Soil characterization and heavy metals in different layers (0 - 15 cm;15 - 30 cm and 30 - 45 cm depth) of automobile mechanic waste dumps were studied. The soils showed remarkably high levels of all the metals above b...Soil characterization and heavy metals in different layers (0 - 15 cm;15 - 30 cm and 30 - 45 cm depth) of automobile mechanic waste dumps were studied. The soils showed remarkably high levels of all the metals above background concentrations with most (Ni, Cu, Fe, Cr and Cd) decreasing with soil depth. The distribution pattern were in the following order Fe > Cu > Zn > Pb > Cr > Ni > Cd. Across all the sampling locations and profiles, Fe and Cd showed the highest (476.4 μg·g-1) and least (37.5 μg·g-1) mean concentrations respectively. Pollution load index (PLI) and index of geoaccumulation (Igeo) revealed overall high and moderate contamination respectively but the enrichment factors (EFs) for Pb Ni and Cd are severe. The inter-element relationship revealed the identical source of elements in the soils of the studied area. The accuracy of the results has been cheeked using the standard reference material;SRM (PACS-2). The mechanic waste dumps represent potential sources of heavy metal pollution to environment. The elevated levels of heavy metals in these soil profiles constitute a serious threat to both surface and groundwater.展开更多
When the bridge structure stability safety factor of the first type is 4, the research that whether the structure reliability index will reach target reliability index under the more-likely-to-happen collapse situatio...When the bridge structure stability safety factor of the first type is 4, the research that whether the structure reliability index will reach target reliability index under the more-likely-to-happen collapse situation of the second type is necessary. The stability calculations of the first and the second type are made respectively for single layer and single span rigid frame bridge. Based on the critical load obtained from the stability calculation of the first type, the stability safety factor of the first type is taken as 4, and the first order reliability method is used to program and calculate the reliability index. Then, the load effect under the stability reliability index cal- culation of the first type and the critical load of the second type are employed to calculate the reliability index of the second type. The evaluation of structure stability safety factor is discussed according to reliability index. Based on the discussion above, parameter analysis of the stable critical loads of two types is made, and the in- fluence of critical load change on reliability index is researched. The result shows that stability analysis should identify collapse state; when the stability safety factor of the first type is 4, but the structure has the collapse of the second type, the reliability index cannot be ensured to reach the target reliability index under certain condi- tions.展开更多
This paper presents the global solar radiation (GSR) and cloud transmittance factor (cf) measured at the horizontal surface over a period of one year from 2009 to 2010 using CMP6 Pyranometer and NILUUV Irradiance Mete...This paper presents the global solar radiation (GSR) and cloud transmittance factor (cf) measured at the horizontal surface over a period of one year from 2009 to 2010 using CMP6 Pyranometer and NILUUV Irradiance Meter at Lukla (Latitude 26.69oN,Longitude 86.73?E and Altitude 2850 m) in the foothills of the Mt Everest (8850 m high). Monthly and seasonal variations of global solar radiation as well as correlation between clearness index and cloud transmittance factor at Lukla are presented. The annual average daily global solar radiation is about 3.83 kWh/sq·m/day which is sufficient to promote solar active and passive energy technology at high mountain terrain where there is no other viable alternative sources of energy. The maximum and minimum global solar radiation of 5.33 and 2.08 kWh/sq·m/day is recorded in April and September 2010 respectively. The seasonal variation of solar energy is about 2.87 kWh/sq·m/day and 4.83 kWh/sq·m/day in summer and spring respectively which is not in line with the general trend. The coefficient of determination (R2) between cloud transmittance factor (cf) and clearness factor (K) is found to be 0.97. This novel result can be utilized to estimate the global solar radiation at the horizontal surface where K and cf are available.展开更多
BACKGROUND: Ankle brachial index (ABI) is widely involved in researches and clinical application of peripheral vascular injury of patients with diabetes mellitus (DM); however, the application in cerebral infarction (...BACKGROUND: Ankle brachial index (ABI) is widely involved in researches and clinical application of peripheral vascular injury of patients with diabetes mellitus (DM); however, the application in cerebral infarction (CI) is rare. OBJECTIVE: To investigate the possible risk factor of cerebral infarction plus peripheral arterial disease (PAD), compare metabolic characteristics of patients who having CI plus PAD or only having CI, and understand the significance of ABI on screening and diagnosing CI plus PAD of lower limb. DESIGN: Contrast observation based on CI patients. SETTING: Department of Neurology, Nanxishan Hospital of Guangxi Zhuang Autonomous Region. PARTICIPANTS: A total of 124 CI patients were selected from Department of Neurology, Nanxishan Hospital of Guangxi Zhuang Autonomous Region from July 2005 to April 2006, including 72 males and 52 females aged from 45 to 88 years. All patients met the diagnostic criteria of cerebrovascular disease established by National Academic Conference of Cerebrovascular Diseases in 1995 and determined as cerebral infarction with MRI or CT examination. All patients provided informed consent. There were 46 cases (37.2%) with CI plus PAD and 78 cases (62.8%) only with CI. METHODS: Blood pressure of bilateral ankles and upper extremities was measured at plain clinostatism with DINAMAP blood pressure monitor (GE Company). The ratio between average systolic pressure of lateral ankle and average systolic pressure of both upper extremities was regarded as ABI. The normal ABI was equal to or more than 0.9. If ABI < 0.9 occurred at one side, patients were diagnosed as PAD. On the second morning after hospitalization, blood was collected to measure fasting blood glucose (FBG), 2-hour postprandial blood glucose (PBG2h), glycosylated hemoglobin (HbA1c), triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). Among them, blood glucose, lipid and other biochemical markers were measured with enzyme chemistry assay and HbA1c was measured with HbA1c meter based on high liquid phase. Measurement data and enumeration data were compared with t test and Chi-square test, and multiple factors were dealt with Logistic regression analysis and multivariate linear regression analysis. MAIN OUTCOME MEASURES: Results of correlation between ABI and metabolic markers with multivariate linear regression analysis; risk factors of CI plus PAD with Logistic regression analysis; comparisons of metabolic markers between PAD and non-PAD patients. RESULTS: All 124 patients with acute CI were involved in the final analysis. ① Comparisons of metabolic markers: Levels of serum LDL-C and uric acid (UA) were higher of PAD patients than those of non-PAD patients (t =2.051 9, 3.339 1, P < 0.05); however, there were no significant differences among other metabolic markers (P > 0.05). ② Results of multivariate linear regression analysis: PBG2h, LDL-C and UA were obvious correlation with ABI of posterior tibial artery of lower limb and dorsal pedis artery (partial regression coefficient = -0.231 to -1.010, P < 0.05). ③ Risk factors of CI plus PAD with Logistic regression analysis: Age, smoking history, sum of CI focus (≥3) and LDL-C were independent risk factor of CI plus PAD (OR =1.524-5.422, P < 0.05-0.01). CONCLUSION: ① Levels of serum LDL-C and UA of patients with CI plus PAD are high. ② ABI of lower limbs is correlation with PBG2h, LDL-C and UA. In addition, measuring ABI is beneficial for early diagnosing PAD of lower limbs of patients who have poorly controlled blood glucose, abnormal lipid and poor renal function. ③ Age, LDL-C and sum of CI focus (≥3) are independent risk factors of CI plus PAD. It is of significance for screening non-PAD patients to evaluate risk degrees and prognosis and select therapeutic methods based on ABI measurement.展开更多
The low and slowly increasing soybean yield restricts the development of soybean production. Accurate measures of total factor productivity (TFP) for soybean production can be helpful in identifying conditions, instit...The low and slowly increasing soybean yield restricts the development of soybean production. Accurate measures of total factor productivity (TFP) for soybean production can be helpful in identifying conditions, institutions or policies that promote soybean production development in China. In this paper, TFP growth for soybean production was estimated for a panel data of 10 major soybean producing provinces from 2005 to 2017. Results reveal that TFP grew at an average rate of 1.3% over the whole period, with technical progress contributing 2.3% and efficiency change providing the other -1.0%. The change of TFP for soybean production over that time, whether increase or decline, was mainly derived by technical change except in three years (2005-2007). Positive TFP growth in the provinces of Liaoning and Inner Mongolia, and negative TFP growth in Hebei and Anhui were mainly driven by efficiency change, specifically scale efficiency change except pure technical efficiency in Liaoning.展开更多
利用台风资料、海南灾情资料、再分析资料和多种统计分析方法,确定1967—2015年影响海南岛的15个强台风事件并探析海南岛强台风事件(Hainan violent typhoon event,HNVTE)的影响因子。结果表明,HNVTE发生的气候背景信息表现为多时间尺...利用台风资料、海南灾情资料、再分析资料和多种统计分析方法,确定1967—2015年影响海南岛的15个强台风事件并探析海南岛强台风事件(Hainan violent typhoon event,HNVTE)的影响因子。结果表明,HNVTE发生的气候背景信息表现为多时间尺度因子的协同作用:1980年代后期西北太平洋副热带高压(以下简称“西北太平洋副高”)突变式变强可能为HNVTE的减少提供了年代际尺度背景,厄尔尼诺-南方涛动(El Ni o-Southern Oscillation,ENSO)和平流层准两年振荡(quasi-biennial oscillation,QBO)的共同作用提供了HNVTE变化的年际异常背景。西北太平洋副高突变前出现中等强度的La Ni a状态和突变后出现中等强度的El Ni o状态均有利于HNVTE发生,而平流层西风位相下低层强西风切变则会抑制这两种状态下的HNVTE活动。根据西北太平洋海面温度的年代际位相、ENSO循环位相及强度和QBO位相及强度构建的BEST-QBO协同作用指数能很好地识别HNVTE的发生,可为HNVTE的气候预测提供有用的信号。展开更多
使用对数平均迪氏指数法(Logarithmic Mean Divisia Index,LMDI)从地市层面计算环境、行业和机构等因素或因子对体育彩票销售增长的贡献度,比较各年份或时期相关结果的异同,分析体育彩票销售与经济发展及福利彩票销售的关系。发现:经济...使用对数平均迪氏指数法(Logarithmic Mean Divisia Index,LMDI)从地市层面计算环境、行业和机构等因素或因子对体育彩票销售增长的贡献度,比较各年份或时期相关结果的异同,分析体育彩票销售与经济发展及福利彩票销售的关系。发现:经济发展是影响中国体育彩票销售增长最为稳定和持续的因素,彩票行业并不存在“口红效应”;我国体育彩票较好发挥了统一管理的体制机制优势,在彩票监管部门支持下实现了较高速度的增长;我国体育彩票尚未与福利彩票形成明显的替代关系,但需避免出现此种情况。建议:体育彩票各级机构切实践行正确的销售政绩观,提升体育彩票公信力,扭转公众对彩票的误解,加强体育彩票理论研究,引领行业高质量发展。展开更多
目的:探讨伴有牙周炎超重肥胖人群免疫炎症特点及其与内脏脂肪面积(visceral fat area,VFA)的关系。方法:选择2022年1月~2024年1月我院收治的206例牙周炎患者为研究对象,根据身体质量指数(body mass index,BMI)将患者分为正常组,超重组...目的:探讨伴有牙周炎超重肥胖人群免疫炎症特点及其与内脏脂肪面积(visceral fat area,VFA)的关系。方法:选择2022年1月~2024年1月我院收治的206例牙周炎患者为研究对象,根据身体质量指数(body mass index,BMI)将患者分为正常组,超重组,肥胖组。采用免疫速率散射比浊法、流式细胞仪和酶联免疫吸附法测定免疫炎症因子;采用DBA-550生物电阻抗测量法测量VFA;采用Logistic回归分析免疫炎症因子与VFA之间的关系;使用Logistic回归模型对危险因素交互作用进行分析。结果:三组患者的免疫球蛋白G(immunoglobulin G,IgG)、免疫球蛋白A(IgA)、白介素-4(interleukin-4,IL-4)、IL-17、VFA比较均差异显著(P<0.05)。肥胖组IgG、IgA、IL-4、IL-17、CD4^(+)、CD4^(+)/CD8^(+)、VFA水平高于正常组、超重组(P<0.05),CD8^(+)、IL-10水平低于正常组、超重组(P<0.05)。Logistic回归分析结果显示,VFA增加与IgA、IL-4独立相关(P<0.05),与IgG、IL-17无相关性(P>0.05)。牙周炎组与非牙周炎组的IgG、IgA、IgM、CD4^(+)、CD8^(+)、CD4^(+)/CD8^(+)、IL-4、IL-10、IL-17、VFA水平比较差异显著(P<0.05)。分层回归分析结果显示,IL-4和VFA对患牙周炎产生显著的负向影响关系(P<0.05)。相加交互模型显示,IL-4和VFA在牙周炎发病中存在显著的相加交互作用(P<0.05)。结论:牙周炎患者免疫炎症因子及VFA在不同BMI中有显著差异性,肥胖组牙周炎患者免疫炎症因子水平最高且VFA增加明显,高IL-4水平和超重同时存在时,患牙周炎风险大大增加。展开更多
文摘Soil characterization and heavy metals in different layers (0 - 15 cm;15 - 30 cm and 30 - 45 cm depth) of automobile mechanic waste dumps were studied. The soils showed remarkably high levels of all the metals above background concentrations with most (Ni, Cu, Fe, Cr and Cd) decreasing with soil depth. The distribution pattern were in the following order Fe > Cu > Zn > Pb > Cr > Ni > Cd. Across all the sampling locations and profiles, Fe and Cd showed the highest (476.4 μg·g-1) and least (37.5 μg·g-1) mean concentrations respectively. Pollution load index (PLI) and index of geoaccumulation (Igeo) revealed overall high and moderate contamination respectively but the enrichment factors (EFs) for Pb Ni and Cd are severe. The inter-element relationship revealed the identical source of elements in the soils of the studied area. The accuracy of the results has been cheeked using the standard reference material;SRM (PACS-2). The mechanic waste dumps represent potential sources of heavy metal pollution to environment. The elevated levels of heavy metals in these soil profiles constitute a serious threat to both surface and groundwater.
基金National Natural Science Foundation of China (No.51278182)
文摘When the bridge structure stability safety factor of the first type is 4, the research that whether the structure reliability index will reach target reliability index under the more-likely-to-happen collapse situation of the second type is necessary. The stability calculations of the first and the second type are made respectively for single layer and single span rigid frame bridge. Based on the critical load obtained from the stability calculation of the first type, the stability safety factor of the first type is taken as 4, and the first order reliability method is used to program and calculate the reliability index. Then, the load effect under the stability reliability index cal- culation of the first type and the critical load of the second type are employed to calculate the reliability index of the second type. The evaluation of structure stability safety factor is discussed according to reliability index. Based on the discussion above, parameter analysis of the stable critical loads of two types is made, and the in- fluence of critical load change on reliability index is researched. The result shows that stability analysis should identify collapse state; when the stability safety factor of the first type is 4, but the structure has the collapse of the second type, the reliability index cannot be ensured to reach the target reliability index under certain condi- tions.
文摘This paper presents the global solar radiation (GSR) and cloud transmittance factor (cf) measured at the horizontal surface over a period of one year from 2009 to 2010 using CMP6 Pyranometer and NILUUV Irradiance Meter at Lukla (Latitude 26.69oN,Longitude 86.73?E and Altitude 2850 m) in the foothills of the Mt Everest (8850 m high). Monthly and seasonal variations of global solar radiation as well as correlation between clearness index and cloud transmittance factor at Lukla are presented. The annual average daily global solar radiation is about 3.83 kWh/sq·m/day which is sufficient to promote solar active and passive energy technology at high mountain terrain where there is no other viable alternative sources of energy. The maximum and minimum global solar radiation of 5.33 and 2.08 kWh/sq·m/day is recorded in April and September 2010 respectively. The seasonal variation of solar energy is about 2.87 kWh/sq·m/day and 4.83 kWh/sq·m/day in summer and spring respectively which is not in line with the general trend. The coefficient of determination (R2) between cloud transmittance factor (cf) and clearness factor (K) is found to be 0.97. This novel result can be utilized to estimate the global solar radiation at the horizontal surface where K and cf are available.
文摘BACKGROUND: Ankle brachial index (ABI) is widely involved in researches and clinical application of peripheral vascular injury of patients with diabetes mellitus (DM); however, the application in cerebral infarction (CI) is rare. OBJECTIVE: To investigate the possible risk factor of cerebral infarction plus peripheral arterial disease (PAD), compare metabolic characteristics of patients who having CI plus PAD or only having CI, and understand the significance of ABI on screening and diagnosing CI plus PAD of lower limb. DESIGN: Contrast observation based on CI patients. SETTING: Department of Neurology, Nanxishan Hospital of Guangxi Zhuang Autonomous Region. PARTICIPANTS: A total of 124 CI patients were selected from Department of Neurology, Nanxishan Hospital of Guangxi Zhuang Autonomous Region from July 2005 to April 2006, including 72 males and 52 females aged from 45 to 88 years. All patients met the diagnostic criteria of cerebrovascular disease established by National Academic Conference of Cerebrovascular Diseases in 1995 and determined as cerebral infarction with MRI or CT examination. All patients provided informed consent. There were 46 cases (37.2%) with CI plus PAD and 78 cases (62.8%) only with CI. METHODS: Blood pressure of bilateral ankles and upper extremities was measured at plain clinostatism with DINAMAP blood pressure monitor (GE Company). The ratio between average systolic pressure of lateral ankle and average systolic pressure of both upper extremities was regarded as ABI. The normal ABI was equal to or more than 0.9. If ABI < 0.9 occurred at one side, patients were diagnosed as PAD. On the second morning after hospitalization, blood was collected to measure fasting blood glucose (FBG), 2-hour postprandial blood glucose (PBG2h), glycosylated hemoglobin (HbA1c), triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). Among them, blood glucose, lipid and other biochemical markers were measured with enzyme chemistry assay and HbA1c was measured with HbA1c meter based on high liquid phase. Measurement data and enumeration data were compared with t test and Chi-square test, and multiple factors were dealt with Logistic regression analysis and multivariate linear regression analysis. MAIN OUTCOME MEASURES: Results of correlation between ABI and metabolic markers with multivariate linear regression analysis; risk factors of CI plus PAD with Logistic regression analysis; comparisons of metabolic markers between PAD and non-PAD patients. RESULTS: All 124 patients with acute CI were involved in the final analysis. ① Comparisons of metabolic markers: Levels of serum LDL-C and uric acid (UA) were higher of PAD patients than those of non-PAD patients (t =2.051 9, 3.339 1, P < 0.05); however, there were no significant differences among other metabolic markers (P > 0.05). ② Results of multivariate linear regression analysis: PBG2h, LDL-C and UA were obvious correlation with ABI of posterior tibial artery of lower limb and dorsal pedis artery (partial regression coefficient = -0.231 to -1.010, P < 0.05). ③ Risk factors of CI plus PAD with Logistic regression analysis: Age, smoking history, sum of CI focus (≥3) and LDL-C were independent risk factor of CI plus PAD (OR =1.524-5.422, P < 0.05-0.01). CONCLUSION: ① Levels of serum LDL-C and UA of patients with CI plus PAD are high. ② ABI of lower limbs is correlation with PBG2h, LDL-C and UA. In addition, measuring ABI is beneficial for early diagnosing PAD of lower limbs of patients who have poorly controlled blood glucose, abnormal lipid and poor renal function. ③ Age, LDL-C and sum of CI focus (≥3) are independent risk factors of CI plus PAD. It is of significance for screening non-PAD patients to evaluate risk degrees and prognosis and select therapeutic methods based on ABI measurement.
文摘The low and slowly increasing soybean yield restricts the development of soybean production. Accurate measures of total factor productivity (TFP) for soybean production can be helpful in identifying conditions, institutions or policies that promote soybean production development in China. In this paper, TFP growth for soybean production was estimated for a panel data of 10 major soybean producing provinces from 2005 to 2017. Results reveal that TFP grew at an average rate of 1.3% over the whole period, with technical progress contributing 2.3% and efficiency change providing the other -1.0%. The change of TFP for soybean production over that time, whether increase or decline, was mainly derived by technical change except in three years (2005-2007). Positive TFP growth in the provinces of Liaoning and Inner Mongolia, and negative TFP growth in Hebei and Anhui were mainly driven by efficiency change, specifically scale efficiency change except pure technical efficiency in Liaoning.
文摘利用台风资料、海南灾情资料、再分析资料和多种统计分析方法,确定1967—2015年影响海南岛的15个强台风事件并探析海南岛强台风事件(Hainan violent typhoon event,HNVTE)的影响因子。结果表明,HNVTE发生的气候背景信息表现为多时间尺度因子的协同作用:1980年代后期西北太平洋副热带高压(以下简称“西北太平洋副高”)突变式变强可能为HNVTE的减少提供了年代际尺度背景,厄尔尼诺-南方涛动(El Ni o-Southern Oscillation,ENSO)和平流层准两年振荡(quasi-biennial oscillation,QBO)的共同作用提供了HNVTE变化的年际异常背景。西北太平洋副高突变前出现中等强度的La Ni a状态和突变后出现中等强度的El Ni o状态均有利于HNVTE发生,而平流层西风位相下低层强西风切变则会抑制这两种状态下的HNVTE活动。根据西北太平洋海面温度的年代际位相、ENSO循环位相及强度和QBO位相及强度构建的BEST-QBO协同作用指数能很好地识别HNVTE的发生,可为HNVTE的气候预测提供有用的信号。
文摘使用对数平均迪氏指数法(Logarithmic Mean Divisia Index,LMDI)从地市层面计算环境、行业和机构等因素或因子对体育彩票销售增长的贡献度,比较各年份或时期相关结果的异同,分析体育彩票销售与经济发展及福利彩票销售的关系。发现:经济发展是影响中国体育彩票销售增长最为稳定和持续的因素,彩票行业并不存在“口红效应”;我国体育彩票较好发挥了统一管理的体制机制优势,在彩票监管部门支持下实现了较高速度的增长;我国体育彩票尚未与福利彩票形成明显的替代关系,但需避免出现此种情况。建议:体育彩票各级机构切实践行正确的销售政绩观,提升体育彩票公信力,扭转公众对彩票的误解,加强体育彩票理论研究,引领行业高质量发展。
