检索结果-南通市图书馆

Meteorological and Environmental Research 2023年第4期14卷 59-62页

作者： Zhen CHEN Xiaofeng LUO Jixi LIU Ziqin GAO Yixian QIU Xiaoning ZHANG Lingjin KONG Chunliang ZHANG Guangdong Yuedian Dianbai Wind Power Co. Ltd.Maoming 525400China Guangdong Yuedian Yangjiang Offshore Wind Power Co. Ltd.Yangjiang 510630China Henan Wangding Lightning Protection Device Safety Testing Co. Ltd.Zhengzhou 450003China Guangdong Foshan Shunde Lunjiao Jindun Lightning Protection Technology Development Co. Ltd.Foshan 528308China

Since ancient times,lightning disasters have undoubtedly been an unstoppable threat to *** thunderstorms,lightning often damages objects on the ground,such as buildings and *** Franklin invented the lightning rod in 1752,lightning rods have been used worldwide to prevent direct lightning strikes in various fields such as high-voltage power transmission lines,outdoor chemical sites,highways,land and sea wind farms,and forest lightning fire *** has been proven that lightning accidents still occur frequently in places where lightning rods are installed and the protective angle method is *** order to further study the protective effect of lightning rods and identify the shortcomings of lightning rod protection,negative lightning strikes are taken as the research object,to analyze the limitations of lightning rods in preventing direct lightning strikes from the working principle of lightning rods.

关键词： Lightning rod Direct lightning strike Protective angle method limitation

Work entransy and its applications

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2015年第12期58卷 2097-2103页

作者： CHENG XueTao LIANG XinGang Key Laboratory for Thermal Science and Power Engineering of Ministry of Education School of Aerospace Tsinghua University

The entransy theory has been applied to the analyses of heat-work conversion systems. The physical meaning and the applications of work entransy are analyzed and discussed in this paper. Work entransy, which is clarified to be a process dependent quantity, is not the entransy of work, but the system entransy change accompanying work transfer. The relationship between the work entransy and the output work is set up. When the application preconditions are satisfied, larger work entransy leads to larger output work. Entransy loss, which was proposed and applied to heat work conversion processes with irreversible heat transfer, is the net entransy flow into the system and the summation of work entransy and entransy dissipation. The application preconditions of entransy loss are also discussed.

关键词： work entransy entransy loss thermodynamic processes application limitation

Clinical Relevance of Coronary Fractional Flow Reserve： Art-of-state

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2015年第10期128卷 1399-1406页

作者： Yohanes Adiputra Shao-Liang Chen Department of Cardiology Nanjing First Hospital of Nanjing Medical University Nanjing Jiangsu 210006 China

Objective：The objective was to delineate the current knowledge of fractional flow reserve （FFR） in terms of definition,features,clinical applications,and pitfalls of measurement of *** Sources：We searched database for primary studies published in *** database of National Library of Medicine （NLM）,MEDLINE,and PubMed up to July 2014 was used to conduct a search using the keyword term ＂FFR＂.Study Selection：The articles about the definition,features,clinical application,and pitfalls of measurement of FFR were identified,retrieved,and ***：Coronary pressure-derived FFR rapidly assesses the hemodynamic significance of individual coronary artery lesions and can readily be performed in the catheterization *** use of FFR has been shown to effectively guide coronary revascularization procedures leading to improved patient ***：FFR is a valuable tool to determine the functional significance of coronary *** combines physiological and anatomical information,and can be followed immediately by percutaneous coronary intervention （PCI） if *** technique of FFR measurement can be performed easily,rapidly,and safely in the catheterization *** systematic use of FFR in dubious stenosis and multi-vessel disease,PCI can be made an even more effective and better treatment than it is *** current clinical evidence for FFR should encourage cardiologists to use this tool in the catheterization laboratory.

关键词： Clinical Application Features: Fractional Flow Reserve limitation

Pitfalls of acid leaching method for determining organic and inorganic carbon contents in marine sediments

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2020年第8期39卷 96-102页

作者： Chen Ling Zhifei Liu Jingwen Zhang Yulong Zhao Yanwei Zhang Adrian RFernandez State Key Laboratory of Marine Geology Tongji UniversityShanghai 200092China

Organic and inorganic carbon contents of marine sediments are important to reconstruct marine productivity,global carbon cycle, and climate change. A proper method to separate and determine organic and inorganic carbons is thus of great necessity. Although the best method is still disputable, the acid leaching method is widely used in many laboratories because of its ease-of-use and high accuracy. The results of the elemental analysis of sediment trap samples reveal that organic and inorganic carbon contents cannot be obtained using the acid leaching method, causing an infinitely amplified error when the carbon content of the decarbonated sample is 12%±1% according to a mathematical derivation. Acid fumigation and gasometric methods are used for comparison, which indicates that other methods can avoid this problem in organic carbon analysis. For the first time, this study uncovers the pitfalls of the acid leaching method, which limits the implication in practical laboratory measurement, and recommends alternative solutions of organic/inorganic carbon determination in marine sediments.

关键词： marine sediments organic carbon inorganic carbon acid leaching method limitation

Metabolomics reveals the key role of oxygen metabolism in heat susceptibility of an alpine-dwelling ghost moth, Thitarodes xiaojinensis (Lepidoptera: Hepialidae)

在线全文

学校读者我要写书评

暂无评论

Insect Science 2019年第4期26卷 695-710页

作者： Wei Zhu Qian Meng Huan Zhang Meng-Long Wang Xumn Li Hong-Tuo Wang Gui-Ling Zhou Lin Miao Qi-Lian Qin Ji-Hong Zhang State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of Zoology Chinese Academy of Sciences Beijing China Department of Herpetology Chengdu Institute of Biology Chinese Academy of Sciences Chengdu China

Ghost moths inhabiting the alpine meadows of the Tibetan Plateau are cold? adapted stenothermal organisms that are susceptible to heat (dead within 7 days at 27 °C exposure). Exploring the metabolic basis of their heat susceptibility would extend our understanding of the thermal biology of alpine-dwelling invertebrates. Here, gas chromatography-mass spectrometry-based metabolomics was combined with physiological and transcriptional approaches to determine the metabolic mechanisms of heat susceptibility in Thitarodes xiaojinensis larvae. The metabolomics results showed that 27 °C heat stress impaired the Krebs cycle and lipolysis in T. xiaojinensis larvae, as demonstrated by the accumulation of intermediary metabolites. In addition, carbohydrate reserves were highly and exclusively consumed, and an anaerobic product, lactate, accumulated. This evidence suggested a strong reliance on glycolysis to anaerobically generate energy. The respiration rate and enzymatic activity test results indicated a deficiency in O2 metabolism;in addition, the Krebs cycle capacity was not decreased, and the metabolic flux through aerobic pathways was limited. These findings were further supported by the occurrence of hypoxia symptoms in midgut mitochondria (vacuolation and swelling) and increased transcription of hypoxia-induced factor 1-α.Overall, heat stress caused O2 limitation and depressed the overall intensity of aerobic metabolism in ghost moths, and less efficient anaerobic glycolysis was activated to sustain their energy supply. As carbohydrates were depleted, the energy supply became deficient. Our study presents a comprehensive metabolic explanation for the heat susceptibility of ghost moths and reveals the relationship between O2 metabolism and heat susceptibility in these larvae.

关键词： energy metabolism ghost moths metabolomics thermal intolerance oxygen limitation respiration rate

In vitro iron enrichment experiments in the Prydz Bay, the Southern Ocean: A test of the iron hypothesis

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2009年第9期52卷 1426-1435页

作者： SUN Song PU XinMing ZHANG YongShan Key Laboratory of Marine Ecology and Environmental Sciences Institute of OceanologyChinese Academy of SciencesQingdao 266071China Marine Ecology Research Center First Institute of OceanographyState Oceanic AdministrationQingdao 266061China

In "high nitrate, low chlorophyll" (HNLC) ocean regions, iron has been typically regarded as the limiting factor for phytoplankton production. This "iron hypothesis" needs to be tested in various oceanic environments to understand the role of iron in marine biological and biogeochemical processes. In this paper, three in vitro iron enrichment experiments were performed in Prydz Bay and at the Polar Front north of the Ross Sea, to study the role of iron on phytoplankton production. At the Polar Front of Ross Sea, iron addition significantly (P0.05, Student's t-test) as a consequence of iron addition was observed. These results confirmed the limiting role of iron in the Ross Sea and indicated that iron was not the primary factor limiting phytoplankton growth in Prydz Bay. Because the light environment for phytoplankton was enhanced in experimental bottles, light was assumed to be responsible for the rapid growth of phytoplankton in all treatments and to be the limiting factor controlling field phytoplankton growth in Prydz Bay. During the incubation experiments, nutrient consumption ratios also changed with the physiological status and the growth phases of phytoplankton cells. When phytoplankton growth was stimulated by iron addition, N was the first and Si was the last nutrient which absorption enhanced. The Si/N and Si/P consumption ratios of phytoplankton in the stationary and decay phases were significantly higher than those of rapidly growing phytoplankton. These findings were helpful for studies of the ma- rine ecosystem and biogeochemistry in Prydz Bay, and were also valuable for biogeochemical studies of carbon and nutrients in various marine environments.

关键词： iron limitation iron hypothesis Southern Ocean Prydz Bay nutrient consumption ratio

Carbon and Nitrogen Amendments Lead to Differential Growth of Bacterial and Fungal Communities in a High-pH Soil

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2018年第2期28卷 255-260页

作者： Pramod N. KAMBLE Erland BAATH Microbial Ecology Department of Biology Ecology Building Lund University Lund SE-223 62 (Sweden) Department of Environmental Sciences Savitribai Phule Pune University Pune 411007 (India)

Microbial growth in soil is mostly limited by lack of carbon (C). However, adding fresh, C-rich litter can induce nitrogen (N) limitation. We studied the effect of alleviating C and N limitation in high-pH (> 8) soils, soils expected to favor bacterial over fungal growth. Nitrogen limitation was induced by incubating soils amended with C-rich substrate (starch or straw) for 4 weeks. Limiting nutrients and the effects of alleviating limitation were then studied by adding C (as glucose) or N (as NH_4NO_3) and measuring microbial growth and respiration after 4 d. In non-amended, C-limited soils, adding C but not N increased both microbial respiration and bacterial growth. In N-limited, substrate-amended soils, adding C increased respiration, whereas adding N increased both microbial respiration and growth. Inducing N limitation by amending with straw was most easily detected in increased fungal growth after the addition of N, whereas with starch, only bacterial growth responded to alleviating N limitation. Compared to earlier results using a low-pH soil, the effect of substrate used to induce N limitation was more important than pH for inducing bacterial or fungal growth after alleviating N limitation. Furthermore, we found no evidence that alleviating N limitation resulted in decreased respiration concomitant with increased microbial growth in soil, suggesting no drastic changes in C use efficiency.

关键词： acetate incorporation into ergosterol carbon use efficiency leucine incorporation limiting nutrient microbial growth microbial respiration N limitation

Quantitative evaluation of Tibet’s resource and environmental carrying capacity

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2019年第7期16卷 1702-1714页

作者： WANG Liang LIU Hui Key Laboratory of Regional Sustainable Development Modeling Chinese Academy of SciencesBeijing 100101China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China Faculty of Geographical Science Beijing Normal UniversityBeijing 100875China College of Resource and Environment University of Chinese Academy of SciencesBeijing 100049China

This study identifies the carrying state and value of Tibet’s resource and environmental carrying capacity.A new theoretical framework is proposed for exploring the resource and environmental carrying capacity based on two perspectives of“growth limit”and“stability of Human-Earth relationship system”.On this basis,an ideal growth model that accords with the“short board”effect is established to predict the population *** results show that the holistic state of resource and environmental carrying capacity in Tibet is in *** 2010 to 2016,Tibet’s carrying state continued to decline,moreover,the negative forces still overwhelm the positive *** the resource reserves still have room for more population,the environmental capacity and ecological capacity have been ***,the Human-Earth relationship system is in an unstable *** scenarios that respond to different socioeconomic developments are implemented to predict the population limitation of resource and environmental carrying capacity in Tibet;thus,authors argue that Tibet should keep its population size within 4 million around *** research will provide reference for sustainable development and resources and environmental conservation in Tibet.

关键词： Population limitation Resources carrying capacity Environmental carrying capacity Short board effect Tibet

Critical slope gradient for compulsory abandonment of farmland on the hilly Loess Plateau

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第5期43卷 409-412页

作者： TANG Keli+1, ZHANG Keli 1,2 and LEI Aling 1,3 1. Institute of Soil and Water Conservation, Chinese Academy of Sciences, Yangling 712100, China 2. Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China 3. Water Resources C Institute of Soil and Water Conservation Chinese Academy of Sciences Yangling China Department of Hydraulic Engineering Tsinghua University Beijing China Water Resources Conservation Bureau of Yangtze River Ministry of Water Resources Wuhan China

Scientific evidence for the upper limit of farmland is proposed. Shallow gully erosion is one of erosion types distributed extensively on sloping farmland in the hilly regions of the Loess Plateau. Field observation and aerial photos interpretation, as well as laboratory experiments show that the shallow gully erosion occurring on the steeper farmland in the hilly regions of the Loess Plateau is an important factor leading to intensive erosion on slope, because of its extensive distribution and intensive runoff collection. The data on the formation, development and distribution of shallow gullies on sloping farmland indicate that critical slope gradient for shallow gully initiation ranges from 15 to 20 degrees with an average of 18.2 degrees. Therefore, it is suggested that critical slope gradient for compulsory abandonment of farmland on the hilly Loess Plateau should be kept within the critical slope gradient for shallow gully initiation to prevent shallow gully formation in order to control soil loss more effectively. But as the first step, the cultivation on the slopes with slope larger than 25 degrees where the maximum erosion occurs should be strictly forbidden.

关键词： hilly region of Loess Plateau upper limitation for farmland shallow gully erosion erosion dynamic.