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Meningeal lymphatic vessel crosstalk with central nervous system immune cells in aging and neurodegenerative diseases
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作者 Minghuang Gao Xinyue Wang +5 位作者 Shijie Su Weicheng Feng Yaona Lai Kongli Huang dandan cao Qi Wang 《Neural Regeneration Research》 SCIE CAS 2025年第3期763-778,共16页
Meningeal lymphatic vessels form a relationship between the nervous system and periphery, which is relevant in both health and disease. Meningeal lymphatic vessels not only play a key role in the drainage of brain met... Meningeal lymphatic vessels form a relationship between the nervous system and periphery, which is relevant in both health and disease. Meningeal lymphatic vessels not only play a key role in the drainage of brain metabolites but also contribute to antigen delivery and immune cell activation. The advent of novel genomic technologies has enabled rapid progress in the characterization of myeloid and lymphoid cells and their interactions with meningeal lymphatic vessels within the central nervous system. In this review, we provide an overview of the multifaceted roles of meningeal lymphatic vessels within the context of the central nervous system immune network, highlighting recent discoveries on the immunological niche provided by meningeal lymphatic vessels. Furthermore, we delve into the mechanisms of crosstalk between meningeal lymphatic vessels and immune cells in the central nervous system under both homeostatic conditions and neurodegenerative diseases, discussing how these interactions shape the pathological outcomes. Regulation of meningeal lymphatic vessel function and structure can influence lymphatic drainage, cerebrospinal fluid-borne immune modulators, and immune cell populations in aging and neurodegenerative disorders, thereby playing a key role in shaping meningeal and brain parenchyma immunity. 展开更多
关键词 central nervous system meningeal lymphatic vessels IMMUNITY myeloid cells lymphatic cells neurodegenerative disease
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Development and optimization of object detection technology in pavement engineering: A literature review
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作者 Hui Yao Yaning Fan +7 位作者 Yanhao Liu dandan cao Ning Chen Tiancheng Luo Jingyu Yang Xueyi Hu Jie Ji Zhanping You 《Journal of Road Engineering》 2024年第2期163-188,共26页
Due to the rapid advancement of the transportation industry and the continual increase in pavement infrastructure,it is difficult to keep up with the huge road maintenance task by relying only on the traditional manua... Due to the rapid advancement of the transportation industry and the continual increase in pavement infrastructure,it is difficult to keep up with the huge road maintenance task by relying only on the traditional manual detection method.Intelligent pavement detection technology with deep learning techniques is available for the research and industry areas by the gradual development of computer vision technology.Due to the different characteristics of pavement distress and the uncertainty of the external environment,this kind of object detection technology for distress classification and location still faces great challenges.This paper discusses the development of object detection technology and analyzes classical convolutional neural network(CNN)architecture.In addition to the one-stage and two-stage object detection frameworks,object detection without anchor frames is introduced,which is divided according to whether the anchor box is used or not.This paper also introduces attention mechanisms based on convolutional neural networks and emphasizes the performance of these mechanisms to further enhance the accuracy of object recognition.Lightweight network architecture is introduced for mobile and industrial deployment.Since stereo cameras and sensors are rapidly developed,a detailed summary of three-dimensional object detection algorithms is also provided.While reviewing the history of the development of object detection,the scope of this review is not only limited to the area of pavement crack detection but also guidance for researchers in related fields is shared. 展开更多
关键词 Pavement engineering Object detection Lightweight network Attention mechanism Convolutional neural network
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Effect of Six Bacterial Strains on the Activity of Second Instar Larvae and Egg Hatching of Meloidogyne incognita
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作者 Jie LIU Li HE +4 位作者 Zixuan WANG Jianqing MA Xiaolong TONG dandan cao Gangyong ZHAO 《Plant Diseases and Pests》 2024年第5期15-18,共4页
[Objectives]The paper was to screen effective biocontrol strains against Meloidogyne incognita.[Methods]The effect of six bacterial strains sourced from the research group s strain library on the activity of second in... [Objectives]The paper was to screen effective biocontrol strains against Meloidogyne incognita.[Methods]The effect of six bacterial strains sourced from the research group s strain library on the activity of second instar larvae of M.incognita,as well as on egg hatching,was evaluated.[Results]The treatment of fermentation supernatant derived from the X-2 strain exhibited a pronounced lethal effect on M.incognita,with a corrected mortality rate reaching 97%within 72 h.Additionally,this treatment significantly inhibited egg hatching,achieving an inhibition rate of 94.69%at a 20-fold dilution.The strain was identified as Bacillus velezensis,belonging to the genus Bacillus,and was designated as RKN1111.[Conclusions]This study presents alternative strains and a theoretical framework for the biological control of M.incognita. 展开更多
关键词 Meloidogyne incognita Bacterial strain Second instar larvae Egg hatching
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Inhibition of fibroblast activation protein ameliorates cartilage matrix degradation and osteoarthritis progression 被引量:3
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作者 Aoyuan Fan Genbin Wu +18 位作者 Jianfang Wang Laiya Lu Jingyi Wang Hanjing Wei Yuxi Sun Yanhua Xu Chunyang Mo Xiaoying Zhang Zhiying Pang Zhangyi Pan Yiming Wang Liangyu Lu Guojian Fu Mengqiu Ma Qiaoling Zhu dandan cao Jiachen Qin Feng Yin Rui Yue 《Bone Research》 SCIE CAS CSCD 2023年第1期136-147,共12页
Fibroblast activation protein(Fap)is a serine protease that degrades denatured type I collagen,α2-antiplasmin and FGF21.Fap is highly expressed in bone marrow stromal cells and functions as an osteogenic suppressor a... Fibroblast activation protein(Fap)is a serine protease that degrades denatured type I collagen,α2-antiplasmin and FGF21.Fap is highly expressed in bone marrow stromal cells and functions as an osteogenic suppressor and can be inhibited by the bone growth factor Osteolectin(Oln).Fap is also expressed in synovial fibroblasts and positively correlated with the severity of rheumatoid arthritis(RA).However,whether Fap plays a critical role in osteoarthritis(OA)remains poorly understood.Here,we found that Fap is significantly elevated in osteoarthritic synovium,while the genetic deletion or pharmacological inhibition of Fap significantly ameliorated posttraumatic OA in mice.Mechanistically,we found that Fap degrades denatured type II collagen(Col II)and Mmp13-cleaved native Col II.Intra-articular injection of r Fap significantly accelerated Col II degradation and OA progression.In contrast,Oln is expressed in the superficial layer of articular cartilage and is significantly downregulated in OA.Genetic deletion of Oln significantly exacerbated OA progression,which was partially rescued by Fap deletion or inhibition.Intra-articular injection of r Oln significantly ameliorated OA progression.Taken together,these findings identify Fap as a critical pathogenic factor in OA that could be targeted by both synthetic and endogenous inhibitors to ameliorate articular cartilage degradation. 展开更多
关键词 CARTILAGE SUPERFICIAL inhibited
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Premature aging of skeletal stem/progenitor cells rather than osteoblasts causes bone loss with decreased mechanosensation 被引量:2
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作者 Ruici Yang dandan cao +6 位作者 Jinlong Suo Lingli Zhang Chunyang Mo Miaomiao Wang Ningning Niu Rui Yue Weiguo Zou 《Bone Research》 SCIE CAS CSCD 2023年第3期560-573,共14页
A distinct population of skeletal stem/progenitor cells(SSPCs)has been identified that is indispensable for the maintenance and remodeling of the adult skeleton.However,the cell types that are responsible for age-rela... A distinct population of skeletal stem/progenitor cells(SSPCs)has been identified that is indispensable for the maintenance and remodeling of the adult skeleton.However,the cell types that are responsible for age-related bone loss and the characteristic changes in these cells during aging remain to be determined.Here,we established models of premature aging by conditional depletion of Zmpste24(Z24)in mice and found that Prx1-dependent Z24 deletion,but not Osx-dependent Z24 deletion,caused significant bone loss.However,Acan-associated Z24 depletion caused only trabecular bone loss.Single-cell RNA sequencing(sc RNA-seq)revealed that two populations of SSPCs,one that differentiates into trabecular bone cells and another that differentiates into cortical bone cells,were significantly decreased in Prx1-Cre;Z24^(f/f)mice.Both premature SSPC populations exhibited apoptotic signaling pathway activation and decreased mechanosensation.Physical exercise reversed the effects of Z24depletion on cellular apoptosis,extracellular matrix expression and bone mass.This study identified two populations of SSPCs that are responsible for premature aging-related bone loss.The impairment of mechanosensation in Z24-deficient SSPCs provides new insight into how physical exercise can be used to prevent bone aging. 展开更多
关键词 SENSATION PROGENITOR mec
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Characteristics and expression of the TCP transcription factors family in Allium senescens reveal its potential roles in drought stress responses 被引量:1
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作者 XIAOHONG FU JIE ZHAO +5 位作者 dandan cao CHENGXING HE ZIYI WANG YIBEI JIANG JIANFENG LIU GUIXIA LIU 《BIOCELL》 SCIE 2023年第4期905-917,共13页
Allium senescens,is an important economic and ecological grassland plant with drought-resistant characteristics.A TCP protein transcription factor is important in the regulation of plant development and adverse respon... Allium senescens,is an important economic and ecological grassland plant with drought-resistant characteristics.A TCP protein transcription factor is important in the regulation of plant development and adverse responses.However,the mechanism by which TCP transcription functions in drought resistance in Allium senescens is still not clear.Here,we obtained a total of 190,305 transcripts with 115,562 single gene clusters based on RNA-Seq sequencing of Allium senescens under drought stress.The total number of bases was 97,195,096 bp,and the average length was 841.06 bp.Furthermore,we found that there were eight genes of the TCP family that showed an upregulated expression trend under drought stress in Allium senescens.We carried out an investigation to determine the evolution and function of the AsTCP family and how they produce an effect in drought resistance.The 14 AsTCP genes were confirmed and divided into class I and class II containing CIN and CYC/TBI subfamilies,respectively.We also found that the expression of AsTCP17 was remarkably upregulated with drought treatment.Besides,the transformation of AsTCP17 in Arabidopsis revealed that the protective enzymes,namely polyphenol oxidase(POD)and superoxide dismutase(SOD),were increased by 0.4 and 0.8 times,respectively.Chlorophyll content was also increased,while the H2O2 and malondialdehyde(MDA)contents were decreased.Staining assays with 3,3′-diaminobenzidine(DAB)also suggested that the AsTCP17 downregulates reactive oxygen species(ROS)accumulation.In addition,overexpression of the AsTCP17 affected the accumulation of drought-related hormones in plants,and the synthesis of ABA.The expression of AtSVP and AtNCED3,related ABA synthesis pathway genes,indicated that the level of expression of AtSVP and AtNCED3 was obviously enhanced,with the overexpression of line 6 showing a 20.6-fold and 7.0-fold increase,respectively.Taken together,our findings systematically analyze the AsTCPs family at the transcriptome expression level in Allium senescens,and we also demonstrated that AsTCP17 protein,as a positive regulator,was involved in drought resistance of Allium senescens.In addition,our research contributes to the comprehensive understanding of the drought stress defense mechanism in herbaceous plants. 展开更多
关键词 Allium senescens Drought stress TCP transcription factor ABA synthesis pathway
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“绿色电力”理念的应用化学人才培养研究与实践
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作者 孙振丽 曹丹丹 +2 位作者 金洁 方明 汪黎东 《大学化学》 CAS 2023年第3期34-39,共6页
能源电力的可持续发展是支撑我国未来经济社会高质量发展的首要任务,因此电力行业的人才培养不可或缺。在新工科建设背景下,华北电力大学作为电力行业卓越人才培养的摇篮,以电力产业需求为导向,率先提出并构建了基于“绿色电力”理念的... 能源电力的可持续发展是支撑我国未来经济社会高质量发展的首要任务,因此电力行业的人才培养不可或缺。在新工科建设背景下,华北电力大学作为电力行业卓越人才培养的摇篮,以电力产业需求为导向,率先提出并构建了基于“绿色电力”理念的复合型应用化学人才培养模式,并成功应用于本科教学改革与实践。使学生既掌握电力环保技术的应用背景和工程实践技能,又具备协同分析及解决复杂多污染物控制的创新能力,以培养新时代应用化学高素质人才,服务国家发展。 展开更多
关键词 绿色能源 产业需求 应用化学
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Comparative transcriptome analysis provides insights into the molecular mechanism of the anti-nematode role of Arachis hypogaea(Fabales:Fabaceae)against Meloidogyne incognita(Tylenchida:Heteroderidae)
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作者 XUEJIN YANG YUANYUAN ZHOU +4 位作者 XINYI PENG XIAOHONG FU JIANQING MA JIANFENG LIU dandan cao 《BIOCELL》 SCIE 2023年第9期2101-2113,共13页
Background:Plant root-knot nematode(RKN)disease is a serious threat to agricultural production across the world.Meloidogyne incognita is the most prominent pathogen to the vegetables and cash crops cultivated.Arachis ... Background:Plant root-knot nematode(RKN)disease is a serious threat to agricultural production across the world.Meloidogyne incognita is the most prominent pathogen to the vegetables and cash crops cultivated.Arachis hypogaea can effectively inhibit M.incognita,but the underlying defense mechanism is still unclear.Methods:In our study,the chemotaxis and infestation of the second-stage juveniles(J2s)of M.incognita to A.hypogaea root tips were observed by the Pluronic F-127 system and stained with sodium hypochlorite acid fuchsin,respectively.The transcriptome data of A.hypogaea roots with non-infected or infected by J2s were analyzed.Results:The J2s could approach and infect inside of A.hypogaea root tips,and the chemotactic migration rate and infestation rate were 20.72%and 22.50%,respectively.Differential gene expression and pathway enrichment analyses revealed ubiquinone and other terpenoid-quinone biosynthesis pathway,plant hormone signal transduction pathway,and phenylpropanoid biosynthesis pathway in A.hypogaea roots responded to the infestation of M.incognita.Furthermore,the AhHPT gene,encoding homogentisate phytyltransferase,was considered to be an ideal candidate gene due to its higher expression based on the transcriptome data and quantitative real-time PCR analysis.Conclusion:Therefore,the key gene AhHPT might be involved in the A.hypogaea against M.incognita.These findings lay a foundation for revealing the molecular mechanism of A.hypogaea resistance to M.incognita and also provide a prerequisite for further gene function verification,aiming at RKN-resistant molecular breeding. 展开更多
关键词 Arachis hypogaea Meloidogyne incognita Transcriptome data AhHPT gene
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The State-of-the-Art Review on Applications of Intrusive Sensing,Image Processing Techniques,and Machine Learning Methods in Pavement Monitoring and Analysis 被引量:14
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作者 Yue Hou Qiuhan Li +5 位作者 Chen Zhang Guoyang Lu Zhoujing Ye Yihan Chen Linbing Wang dandan cao 《Engineering》 SCIE EI 2021年第6期845-856,共12页
In modern transportation,pavement is one of the most important civil infrastructures for the movement of vehicles and pedestrians.Pavement service quality and service life are of great importance for civil engineers a... In modern transportation,pavement is one of the most important civil infrastructures for the movement of vehicles and pedestrians.Pavement service quality and service life are of great importance for civil engineers as they directly affect the regular service for the users.Therefore,monitoring the health status of pavement before irreversible damage occurs is essential for timely maintenance,which in turn ensures public transportation safety.Many pavement damages can be detected and analyzed by monitoring the structure dynamic responses and evaluating road surface conditions.Advanced technologies can be employed for the collection and analysis of such data,including various intrusive sensing techniques,image processing techniques,and machine learning methods.This review summarizes the state-ofthe-art of these three technologies in pavement engineering in recent years and suggests possible developments for future pavement monitoring and analysis based on these approaches. 展开更多
关键词 Pavement monitoring and analysis The state-of-the-art review Intrusive sensing Image processing techniques Machine learning methods
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PUM1 represses CDKN1B translation and contributes to prostate cancer progression 被引量:5
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作者 Xin Li Jian Yang +2 位作者 Xia Chen dandan cao Eugene Yujun Xu 《The Journal of Biomedical Research》 CAS CSCD 2021年第5期371-382,共12页
Posttranscriptional regulation of cancer gene expression programs plays a vital role in carcinogenesis;identifying the critical regulators of tumorigenesis and their molecular targets may provide novel strategies for ... Posttranscriptional regulation of cancer gene expression programs plays a vital role in carcinogenesis;identifying the critical regulators of tumorigenesis and their molecular targets may provide novel strategies for cancer diagnosis and therapeutics.Highly conserved RNA-binding protein Pumilio-1(PUM1)regulates mouse growth and cell proliferation,propelling us to examine its role in cancer.We found human PUM1 is highly expressed in a diverse group of cancer,including prostate cancer;enhanced PUM1 expression is also correlated with reduced survival among prostate cancer patients.Detailed expression analysis in twenty prostate cancer tissues showed enhanced expression of PUM1 at mRNA and protein levels.Knockdown of PUM1 reduced prostate cancer cell proliferation and colony formation,and subcutaneous injection of PUM1 knockdown cells led to reduced tumor size.Downregulation of PUM1 in prostate cancer cells consistently elevated cyclin-dependent kinase inhibitor 1B(CDKN1B)protein expression through increased translation but did not impact its mRNA level,while overexpression of PUM1 reduced CDKN1B protein level.Our finding established a critical role of PUM1 mediated translational control,particularly the PUM1-CDKN1B axis,in prostate cancer cell growth and tumorigenesis.We proposed that PUM1-CDKN1B regulatory axis may represent a novel mechanism for the loss of CDKN1B protein expression in diverse cancers and potential targets for therapeutics development. 展开更多
关键词 PUM1 prostate cancer posttranscriptional regulation CDKN1B
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Stromal cell decidualization and embryo implantation: a vulnerable step leading to successful pregnancy
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作者 Luhan Jiang Sudini R.Fernando +3 位作者 Suranga P.Kodithuwakku dandan cao William S.B.Yeung Kai-Fai Lee 《Reproductive and Developmental Medicine》 CAS CSCD 2024年第2期101-110,共10页
Endometrial stromal cell decidualization is a crucial step in endometrial remodeling during pregnancy.Decidualization is controlled by orchestrated ovarian hormones,followed by the activation of various downstream sig... Endometrial stromal cell decidualization is a crucial step in endometrial remodeling during pregnancy.Decidualization is controlled by orchestrated ovarian hormones,followed by the activation of various downstream signaling pathways.Accumulating evidence has shown multiple functions of decidualized endometrial stromal cells during embryo implantation,including tissue remodeling,antioxidative stress,angiogenesis,and immune tolerance.The distinct secretomes of decidualized stromal cells also reveal their intensive interactions with epithelial,endothelial,and immune cells.However,aberrant decidualization leads to pregnancy failures,such as recurrent pregnancy loss and repeated implantation failure.This review aimed to provide an overview of the molecular mechanisms underlying the divergent functions of decidualized endometrial stromal cells and their potential clinical applications.Moreover,the use of single-cell RNA sequencing data further enhances our understanding of these biological processes.This review discusses decidualization-related signaling pathways that serve as potential therapeutic targets for treating implantation failure in in vitro fertilization and provides novel approaches to investigate the underlying causes of female infertility. 展开更多
关键词 Endometrial stromal cell DECIDUALIZATION Embryo implantation Recurrent pregnancy loss Repeated implantation failure
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Minimal residual disease in solid tumors:an overview 被引量:1
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作者 Yarui Ma Jingbo Gan +2 位作者 Yinlei Bai dandan cao Yuchen Jiao 《Frontiers of Medicine》 SCIE CSCD 2023年第4期649-674,共26页
Minimal residual disease(MRD)is termed as the small numbers of remnant tumor cells in a subset of patients with tumors.Liquid biopsy is increasingly used for the detection of MRD,illustrating the potential of MRD dete... Minimal residual disease(MRD)is termed as the small numbers of remnant tumor cells in a subset of patients with tumors.Liquid biopsy is increasingly used for the detection of MRD,illustrating the potential of MRD detection to provide more accurate management for cancer patients.As new techniques and algorithms have enhanced the performance of MRD detection,the approach is becoming more widely and routinely used to predict the prognosis and monitor the relapse of cancer patients.In fact,MRD detection has been shown to achieve better performance than imaging methods.On this basis,rigorous investigation of MRD detection as an integral method for guiding clinical treatment has made important advances.This review summarizes the development of MRD biomarkers,techniques,and strategies for the detection of cancer,and emphasizes the application of MRD detection in solid tumors,particularly for the guidance of clinical treatment. 展开更多
关键词 MRD solid tumor CTC CTDNA
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加入《迁徙物种公约》,促进全球迁徙动物保护 被引量:5
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作者 蒋志刚 张正旺 +15 位作者 张润志 马志军 初红军 李义明 丁长青 赵亚辉 徐基良 平晓鸽 曾岩 崔绍朋 李娜 曹丹丹 王苏盆 徐婧 戚英杰 李春旺 《生物多样性》 CAS CSCD 北大核心 2019年第12期1393-1395,共3页
自然界中,一些野生动物为了觅食或繁殖,会随着季节沿固定或非固定路线从一处栖息地转换到另一处栖息地。这些野生动物常常跨越国界进行长距离的迁徙或洄游,其生存容易受到迁徙或洄游路线阻断、过度捕猎/捕捞、气候变化以及觅食或繁殖栖... 自然界中,一些野生动物为了觅食或繁殖,会随着季节沿固定或非固定路线从一处栖息地转换到另一处栖息地。这些野生动物常常跨越国界进行长距离的迁徙或洄游,其生存容易受到迁徙或洄游路线阻断、过度捕猎/捕捞、气候变化以及觅食或繁殖栖息地丧失和退化的威胁(Wilcove&Wikelski,2008)。 展开更多
关键词 栖息地丧失 迁徙动物 野生动物 气候变化 洄游 觅食 长距离
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中国阿勒泰地区鸟类物种编目、丰富度格局和区系组成 被引量:3
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作者 李娜 丁晨晨 +6 位作者 曹丹丹 初红军 戚英杰 李春旺 平晓鸽 孙悦华 蒋志刚 《生物多样性》 CAS CSCD 北大核心 2020年第4期401-411,共11页
中国阿勒泰地区位于新疆北部,与哈萨克斯坦、俄罗斯、蒙古国交界,该区包含阿尔泰山及山前荒漠和绿洲,属于全球200个生物多样性最丰富和最具代表性生态区之一的阿尔泰–萨彦岭生物热点地区。阿勒泰地区生境多样,鸟类物种资源丰富。尽管... 中国阿勒泰地区位于新疆北部,与哈萨克斯坦、俄罗斯、蒙古国交界,该区包含阿尔泰山及山前荒漠和绿洲,属于全球200个生物多样性最丰富和最具代表性生态区之一的阿尔泰–萨彦岭生物热点地区。阿勒泰地区生境多样,鸟类物种资源丰富。尽管以往曾在阿勒泰地区进行过一些鸟类调查,但对于该地区不同景观和生境类型中鸟类物种丰富度和分布尚无详尽报道。本文通过2013–2016年在中国境内阿尔泰山及山前平原地区对不同生境类型中的鸟类进行实地调查,并总结文献资料及观鸟爱好者的记录数据,重新整理了阿勒泰地区鸟类名录及地理分布,分析了鸟类的物种组成、区系成分;通过鸟类分布位点数据,选取气候、土地覆被类型、人类足迹指数及地形共4类环境因子作为自变量建立MaxEnt生态位模型,通过模拟77种鸟类的适宜分布区并叠加分布图层,获得了阿勒泰地区的鸟类物种丰富度分布格局。结果表明:阿勒泰共记录鸟类344种,隶属19目55科149属,其中雀形目163种。在垂直海拔带上,鸟类物种数分别为高山裸岩带24种,高山草甸带35种,山地森林草原带172种,低山灌木带130种,荒漠草原带84种,平原绿洲带173种,以及各海拔带的湿地与水域生境中水鸟92种;在区系成分上,以北方型鸟类为主(170种,占49.4%),其次为广布种(93种,占27.0%)。阿尔泰山地的鸟类区系呈现出西伯利亚动物区系特征,山前平原地区呈现蒙新区分布特征,因此,阿勒泰地区动物地理区系属于古北界欧洲–西伯利亚亚界阿尔泰–萨彦岭区阿尔泰亚区;山前平原地区属于古北界中亚亚界蒙新区西部荒漠亚区。Max Ent模型推测阿勒泰地区山前平原绿洲地区、山地森林草原带和低山灌木带具有较高的鸟类物种丰富度,尤其是额尔齐斯河流域下游的绿洲带宽阔,鸟类物种丰富,而高山区和荒漠生境中鸟类物种相对较少。模型预测的结果与实际调查情况相符。阿勒泰地区应采用生态友好的经济发展策略,加强对乔木和灌木的保护,这有助于维持较高的鸟类物种多样性。此外,降低生境破碎化不仅对该地区物种保护有重要作用,也对维持阿尔泰–萨彦岭生物热点地区的山地鸟类多样性有重要意义。 展开更多
关键词 中国阿勒泰 阿尔泰山 鸟类 生境类型 区系特征 物种丰富度
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The thermal transformation mechanism of chlorinated paraffins:An experimental and density functional theory study 被引量:1
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作者 Shanzhi Xin Wei Gao +5 位作者 dandan cao Kun Lv Yaquan Liu Chunyan Zhao Yawei Wang Guibin Jiang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2019年第1期378-387,共10页
The increasing production and usage of chlorinated paraffins(CPs) correspondently increase the amount of CPs that experience thermal processes. Our previous study revealed that a significant amount of medium-chain chl... The increasing production and usage of chlorinated paraffins(CPs) correspondently increase the amount of CPs that experience thermal processes. Our previous study revealed that a significant amount of medium-chain chlorinated paraffins(MCCPs), short-chain chlorinated paraffins(SCCPs) as well as aromatic and chlorinated polycyclic aromatic hydrocarbons(Cl-PAHs) were formed synergistically during the thermal decomposition of CP-52(a class of CP products).However, the transformation mechanisms of CP-52 to these compounds are still not very clear.This article presents a mechanistic analysis on the decomposition of CP-52 experimentally and theoretically. It was found that CP-52 initially undergoes dehydrochlorination and carbon chain cleavage and it transformed into chlorinated and unsaturated hydrocarbons. Cyclization and aromatization were the most accessible pathways at low temperatures(200–400°C), both of which produce mostly aromatic hydrocarbons. As the temperature exceeds 400°C, the hydrocarbons could decompose into small molecules, and the subsequent radical-induced reactions become the predominant pathways, leading to the formation of Cl-PAHs. The decomposition of CP-52 was investigated by using density functional theory and calculations demonstrating the feasibility and rationality of PCB and PCN formation from chlorobenzene. The results improve the understanding of the transformation processes from CP-52 to SCCPs and Cl-PAHs as well as provide data for reducing their emissions during thermal-related processes. 展开更多
关键词 DECOMPOSITION MECHANISM Chlorinated PARAFFINS Chlorinated AROMATIC hydrocarbons Density functional theory (DFT)
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社会信任与民营经济高质量发展——基于企业合作创新的视角 被引量:1
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作者 王文涛 曹丹丹 《中国会计评论》 2019年第4期689-714,共26页
合作创新是推动民营经济高质量发展的现实路径,但与独立创新相比更易受外部环境的影响。然而,普遍的社会信任机制尚未真正建立,成为社会治理框架中最为薄弱的环节。据此,本文基于世界银行的中国企业调查数据,实证检验社会信任对民营企... 合作创新是推动民营经济高质量发展的现实路径,但与独立创新相比更易受外部环境的影响。然而,普遍的社会信任机制尚未真正建立,成为社会治理框架中最为薄弱的环节。据此,本文基于世界银行的中国企业调查数据,实证检验社会信任对民营企业合作创新的治理效应。研究表明,社会信任通过融资机制、引资机制、共享机制和声誉机制激励了民营企业合作创新的意愿与强度。进一步研究发现,健全的法制环境能够促进民营企业合作创新,而社会信任在一定程度上弥补了法制环境尚未健全的不足。此外,社会信任具有明显的"差序格局"特征,而且只有基于市场机制形成的"生人信任"才能对民营企业合作创新产生显著的正向影响。因此,加强社会诚信建设,特别是法制和市场信任建设,有助于推动民营经济高质量发展。 展开更多
关键词 社会信任 合作创新 民营经济 高质量发展
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Speciation of organomercury compounds by capillary electrophoresis with pre-column derivatization and on-line stacking
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作者 dandan cao Yongguang Yin Bin He 《Chinese Chemical Letters》 SCIE CAS CSCD 2019年第3期650-652,共3页
Simultaneous separation and detection of three organomercury species, namely methylmercury(MeHg),ethylmercury(EtHg), and phenylmercury(PhHg), was performed by using capillary electrophoresis(CE)with UV detection. Pre-... Simultaneous separation and detection of three organomercury species, namely methylmercury(MeHg),ethylmercury(EtHg), and phenylmercury(PhHg), was performed by using capillary electrophoresis(CE)with UV detection. Pre-column derivatization with thiosalicylic acid and on-line salt-induced stacking significantly improved the detection performance. Buffer pH, ion strength, and additive were optimized for CE separation, concentration of NaCl in sample solution and injection time were optimized for on-line stacking. The limits of detection were 76.9,83.0 and 76.4 μg/L for PhHg, EtHg and MeHg, respectively. The developed method was validated by certified reference material and liquid chromatography-atomic fluorescence spectroscopy, which suggests this method could be useful in the speciation of organomercury compounds in biological samples. 展开更多
关键词 Capillary ELECTROPHORESIS Mercury SPECIATION DERIVATIZATION ON-LINE STACKING
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