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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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参照群体与社会关系的双重性——县域教师家长教育期望底层逻辑的一个社会学解释
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作者 董永贵 王倩兮 《当代教育与文化》 2026年第1期91-98,共8页
县域教育是乡村振兴的重要环节,承载着基础教育公平与质量提升的双重使命。县域教师家长的双重身份使其教育期望呈现独特样态。本研究通过对10组教师家长及其子女的半结构化访谈深入探究该议题。研究发现,县域教师家长的教育期望呈现“... 县域教育是乡村振兴的重要环节,承载着基础教育公平与质量提升的双重使命。县域教师家长的双重身份使其教育期望呈现独特样态。本研究通过对10组教师家长及其子女的半结构化访谈深入探究该议题。研究发现,县域教师家长的教育期望呈现“互为参照群体”的双重表征,其社会关系的双重性也使教育行动呈现双重性。其教育期望底层逻辑具体表现为互为参照群体下期许“别人家孩子”的隐形竞赛、道德凝视中“模范家庭”的自我规训与焦虑传导、地域性社会资本运作的优质资源攫取与信息利用、弱关系网络匮乏的体制执念偏好与眼界发展受限,以及亲子关系角色失调与情感耗竭的学业辅导困境。 展开更多
关键词 教育期望 县域教师家长 参照群体 社会关系
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基于CNN-LSTM的中小河流水位预报模型研究——以崩坎水红饶站为例
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作者 刘玉 刘志伟 《广东水利水电》 2026年第2期54-63,共10页
为解决无流量资料地区的中小河流洪水水位预报问题,该文提出一种融合卷积神经网络(CNN)与长短期记忆网络(LSTM)的洪水预报模型,通过整合流域内降雨序列的时空分布特征与水位时序演变规律,找出降雨-水位的非线性映射关系,构建降雨-水位... 为解决无流量资料地区的中小河流洪水水位预报问题,该文提出一种融合卷积神经网络(CNN)与长短期记忆网络(LSTM)的洪水预报模型,通过整合流域内降雨序列的时空分布特征与水位时序演变规律,找出降雨-水位的非线性映射关系,构建降雨-水位洪水预报模型。以龙江支流崩坎水为研究区域进行实验,结果表明,该模型在无流量资料的情况下,短临水位预报能够取得较好的效果,在6 h预见期内保持较高的预测精度(确定性系数为0.82)。该研究为洪水水位预报工作提供了一种新的解决思路,能够进一步提高无资料地区水位预报的精度。 展开更多
关键词 CNN-LSTM 时空特征融合 雨量-水位关系 中小河流 洪水预报
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三峡水库调蓄与水位流量关系变化对长江枝城段水位影响的定量分析
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作者 杨淮水 杜涛 +3 位作者 曾凌 王一寒 江聪 李祖忠 《中国农村水利水电》 北大核心 2026年第2期84-90,共7页
三峡水库运行后,受水库调蓄及河床冲刷等因素影响,长江中游枝城站水位受到较大影响,为讨论三峡水库调蓄与水位流量关系变化对枝城站水位的影响,结合GR4J模型、马斯京根河道汇流算法重构了枝城水文站不受三峡水库调蓄影响的径流与水位过... 三峡水库运行后,受水库调蓄及河床冲刷等因素影响,长江中游枝城站水位受到较大影响,为讨论三峡水库调蓄与水位流量关系变化对枝城站水位的影响,结合GR4J模型、马斯京根河道汇流算法重构了枝城水文站不受三峡水库调蓄影响的径流与水位过程,利用控制变量法设置3种模拟情景,对水位变化进行定量归因。结果表明:三峡水库运行后,枝城站流量与水位趋势变化存在一定的非同步性,夏季、秋季和年均水位较于相应的流量呈现更为显著的下降趋势,而春季与冬季水位的上升趋势性明显弱于相应流量;受河床侵蚀下切影响,枝城站水位-流量关系发生改变,导致相同流量对应的水位存在不同程度的下降;枝城站在2003-2019年间水位下降了0.36 m,其中99.7%归因于河床侵蚀下切引起的水位-流量关系变化,三峡水库调蓄影响仅使得水位下降0.01 m。季节尺度上,秋季水位降幅最大,达到了1.01 m,水位-流量关系变化与三峡水库调蓄分别贡献45%和55%的降幅;在春、冬季水库补水虽然使得水位抬升0.24~0.38 m,但被水位流量关系变化导致的水位下降完全抵消。三峡水库调蓄对春秋冬三个季节水位存在显著变化,在蓄水前期(2003-2008年)的影响量分别为-0.21 m、0 m和-0.2 m,进入正常运行期(2009-2019年)后影响量分别变化至0.24、0.38和-0.6 m。研究有助于全面认识三峡水库调蓄对枝城站水位的影响,揭示枝城河段水位演化的成因机制。 展开更多
关键词 三峡水库 枝城河段 水位 水位-流量关系变化 定量归因
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Fragility Curves of Existing RC Buildings Based on Specific Structural Performance Levels 被引量:3
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作者 Marco Vona 《Open Journal of Civil Engineering》 2014年第2期120-134,共15页
In seismic risk mitigation policies, fragility functions of existing buildings play a fundamental role. In this paper, a procedure to develop analytical fragility curves for Moment Resisting Frame Reinforced Concrete ... In seismic risk mitigation policies, fragility functions of existing buildings play a fundamental role. In this paper, a procedure to develop analytical fragility curves for Moment Resisting Frame Reinforced Concrete buildings is presented. The design of the selected building typologies was performed according to the codes at the time of construction using force-based methods and the state of the practice at the time of construction. A total of 216 building classes were defined, considering different ages, number of storeys, infill panels, plan dimensions, beam stiffness, and concrete strength. The investigated buildings can be considered low-engineered buildings, using no seismic codes or old seismic codes. The seismic capacity of the selected models representing the existing RC buildings has been evaluated through non-linear dynamic simulations. Seismic response has been analyzed, considering various peak and integral intensity measures and various response parameters, such as ductility demands and Interstorey Drift Ratio (IDR). A new relationship among structural performance, damage levels and interstorey drift ratios for each studied type is introduced, which is calibrated using the damage levels described in EMS98. It is important to highlight that in this study, different thresholds of IDR have been associated with different typologies, considering their different ductility member levels after their different structural responses. Fragility Curves (FCs) for the studied structural types are set up, developed and discussed. 展开更多
关键词 Existing RC Buildings Building DAMAGE CRITERIA FRAGILITY CURVES STRUCTURAL Performance—Damage levelS relationship
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Pore-scale simulation of coupled reactive transport and dissolution in fractures and porous media using the level set interface tracking method 被引量:1
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作者 Huang Hai Li Xiao-Yi 《南京大学学报(自然科学版)》 CAS CSCD 北大核心 2011年第3期235-251,共17页
关键词 英文摘要 内容介绍 编辑工作 期刊
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基于降雨—水位涨幅关系的典型平原河网区实时水位预报模型
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作者 朱立国 朱静 +1 位作者 张小稳 徐兴 《水电能源科学》 北大核心 2025年第11期21-24,共4页
为构建一种适用于典型平原河网区简便可靠的实时水位预报模型,以无锡市特定区域为例,收集苏南运河无锡站2015~2024年的实测小时水位及区域面雨量数据,采用水文统计学方法,明确了区域代表站点的降雨—水位涨幅线性关系,并试算出以水位为... 为构建一种适用于典型平原河网区简便可靠的实时水位预报模型,以无锡市特定区域为例,收集苏南运河无锡站2015~2024年的实测小时水位及区域面雨量数据,采用水文统计学方法,明确了区域代表站点的降雨—水位涨幅线性关系,并试算出以水位为表征量的汇流单位线。基于此构建实时水位预报模型,输入小时预报降雨过程,预报场次降雨洪峰水位、峰现时间。经2024年3场次降雨水位过程验证,所建模型能较好地模拟水位上涨过程,预报结果准确可靠,在基层防汛工作中有较强的适用性,也为其他水力条件相似平原河网区水位预报模型构建提供了借鉴。 展开更多
关键词 典型平原河网区 降雨—水位涨幅关系 汇流单位线 实时水位预报
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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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Is HOMO Energy Level a Good Parameter to Characterize Antioxidant Activity 被引量:1
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作者 Hong Yu ZHANG De Zhan CHEN 《Chinese Chemical Letters》 SCIE CAS CSCD 2000年第8期727-730,共4页
Semiempirical quantum chemical method AM1 was employed to calculate the highest occupied molecular orbital (HOMO) energy levels (E-HOMO) for various types of antioxidants. It was verified that the correlation between ... Semiempirical quantum chemical method AM1 was employed to calculate the highest occupied molecular orbital (HOMO) energy levels (E-HOMO) for various types of antioxidants. It was verified that the correlation between logarithm of free radical scavenging rate constants (1gks) and E-HOMO substantially arises from the correlation between E-HOMO and O-H bond dissociation energies (BDE) of antioxidants. Furthermore, E-HOMO were poorly correlated with the logarithm of relative free radical scavenging rate constants (1gk(3)/k(1)) for various types of antioxidants that possess complex structures (r = 0.5602). So in a broad sense, E-HOMO was not an appropriate parameter to characterize the free radical scavenging activity of antioxidants. 展开更多
关键词 AM1 ANTIOXIDANT free radical HOMO energy level O-H bond dissociation energy structure-activity relationship
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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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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 被引量:1
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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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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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水位—流量关系曲线拟合方法对比分析
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作者 周正道 黄斌 +1 位作者 普祥和 李云霞 《中国防汛抗旱》 2025年第12期98-102,共5页
水位—流量关系曲线的拟合是水文资料整编工作中的重要环节,其精度直接影响资料整编成果的质量。随着水文现代化发展,水文站点数量急剧增加,传统的人工定线方法难以满足工作需求。为提高水文资料整编质量,综合对比分析最小二乘法、规划... 水位—流量关系曲线的拟合是水文资料整编工作中的重要环节,其精度直接影响资料整编成果的质量。随着水文现代化发展,水文站点数量急剧增加,传统的人工定线方法难以满足工作需求。为提高水文资料整编质量,综合对比分析最小二乘法、规划求解、正交函数拟合曲线的精度与结果,结果表明:正交函数拟合结果优于规划求解与最小二乘法,该方法可快速实现水位—流量关系曲线的拟合,不仅便于计算机分析处理,而且消除了人为主观性,无需人工干预。正交函数拟合曲线能满足水文资料整编要求,可提高工作效率和定线精度,具有推广应用价值。 展开更多
关键词 水位—流量关系 优选 最小二乘法 规划求解 正交函数
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