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Load-bearing characteristics and energy evolution of fractured rock masses after granite and sandstone grouting
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作者 WU Xu-kun ZHAO Guang-ming +4 位作者 MENG Xiang-rui LIU Chong-yan LIU Zhi-xi HUANG Shun-jie ZHANG Qi-hang 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第8期2810-2825,共16页
Experiments on grouting-reinforced rock mass specimens with different particle sizes and features were carried out in this study to examine the effects of grouting reinforcement on the load-bearing characteristics of ... Experiments on grouting-reinforced rock mass specimens with different particle sizes and features were carried out in this study to examine the effects of grouting reinforcement on the load-bearing characteristics of fractured rock mass.The strength and deformation features of grouting-reinforced rock mass were analyzed under different loading manners;the energy evolution mechanism of grouting-reinforced rock mass specimens with different particle sizes and features was investigated;the energy dissipation ratio and post-peak stress decreasing rate were employed to evaluate the bearing stability of grouting-reinforced rock mass.The results show that the strength and ductility of granite-reinforced rock mass(GRM)under biaxial loading are higher than that of sandstone-reinforced rock mass(SRM)under uniaxial loading.Besides,the energy evolution characteristics of grouting-reinforced rock mass under uniaxial and biaxial loading mainly could be divided into early,middle,and late stages.In the early stage,total,elastic,and dissipation energies were quite small with flatter curves;in the middle stage,elastic energy increased rapidly,whereas dissipation energy increased slowly;in the late stage,dissipation energy increased sharply.The energy dissipation ratio was used to represent the pre-peak plastic deformation.Under uniaxial loading,this ratio increased as the particle size increased and the pre-peak plastic deformation of grouting-reinforced rock mass became larger;under biaxial loading,it dropped as the particle size increased,and the pre-peak plastic deformation of grouting-reinforced rock mass became smaller.The post-peak stress decline rate A_(v) was used to assess the post-peak bearing performance of grouting-reinforced rock mass.Under uniaxial loading,parameter A_(v) exhibited reduction as the particle size kept increasing,and the ability of post-peak of grouting-reinforced rock mass to allow deformation development was greater,and the bearing capacity was greater;under biaxial loading,A_(v) increased with the particle size,and the ability of post-peak of grouting-reinforced rock mass to allow deformation development was low and the bearing capacity was reduced.The findings are considered instrumental in improving the stability of the roadway-surrounding rock by granite and sandstone grouting. 展开更多
关键词 grouting-reinforced rock mass particle size energy dissipation ratio post-peak stress decreasing rate load-bearing characteristics
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Promoting Poverty Alleviation through the Project of Linkage of Urban Construction Land Increase with Rural Construction Land Decrease——A Case Study of Binchuan County in Yunnan Province
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作者 Jing LIU Zisheng YANG 《Asian Agricultural Research》 2018年第3期51-55,65,共6页
The policy of linkage of urban construction land increase with rural construction land decrease is an important task for poverty alleviation. It not only promotes the intensive use of land and the coordinated developm... The policy of linkage of urban construction land increase with rural construction land decrease is an important task for poverty alleviation. It not only promotes the intensive use of land and the coordinated development of urban and rural areas,but also plays an essential role in poverty alleviation development and the relocation of poverty alleviation. It provides a strong guarantee for winning the project of poverty alleviation. Taking the project of linkage of urban construction land increase with rural construction land decrease in Binchuan County in Yunnan Province,combined with the current situation of poverty alleviation and relocation in Binchuan County,the implementation of related policies of linkage of urban construction land increase with rural construction land decrease,and path of relocation poverty alleviation,this paper introduced problems in the implementation of policies of linkage of urban construction land increase with rural construction land decrease in Binchuan County,and came up with recommendations for the project of poverty alleviation through linkage of urban construction land increase with rural construction land decrease. 展开更多
关键词 Linkage of urban construction land increase with rural construction land decrease Tough battle against poverty Relocation of poverty alleviation Recommendations
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A numerical study on characteristics of the maximum storm surges at Tanggu station
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作者 GENG Shanshan SHU Yuting YUE Xinyang 《Marine Science Bulletin》 2022年第1期47-55,共9页
Using the measured data to analyze the change rule of water increase and decrease in the coastal waters of Tanggu station.The water increase caused by the temperate cyclone in winter accounts for a higher frequency in... Using the measured data to analyze the change rule of water increase and decrease in the coastal waters of Tanggu station.The water increase caused by the temperate cyclone in winter accounts for a higher frequency in the whole year,and the water increase caused by the tropical cyclone in summer is larger,which brings serious storm surge disasters.This paper determines the maximum tropical cyclone parameters through statistics of historical typhoon processes,establishes a numerical model of storm water increase and decrease,and calculates the maximum possible water increase caused by typhoons in this sea area,and the water increase value is 3.6 m.A gale sensitivity experiment was constructed,and the maximum possible increase or decrease of water in the gale was calculated. 展开更多
关键词 Tanggu Station maximum possible increase or decrease of water storm surge
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Dielectric properties and temperature increase characteristics of zinc oxide dust from fuming furnace 被引量:1
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作者 张利波 马爱元 +4 位作者 刘晨辉 曲雯雯 彭金辉 罗永光 左勇刚 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第12期4004-4011,共8页
Cavity perturbation method was used to determine the dielectric properties (ε′,ε″, and tanδ) of zinc oxide dust in different apparent densities. The process was conducted to study the microwave-absorption prope... Cavity perturbation method was used to determine the dielectric properties (ε′,ε″, and tanδ) of zinc oxide dust in different apparent densities. The process was conducted to study the microwave-absorption properties of zinc oxide dust and the feasibility of microwave roasting zinc oxide dust to remove fluorine and chlorine. The dielectric constant, dielectric loss, and loss tangent were proportional to the apparent density of zinc oxide dust. The effects of sample mass and microwave power on the temperature increase characteristics under the microwave field were also studied. The results show that the apparent heating rate of the zinc oxide dust increases with the increase in microwave roasting power and decreases with the increase in the sample mass. The temperature of the samples reaches approximately 800 &#176;C after microwave treatment for 8 min, which indicates that the zinc oxide dust has strong microwave-absorption ability. 展开更多
关键词 zinc oxide dust apparent density dielectric properties microwave heating temperature increase characteristics
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New Computation of Unified Bounds via a More General Fractional Operator Using Generalized Mittag-Leffler Function in the Kernel
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作者 Saima Rashid Zakia Hammouch +1 位作者 Rehana Ashraf Yu-Ming Chu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2021年第1期359-378,共20页
In the present case,we propose the novel generalized fractional integral operator describing Mittag-Leffler function in their kernel with respect to another function Φ.The proposed technique is to use graceful amalga... In the present case,we propose the novel generalized fractional integral operator describing Mittag-Leffler function in their kernel with respect to another function Φ.The proposed technique is to use graceful amalgamations of the Riemann-Liouville(RL)fractional integral operator and several other fractional operators.Meanwhile,several generalizations are considered in order to demonstrate the novel variants involving a family of positive functions n(n∈N)for the proposed fractional operator.In order to confirm and demonstrate the proficiency of the characterized strategy,we analyze existing fractional integral operators in terms of classical fractional order.Meanwhile,some special cases are apprehended and the new outcomes are also illustrated.The obtained consequences illuminate that future research is easy to implement,profoundly efficient,viable,and exceptionally precise in its investigation of the behavior of non-linear differential equations of fractional order that emerge in the associated areas of science and engineering. 展开更多
关键词 Integral inequality generalized fractional integral with respect to another function increasing and decreasing functions Mittag-Leffler function
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Discussion on Mode of Key Link in Increase and Decrease Connection of Urban and Rural Construction Land
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作者 Ai DENG Min JIANG +5 位作者 Qinfang LI Xiaoting XU Xiaoxia ZHANG Hui JING Na ZHANG Chao HU 《Asian Agricultural Research》 2013年第5期79-82,共4页
With the methods of qualitative analysis, induction and deduction, modes of key links in increase and decrease connection of urban and rural construction land are proposed in view of the involved three key links, name... With the methods of qualitative analysis, induction and deduction, modes of key links in increase and decrease connection of urban and rural construction land are proposed in view of the involved three key links, namely reclamation of rural construction land, fund raising and management of connection turnover index, based on the comprehensive analysis of political connotation in increase and decrease of urban and rural construction land. The modes include "village relocation and combination", "hollow village" reconstruction, high-rise stereo, village relocation in the mountain and related capital raising and turnover index management and the applicable regions of various modes are analyzed and studied. The research result provides reference for the reasonable operation of increase and decrease link of urban and rural construction land. 展开更多
关键词 URBAN and RURAL construction LAND increase and DEC
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Construction controlling and strength increasing characteristics of locally developed epoxy asphalt mixture 被引量:7
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作者 陈春 钱振东 陈磊磊 《Journal of Southeast University(English Edition)》 EI CAS 2011年第1期61-64,共4页
The construction controlling elements,including construction performance at low ambient temperatures,reserved time ranges,and the strength increasing rule,for locally developed epoxy asphalt mixture(LDEAM) are studi... The construction controlling elements,including construction performance at low ambient temperatures,reserved time ranges,and the strength increasing rule,for locally developed epoxy asphalt mixture(LDEAM) are studied through laboratory tests.Air void and Marshall stability are chosen as the performance measures for evaluating the construction quality.The wheel rolling test is used to simulate the actual construction situations,while the Marshall test and the Brookfield viscosity test are adopted to study the strength increasing rule.The experimental results reveal that the LDEAM can be constructed under a low ambient temperature condition of 10℃,and its longest reserved time is 70 min at a reserved temperature of 120℃.Test also shows that the strength of the LDEAM increases with time and temperature before cured.Finally,the theoretical reason for the strength increasing rule is analyzed on the basis of the organic chemistry theory. 展开更多
关键词 construction characteristics locally developed epoxy asphalt strength increasing characteristics
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Long Term Temperature Trends at Major, Medium, Small Cities and Hill Stations in India during the Period 1901-2013 被引量:2
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作者 Dilip Rajaram Kothawale Nayana Rajendra Deshpande Rupa Kumar Kolli 《American Journal of Climate Change》 2016年第3期383-398,共16页
Industrialization and urbanization are the most dominant causal factors for long-term changes in surface air temperatures. To examine this fact, the long term changes in the surface-air temperatures have been evaluate... Industrialization and urbanization are the most dominant causal factors for long-term changes in surface air temperatures. To examine this fact, the long term changes in the surface-air temperatures have been evaluated by the linear trend for the different periods, i.e. 1901-2013, 1901-1970 and recent period 1971-2013 as rapid industrialization was observed during the recent four decades. In the present study, seasonal and annual mean, maximum and minimum temperature data of 36 stations for the period 1901-2013 have been used. These stations are classified into 4 groups, namely major, medium, small cities and hill stations. During the period 1901-1970, less than 50% stations from each group showed a significant increasing trend in annual mean temperature, whereas in the recent period 1971-2013, more than 80% stations from all the groups except small city group showed a significant increasing trend. The minimum temperature increased faster than that of the maximum temperature over major and medium cities, while maximum temperature increased faster than the minimum temperature over the small cities and hill stations. The annual mean temperature of all the coastal stations showed a significant increasing trend and positive correlation with Precipitable Water Vapour (PWV). The effect of PWV is more pronounced on minimum temperature than that of the maximum. 展开更多
关键词 Increasing Trend Decreasing Trend Temperature Anomalies Aerosol Index Precipitable Water Vapour
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The study of The monotoni city of a class of Exponen tial seque ces
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作者 Zeng Cho Hua 《广东第二师范学院学报》 1994年第3期9-15,共7页
ThestudyofThemonotonicityofaclassofExponentialsequencesZengChoHuaAbstractInThepaper,Wediscussaproblemofthemo... ThestudyofThemonotonicityofaclassofExponentialsequencesZengChoHuaAbstractInThepaper,Wediscussaproblemofthemonotonicityofseque... 展开更多
关键词 Sequence Convergence MONOTONE increase decrease L’H-ospital’s rule.
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Difference of Regional Benefits after Linking Newly-added Cropland Quotas with Amount of Land Used for Construction Based on Targeted Poverty Alleviation: A Case Study of Xinjiang
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作者 Xionghua YUAN Weiliang TU 《Asian Agricultural Research》 2019年第8期15-19,共5页
In order to explore the differences of projects on linking newly-added cropland quotas with the amount of land used for construction in targeted poverty alleviation in different rural areas,this paper selects the soci... In order to explore the differences of projects on linking newly-added cropland quotas with the amount of land used for construction in targeted poverty alleviation in different rural areas,this paper selects the social,economic,cultural and ecological evaluation indexes,and introduces the AHP method,to measure the benefits before and after the implementation of the four typical projects on linking newly-added cropland quotas with the amount of land used for construction in Xinjiang. The results show that after the implementation of the project,the social,economic,cultural,ecological and comprehensive benefits of each region have been improved,but the benefits of regions with different economic levels are significantly different. This paper holds that the projects on linking newly-added cropland quotas with the amount of land used for construction in different regions should be considered from the ultimate goal before the establishment and implementation of the project,so as to realize the win-win situation between the urban-rural requisition-compensation balance and the targeted poverty alleviation in rural areas. 展开更多
关键词 increase-decrease LINKAGE projects TARGETED POVERTY alleviation Regional BENEFITS
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Research on the Policy of "Man-Land-Money" Linkage in the Process of Urbanization
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作者 Huilin ZENG 《Asian Agricultural Research》 2020年第1期19-21,共3页
At present,there are many problems in the self-circular development model of"land transfer-real estate development-land financeurban sprawl"in China.The endogenous power of policy implementation is insuffici... At present,there are many problems in the self-circular development model of"land transfer-real estate development-land financeurban sprawl"in China.The endogenous power of policy implementation is insufficient,the top-level design is not systematic enough,the departmental linkage mechanism is flawed,the local basic data is weak,and there are difficulties in technical operation.According to the current situation,this paper puts forward the following policy suggestions:based on the establishment of financial transfer payment mechanism in rural areas,the construction of the system of man,land and money should be promoted in coordination,and a scientific monitoring system of urbanization degree should be established,so as to make up for the deficiency of the slow speed of"man urbanization"and make the new urbanization healthy and sustainable. 展开更多
关键词 Man-land-money URBANIZATION Agricultural population increase-decrease LINKAGE
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灯泡贯流式水轮机增减负荷动态特性分析
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作者 赵亚萍 赵晨 +2 位作者 秦笛舸 郑小波 郭鹏程 《农业工程学报》 EI CAS CSCD 北大核心 2024年第5期99-108,F0003,共11页
水轮机频繁经历变负荷工况转换过程,使得机组在较短时间内工作参数急剧变化,严重影响电站稳定运行。该研究以某贯流式水轮机为研究对象,在考虑自由液面和水体重力的情况下,采用动网格技术对贯流式水轮机相同出力范围下的减、增负荷过渡... 水轮机频繁经历变负荷工况转换过程,使得机组在较短时间内工作参数急剧变化,严重影响电站稳定运行。该研究以某贯流式水轮机为研究对象,在考虑自由液面和水体重力的情况下,采用动网格技术对贯流式水轮机相同出力范围下的减、增负荷过渡过程的动态特性进行分析。研究结果表明:由于增负荷和减负荷过渡过程的起始工况导致起始流动状态不同,因此在相同出力时,机组内的流动分布不同,减负荷过程尾水管内的涡流面积及强度明显小于增负荷工况,且尾水管涡带尺度也明显小于增负荷过程;相比于增负荷过程,减负荷过程中转轮叶片大范围的低压区极易引发空化;机组内的水压力脉动主要以尾水管涡带引起的0.1f_n(f_n为转频)低频压力脉动和转轮的旋转引起3f_n的高频压力脉动为主,增负荷过程的压力脉动幅值明显大于减负荷过程,两种压力脉动共同作用,使得贯流式水轮机主要振动区域集中于转轮。研究结果对贯流式水轮机的设计与运行具有一定的指导意义。 展开更多
关键词 数值模拟 振动 压力脉动 增减负荷过渡过程 涡带 水轮机
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YORK氨压机单板机系统改造
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作者 陈浩林 《中国仪器仪表》 2023年第8期66-68,共3页
酮苯脱蜡装置进口氨压机控制系统为约克公司RWBII PLUS单板机,此套系统已连续投用20余年。通过本次技术改造,选用西门子公司S7-300 PLC控制系统,实现了机组的平稳控制,同时对该系统的运行画面、电源系统进行优化,为该系统及装置的安全... 酮苯脱蜡装置进口氨压机控制系统为约克公司RWBII PLUS单板机,此套系统已连续投用20余年。通过本次技术改造,选用西门子公司S7-300 PLC控制系统,实现了机组的平稳控制,同时对该系统的运行画面、电源系统进行优化,为该系统及装置的安全平稳运行奠定基础。 展开更多
关键词 控制系统 PLC 增减载
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基于融合特征ADRMFCC的语音识别方法
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作者 朵琳 马建 +1 位作者 韦贵香 唐剑 《吉林大学学报(理学版)》 CAS 北大核心 2024年第4期943-950,共8页
针对在复杂噪声环境下语音识别准确率低和鲁棒性差的问题,提出一种基于增减残差Mel倒谱融合特征的语音识别方法.该方法首先利用增减分量法筛选关键语音特征,然后将其映射到Mel域-残差域空间坐标系中生成增减残差Mel倒谱系数,最后将这些... 针对在复杂噪声环境下语音识别准确率低和鲁棒性差的问题,提出一种基于增减残差Mel倒谱融合特征的语音识别方法.该方法首先利用增减分量法筛选关键语音特征,然后将其映射到Mel域-残差域空间坐标系中生成增减残差Mel倒谱系数,最后将这些融合特征用于训练端到端模型.实验结果表明,该方法在不同噪声类型和信噪比条件下均显著提高了语音识别准确率及性能,在-5 dB低信噪比条件下,语音识别准确率达73.13%,而在其他噪声条件下的平均语音识别准确率达88.67%,充分证明了该方法的有效性和鲁棒性. 展开更多
关键词 语音识别 残差Mel倒谱系数 特征筛选 增减分量法
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2023剧集:在产业发展新格局中坚守品质与创新
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作者 戴清 《中国文艺评论》 2024年第2期17-31,I0001,共16页
2023年度,剧集生产继续减量提质,网络剧创制能力已超越电视剧。在剧集生产发行与播出中,总台与各大视频平台合作联动紧密,锚定市场热点与剧集影响力;网台间观众的题材偏好分歧明显,年轻观众对市场热点与剧集口碑的影响愈加强大,各视频... 2023年度,剧集生产继续减量提质,网络剧创制能力已超越电视剧。在剧集生产发行与播出中,总台与各大视频平台合作联动紧密,锚定市场热点与剧集影响力;网台间观众的题材偏好分歧明显,年轻观众对市场热点与剧集口碑的影响愈加强大,各视频平台、不同地区的优秀剧集的创制产能有优异表现,也有拉大差距之势。2023年各题材剧集创作多样创新、繁花锦簇,重大革命历史题材与重大现实题材等主题性剧集领航创作风向,坚持以人民为中心的创作导向;其他题材创作如科幻剧、悬疑涉案剧、都市情感剧、历史传奇及各类古装剧中的优秀作品呈现出蕴涵丰厚、地缘美学特色及其个性化风格追求。 展开更多
关键词 2023剧集 减量提质 审美偏好 地缘美学 个性化风格
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调水调沙期黄河下游河道洪峰增值预测方法研究
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作者 赵连军 韩沙沙 董其华 《人民黄河》 CAS 北大核心 2024年第9期37-41,共5页
准确预测黄河调水调沙期出现的洪峰增值现象,不仅是水库工程调度和下游防洪工程防护的迫切需要,同时也是水力学及河流动力学学科研究面临的新课题。以增值比例为因变量,以小浪底沙峰、含沙量涨峰期平均涨率、含沙量起涨前基流、悬沙粒... 准确预测黄河调水调沙期出现的洪峰增值现象,不仅是水库工程调度和下游防洪工程防护的迫切需要,同时也是水力学及河流动力学学科研究面临的新课题。以增值比例为因变量,以小浪底沙峰、含沙量涨峰期平均涨率、含沙量起涨前基流、悬沙粒径等小浪底出库水沙特征参数为自变量,基于相关性分析筛选出沙峰、含沙量涨峰期平均涨率作为洪峰增值的预判参数。研究发现,当小浪底含沙量涨峰期平均涨率超过22.9 kg/(m^(3)·h)时,小浪底至花园口河段可能发生洪峰增值现象,并可基于小浪底沙峰与增值比例之间的相关关系预测增值区间;对2023年调水调沙期小浪底水文站实时水情、沙情进行跟踪,在小浪底水文站第一个沙峰出现后,对小浪底至花园口河段洪峰增值进行了预测预报,预测结果与实测结果基本一致。 展开更多
关键词 洪峰增值 特征参数 预测方法 调水调沙 黄河下游
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食用植物油中苯并(a)芘的污染特征及城乡居民膳食暴露评估——以汉中市为例 被引量:1
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作者 杨靓 牟霄 张崇淼 《中国油脂》 CAS CSCD 北大核心 2024年第6期106-111,共6页
为了探究食用植物油苯并(a)芘暴露给城乡居民带来的健康风险,通过对陕西省汉中市市售食用植物油进行抽样,利用HPLC-荧光检测法检测苯并(a)芘含量,结合对各区县居民的问卷调查,研究食用植物油中的苯并(a)芘污染特征,计算经食用植物油途... 为了探究食用植物油苯并(a)芘暴露给城乡居民带来的健康风险,通过对陕西省汉中市市售食用植物油进行抽样,利用HPLC-荧光检测法检测苯并(a)芘含量,结合对各区县居民的问卷调查,研究食用植物油中的苯并(a)芘污染特征,计算经食用植物油途径的苯并(a)芘暴露限值,并定量评价食用植物油苯并(a)芘暴露给不同类型人群造成的增加寿命期癌风险(ILCR)。结果表明:市售食用植物油样品中苯并(a)芘的检出率为62.5%,苯并(a)芘含量均值为1.0μg/kg,菜籽油和其他植物油中的苯并(a)芘含量不存在显著差异(p>0.05),食用植物油中苯并(a)芘含量与酸值存在显著相关性(p<0.05),与过氧化值之间不存在显著相关性(p>0.05);汉中市居民食用植物油平均摄入量为35.17g/d,96.2%的居民主要食用植物油为菜籽油;汉中市男性和女性居民经食用植物油途径的苯并(a)芘慢性摄入量分别为0.52ng/(kg·d)和0.59ng/(kg·d),汉中市各区县居民的食用植物油苯并(a)芘暴露限值均大于10000,表明汉中市各区县居民经食用植物油摄入苯并(a)芘的健康风险较低;食用植物油苯并(a)芘暴露导致男性和女性居民的ILCR分别在8.95×10^(-7)~1.53×10^(-5)和1.01×10^(-6)~1.74×10^(-5)范围内,99.6%汉中市男性居民和100%女性居民ILCR稍高于可接受风险水平(1.0×10^(-6)),汉中市其他区县居民食用植物油苯并(a)芘暴露产生的ILCR显著高于汉台区居民的(p<0.05)。综上,汉中市各区县居民经食用植物油摄入苯并(a)芘的健康风险较低,但存在一定的致癌风险,适当减少食用植物油的摄入量有助于降低风险。 展开更多
关键词 苯并(A)芘 食用植物油 污染特征 暴露限值 增加寿命期癌风险
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基于分子动力学的升温条件下煤中锂吸附扩散特性研究
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作者 张俊爽 张彬 +1 位作者 孙蓓蕾 刘超 《地质学报》 EI CAS CSCD 北大核心 2024年第8期2499-2508,共10页
煤是特殊的沉积有机岩石,在其形成过程中可以富集战略性金属,并在煤系中形成大型或超大型金属矿床,成为矿产资源勘探的重要领域。温度是影响煤化作用及其过程中锂等关键金属赋存方式变化的重要因素。为了研究升温过程对煤中锂吸附特征... 煤是特殊的沉积有机岩石,在其形成过程中可以富集战略性金属,并在煤系中形成大型或超大型金属矿床,成为矿产资源勘探的重要领域。温度是影响煤化作用及其过程中锂等关键金属赋存方式变化的重要因素。为了研究升温过程对煤中锂吸附特征的影响,本文以内蒙古准格尔煤田典型高锂煤为研究对象,构建锂-煤可视化模型,通过分子动力学方法计算了不同温度点锂在煤结构中的径向分布函数、扩散系数,分析了锂与有机大分子结构和高岭石相互作用能的变化,探讨了煤结构对锂的吸附特征。结果表明:锂在吸附过程中与氮原子、有机结构中的氧原子和硅原子存在较强的相互作用,与其他原子相互作用较弱或者不存在相互作用。锂与氮原子和有机结构中的氧原子主要是通过氢键作用吸附,而与硅原子则存在静电力和范德华力作用。从20℃升温到300℃的过程中,锂扩散系数受到温度和煤结构变化的影响,呈现出先升高后降低的趋势;煤结构对锂的吸附作用能以静电能为主。 展开更多
关键词 准格尔煤田 分子动力学 升温 吸附特征
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土地要素空间配置对县域经济增长的影响:基于县域内城乡建设用地增减挂钩的政策分析
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作者 吴雨恒 覃莉 +2 位作者 姚树荣 路乾 杨帆 《中央财经大学学报》 北大核心 2024年第9期3-19,共17页
党的二十届三中全会《决定》提出“完善城乡融合发展体制机制”。县域作为城乡融合发展的基本单元,其土地要素空间配置对县域经济发展具有重要作用。城乡建设用地增减挂钩政策是国家促进城乡土地要素空间流动和优化配置的举措之一,但其... 党的二十届三中全会《决定》提出“完善城乡融合发展体制机制”。县域作为城乡融合发展的基本单元,其土地要素空间配置对县域经济发展具有重要作用。城乡建设用地增减挂钩政策是国家促进城乡土地要素空间流动和优化配置的举措之一,但其对社会经济发展的价值和贡献往往被忽视,且存在争议。本文使用全国2006—2022年县域内增减挂钩项目数据,采用双向固定效应模型评估了县域内实施城乡建设用地增减挂钩对经济增长的影响。研究结果表明,县域内增减挂钩政策的实施显著提高了地区生产总值水平,在推动县域经济增长方面具有正向政策效应。县域内增减挂钩通过优化城乡土地资源配置和充实地方政府财政收入,推动了县域经济发展。在东部沿海地区和邻近中心城市的地区、财政自给率较高的地区以及市场化水平较高的地区,增减挂钩对县域经济增长的促进作用更大。研究结论对进一步完善和改进城乡建设用地增减挂钩政策,建设统一的土地资源要素市场提供了有益参考。 展开更多
关键词 增减挂钩政策 县域经济 空间配置 要素市场
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云南特色花生绿色高效生产技术集成应用
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作者 张立帆 陆建美 +4 位作者 张玉松 舒兴香 陈晓艳 刘珏 原小燕 《中国油料作物学报》 CAS CSCD 北大核心 2024年第3期536-543,共8页
据国家统计局数据显示,云南花生单产低,约为全国花生单产(3.92 t/hm^(2))的50%,严重阻碍了云南花生生产和产业发展。为提高云南的花生单产,增加效益,本文集成了“因地制宜机械化生产”、“种子包衣”、“增密播种”、“专用缓(控)释肥... 据国家统计局数据显示,云南花生单产低,约为全国花生单产(3.92 t/hm^(2))的50%,严重阻碍了云南花生生产和产业发展。为提高云南的花生单产,增加效益,本文集成了“因地制宜机械化生产”、“种子包衣”、“增密播种”、“专用缓(控)释肥高效施肥”、“主要病虫害绿色高效防控”等关键核心技术,初步建立了云南特色花生绿色高效生产技术体系。该体系的应用成效显著,2022-2023年建成了技术集成核心示范区3377 hm^(2),示范区花生平均单产达到5.37 t/hm^(2),是目前云南平均单产的2.73倍,平均产值达到120791元/hm^(2),同时减少约30%的化肥施用量,减少约55人/hm^(2)的劳动力投入,达到了节本、提质和增效的目的,为云南花生单产提升贡献了重要的科技力量。本文还提出了未来云南特色花生生产的发展方向,以期为花生生产提单产和增效益提供参考。 展开更多
关键词 云南 特色花生 绿色高效生产 产量提升
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