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Clinical characteristics and clinicopathological correlations of bilateral breast cancer in China:A multicenter study from Chinese Society of Breast Surgery(CSBrS-006) 被引量:4
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作者 Xuelu Li Yitong Wang +5 位作者 Bo Pan Man Li Jiyue Gao Yi Zhao Zuowei Zhao Chinese Society of Breast Surgery 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2021年第1期27-32,共6页
Objective:To investigate the clinical characteristics and clinicopathological correlations of bilateral breast cancer(BBC)in China.Methods:Data of 440 patients diagnosed with BBC in 2018 were collected from 33 centers... Objective:To investigate the clinical characteristics and clinicopathological correlations of bilateral breast cancer(BBC)in China.Methods:Data of 440 patients diagnosed with BBC in 2018 were collected from 33 centers of the Chinese Society of Breast Surgery.Demographic characteristics,bilateral tumor characteristics,and comprehensive treatment data were obtained.Correlations between the clinicopathological characteristics of bilateral tumors were analyzed.Results:The proportion of BBC was 0.22%-3.08%.A total of 33(7.5%)patients had a family history of malignant tumors,304(69.1%)patients had synchronous BBC.Only 1(0.2%)patient was male.More than half of all patients received concurrent or asynchronous endocrine/chemotherapy,32.5%of all human epidermal growth factor receptor 2(HER2)-positive patients received HER2-targeted therapy,and approximately 21.6%of all patients received radiotherapy.The most common pathological cancer type was invasive ductal cancer(>60%).Approximately 70%of all patients had bilateral hormone receptor(HR)-positive tumors and presented with a single breast mass.Significant correlations were found with pathological type,histological grade,locations of tumor,molecular subtype,Ki-67 index,tumor site and size of bilateral tumors.Results of the subgroup analysis showed more clinicopathological characteristics when synchronous BBC was compared with metachronous BBC.Conclusions:In China,the clinicopathological characteristics of bilateral tumors showed significant correlations,and more significant clinicopathological correlations were observed when synchronous BBC was compared with metachronous BBC. 展开更多
关键词 Adjuvant therapy bilateral breast cancer clinicopathological correlation demographic characteristics
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Research on Correlation between TCM Syndrome Distribution Characteristics and Prognosis of Hypertensive Intracerebral Hemorrhage Operation 被引量:2
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作者 Gang Yang Jianju Feng +6 位作者 Shaojun Yang Junjie Lv Donghai Yuan Chenbing Wang Feng Ding Chao Gu Gaofeng Shao 《Journal of Biosciences and Medicines》 2021年第4期138-144,共7页
<strong>Objective: </strong>This study is to analyze correlation between traditional Chinese medicine (TCM) syndrome distribution characteristics and prognosis of hypertensive intracerebral hemorrhage (HIC... <strong>Objective: </strong>This study is to analyze correlation between traditional Chinese medicine (TCM) syndrome distribution characteristics and prognosis of hypertensive intracerebral hemorrhage (HICH) operation. <strong>Methods: </strong>In this study, a total of 150 patients who had received HICH operation from April, 2017 to December, 2020 in our hospital and conformed to inclusion standards were selected. According to classification of TCM syndromes, amount of bleeding of patients was recorded through multiple radiological technologies, baseline information was collected, and prognosis was investigated. The final event was long-term follow-up visit of all-cause mortalities. Moreover, correlation between prognosis and TCM syndromes was analyzed. <strong>Results:</strong> It found through investigations that there are no statistically significant differences in composition ratio of TCM syndromes among patients with different genders and different age ranges (P > 0.05). Among so many TCM syndromes, bleeding amount of patients with declining vitality and distraction is the highest, while bleeding amount of patients with stirring wind due to yin deficiency is the lowest. With respect NIHSS scores, the patients with declining vitality and distraction show the highest NIHSS scores at admission and 10 d of the course of the disease, followed by patients with upward disturbance of wind-fire. There are statistically significant differences among these two groups (P < 0.05). In this study, follow-up visits are performed to all 150 patients and the average follow-up visit time ranges within 2 - 15 months. A total of 13 deaths are reported. Number of all-cause deaths has statistically significant differences among different syndromes (P < 0.05). <strong>Conclusions:</strong> Evolutionary characteristics of TCM syndromes of HICH are manifested by development from evidence-based symptoms to deficiency syndromes. Different syndromes are correlated with prognosis of patients. On the one hand, this can be used as an objective index for TCM syndrome classification. On the other hand, this is conducive to judge prognosis recovery of patients and to apply the corresponding symptomatic treatment. 展开更多
关键词 HICH TCM Syndromes Distribution characteristics PROGNOSIS correlation
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Study on soil water characteristics of tobacco fields based on canonical correlation analysis 被引量:1
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作者 Xiao-hou SHAO Yu WANG +3 位作者 Li-dong BI You-bo YUAN Xian-kun SU Jian-guo MO 《Water Science and Engineering》 EI CAS 2009年第2期79-86,共8页
In order to identify the principal factors influencing soil water characteristics (SWC) and evaluate SWC effectively, the multivariate-statistical canonical correlation analysis (CCA) method was used to study and ... In order to identify the principal factors influencing soil water characteristics (SWC) and evaluate SWC effectively, the multivariate-statistical canonical correlation analysis (CCA) method was used to study and analyze the correlation between SWC and soil physical and chemical properties. Twenty-two soil samples were taken from 11 main tobacco-growing areas in Guizhou Province in China and the soil water characteristic curves (SWCC) and basic physical and chemical properties of the soil samples were determined. The results show that: (1) The soil bulk density, soil total porosity and soil capillary porosity have significant effects on SWC of tobacco fiels. Bulk density and total porosity are positively correlated with soil water retention characteristics (SWRC), and soil capillary porosity is positively correlated with soil water supply characteristics (SWSC). (2) Soil samples from different soil layers at the same soil sampling point show similarity or consistency in SWC. Inadequate soil water supply capability and imbalance between SWRC and SWSC are problems of tobacco soil. (3) The SWC of loamy clay are generally superior to those of silty clay loam. 展开更多
关键词 canonical correlation analysis tobacco soils soil water characteristics soil texture
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Clinical Characteristics of 5 Chinese LQTS Families and Phenotype-genotype Correlation
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作者 廉姜芳 崔长琮 +2 位作者 薛小临 黄辰 崔翰斌 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2004年第3期208-211,共4页
Summary: In order to assess the clinical manifestations and electrocardiogram (ECG) characteristics of Chinese long QT syndrome (LQTS) patients and describe the phenotype-genotype correlation, the subjects from 5 cong... Summary: In order to assess the clinical manifestations and electrocardiogram (ECG) characteristics of Chinese long QT syndrome (LQTS) patients and describe the phenotype-genotype correlation, the subjects from 5 congenital LQTS families underwent clinical detailed examination including resting body surface ECG. QT interval and transmural dispersion of repolarization (TDR) were manually measured. Five families were genotyped by linkage analysis (polymerase chain reacting-short tandem repeat, PCR-STR). The phenotype-genotype correlation was analyzed. Four families were LQT2, 1 family was LQT3. Twenty-eight gene carriers were (14 males and 14 females) identified from 5 families. The mean QTc and TDRc were 0.56±0.04 s (range 0.42 to 0.63) and 0.16±0.04 s (range 0.09 to 0.24) respectively. 35.7 % (10/28) had normal to borderline QTc (≤ 0.460 s). There was significant difference in QTc and TDRc between the patients with symptomatic LQTS and those with asymptomatic LQTS, and there was significant difference in TDRc between the asymptomatic patients and normal people also. A history of cardiac events was present in 50 % (14/28), including 9 with syncope, 2 with sudden death (SD) and occurred in the absence of β-blocker. Three SDs occurred prior to the diagnosis of LQTS and had no ECG record. Two out of 5 SDs (40 %) occurred as the first symptom. Typical LQT2 T wave pattern were found in 40 % (6/15) of all affected members. The appearing-normal T wave was found in one LQT3 family. Low penetrance of QTc and symptoms resulted in diagnostic challenge. ECG patterns and repolarization parameters may be used to predict the genotype in most families. Genetic test is very important for identification of gene carriers. 展开更多
关键词 long QT syndrome clinical characteristics phenotype-genotype correlation
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Correlation Analysis of Quantitative Microscopic Characteristics and Polysaccharide Content of Dendrobium officinale from Guangxi
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作者 Liuyuan FAN Hua ZHU +2 位作者 Jianbei TENG Zhonghua DAI Piaoling HUANG 《Medicinal Plant》 CAS 2022年第4期1-7,11,共8页
[Objectives]The paper was to investigate the correlation between the microscopic characteristic constants and the index component polysaccharide content of Dendrobium officinale from Guangxi.[Methods]The paraffin sect... [Objectives]The paper was to investigate the correlation between the microscopic characteristic constants and the index component polysaccharide content of Dendrobium officinale from Guangxi.[Methods]The paraffin sections of D.officinale were made,and the microscopic characteristic constants of D.officinale stem,including cross section area,vascular bundle area and phloem area,were determined by NIS-Elements D microscopic image processing software.The contents of polysaccharides in D.officinale were determined by UV-Vis spectrophotometry,and the quantitative values of microscopic characteristics of D.officinale with different growth years were analyzed by SPSS 23.0(IBM SPSS Statistics 23.0)data statistical software.The correlation between quantitative microscopic characteristics of D.officinale and its polysaccharide content was analyzed.[Results]According to the correlation between the index component of D.officinale and its quantitative microscopic characteristics,the measurement indexes,the percentage of vascular bundle in the cross section area and the percentage of hard structure in the cross section area,were strongly negatively correlated with polysaccharide content.[Conclusions]The microscopic characteristic constant values of vascular bundles of D.officinale can be used as a method to verify polysaccharide content. 展开更多
关键词 Dendrobium officinale Microscopic characteristics POLYSACCHARIDES correlation analysis
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Correlations among Important Fruit Quality and Plant Characteristics of Some Fig Genotypes
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作者 A. Aytekin Polat Oguzhan Caliskan 《Journal of Life Sciences》 2017年第3期141-144,共4页
Experiments were carried to determine correlations of important fruit and plant characteristics using 30 fig genotypes. The correlation coefficients between these traits were calculated using SAS program. Fruit weight... Experiments were carried to determine correlations of important fruit and plant characteristics using 30 fig genotypes. The correlation coefficients between these traits were calculated using SAS program. Fruit weight, fruit diameter, fruit length, neck length, ostiolium width, abscission of the stalk from the twig, ease of peeling, fruit skin cracks, thickness of the fruit skin, texture of skin, fruit ribs, fruit internal cavity, TSS (total soluble solids), pH, acidity, TSS/acidity, trunk diameter, shoot length, yield per tree were traits examined in the study. According to five-year data, fruit weight was found to have positive correlation by fruit diameter (r = 0.92; P 〈 0.01), fruit length (r = 0.81; P 〈 0.01), neck length (r = 0.35; P 〈 0.01), ostiolium width (r = 0.23; P 〈 0.01), trunk diameter (r = 0.26; P 〈 0.01), fruit skin cracks (r = 0.26; P 〈 0.01) and negative correlation by TSS (r = -0.26; P 〈 0.01) and fruit ribs (r = -0.21; P 〈 0.01). Relations between some traits such as ostiolium width, abscission of the stalk from the twig, ease of peeling, fruit skin cracks, texture of skin and fruit ribs are deviated based on the years. Some relationships between fig fruit characteristics exist, which may help researchers to solve some problems such as ostiolium width and fruit skin cracking. These studies may contribute to producing fruit with a good quality and help to evaluate new cultivars. 展开更多
关键词 Fig genotype fruit quality plant characteristic correlation.
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Suppression of Pulse Interference in Partial Discharge Measurement Based on Phase Correlation and Waveform Characteristics
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作者 Shengyou Gao Qi Wang Junfeng Gui Yunfeng Xia Jianhua Lin Jianhua Huang Xiyang Chen 《Journal of Energy and Power Engineering》 2015年第3期289-295,共7页
Partial discharge measurement is one of the most effective methods to find insulation defects and early failure of high voltage power equipments. The accuracy is significantly reduced by the interference in the partia... Partial discharge measurement is one of the most effective methods to find insulation defects and early failure of high voltage power equipments. The accuracy is significantly reduced by the interference in the partial discharge on-site detection or on-line monitoring, especially by the pulse interference. This paper studies the phase correlation of some types of typical partial discharge pulses and their characteristics in time domain and frequency domain. By collecting enough partial discharge pulse data, the correlation coefficient can be calculated based on both phase correlation and waveform similarity. The type of pulse will be determined by the scope of the calculated correlation coefficient. The pulses with very strong correlation will be identified as periodic pulse interference. The pulses with very weak correlation will be identified as random pulse interference. Only the pulses whose correlation coefficients fall into a specific range will be identified as partial discharge signals. In laboratory, simulated pulse interference is injected into measurement circuit, and typical partial discharge pulses are sampled by a high-speed acquisition system. The pulse interference can be effectively separated from partial discharge signals by correlation coefficient. 展开更多
关键词 correlation coefficient partial discharge phase correlation pulse interference waveform characteristic.
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Expression of DLK1 protein and its correlation with renal cell carcinoma pathological characteristics
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作者 邹霜梅 《外科研究与新技术》 2011年第4期235-235,共1页
Objective To identify the expression of DLK1 protein in different types of renal cell carcinomas and its correlations with pathological characteristics and metastasis. Methods Immunohistochemistry analysis was perform... Objective To identify the expression of DLK1 protein in different types of renal cell carcinomas and its correlations with pathological characteristics and metastasis. Methods Immunohistochemistry analysis was performed to evaluate the expression of DLK1 protein in 展开更多
关键词 DLK CELL Expression of DLK1 protein and its correlation with renal cell carcinoma pathological characteristics
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Dynamic characteristics of the planetary gear train excited by time-varying meshing stiffness in the wind turbine 被引量:3
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作者 Rui-ming Wang Zhi-ying Gao +2 位作者 Wen-rui Wang Yang Xue De-yi Fu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2018年第9期1104-1112,共9页
Wind power has attracted increasing attention as a renewable and clean energy. Gear fault frequently occurs under extreme environment and complex loads. The time-varying meshing stiffness is one of the main excitation... Wind power has attracted increasing attention as a renewable and clean energy. Gear fault frequently occurs under extreme environment and complex loads. The time-varying meshing stiffness is one of the main excitations. This study proposes a 5 degree-of-freedom torsional vibration model for the planetary gear system. The influence of some parameters(e.g., contact ratio and phase difference) is discussed under different conditions of a single teeth pair and double pairs of teeth. The impact load caused by the teeth face fault, ramped load induced by the complex wind conditions, and the harmonic excitation are investigated. The analysis of the time-varying meshing stiffness and the dynamic meshing force shows that the dynamic design under different loads can be made to avoid resonance, can provide the basis for the gear fault location of a wind turbine, and distinguish the fault characteristics from the vibration signals. 展开更多
关键词 wind TURBINE PLANETARY GEAR time-varying MESHING stiffness dynamic characteristics
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Efficient computation for dynamic responses of systems with time-varying characteristics 被引量:2
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作者 Liang Ma Yudong Chen Suhuan Chen Guangwei Meng Department of Mechanics, Nanling Campus,Jilin University, 130025 Changchun, China 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2009年第5期699-705,共7页
Based on Neumman series and epsilon-algorithm, an efficient computation for dynamic responses of systems with arbitrary time-varying characteristics is investigated. Avoiding the calculation for the inverses of the eq... Based on Neumman series and epsilon-algorithm, an efficient computation for dynamic responses of systems with arbitrary time-varying characteristics is investigated. Avoiding the calculation for the inverses of the equivalent stiffness matrices in each time step, the computation effort of the proposed method is reduced compared with the full analysis of Newmark method. The validity and applications of the proposed method are illustrated by a 4-DOF spring-mass system with periodical time-varying stiffness properties and a truss structure with arbitrary time-varying lumped mass. It shows that good approximate results can be obtained by the proposed method compared with the responses obtained by the full analysis of Newmark method. 展开更多
关键词 Dynamic responses Efficient computation Epsilon-algorithm time-varying characteristics
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Spatial Characteristics and Change for Tree Species (Genera) Along Northeast China Transect (NECT) 被引量:4
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作者 陈雄文 张新时 +1 位作者 周广胜 陈锦正 《Acta Botanica Sinica》 CSCD 2000年第10期1075-1081,共7页
The 16 tree species on Northeast China Transect (NECT) were analyzed from the change of geographical distribution, frequency and dominance pattern and the spatial correlation at landscape scale in 1986 and 1994. Pin... The 16 tree species on Northeast China Transect (NECT) were analyzed from the change of geographical distribution, frequency and dominance pattern and the spatial correlation at landscape scale in 1986 and 1994. Pinus koraiensis Sieb. et Zucc. and Fraxinus rhynchophylla Hemsl. had spread rapidly towards west and east, respectively. The frontier form of species had close relation with its movement. The patch size of Pinus koraiensis , Populus davidiana Dode., Phellodendron amurense Rupr., Juglans mandshurica Maxim., Fraxinus mandshurica Rupr., Betula dahurica Pall., Picea koraiensis Nakai, Abies nephrolepis Maxim. and Larix olgeusis var. koreana Nakai decreased, however, Quercus mongolica Fisch., Betula costata Trautv., Acer mono Maxim., Tilia spp., Ulmus spp., Betula platyphylla Suk. and Fraxinus rhynchophylla increased. The frequency pattern of Populus davidiana , Betula platyphylla , Fraxinus rhynchophylla and Betula dahurica changed significantly. The dominance pattern of Populus davidiana , Tilia spp., Juglans mandshurica , Betula platyphylla , Betula dahurica and Abies nephrolepis changed significantly. The spatial correlation between Quercus mongolica and Betula dahurica , Betula costata and Picea spp., Betula costata and Abies nephrolepis , Picea spp. and Abies nephrolepis declined, however, the spatial correlation between Larix spp. and Betula platyphylla , Acer mono and Ulmus spp. increased. 展开更多
关键词 spatial characteristic tree species(genera) Northeast China Transect PATCH frequency DOMINANCE spatial correlation
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Grey Correlation Analysis of Physiological Traits Related to Drought Tolerance in Pennisetum sp. 被引量:1
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作者 苏德伟 梅兰 +5 位作者 林辉 罗海凌 张丽丽 宋静 刘军 林占熺 《Agricultural Science & Technology》 CAS 2017年第7期1158-1163,共6页
The drought resistance of Pennisetum sp. was analyzed under different drought stress conditions simulated by various concentrations of PEG-6000. Changesofa series of indexes such as chlorophyll content, water content,... The drought resistance of Pennisetum sp. was analyzed under different drought stress conditions simulated by various concentrations of PEG-6000. Changesofa series of indexes such as chlorophyll content, water content, relative electrical conductivity of osmotic solution, MDA content, proline content, soluble polysaccharide content and soluble protein content in the leaves were measured.The correlation of these indexes with the drought resistance of Pennisetum sp. was an- alyzed by the method of grey correlation analysis. The results showed that the chlorophyll, water content, relative electrical conductivity and soluble protein con- tentexhibited obvious negative correlation with the stress concentration, which de- creasedfollowing the increase of PEG-6000 concentration. The soluble polysaccha- ride contentshowed an increasing trend,the MDA content showed a rise at first fol- lowed by a declinetrend, while the prolinecontent was just opposite to MDA. The changes of the 3 indexes showed obvious positive correlation with thestress con- centration. The correlation of these indexes with the drought resistance of Pennise- tum sp. were ranked as follows: leaf water content (0.980 8), chlorophyll content (0.967 9), MDA content (0.876 0), soluble polysaccharide content (0.839 5), soluble protein content(0.827 5), relative electrical conductivity of osmotic solution(0.670 8), and proline content(0.571 3). 展开更多
关键词 Pennisetum sp. Drought tolerance Physiological characteristic Grey correlation analysis
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Genetic study on seed coat characteristics in multiploid watermelon 被引量:1
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作者 陈娟 《Agricultural Science & Technology》 CAS 2007年第2期13-20,共8页
[ Objective] This study is to provide basis for the genetic improvement of triploid watermelon cultivars from seed coat characteristiscs by analyzing its genetic properties. [ Method ] Genetic effects of seed coat cha... [ Objective] This study is to provide basis for the genetic improvement of triploid watermelon cultivars from seed coat characteristiscs by analyzing its genetic properties. [ Method ] Genetic effects of seed coat characteristics and their related characteristics in tdploid watermelon were analyzed by additive dominant genetic model based on 36 F1 hybrids which were crossed by six female parents of four ecotypes and six male parents of same ecotype according to North Carolina II crossing design. [ Result] The seed coat number characteristics was controlled by additive effects, dominant effects and error variance of genetic together. The additive effects of the length and width of abortive seed coat were significant, and the error variance was significant or highly significant. It was observed that there was a significant negative correlation of additive effects between the seed coat number and fringe soluble sugar. Also there was a significant negative correlation of dominant effects between lycopenes, dry matter and the seed coat number. However, there was a highly significant positive correlation in additive effects between the length and width of abortive seed coat. [ Conclusion ] The results provide guidance for genetic breeding of triploid watermelon cultivars. 展开更多
关键词 triploid watermelon seed coat characteristics genetic effect correlation analysis
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Analysis of the Correlation between the Geographical Distribution of Populus euphratica Oliv. and the Climatic Environment
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作者 杨银科 阎正龙 《Agricultural Science & Technology》 CAS 2012年第7期1450-1455,共6页
[Objective] This research was to study the correlation regional climatic characteristics and changing geographic distribution of Populus euphratica Oliv. (Salicaceae), as well as the adaption of Populus euphratica Oli... [Objective] This research was to study the correlation regional climatic characteristics and changing geographic distribution of Populus euphratica Oliv. (Salicaceae), as well as the adaption of Populus euphratica Oliv. to the climatic environment. [Method] The climatic characteristics, water source, groundwater and soil type in the distribution regions of Populus euphratica Oliv. and the effect of long-term human activities were comprehensively analyzed based an overview of Populus euphratica Oliv. and its distribution. [Result] Specific regional climatic characteristics and long term human activities are the principle determinants for the growth of Populus euphratica Oliv. The change of leaf shape is a distinct feature of Populus euphratica Oliv. in adapting to the climatic environment. Populus euphratica Oliv. withstands various environmental stresses by means of in vivo synthesis, transport and conversion of secondary phenolic metabolites. Effective protection and rehabilitation measures, and ecological water transport have obvious effect on the restoration and reconstruction of damaged ecological environment of Populus euphratica oasis. [Conclusion] This study is of great significance for the restoration of ecological environment in the arid inland regions, north-west China. 展开更多
关键词 POPULUS EUPHRATICA Oliv. (Salicaceae) Geographic distribution Climatic and environmental characteristics correlation ANALYSIS
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Geographic variation and genetic performance of Picea koraiensis in growth and wood characteristics 被引量:5
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作者 WANGQiu-yu JIAHong-bai SHANGJie 《Journal of Forestry Research》 SCIE CAS CSCD 2005年第2期93-96,共4页
Eight provenances of 19-year-old Picea koraiensis Nakai from the provenancetrials of Maoershan (45°20′N, 127°30′E), Liang-shui (47°10′N, 128°53′E) and Jiagedaqi(50°24′N, 124°07′E) i... Eight provenances of 19-year-old Picea koraiensis Nakai from the provenancetrials of Maoershan (45°20′N, 127°30′E), Liang-shui (47°10′N, 128°53′E) and Jiagedaqi(50°24′N, 124°07′E) in Northeast China were investigated to analyze the genetic variation ingrowth characteristics (tree height and diameter) and wood characteristics (tracheid length,tracheid diameter, tracheid wall thickness, annual ring width as well as wood density). Greatvariation in height growth and breast height diameter growth was observed among the provenances, andalong with the increase of tree age, these provenances presented different geographic adaptability.The growth characteristics of Picea koraiensis stand at age of 10 in Maoershan and Liangshuiprovenance trials had a positive correlation with longitude, and with increase of tree age to 15 and19, the tree growth of the provenances displayed a significant positive correlation with latitudeas well as altitude. For wood characteristics, great variation was also found among the provenances.There exists a close relation between growth characteristics and wood properties of the provenance.The height and breast height diameter growth of the provenance had a positive correlation withtracheid diameter and annual ring width, and a negative correlation with tracheid wall thickness andwood density. Genetic performance of the provenance in all above characteristics was alsoinvestigated in order to provide more useful information for comprehensive selection of this speciesfor pulpwood and plywood production. 展开更多
关键词 picea koraiensis geographic variation genetic correlation growthcharacteristics wood characteristics
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Chaotic characteristics of electromagnetic emission signals during deformation and fracture of coal 被引量:8
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作者 NIE Bai-sheng HE Xue-qiu +2 位作者 LIU Fang-bin ZHU Cheng-wei WANG Ping 《Mining Science and Technology》 EI CAS 2009年第2期189-193,共5页
Electromagnetic emission(EME) is a kind of physical phenomenon accompanying the process of deformation and fracture of loaded coal and rock and it is of importance in quantitatively analyzing its characteristics.This ... Electromagnetic emission(EME) is a kind of physical phenomenon accompanying the process of deformation and fracture of loaded coal and rock and it is of importance in quantitatively analyzing its characteristics.This will reveal the process of deformation and fracture of coal and predicting dynamic disasters in coal mines.In this study,the G-P(Grassberger and Procaccia) algorithm,calculation steps of the(if only 1 dimension) correlation dimension of time series and the identification standards of chaotic signals are introduced.Furthermore,the correlation dimensions of EME and the acoustic emission(AE) signals of time series during deformation and fracture of coal bodies are calculated and analyzed.The results show that the time series of pulses number of EME and the time series of AE count rate are chaotic and that the saturation embedding dimensions of a K3 coal sample are,respectively,5 and 6.The results can be used to provide basic parameters for predicting of EME and AE time series. 展开更多
关键词 coal and rock electromagnetic emission correlation dimension chaotic characteristics
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Acoustic emission characteristics of rock under impact loading 被引量:8
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作者 刘希灵 李夕兵 +2 位作者 洪亮 尹土兵 饶蒙 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第9期3571-3577,共7页
Acoustic emission tests were performed using a split Hopkinson pressure bar system(SHPB) on 50-mm-diameter bars of granite, limestone, sandstone and skarn. The results show that the amplitude distribution of hits is n... Acoustic emission tests were performed using a split Hopkinson pressure bar system(SHPB) on 50-mm-diameter bars of granite, limestone, sandstone and skarn. The results show that the amplitude distribution of hits is not well centralized around 50 d B, and that some hits with large amplitudes, usually larger than 70 d B, occur in the early stages of each test, which is different from the findings from static and low-loading-rate tests. Furthermore, the dominant frequency range of the recorded acoustic emission waveforms is between 300 k Hz and 500 k Hz, and frequency components higher than 500 k Hz are not significant. The hit with the largest values of amplitude, counts, signal strength, and absolute energy in each test, displays a waveform with similar frequency characteristics and greater correlation with the waveform obtained from the elastic input bar of the split Hopkinson pressure bar system compared with the waveforms of the other hits. This indicates that the hit with the largest values of amplitude, counts, signal strength, and absolute energy is generated by elastic wave propagation instead of fracture within the rock specimen. 展开更多
关键词 ROCK acoustic emission(AE) split Hopkinson pressure bar(SHPB) hit driven features frequency characteristics correlation analysis
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Mechanical properties and damage characteristics of solidified body-coal combination in continuous driving and gangue backfilling 被引量:7
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作者 Yi Tan Hao Cheng +4 位作者 Wenbing Guo Erhu Bai Shaopu Zhang Yu Wang Zihao Li 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第10期1217-1228,共12页
Recovery of the coal buried under buildings,railways and water bodies and the residual coal in irregularly arranged fully mechanized mining faces is a common engineering problem facing underground coal mining.In this ... Recovery of the coal buried under buildings,railways and water bodies and the residual coal in irregularly arranged fully mechanized mining faces is a common engineering problem facing underground coal mining.In this study,a mining technology of continuous driving and gangue backfilling(CDGB)was proposed.The technology,which can not only alleviate ground subsidence and gangue discharge,but also release the above-mentioned coals,contributes to green and efficient sustainable development of mining.The stability of the system of the solidified body-reserved coal pillar combination(S-C combination)is crucial to the CDGB technology.Therefore,it is of great significance to explore the mechanical and damage characteristics of S-C combination in the synergistic bearing process.First,four sets of differentshaped S-C combination specimens were fabricated and a S-C combination bearing structure in CDGB was constructed to explore the differences in mechanical characteristics and damage modes of different-shaped S-C combination specimens during CDGB.Subsequently,their surface strain field evolutions and acoustic emission(AE)response characteristics in the load-bearing process were obtained with the aid of the digital image correlation technique and the AE signal monitoring system.Furthermore,a damage evolution model based on AE parameters and mechanical parameters was established to clarify the damage evolution law.The following results were obtained:(1)The free area of S-C combination can serve as a quantitative index to evaluate the stability of the overburden control system;(2)The concept of critical value k of the free area was first proposed.When the free area exceeds the critical value k(free area ratio greater than 1.13),the deformation resistance and the free area changes becomes negatively correlated;(3)As the free area expands,the failure of the S-C combination specimen evolves from tensile failure to shear failure.The distribution characteristics of the axial strain field also verified such a change in the failure mode;(4)When the free area expands,the peak AE count gradually changes from“double peaks”to“a single peak”.In this process,the expansion of free area shortens the time for accumulating and releasing energy during loading.Micro cracks generated in the specimen change from a phased steep growth to a continuous increase,and the process in which micro cracks develop,converge,intersect and connect to form macro cracks accelerates.The damage evolution law concluded based on AE parameters and mechanical parameters can well characterize the damage evolution process of S-C combination,providing certain reference for the study on the synergistic bearing of S-C combination during CDGB. 展开更多
关键词 Continuous driving and gangue backfilling Solidified body-coal combination Mechanical properties Damage characteristics Digital image correlation technology Acoustic emission
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Bearing characteristics and fatigue damage mechanism of multi-pillar system subjected to different cyclic loads 被引量:5
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作者 ZHOU Zi-long WANG Hai-quan +3 位作者 CAI Xin ZANG Hai-zhi CHEN Lu LIU Fu 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第2期542-553,共12页
Aiming to investigate the fatigue damage mechanism and bearing characteristics of multi-pillar system under cyclic loading,a series of axial cyclic loading tests with different cyclic amplitudes were carried out on tr... Aiming to investigate the fatigue damage mechanism and bearing characteristics of multi-pillar system under cyclic loading,a series of axial cyclic loading tests with different cyclic amplitudes were carried out on triple-pillar marble specimens.The acoustic emission(AE)and digital image correlation(DIC)were jointly applied to monitoring and recording damage evolution and failure behavior of each pillar,which reproduced the cataclysmic instability process of underground pillar groups.Experimental results indicated that the cyclic amplitude exceeding the threshold of damage initiation weakened the resistance to deformation,resulting in obvious release of dissipated energy and the reduction of bearing capacity.Conversely,after low-amplitude cyclic loading,both the pre-peak bearing capacity and the post-peak ductility of the pillar system increased due to the compaction of initial defects,indicating that the peak bearing capacity was closely related to the extent of pre-peak fatigue damage.The axial strain of each pillar was measured by DIC virtual extensometer to present the damage extent during cyclic loading phase.Meanwhile,fracture evolution of typical load drop points was also characterized by transverse strain fields(εxx),and observations showed that the damage extent of key pillar undergoing high-amplitude cyclic loads was more serious and violent,accompanied by the ejection of rock debris and loud noises. 展开更多
关键词 multi-pillar system cyclic loading fatigue damage bearing characteristics acoustic emission(AE) digital image correlation(DIC)
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Distribution Characteristics of Air Anions in Beidaihe in Different Ecological Environments 被引量:2
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作者 Xiakun Zhang Jianxin Cao Shuyu Zhang 《Journal of Geoscience and Environment Protection》 2018年第5期133-150,共18页
Qinhuangdao is a provincial municipality under the jurisdiction of Hebei Province and a coastal city in China. Beidaihe is a district under the jurisdiction of Qinhuangdao and is a famous seaside scenic area. Alliance... Qinhuangdao is a provincial municipality under the jurisdiction of Hebei Province and a coastal city in China. Beidaihe is a district under the jurisdiction of Qinhuangdao and is a famous seaside scenic area. Alliance Peak, located in Beidaihe seashore scenic West. Jinshan mouth is the peak of the Union Peak, located in the easternmost Beidaihe waterfront. In this paper, we use the observed data of air negative ions in the Beidaihe, Qinhuangdao, Jinshanzui and Lianfeng Mountains for seven years to study the distribution characteristics of negative air ions in different ecological environments through meteorological observation. Research shows that the annual mean of air anion concentration fluctuates less. The annual mean is 1730 ind·cm-3, and the difference between the highest and lowest concentrations is 535 ind·cm-3. The average air anion concentration was the highest in August at 7785 ind·cm-3 and the lowest in January at 365 ind·cm-3. Negative air ions have obvious spatial characteristics, and negative ion concentrations of the sea and forest air are significantly high. The average annual mean of the sea is 3902 ind·cm-3, and that of the forest is 5403 ind·cm-3. The concentration of air anion changes daily, and daytime concentration is significantly lower than nighttime concentration. The highest peak appears at night or in the morning, while the lowest value appears between noon and afternoon. Inter-annual features and concentration of negative air ions, as well as annual rain days, total rainfall, thunderstorm days, and average relative humidity, are negatively related to the annual average temperature and sunshine hours. However, in the average concentration of negative air ions, the average correlation test of meteorological elements was insignificant. The air anion concentration is negatively correlated with the PM2.5 concentration of fine particulate matter. The concentrations of nitrogen dioxide, sulfur dioxide, and carbon monoxide in the fine particulate matter are negatively correlated with the ozone concentration, which is positively correlated with ozone concentration and is tested by significance. Atmospheric discharge (thunderstorm) can produce a considerable amount of air anion. Air negative ions are an important indicator of air quality, which is of great significance to the living environment. The distribution of negative ions in the study space and its influencing factors in order to provide a basis for air quality assessment in the region and provide references for the long-term research on air anion in different urban areas. 展开更多
关键词 ECOLOGICAL Environment NEGATIVE Air Ion DISTRIBUTION characteristics correlation COEFFICIENT
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