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Experimental and numerical investigation on the deformation and breakup of water droplets in shear airflow
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作者 Jingxin WANG Yuan WANG +3 位作者 Ning ZHAO Chengxiang ZHU Hao DAI Chunling ZHU 《Science China(Technological Sciences)》 2026年第2期28-43,共16页
The dynamic behaviors of supercooled large water droplets(SLDs)in airflow involving deformation,breakup,and splash affect the local water collection coefficient,leading to an increase in the complexity of aircraft ici... The dynamic behaviors of supercooled large water droplets(SLDs)in airflow involving deformation,breakup,and splash affect the local water collection coefficient,leading to an increase in the complexity of aircraft icing.A parametric study on the influence of deformed water droplets in shear flow is investigated experimentally and numerically.A horizontal refrigerated wind tunnel is used to create the background shear airflow.A high-speed camera records the evolution of cross-stream/streamwise diameters and the breakup process.The level set method is employed to capture the deformation of micrometer-sized supercooled water droplets in continuous airflow.The deformation modes are categorized into five regimes:stabilization,vibration,transition,bag breakup,and bag-stamen breakup.A dimensionless deformation factor L is defined to describe the droplet deformation,which increases with airflow speed,droplet volume,and temperature.Applying the scaling expression Oh~(4.39)We~(0.85),a normalized acceleration model of water droplets in shear airflow is established.Based on the experimental results,a drag coefficient model for disc-shaped droplets within the transient Reynolds number range of 420-10000 is obtained.As the initial Weber number exceeds 9.5 and the maximum deformation factor exceeds 3.5,the droplet enters the breakup regime.Furthermore,bag-stamen breakup occurs when the initial Weber number exceeds 17.5. 展开更多
关键词 multiphase fluid dynamics deformation factor drag coefficient breakup regime level set
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Determination of Bioactive Potential in a Semi-domesticated Population of Oregano(Lippia graveolens Kunth)with Organic Fertilization
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作者 Priscilla Yamilhet Montes-Orona Mercedes Georgina Ramírez-Aragón +3 位作者 Isaela Villalpando-De La Torre Urbano Nava-Camberos Jared Ceniceros-García JoséLuis García-Hernández 《Phyton-International Journal of Experimental Botany》 2026年第2期22-35,共14页
Mexican oregano(Lippia graveolens Kunth)is an aromatic species of high culinary and medicinal relevance.In Mexico,more than 40 taxa with characteristic aroma and flavor are commercially recognized as oregano,with L.gr... Mexican oregano(Lippia graveolens Kunth)is an aromatic species of high culinary and medicinal relevance.In Mexico,more than 40 taxa with characteristic aroma and flavor are commercially recognized as oregano,with L.graveolens being the most widely distributed and economically important.Despite its relevance,few domesticated or semi-domesticated cultivars exist,and wild populations remain the main source of raw material,raising concerns regarding sustainability and quality standardization.The essential oil and oleoresins of L.graveolens possess recognized bioactivity,including antioxidant,antifungal,antibacterial,and anti-inflammatory properties,largely attributed to phenolic compounds such as thymol and carvacrol.Given the increasing global demand for natural bioactives and functional foods,optimizing cultivation practices is essential to enhance both the yield and phytochemical quality of this species.This study evaluated the effect of organic fertilization(0,5,10,and 15 t ha^(−1)of vermicompost)on the phenolic profile,flavonoid content,and antioxidant capacity of oregano oleoresin obtained from a semi-domesticated population across three harvests.The highest phenolic concentration(≈500 mg GAE g^(−1)extract)and greatest antioxidant activity(ABTS>3.5×10^(5)μmol TE g^(−1)extract)were observed at the 5 t ha^(−1)dose during the second harvest.Flavonoid content peaked in the third harvest(480-620 mg QE g^(−1)extract),whereas the unfertilized control exhibited the highest DPPH activity in the first harvest.Overall,the results indicate that vermicompost dosage and harvest timing substantially influence the functional quality of L.graveolens.Moderate organic fertilization,particularly 5 t ha^(−1),enhances the biosynthesis of bioactive secondary metabolites,underscoring its potential for sustainable production systems. 展开更多
关键词 Antioxidant capacity aromatic herbs OLEORESIN phenolic compounds
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A fast powerful X-ray transient from possible tidal disruption of a white dwarf
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作者 Dongyue Li Wenda Zhang +97 位作者 Jun Yang Jin-Hong Chen Weimin Yuan Huaqing Cheng Fan Xu Xinwen Shu Rong-Feng Shen Ning Jiang Jiazheng Zhu Chang Zhou Weihua Lei Hui Sun Chichuan Jin Lixin Dai Bing Zhang Yu-Han Yang Wenjie Zhang Hua Feng Bifang Liu Hongyan Zhou Haiwu Pan Mingjun Liu Stéphane Corbel Sitha KJagan Maria Cristina Baglio Christopher RBurns Floriane Cangemi Chun Chen Yehao Cheng Alexis Coleiro Francesco Coti Zelati Sourya RDas Zhongnan Dong Luis Galbany Noa Grollimund Daniel Kelson Dong Lai Xia Li Yuan Liu Alessio Marino Brenna Mockler Paul O'Brien Erlin Qiao Nanda Rea LResmi Jérome Rodriguez Richard Saxton Luming Sun Lian Tao Tinggui Wang Yilong Wang Xuefeng Wu Dong Xu Yijia Zhang Guoying Zhao Congying Bao Zhiming Cai Yehai Chen Yong Chen Bertrand Cordier Chenzhou Cui Weiwei Cui Zhou Fan He Gao Giancarlo Ghirlanda Ju Guan Dawei Han Jinxin Hao Jingwei Hu Maohai Huang Yong-Feng Huang Shumei Jia Ge Jin Stefanie Komossa Chengkui Li Zhixing Ling Congzhan Liu Heyang Liu Huaqiu Liu Fangjun Lu Kirpal Nandra Jan-Uwe Ness Arne Rau Jeremy Sanders Liming Song Roberto Soria Shengli Sun Xiaojin Sun Yuyin Tan Eleonora Troja Sixiang Wen Haitao Xu Changbin Xue Yongquan Xue Yi-Han Iris Yin Chen Zhang Shuang-Nan Zhang Yonghe Zhang 《Science Bulletin》 2026年第3期538-546,共9页
Stars getting close enough to black holes(BHs)can be torn apart by strong tidal forces,producing electromagnetic flares.To date,more than 100 tidal disruption events(TDEs)have been observed,each involving invariably n... Stars getting close enough to black holes(BHs)can be torn apart by strong tidal forces,producing electromagnetic flares.To date,more than 100 tidal disruption events(TDEs)have been observed,each involving invariably normal gaseous stars whose debris falls onto the BH,sustaining the flares over years.White dwarfs(WDs),which are the most prevalent compact stars and a million times denser-and therefore tougher-than gaseous stars,can only be disrupted by intermediate-mass black holes(IMBHs)of 10^(2)–10^(5) solar masses.WD-TDEs are considered to generate more powerful and short-lived flares,but their evidence has been lacking.Here we report observations of a fast and luminous X-ray transient EP250702a detected by Einstein Probe.Its one-day-long X-ray peak as luminous as 10^(47−49) erg s^(−1) showed strong recurrent flares with hard spectra extending to several tens of MeV gamma-rays,as detected by Fermi/GBM and Konus-Wind,indicating relativistic jet emission.The jet's X-rays dropped sharply from 3×10^(49) erg s^(−1) to around 1044 erg s^(−1) within 20 days(10 days in the source rest frame).These characteristics are inconsistent with any previously known transient phenomena.We suggest that this fast-evolving event over the unprecedentedly short timescale arises likely from disruption of a WD by an IMBH.At late times,a soft component progressively dominates the X-ray spectrum,reaching a luminosity as high as 1044 erg s^(−1),which is consistent with being extreme super-Eddington emission from an accretion disk expected to form in an IMBH-WD TDE.WD-TDEs open a new window for investigating the elusive IMBHs and their surrounding stellar environments,and they are prime sources of gravitational waves in the band of space-based interferometers. 展开更多
关键词 X-ray transient Intermediate-mass black hole Tidal disruption event White dwarf Tianguan Einstein Probe
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Method to Determine the Propulsion Characteristics of a Ship Moving in Ice 被引量:1
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作者 Kirill Sazonov Grigorii Kanevskii +1 位作者 Alexandr Klubnichkin Aleksei Dobrodeev 《哈尔滨工程大学学报(英文版)》 2025年第3期532-541,共10页
In designing modern vessels, calculating the propulsion performance of ships in ice is important, including propeller effective thrust, number of revolutions, consumed power, and ship speed. Such calculations allow fo... In designing modern vessels, calculating the propulsion performance of ships in ice is important, including propeller effective thrust, number of revolutions, consumed power, and ship speed. Such calculations allow for more accurate prediction of the ice performance of a designed ship and provide inputs for designers of ship power and automation systems. Preliminary calculations of ship propulsion and thrust characteristics in ice can enable predictions of full-scale ice resistance without measuring the propeller thrust during sea trials. Measuring propeller revolutions,ship speed, and the power delivered to propellers could be sufficient to determine the propeller thrust of the vessel. At present, significant difficulties arise in determining the thrust of icebreakers and ice-class ships in ice conditions. These challenges are related to the fact that the traditional system of propeller/hull interaction coefficients does not function correctly in ice conditions. The wake fraction becomes negative and tends to minus infinity starting from a certain value of the propeller advance coefficient. This issue prevents accurate determination of the performance characteristics, thrust, and rotational speed of the propulsors. In this study, an alternative system of propeller/hull interaction coefficients for ice is proposed. It enables the calculation of all propulsion parameters in ice based on standard hydrodynamic tests with selfpropulsion models. An experimental method is developed to determine alternative propeller/hull interaction coefficients. A prediction method is suggested to determine propulsion performance in ice based on the alternative interaction coefficient system. A case study applying the propulsion prediction method for ice conditions is provided. This study also discusses the following issues of ship operation in ice: the scale effect of icebreaker propellers and the prospects for introducing an ice interaction coefficient. 展开更多
关键词 ICEBREAKER Model experiment Interaction coefficients Propeller Calculation Off-design mode Propulsion characteristics Ship moving in ice
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Diagnosis of mitochondrial defects:livestock diseases
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作者 Boglárka Schilling-Tóth Dávid Kiss +4 位作者 Krisztián Németh Silvia Ondrašovičová Gergely Jócsák Tibor Bartha István Tóth 《Animal Diseases》 2025年第4期407-423,共17页
The energy centers of eukaryotic cells,known as mitochondria,are crucial for human and animal health and physiological functions.Mitochondria exhibit unique characteristics in multiple aspects,as they participate in e... The energy centers of eukaryotic cells,known as mitochondria,are crucial for human and animal health and physiological functions.Mitochondria exhibit unique characteristics in multiple aspects,as they participate in energy production and affect calcium homeostasis,proliferation,and programmed cell death.The mitochondria contain inner DNA that functions with nuclear DNA to influence regulatory processes and division.Moreover,this duality of DNA appears in the progression of mitochondrial disorders.These mitochondrial diseases,inherited or acquired,are a group of bioenergetic illnesses caused by mutations and alterations in crucial energy genes and functions.Many of these genetic changes increase during aging,leading to disorders connected to environmental stress.Mitochondrial diseases are a risk factor for domestic animals and can occur when a disorder develops due to heart,neurological,performance,or infertility problems.This review comprehensively analyzes diseases caused by inherited(primary)or environmental(secondary)damage to mtDNA and mitochondrial functions and their diagnostic possibilities in domestic animals.We will examine how to identify these issues,how they develop,and what we can do to provide our domestic animals with the best diagnostics. 展开更多
关键词 MITOCHONDRIAL DISEASES DOMESTIC ANIMALS DIAGNOSTICS Environmental stress
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An Aircraft Icing Detection Method Based on Performance Data of Rotor
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作者 WU Yuan ZHU Dongyu +1 位作者 XU Lingsong YU Lei 《Transactions of Nanjing University of Aeronautics and Astronautics》 2025年第2期212-225,共14页
Existing icing detection technologies face challenges when applied to small and medium-sized aircraft,especially electric vertical take-off and landing(eVTOL)aircraft that meet the needs of low-altitude economic devel... Existing icing detection technologies face challenges when applied to small and medium-sized aircraft,especially electric vertical take-off and landing(eVTOL)aircraft that meet the needs of low-altitude economic development.This study proposes a data-driven icing detection method based on rotor performance evolution.Through dry-air baseline tests and dynamic icing comparative experiments(wind speed 0—30 m/s,rotational speed 0—3000 r/min,collective pitch 0°—8°)of a 0.6 m rotor in the FL-61 icing wind tunnel,a multi-source heterogeneous dataset containing motion parameters,aerodynamic parameters,and icing state identifiers is constructed.An innovative signal processing architecture combining adaptive Kalman filtering and moving average cascading is adopted.And a comparative study is conducted on the performance of support vector machine(SVM),multilayer perceptron(MLP),and random forest(RF)algorithms,achieving real-time identification of icing states in rotating components.Experimental results demonstrate that the method exhibits a minimum detection latency of 6.9 s and 96%overall accuracy in reserved test cases,featuring low-latency and low false-alarm,providing a sensor-free lightweight solution for light/vertical takeoff and landing aircraft. 展开更多
关键词 ROTOR PROPELLER aircraft icing icing detection machine learning support vector machine(SVM) multilayer perceptron(MLP)
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Facial detection of formaldehyde by using acidichromic carbon dots and the reaction between formaldehyde and ammonium chloride
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作者 Quanxing Mao Zhengliang Wang +5 位作者 Zhinan Hu Ziqi Yang Hui Li Yali Yao Zijun Yong Tianyi Ma 《Chinese Chemical Letters》 2025年第7期262-265,共4页
Herein we report the facial detection of formaldehyde(FA)by using an interesting red acidichromic carbon dots(ACDs)which turns blue when pH gradually decreases.The color change was attributed to the conversion between... Herein we report the facial detection of formaldehyde(FA)by using an interesting red acidichromic carbon dots(ACDs)which turns blue when pH gradually decreases.The color change was attributed to the conversion between the double bonds(C=N)and single bonds(C-N)on the surface of the ACDs.Inspired by the reaction between FA and ammonium chloride that produces H^(+)and methenamine and decrease the pH value of the solution,a fast and simple visual detection method for FA was found with a minimum discriminated concentration of 0.04 mol/L.A fluorescence detection method for FA was also found with LOD of 0.029 mol/L and FA in real sample,e.g.,shredded squid was successfully analyzed.This work provides a new idea of developing fast visual detection method for daily monitor or in-site semiquantitative assessment on FA. 展开更多
关键词 Acidichromic feature Carbon dots FORMALDEHYDE Visual detection Indirect analysis
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Finger-Joint Lumber:A Systematic Literature Review and a Global Industry Survey on this Ecofriendly Structural Building Material
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作者 Victor De Araujo Pedro Jardim +5 位作者 Poliana Pessô Juliano Vasconcelos Matheus Souza José Garcia Jozef Švajlenka André Christoforo 《Journal of Renewable Materials》 2025年第12期2479-2524,共46页
Finger-joint lumber is a sustainable building product commercialized as a structural solution for beams,pillars and other thin flat load-bearing elements.This study aims to study finger-joint lumber and its industry t... Finger-joint lumber is a sustainable building product commercialized as a structural solution for beams,pillars and other thin flat load-bearing elements.This study aims to study finger-joint lumber and its industry to promote this engineered wood product.The first research stage assessed the collection of publications on fingerjoint lumber available globally,in which a structured protocol was developed to prospect studies based on two complementary methodologies:PRISMA 2020 using Scopus and Web of Science databases,and Snowball using both forward and backward models to complete with additional literature.The second research stage assessed finger-joint lumber manufacturers,in which companies were globally prospected using Google search engine and their corporate websites were profoundly analyzed using a structured script to collect information.Literary approaches have provided structural performance and bonding quality of finger-jointing.In the review,we provide a global overview and data regarding the current stage and future directions of finger-joint lumber for industrialized construction.Regarding this structural product,we review the main resources,material preparation and processing,and automated production.Mainly active in Europe and already present in 38 nations across five continents,we survey a finger-joint lumber industry comprising 186 producers controlling 214 manufacturing operations worldwide.The vast majority of this industry has exported linear engineered solutions in different dimensions,certified as to compliance with the origins of their bioresources and the European Union requirements,to markets exposed to 24 languages in order to meet commercial applications such as single-story houses,townhouses,roof structures,and hangars. 展开更多
关键词 Finger-jointed timber engineered wood product mass timber wood industry construction industry
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The Impact of Tropical Convective Heating on the Amundsen Sea Low in a Deep-Learning Weather Forecasting Model
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作者 Yibin HUANG Zhen-Qiang ZHOU +2 位作者 Renhe ZHANG Xiaohui ZHONG Hao LI 《Advances in Atmospheric Sciences》 2025年第12期2411-2421,共11页
Data-driven deep-learning models have shown outstanding performance in global weather forecasting.Understanding the dynamic response processes within these models is crucial for comprehending the embedded physical pro... Data-driven deep-learning models have shown outstanding performance in global weather forecasting.Understanding the dynamic response processes within these models is crucial for comprehending the embedded physical processes and sources of predictability.By applying the classic tropical steady heating experiment to the Pangu-Weather deep-learning model during the austral winter background state,we observe a classic Matsuno-Gill response in the tropics and planetary Rossby waves propagating to the polar regions.The results of the Pangu-Weather model are consistent with those of traditional physics-based general circulation models(GCMs):convective heating forcing in the tropical Atlantic and western Indian Ocean,and convective cooling forcing in the Maritime Continent all deepen the Amundsen Sea Low(ASL),while convective heating forcing in the western Pacific weakens the ASL.The Pangu-Weather model has learned that these tropical basins jointly and linearly regulate the atmospheric circulation around West Antarctica through Rossby waves.However,the Pangu-Weather model overestimates(underestimates)atmospheric responses of heating in the tropical Pacific(Indian and Atlantic)Ocean compared with traditional GCMs,with a much larger contribution of Pacific heating forcing than other basins in changes of the ASL.The physics learned from reanalysis data may be the source of these deep-learning models’predictability,and the accuracy of extended-range forecasting and the potential of seasonal forecasting using deep-learning models may be influenced by overestimation or underestimation of the role of the tropical Pacific,Indian,and Atlantic Oceans. 展开更多
关键词 deep learning Pangu-Weather Amundsen Sea Low Rossby wave austral winter
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Modulation of rice grain shape and appearance by the GS10-encoded long coiled-coil protein
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作者 Yanmin Luo Yuyu Chen +12 位作者 Pao Xue Beifang Wang Yiwei Kang Yue Zhang Daibo Chen Yongbo Hong Weixun Wu Qunen Liu Xiaodeng Zhan Yongjun Lin Shihua Cheng Yingxin Zhang Liyong Cao 《The Crop Journal》 2025年第1期158-169,共12页
Rice grain size is a primary characteristic essential for artificial domestication and breeding,governed by grain length,width,and thickness.In this study,we cloned Grain Size 10(GS10),a novel gene via mapbased clonin... Rice grain size is a primary characteristic essential for artificial domestication and breeding,governed by grain length,width,and thickness.In this study,we cloned Grain Size 10(GS10),a novel gene via mapbased cloning.Biochemical,molecular,and genetic studies were performed to elucidate the GS10 involved grain size mechanism in rice.Mutant of GS10 lead to reduced grain size due to alterations in cell expansion.Additionally,GS10 is responsible for the formation of notched-belly grains,especially in smaller grain varieties possessing loss-function mutations.Overexpression of GS10 in Nipponbare results in increasing grain length,grain weight and improve the appearance quality of rice.GS10 encodes conserved protein with uncharacterized function.Furthermore,GS10 regulates the grain size by interacting OsBRICK1,a subunit of the WAVE complex that governs actin nucleation and affects the assembly of microfilaments in rice.Together,our study demonstrates that,GS10 positively regulates the grain length and grain weight,which is beneficial for further improvements in yield characteristics. 展开更多
关键词 GS10 Grain size Grain weight Appearance quality MICROFILAMENTS
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祁连山区黑河上游多年冻土分布考察 被引量:30
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作者 王庆峰 张廷军 +6 位作者 吴吉春 彭小清 钟歆玥 牟翠翠 王康 吴青柏 程国栋 《冰川冻土》 CSCD 北大核心 2013年第1期19-29,共11页
高山多年冻土的分布及土壤季节冻融过程对地表水文过程、生态系统、碳循环及寒区工程建设等都有很大的影响.黑河上游地处祁连山中东部,属于高原亚寒带半干旱气候,研究黑河流域多年冻土分布对于系统理解该区域的生态-水文过程、气候与环... 高山多年冻土的分布及土壤季节冻融过程对地表水文过程、生态系统、碳循环及寒区工程建设等都有很大的影响.黑河上游地处祁连山中东部,属于高原亚寒带半干旱气候,研究黑河流域多年冻土分布对于系统理解该区域的生态-水文过程、气候与环境变化以及水资源评价、工程建设等非常重要.2011年6—8月对黑河干流源头西支开展了多年冻土调查,沿二尕公路(S204)在热水大坂垭口至石棉矿岔口之间区域,完成测温孔7眼,并布设测温管进行地温监测.根据勘察、钻探及测温资料,确定了黑河源头地区山地多年冻土下界为海拔3 650~3 700m之间.受高度地带性的控制,随着海拔的降低,活动层厚度由在海拔4 132m时的1.6m增加至在多年冻土下界处的约4.0m,多年冻土年平均地温也相应的由-1.7℃增加到0.0℃左右,而多年冻土厚度由100m以上减小到多年冻土下界处的0.0m.同时,坡度和坡向、岩性、含水(冰)量、地下水、河水等局地因素对多年冻土温度和厚度也有重要的作用. 展开更多
关键词 多年冻土下界 活动层 海拔 年平均地温 黑河流域
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祁连山区黑河上游俄博岭多年冻土区活动层碳储量研究 被引量:21
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作者 牟翠翠 张廷军 +3 位作者 曹斌 万旭东 彭小清 程国栋 《冰川冻土》 CSCD 北大核心 2013年第1期1-9,共9页
为了探索在全球气候变化背景下多年冻土区碳储量现状,通过野外实地勘探和室内实验,对黑河上游俄博岭多年冻土区地貌特征及不同海拔活动层内的碳储量进行考察和估算.结果表明:黑河上游俄博岭冰缘现象显著,土壤季节冻融过程活跃,且活动层... 为了探索在全球气候变化背景下多年冻土区碳储量现状,通过野外实地勘探和室内实验,对黑河上游俄博岭多年冻土区地貌特征及不同海拔活动层内的碳储量进行考察和估算.结果表明:黑河上游俄博岭冰缘现象显著,土壤季节冻融过程活跃,且活动层中碳储量丰富.在研究区约2.5×106 m2的范围内,活动层平均厚度约为1.1m,活动层土壤有机质平均含量约为72.1%,碳储量估算约为1.57Mt C.活动层不同深度处有机质含量呈现不同的变化规律.随着活动层深度增加,土壤有机质的含量逐渐降低,在多年冻土上限附近有机质含量较高.另外,活动层有机质含量随着海拔和土壤含水量的不同而变化,同时多年冻土区微地形和地质条件也对有机质含量具有重要的影响. 展开更多
关键词 活动层 气候变暖 有机质含量 碳储量估算
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欧亚大陆积雪分布及其类型划分 被引量:46
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作者 张廷军 钟歆玥 《冰川冻土》 CSCD 北大核心 2014年第3期481-490,共10页
利用1966-2012年欧亚大陆1 152个地面气象台站积雪深度资料,对欧亚大陆积雪深度、累计积雪天数和连续积雪天数的空间分布进行了分析,以连续积雪天数为标准对欧亚大陆季节性积雪类型进行了划分,并与应用累计积雪天数对积雪区类型的划分... 利用1966-2012年欧亚大陆1 152个地面气象台站积雪深度资料,对欧亚大陆积雪深度、累计积雪天数和连续积雪天数的空间分布进行了分析,以连续积雪天数为标准对欧亚大陆季节性积雪类型进行了划分,并与应用累计积雪天数对积雪区类型的划分进行了比较研究.结果表明:欧亚大陆积雪分布具有显著纬度地带性特征,积雪深度、累计积雪天数和连续积雪天数的大值分布区均位于俄罗斯平原的东北部、科拉半岛、西西伯利亚平原、中西伯利亚高原以及俄罗斯远东北部大部分区域.与累计积雪天数划分方法相比,利用连续积雪天数对欧亚大陆季节性积雪分区,在前苏联地区积雪类型分区差异并不显著,但蒙古和中国的稳定积雪区明显缩减,青藏高原无稳定积雪区,中国大部分地区为非周期性不稳定积雪区.两种积雪分区划分方法比较结果显示,连续积雪天数划分方法更能体现积雪累积的连续性和持久性,更符合对稳定积雪和不稳定积雪的划分标准. 展开更多
关键词 积雪深度 积雪天数 积雪类型 欧亚大陆
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基于准则分析的工程伦理教育探讨 被引量:6
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作者 张满 王孙禺 《高等工程教育研究》 CSSCI 北大核心 2017年第4期68-72,共5页
本文基于对高校教师与工程师样本群体的调查与实证研究,建构了工程伦理准则的体系,分析了两个不同群体的认同差异。通过探索性因子分析发现,工程伦理准则体系由"工作精神"、"品行特征"、"工作宗旨"和&qu... 本文基于对高校教师与工程师样本群体的调查与实证研究,建构了工程伦理准则的体系,分析了两个不同群体的认同差异。通过探索性因子分析发现,工程伦理准则体系由"工作精神"、"品行特征"、"工作宗旨"和"责任品质"四个维度构成;通过独立样本检验的差异分析和重要性排序结果的分析发现,高校伦理教育者与工程师两个群体在工程伦理准则内容选择方面存在明显差异。作者基于工程伦理准则体系的实证结果、高校教师与工程师本身对于工程伦理准则体系认同的差异性,提出了改进中国工程伦理教育的相关建议。 展开更多
关键词 工程伦理教育 工程伦理准则 教育改革 人才培养与开发
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中国1956—2006年地表土壤冻结天数时空分布及其变化特征 被引量:13
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作者 王康 张廷军 《地球科学进展》 CAS CSCD 北大核心 2013年第11期1269-1275,共7页
应用中国境内845个气象台站的地表日最低温度资料,计算分析了近地表土壤冻结天数在1971—2000年的气候平均值;探讨了其空间的分布特征及其与冻土分布的关系;构建并分析了1956—2006年地表土壤冻结天数的时间序列及其与气侯变化的关系。... 应用中国境内845个气象台站的地表日最低温度资料,计算分析了近地表土壤冻结天数在1971—2000年的气候平均值;探讨了其空间的分布特征及其与冻土分布的关系;构建并分析了1956—2006年地表土壤冻结天数的时间序列及其与气侯变化的关系。结果表明,中国境内近地表土壤冻结天数的气候平均值随纬度增加、海拔升高而增加。青藏高原、新疆北部和东北地区北部多年平均冻结天数均超过200天。多年冻土区的边界与冻结天数(220±10)天的等值线高度吻合。按冻结天数大于15天为季节冻土区的定义,中国季节冻土的最南界约为25°N,22°N以南地区基本为非冻结区。自1956年以来,中国境内近地表土壤冻结天数呈显著的下降趋势,变化速率为-0.22 d/a,但20世纪90年代以后,其减少速率可达-1.02 d/a。近地表土壤冻结天数的变化与气温变化呈负相关关系,即随气温升高近地表土壤冻结天数减少。 展开更多
关键词 土壤表面 冻结天数 气候变化 地表温度 冻土
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我国冰冻圈及其变化的脆弱性与评估方法 被引量:15
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作者 杨建平 张廷军 《冰川冻土》 CSCD 北大核心 2010年第6期1084-1096,共13页
基于脆弱性研究文献,从脆弱性概念、评估内容、评估方法等方面系统总结了脆弱性评估研究的特点和趋势,开展脆弱性评估时应注意的系统、关注特征、灾害、尺度与时间等五个方面,剖析了区域尺度脆弱性评估涉及的一系列问题,介绍了脆弱性评... 基于脆弱性研究文献,从脆弱性概念、评估内容、评估方法等方面系统总结了脆弱性评估研究的特点和趋势,开展脆弱性评估时应注意的系统、关注特征、灾害、尺度与时间等五个方面,剖析了区域尺度脆弱性评估涉及的一系列问题,介绍了脆弱性评估方法及其优缺点和适用性.探讨了我国冰冻圈及其变化的脆弱性概念,分析了二者之间的关系,论述了我国冰冻圈及其变化的脆弱性评估内容、评估尺度和评估方法. 展开更多
关键词 脆弱性 冰冻圈的脆弱性 冰冻圈变化的脆弱性 脆弱性评估方法
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中国寒区水文学研究的新阶段——记我国杰出寒区水文学家叶柏生研究员的创新与贡献 被引量:7
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作者 丁永建 刘时银 +6 位作者 刘凤景 杨大庆 张廷军 赵林 沈永平 阳坤 张世强 《冰川冻土》 CSCD 北大核心 2012年第5期1009-1022,共14页
我国杰出的寒区水文学家叶柏生研究员不幸因公殉职.选取了叶柏生研究员若干代表性研究成果,包括与他人的合作研究成果,重点从冰川水文、冻土水文和区域水文变化三方面总结了其对寒区水文学发展所做的创新与贡献.文章列出了每项研究成果... 我国杰出的寒区水文学家叶柏生研究员不幸因公殉职.选取了叶柏生研究员若干代表性研究成果,包括与他人的合作研究成果,重点从冰川水文、冻土水文和区域水文变化三方面总结了其对寒区水文学发展所做的创新与贡献.文章列出了每项研究成果的核心内容,并给予了简要评述.所选成果中,冰川水文方面研究涉及冰川对河川径流的调节作用、冰川径流对气候变化的响应机理等;冻土水文研究着重介绍了多年冻土变化对流域径流过程及其变化影响方面的系统性成果;区域水文变化研究方面,选取了降水观测误差修正、气候变化对区域径流的影响等方面的创新成果.这些研究成果极大地提高了我国在世界寒区水文学研究的地位,对认识寒区水文过程及气候变化对水资源的影响具有重要科学意义. 展开更多
关键词 冰川水文 冻土水文 区域水文变化 气候变化 创新与贡献 叶柏生研究员
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引领工程教育创新发展 培养一流工程科技人才 被引量:16
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作者 张满 乔伟峰 王孙禺 《高等工程教育研究》 CSSCI 北大核心 2019年第2期117-123,共7页
2018年9月24~25日,清华大学、中国工程院和联合国教科文组织共同举办了第一届国际工程教育论坛。论坛围绕全球化背景下工程教育面临的机遇与挑战、工程教育的实践与探索、一流工科建设、工程教育的创新发展、工程教育的可持续发展等问... 2018年9月24~25日,清华大学、中国工程院和联合国教科文组织共同举办了第一届国际工程教育论坛。论坛围绕全球化背景下工程教育面临的机遇与挑战、工程教育的实践与探索、一流工科建设、工程教育的创新发展、工程教育的可持续发展等问题进行了交流和讨论,来自全球不同领域的专家提出了各自的见解。近200位代表参加了本次论坛,论坛上共有来自中国、美国、德国、日本、英国、瑞典、加拿大、新加坡等国的68位知名大学校长、专家学者、研究机构和企业代表进行了发言。本文基于这些发言从工程教育面临的主要挑战、工程教育的创新实践和未来工程人才培养与工程教育发展趋势三个方面提出了相关观点。 展开更多
关键词 工程教育 创新发展 一流工科建设 可持续发展
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Association between hepatitis B and metabolic syndrome:Current state of the art 被引量:9
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作者 Peter Jarcuska Sylvia Drazilova +2 位作者 Jan Fedacko Daniel Pella Martin Janicko 《World Journal of Gastroenterology》 SCIE CAS 2016年第1期155-164,共10页
Chronic hepatitis B(CHB)is a global health issue that increases the risk of liver cirrhosis and hepatocellular carcinoma in infected patients.Metabolic syndrome(Met S)is a disease endemic mostly to the developed count... Chronic hepatitis B(CHB)is a global health issue that increases the risk of liver cirrhosis and hepatocellular carcinoma in infected patients.Metabolic syndrome(Met S)is a disease endemic mostly to the developed countries.It is associated with high cardiovascular mortality and morbidity,diabetes mellitus as well as cancer.In this manuscript,we systematically review the published data on the relationship between Met S and CHB infection.Multiple studies have described highly variable correlations between CHB on one hand and Met S,non-alcoholic fatty liver disease and dyslipidemia on the other.No association between CHB and diabetes mellitus or atherosclerosis has been described as of now.The presence of Met S in patients infected with hepatitis B virus increases the risk of fibrosis,cirrhosis and hepatocellular carcinoma.Appropriate lifestyle,but also pharmacological interventions are needed to prevent the development of these complications. 展开更多
关键词 HEPATITIS B NONALCOHOLIC FATTY liver disease FIBROSIS CIRRHOSIS Metabolic syndrome Hepatocellularcarcinoma
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Neuroprotective agents effective against radiation damage of central nervous system 被引量:5
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作者 Mária Lalkovičová 《Neural Regeneration Research》 SCIE CAS CSCD 2022年第9期1885-1892,共8页
Ionizing radiation caused by medical treatments,nuclear events or even space flights can irreversibly damage structure and function of brain cells.That can result in serious brain damage,with memory and behavior disor... Ionizing radiation caused by medical treatments,nuclear events or even space flights can irreversibly damage structure and function of brain cells.That can result in serious brain damage,with memory and behavior disorders,or even fatal oncologic or neurodegenerative illnesses.Currently used treatments and drugs are mostly targeting biochemical processes of cell apoptosis,radiation toxicity,neuroinflammation,and conditions such as cognitive-behavioral disturbances or others that result from the radiation insult.With most drugs,the side effects and potential toxicity are also to be considered.Therefore,many agents have not been approved for clinical use yet.In this review,we focus on the latest and most effective agents that have been used in animal and also in the human research,and clinical treatments.They could have the potential therapeutical use in cases of radiation damage of central nervous system,and also in prevention considering their radioprotecting effect of nervous tissue. 展开更多
关键词 antioxidants biomedical neuroprotectants central nervous system ionizing radiation NEUROPROTECTION radiation injury radiomitigators radioprotectants RADIOPROTECTION THERAPEUTICS
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