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低碳城市试点政策对全要素能源效率的影响机制和异质性研究 被引量:14
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作者 范丹 刘婷婷 《产业经济评论》 CSSCI 2022年第2期93-111,共19页
通过环境政策影响能源效率、推进绿色低碳发展,是助力我国实现“碳达峰”“碳中和”的关键一环。本文基于环境生产技术,采用至强有效前沿最短距离(MinDS)模型测算城市全要素能源效率;利用双重差分法,实证检验低碳试点城市政策对能源效... 通过环境政策影响能源效率、推进绿色低碳发展,是助力我国实现“碳达峰”“碳中和”的关键一环。本文基于环境生产技术,采用至强有效前沿最短距离(MinDS)模型测算城市全要素能源效率;利用双重差分法,实证检验低碳试点城市政策对能源效率的影响,分析影响机制与异质性。研究发现,低碳城市试点政策显著提高了全要素能源效率,经过克服样本自选择、缓解内生性等一系列稳健性检验后,研究结论仍成立。进一步研究发现,试点城市通过优化产业结构和促进技术创新等方式,有效提高了城市能源利用效率;对于要素市场化程度高的城市和资源型城市,该政策对全要素能源效率的提高效果更为显著。本文从更符合能源效率的改进实践角度为全要素能源效率的测算提供新思路;揭示了低碳城市建设对全要素能源效率的影响机制和政策的差异化效应,理论上支撑了政府在推进绿色低碳高质量发展道路上发挥作用。 展开更多
关键词 低碳城市试点政策 全要素能源效率 双重差分
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荷叶碱自组装纳米粒的制备与评价 被引量:1
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作者 但凡 姜维 +3 位作者 徐彩菊 樊洁敏 吴平谷 蒋益虹 《精细化工》 EI CAS CSCD 北大核心 2020年第10期2076-2082,2131,共8页
以大豆卵磷脂和壳聚糖为原料,制备磷脂-壳聚糖自组装纳米粒包埋荷叶碱以提高荷叶碱的稳定性,以包封率为指标探究最佳制备工艺,并对纳米粒的贮藏稳定性、消化稳定性和体外释放特性进行评价。结果表明,当磷脂与壳聚糖质量比为20∶1时,原... 以大豆卵磷脂和壳聚糖为原料,制备磷脂-壳聚糖自组装纳米粒包埋荷叶碱以提高荷叶碱的稳定性,以包封率为指标探究最佳制备工艺,并对纳米粒的贮藏稳定性、消化稳定性和体外释放特性进行评价。结果表明,当磷脂与壳聚糖质量比为20∶1时,原始的溶剂注入法制备的荷叶碱自组装纳米粒包封率只有20.08%;在修改后的溶剂注入法下,在壳聚糖水相中添加质量浓度为20g/L的水溶性维生素E时具有最大包封率(51.13%),此时纳米粒的平均粒径为142.23 nm,电位为+24.57 mV,外形类似球形。自组装纳米粒可显著提升荷叶碱的贮藏稳定性和消化稳定性(P<0.05)。室温下(25℃)经包埋的荷叶碱的半衰期由未被包埋时的36.2 d提升至53.1 d,在低温(4℃)下经包埋的荷叶碱的半衰期由未被包埋时的56.2d提升至86.2d;被纳米粒包埋的荷叶碱经肠消化后的保留率由未被包埋时的20.29%提升至82.98%。体外模拟释放实验表明,自组装纳米粒具有一定的缓释性。 展开更多
关键词 荷叶碱 自组装纳米粒 包封率 稳定性 医药原料
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茶多酚-壳聚糖复合液对鮸鱼在贮藏中品质指标变化的影响 被引量:12
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作者 倪佳丹 潘诗哲 +1 位作者 但凡 蒋益虹 《浙江大学学报(农业与生命科学版)》 CAS CSCD 北大核心 2018年第5期594-600,共7页
以鮸鱼为研究对象,分析茶多酚与壳聚糖复合液对鮸鱼在25℃和4℃贮藏条件下的主要品质指标(生物胺含量、挥发性盐基氮含量、菌落总数)变化的影响。通过正交试验,将茶多酚、壳聚糖配制成复合液,以生物胺含量作为评价指标,筛选出抑制生物... 以鮸鱼为研究对象,分析茶多酚与壳聚糖复合液对鮸鱼在25℃和4℃贮藏条件下的主要品质指标(生物胺含量、挥发性盐基氮含量、菌落总数)变化的影响。通过正交试验,将茶多酚、壳聚糖配制成复合液,以生物胺含量作为评价指标,筛选出抑制生物胺生成的最佳配比液;在用最佳配比液处理后,检测鮸鱼在25℃和4℃贮藏条件下的生物胺含量、挥发性盐基氮含量、菌落总数的变化情况。结果表明:复合液的最佳配比为3 g/L茶多酚与10 g/L壳聚糖,它可使鮸鱼在25℃环境下贮藏24 h和4℃环境下贮藏12 d后的生物胺含量显著降低;并使在25℃和4℃贮藏条件下鮸鱼的生物胺含量、挥发性盐基氮含量、菌落总数均低于未经处理的对照组,货架期可分别延长至30~36 h和12~15 d。 展开更多
关键词 茶多酚 壳聚糖 鮸鱼 品质 贮藏
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响应面法优化荷叶生物碱盐提取工艺及其纯化 被引量:8
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作者 潘诗哲 但凡 +1 位作者 樊洁敏 蒋益虹 《精细化工》 EI CAS CSCD 北大核心 2019年第8期1598-1603,1609,共7页
在单因素实验的基础上,通过响应面法分析和优化提取条件,考察超声酸提法中酸的种类、酸的质量分数、超声时间、液固比〔液体体积(m L)与固体质量(g)的比值〕、超声功率和温度对荷叶碱提取效果的影响以及D101型大孔树脂对提取物的纯化效... 在单因素实验的基础上,通过响应面法分析和优化提取条件,考察超声酸提法中酸的种类、酸的质量分数、超声时间、液固比〔液体体积(m L)与固体质量(g)的比值〕、超声功率和温度对荷叶碱提取效果的影响以及D101型大孔树脂对提取物的纯化效果。得到的荷叶生物碱盐的最佳提取工艺条件为:加热温度60℃、超声功率500 W、盐酸质量分数0.3%、超声时间41 min、液固比27,在该工艺条件下荷叶碱的得率为(4.12±0.05)mg/g。以体积分数为70%的乙醇作为洗脱液,纯化后的生物碱盐经分光光度法测得纯度为40.81%。 展开更多
关键词 荷叶 生物碱盐 提取 纯化 大孔树脂
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Effects of livestock and poultry breeding pollution on health risks:Evidence from a hog breeding case in rural China 被引量:4
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作者 dan fan Yanxin Mao +1 位作者 Lihe Xu Wenguo Wang 《Chinese Journal of Population,Resources and Environment》 2020年第4期342-349,共8页
With the rapid development of livestock and poultry breeding industries,pollution problems caused by the discharge of wastewater and manure have become increasingly severe.However,studies on the impacts of this pollut... With the rapid development of livestock and poultry breeding industries,pollution problems caused by the discharge of wastewater and manure have become increasingly severe.However,studies on the impacts of this pollution on rural residents'health are lacking.Based on data from the Peking University's China Family Panel Studies in 2010 and 2014,this paper uses a cross-sectional and panel data probit model to estimate the probability of breeding industry development in rural areas increasing the health risks of local villagers.First,the study found that the more households engaged in breeding in the region or the larger the scale of regional breeding,the higher the health risks to local villagers,particularly in areas where pigs are raised.Second,compared with individual farming,the greater the proportion of large-scale farming,the higher the health risks to villagers.Third,the development of the breeding industry seldom includes the ecological recycling of wastes and fails to reduce the use of local pesticides and fertilizers,thereby increasing the health risks to villagers.Therefore,this paper argues that providing technology to process breeding industry waste and establish an organic industrial production chain will be crucial to reducing the impact of breeding industry pollution on human health. 展开更多
关键词 FARMING POLLUTION Health risk Rural areas
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A late Carboniferous transition from subduction to collision:Tectonosedimentary evidence from southern Junggar,NW China 被引量:1
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作者 Shuoqin Hou Di Li +4 位作者 Dengfa He Yu Lu Yu Zhen Hao Yang dan fan 《Geoscience Frontiers》 SCIE CAS CSCD 2024年第3期166-179,共14页
The Carboniferous to Permian tectono-sedimentary evolution of the southern Junggar area brings new insights into understanding the subduction-collision processes in the northern Tianshan region.Integrating geophysics,... The Carboniferous to Permian tectono-sedimentary evolution of the southern Junggar area brings new insights into understanding the subduction-collision processes in the northern Tianshan region.Integrating geophysics,geochemistry,and geochronology approaches,this study investigates the Carboniferous-Permian strata in the southern Junggar Basin.The results have revealed three distinct tectono-stratigraphic evolutionary stages,each marked by a distinctive volcano-sedimentary sequence.The Early Carboniferous strata suggest intense volcanic activities in the southern Junggar area.During the Late Carboniferous,the southern Junggar Basin was controlled by normal faulting in an extensional setting,receiving sedimentary inputs from the Junggar terrane.The Lower Permian,unconformably overlying the Upper Carboniferous,was shaped by an extensional regime and is comprised by volcano-clastic sequences that received detritus from the Yili-Central Tianshan block.These findings indicate that a Late Carboniferous forearc basin developed in the southern Junggar area,and it evolved into a post-collisional rift in the Early Permian.This period marked a dynamic shift from bidirectional subduction(rollback)to the detachment of the North Tianshan oceanic slab.We propose that the collision between the YiliCentral Tianshan block and the Junggar terrane,along with the closure of the North Tianshan Ocean,likely occurred in the Late Carboniferous(ca.306-303 Ma). 展开更多
关键词 Tectono-sedimentary evolution Tectonic transition CARBONIFEROUS-PERMIAN Junggar Basin North Tianshan Ocean
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Robust visual tracking based on scale invariance and deep learning 被引量:2
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作者 Nan REN Junping DU +3 位作者 Suguo ZHU Linghui LI dan fan JangMyung LEE 《Frontiers of Computer Science》 SCIE EI CSCD 2017年第2期230-242,共13页
Visual tracking is a popular research area in com- puter vision, which is very difficult to actualize because of challenges such as changes in scale and illumination, rota- tion, fast motion, and occlusion. Consequent... Visual tracking is a popular research area in com- puter vision, which is very difficult to actualize because of challenges such as changes in scale and illumination, rota- tion, fast motion, and occlusion. Consequently, the focus in this research area is to make tracking algorithms adapt to these changes, so as to implement stable and accurate vi- sual tracking. This paper proposes a visual tracking algorithm that integrates the scale invariance of SURF feature with deep learning to enhance the tracking robustness when the size of the object to be tracked changes significantly. Particle filter is used for motion estimation. The co^fidence of each parti- cle is computed via a deep neural network, and the result of particle filter is verified and corrected by mean shift because of its computational efficiency and insensitivity to external interference. Both qualitative and quantitative evaluations on challenging benchmark sequences demonstrate that the pro- posed tracking algorithm performs favorably against several state-of-the-art methods throughout the challenging factors in visual tracking, especially for scale variation. 展开更多
关键词 visual tracking SURF mean shift particle filter neural network
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