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Hair Mercury Levels and Their Relationship with Seafood Consumption among Preschool Children in Shanghai 被引量:1
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作者 YAN Jin GAO Zhen Yan +1 位作者 WANG Ju YAN Chong Huai 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2017年第3期220-223,共4页
Mercury is a global pollutant. Children are vulnerable to environmental toxicants. Seafood consumption is a major source of methylmercury exposure. In order to ascertain children’s mercury exposure levels and study t... Mercury is a global pollutant. Children are vulnerable to environmental toxicants. Seafood consumption is a major source of methylmercury exposure. In order to ascertain children’s mercury exposure levels and study their relationship with seafood consumption, we conducted a cross-sectional study among preschool children in Shanghai. 展开更多
关键词 high Hair Mercury levels and Their relationship with Seafood Consumption among Preschool Children in Shanghai
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Relationship of serum GDF11 levels with bone mineral density and bone turnover markers in postmenopausal Chinese women 被引量:3
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作者 Yusi Chen Qi Guo +7 位作者 Min Zhang Shumin Song Tonggui Quan Tiepeng Zhao Hongliang Li Lijuan Guo Tiejian Jiang Guangwei Wang 《Bone Research》 SCIE CAS CSCD 2016年第1期55-59,共5页
Growth differentiation factor 11 (GDF11) is an important circulating factor that regulates aging. However, the role of GDF11 in bone metabolism remains unclear. The present study was undertaken to investigate the re... Growth differentiation factor 11 (GDF11) is an important circulating factor that regulates aging. However, the role of GDF11 in bone metabolism remains unclear. The present study was undertaken to investigate the relationship between serum GDF11 level, bone mass, and bone turnover markers in postmenopausal Chinese women. Serum GDF11 level, bone turnover biochemical markers, and bone mineral density (BMD) were determined in 169 postmenopausal Chinese women (47-78 years old). GDF11 serum levels increased with aging. There were negative correlations between GDF11 and BMD at the various skeletal sites. After adjusting for age and body mass index (BMI), the correlations remained statistically significant. In the multiple linear stepwise regression analysis, age or years since menopause, BMI, GDF11, and estradiol were independent predictors of BMD. A significant negative correlation between GDF11 and bone alkaline phosphatase (BAP) was identified and remained significant after adjusting for age and BMI. No significant correlation was noted between cross-linked N-telopeptides of type I collagen (NTX) and GDF11. In conclusion, GDF11 is an independent negative predictor of BMD and correlates with a biomarker of bone formation, BAP, in postmenopausal Chinese women. GDF11 potentially exerts a negative effect on bone mass by regulating bone formation. 展开更多
关键词 GDF bone relationship of serum GDF11 levels with bone mineral density and bone turnover markers in postmenopausal Chinese women BMD
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Relationship between glutathione and malonaldehyde levels in erythrocytes and the deformation index of erythrocyte in patients at various periods following acute cerebral infarction 被引量:2
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作者 Dongjun Zhang Guangrun Xu +1 位作者 Zhaofu Chi Bingxia Shi 《Neural Regeneration Research》 SCIE CAS CSCD 2006年第1期64-66,共3页
BACKGROUND: Glutathione, as an in vivo free radical scavenger, plays an important role in the anti-oxidation defense mechanism in patients with acute cerebral infarction. OBJECTIVE: To observe the relationship betwe... BACKGROUND: Glutathione, as an in vivo free radical scavenger, plays an important role in the anti-oxidation defense mechanism in patients with acute cerebral infarction. OBJECTIVE: To observe the relationship between the levels of glutathione (GSH) and malonaldehyde (MDA), the metabolite of lipid peroxidation, in erythrocyte and deformation index of erythrocyte in patients at various periods following acute cerebral infarction. DESIGN: Controlled observation.SETTING: Qilu Hospital of Shandong University and Institute of Cerebrovascular Disease of Qingdao Medical College. PARTICIPANTS: We chose 98 inpatients with acute cerebral infarction from Department of Neurology, Qilu Hospital of Shandong University from January to December 2000 , serving as cerebral infarction group, including 50 male and 48 female, with mean age of (62±7)years. There were 23 cases found on the 1^st day after onset; 25 cases on the 3^rd day after onset; 25 cases on the 7^th day after onset; 25 cases on the 14th days after onset, and they were all confirmed by craniocerebral CT or MRI. Another 30 homeochronous inpatients with neurosis, cervical syndrome, lumbar intervertebral disc herniation and motor neuron disease were chosen as control group, including 20 male and 10 female, with mean age of (52±8)years . There was no significant difference in age and gender distribution between two groups (P 〉 0.05). Patients in the two groups were informed of detected index.METHODS:①Ulnar venous blood was chosen from the patients who were fasted on the 1^st, 3^rd,7^th and 14^th days after onset. Deformation index of erythrocyte was measured with BL88-CKX laser diffraction erythrocyte deformeter and photographing was performed. GSH level in erythrocyte was measured with DTNB assay introduced by Beu-tler. MDA level in erythrocyte was measured with modified thiobarbituric acid colorimetric method.②At each sample collecting , according to the criteria accepted by the Fourth National Conference of Cerebrovascular Disease, intergrant of neurologic impairment 〈 15 points was regarded as mild (n=46), 15 to 30 points as moderate (n=40)and, 〉 30 points as severe (n=12). ③ t test was used to compare data between two groups , and linear correlation analysis was used in relationship analysis among indexes. MAIN OUTCOME MEASURES :① Comparison of erythrocyte GSH and MDA levels and deformation index of erythrocyte at various periods between patients with acute cerebral infarction and controls. ②Correlation of erythrocyte GSH level with erythrocyte MDA level and with deformation index of erythrocyte in patients with cerebral infarction . ③ Relationship between erythrocyte GSH level and severity of disease in patients with acute cerebral infarction. RESULTS: Totally 98 patients with acute cerebral infarction and 30 controls all entered the stage of result analysis. ① Erythrocyte GSH level and deformation index of erythrocyte were lower on the 1^st, 3^rd, 7^th and 14^th days after onset in cerebral infarction group than in control group (P 〈 0.05-0.01), and erythrocyte MDA level was significantly higher in cerebral infarction group than in control group (P 〈 0.05-0.01). The three indexes changed most significantly on day 3 after onset in patients, and began to recover or decrease on day 7 after onset and inclined to be normal on day 14 after onset. ② Erythrocyte GSH level was significantly negatively correlated with erythrocyte MDA level in patients with acute cerebral infarction on the 1^st, 3^rd, 7^th and 14^th days after onset (r=-0.534, -0.713, -0.645, -0.656, respectively, P 〈 0.05-0.01 ) ,and significantly positively correlated with erythrocyte deformation index (t-=0.502, 0.560, 0.455, 0.504, respectively, P 〈 0.05). ③Erythrocyte GSH level was significantly lower in moderate or severe patients with acute cerebral infarction than in mild patients[(0.215±0.088),(0.192±0.102), (0.281±0.090) g/L, P〈 0.05]. CONCLUSION:①Erythrocyte GSH and MDA levels and deformation index of erythrocyte change significantly on the 3^rd day following acute cerebral infarction. Index detection results gradually tended to be normal on from the 7^th day to 14^th days day after onset. ② Change of erythrocyte GSH level can reflect the severity of disease of patients with acute cerebral infarction.③Decrease of erythrocyte GSH level in patients with acute cerebral infarction is one of reasons that result in the decrease of deformation ability of erythrocyte. 展开更多
关键词 relationship between glutathione and malonaldehyde levels in erythrocytes and the deformation index of erythrocyte in patients at various periods following acute cerebral infarction
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A PRELIMINARY STUDY ON THE RELATIONSHIP BETWEEN MURINE IgE LEVEL AND 3-METHYL-CHOLANTHRENE INDUCED FIBROSARCOMA
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作者 张克 郑珊珊 吴安然 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 1990年第3期42-45,共4页
The relationship between murine IgE, IgG, and IgG1 level and birosarcoma induced by 3-Methyl-cholanthrene in NIH mice was studied. The results showed that IgE, IgG or IgGl had no significant effect on tumor incidence;... The relationship between murine IgE, IgG, and IgG1 level and birosarcoma induced by 3-Methyl-cholanthrene in NIH mice was studied. The results showed that IgE, IgG or IgGl had no significant effect on tumor incidence; the high IgE level could extend the survival time of 3-Methylcholanthrene injected mice (P<0.05) and survival time of tumor bearing mice (P<0.01), while IgG or IgGl could not. The data from this study did not show that IgE, IgG or IgGl had any significant effect on the tumor size and the tumor growth rate. The probable mechanism involved was discussed. 展开更多
关键词 IGE high NS A PRELIMINARY STUDY ON THE relationship BETWEEN MURINE IgE level AND 3-METHYL-CHOLANTHRENE INDUCED FIBROSARCOMA IgG
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Relationship between changes of endogenous ABA level and resistance in hybrid rice under temperature stress 被引量:1
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作者 Li Ling ,Fu Chong,and GUO Shao chuan,Xiangtan Teachers College ,Hunan 411201,China 《Chinese Rice Research Newsletter》 1994年第1期9-9,共1页
We studied the relationship between endogenous ABA and resistance to temperature stress in seedlings of hybrid rice. The hybrid rice Combinations Shanyou 63, Shanyou 287, Weiyou 63, and Weiyou 287 were treated under 2... We studied the relationship between endogenous ABA and resistance to temperature stress in seedlings of hybrid rice. The hybrid rice Combinations Shanyou 63, Shanyou 287, Weiyou 63, and Weiyou 287 were treated under 2℃ and 42℃ respectively for 48 h. Endogenous ABA concentrations were obtained by gas chromatography with electron capture detector (GC-ECD) and a nickel labelled external standard. Leakage of electrolytes were determined. At optimal temperature (27℃), there was difference between the level of endogenous ABA and the leakage of electrolytes in hybrid rice combinations, which attributed to genetic difference. ABA level in Weiyou system was higher than that in Shanyou, and there were distinctions between Shanyou system itself (see table). At 2℃, the ABA content of rice seedling was increased. ABA level of Weiyou system maintained higher than Shanyou system at 27℃. The leakage quantities of 展开更多
关键词 ABA relationship between changes of endogenous ABA level and resistance in hybrid rice under temperature stress
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THE RELATIONSHIP BETWEEN THE ERYTHROCYTE POLYAMINE LEVELS AND THE DIFFERENT TYPES OF LEUKEMIA
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作者 缪金明 欧阳仁荣 潘瑞彭 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 1991年第1期69-72,共4页
In a study on erythrocyte polyamine levels in 20 leukemia patients and 18 healthy individuals, following results were obtained. Putrescine(Pu) in ery-throcytes was nearly undetectable but in 2 AMoL patients; Spermidin... In a study on erythrocyte polyamine levels in 20 leukemia patients and 18 healthy individuals, following results were obtained. Putrescine(Pu) in ery-throcytes was nearly undetectable but in 2 AMoL patients; Spermidine(Spd) level in ALL was higher than the control volue (P<0.05), in AML (M1, M2) and APL the Spd level was in the range of control group (P>0.1), while that in AMoL and AMMoL was considerably lower as compared to control (P< 0.001); Spermine (Spm) level in all types of leukemia was increased (P<0.001); Spd/Spm ratio was significantly decreased, showing 1.525 in control group, 0.938 in ALL (P<0.025), 0.779 in AML (M1, M2) P< 0.01), 0.319 in APL (P<0.001) and 0.296 in AMoL & AMMoL (P<0.001), and the differences between the Spd/Spm ratio in AMoL and AMMoL and in ALL were noted (P<0.05). These results suggested that determination of erythrocyte polyamines in leukemia patients may be helpful in diagnosis, differential diagnosis and prognosis. 展开更多
关键词 THE relationship BETWEEN THE ERYTHROCYTE POLYAMINE levelS AND THE DIFFERENT TYPES OF LEUKEMIA
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A Study on the Dose-Response Relationship between Asbestos Exposure Level and Asbestosis among Workers in a Chinese Chrysotile Product Factory
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作者 J. Q. HUANG 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1990年第1期90-98,共9页
The dose-response relationship for asbestos exposure in a chrysotile product factory was studied. The past gravimetric dust concentration values, obtained from different worksites, were converted into fiber concentrat... The dose-response relationship for asbestos exposure in a chrysotile product factory was studied. The past gravimetric dust concentration values, obtained from different worksites, were converted into fiber concentration values according to conversion factors that were worked out by simultaneous sampling in this study. The conversions were made so that exposure could be expressed in fiber-years (f-yr). Asbestosis was diagnosed on the basis of chest radiographs and occupational histories. Cumulative dust exposure (f-yr) was calculated up to the date of diagnosis for asbestosis patients, and up to September 1982 for the remaining workers. A dose-response relationship expressed as fiber-years exposed vs cumulative prevalence of asbestosis was established by the life table method on the basis of these data. Predicted 3 and 1% prevalence of asbestosis corresponded to 43 and 22 f-yr exposure, respectively. Considering that a worker can work for 35 years, these doses are commensurate with dust concentrations of 1.22 and 0.63 f/ml, respectively. It is recommended that 1 f/ml be taken as the maximum allowable concentration of airborne asbestos dust for the workplace with an anticipated prevalence of about 2% asbestosis after 35 years of exposure. 1990 Academic Press, Inc. 展开更多
关键词 A Study on the Dose-Response relationship between Asbestos Exposure level and Asbestosis among Workers in a Chinese Chrysotile Product Factory
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鄱阳湖大湖池与修河的河湖关系分析
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作者 陈明华 徐志文 +2 位作者 龚磊强 罗浩 刘恋 《环境监测管理与技术》 北大核心 2025年第1期36-41,共6页
通过对2010年、2013年、2014年、2021年和2022年鄱阳湖大湖池和修河的日水位实测数据进行分析,研究大湖池与修河的河湖关系。结果表明:修河吴城站水位高于16.36 m呈现“高水似湖”,低于16.36 m呈现“低水似碟及低水似河”;水位为10.36 m... 通过对2010年、2013年、2014年、2021年和2022年鄱阳湖大湖池和修河的日水位实测数据进行分析,研究大湖池与修河的河湖关系。结果表明:修河吴城站水位高于16.36 m呈现“高水似湖”,低于16.36 m呈现“低水似碟及低水似河”;水位为10.36 m~16.36 m时,大湖池的水位变化由闸口人为控制,大湖池与修河隔离(2013年、2014年)或连通(2010年、2021年、2022年)取决于修河水位与闸口控制水位的高低;大湖池与修河年内月平均水位值均表现为1月—7月逐月升高,8月—12月逐月降低,大湖池最低水位为湖底高程即大湖池干涸,修河最低水位每年不同且持续降低。 展开更多
关键词 水位 河湖关系 碟形湖 大湖池 修河 鄱阳湖
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城市建成环境与轨道交通车站组团客流关系研究
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作者 刘军 罗维嘉 许心越 《华南理工大学学报(自然科学版)》 北大核心 2025年第8期1-10,共10页
准确刻画建成环境与城市轨道交通客流间的作用关系是掌握客流需求的重要前提。针对站间OD研究数据不完备、多维稀疏的问题,提出一种基于车站组团的建成环境与客流间映射关系研究方法,以实现组团OD的精准分析。首先,基于自然地理特性“... 准确刻画建成环境与城市轨道交通客流间的作用关系是掌握客流需求的重要前提。针对站间OD研究数据不完备、多维稀疏的问题,提出一种基于车站组团的建成环境与客流间映射关系研究方法,以实现组团OD的精准分析。首先,基于自然地理特性“以团代点”,考虑客流去向特征,计算团间相似度,形成两层的组团划分方法,解决数据稀疏的问题;其次,从O/D组团的吸引能力、OD可达性特征两个维度构造建成环境指标体系及建成环境描述方法;然后,提出一种基于梯度提升回归树(GBDT)模型的刻画建成环境特征和客流之间关系的方法,分析单因素对于客流的影响强度及阈值;最后,以北京地铁为例验证。结果表明:建成环境与轨道交通车站组团间客流存在时空异质性、非线性特征及阈值效应;组团的研究视角有效解决了数据稀疏的问题;OD阻抗特征是影响客流的首要特征,解释度高达38.40%;人口经济特征是次要影响因素,且存在显著的阈值效应。因此,在城市轨道交通规划的过程中,首先要着重关注网络拓扑,优化交通可达性,进而深入考量区域经济活动的影响。研究结果为轨道交通规划者提供定量的分析工具,可以帮助规划者确定建成环境指标的有效范围、调整空间,为提升轨道交通运营效能提供参考。 展开更多
关键词 城市轨道交通 建成环境 梯度提升回归树模型 组团OD客流 非线性关系
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宜居宜业和美乡村建设与城镇化的交互逻辑及实践探索
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作者 周为 蒋济蔚 《生态经济》 北大核心 2025年第8期123-135,共13页
论文立足于宜居宜业和美乡村与城镇化的基本内涵及战略背景,构建细致完整的宜居宜业和美乡村建设与城镇化水平评价指标体系,采用CRITIC权重法从全国、省域来测度2017—2021年宜居宜业和美乡村建设和城镇化水平的变动,并借助核密度估计... 论文立足于宜居宜业和美乡村与城镇化的基本内涵及战略背景,构建细致完整的宜居宜业和美乡村建设与城镇化水平评价指标体系,采用CRITIC权重法从全国、省域来测度2017—2021年宜居宜业和美乡村建设和城镇化水平的变动,并借助核密度估计、耦合协调模型和PVAR模型分别揭示两者的时空特征、共生与互动关系,得到以下结论:2017—2021年全国宜居宜业和美乡村建设与城镇化水平在整体上有所提升;省域存在明显不平衡现象;两者耦合协调程度较好,展现城乡之间良性共生发展;宜居宜业和美乡村建设和城镇化之间均产生正向的互动效应,且城镇化对宜居宜业和美乡村建设的互动影响更强。这一研究对促进城乡融合,实现我国现代化目标具有重要的参考意义。 展开更多
关键词 宜居宜业和美乡村 城镇化水平 互动关系 CRITIC权重法 PVAR模型
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团队层领导-成员交换关系与员工工作绩效:团队共享心智模型和任务互依性的作用
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作者 杨晓 陈冬丽 刘知 《心理科学》 北大核心 2025年第3期673-685,共13页
团队层领导-成员交换关系(TLMX)是团队中领导-成员交换关系(LMX)的总质量或集中趋势。学界发现TLMX能够促进员工的角色外行为,却未考察对组织能够产生直接影响的角色内行为—工作绩效。基于社会信息加工理论,研究探索了TLMX对员工工作... 团队层领导-成员交换关系(TLMX)是团队中领导-成员交换关系(LMX)的总质量或集中趋势。学界发现TLMX能够促进员工的角色外行为,却未考察对组织能够产生直接影响的角色内行为—工作绩效。基于社会信息加工理论,研究探索了TLMX对员工工作绩效的直接影响,以及团队共享心智模型的中介作用和团队任务互依性的调节作用。使用Mplus对三个时点78个团队和328名员工的配对数据分析后发现:(1)TLMX分别对团队共享心智模型和工作绩效具有正向影响;(2)团队共享心智模型在TLMX和工作绩效间具有完全中介作用;(3)团队任务互依性越高,越削弱TLMX对工作绩效的正向影响。 展开更多
关键词 团队层领导-成员交换关系 工作绩效 团队共享心智模型 任务互依性
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回水顶托效应下巨型水电站下游水位预测研究
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作者 彭旺 姚华明 +1 位作者 蒋志强 曹辉 《水电能源科学》 北大核心 2025年第9期203-207,共5页
水电站的尾水水位是计算机组出力的重要参数,当存在下游水库顶托影响时,电站尾水的设计曲线与实际观测值往往存在较大误差,增加了机组出力—流量的计算误差。为此,根据最新历史观测数据,分析了BHT水电站尾水水位与其出库流量及下游水库... 水电站的尾水水位是计算机组出力的重要参数,当存在下游水库顶托影响时,电站尾水的设计曲线与实际观测值往往存在较大误差,增加了机组出力—流量的计算误差。为此,根据最新历史观测数据,分析了BHT水电站尾水水位与其出库流量及下游水库XLD顶托水位的关系,建立了基于多情景划分的贝叶斯优化-长短期记忆网络(BO-LSTM)预测模型,并分析了调峰和泄洪工况下模型的应用效果。结果表明,XLD水位高于585m后对BHT电站的尾水水位有显著的顶托影响。相比于水位—流量曲线和非线性曲线拟合方法,基于多情景划分的BO-LSTM模型在精度上有显著提升,平均绝对误差(MMAE)降低了68.1%。BO-LSTM模型在多种工况下均能更准确地捕捉水位的起伏变化过程。研究结果对水电站精细化调度具有重要意义。 展开更多
关键词 水位—流量关系 顶托影响 长短期记忆神经网络 预测
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基于星载光子LiDAR数据的水位估算研究——以丹江口水库为例
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作者 黄玉帅 王成 +1 位作者 王宏涛 杨智翔 《遥感技术与应用》 北大核心 2025年第2期454-460,共7页
水库尤其是大型水库水位是洪水预警和蓄水调度的重要数据。以丹江口水库为例,利用2018~2022年的星载光子计数激光雷达(ICESat-2/ATLAS)的ATL13数据,通过提取其中包括经纬度、大地高及大地水准面差距等相关参数,从而获得水位信息并利用... 水库尤其是大型水库水位是洪水预警和蓄水调度的重要数据。以丹江口水库为例,利用2018~2022年的星载光子计数激光雷达(ICESat-2/ATLAS)的ATL13数据,通过提取其中包括经纬度、大地高及大地水准面差距等相关参数,从而获得水位信息并利用水文站观测数据进行精度验证,在无实测数据的情况下获得了高精度的水位数据。然后顾及水域面积、温度等因素,利用逐步回归及多元线性回归构建面积—水位关系模型,实现丹江口水库连续多年的水位估算。结果表明:①丹江口水库水位具有明显的季节性特征;②利用实测水位验证本文方法提取的水位精度,平均误差为0.03 m、R^(2)=0.999;③三次多项式模型建立的面积—水位关系曲线拟合精度最好,R^(2)=0.956、MAE=0.009 m。说明星载光子技术激光雷达为大型水库水位估算以及动态变化研究提供了科学数据支持。 展开更多
关键词 星载光子LiDAR 水库水位 面积-水位关系 丹江口水库
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工业经济发展与环境污染水平耦合协调关系及影响因素——以云南省为例 被引量:1
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作者 樊艳翔 雷社平 +1 位作者 贺灿飞 李文韬 《干旱区资源与环境》 北大核心 2025年第2期1-13,共13页
经济与环境协调发展问题是国内外可持续发展的关键性问题,近年来我国工业发展的区域性转移与扩散对工业经济与环境的协调发展提出了更高的要求。当前云南省正处于工业经济高速发展阶段,深入探究云南省的工业经济与环境的协调发展问题具... 经济与环境协调发展问题是国内外可持续发展的关键性问题,近年来我国工业发展的区域性转移与扩散对工业经济与环境的协调发展提出了更高的要求。当前云南省正处于工业经济高速发展阶段,深入探究云南省的工业经济与环境的协调发展问题具有深刻研究价值。基于此,文中使用层次分析法、熵权法与博弈论组合赋权法考虑主观与客观两个层面对云南省环境污染水平进行了综合性测度,同时引入耦合协调发展水平模型分析云南省工业经济与环境的耦合协调发展状态。并引入了机器学习Catboost模型在对云南省工业经济增长与环境污染耦合协调关系的主导影响因素进行识别,在此基础上对主导影响因素进行偏效应分析。研究发现:1)研究期内,云南省各地区在早期工业经济发展与环境之间存在失调发展状态,但这种失调状态都主要集中于2008年-2011年和2008年-2014年两个时间段。近年来各地区整体均向着良好的发展趋势转变,不断向更高程度的耦合协调发展状态跃进。2)耦合协调发展水平整体呈现着中间高,四周低的空间分布格局,由此也提醒有关部门需要及时注意云南省边境地区的发展问题,充分利用好边境的区位优势,促进云南边境地区持续健康发展。3)交通运输水平、对外开放水平、人口集聚水平、地区供水能力、财政投入水平对云南省工业经济与环境污染耦合协调发展起着主导作用。 展开更多
关键词 云南省 工业经济发展 环境污染水平 耦合协调关系
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中国畜牧养殖资源环境压力:时空分异特征及其与畜牧产出水平的耦合协调关系 被引量:4
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作者 张俊华 肖海峰 《中国农业大学学报》 北大核心 2025年第1期276-292,共17页
为准确测算中国畜牧养殖资源环境压力,并揭示其时空分异特征及其与畜牧产出水平的关系,采用空间自相关和耦合协调模型从时空角度揭示其演变特征、空间自相关性及其与畜牧产出水平的耦合协调关系。结果表明:1)我国畜牧养殖资源环境压力... 为准确测算中国畜牧养殖资源环境压力,并揭示其时空分异特征及其与畜牧产出水平的关系,采用空间自相关和耦合协调模型从时空角度揭示其演变特征、空间自相关性及其与畜牧产出水平的耦合协调关系。结果表明:1)我国畜牧养殖资源环境压力呈波动增长态势,多数省份处于承压状态,畜产品主产区中冀吉鲁豫湘等处于高压力,黑皖鄂处于中等压力;2)畜牧养殖资源环境压力的空间集聚特征逐渐增强,主产区中冀辽豫鄂湘地区为高-高集聚,蒙黑川地区为低-高集聚,皖鲁地区为高-低集聚;3)畜牧养殖资源环境压力与畜牧产出水平间的耦合度呈增长趋势,多数地区的耦合度均提升,但冀鲁豫地区的耦合度出现下降,且大多数地区的耦合协调度长期处于一般协调阶段。因此,加强畜牧养殖水土草粮等资源管理以提高资源利用效率,推广应用畜牧养殖废弃物资源化利用和降碳技术将有助于促进资源环境约束条件下畜牧业生产的稳定可持续发展。 展开更多
关键词 畜牧业 资源环境压力 时空演变分析 产出水平 空间自相关 耦合协调关系
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永丰水文站水位流量关系曲线率定分析 被引量:1
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作者 曹熹 《黑龙江环境通报》 2025年第2期18-20,共3页
本文对永丰断面渠道水位—流量关系曲线率定进行分析,为水旱灾害防治、中小河流治理和生态环境保护等工作提供水文信息和监测数据,并为经济社会发展和生态保护提供科学支撑。该工作有利于解决上下游、左右岸、各用水主体之间的用水矛盾... 本文对永丰断面渠道水位—流量关系曲线率定进行分析,为水旱灾害防治、中小河流治理和生态环境保护等工作提供水文信息和监测数据,并为经济社会发展和生态保护提供科学支撑。该工作有利于解决上下游、左右岸、各用水主体之间的用水矛盾,很大程度上降低水资源的管理难度,从而对构建和谐用水秩序、构建和谐社会发挥重要作用,对缓解石羊河流域尖锐的水资源供需矛盾以及对流域内建设节水型社会等都具有重要意义。 展开更多
关键词 水位流量 关系曲线 率定分析 渠道断面
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学龄儿童基本运动技能与体质健康、身体活动水平关系的研究
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作者 陈君 汪晓赞 《体育研究与教育》 2025年第2期53-58,共6页
目的:探讨学龄儿童基本运动技能与体质健康、身体活动水平的关系。方法:运用大肌肉动作发展测评工具(TGMD-3)、《国家学生体质健康标准(2014年版)》、儿童青少年身体活动水平问卷对小学三至六年级470名学生(男生223人,女生247人)的基本... 目的:探讨学龄儿童基本运动技能与体质健康、身体活动水平的关系。方法:运用大肌肉动作发展测评工具(TGMD-3)、《国家学生体质健康标准(2014年版)》、儿童青少年身体活动水平问卷对小学三至六年级470名学生(男生223人,女生247人)的基本运动技能、体质健康和身体活动水平进行调查。运用SPSS统计软件进行数据分析,并用Bootstrap法分析变量之间预测关系及中介效应。结果:学龄男童的基本运动技能尤其是操控性技能、身体活动水平高于女童(P<0.05),但学龄女童的体质健康高于男童(P<0.05);学龄儿童基本运动技能显著预测身体活动水平(β=0.0951,P<0.001),学龄儿童基本运动技能显著预测体质健康(β=0.2291,P<0.001);体质健康在学龄儿童基本运动技能与身体活动水平之间具有完全中介作用。结论:学龄儿童基本运动技能与体质健康、身体活动水平具有相关关系,因此,重视学龄儿童基本运动技能的发展,有助于其体质健康和身体活动水平的提升。 展开更多
关键词 基本运动技能 体质健康 身体活动水平 儿童 关系
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稳定封冻期河流流量预测研究综述
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作者 庞博 戴长雷 +1 位作者 邢金正 孙腾 《东北水利水电》 2025年第8期15-18,71,共5页
冰期河流流量预测对于优化水利工程设计与提升水资源管理效能具有深远的战略意义。本文从稳封期资料整编与适用条件、水流计算方法及优缺点两方面,梳理归纳稳封期流量预报相关科学研究进展。针对冰期水文观测数据相对匮乏,在不同情况下... 冰期河流流量预测对于优化水利工程设计与提升水资源管理效能具有深远的战略意义。本文从稳封期资料整编与适用条件、水流计算方法及优缺点两方面,梳理归纳稳封期流量预报相关科学研究进展。针对冰期水文观测数据相对匮乏,在不同情况下探寻适用于稳封期水位-流量推求的方法;针对稳封期水流参数确定复杂,研究根据经验或实测数据取值的差异性及模拟结果的可靠性与通用性。目前,对于稳封期水流预测,建议多选择两种或多种技术结合的方法进行,预测方法的选择还需根据研究区域的具体情况综合选定。 展开更多
关键词 稳定封冻期 水位-流量关系 预测方法 资料整编 圣维南原理
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融合图卷积网络和本体信息的电力通信网文档级关系抽取研究
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作者 钱玲飞 马子宜 +2 位作者 董嘉嘉 朱鹏宇 高德荃 《数据分析与知识发现》 北大核心 2025年第6期63-72,共10页
【目的】提升电力通信系统故障文本的关系抽取性能,针对领域特点,提出一种考虑本体信息的多层次图卷积文档级关系抽取模型。【方法】首先,使用字级别嵌入对故障文本进行编码;其次,构造句级别和实体级文档图,通过卷积聚合实体级、句子级... 【目的】提升电力通信系统故障文本的关系抽取性能,针对领域特点,提出一种考虑本体信息的多层次图卷积文档级关系抽取模型。【方法】首先,使用字级别嵌入对故障文本进行编码;其次,构造句级别和实体级文档图,通过卷积聚合实体级、句子级与文档级的语义信息;最后,根据本体概念模型设计“本体-本体”边构造方法,加入“预测实体对是否符合本体约束”的辅助任务,提升模型性能。【结果】在自建的电力通信网故障文本数据集上进行消融实验和对比实验。实验结果表明:所提模型表现最优,F1、Ign_F1、Accuracy值分别达到97.22%、95.17%、97.97%。【局限】需进一步验证模型的泛化能力。【结论】所提模型适用于电力通信网故障知识图谱的关系抽取任务,较现有模型具有更好的抽取效果。 展开更多
关键词 文档级关系抽取 图卷积网络 本体信息 电力通信网 故障知识图谱
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甲状腺功能水平与肌少症相关特征表型的关联
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作者 李嘉彤 金玥 +3 位作者 刘润嘉 宋博文 朱晓倩 李念虎 《中国组织工程研究》 CAS 北大核心 2025年第6期1312-1320,共9页
背景:多项观察性研究发现甲状腺功能水平与肌少症之间存在密切关系,但是甲状腺功能水平与肌少症发病之间的因果关系尚不明确。目的:采用两样本孟德尔随机化方法研究甲状腺功能水平与肌少症的因果关系。方法:利用促甲状腺激素、游离三碘... 背景:多项观察性研究发现甲状腺功能水平与肌少症之间存在密切关系,但是甲状腺功能水平与肌少症发病之间的因果关系尚不明确。目的:采用两样本孟德尔随机化方法研究甲状腺功能水平与肌少症的因果关系。方法:利用促甲状腺激素、游离三碘甲状腺原氨酸、游离四碘甲状腺原氨酸、亚临床甲状腺功能亢进症、亚临床甲状腺功能减退症和肌少症的4种相关表型——左手握力、右手握力、四肢瘦体质量、步速的全基因组关联研究汇总数据进行两样本孟德尔随机化分析,分别采用逆方差加权法、加权中位数法、简单模式法、加权中值方法和MR-Egger回归法作为分析方法,同时采用异质性检验、多效性检验、MR-PRESSO、留一法、漏斗图等方法进行敏感性分析。结果与结论:促甲状腺激素的增高会增加左手握力(β=0.02,SE=0.01,P=0.01)、右手握力(β=0.02,SE=0.01,P=0.01),游离三碘甲状腺原氨酸的增高会降低左手握力(β=-0.06,SE=0.02,P=9.5×10^(-5))、右手握力(β=-0.07,SE=0.02,P=9.3×10^(-5)),亚临床甲状腺功能亢进症会降低步速(β=-4.4×10^(-3),SE=1.7×10^(-3),P=0.01)。敏感性分析结果与主要分析基本一致。结果表明:促甲状腺激素上升是肌少症保护因素,游离三碘甲状腺原氨酸上升和亚临床甲状腺功能亢进症可能导致肌少症发生风险增加。 展开更多
关键词 孟德尔随机化 因果关系 甲状腺功能 促甲状腺激素 游离三碘甲状腺原氨酸 肌少症
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