期刊文献+
共找到1,592篇文章
< 1 2 80 >
每页显示 20 50 100
Ontogenetic development in the morphology and behavior of loach(Misgurnus anguillicaudatus) during early life stages 被引量:9
1
作者 高雷 段明 +1 位作者 程飞 谢松光 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2014年第5期973-981,共9页
Loach (Misgurnus anguillicaudatus) is a commercially important fish in China and an ideal aquaculture species. However, culturists experience high larval and juvenile mortality during mass production. To provide ins... Loach (Misgurnus anguillicaudatus) is a commercially important fish in China and an ideal aquaculture species. However, culturists experience high larval and juvenile mortality during mass production. To provide insight into ways to improve larviculture techniques, we describe the morphological characteristics and behavior of loach during the larval and early juvenile stages. Yolksae larvae ranged from 2.8 to 4.0 mm body length (BL) between days 0 to 4; preflexion larvae ranged from 3.6 to 5.5 mm BL between days 4 to 6; flexion larvae ranged from 4.8 to 8.1 mm BL between days 5 and 14; and post-flexion larvae ranged from 7. l to 15.7 mm BL between days 11 to 27; the minimum length and age of juveniles was 14.1 mm BL and 23 d, respectively. Loach are demersal from hatch through to the early juvenile stages. A suite of morphological characteristics (e.g., external gill filament and ventral mouth opening) and behavioral traits have developed to adapt to demersal living. We observed positive allometric growth in eye diameter, head length, head height, and pectoral fin length during the early larval stages, reflecting the priorities in the development of the organs essential for survival. Our results provide a basis for developing techniques to improve the survival of larval and juvenile loach during mass production. 展开更多
关键词 behavioral features larvae and juveniles morphological development Misgurnus anguillicaudatus
下载PDF
FRACTAL BEHAVIOR OF DEVELOPMENT OF PHASE SEPARATION AND CRYSTALLIZATION IN BLENDS OF NYLON-6 WITH SODIUM SALT OF ETHYLENE /METHACRYLIC ACID COPOLYMER
2
作者 韩蕴萍 盛京 李著萍 《Transactions of Tianjin University》 EI CAS 1999年第2期93-97,共5页
Phase separation was studied by the optical microscopy in blends of nylon 6 (PA6) with sodium salt of ethylene/methacrylic acid copolymer (PEMA).The image collecting technology was used to keep track of the developme... Phase separation was studied by the optical microscopy in blends of nylon 6 (PA6) with sodium salt of ethylene/methacrylic acid copolymer (PEMA).The image collecting technology was used to keep track of the development of blends at a certain temperature.The fractal dimension of phase separation was calculated by the image solving technology according to the fractal theory and the self similarity behavior of the process was proved.The relationship of the fractal behavior with composition and experimental temperature was discussed.The fractal behavior of the crystallization development of the crystal phase of PA6 in blends was also discussed and the fractal behavior calculated. 展开更多
关键词 phase separation of nylon 6 blends fractal behavior of phase separation fractal behavior of development of crystallization
下载PDF
Phase Transitions and Seepage Characteristics during the Depletion Development of Deep Condensate Gas Reservoirs
3
作者 Qiang Liu Rujun Wang +6 位作者 Yintao Zhang Chong Sun Meichun Yang Yuliang Su Wendong Wang Ying Shi Zheng Chen 《Energy Engineering》 EI 2024年第10期2797-2823,共27页
Deep condensate gas reservoirs exhibit highly complex and variable phase behaviors,making it crucial to understand the relationship between fluid phase states and flow patterns.This study conducts a comprehensive anal... Deep condensate gas reservoirs exhibit highly complex and variable phase behaviors,making it crucial to understand the relationship between fluid phase states and flow patterns.This study conducts a comprehensive analysis of the actual production process of the deep condensate gas well A1 in a certain oilfield in China.Combining phase behavior analysis and CMG software simulations,the study systematically investigates phase transitions,viscosity,and density changes in the gas and liquid phases under different pressure conditions,with a reservoir temperature of 165°C.The research covers three crucial depletion stages of the reservoir:single-phase flow,two-phase transition,and two-phase flow.The findings indicate that retrograde condensation occurs when the pressure falls below the dew point pressure,reachingmaximum condensate liquid production at around 25MPa.As pressure decreases,gas phase density and viscosity gradually decrease,while liquid phase density and viscosity show an increasing trend.In the initial single-phase flow stage,maintaining a consistent gas-oil ratio is observed when both bottom-hole and reservoir pressures are higher than the dew point pressure.However,a sudden drop in bottom-hole pressure below the dew point triggers the production of condensate oil,significantly reducing subsequent gas and oil production.In the transitional two-phase flow stage,as the bottom-hole pressure further decreases,the reservoir exhibits a complex flow regime with coexisting areas of gas and liquid.In the subsequent two-phase flow stage,when both bottom-hole and reservoir pressures are below the dew point pressure,a significant increase in the gas-oil ratio is observed.The reservoir manifests a two-phase flow regime,devoid of single-phase gas flow areas.For lowpressure conditions in deep condensate gas reservoirs,considerations include gas injection,gas lift,and cyclic gas injection and production in surrounding wells.Additionally,techniques such as hot nitrogen or CO_(2) injection can be employed to mitigate retrograde condensation damage.The implications of this study are crucial for developing targeted development strategies and enhancing the overall development of deep condensate gas reservoirs. 展开更多
关键词 Deep condensate gas reservoirs depletion development phase behavior percolation laws dynamic production analysis
下载PDF
Peer educator training program for enhancing knowledge on issues in the growth and development of adolescents and risk behavior problems in Indonesian context
4
作者 Tantut Susanto lis Rahmawati Wantiyah 《Frontiers of Nursing》 CAS 2018年第3期185-191,共7页
Objective: This article aimed to evaluate the effects of an educational intervention programme on improving peer educator (PE) knowledge in issues around growth and development and its risk behavior problems of ado... Objective: This article aimed to evaluate the effects of an educational intervention programme on improving peer educator (PE) knowledge in issues around growth and development and its risk behavior problems of adolescents in Indonesia. Methods: The study was conducted in 31 of PEs to evaluate their knowledge in adolescents. The PEs received health education and were assessed by individual work during the structured three-week programme. Data were collected before and after the training programme as pre- and post-tests. Results: The PE demonstrated significant improvements in their knowledge after attending the three-week structured training programme. The post-test scores had significant effects on the dimensions of PE knowledge scores. The PE become knowledgeable to maintain and monitor adolescents health issues around growth and development and its risk behavior problems of adolescents. Conclusions: The PE become knowledgeable to respond to the adolescent problems and readiness to become PE during puberty. 展开更多
关键词 peer educator adolescent development risk behavior assertive
下载PDF
Analysis on Behavior Characteristics of Tourists under Perspective of Sustainable Development of Tourism Destinations: A Case Study of Mugecuo Scenic Area in Kangding City of Sichuan Province
5
作者 HE Ailin WANG Xiao 《Journal of Landscape Research》 2019年第5期146-148,共3页
Tourists are the subject of tourism activity,and it is conducive to promoting sustainable development of tourism destination by studying their behavior characteristics and tourism perception.Mugecuo Scenic Area in Kan... Tourists are the subject of tourism activity,and it is conducive to promoting sustainable development of tourism destination by studying their behavior characteristics and tourism perception.Mugecuo Scenic Area in Kangding City,Ganzi Tibetan Autonomous Prefecture,Sichuan Province is taken as research case,and visitors and managers in the scenic area are surveyed by using semi-structured interview method.Based on survey data,the research aims to put forward corresponding policy suggestions for sustainable development of Mugecuo Scenic Area by deeply analyzing tourists’ access to information of scenic area,tourists’ travel purpose,tourists’ satisfaction with services of scenic area and willingness to revisit. 展开更多
关键词 SUSTAINABLE development of TOURISM DESTINATION behavior characteristics of TOURISTS Mugecuo
下载PDF
The Separate Development of Children’s Listener and Speaker Behavior and the Intercept as Behavioral Metamorphosis
6
作者 R. Douglas Greer Peter Pohl +1 位作者 Lin Du Jennifer Lee Moschella 《Journal of Behavioral and Brain Science》 2017年第13期674-704,共31页
The study of verbal behavior focuses on communicative functions of the speakers/producers as they affect the behavior of listeners/observers. Effects on the listener reinforce the speaker and the listener/observer ben... The study of verbal behavior focuses on communicative functions of the speakers/producers as they affect the behavior of listeners/observers. Effects on the listener reinforce the speaker and the listener/observer benefits (i.e., is reinforced) from the behavior of the speaker/producer. The interlocking of, and exchange of, the speaker and listener behavior between individuals and within one’s own skin constitute bidirectional operants. These bidirectional operants are instances of social interactions and measures of social behavior. Evidence suggests that the act of listening, among other observing responses, is initially developmentally independent from speaker behavior. How they become joined parallels the biological phenomenon of metamorphosis. The succession of changes has been empirically identified as a succession of verbal behavior development cusps, which are described in their sequence biologically as a manifestation of functional metamorphosis. The onset of a cusp constitutes first instances of behavior and accompanying stimulus control that allows infants and children to contact parts of the environment for the first time resulting in their learning things impossible to learn before or learning faster. Cusps for the intercept of the speaker and listener lead to bidirectional operants and provide explanations for how children incidentally learn the names of things, become increasingly social, and make subsequent complex behavior possible. Many of the cusps identified in our research resulted from the missing behavior and stimulus control of children with autism. Once cusps were established, these children learned things they could not learn before, learned faster, and learned by contacting parts of the social environment they could not contact before. These findings led to a theory of verbal behavior development that point to the selection of bidirectional operants as behavioral phenotypes during functional metamorphosis, which has enhanced the survival of Homo sapiens through emergent symbolic skills for more effective collaboration between two or more individuals. 展开更多
关键词 Bidirectional OPERANT Verbal behavior development Comprehensive
下载PDF
Review of Problems of Adolescent Sexual Behavior and the Role of Millennium Development Goals 4, 5 and 6 in Nigeria
7
作者 Prosper Adogu Ifeoma Udigwe +1 位作者 Gerald Udigwe Chika Ubajaka 《International Journal of Clinical Medicine》 2014年第15期940-948,共9页
Introduction: The problems of adolescents’ sexual behavior are grave and far-reaching. Methods: Review of exiting literature via Google scholar, AJOL, Pubmed, HINARI and other relevant data bases on the common proble... Introduction: The problems of adolescents’ sexual behavior are grave and far-reaching. Methods: Review of exiting literature via Google scholar, AJOL, Pubmed, HINARI and other relevant data bases on the common problems of adolescents’ inappropriate sexual behavior. Result: Adolescent sexual behavior could result in adolescent pregnancy which prevalence varies widely throughout Nigeria perhaps due to differences in culture and development. Abortion, the willful termination of pregnancy is another problem which is often undertaken for pregnancies resulting from incest and sexual abuse. Also common is trans-generational sex which occurs when an adolescent has non-marital sex in the last 12 months with a man who is at least 10 years older than her. Also related to this, is transactional sex found in both committed and casual relationships. It is not always done for survival because in some cultures, sex for favor is carried out for reasons other than subsistence. Furthermore, multiple sexual partners are the engagement in sex with more than one partner over a particular time frame. It may be sequential or concurrent. The high prevalence of these problems in Nigeria raises a question of the possibility of achieving the millennium development goals (MDGs) 4, 5 and 6 specifically targeted at reducing child mortality, improving maternal health and combating HIV/AIDS, malaria and other diseases respectively. Conclusion: Policies and strategies such as family life and HIV/AIDs education (FLHE) curriculum on adolescent reproductive health should be pursued with greater vigor in our secondary schools in addition to establishing HIV counseling centers and vocational training programs for out-of-school adolescents. WHO support and commitment to key action areas for countries and member states will build and strengthen their capacity to improve reproductive and sexual health. 展开更多
关键词 ADOLESCENT Sexual behavior MILLENNIUM development Goals 4 5 6 NIGERIA
下载PDF
Development and psychometric evaluation of the nurse behavior toward confirmed and suspected HIV/AIDS patients (NB-CSHAP) scale
8
作者 Janet Alexis De los Santos Norberto Milla +1 位作者 Cyruz Tuppal Leodoro Labrague 《Frontiers of Nursing》 2022年第1期103-113,共11页
There is a scarcity of literature discussing nurses’ behaviors toward caring for suspected or confirmed human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients. The development of a scal... There is a scarcity of literature discussing nurses’ behaviors toward caring for suspected or confirmed human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients. The development of a scale specific to measure nurses’ behaviors will allow health institutions to assess the disposition of their nurses in terms of HIV care. This study aims to present the rigors of developing and validating a reliable instrument to contextualize these nurses’ behaviors. This study utilized a sequential exploratory mixed method design to develop the NB-CSHAP scale. Thematic analysis was done on the qualitative data from the interviews with persons living with HIV/AIDS (PLHA) from which items were selected to be included in the scale. Exploratory factor analysis was utilized to extract the factors and Cronbach’s alpha was used to assess the reliability of the instrument. Four factors were extracted and are categorized as either caring or discriminatory behaviors. These include: (1) service-oriented, (2) openhanded, (3) perceptive, and (4) discriminatory. The scale has an internal consistency of 0.73. The scale shows acceptable psychometric properties, hence can be used to assess the nurses’ behaviors in caring for confirmed or suspected HIV clients. The scale may be used by health institutions to determine the quality of the patient care provided by their nurses to clients with confirmed or suspected HIV . 展开更多
关键词 caring behaviors HIV/AIDS care NURSING scale development sequential exploratory mixed method design
下载PDF
The Development and Operation Mechanism of the Colleges’E-class Network Ideological and Political Education Platform——Based on post-95 college students’social behavior characteristics
9
《福建教育学院学报》 2016年第10期F0003-F0003,共1页
Based on the investigation and analysis of the social behavior characteristics of post-95undergraduates, this paper puts forward the principle of sharing and building e-class platform and analyzes thedevelopment of th... Based on the investigation and analysis of the social behavior characteristics of post-95undergraduates, this paper puts forward the principle of sharing and building e-class platform and analyzes thedevelopment of the functions of the four platforms such as the teacher-student service system, instant interactionsystem, SNS community system and vertical segmental pushing system and the realization of the function of modularoperation. Finally, in order to ensure the stable operation of the E-class platform, four measures are put forward suchas the systematic construction of the system, the innovation of team work, the assessment of key performances and thecomprehensive guarantee, thus providing an external guarantee for the stable operation of the E-class platform. 展开更多
关键词 college student network social interaction behavior CHARACTERISTICS development of E-CLASS platform operation GUARANTEE
下载PDF
THE STUDY OF EARLY DEVELOPMENT AND EVOLUTION OF Torrentophryne aspinia 被引量:3
10
作者 饶定齐 杨大同 《Zoological Research》 CAS CSCD 1994年第S1期142-157,200,共17页
Torrentophryne aspinia is a new kind of toads discovered in China recently, it lives in the forest floor in West Yunnan, the most important things for this kind of species is that they have a kind of torrent-adapted t... Torrentophryne aspinia is a new kind of toads discovered in China recently, it lives in the forest floor in West Yunnan, the most important things for this kind of species is that they have a kind of torrent-adapted tadpoles which have abdominal suckers and can adhere to the surfaces of rocks in moving waters. In this article, we described the forming procedures of abdominal sucker and some breeding behaviors, habitats and habits. After comparing with those of other toads, it is confirmed that Torrentophryne should be a new valid genus, it is derived from ancestor toads because of adaptation to the torrent habitats, by the forming of torrent -adapted organ-abdominal sucker in the early development. 展开更多
关键词 Torrentophryne aspinia HABITAT Breeding behavior TADPOLE Early development Adhesive organ Abdominal sucker
下载PDF
A DSS DEVELOPMENT AND APPLICATION FOR SUSTAINABLE DEVELOPMENT
11
作者 沈惠璋 王浣尘 +2 位作者 刘铎 亢政刚 丁雷 《Transactions of Tianjin University》 EI CAS 2000年第1期22-27,共6页
The characteristics of sustainable development problems in the developing countries is discussed.In order to develop and use decision support system (DSS) for supporting sustainable development problem decision making... The characteristics of sustainable development problems in the developing countries is discussed.In order to develop and use decision support system (DSS) for supporting sustainable development problem decision making in the developing countries,this paper presents a strategy of constructing the DSS for sustainable development.A methodology of representing the model of sustainable development problems and developing a nonprocedural modeling language that is used to define sustainable development problems,a methodology of numeric and non numeric operation based theorem proving is given in this paper. 展开更多
关键词 decision support system sustainable development qualitative analysis quantitative research evolution behaviors
全文增补中
Effects of florfenicol exposure on growth,development and antioxidant capacity of flounder Paralichthys olivaceus larvae at different developmental stages 被引量:2
12
作者 GUO Rui ZHANG Yingqi +4 位作者 ZHANG Xianyu ZHANG Qian CHENG Rui MD MOSTAFIZUR Rahman LIU Ying 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2020年第2期550-559,共10页
Antibiotics are widespread in various environmental media,and may pose a potential threat to aquatic ecosystems and non-target aquatic organisms.Florfenicol(FLO)is one of the most commonly used antibiotics in aquacult... Antibiotics are widespread in various environmental media,and may pose a potential threat to aquatic ecosystems and non-target aquatic organisms.Florfenicol(FLO)is one of the most commonly used antibiotics in aquaculture,and extensively used to substitute chloramphenicol with its strong sterilization and low adverse ef fect.In this study,flounder Paralichthys olivaceus,an important economic fish species in seawater was used as an experimental subject.Five exposure concentrations of FLO(including environmentrelated concentrations)were set at 0,0.01,0.1,1,and 10 mg/L.Ef fects of FLO exposure for 168 h on growth and development,motor behavior,antioxidant enzyme activity,malondialdehyde(MDA)content,and thyroid hormone level of P.olivaceus larvae were studied in pre-larvae(1 dpf)and post-larvae(20 dpf).The results show that the short-term FLO exposure could promote the larvae growth to some degrees,but inhibit them as the exposure time prolonged.For pre-larvae,FLO at 0.01 mg/L could stimulate the motor nerve system and increase the swimming ability,but inhibited it at 1 mg/L.With the increasing dosage of FLO,the superoxide dismutase(SOD)and MDA contents were elevated,reaching the maximum in the 1 mg/L FLO group.The pre-larvae were more sensitive than the post-larvae to FLO in the environment,and the growth and immune resistance could be damaged with long exposure.Post-larvae were more tolerant to external pollutants,FLO at 1 mg/L could promote the motor behavior and reduce SOD and MDA contents.Therefore,FLO can be used as an antibiotic at a proper concentration but as a drug to prevent disease in a long-term way. 展开更多
关键词 FLORFENICOL Paralichthys olivaceus larvae growth and development motor behavior antioxidant capacity
下载PDF
Early development of peer dominance relationships in a captive group of Japanese macaques Macaca fuscata 被引量:1
13
作者 RIZALDI Kunio WATANABE 《Current Zoology》 SCIE CAS CSCD 北大核心 2010年第2期190-197,共8页
We studied early development of peer dominance relationships in a captive group of Japanese macaques Macaca fuscata fuscata at the Primate Research Institute of Kyoto University. This study aims to give detailed descr... We studied early development of peer dominance relationships in a captive group of Japanese macaques Macaca fuscata fuscata at the Primate Research Institute of Kyoto University. This study aims to give detailed descriptions on characteristic patterns of maternal rank acquisition from infant to juvenile. Focal subjects were 22 young monkeys belonging to three cohorts born in 2002, 2003 and 2005. Data were collected with a total 2130 sessions of 30-minute continuous recording of focal subjects combined with all occurrence-sampling methods. The onset of aggressive behavior varied per cohort and was delayed in cohorts with fewer close-aged associates. More than 60% of dyadic combinations in agonistic interactions between peers were unidirectional throughout the study period. Although some bidirectional interactions could have involved unstable relationships between particular individuals, most of the bidirectional interactions included a few continuous series of alternating one-sided interactions. A linear order could be found among peers from the first appearance of aggressive behavior, and nearly 90% of those dyads were concordant with that of their mother's rank order. Young males were responsible for most of the dominance relations that would not be predicted based on their mother's rank. These results suggest that infant monkeys may recognize their own social status relative to their opponent's before onset of aggressive behavior and adjust themselves into the matrilineal rank system accordingly. 展开更多
关键词 Aggressive behavior Dominance relationship Early development Japanese macaque
下载PDF
PCDH17 restricts dendritic spine morphogenesis by regulating ROCK2-dependent control of the actin cytoskeleton,modulating emotional behavior 被引量:1
14
作者 Laidong Yu Fangfang Zeng +14 位作者 Mengshu Fan Kexuan Zhang Jingjing Duan Yalu Tan Panlin Liao Jin Wen Chenyu Wang Meilin Wang Jialong Yuan Xinxin Pang Yan Huang Yangzhou Zhang Jia-Da Li Zhuohua Zhang Zhonghua Hu 《Zoological Research》 SCIE CSCD 2024年第3期535-550,共16页
Proper regulation of synapse formation and elimination is critical for establishing mature neuronal circuits and maintaining brain function.Synaptic abnormalities,such as defects in the density and morphology of posts... Proper regulation of synapse formation and elimination is critical for establishing mature neuronal circuits and maintaining brain function.Synaptic abnormalities,such as defects in the density and morphology of postsynaptic dendritic spines,underlie the pathology of various neuropsychiatric disorders.Protocadherin 17(PCDH17)is associated with major mood disorders,including bipolar disorder and depression.However,the molecular mechanisms by which PCDH17 regulates spine number,morphology,and behavior remain elusive.In this study,we found that PCDH17 functions at postsynaptic sites,restricting the number and size of dendritic spines in excitatory neurons.Selective overexpression of PCDH17 in the ventral hippocampal CA1 results in spine loss and anxiety-and depression-like behaviors in mice.Mechanistically,PCDH17 interacts with actin-relevant proteins and regulates actin filament(F-actin)organization.Specifically,PCDH17 binds to ROCK2,increasing its expression and subsequently enhancing the activity of downstream targets such as LIMK1 and the phosphorylation of cofilin serine-3(Ser3).Inhibition of ROCK2 activity with belumosudil(KD025)ameliorates the defective F-actin organization and spine structure induced by PCDH17 overexpression,suggesting that ROCK2 mediates the effects of PCDH17 on F-actin content and spine development.Hence,these findings reveal a novel mechanism by which PCDH17 regulates synapse development and behavior,providing pathological insights into the neurobiological basis of mood disorders. 展开更多
关键词 Synapse development Dendritic spine Mood disorder Actin cytoskeleton Animal behavior
下载PDF
Evaluation of Several Phases in the Development of Management Accounting
15
作者 Chaomi Zhang Qinru Qian 《Journal of Modern Accounting and Auditing》 2005年第7期1-10,共10页
This paper discusses three issues, raised by Relevance Lost (Johnson & Kaplan, 1987), about historical evaluation of the development of management accounting. The first issue is when management accounting system wa... This paper discusses three issues, raised by Relevance Lost (Johnson & Kaplan, 1987), about historical evaluation of the development of management accounting. The first issue is when management accounting system was formed; the second is how to evaluate its development in subsequent decades; the third is how to evaluate the development of practice and research of management accounting in almost twenty years after Relevance Lost was published. The role of Relevance Lost in practice and theoretical research of management accounting is widely recognized, and the disagreement with it in this paper is in the specific area of the development history of management accounting. The authors of this paper believe that the development, through having its ups and downs over time, is generally speaking a continuous process, not separated by disconnected phases, leaping from one to another. Along with the progress in practice and research, researchers and practitioners are deepening their understanding about the theoretical foundation and practical development of management accounting. The history of development of management accounting is consistent with the process people gradually understand it. 展开更多
关键词 history of development of management accounting theory PRACTICE methods behavior
下载PDF
Nature or Nurture—On the Development of Children's Language
16
作者 席丽红 《科技信息》 2011年第19期I0255-I0255,共1页
Referring to children's development,especially the development of children's language,there is a question that people are very interested in,that is,does the development of children's language on earth dep... Referring to children's development,especially the development of children's language,there is a question that people are very interested in,that is,does the development of children's language on earth depend on innate inheritance or postnatal environment? In order to answer this question,this paper begins with the definition of the development of children's language,then,expounds some theories on language acquisition,finally,finds out the crucial factors influencing the development of children's language. 展开更多
关键词 英语教学 教学方法 阅读 翻译
下载PDF
河流鱼类诱驱理论及其在过鱼设施中的应用
17
作者 谭均军 孙钧键 石小涛 《水生生物学报》 北大核心 2025年第1期178-197,共20页
过鱼设施作为恢复鱼类洄游通道的重要生态补偿措施,已广泛应用于水生态保护,然而其过鱼效果尚未达到预期。诱驱鱼技术是提升过鱼设施过鱼效果的关键手段之一。结合近十年的室内与野外实验研究,文章系统阐述了水流、声、光、电、气泡幕... 过鱼设施作为恢复鱼类洄游通道的重要生态补偿措施,已广泛应用于水生态保护,然而其过鱼效果尚未达到预期。诱驱鱼技术是提升过鱼设施过鱼效果的关键手段之一。结合近十年的室内与野外实验研究,文章系统阐述了水流、声、光、电、气泡幕及生物因子等对鱼类行为的影响机制及诱驱理论,总结了诱驱鱼技术在过鱼设施中的应用优势与不足,得出结论:(1)鱼类对诱驱鱼因素的行为响应研究逐渐深入,由二维平面发展到三维空间(如由流速到流场、由声强到声场等);(2)诱驱鱼因素对不同鱼类的诱驱效果呈现种属共性和特异性,且不同大小鱼类对诱驱鱼因素也存在行为响应差异;(3)诱驱鱼技术研究对象逐渐由海洋鱼类转向淡水经济鱼类和保护鱼种,研究方法趋向于考虑多因子交互作用对鱼类行为的影响;(4)诱驱鱼技术的效果受多种因素交互影响,包括物种差异、工程布置适应性、运行管理等。未来研究应进一步解析多因子交互作用下的鱼类行为响应机制,优化适应不同过鱼设施运行条件的诱驱鱼设计,推动水生态保护的发展。 展开更多
关键词 水电开发 鱼类行为 过鱼设施 诱驱鱼技术 渔业保护
下载PDF
乳化沥青冷再生混合料强度特征与失效断裂演变机制研究进展
18
作者 邱欣 张丁川 +5 位作者 郭群英 项震宇 陈军 金钟声 赵晓瑜 吕会军 《浙江师范大学学报(自然科学版)》 CAS 2025年第1期12-20,共9页
“双碳”背景下,将乳化沥青冷再生混合料作为冷拌路面材料已受到道路工程界的广泛关注.针对乳化沥青冷再生混合料设计与应用中关键技术问题的研究进展进行了综述,系统地汇总了乳化沥青冷再生混合料在施工控制、强度发展机理和损伤行为特... “双碳”背景下,将乳化沥青冷再生混合料作为冷拌路面材料已受到道路工程界的广泛关注.针对乳化沥青冷再生混合料设计与应用中关键技术问题的研究进展进行了综述,系统地汇总了乳化沥青冷再生混合料在施工控制、强度发展机理和损伤行为特征3个方面的研究成果.混合料制备工艺方面,总结了目前国内外乳化沥青冷再生混合料生产工艺的相关技术,阐述了乳化沥青冷再生混合料的材料特性、拌和工艺、成型方式和养生条件等对其施工和易性的影响;混合料强度发展机理方面,阐明了乳化沥青冷再生混合料在不同影响因素下的微观结构特征,凝练了材料强度形成过程中的内部界面行为;混合料断裂失效行为特征方面,归纳了研究断裂行为和断裂机理的理论方法和实验手段,探讨了乳化沥青冷再生混合料的断裂机制与疲劳特性.研究表明:构建全面的材料组成特性认知体系,利用多尺度手段揭示乳化沥青冷再生混合料强度形成机理,实时动态感知混合料疲劳损伤过程的阶段性演化规律,将对改善乳化沥青冷再生混合料的力学性能和延长冷再生路面的使用寿命具有重要意义. 展开更多
关键词 乳化沥青 冷再生混合料 施工 强度发展 损伤行为
下载PDF
保定市城区0~5岁儿童体格发育、营养状况调查及超重、肥胖儿童饮食行为状况分析
19
作者 杜立燕 孟凡学 +2 位作者 范松丽 张英奎 高静 《发育医学电子杂志》 2025年第1期33-39,共7页
目的调查保定市城区0~5岁儿童的体格发育、营养状况,并分析超重、肥胖儿童的饮食行为状况。方法采用随机整群抽样方法,选取2019年1月至2022年12月于保定市城区妇幼保健机构体检的4319名0~5岁儿童为研究对象,分为0月龄(出生时)、1月龄、... 目的调查保定市城区0~5岁儿童的体格发育、营养状况,并分析超重、肥胖儿童的饮食行为状况。方法采用随机整群抽样方法,选取2019年1月至2022年12月于保定市城区妇幼保健机构体检的4319名0~5岁儿童为研究对象,分为0月龄(出生时)、1月龄、3月龄、6月龄、8月龄、12月龄、18月龄、2岁、2.5岁、3岁、4岁、5岁12个年龄组,测量身高、体质量,并与《2015年中国九市七岁以下儿童体格发育调查》(以下简称“中国九市”)的结果进行比较,评价儿童生长迟缓率、低体质量率、超重率、肥胖率。将本研究3~5岁年龄段检出的肥胖和超重儿童与正常儿童按照1∶1配对,采用中国学龄前儿童饮食行为量表(Chinese preschoolers'eating behavior questionnaire,CPEBQ)对儿童的饮食行为进行评价。统计学方法采用t检验。结果0~5岁各年龄组中,除6月龄、2岁及3岁年龄组的身高外,除12月龄、2.5岁及4岁年龄组的体质量外,男童身高和体质量均高于女童,差异均有统计学意义(P值均<0.05)。保定市城区0~5岁男女童体质量、身高均与“中国九市”城区标准持平,且生长趋势一致。在本研究调查的4319名0~5岁儿童中,生长迟缓59名(1.37%),低体质量49名(1.13%),超重287名(6.64%),肥胖164名(3.80%),其中各年龄段均存在超重和肥胖。3~5岁超重和肥胖儿童挑食、不良进食习惯、过饱响应、外因性进食CPEBQ评分均低于正常儿童,食物响应和主动进食CPEBQ评分均高于正常儿童,差异均有统计学意义(P值均<0.05)。结论保定市城区0~5岁儿童的体格发育状况良好,营养不良比例较低,但是超重率和肥胖率均较高,与儿童的不良饮食行为相关,应引起高度重视。 展开更多
关键词 儿童 生长发育 营养状况 肥胖 饮食行为
下载PDF
高价值专利知识网络嵌入与企业高质量发展:创业行为的调节作用
20
作者 彭华涛 韩一佳 范丹 《中国科技论坛》 北大核心 2025年第1期78-87,共10页
本文基于社会网络理论,选取CNIPA数据库中拥有高价值专利的288家上市公司为研究对象,探究高价值专利知识网络嵌入对企业高质量发展的影响以及创业行为在其中的调节作用。主要结论为:高价值专利知识网络关系嵌入、结构嵌入均正向影响企... 本文基于社会网络理论,选取CNIPA数据库中拥有高价值专利的288家上市公司为研究对象,探究高价值专利知识网络嵌入对企业高质量发展的影响以及创业行为在其中的调节作用。主要结论为:高价值专利知识网络关系嵌入、结构嵌入均正向影响企业高质量发展;组合创业行为、连续创业行为均正向调节高价值专利知识网络关系嵌入、结构嵌入与高质量发展之间的正向关系;国际创业行为增强高价值专利知识网络关系嵌入和企业高质量发展间的正向关系,但对高价值专利知识网络结构嵌入与企业高质量发展间的正相关关系不存在调节作用。此外,高价值专利知识网络嵌入对企业高质量发展的影响存在显著的企业所有制和行业竞争程度异质性。研究结论对于企业积极培育高价值专利、构建以高价值专利为核心的知识网络、实现企业高质量发展具有一定指导作用。 展开更多
关键词 高价值专利 知识网络嵌入 高质量发展 创业行为
下载PDF
上一页 1 2 80 下一页 到第
使用帮助 返回顶部