination of construct enclosure and phase change materials can stabilize indoor temperature,improve indoor thermal comfort,reduce the frequency of the operation of air conditioning facility,cut the initial investment and operation expense,and meanwhile play an practical role in "the power balancing between the peak period and the valley period" policy. Through the experiment and the test of the effects exerted by phase change wallboard room and ordinary room on the indoor thermal environment,it is obtained that the phase change wallboard can reduce the fluctuation range of indoor temperature and the heat flow from the outside into indoor environment in summer. According to the study,it is found that the effect of cool-storing for 5 h is obvious. Through the analysis of the phase change wallboard without air conditioning in daytime,it is obtained that the frequency of the operation of air conditioning in phase change wallboard room is smaller than that in the ordinary room,which can prolong the lifetime of the facility and reduce operation expense.
文摘Objective To investigate the protective effects of sound conditioning against subsequent high -level noise trauma in rats.Method Rats were exposed to a 4 kHz octave band noise at 95 dB SPL for 10 hours,then to a traumatic exposure dose(105 dB SPL for 13 hours) delivered 12h later.Control animals were exposured to the traumatic dose only.ABR thresholds were obtained before and after noise exposure.Result Animals that had been sound conditioned demonstrated less ABR threshold shift compared to those that had not.Conclusion Moderate level sound exposure appears to have a toughening effect on the rat cochlea(or'conditioning') leading to decreased hearing loss from subsequent traumatic exposure.
文摘In this paper,we establish a new algorithm to the non-overlapping Schwarz domain decomposition methods with changing transmission conditions for solving one dimensional advection reaction diffusion problem.More precisely,we first describe the new algorithm and prove the convergence results under several natural assumptions on the sequences of parameters which determine the transmission conditions.Then we give a simple method to estimate the new value of parameters in each iteration.The interesting advantage of our method is that one may update the better parameters in each iteration to save the computational cost for optimizing the parameters after many steps.Finally some numerical experiments are performed to show the behavior of the convergence rate for the new method.
文摘Trend and climate change were studied in annual rainfall data for the period of 62 years (1949-2010) of Sagar and 65 years (1945-2010) of Damoh districts of Bundelkhand region of central India. The analysis of weekly rainfall probability was also carried out at both the locations for field operations and crop planning in rainfed agricultural system for improving the farmer’s livelihood. Mean annual rainfall was 1233.8 mm with 32.6% variability for Sagar and 1225.1 mm with 30.3% variability for Damoh region. Sagar and Damoh region exhibited significant decreasing trend in the total amount of annual rainfall in the last 15 years (1996 to 2010). Also, both locations showed significant long-term decreasing trend in annual rainfall. Climate of both the regions have changed as in the recent 15 years annual rainfall had decreased by 156.4 and 310.7 mm at Sagar and Damoh from their long period average (LPA), respectively. The Initial and conditional rainfall probability analysis at Damoh reinforced that Initial probabilities {P (W)} of getting 10 mm rainfall per week was 76% during 25th (18-24 June) SMW. Thus, the seed bed preparation could be initiated during this week. Initial as well as conditional probability of wet week followed by wet week {P(W/W} of getting 20 mm rainfall was more than 80% during 27th SMW (2-7 July) in Sagar district. Therefore, this week is most suitable for sowing operation in this district.
基金funded by the National Natural Science Foundation of China(52179015,42301024)the Key Technologies Research&Development and Promotion Program of Henan(232102110025)the Cultivation Plan of Innovative Scientific and Technological Team of Water Conservancy Engineering Discipline of North China University of Water Resources and Electric Power(CXTDPY-9).
文摘The effect of global climate change on vegetation growth is variable.Timely and effective monitoring of vegetation drought is crucial for understanding its dynamics and mitigation,and even regional protection of ecological environments.In this study,we constructed a new drought index(i.e.,Vegetation Drought Condition Index(VDCI))based on precipitation,potential evapotranspiration,soil moisture and Normalized Difference Vegetation Index(NDVI)data,to monitor vegetation drought in the nine major river basins(including the Songhua River and Liaohe River Basin,Haihe River Basin,Yellow River Basin,Huaihe River Basin,Yangtze River Basin,Southeast River Basin,Pearl River Basin,Southwest River Basin and Continental River Basin)in China at 1-month–12-month(T1–T12)time scales.We used the Pearson's correlation coefficients to assess the relationships between the drought indices(the developed VDCI and traditional drought indices including the Standardized Precipitation Evapotranspiration Index(SPEI),Standardized Soil Moisture Index(SSMI)and Self-calibrating Palmer Drought Severity Index(scPDSI))and the NDVI at T1–T12 time scales,and to estimate and compare the lag times of vegetation response to drought among different drought indices.The results showed that precipitation and potential evapotranspiration have positive and major influences on vegetation in the nine major river basins at T1–T6 time scales.Soil moisture shows a lower degree of negative influence on vegetation in different river basins at multiple time scales.Potential evapotranspiration shows a higher degree of positive influence on vegetation,and it acts as the primary influencing factor with higher area proportion at multiple time scales in different river basins.The VDCI has a stronger relationship with the NDVI in the Songhua River and Liaohe River Basin,Haihe River Basin,Yellow River Basin,Huaihe River Basin and Yangtze River Basin at T1–T4 time scales.In general,the VDCI is more sensitive(with shorter lag time of vegetation response to drought)than the traditional drought indices(SPEI,scPDSI and SSMI)in monitoring vegetation drought,and thus it could be applied to monitor short-term vegetation drought.The VDCI developed in the study can reveal the law of unclear mechanisms between vegetation and climate,and can be applied in other fields of vegetation drought monitoring with complex mechanisms.
基金Supported by the National Natural Science Foundation of China(U22B6004).
文摘The major enrichment type of shale oil in the Chang 7_(3) shale of Upper Triassic Yanchang Formation in the Ordos Basin is unknown.This paper analyzes the organic matter transformation ratio,hydrocarbon expulsion efficiency and roof/floor sealing conditions of the Chang 7_(3) shale,and evaluates the major enrichment type of shale oil in this interval.The average organic matter transformation ratio of the Chang 7_(3) shale is about 45%;in other words,more than 50%of the organic matters have not transformed to hydrocarbons,and the lower the maturity,the greater the proportion of untransformed organic matters.The cumulative hydrocarbon expulsion efficiency of the transformed hydrocarbon is 27.5% on average,and the total proportion of untransformed organic matters plus retained hydrocarbons is greater than 70%.The relative hydrocarbon expulsion efficiency of the Chang 7_(3) shale is 60%on average,that is,about 40% of hydrocarbons retain in the shale.The Chang 7_(3) shale corresponds to Chang 7_(1+2) and Chang 8 sandstones as the roof and floor,respectively,and is further overlaid by Chang 6 shale,where extensive low porosity and low permeability–tight oil reservoirs have formed in the parts with relatively good porosity and permeability.Moreover,the Chang 7_(3) shale is tested to be in a negative pressure system(the pressure coefficient of 0.80–0.85).Therefore,the roof/floor sealing conditions of the Chang 7_(3) shale are poor.The retained hydrocarbons appear mostly in absorbed status,with low mobility.It is concluded that the medium–high mature shale oil is not the major enrichment type of shale oil in the Chang 7_(3) shale,but there may be enrichment opportunity for shale oil with good mobility in the areas where the sealing conditions are good without faults and fractures and oil reservoirs are formed off Chang 7_(1+2),Chang 6 and Chang 8.Furthermore,low–medium mature shale oil is believed to have great potential and is the major enrichment type of shale oil in the Chang 7_(3) shale.It is recommended to prepare relevant in-situ conversion technologies by pilot test and figure out the resource availability and distribution.