Chang'e-5(CE-5)mission is expected to land and sample in the Rümker region,north of the Oceanus Procellarum.To select optimal sampling points,the microwave radiation features in this mare unit are analyzed,an...Chang'e-5(CE-5)mission is expected to land and sample in the Rümker region,north of the Oceanus Procellarum.To select optimal sampling points,the microwave radiation features in this mare unit are analyzed,and the dielectric constant and thickness of lunar regolith are retrieved based on Chang'e lunar microwave sounder(CELMS)data.According to the microwave brightness temperature(TB)maps,TB varying with frequency at noon and midnight are different,in which noon TB increases with frequency,but midnight TB does not follow this rule.Moreover,there are differences among TB distributions at the three higher frequencies,especially in the southern part.In addition,a great TB difference between noon and midnight can be seen in Rümker E that shows higher daytime temperature but lower nighttime temperature.The inversion results reveal that the dielectric constant is lower in the west and north,higher in the middle and east,and the largest value occurs in Rümker E.As for the regolith thickness,most areas are uniform and no more than 4 m,with the thickest and thinnest regolith appearing in the northwest and Rümker E,no less than 6 m and about 2.5 m,respectively.Considering the safety and operability of landing and sampling,the northwest with thick regolith is recommended,while the Rümker E should be eluded.展开更多
针对钢板表面缺陷检测过程中出现的检测精度不高、小缺陷定位不准、误检率和漏检率高的问题,提出一种改进的快速区域卷积神经网络(faster region-based convolutional neural network,简称Faster R-CNN)算法.实验结果表明:相对于CNN(con...针对钢板表面缺陷检测过程中出现的检测精度不高、小缺陷定位不准、误检率和漏检率高的问题,提出一种改进的快速区域卷积神经网络(faster region-based convolutional neural network,简称Faster R-CNN)算法.实验结果表明:相对于CNN(convolutional neural network),YOLOv3(the third version of you only look once),SSD(single shot multibox detector)和YOLOv5(the fifth version of you only look once)算法,该文算法的检测平均精度均值最高、缺陷定位最准确、分类成功率最高.因此,该文算法具有有效性.展开更多
Studies on susceptibility to debris flows at regional scale(100-1000 km^2) are important for the protection and management of mountain areas. To reach this objective, routing models, mainly based on land topography, c...Studies on susceptibility to debris flows at regional scale(100-1000 km^2) are important for the protection and management of mountain areas. To reach this objective, routing models, mainly based on land topography, can be used to predict susceptible areas rapidly while necessitating few input data. In this research, Flow-R model is implemented to create the susceptibility map for the debris flow of the Vizze Valley(BZ, North-Eastern Italy; 134 km^2). The analysis considers the model application at local scale for three sub-catchments and then it explores the model upscaling at the regional scale by verifying two methods to generate the source areas of debris-flow initiation. Using data of an extreme event occurred in the Vizze Valley(4 August 2012) and historical information, the modeling verification highlights that the propagation parameters are relatively simple to set in order to obtain correct runout distances. A double DTM filtering-using a threshold for the upslope contributing area(0.1 km^2) and a threshold for the terrain-slope angle(15°)-provides a satisfactory prediction of source areas and susceptibility map within the geological conditions of the Vizze Valley.展开更多
Based on GISS-E2-R model simulations, the changes in PM2.5 and ozone concentrations during 2016– 35 are analyzed over the Jing-Jin-Ji region under different future emissions scenarios: 2.6, 4.5, 6.0, 8.5 Representati...Based on GISS-E2-R model simulations, the changes in PM2.5 and ozone concentrations during 2016– 35 are analyzed over the Jing-Jin-Ji region under different future emissions scenarios: 2.6, 4.5, 6.0, 8.5 Representative Concentration Pathways scenarios(RCP2.6, RCP4.5, RCP6.0, and RCP8.5), compared to the baseline periods of 1851–70(pre-industrial) and 1986–2005(present day). The results show that PM2.5 increases under all emissions scenarios, with the maximum value occurring in the southeastern part of the region under most scenarios. As for ozone, its concentration is projected to increase during 2016–35 under all emissions scenarios, compared to the baseline periods. The temporal evolutions of PM2.5 and ozone show PM2.5 reaching a peak during 2020–40, while ozone will likely increase steadily in the future.展开更多
AIM: To explore mutations around the interferon sensitivity-determining region (ISDR) which are associated with the resistance of hepatitis C virus 1b (HCV-1b) to interferon-α treatment. METHODS: Thirty-seven HCV-1b ...AIM: To explore mutations around the interferon sensitivity-determining region (ISDR) which are associated with the resistance of hepatitis C virus 1b (HCV-1b) to interferon-α treatment. METHODS: Thirty-seven HCV-1b samples were ob- tained from Hong Kong patients who had completed the combined interferon-α/ribavirin treatment for more than one year with available response data. Nineteen of them were sustained virological responders, while 18 were non-responders. The amino acid sequences of the extended ISDR (eISDR) covering 64 amino acids upstream and 67 amino acids downstream from the previously reported ISDR were analyzed. RESULTS: One amino acid variation (I2268V, P = 0.023) was significantly correlated with treatment outcomein this pilot study with a limited number of patients, while two amino acid variations (R2260H, P = 0.05 and S2278T, P = 0.05) were weakly associated with treatment outcome. The extent of amino acid variations within the ISDR or eISDR was not correlated with treatment outcome as previously reported. CONCLUSION: Three amino acid mutations near but outside of ISDR may associate with interferon treatment resistance of HCV-1b patients in Hong Kong.展开更多
文章基于改进更快的区域卷积神经网络(Faster Region Convolutional Neural Networks,Faster R-CNN)模型,提出了一种行人识别系统设计。介绍了计算机视觉常用技术手段与方法、通行检测步骤,分析了主流的算法优缺点,利用深度学习方法提...文章基于改进更快的区域卷积神经网络(Faster Region Convolutional Neural Networks,Faster R-CNN)模型,提出了一种行人识别系统设计。介绍了计算机视觉常用技术手段与方法、通行检测步骤,分析了主流的算法优缺点,利用深度学习方法提取图像特征,然后使用改进Faster R-CNN模型进行目标检测。在改进Faster R-CNN模型中,采用了自适应尺度池化和增强的感兴趣区域(Region of Interest,RoI)池化技术,可以提高模型检测精度和速度。展开更多
This paper shows the dynamic process of regional disparity of economic development in China in the past 50 years from a new insight by using the rescaled range statistic (R/S) analysis and wavelet analysis of the Thei...This paper shows the dynamic process of regional disparity of economic development in China in the past 50 years from a new insight by using the rescaled range statistic (R/S) analysis and wavelet analysis of the Theil index sequence with different time scales. The main conclusions are: 1) The regional disparity of economic development in China, including the inter-provincial disparity, inter-regional disparity and intra-regional disparity, has existed for many years. Theil index by the comparative price has revealed the true trend for comparative disparity of regional economic development from 1952 to 2000. 2) Decomposition of Theil index indicates that the dynamic trend of comparative inter-provincial disparity in the coastal region is in line with dynamic trend of inter-provincial disparity in the whole China. 3) The R/S analysis results tell us that during 1966-1978, the Hurst exponent H=0.504≈0.5, which indicates that in that period the evolution of comparative inter-provincial disparity of economic development showed a random characteristic, and in the other periods, i.e. 1952-1965, 1979-1990 and 1991-2000, the Hurst exponent H>0.5, which indicates that in those periods the evolution of the comparative inter-provincial disparity of economic development in China had a long-enduring characteristic. 4) By using wavelet analysis at different time scale, we arrived at a conclusion that the evolutionary process of the disparity of economic development of China is not a simple inverted U shape but a compound of several U shapes. The result tells us that the evolutionary plot of inter-provincial disparity in China follows the inverted U on the whole at the higher scale, 24(16 years). That is to say, the disparity tends to rise in the first stage of economic development, and fall slowly over the peak in the second stage of economic development. However, if we shorten the time scale to 23 (8 years), then a link of several U shapes will appear.展开更多
This paper presents a simple novel technique-forward gated-diode R-G current method-to determine the lateral lightly-doped source/drain (S/D) region interface state density and effective surface doping concentration o...This paper presents a simple novel technique-forward gated-diode R-G current method-to determine the lateral lightly-doped source/drain (S/D) region interface state density and effective surface doping concentration of the lightly-doped drain (LDD) N- MOSFET's simultaneously. One interesting result of the numerical analysis is the direct characterization of the interface state density and characteristic gate voltage values corresponding to LDD effective surface doping concentration. It is observed that the S/D N- surface doping concentration and corresponding region's interface state density are R-G current peak position and amplitude dependent, respectively. It is convincible that the proposed method is well suitable for the characterization of deep sub-micron MOSFET's in the current ULSI technology.展开更多
The Alpine region of Uvira District in South-Kivu Province faces low agricultural productivity challenges largely due to human population pressure on the natural resource base. During the dry season, conflicts between...The Alpine region of Uvira District in South-Kivu Province faces low agricultural productivity challenges largely due to human population pressure on the natural resource base. During the dry season, conflicts between crop farmers and livestock breeders are common. This region is located 2500 - 3020 m a.s.l. and is almost inaccessible due to poor road infrastructure. To understand the interactions between natural resources (forests, pastures, soils) and sedentary agriculture, and to propose solutions for sustainable natural resource management, Participatory Rural Appraisal (PRA) sessions covering three farmer group interviews were conducted in July 2010 in Marungu, Kitembe and Kahololo location. The livelihoods of the Banyamulenge have been transformed from pastoralism to a sedentary system with the introduction of crop cultivation after 1980. Maize, bush beans and Irish potatoes are cultivated with limited success because of late crop maturity under the prevailing climatic conditions. Livestock, mainly cattle, sheep and goats is managed under extensive system, relying on natural pasture far from the human settlements. Livestock plays an important role to define people’s wealth and is mainly managed by men. There is a real need of forages during the dry season;however, cultivation of forages is unknown. On the other hand, pastures appear to be degenerating due to overgrazing. Access by farmers to efficient and effective agricultural extension services is fundamental in order to promote locally adapted and profitable crop and livestock production while at the same time, sustaining the productive resource base and security.展开更多
One of the most commonly used equations to estimate soil erosion is the revised universal soil loss equation (RUSLE). Based on the early approach developed by the Soil Conservation Service of USA, the rainfall erosivi...One of the most commonly used equations to estimate soil erosion is the revised universal soil loss equation (RUSLE). Based on the early approach developed by the Soil Conservation Service of USA, the rainfall erosivity factor (R-factor) in the RUSLE equation requires sub-daily rainfall data, which is usually not available. Other empirical equations estimate R-factor based on available rainfall data like annual and monthly rainfall data. In arid regions such as the Arabian Peninsula, several studies estimated the R-factor based on these empirical equations without calibration. We propose in this paper to assess the applicability of some of these empirical equations against R-factor values calculated using as a reference the RUSLE approach. For this data, data from 104 stations with sub-daily rainfall was collected. The reference R-factor w<span><span><span style="font-family:;" "="">as</span></span></span><span><span><span style="font-family:;" "=""> calculated for the 104 stations. The results of seven empirical equations were tested against the reference R-factor. Most of the tested equations significantly underestimated the R-factor. Furthermore, the obtained RMSE and MAE values were almost as high as the average R-factor, with MAPE exceeding 100%. Therefore, it is recommended not to apply these equations in arid regions. A recalibration of the form of equation that gave the best results, gave a</span></span></span><span><span><span style="font-family:;" "="">n</span></span></span><span><span><span style="font-family:;" "=""> RMSE of 280 (Mj<span style="color:#4F4F4F;font-family:-apple-system, "font-size:16px;white-space:normal;background-color:#F7F7F7;">·</span>mm/(ha<span style="color:#4F4F4F;font-family:-apple-system, "font-size:16px;white-space:normal;background-color:#F7F7F7;">·</span>hr)) and the MAPE dropped to 47.6%.</span></span></span>展开更多
In this paper, according to the data on the middle and strong earthquakes in China, we have preliminary studied the relation between the characteristic of space-time evolution of the seismic apparent strain field and ...In this paper, according to the data on the middle and strong earthquakes in China, we have preliminary studied the relation between the characteristic of space-time evolution of the seismic apparent strain field and the regions of 31 macroseism events since 1955. The result shows that, there is a rather well correlation between the anomaly region of seismic apparent strain and the zone of macroseism event occurrence within the time range of one to about five years. The R value of the application of the abnormal region of seismic apparent strain to predicting the area of strong earthquake occurrence is 0.458, and the empirical possibility of forecasting the region of macroseism occurrence is 0.625, and so the forecasting effect is comparatively well. Finally, the main results obtained above are discussed preliminarily.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.41771405)。
文摘Chang'e-5(CE-5)mission is expected to land and sample in the Rümker region,north of the Oceanus Procellarum.To select optimal sampling points,the microwave radiation features in this mare unit are analyzed,and the dielectric constant and thickness of lunar regolith are retrieved based on Chang'e lunar microwave sounder(CELMS)data.According to the microwave brightness temperature(TB)maps,TB varying with frequency at noon and midnight are different,in which noon TB increases with frequency,but midnight TB does not follow this rule.Moreover,there are differences among TB distributions at the three higher frequencies,especially in the southern part.In addition,a great TB difference between noon and midnight can be seen in Rümker E that shows higher daytime temperature but lower nighttime temperature.The inversion results reveal that the dielectric constant is lower in the west and north,higher in the middle and east,and the largest value occurs in Rümker E.As for the regolith thickness,most areas are uniform and no more than 4 m,with the thickest and thinnest regolith appearing in the northwest and Rümker E,no less than 6 m and about 2.5 m,respectively.Considering the safety and operability of landing and sampling,the northwest with thick regolith is recommended,while the Rümker E should be eluded.
文摘针对钢板表面缺陷检测过程中出现的检测精度不高、小缺陷定位不准、误检率和漏检率高的问题,提出一种改进的快速区域卷积神经网络(faster region-based convolutional neural network,简称Faster R-CNN)算法.实验结果表明:相对于CNN(convolutional neural network),YOLOv3(the third version of you only look once),SSD(single shot multibox detector)和YOLOv5(the fifth version of you only look once)算法,该文算法的检测平均精度均值最高、缺陷定位最准确、分类成功率最高.因此,该文算法具有有效性.
基金granted by the Junior Research Grant Universitàdegli Studi di Padova,year 2013,prot.CPDR138494(“Criticitàidrauliche nel reticolo montano nei riguardi del movimento di detrito legnoso e di colate detritiche”Prof.Vincenzo D’Agostino)
文摘Studies on susceptibility to debris flows at regional scale(100-1000 km^2) are important for the protection and management of mountain areas. To reach this objective, routing models, mainly based on land topography, can be used to predict susceptible areas rapidly while necessitating few input data. In this research, Flow-R model is implemented to create the susceptibility map for the debris flow of the Vizze Valley(BZ, North-Eastern Italy; 134 km^2). The analysis considers the model application at local scale for three sub-catchments and then it explores the model upscaling at the regional scale by verifying two methods to generate the source areas of debris-flow initiation. Using data of an extreme event occurred in the Vizze Valley(4 August 2012) and historical information, the modeling verification highlights that the propagation parameters are relatively simple to set in order to obtain correct runout distances. A double DTM filtering-using a threshold for the upslope contributing area(0.1 km^2) and a threshold for the terrain-slope angle(15°)-provides a satisfactory prediction of source areas and susceptibility map within the geological conditions of the Vizze Valley.
基金support from the R&D Special Fund for Public Welfare Industry (Meteorology) (Grant No. GYHY201306019)the National Natural Science Foundation of China (Grant No. 41275078)+1 种基金the Grant Projects of China Clean Development Mechanism Fund (Grant No. 121312)the Climate Change Foundation of China Meteorological Administration (Grant No. CCSF201339)
文摘Based on GISS-E2-R model simulations, the changes in PM2.5 and ozone concentrations during 2016– 35 are analyzed over the Jing-Jin-Ji region under different future emissions scenarios: 2.6, 4.5, 6.0, 8.5 Representative Concentration Pathways scenarios(RCP2.6, RCP4.5, RCP6.0, and RCP8.5), compared to the baseline periods of 1851–70(pre-industrial) and 1986–2005(present day). The results show that PM2.5 increases under all emissions scenarios, with the maximum value occurring in the southeastern part of the region under most scenarios. As for ozone, its concentration is projected to increase during 2016–35 under all emissions scenarios, compared to the baseline periods. The temporal evolutions of PM2.5 and ozone show PM2.5 reaching a peak during 2020–40, while ozone will likely increase steadily in the future.
基金Supported by The National Key Technology Research and Development Program of China, No. 2009ZX10004-104
文摘AIM: To explore mutations around the interferon sensitivity-determining region (ISDR) which are associated with the resistance of hepatitis C virus 1b (HCV-1b) to interferon-α treatment. METHODS: Thirty-seven HCV-1b samples were ob- tained from Hong Kong patients who had completed the combined interferon-α/ribavirin treatment for more than one year with available response data. Nineteen of them were sustained virological responders, while 18 were non-responders. The amino acid sequences of the extended ISDR (eISDR) covering 64 amino acids upstream and 67 amino acids downstream from the previously reported ISDR were analyzed. RESULTS: One amino acid variation (I2268V, P = 0.023) was significantly correlated with treatment outcomein this pilot study with a limited number of patients, while two amino acid variations (R2260H, P = 0.05 and S2278T, P = 0.05) were weakly associated with treatment outcome. The extent of amino acid variations within the ISDR or eISDR was not correlated with treatment outcome as previously reported. CONCLUSION: Three amino acid mutations near but outside of ISDR may associate with interferon treatment resistance of HCV-1b patients in Hong Kong.
文摘文章基于改进更快的区域卷积神经网络(Faster Region Convolutional Neural Networks,Faster R-CNN)模型,提出了一种行人识别系统设计。介绍了计算机视觉常用技术手段与方法、通行检测步骤,分析了主流的算法优缺点,利用深度学习方法提取图像特征,然后使用改进Faster R-CNN模型进行目标检测。在改进Faster R-CNN模型中,采用了自适应尺度池化和增强的感兴趣区域(Region of Interest,RoI)池化技术,可以提高模型检测精度和速度。
基金Under the auspices of National Philosophy and Social Sciences Foundation of China (No. 00BJL051 03BJL027)
文摘This paper shows the dynamic process of regional disparity of economic development in China in the past 50 years from a new insight by using the rescaled range statistic (R/S) analysis and wavelet analysis of the Theil index sequence with different time scales. The main conclusions are: 1) The regional disparity of economic development in China, including the inter-provincial disparity, inter-regional disparity and intra-regional disparity, has existed for many years. Theil index by the comparative price has revealed the true trend for comparative disparity of regional economic development from 1952 to 2000. 2) Decomposition of Theil index indicates that the dynamic trend of comparative inter-provincial disparity in the coastal region is in line with dynamic trend of inter-provincial disparity in the whole China. 3) The R/S analysis results tell us that during 1966-1978, the Hurst exponent H=0.504≈0.5, which indicates that in that period the evolution of comparative inter-provincial disparity of economic development showed a random characteristic, and in the other periods, i.e. 1952-1965, 1979-1990 and 1991-2000, the Hurst exponent H>0.5, which indicates that in those periods the evolution of the comparative inter-provincial disparity of economic development in China had a long-enduring characteristic. 4) By using wavelet analysis at different time scale, we arrived at a conclusion that the evolutionary process of the disparity of economic development of China is not a simple inverted U shape but a compound of several U shapes. The result tells us that the evolutionary plot of inter-provincial disparity in China follows the inverted U on the whole at the higher scale, 24(16 years). That is to say, the disparity tends to rise in the first stage of economic development, and fall slowly over the peak in the second stage of economic development. However, if we shorten the time scale to 23 (8 years), then a link of several U shapes will appear.
基金Sponsored by Motorola CPTL(Contract No:MSPSDDLCHINA-0004)
文摘This paper presents a simple novel technique-forward gated-diode R-G current method-to determine the lateral lightly-doped source/drain (S/D) region interface state density and effective surface doping concentration of the lightly-doped drain (LDD) N- MOSFET's simultaneously. One interesting result of the numerical analysis is the direct characterization of the interface state density and characteristic gate voltage values corresponding to LDD effective surface doping concentration. It is observed that the S/D N- surface doping concentration and corresponding region's interface state density are R-G current peak position and amplitude dependent, respectively. It is convincible that the proposed method is well suitable for the characterization of deep sub-micron MOSFET's in the current ULSI technology.
文摘The Alpine region of Uvira District in South-Kivu Province faces low agricultural productivity challenges largely due to human population pressure on the natural resource base. During the dry season, conflicts between crop farmers and livestock breeders are common. This region is located 2500 - 3020 m a.s.l. and is almost inaccessible due to poor road infrastructure. To understand the interactions between natural resources (forests, pastures, soils) and sedentary agriculture, and to propose solutions for sustainable natural resource management, Participatory Rural Appraisal (PRA) sessions covering three farmer group interviews were conducted in July 2010 in Marungu, Kitembe and Kahololo location. The livelihoods of the Banyamulenge have been transformed from pastoralism to a sedentary system with the introduction of crop cultivation after 1980. Maize, bush beans and Irish potatoes are cultivated with limited success because of late crop maturity under the prevailing climatic conditions. Livestock, mainly cattle, sheep and goats is managed under extensive system, relying on natural pasture far from the human settlements. Livestock plays an important role to define people’s wealth and is mainly managed by men. There is a real need of forages during the dry season;however, cultivation of forages is unknown. On the other hand, pastures appear to be degenerating due to overgrazing. Access by farmers to efficient and effective agricultural extension services is fundamental in order to promote locally adapted and profitable crop and livestock production while at the same time, sustaining the productive resource base and security.
文摘One of the most commonly used equations to estimate soil erosion is the revised universal soil loss equation (RUSLE). Based on the early approach developed by the Soil Conservation Service of USA, the rainfall erosivity factor (R-factor) in the RUSLE equation requires sub-daily rainfall data, which is usually not available. Other empirical equations estimate R-factor based on available rainfall data like annual and monthly rainfall data. In arid regions such as the Arabian Peninsula, several studies estimated the R-factor based on these empirical equations without calibration. We propose in this paper to assess the applicability of some of these empirical equations against R-factor values calculated using as a reference the RUSLE approach. For this data, data from 104 stations with sub-daily rainfall was collected. The reference R-factor w<span><span><span style="font-family:;" "="">as</span></span></span><span><span><span style="font-family:;" "=""> calculated for the 104 stations. The results of seven empirical equations were tested against the reference R-factor. Most of the tested equations significantly underestimated the R-factor. Furthermore, the obtained RMSE and MAE values were almost as high as the average R-factor, with MAPE exceeding 100%. Therefore, it is recommended not to apply these equations in arid regions. A recalibration of the form of equation that gave the best results, gave a</span></span></span><span><span><span style="font-family:;" "="">n</span></span></span><span><span><span style="font-family:;" "=""> RMSE of 280 (Mj<span style="color:#4F4F4F;font-family:-apple-system, "font-size:16px;white-space:normal;background-color:#F7F7F7;">·</span>mm/(ha<span style="color:#4F4F4F;font-family:-apple-system, "font-size:16px;white-space:normal;background-color:#F7F7F7;">·</span>hr)) and the MAPE dropped to 47.6%.</span></span></span>
基金The Key Project(95-04-06-03,95-04-07-02)from China Seismological Bureau.
文摘In this paper, according to the data on the middle and strong earthquakes in China, we have preliminary studied the relation between the characteristic of space-time evolution of the seismic apparent strain field and the regions of 31 macroseism events since 1955. The result shows that, there is a rather well correlation between the anomaly region of seismic apparent strain and the zone of macroseism event occurrence within the time range of one to about five years. The R value of the application of the abnormal region of seismic apparent strain to predicting the area of strong earthquake occurrence is 0.458, and the empirical possibility of forecasting the region of macroseism occurrence is 0.625, and so the forecasting effect is comparatively well. Finally, the main results obtained above are discussed preliminarily.