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Effect of Two Substrate Types on Feeding Efficiency by Juvenile Chinese Sturgeon Acipenser sinensis on Barcheek Goby Rhinogobius giurinus
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作者 Xiaolian Gu Jianyi Liu +5 位作者 sikai wang Tao Zhang Feng Zhao Ping Zhuang Ming Duang Boyd Kynard 《Agricultural Sciences》 2023年第10期1436-1443,共8页
We conducted experiments in an artificial stream tank with wild juvenile Chinese sturgeon Acipenser sinensis captured in the Yangtze Estuary to test the null hypothesis that their feeding efficiency on Barcheek goby R... We conducted experiments in an artificial stream tank with wild juvenile Chinese sturgeon Acipenser sinensis captured in the Yangtze Estuary to test the null hypothesis that their feeding efficiency on Barcheek goby Rhinogobius giurinus was not affected by sand vs. smooth glass substrate. Gobies are among the most common prey eaten by wild juvenile A. sinensis in the estuary. Test results found neither substrate type significantly affected feeding efficiency by juveniles. Previous research found a strong innate habitat preference of A. sinensis for sand substrate. The present results indicate that the preference for sand is not related to efficiently capturing R. giurinus on sand, but is an adaptation predisposing juvenile A. sinensis to seek sandy substrate where R. giurinus and other benthic forage are the most abundant in the Yangtze Estuary. 展开更多
关键词 Acipenser sinensis Feeding Efficiency Sand Substrate BEHAVIOR
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单原子催化:追寻催化领域的“圣杯”
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作者 王思恺 闵祥婷 +2 位作者 乔波涛 颜宁 张涛 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2023年第9期1-13,共13页
在催化领域,“圣杯”反应是指对人类未来具有显著的科学、经济和环境可持续性价值的反应.这些反应利用地球上丰富易得的资源,如CH_(4),H_(2)O,CO_(2)和N_(2)等,生产各种有价值的化工产品.尽管意义重大,但由于反应物的化学惰性和产物相... 在催化领域,“圣杯”反应是指对人类未来具有显著的科学、经济和环境可持续性价值的反应.这些反应利用地球上丰富易得的资源,如CH_(4),H_(2)O,CO_(2)和N_(2)等,生产各种有价值的化工产品.尽管意义重大,但由于反应物的化学惰性和产物相对活泼的特点,反应的转化率通常较低,对目标产物的选择性较差.目前,降低“圣杯”反应的活化能垒仍然是一个巨大的挑战,需要开发新型催化剂来应对以上挑战.单原子催化剂(SAC)含有部分带电的金属单原子物种,具有明确的、可调的结构,是一类很有前途的负载型催化剂,不仅可以提升催化性能,也为深入了解反应机制和构效关系提供便利.本文总结和评价了SAC在五个“圣杯”反应中的最新应用.围绕甲烷活化,介绍了甲烷温和氧化制甲醇和无氧甲烷偶联两类反应.热催化甲烷氧化通常需要引入共还原剂来提升催化活性,因此所采用的SAC通过多位点协同作用,实现串联催化过程以有效活化甲烷;而光催化过程则可在无共还原剂的情况下,通过不同单原子金属位点(如Au,Pd,Fe,W)与水或O_(2)的作用,产生活性氧物种,实现甲烷活化.目前用于甲烷氧化的SAC仍缺乏统一的设计和优化标准,在效率提升和机理研究等方面有很大发展空间.对于无氧甲烷偶联反应,目前开发的SAC主要有Fe,Pt和Pd基催化剂,其中单原子位点有助于抑制积碳,提升性能稳定性和产物选择性.然而,部分SAC在高温无氧气氛下难以维持其单原子结构,仍需进一步探索和优化.随后介绍了两种人工光合成反应,即水分解产氢和CO_(2)还原.对于光催化产氢,SAC独特且结构明确的位点可显著提升产氢乃至全解水的性能,也可用于产氢机理的深入研究.对于光催化CO_(2)还原,重点介绍了对生成CO,CH_(4)和CH_3OH具有高选择性的SAC,其中,单原子位点对于调节小分子中间体的吸附起到了重要作用,从而影响了选择性.许多用于人工光合成的SAC存在不止一种催化位点,这些位点可以协同提升目标反应的效率.最后,展示了SAC用于氮气活化合成氨的研究进展,大多采用非贵金属位点(如Fe,Co和La),通过特定的配位结构实现与N_(2)的特殊作用,以有效削弱N≡N键强度.本文最后总结了SAC在“圣杯”反应中的优势和面临的诸多挑战,并提出了该领域未来可能的发展方向,其中包括深入探究机理和构效关系,结合先进信息技术高效筛选符合条件的催化剂,以及设计新型催化位点以扩大催化材料的应用领域. 展开更多
关键词 单原子催化剂 人工光合成 选择性甲烷氧化 无氧甲烷偶联 光催化制氢 二氧化碳光还原 氮气活化
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轻掺杂硅基神经电极的光噪声消减 被引量:1
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作者 魏春蓉 王飞 +10 位作者 裴为华 刘智多 毛旭瑞 赵宏泽 王思凯 王毅军 杨晓伟 刘媛媛 赵姗姗 归强 陈弘达 《物理化学学报》 SCIE CAS CSCD 北大核心 2020年第12期109-115,共7页
硅基神经电极是记录神经细胞放电活动的一种实用工具。使用标准的集成电路加工技术,在宽度仅为70μm的单个硅基针上能排布上千个电极记录位点。光遗传学的发展使控制神经元活动更加精确,通过在给予光刺激的同时记录神经元的电活动,可以... 硅基神经电极是记录神经细胞放电活动的一种实用工具。使用标准的集成电路加工技术,在宽度仅为70μm的单个硅基针上能排布上千个电极记录位点。光遗传学的发展使控制神经元活动更加精确,通过在给予光刺激的同时记录神经元的电活动,可以获取更丰富的脑活动信息。当使用黄光或蓝光刺激神经元时,光子的能量大于硅衬底的禁带宽度,价带电子被激发到导带,从而生成电子-空穴对。因此,在光刺激下使用硅基神经电极时,硅基板中的光生载流子将严重干扰电极的信噪比。为满足在光刺激同时记录电活动的应用需求,必须减少光对硅基神经电极的噪声干扰。传统的降噪方法是使用重掺杂硅作为衬底材料,通过增加杂质浓度来降低载流子寿命,从而降低硅电极的光学噪声。但是,重掺杂的硅衬底比轻掺杂的硅衬底具有更多的晶格缺陷,这使得硅基电极更加脆弱,并且该方法与标准的集成电路加工技术不兼容。通过分析在轻掺杂硅衬底上制造电极的光致噪声机理,我们发现由光激发产生的载流子的不均匀分布将使轻掺杂硅衬底极化。由光致极化引起的电势将影响在其上制造的电极。将轻掺杂硅衬底金属化和接地将有效降低极化电位。使用这种方法,由光诱发的噪声幅度将下降到原始值的0.87%。为了确保神经元的放电率,将光刺激脉冲频率选择为20 Hz。在1 mW·mm^(-2)的光照下,电极的背景噪声可控制在45μV以下,可以满足一般光遗传学应用的需求。经过上述方式改造后的轻掺杂硅衬底将满足光遗传学应用对神经探针的要求。与传统的通过重掺杂整个衬底降低光噪声方法不同,该方法与标准的集成电路加工技术兼容,为利用标准集成电路加工技术制备高密度、高通量硅电极提供了噪声消除方法。 展开更多
关键词 光噪声 光生载流子 光遗传学 轻掺杂 硅基神经微探针
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Estimating the macrobenthic species richness with an optimized sampling design in the intertidal zone of Changjiang Estuary 被引量:3
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作者 Tingting Zhang Feng Zhao +4 位作者 sikai wang Tao Zhang Jianyi Liu Yu Gao Ping Zhuang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2019年第2期114-124,共11页
It is a challenge in the field sampling to face conflict between the statistical requirements and the logistical constraints when explicitly estimating the macrobenthos species richness in the heterogeneous intertidal... It is a challenge in the field sampling to face conflict between the statistical requirements and the logistical constraints when explicitly estimating the macrobenthos species richness in the heterogeneous intertidal wetlands. To solve this problem, this study tried to design an optimal, efficient and practical sampling strategy by comprehensively focusing on the three main parts of the entire process(to optimize the sampling method, to determine the minimum sampling effort and to explore the proper sampling interval) in a typical intertidal wetland of the Changjiang(Yangtze) Estuary, China. Transect sampling was selected and optimized by stratification based on pronounced habitat types(tidal flat, tidal creek, salt marsh vegetation). This type of sampling is also termed within-transect stratification sampling. The optimal sampling intervals and the minimum sample effort were determined by two beneficial numerical methods: Monte Carlo simulations and accumulative species curves. The results show that the within-transect stratification sampling with typical habitat types was effective for encompassing 81% of the species, suggesting that this type of sampling design can largely reduce the sampling effort and labor. The optimal sampling intervals and minimum sampling efforts for three habitats were determined: sampling effort must exceed 1.8 m^2 by 10 m intervals in the salt marsh vegetation, 2 m^2 by 10 m intervals in the tidal flat, and 3 m^2 by 1 m intervals in the tidal creek habitat. It was suggested that the differences were influenced by the mobility range of the dominant species and the habitats' physical differences(e.g., tidal water, substrate, vegetation cover). The optimized sampling strategy could provide good precision in the richness estimation of macrobenthos and balance the sampling effort. Moreover, the conclusions presented here provide a reference for recommendations to consider before macrobenthic surveys take place in estuarine wetlands. The sampling strategy, focusing on the three key parts of the sampling design, had a good operational effect and could be used as a guide for field sampling for habitat management or ecosystem assessment. 展开更多
关键词 SPECIES richness estimation sample strategy TRANSECT sampling optimization Monte Carlo simulation SPECIES ACCUMULATIVE curves Changjiang(Yangtze)Estuary
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Estimation of estuarine habitat degradation and its influence on the reproduction process of the crab Eriocheir sinensis in the Yangtze River Estuary
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作者 Tingting Zhang Nan Du +7 位作者 Zhi Geng sikai wang Yu Gao Gang Yang Xiaorong Huang Tao Zhang Ping Zhuang Feng Zhao 《Ecological Processes》 SCIE EI CSCD 2023年第1期828-842,共15页
Background The provision of habitat for fishery species in estuaries is highly valued and represents one of the most challenging ecosystem service values to quantify.However,quantifying this value is challenging due t... Background The provision of habitat for fishery species in estuaries is highly valued and represents one of the most challenging ecosystem service values to quantify.However,quantifying this value is challenging due to complex relationships between habitat change,ecological processes,and environmental variations.This study aims to estimate estuarine habitat degradation and its impact on the reproduction process of the crab Eriocheir sinensis by characterizing the changes in breeding habitat and investigating relationships between the species and its habitat in the Yang-tze River Estuary.Methods A species distribution model recently developed was applied to estimate the extent and quality of breeding habitat changes from 2014-2021.The intrinsic(physiological)and external(structural)reproductive attributes of the breeding process were measured to assess the effects of habitat change.The relationships among habitat change,reproductive attributes and environmental factors were analyzed to understand the underlying driving forces of habitat degradation for breeding process by multivariate statistical analysis.Results About 34.24%of essential habitat was lost,mainly in highly suitable areas due to reclamation and waterway construction.Habitat degradation significantly affects female distribution and their reproductive processes,particularly gonad development during the pre-reproductive period and fecundity during the reproductive period,without altering population structure.These results indicated that the main ecological function served by the highly suitable breeding ground was the provision for development of gonad and improvement of fecundity.Increases of salinity and turbidity,caused by hydrodynamic changes from large-scale waterway construction,were identified as the environmental determinants contributing to cumulative habitat degradation.These influences ultimately led to a decrease in the fecundity of E.sinensis.Conclusions Our research sheds light on the quantification of habitat degradation in the Yangtze River Estuary and its implications for the reproduction process of E.sinensis,which can serve as a foundation for assessing and quantifying the ecosystem service values provided by these breeding grounds.This information is valuable for policymakers and resource managers in making informed decisions regarding habitat conservation and the sustainable utilization of fishery resources. 展开更多
关键词 Fishery habitat provision Breeding habitat degradation Reproductive process Estuarine ecosystem
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Identifying Key Descriptors for the Single-Atom Catalyzed CO Oxidation 被引量:1
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作者 Max J.Hülsey Sambath Baskaran +8 位作者 Shipeng Ding sikai wang Hiroyuki Asakura Shinya Furukawa Shibo Xi Qi Yu Cong-Qiao Xu Jun Li Ning Yan 《CCS Chemistry》 CAS 2022年第10期3296-3308,共13页
Fundamental knowledge of structure-activity correlations for heterogeneous single-atom catalysts(SACs)is essential in guiding catalytic design.While linear scaling relations are powerful for predicting the performance... Fundamental knowledge of structure-activity correlations for heterogeneous single-atom catalysts(SACs)is essential in guiding catalytic design.While linear scaling relations are powerful for predicting the performance of traditionalmetal catalysts,they appear to fail with the involvement of SACs.Comparing the catalytic CO oxidation activity of different atomically dispersed metals(3d,4d,and 5d)in conjunction with computational modeling enabled us to establish multiple scaling relations between the activity and simply calculated descriptors. 展开更多
关键词 scaling relations transition metals carbon monoxide single-site catalysts POLYOXOMETALATE
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Status of aquatic organisms resources and their environments in Yangtze River system(2017-2021)
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作者 Haile Yang Li Shen +104 位作者 Yongfeng He Huiwu Tian Lei Gao Jinming Wu Zhigang Mei Nian Wei Lin wang Tingbing Zhu Feifei Hu Jinling Gong Hongchun Du Xinbin Duan Huatang Deng Daoqun wang Fengyue Zhu Yunfeng Li Fan Wu Huijun Ru Yan Zhang Junyi Li Junlin Yang Yuntao Zhou Dongdong Fang Yinping wang Danqing Lin Yanping Yang Peijie Li Silei Liu Jian Yang Ping Zhuang sikai wang Tao Zhang Gang Yang Wenbo Yang Lilai Yuan Kun Cao Shuo Xu Huiyuan Liu Zhiqiang Liang Chongrui wang Hong Li Xiping Yuan Xin Yang Yilong Fu Yanping Zhang Haixin Zhang Zhiying Tao Sheng wang Xiaoping Gao Binsong Jin Kemao Li Guojie wang Shenglong Jian Yingqin Li Chenjiang Xue Chunyun Lei Shaowei Xue Yi Sun Bin Zhu Ke Shao Xingkun Hu Meihua Xiong Jun Du Bin He Tao Yan Yingying Huang Yuanchao Zou Biwen Xie Yongming wang Bin Li Fei Liu Yaoyao Zhang Fei Fan Zhijian wang Jing Huang Haoran Gu Hailong Ge Yan Dan Yan Li Shuqiao wang Chuang Zhang Lu Zhou Xue wang Sheng Zeng Yan Xiang Xugang He Jianhui Qin Chengxing Xia Jie Hou Yifu Shi Lifang Gao Zhiqiang Zhu Hongbao Shen Yun Du Xuejun Duan Jiawu Xiong Deguo Yang Shaoping Liu Zhaohui Ni Hui Zhang Kai Liu Feng Zhao Yingren Li Jianwei wang Qiwei Wei 《Aquaculture and Fisheries》 2024年第5期833-850,共18页
The Yangtze River is the mother river of China.To promote the aquatic ecosystem protection of the great river,the Project of Yangtze Fisheries Resources and Environment Investigation(2017-2021)supported by the Ministr... The Yangtze River is the mother river of China.To promote the aquatic ecosystem protection of the great river,the Project of Yangtze Fisheries Resources and Environment Investigation(2017-2021)supported by the Ministry of Agriculture and Rural Affairs,P.R.China carried out by 24 institutes and universities that located in the Yangtze River basin surveys the status of(1)fish species composition and spatial distribution,(2)current fish abundance,(3)endangered fishes,(4)Yangtze finless porpoise,(5)aquatic eco-environments,(6)water-level fluctuation areas,(7)capture fisheries and recreational fisheries of the Yangtze River mainstream and 10 of its main tributaries,including Yalong River,Heng River,Min River(including Dadu River),Chishui River,Tuo River,Jialing River,Wu River,Han River,Dongting Lake and Poyang Lake.The results showed that there were 443 fish species(belonging to 163 genus,37 families,and 18 orders)before 2017,but only 323 fish species(including 15 new recorded exotic species)were recorded in the project of 2017-2021.Among them,Cyprinus carpio,Carassius auratus,Hypophthalmichthys molitrix,Pelteobagrus fulvidraco,Coilia brachygnathus,Silurus asotus,Saurogobio dabryi,Ctenopharyngodon idellus,Pelteobagrus nitidus,Hemiculter leucisculus,Siniperca chuatsi,Coreius heterodon,Culter alburnus,Parabramis pekinensis,and Aristichthys nobilis were the dominant species across the whole Yangtze River system.It is estimated that there were 886 million individuals weighing 124.8 million kg,merely equivalent to 27.3%of the resources in 1950s,30.9%of the resources in 1960s,or 58.7%of the resources in 1980s.In the new list of protected fishes that recorded in the Yangtze River system,only 15 of 29 were collected in this project of 2017-2021.Psephurus gladius has been affirmed to be Extinct by International Union for Conservation of Nature(IUCN).The wild individuals of Tenualosa reevesii and Luciobrama macrocephalus have disappeared for many years and maybe have been extinct already.Acipenser dabryanus has been affirmed to be Extinct in the Wild by IUCN.The natural propagations of A.sinensis,Myxocyprinus asiaticus and Trachidermus fasciatus have been interrupted for many years.The populations of Yangtze finless porpoise in the Yangtze River mainstream,Dongting Lake and Poyang Lake have steadily rising sizes and expanding distributions in 2017-2021.Parts of them migrate from one region to another with the seasons,which would result in the fluctuation of Yangtze finless porpoise population within some regions.The conventional indicators of water quality in the Yangtze River system were good and conformed to the water quality criteria of fishery in 2017-2021.In the last 40 years,the maximum surface water area in the Yangtze River basin extended to approximately 63,360 km2,the minimum surface water area covered approximately 26,396 km2,and the seasonal water-level fluctuation areas occupied approximately 36,964 km2.Compared with 1984-2000 period,the 2001-2020 period witnessed an overall decreasing trend in the frequency of surface water occurrence within about 25,869 km2 of aquatic areas.From 1984 to 2000 period to 2001-2020 period,permanent surface water has decreased by nearly 8,750 km2.In 2017,the fishermen were mainly 40-60 years old and their educational levels were mainly lower than junior high school.In 2017,most anglers were older than 40 and used hand rod and/or sea rod.Their average catch of each time was mainly less than 1 kg.Results suggested that the fishing ban in key waters of the Yangtze River basin is not only an ecological project of aquatic ecosystem conservation,but also a livelihood project for the fisherman to embrace industrial transformation and improve their living conditions.After the implementation of the fishing ban,the fisheries resources would gradually recover,and the Yangtze finless porpoise population size would also see a steady increase.However,the endangered species would remain threatened for a long time.The degraded waterbodies and water-level fluctuation areas would be the key restrictive factors for future aquatic ecosystem recovery in the Yangtze River basin.Since this survey was carried out before the fishing ban,the current results could provide a baseline for future evaluation of the effect of the Yangtze River fishing ban. 展开更多
关键词 Fishes Yangtze finless porpoise Resources Aquatic ecosystem Fisheries Background investigation Yangtze river system
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