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Climate state of the Three Gorges Region in the Yangtze River basin in 2022–2023
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作者 Tong Cui Xianyan Chen +3 位作者 Xukai Zou Linhai Sun Qiang Zhang Hongling Zeng 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第5期61-66,共6页
Based on daily observation data of the Three Gorges Region(TGR)of the Yangtze River basin and global reanalysis data,the climate characteristics,climate events,and meteorological disasters of the TGR in 2022 and 2023 ... Based on daily observation data of the Three Gorges Region(TGR)of the Yangtze River basin and global reanalysis data,the climate characteristics,climate events,and meteorological disasters of the TGR in 2022 and 2023 were analyzed.For the TGR,the average annual temperature for 2022 and 2023 was 0.8℃ and 0.4℃ higher than normal,respectively,making them the two warmest years in the past decade.In 2022,the TGR experienced its warmest summer on record.The average air temperature was 2.4℃ higher than the average,and there were 24.8 days of above-average high temperature days during summer.Rainfall in the TGR varied significantly between 2022 and 2023.Annual rainfall was 18.4%below normal and drier than normal in most parts of the region.In contrast,the precipitation in 2023 was considerably higher than the long-term average,and above normal for almost the entire year.The average wind speed exhibited minimal variation between the two years.However,the number of foggy days and relative humidity increased in 2023 compared to 2022.In 2022–2023,the TGR mainly experienced meteorological disasters such as extreme high temperatures,regional heavy rain and flooding,overcast rain,and inverted spring chill.Analysis indicates that the abnormal western Pacific subtropical high and the abnormal persistence of the eastward-shifted South Asian high were the two important drivers of the durative enhancement of record-breaking high temperature in the summer of 2022. 展开更多
关键词 Three Gorges region Climate state Extreme high temperature Torrential summer rainfall Climate analysis
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Novel and favorable genomic regions for spike related traits in a wheat germplasm Pubing 3504 with high grain number per spike under varying environments 被引量:5
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作者 CHEN Dan WU Xiao-yang +6 位作者 WU Kuo ZHANG Jin-peng LIU Wei-hua YANG Xin-ming LI Xiu-quan LU Yu-qing LI Li-hui 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2017年第11期2386-2401,共16页
Grain number per spike (GNPS) is a major factor in wheat yield breeding. A new wheat germplasm Pubing 3504 shows superior features in spike traits. To elucidate the genetic basis of spike and yield related traits in... Grain number per spike (GNPS) is a major factor in wheat yield breeding. A new wheat germplasm Pubing 3504 shows superior features in spike traits. To elucidate the genetic basis of spike and yield related traits in Pubing 3504, 282 F2:3 families were generated from the cross Pubing 3504xJing 4839, and seven spike and yield related traits, including GNPS, spike length (SL), kernel number per spikelet (KPS), spikelet number per spike (SNS), thousand-grain weight (TGW), spike number per plant (SNP), and plant height (HT) were investigated. Correlation analysis indicated significant positive correlations between GNPS and spike-related traits, including KPS, SNS, and SL, especially KPS. A genetic map was constructed using 190 polymorphic simple sequence repeat (SSR), expressed sequence tag (EST)-SSR, and sequence- tagged-site (STS) markers. For the seven traits measured, a total of 37 quantitative trait loci (QTLs) in a single-environment analysis and 25 QTLs in a joint-environment analysis were detected. Additive effects of 70.3% (in a single environment) and 57.6% (in a joint environment) of the QTLs were positively contributed by Pubing 3504 alleles. Five important genomic regions on chromosomes 1A, 4A, 4B, 2D, and 4D could be stably detected in different environments. Among these regions, the marker interval Xmag834-Xbarc83 on the short arm of chromosome 1A was a novel important genomic region that included QTLs controlling GNPS, KPS, SNS, TGW, and SNP with stable environmental repeatability. This genomic region can improve the spike trait and may play a key role in improving wheat yield in the future. We deduced that this genomic region was vital to the high GNPS of Pubing 3504. 展开更多
关键词 WHEAT high GNPS germplasm QTL mapping genomic region
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Characteristics of highly differentiated granite and metallization of tungsten-tin, rare and rare earth metal in the eastern Nanling region, China 被引量:6
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作者 XIAO Huiliang CHEN Lezhu +5 位作者 FAN Feipeng LI Haili BAO Xiaoming YAO Zhenghong ZHOU Yan CAI Yitao 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第S1期100-101,共2页
1 Introduction Massive tungsten-tin,rare and rare earth metals ore deposits were formed with the widespread granite magmatic activity in early Yanshanian period in the eastern Nanling region.Recent studies indicate th... 1 Introduction Massive tungsten-tin,rare and rare earth metals ore deposits were formed with the widespread granite magmatic activity in early Yanshanian period in the eastern Nanling region.Recent studies indicate that the Yanshanian highly differentiated-granite formation is closely related to the deposits of tungsten and tin,rare and rare earth metals mineralization in the region(Xiao 展开更多
关键词 Th high rare and rare earth metal in the eastern Nanling region Characteristics of highly differentiated granite and metallization of tungsten-tin China
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Influences of Seasonal Freezing and Thawing on Soil Water-stable Aggregates in Orchard in High Cold Region,Northeast China 被引量:3
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作者 LIANG Yunjiang DENG Xu +4 位作者 SONG Tao CHEN Guoshuang WANG Yuemei ZHANG Qing LU Xinrui 《Chinese Geographical Science》 SCIE CSCD 2021年第2期234-247,共14页
Soil aggregate stability,as an important indicator of soil functions,may be affected by seasonal freezing and thawing(SFT)and land use in high cold and wet regions.Therefore,comprehensive understanding the effects of ... Soil aggregate stability,as an important indicator of soil functions,may be affected by seasonal freezing and thawing(SFT)and land use in high cold and wet regions.Therefore,comprehensive understanding the effects of SFT on aggregate stability in orchards during winter and spring is crucial to develop appropriate management strategies that can effectively alleviate the degradation of soil quality to ensure sustainable development of orchard ecosystems.To determine the mechanism of degradation in orchard soil quality,the effects of SFT on the stability of water-stable aggregates were examined in apple-pear orchards(Pyrus ussuriensis var.ovoidea)of four different ages(11,25,40,and 63 yr)on 0 to 5%slopes before freezing and after thawing from October 2015 to June 2016 in Longjing City,Yanbian Prefecture,Northeast China,involving a comparison of planted versus adjacent uncultivated lands(control).Soil samples were collected to investigate water-stable aggregate stability in three incremental soil layers(0–20,20–40 and 40–60 cm).In the same samples,iron oxide,organic matter,and clay contents of the soil were also determined.Results showed that the destructive influences of SFT on water-stable aggregates were more pronounced with the increased orchards ages,and SFT exerted severe effects on water-stable aggregates of older orchards(40 and 63 yr)than juvenile orchards.Undergoing SFT,the soil instability index and the percentage of aggregate destruction increased by mean 0.15 mm and 1.86%,the degree of aggregation decreased by mean 1.32%,and the erosion resistance weakened,which consequently led to aggregate stability decreased.In addition,soil free,amorphous,and crystalline iron oxide as well as soil organic matter and clay contents are all important factors affecting the stability of water-stable aggregates,and their changes in their contents were consistent with those in the stability of water-stable aggregates.The results of this study suggest that long-term planting fruit trees can exacerbate the damaging effects of SFT on aggregate stability and further soil erosion increases and nutrient losses in an orchard,which hider sustainable use of soil and the productivity orchards. 展开更多
关键词 water-stable aggregates orchard age apple-pear orchard soil seasonal freezing and thawing soil degradation high cold region
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Variability of Tropical Cyclone in High Frequent Occurrence Regions over the Western North Pacific 被引量:1
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作者 YANG Yuxing HUANG Fei WANG Faming 《Journal of Ocean University of China》 SCIE CAS 2014年第3期347-355,共9页
In this study, three high frequent occurrence regions of tropical cyclones(TCs), i.e., the northern South China Sea(the region S), the south Philippine Sea(the region P) and the region east of Taiwan Island(the region... In this study, three high frequent occurrence regions of tropical cyclones(TCs), i.e., the northern South China Sea(the region S), the south Philippine Sea(the region P) and the region east of Taiwan Island(the region E), are defined with frequency of TC's occurrence at each grid for a 45-year period(1965–2009), where the frequency of occurrence(FO) of TCs is triple the mean value of the whole western North Pacific. Over the region S, there are decreasing trends in the FO of TCs, the number of TCs' tracks going though this region and the number of TCs' genesis in this region. Over the region P, the FO and tracks demonstrate decadal variation with periods of 10–12 year, while over the region E, a significant 4–5 years' oscillation appears in both FO and tracks. It is demonstrated that the differences of TCs' variation in these three different regions are mainly caused by the variation of the Western Pacific Subtropical High(WPSH) at different time scales. The westward shift of WPSH is responsible for the northwesterly anomaly over the region S which inhibits westward TC movement into the region S. On the decadal timescale, the WPSH stretches northwestward because of the anomalous anticyclone over the northwestern part of the region P, and steers more TCs reaching the region P in the greater FO years of the region P. The retreating of the WPSH on the interannual time scale is the main reason for the FO's oscillation over the region E. 展开更多
关键词 high frequent occurrence regions frequency of tropical cyclone's occurrence western Pacific subtropical high
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Structural analysis and design of frost resistance function for subgrade of high-speed railway ballasted track in cold regions 被引量:1
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作者 Qiang Luo WenQiang Lv +1 位作者 QingZhi Ye RuiGuo Zhang 《Research in Cold and Arid Regions》 CSCD 2015年第5期594-604,共11页
According to the technical characteristics of short fixed wheelbase of a high-speed carriage, a subgrade-track integrated space mechanical response analysis model is proposed for trains under the action ofbiaxial load... According to the technical characteristics of short fixed wheelbase of a high-speed carriage, a subgrade-track integrated space mechanical response analysis model is proposed for trains under the action ofbiaxial load after the comparison of the stress distribution characteristics of the ballast track subgrade bed structures for high-speed railway under the action of uniaxial load and biaxial load. The loading threshold value (high-cycle long-term dynamic strength) under the circum- stance where the cumulative deformation of subgrade structure gradually develops and finally reaches the convergent state, and its relationship with the foundation coefficient K30 were deduced, based on the characteristics of cumulative defor- mation evolution obtained from the unit structure filling model test under the action of cyclic loading. In view of structure stability and frost resistance requirements of the railway subgrade in cold regions, technical conditions to maintain good service performance of subgrade structure of high-speed railway ballasted track are discussed and analyzed. Study results show that the additive effect manifests itself obviously for railway train bogies under the action of biaxial load than uni- axial load, which has a significant dynamic effect on the subgrade bed bottom and a slight effect on the surface layer. Thus, the adoption of a biaxial load model in the design of a high-speed railway subgrade accurately reflects the vehicle load. Pursuant to the structure design principle, the design method of the subgrade structure of high-speed railway ballasted track is proposed to meet the technical requirements such as structural strength, bearing stiffness and high-cyclic and long-term stability. Technical indicators are obtained for the variation of thickness of the surface layer of reinforced sub- grade bed in the double-layer subgrade mode along with the change of K30 at the subgrade bed bottom. The double-layer structure mode of "closure on the upper layer and drainage on the lower layer" was proposed in order to meet the water- proofing and drainage requirements of the upper layer of the subgrade bed in cold regions. A dense-framework graded gravel filler with weak water permeability at a coefficient of 10 4 cm/s is used on the upper layer and the void-framework graded gravel filler at the water permeability coefficient of 10 2 cm/s is adopted on the lower layer. 展开更多
关键词 high-speed railway in cold regions subgrade structure biaxial load mode structural analysis design of frostresistance function
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Primary Screening for Breast Diseases among 17618 Women in Wufeng Area, a Region with High Incidence of Cervical Cancer in China 被引量:4
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作者 张庆华 刘眈 +23 位作者 黄传英 胡婷 沈健 胡美玲 杨茹 陈枝岚 来主会 刘桂玲 梅业冬 向群英 李雄 黄科程 王少帅 潘秀玉 严玉婷 李夜 陈茜 奚玲 邓东锐 汪辉 王世宣 卢运萍 马丁 李双 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2012年第2期252-256,共5页
In this study, the current status for breast diseases in a region with high-incidence of cervical cancer were epidemiologically investigated. From March to August, 2009, 17618 women, from Wufeng area of Hubei province... In this study, the current status for breast diseases in a region with high-incidence of cervical cancer were epidemiologically investigated. From March to August, 2009, 17618 women, from Wufeng area of Hubei province, China, were recruited to screen breast diseases by using breast infrared diagnostic apparatus. Other diagnostic methods, such as B-mode ultrasound, X-ray mammography, needle biopsy and pathological examination were, if necessary, used to further confirm the diagnosis. The screening showed that 5990 of 17618 cases (34.00%) had breast diseases, 5843 (33.16%) had mammary gland hyperplasia, 48 (0.27%) had breast fibroadenoma, 11 (0.06%) had breast carcinoma, and 88 (0.50%) had other breast diseases. The peak morbidity of breast cancer was found in the women aged 50–60 ages. The morbidity of breast cancer was significantly increased in women elder than or equal to 50 years old (n=8, 0.157%) in comparison with that in the subjects younger than 50 years old (n=3, 0.024%) (u=2.327, P<0.05). It was shown that the occurrence of breast diseases was concentrated in women aged 20–40 years, while the total morbidity reached its peak at the age of 30 years and then decreased sharply after age of 40. Compared with the patients elder than or equal to 40 years old (n=3289, 27.46%), the morbidity rate of breast diseases was significantly increased in women less than 40 years old (2648 cases, 47.18%; P<0.001). However, there was no significant difference in the morbidity of breast diseases between the age group of 20–29 years and that of 30–39 years (P=0.453), and both of them were high. There was no significant association between the morbidity of breast diseases and cervical cancer. Since the morbidity of breast diseases was higher among young women, more attention should be paid to the screening of breast diseases among young women for early diagnosis. 展开更多
关键词 cervical cancer breast diseases SCREENING high-incidence region
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EPIDEMIC STRENGTH OF CARDIA AND DISTANT STOMACH CANCER IN THE HIGH RISK REGION OF ESOPHAGEAL CANCER AND THEIR IMPLICATION TO EDOSCOPIC SCREENING 被引量:11
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作者 张立玮 温登瑰 +10 位作者 李英赛 于卫芳 王顺平 尔立绵 丛庆文 王俊和 李素平 李永伟 马彩芬 单宝恩 王士杰 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2006年第2期111-115,共5页
Objective: To discuss the epidemic strength of cardia and distant stomach cancers in the high risk region of esophageal cancer along the south Taihang mountain such as in Shexian, Linxian, and Cixian Counties, and to... Objective: To discuss the epidemic strength of cardia and distant stomach cancers in the high risk region of esophageal cancer along the south Taihang mountain such as in Shexian, Linxian, and Cixian Counties, and to clarify the tasks for the control of upper gastrointestinal tract cancer as a whole in the region. Methods: Comparisons of incidence and mortality rates of esophageal, cardia and stomach cancers were made between Cixian, Linxian and Shexian Counties with reference to detection rates of cancer in situ and precancerous lesions of the three upper gastrointestinal cancers by endoscopic screening. The screening was performed from 1999 through 2004 in the three adjacent counties including a total of 6233 local residents aged 40 to 69 years old. Results: The incidence rates for cardia cancer for the male and female from 2000 through 2004 were 69.9 and 41.5, and the mortality rates were 54.3 and 33.2 respectively in Shexian County. Esophageal, cardia, and stomach cancers constitute about 70~80 percent of all malignant disease by incidence or mortality rates. Endoscopic survey with iodine staining can effectively detect squamous cell precancerous lesions in the esophagus, but the method is inadequate for the detection of adeno precancerous lesions of the cardia and stomach. Conclusion: The south Taihang mountain region is a high risk area not only for esophagus cancer, but also for cardia and stomach cancers. To control upper gastrointestinal tract cancers as a whole in the region, special attention should be paid to the control of cardia and stomach cancers. Presently, to find effective screening methods for detecting cardia and stomach precancerous lesions is especially important. 展开更多
关键词 high-risk region for esophageal cancer Cardia cancer Stomach cancer Precancerous disease Endoscopic screening
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In situ detection of the electron diffusion region of collisionless magnetic reconnection at the high-latitude magnetopause 被引量:3
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作者 Qiu-Gang Zong Hui Zhang 《Earth and Planetary Physics》 2018年第3期231-237,共7页
Magnetic reconnection is the most fundamental energy-transfer mechanism in the universe that converts magnetic energy into heat and kinetic energy of charged particles.For reconnection to occur,the frozen-in condition... Magnetic reconnection is the most fundamental energy-transfer mechanism in the universe that converts magnetic energy into heat and kinetic energy of charged particles.For reconnection to occur,the frozen-in condition must break down in a localized region,commonly called the ‘diffusion region'.In Earth's magnetosphere,ion diffusion regions have already been observed,while electron diffusion regions have not been detected due to their small scales(of the order of a few km)(Paschmann,2008).In this paper we report,for the first time,in situ observations of an active electron diffusion region by the four Cluster spacecraft at the Earth's highlatitude magnetopause.The electron diffusion region is characterized by nongyrotropic electron distribution,strong field-aligned currents carried by electrons and bi-directional super-Alfvénic electron jets.Also observed were multiple micro-scale flux ropes,with a scale size of about 5 c/ω_(pe)(12 km,with c/ωpe the electron inertial length),that are crucial for electron acceleration in the guide-field reconnection process(Drake et al.,2006 a).The data demonstrate the existence of the electron diffusion region in collisionless guide-field reconnection at the magnetopause. 展开更多
关键词 ELECTRON diffusion region magnetic RECONNECTION high-LATITUDE MAGNETOPAUSE
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ANALYSIS ON EFFECT OF SOUTH ASIA HIGH ON MID-SUMMER EXTREME DROUGHT AND FLOOD IN SICHUAN-CHONGQING REGION
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作者 陈永仁 李跃清 齐冬梅 《Journal of Tropical Meteorology》 SCIE 2014年第2期163-172,共10页
NCEP/NCAR data are utilized to analyze an extreme flood year(1998) and an extreme dry year(2006) in the Sichuan-Chongqing region(SCR) and the results are as follows. The positive divergence of South Asia High(SAH) is ... NCEP/NCAR data are utilized to analyze an extreme flood year(1998) and an extreme dry year(2006) in the Sichuan-Chongqing region(SCR) and the results are as follows. The positive divergence of South Asia High(SAH) is stronger in the flood year; the position of the ridge line of SAH is southward compared with the annual average; Western Pacific Subtropical High(WPSH) extends westward and its ridge line is southward. In the drought year, the positive divergence of SAH is weaker, its ridge line is northward, and the position of WPSH is also northward. As shown in the dynamics, in drought(flood) years, negative(positive) vorticity advection in the upper atmosphere can cause the atmosphere to ascend(descend), and anomalous circulation of SAH displays divergence(convergence), and anomalous circulation of the lower atmosphere shows convergence(divergence). Thermal structure of the atmosphere shows that there is warm(cold) temperature advection in the lower atmosphere, and the vertical distribution of diabetic heating causes SAH's local circulation to display convergence(divergence) and affects vertical motion of the lower atmosphere circulation eventually. To some extent, the two extreme years in the SCR is closely related to the vertical motion of atmosphere circulation and the variation of such vertical motion is caused by differences of interactions between SAH and lower atmosphere circulations. 展开更多
关键词 Sichuan-Chongqing region South Asia high(SAH) characteristics of drought and flood anomalous circulation
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Fine upper crustal structure of Jiashi strong earthquake swarm region in Xinjiang in-ferred from high resolution seismic refraction profile data
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作者 徐朝繁 张先康 +3 位作者 段永红 杨卓欣 鄷少英 胡修奇 《Acta Seismologica Sinica(English Edition)》 EI CSCD 2006年第1期62-71,共10页
The data obtained from a high resolution seismic refraction profile, which was carded out in Jiashi, Xinjiang, strong earthquake swarm area, were processed with both finite difference inversion and Hagedoorn refractor... The data obtained from a high resolution seismic refraction profile, which was carded out in Jiashi, Xinjiang, strong earthquake swarm area, were processed with both finite difference inversion and Hagedoorn refractor wavefront imaging technique and the fine upper crustal structure was determined. The results show that the upper crustal structure is relatively well-distributed in laterally and obviously by layers vertically.From surface to 11.0 km depth, there are about four layers. The P wave velocity of top two layers range from 1.65 to 4.5 km/s and their bottom boundaries, the buried depths of which are 0.4, 2.96-3.0 km respectively, are almost horizontal; The third layer is comparatively complicated and its P wave velocity presents inhomogeneous in both laterally and vertically. The bottom boundary of third layer is crystalline basement and shows a little uplift, which seemly suggest that the upper crust had been resisted while the hard Tarim block inserting into Tianshan Mountain; The forth layer is relatively even and its P wave velocity is about 6.3 km/s. There are a lateral velocity variation at the depth of about 4.0 km, and suggest that it has something to do with the hidden Meigaiti fault and Meigaiti-Xiasuhong fault but there are no the structure features about these faults stretching to the surface and passing through the crystalline basement. The seismogenic tectonic of Jiashi strong earthquake swarm at least lies in middle or lower crust beneath 11.0 km depth. 展开更多
关键词 Jiashi strong earthquake swarm region high resolution refraction finite different inversion Hagedoorn principle refractor wavefront imaging
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Computer Simulation of Plastic Deformation in GrainBoundary Region under High Rate Loading
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作者 K.P.Zolnikov S.G.Psakhie S-I.Negrskul and S. Yu.Korostelev (Institute of Strength Physics and Materials Science, Russian Academy of Sicences, Siberian Branch,Akademicheskii pr.2/1, 634048 Tomsk, Russia)(To whom correspondence should be addressed) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1996年第3期235-237,共3页
The computer simulation of Al three-dimensional crystallite containing grain boundary of special type was carried out and its behaviour under high rate loading was investigated. The molecular dynamics method was used ... The computer simulation of Al three-dimensional crystallite containing grain boundary of special type was carried out and its behaviour under high rate loading was investigated. The molecular dynamics method was used and interaction betwen atoms was described based on pseudopotential method. Vortical character of the atom movements in the grain boundary region is realized under shear loading in certain directions. Back and forth movements of atoms in the direction which is perpendicular to the shear also arise. Amplitude of such movements is approximately equal to an interplanar distance in this direction. 展开更多
关键词 SIMULATION Computer Simulation of Plastic Deformation in GrainBoundary region under high Rate Loading
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Address by the UN High Commissioner for Human Rights Ms. Louise Arbour at the Opening Ceremony of the 13th Annual Workshop of the Framework on Regional Cooperation for the Promotion and Protection of Human Rights in the Asia-Pacific Region 被引量:1
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作者 Louise Arbour 《The Journal of Human Rights》 2005年第6期4-6,共3页
关键词 Louise Arbour at the Opening Ceremony of the 13th Annual Workshop of the Framework on regional Cooperation for the Promotion and Protection of Human Rights in the Asia-Pacific region Address by the UN high Commissioner for Human Rights Ms Asia UN
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Treatable focal region modulated by double excitation signal superimposition to realize platform temperature distribution during transcranial brain tumor therapy with high-intensity focused ultrasound 被引量:2
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作者 Shi-Hui Chang Rui Cao +4 位作者 Ya-Bin Zhang Pei-Guo Wang Shi-Jing Wu Yu-Han Qian Xi-Qi Jian 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第7期585-594,共10页
Recently, the phase compensation technique has allowed the ultrasound to propagate through the skull and focus into the brain. However, the temperature evolution during treatment is hard to control to achieve effectiv... Recently, the phase compensation technique has allowed the ultrasound to propagate through the skull and focus into the brain. However, the temperature evolution during treatment is hard to control to achieve effective treatment and avoid over-high temperature. Proposed in this paper is a method to modulate the temperature distribution in the focal region. It superimposes two signals which focus on two preset different targets with a certain distance. Then the temperature distribution is modulated by changing triggering time delay and amplitudes of the two signals. The simulation model is established based on an 82-element transducer and computed tomography (CT) data of a volunteer's head. A finite- difference time-domain (FDTD) method is used to calculate the temperature distributions. The results show that when the distances between the two targets respectively are 7.5-12.5 mm on the acoustic axis and 2.0-3.0 mm in the direction perpendicular to the acoustic axis, a focal region with a uniform temperature distribution (64-65 ℃) can be created. Moreover, the volume of the focal region formed by one irradiation can be adjusted (26.8-266.7 mm3) along with the uniform temperature distribution. This method may ensure the safety and efficacy of HIFU brain tumor therapy. 展开更多
关键词 high-intensity focused ultrasound (HIFU) transcranial therapy double excitation signal superim- position temperature modulation of focal region
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The first discovery of the high prevalence of HTLV infection among blood donors from one village in the southeast coastal region of Fujian Province and its molecuar epidemiological analysis
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《中国输血杂志》 CAS CSCD 2001年第S1期330-,共1页
关键词 HTLV The first discovery of the high prevalence of HTLV infection among blood donors from one village in the southeast coastal region of Fujian Province and its molecuar epidemiological analysis high
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The influence of the different elements of an organic molecule structure on the main kinetic parameters of its unimolecular reaction in the high-pressure region
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作者 David Krinkin 《Natural Science》 2011年第8期661-682,共22页
The most general dynamic tendencies of the energy redistribution in the high-pressure region are considered. Their influence on the possible deviations from the kinetic conceptions, which is now generally accepted, is... The most general dynamic tendencies of the energy redistribution in the high-pressure region are considered. Their influence on the possible deviations from the kinetic conceptions, which is now generally accepted, is examined. In this way, the structural elements of an organic molecule that promote internal energy mobilization in the high-pressure region and, conversely, hamper it, are defined. The first of these elements reduces both the Arrhenius parameters of the unimolecular reactions while the second leads to the opposite results. Some well-known exceptions to existing kinetic theories, which find an explanation in the framework of these proposed concepts, is considered. The proposed concept is very general as distinct from the existing dynamic studies, which investigate more particular details of the separate bond behaviors. The proposed general concept can broaden the study of chemical kinetics. 展开更多
关键词 ARRHENIUS Parameters A-FACTOR high-Pressure region
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New SOI power device with multi-region high-concentration fixed interface charge and the model of breakdown voltage
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作者 李琦 李海鸥 +2 位作者 唐宁 翟江辉 宋树祥 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第3期308-312,共5页
A new SOI power device with multi-region high-concentration fixed charge(MHFC) is reported. The MHFC is formed through implanting Cs or I ion into the buried oxide layer(BOX), by which the high-concentration dynam... A new SOI power device with multi-region high-concentration fixed charge(MHFC) is reported. The MHFC is formed through implanting Cs or I ion into the buried oxide layer(BOX), by which the high-concentration dynamic electrons and holes are induced at the top and bottom interfaces of BOX. The inversion holes can enhance the vertical electric field and raise the breakdown voltage since the drain bias is mainly generated from the BOX. A model of breakdown voltage is developed, from which the optimal spacing has also been obtained. The numerical results indicate that the breakdown voltage of device proposed is increased by 287% in comparison to that of conventional LDMOS. 展开更多
关键词 multi-region high-concentration fixed interface charge model of breakdown voltage
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High-Accuracy Confidence Regions for Distribution Parameters
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作者 Jan Vrbik 《Applied Mathematics》 2022年第6期488-501,共14页
With the help of today’s computers, it is always relatively easy to find maximum-likelihood estimators of one or more parameters of any specific statistical distribution, and use these to construct the corresponding ... With the help of today’s computers, it is always relatively easy to find maximum-likelihood estimators of one or more parameters of any specific statistical distribution, and use these to construct the corresponding approximate confidence interval/region, facilitated by the well-known asymptotic properties of the likelihood function. The purpose of this article is to make this approximation substantially more accurate by extending the Taylor expansion of the corresponding probability density function to include quadratic and cubic terms in several centralized sample means, and thus finding the corresponding -proportional correction to the original algorithm. We then demonstrate the new procedure’s usage, both for constructing confidence regions and for testing hypotheses, emphasizing that incorporating this correction carries minimal computational and programming cost. In our final chapter, we present two examples to indicate how significantly the new approximation improves the procedure’s accuracy. 展开更多
关键词 high-Accuracy Confidence regions Distribution Parameters
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高海拔严寒地区隧道冻害研究现状及展望 被引量:1
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作者 乔雄 杨小龙 冯勇 《隧道建设(中英文)》 CSCD 北大核心 2024年第2期233-256,I0033-I0056,共48页
针对高海拔严寒地区隧道冻害问题,结合隧道冻害的相关研究,从冻害类型及原因分析、冻害机制、温度场、处置措施等4个方面的现状进行阐述和分析,对当前研究存在的不足和未来的发展方向进行探讨。主要成果为:1)通过对高海拔严寒地区隧道... 针对高海拔严寒地区隧道冻害问题,结合隧道冻害的相关研究,从冻害类型及原因分析、冻害机制、温度场、处置措施等4个方面的现状进行阐述和分析,对当前研究存在的不足和未来的发展方向进行探讨。主要成果为:1)通过对高海拔严寒地区隧道工程实例进行分析,总结4种冻害类型及4种冻害原因;2)基于含水风化层冻胀理论、整体性围岩冻胀理论、衬砌背后积水冻胀理论、裂隙水冻胀理论等4种冻胀理论,建立多年冻土区以整体性围岩冻胀理论为主、季冻区以裂隙水冻胀理论为主的多理论联合分析的方法;3)温度场研究方法分为现场监测、理论解析、模型试验、数值模拟等4种,其中现场监测是对洞内外温度进行监测,而理论分析、模型试验、数值模拟则是对监测结果进行验证分析;4)冻害处置措施有防排水措施、保温防寒措施、抗冻措施等3种,防冻的关键是将三者相结合进行综合治理;5)指出冻害机制适用性、温度场研究方法现状、处置措施适用性等方面的不足,未来应在高海拔严寒地区建立多种冻胀理论、多种研究方法综合应用的研究体系,并在隧道防排水、保温防寒、抗冻等方面给出处置措施。 展开更多
关键词 隧道工程 高海拔严寒地区 冻害机制 温度场 处置措施
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新质生产力发展水平、区域差异与提升路径 被引量:95
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作者 卢江 郭子昂 王煜萍 《重庆大学学报(社会科学版)》 CSSCI 北大核心 2024年第3期1-17,共17页
2023年9月,习近平总书记在黑龙江省考察调研期间强调了“新质生产力”这一重要概念,新质生产力是创新起主导作用,摆脱传统经济增长方式、生产力发展路径,具有高科技、高效能、高质量特征,符合新发展理念的先进生产力质态。新质生产力的... 2023年9月,习近平总书记在黑龙江省考察调研期间强调了“新质生产力”这一重要概念,新质生产力是创新起主导作用,摆脱传统经济增长方式、生产力发展路径,具有高科技、高效能、高质量特征,符合新发展理念的先进生产力质态。新质生产力的提出具有全新的理论内涵和丰富的现实价值,结合习近平总书记的相关重要论述和当前中国经济发展事实,文章认为新质生产力是一个至少涵盖科技、绿色和数字三大方面的集成体,并基于科技生产力、绿色生产力和数字生产力3个一级指标构建了新质生产力的综合评价体系。文章采用改进的熵权-TOPSIS方法测度了2012—2021年我国30个省级区域的新质生产力水平,测度结果表明,我国新质生产力水平由2012年的0.302 6上升到2021年的0.874 7,年均增速为21%,对应的,科技生产力、绿色生产力和数字生产力的水平也稳步上升。研究发现,针对不同区域,东部地区新质生产力水平不仅增速最快,总量也高于中西部地区,中部地区新质生产力水平高于西部地区,但增速低于西部地区;针对具体省份,新质生产力形成了广东省和江苏省“双雁领航”断层式发展格局,不同省份之间的差距极大,反映了中国新质生产力水平的区域异质性。进一步研究,Kernel密度估计和Markov链分析结果表明,一方面我国省际新质生产力水平的差距有逐渐拉大趋势,但这一趋势主要存在于个别新质生产力发达和落后的省份之间,大部分中间省份差异不明显,且新质生产力发展存在俱乐部趋同现象,新质生产力发达省份之间的趋同现象更为明显;另一方面,新质生产力发展具有明显的空间外溢效应,在与邻近省份的新质生产力水平存在差异的情况下,本省的新质生产力将会受到邻近省份的影响。新质生产力水平的基尼系数计算及其分解结果表明,区域间差异是全国新质生产力发展不平衡的主要原因,也就是说当下导致新质生产力水平差异的主要原因是地区间的发展不平衡。针对上述问题,提升新质生产力的发展路径应该着重从统筹区域联动合作促进平衡发展,加大对新质生产力发展的引导力度,在新质生产力构成的三大指标上进行新部署等方面展开。 展开更多
关键词 新质生产力 综合评价 区域差异 高质量发展 中国式现代化
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