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Investigation of the medium calcium based non-burnt brick made by red mud and fly ash: durability and hydration characteristics 被引量:14
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作者 Ying-tang Xu Bo Yang +4 位作者 Xiao-ming Liu Shuai Gao Dong-sheng Li Emile Mukiza Hua-jian Li 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2019年第8期983-991,共9页
Red mud is a type of highly alkaline waste residue produced in the process of alumina smelting by the Bayer process.Based on the idea of medium calcium content,solid wastes such as red mud and fly ash were used to pre... Red mud is a type of highly alkaline waste residue produced in the process of alumina smelting by the Bayer process.Based on the idea of medium calcium content,solid wastes such as red mud and fly ash were used to prepare non-burnt bricks;and the mass ratio of CaO/SiO2 was selected in the range of 0.88–1.42.Mechanical properties and durability were investigated with a compressive strength test.X-ray diffractometry(XRD),scanning electron microscope(SEM),and Fourier transform infrared spectroscopy(FTIR)techniques were used to characterize the hydration characteristic.The environmental performance was analyzed by Inductively Coupled Plasma Mass Spectrometry(ICP).The results indicated that the mechanical properties and the durability were optimal when the mass ratio of CaO/SiO2 was 1.23.The hydration products were mostly C–S–H gel,ettringite,Na4Ca(Si10All6)O32·12H2O and Ca3Al2(SiO4)(OH)8.They were responsible for the strength development,and the CaO/SiO2 mass ratio of 1.23 had the best polymerized structure.The results of an environmental performance test showed that the heavy metals in the raw materials were well-solidified in the brick.Therefore,this paper provides an effective solution for use of solid wastes in building material. 展开更多
关键词 MEDIUM CALCIUM content red MUD fly ash non-burnt BRICK
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Preparation and Metallurgical Analysis of High Activity Burnt Lime for Steelmaking 被引量:2
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作者 Hua-qiang HAO Yu-zhu ZHANG +3 位作者 Su-ju HAO Chao-fa ZHANG Wu-feng JIANG Peng-hui CUI 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2016年第9期884-890,共7页
Burnt lime is an important material in steelmaking and its activity degree is a key factor for liquid steel quality. The burnt lime was made by the calcination of limestone in a high pressure electric furnace. The bur... Burnt lime is an important material in steelmaking and its activity degree is a key factor for liquid steel quality. The burnt lime was made by the calcination of limestone in a high pressure electric furnace. The burnt lime mineralogical phases and micro-morphologies were characterized by X-ray diffraction (XRD) and field emission scan- ning electron microscopy (FE-SEM). The burnt lime activity degree was determined by acid-base titration, the burnt lime pore distribution was measured by mercury intrusion porosimetry (MIP), and the thermal effect of a mixture of burnt lime and slag was measured by differential scanning calorimetry (DSC). The results showed that the CaO grain size and pore size of burnt lime made under high pressure were larger than those of burnt lime made under atmos- pheric pressure. The CaO grain size and pore size increased and the laminate phenomenon also occurred clearly under high pressure. The activity degree of burnt lime made under high pressure was greater than that made under atmos- pheric pressure. The maximum activity degree was 437 mL for burnt lime made under a pressure of 0.4 MPa. For the same ratio of CaO to SiOz, the melting temperature, hemisphere temperature and fluidity temperature of slag decreased with increasing burnt lime activity degree. The higher the activity degree the burnt lime had, the better the slag forming occurred. It was advantageous for -2CaO · SiO2 and 3CaO · SiO2 forming at lower temperatures if the burnt lime activity degree was increased. 展开更多
关键词 burnt lime high pressure calcination activity degree physical property slag performance
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Sensitive Evaluation on Early Cracking Tendency of Concrete with Inclusion of Light-burnt MgO 被引量:4
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作者 陈霞 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2011年第5期1018-1022,共5页
The advanced temperature and stress test machine was introduced to determine the early cracking tendency of concrete with inclusion of light-burnt MgO under full restraint by tracking the development of thermal,physic... The advanced temperature and stress test machine was introduced to determine the early cracking tendency of concrete with inclusion of light-burnt MgO under full restraint by tracking the development of thermal,physical and deformation properties.Results showed that light-burnt MgO being incorporated ranging between 4 wt% and 6 wt% of cementitious materials was beneficial to increase the maximum compressive stress and cracking stress of concrete by 0.37 MPa and 0.2 MPa on average respectively.The second zero stress temperature was reduced by 11.4 ℃ and the maximum temperature was slightly reduced while cracking thermal impact was significantly enhanced from 59.8 ℃ to 66.2 ℃.Sensitive anti-cracking coefficient F was forwarded to assess the early cracking tendency of concrete and the inclusion of 4 wt% light-burnt MgO with activity of 109 s ranked the best in crack resistance. 展开更多
关键词 crack resistance cracking stress light-burnt MgO CONCRETE sensitive evaluation
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An improved algorithm for mapping burnt areas in the Mediterranean forest landscape of Morocco 被引量:1
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作者 Issameddine Zidane Rachid Lhissou +1 位作者 Abdelali Bouli Mustapha Mabrouki 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第3期981-992,共12页
The identification of burnt forests and their monitoring provide essential information for the suitable management and conservation of these ecosystems. This research focuses on the use of remote sensing with MODIS se... The identification of burnt forests and their monitoring provide essential information for the suitable management and conservation of these ecosystems. This research focuses on the use of remote sensing with MODIS sensor data in a Mediterranean environment, precisely in the Rif region known for its high occurrence of forest fires and the largest burnt areas in Morocco. It mapped the burnt areas during the summer of 2016 using spectral indices from MODIS images, namely the Normalized Burn Ratio (NBR) and the Burnt Area Index for MODIS (BAIM). Two field surveys were used to calibrate spectral indices and validate the maps. First, a monotemporal analysis using a single pre-fire image determined the appropriate threshold of the spectral indices (BAIM and NBR) for burn detecting. Secondly, a multitemporal method was applied based on dBAIM and dNBR images which represented pre-fire and postfire differences of the BAIM and NBR images, respectively. The results show that separate use of monotemporal postfire and multitemporal methods produced an overestimation of the burnt areas. Finally, we propose a new algorithm combining both methods for burnt area mapping that we name Burnt Area Algorithm. MCD45A1 and MCD64A1 MODIS burnt area products were compared to the proposed algorithm. Validation of the estimated burnt areas using reference data of the Moroccan High Commission for Water, Forests and Fight against Desertification showed satisfactory results using the proposed algorithm, with a determination coefficient of 0.68 and a root mean square error of 44.0 ha. 展开更多
关键词 burnt FOREST MAPPING THRESHOLD MODIS MCD45A1 MCD64A1 SPECTRAL indices Morocco
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Petrologic and REE Geochemical Characters of Burnt Rocks 被引量:1
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作者 HUANG Lei LIU Chiyang YANG Lei ZHAO Junfeng FANG Jianjun 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2008年第2期392-398,共7页
The study of burnt rocks is beneficial to the discussion on the tectonic movement, paleoclimate and paleogeography that coal seams are subjected to after they were formed. In order to obtain the basic data on the feat... The study of burnt rocks is beneficial to the discussion on the tectonic movement, paleoclimate and paleogeography that coal seams are subjected to after they were formed. In order to obtain the basic data on the features of the burnt rocks, a systematic study of petrology and REE geochemistry on burnt rocks in Shenmu, Northern Shaanxi Province has been done, using the methods of SEM, EDS, susceptibility measurements and ICP-MS. The burnt rocks are divided into two series in the section: the melted rocks and the baked rocks. SEM and EDS analyses reveal that all the minerals show burnt and melted traces, and there are no clay minerals except illite found in the burnt rocks. Susceptibility measurements reveal that the burnt rocks have abnormally high susceptibility values, whereas a geochemical analysis shows that the REE distribution pattern of burnt rocks is similar to that of sedimentary rocks (initial rocks). In the longitudinal section, with increasing degree of burning (from baked rocks to melted rocks), the ∑REE gradually decreases, and the total REE of melted rocks is obviously lower than that of baked rocks. Besides, the melted rocks show apparent negative Ce anomalies, while the baked rocks show no anomaly of Ce, and sometimes even show positive anomalies. 展开更多
关键词 burnt rock mineral petrology SUSCEPTIBILITY REE negative Ce anomaly
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Temperature field distribution of burnt surrounding rock in UCG stope 被引量:10
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作者 Xin Lin Wang Zuotang +4 位作者 Huang Wengang Kang Guojun Lu Xuefeng Zhang Peng Wang Jianhua 《International Journal of Mining Science and Technology》 SCIE EI 2014年第4期573-580,共8页
In order to study temperature field distribution in burnt surrounding rock and to determine ranges of burnt surrounding rock, coal-wall coking cycle and heat influence in the underground coal gasification(UCG) stope, ... In order to study temperature field distribution in burnt surrounding rock and to determine ranges of burnt surrounding rock, coal-wall coking cycle and heat influence in the underground coal gasification(UCG) stope, based on the Laplace transform and inversion formula, we studied the temperature analytical solution of one-dimensional unsteady heat conduction for multi-layer overlying strata under the first and the forth kinds of boundary conditions, and we also carried out a numerical simulation of twodimensional unsteady heat conduction by the COMSOL multiphysics. The results show that when the boundary temperature of surrounding rock has a linear decrease because of a directional movement of heat source in the UCG flame working face, the temperature in surrounding rock increases first and then decreases with time, the peak of temperature curve decreases gradually and its position moves inside surrounding rock from the boundary. In the surrounding rock of UCG stope, there is an envelope curve of temperature curve clusters. We analyzed the influence of thermophysical parameters on envelope curves and put forward to take envelope curve as the calculation basis for ranges of burnt surrounding rock, coal-wall coking cycle and heat influence. Finally, the concrete numerical values are given by determining those judgement standards and temperature thresholds, which basically tally with the field geophysical prospecting results. 展开更多
关键词 Underground coal gasification (UCG) Temperature distribution Laplace transform Envelope curve burnt surrounding rock Coking cycle
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Forest structure, diversity and regeneration in unburnt and burnt Anogeissus latifolia forests in Garhwal Himalayas
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作者 Munesh KUMAR Jahangeer A. BHAT G. S. RAJWAR 《Forestry Studies in China》 CAS 2012年第4期268-275,共8页
The present study was carried out at two different gradients of unbumt and burnt Anogeissus latifolia forest sites in the Garhwal region, India. At each gradient, the unburnt and burnt forest sites were further catego... The present study was carried out at two different gradients of unbumt and burnt Anogeissus latifolia forest sites in the Garhwal region, India. At each gradient, the unburnt and burnt forest sites were further categorized into three different elevations, i.e., lower (700 m), middle (850 m) and upper (1000 m). At each elevation, the density of trees, saplings and seedlings was higher at the unburnt sites except for trees at the upper elevation which was higher at the burnt sites. The total basal area of each layer of for- est was also higher at the unburnt sites. The study revealed that the lower number of saplings and seedlings at the burnt forest sites might be due to the effect of fire. Most trees in the lower dbh classes were affected by forest fire at the burnt sites which reduced the total density and total basal area of the trees compared to the unburnt sites. The diversity of trees increased with increasing elevation. However, the diversity of saplings and seedlings reduced with increasing elevation. 展开更多
关键词 Anogeissus latifolia unburnt and burnt forest elevational gradient DIVERSITY REGENERATION
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Adult with mass burnt lime aspiration: A case report and literature review
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作者 Xin-Yu Li Hai-Jia Hou +2 位作者 Bing Dai Wei Tan Hong-Wen Zhao 《World Journal of Clinical Cases》 SCIE 2021年第32期9935-9941,共7页
BACKGROUND Foreign body aspiration mainly occurs in children,which can cause a severe concurrent syndrome and even death without timely treatment.As a rare foreign body,aspiration of lime is seldom reported,and most c... BACKGROUND Foreign body aspiration mainly occurs in children,which can cause a severe concurrent syndrome and even death without timely treatment.As a rare foreign body,aspiration of lime is seldom reported,and most cases involve a small amount of hydrated lime.Although the symptoms are usually severe,the prognosis is good after suitable treatment.Experience of treatment for lime aspiration is lacking,and this report provides novel evidence for treatment of mass burnt lime aspiration using bronchoscopy.CASE SUMMARY We report an adult with a large amount of burnt lime aspiration.Because of delay in clearance of the inhaled lime in the trachea and bronchus at the local hospital,he suffered several severe complications,including complete occlusion of the right primary bronchus,aeropleura,aerodermectasia,pneumomediastinum,secondary infection and hypoxemia at 4 d after injury.After transferring to our department,bronchoscopy was immediately carried out to clear the lime in the major airway,using foreign body forceps,biopsy forceps,puncture needle,and hairbrush.The patient’s condition recovered rapidly and at 3-months’follow-up,he demonstrated good recovery of the bronchus and lung parenchyma.CONCLUSION After mass lime aspiration,flexible fiberoptic bronchoscopy is suggested as early as possible,using clamping,flushing or cryotherapy. 展开更多
关键词 burnt lime ASPIRATION Bronchial obstruction Flexible fiberoptic bronchoscopy Computed tomography Case report
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Distributions of rare-earth elements in two Chinese coals and their burnt products
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作者 姚多喜 支霞臣 《Journal of Coal Science & Engineering(China)》 2005年第2期71-74,共4页
The concentrations of two fresh Chinese coals (lignitie and fatty coal ) from dif-ferent geological origin and the corresponding fly and bottom ashes were determined us-ing inductively coupled plasma mass spectrometry... The concentrations of two fresh Chinese coals (lignitie and fatty coal ) from dif-ferent geological origin and the corresponding fly and bottom ashes were determined us-ing inductively coupled plasma mass spectrometry(ICP-MS). The ranges and means of concentrations of these elemennts were given. Based on the combustion simulating ex-periment in the one-dismensional boiler, the contents of REE (rare-earth element) of 18 samples in lignite, fatty coal and their fly and bottom ashes in different combustion condi-tion were determined, and geochemical feature of REE were analyzed. 展开更多
关键词 REE DISTRIBUTION burnt products coal combustion two Chinese coals
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“Burnt-Out” Endomyocardial Fibrosis—An Overview
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作者 Ramachandran Muthiah 《Case Reports in Clinical Medicine》 2016年第11期437-493,共57页
Tropical endomyocardial fibrosis (EMF) is a public health problem affecting the children, young adults and elderly individuals in an epidemic fashion in the coastal districts of south India. Due to lack of resources f... Tropical endomyocardial fibrosis (EMF) is a public health problem affecting the children, young adults and elderly individuals in an epidemic fashion in the coastal districts of south India. Due to lack of resources for research in these endemic areas, its etiology remains elusive and hypotheses ranging from infections and allergic causes to malnutrition and toxins have not been tested rigorously. The disease is characterized by endocardial fibrosis and the right ventricle is the cardiac chamber most frequently affected. Patients may present clinically with heart failure and an associated AV (atrioventricular) valve regurgitation is common. Several features of the advanced disease called as “burnt-out” stage of endomyocardial fibrosis (EMF) are not fully understood. Background of these case studies described the clinical presentation, echocardiographic features and management of this late stage of the disease. 展开更多
关键词 Endomyocardial Fibrosis burnt-Out Stage Pericardial Effusion Endocardial Calcification “Cobra-Head” Fibrosis
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燃煤渣对水泥力学和水化过程的影响
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作者 刘仕琪 周紫晨 +4 位作者 黄修林 曾明 张冰 张剑峰 沈春华 《硅酸盐通报》 北大核心 2026年第1期165-176,共12页
水化活性较低是限制燃煤渣作为辅助胶凝材料应用的关键因素,本文通过机械球磨方式激发燃煤渣水化活性,并系统研究了燃煤渣活性提升机理及对复合胶凝材料力学性能和水化过程的影响。结果表明:机械球磨破坏了燃煤渣中层状硅铝酸盐结构,引... 水化活性较低是限制燃煤渣作为辅助胶凝材料应用的关键因素,本文通过机械球磨方式激发燃煤渣水化活性,并系统研究了燃煤渣活性提升机理及对复合胶凝材料力学性能和水化过程的影响。结果表明:机械球磨破坏了燃煤渣中层状硅铝酸盐结构,引起Si—O、Al—O结合能变化;与燃煤渣相比,球磨燃煤渣活性硅铝的浓度分别提升694.55%和634.27%。当球磨燃煤渣掺量为30%(质量分数)时,复合胶凝材料3和28 d的抗压强度相比基准组分别提升6.03%和22.38%,相比对照组分别提升49.13%和82.99%。球磨燃煤渣的掺入能够促进Ca(OH)_(2)的消耗,增加水化硅酸钙(C-S-H)凝胶等水化产物的含量,增强微观结构致密性,提升复合胶凝材料力学性能。在不影响复合胶凝材料力学性能情况下,材料的累计水化放热量随燃煤渣掺量增加逐渐降低。 展开更多
关键词 球磨燃煤渣 活性硅铝 辅助胶凝材料 晶体结构 力学性能 水化机理
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Disaster victim identification operations with fragmented,burnt,or commingled remains:experience-based recommendations 被引量:3
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作者 Hans H.de Boer Julie Roberts +2 位作者 Tania Delabarde Amy Z.Mundorff Soren Blau 《Forensic Sciences Research》 CSCD 2020年第3期191-201,共11页
Human-made and natural disasters can result in severely fragmented,compromised,and commingled human remains.The related disaster victim identification(DVI)operations are invariably challenging,with the state of the re... Human-made and natural disasters can result in severely fragmented,compromised,and commingled human remains.The related disaster victim identification(DVI)operations are invariably challenging,with the state of the remains potentially precluding some identifications.Practitioners involved in these DVI operations will routinely face logistical,practical,and ethical challenges.This review provides information and guidance derived from firsthand experiences to individuals tasked with managing DVI operations with fragmented human remains.We outline several key issues that should be addressed during disaster preparedness planning and at the outset of an operation,when incident-specific strategies are developed.Specific challenges during recovery and examination of fragmented remains are addressed,highlighting the importance of experienced specialists at the scene and in the mortuary.DNA sample selection and sampling techniques are reviewed,as well as downstream effects of commingling and contamination,which can complicate reconciliation and emphasise the need for rigorous quality control.We also touch on issues that may arise during communication with families.While recommendations are provided,they are not intended as proscriptive policy but rather as an addition to the general recommendations given in the International Criminal Police Organization(INTERPOL)DVI Guide,to inform preparative discussions between government officials,judiciary,police,and forensic specialists. 展开更多
关键词 Forensic sciences forensic anthropology DVI fragmented human remains burnt commingled DNA
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太原市国有林场火烧迹地植被自然更新与恢复调查研究
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作者 杜明江 《森林防火》 2026年第1期61-64,共4页
围绕太原市国有林场火烧迹地植被自然更新与恢复主题,对火烧迹地植被自然更新与恢复进行跟踪调查,并对观测结果进行分析总结,针对分析结论提出植被恢复建议,力求为太原市国有林场火烧迹地植被更新与恢复研究奠定一定的基础。
关键词 火烧迹地 自然更新 合理干预 生态系统 管理策略
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浅埋煤层烧变岩边界连续探查技术研究
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作者 薛小渊 白阳 +1 位作者 姬中奎 郭森林 《中国煤炭地质》 2026年第1期47-51,58,共6页
针对传统的浅埋煤层烧变岩边界探查不连续、精度较低的问题,提出了以磁法结果为依据,首次引进地面水平定向钻技术对烧变岩边界进行连续探查。以陕北南梁煤矿3^(-1)煤烧变岩边界探查为例,应用磁法和地面定向钻技术对3^(-1)煤烧变岩边界... 针对传统的浅埋煤层烧变岩边界探查不连续、精度较低的问题,提出了以磁法结果为依据,首次引进地面水平定向钻技术对烧变岩边界进行连续探查。以陕北南梁煤矿3^(-1)煤烧变岩边界探查为例,应用磁法和地面定向钻技术对3^(-1)煤烧变岩边界和实煤体进行了连续探查,地面定向钻钻进过程中结合岩屑录井、冲洗液观测、钻压数据观测、钻孔电视等技术手段,可实时对烧变岩、煤层、异常区进行辨识,结果表明,利用水平定向钻技术可一次大范围对烧变岩边界进行连续探查,提高烧变岩边界控制精度,为工作面布置提供合理依据,推广前景和经济效益较大,可为类似条件下复杂边界探查提供新的思路和探查手段。 展开更多
关键词 浅埋煤层 烧变岩 边界探查 地面定向钻探
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Burnt Rubber
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作者 LIU XINLIAN 《Beijing Review》 2011年第49期32-33,共2页
Driving away Chinese tires has not benefited the U.S. tire industry, but has harmed their trade ties Two years after imposing punitive tariffs on Chinese-manufactured passenger vehicle and truck tires, the United Stat... Driving away Chinese tires has not benefited the U.S. tire industry, but has harmed their trade ties Two years after imposing punitive tariffs on Chinese-manufactured passenger vehicle and truck tires, the United States may launch a new round against truck and bus tires imported from China, reported 21st Century Business Herald based in Guangzhou, capital of Guangdong Province. 展开更多
关键词 WTO burnt Rubber
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采煤工作面上覆煤层烧变岩富水性的探测技术应用研究
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作者 代凤强 《价值工程》 2026年第4期91-94,共4页
陕北重要煤炭基地广泛分布着因煤层自燃形成的火烧区。煤层自燃后,煤层及其上下岩层转变为烧变岩。该类岩石裂隙发育,储水条件良好,成为重要的水资源富集区,不仅对河谷径流具有重要补给作用,也是浅埋煤层上覆关键含水层之一。通过地面... 陕北重要煤炭基地广泛分布着因煤层自燃形成的火烧区。煤层自燃后,煤层及其上下岩层转变为烧变岩。该类岩石裂隙发育,储水条件良好,成为重要的水资源富集区,不仅对河谷径流具有重要补给作用,也是浅埋煤层上覆关键含水层之一。通过地面调查、井下物探、探放水及放水试验等手段,发现张家峁煤矿15207工作面上覆的4-2煤层烧变岩中存在多处富水区,且该烧变岩与邻近的常家沟水库具有水力联系,对矿井安全生产构成威胁。基于研究区内烧变岩的分布与富水特征,提出了相应的烧变岩水防治建议,在保护地下水资源的同时,也保障了矿井的安全生产。 展开更多
关键词 烧变岩 地面调查 音频电透视 探放水 放水试验
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烧变岩渗流特征及注浆减渗规律实验研究
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作者 钱自卫 谭春智 +2 位作者 孙强 王海 张改玲 《煤田地质与勘探》 北大核心 2025年第7期90-100,共11页
【背景】烧变岩区是煤层自燃形成的特殊地质体,其内部发育的孔洞裂隙系统为地下水赋存与运移提供了优势空间,但对邻近煤层安全开采构成严重水害威胁。【方法】针对这一工程难题,采用三维重构技术系统解析烧变岩内部空隙结构特征,并通过... 【背景】烧变岩区是煤层自燃形成的特殊地质体,其内部发育的孔洞裂隙系统为地下水赋存与运移提供了优势空间,但对邻近煤层安全开采构成严重水害威胁。【方法】针对这一工程难题,采用三维重构技术系统解析烧变岩内部空隙结构特征,并通过室内渗流实验与注浆实验,揭示典型烧变岩的渗流规律与注浆减渗机制。【结果和结论】(1)烧变岩试样内部孔洞裂隙高度发育,空隙结构呈现复杂多变的空间展布特征,贯通大孔裂隙占总空隙的56.72%,主要孔裂隙网络间连通性一般。(2)渗流实验表明,烧变岩渗流水力梯度与流速呈现显著非线性特征,其渗流动力学行为符合Forch-heimer方程表征规律,不同渗流方向的渗透性差异显著,渗透系数相差约50%。(3)黏土水泥浆在烧变岩孔裂隙系统中具有良好的可注性,其有效扩散距离主要受孔裂隙喉道的几何约束效应控制,随着与注浆口的距离增大,浆液对孔裂隙的充填比例逐渐降低。(4)烧变岩注浆后减渗效果显著,被注体的渗流水力梯度与流速仍呈现非线性特征,且注浆后14d内减渗率随时间延长逐渐增长并最终趋于稳定。研究成果为烧变岩区煤层开采水害防治提供了的理论依据与技术参考。 展开更多
关键词 烧变岩 三维重构 渗流特征 孔洞裂隙 注浆减渗
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CT引导下可控温度燔刺新吾穴治疗丛集性头痛临床应用探讨
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作者 刘静 杨文龙 +2 位作者 孙钦然 王寿兰 刘方铭 《中医临床研究》 2025年第14期115-119,共5页
丛集性头痛是发生于单侧眼眶、眶上和/或颞部的重度或极重度疼痛,可伴随眼部疼痛或自主神经症状,发作具有丛集性和周期性。丛集性头痛属于中医学中“头痛”“头风”的范畴。新吾穴由李新吾教授首次提出,对应解剖学中蝶腭神经节位置,蝶... 丛集性头痛是发生于单侧眼眶、眶上和/或颞部的重度或极重度疼痛,可伴随眼部疼痛或自主神经症状,发作具有丛集性和周期性。丛集性头痛属于中医学中“头痛”“头风”的范畴。新吾穴由李新吾教授首次提出,对应解剖学中蝶腭神经节位置,蝶腭神经节参与的三叉神经–自主神经反射在丛集性头痛发病机制中具有重要作用,故选择新吾穴作为丛集性头痛的治疗靶点。本团队认为,丛集性头痛的致痛原因主要为气血精微不能上荣,经脉失养,“不荣则痛”;经气不通,气血瘀痹,“不通则痛”;阴阳升降不相因,气机升降失衡,“不平则痛”。燔针释为“烧针”,即温针,该治疗方法主要从燔刺“温”“通”“平”的治疗效应出发,针对“不荣则痛”“不通则痛”“不平则痛”的致痛原因,通过针刺和热的双重作用濡养经脉,从而鼓舞正气,促进气血有序运行,以扶正祛邪,恢复阴平阳秘的生理状态。临床以温、通、平三法燔刺新吾穴治疗丛集性头痛具有较好疗效,CT引导有助于明确靶点,更好地规划进针方向、角度、深度及针尖到达位置,提高针刺的准确度、温度的可控性,既可以调整温度以适应治疗变化,又能减少热耗损,为燔刺的规范化治疗提供更多的临床证据。 展开更多
关键词 燔刺 丛集性头痛 新吾穴 温通平三法 CT引导
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基于Landsat影像评估鸡足山火烧迹地近40年植被恢复动态 被引量:1
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作者 苏维翰 张楚然 +6 位作者 邓云 翟德利 张明达 李生发 李逢昌 唐志忠 林露湘 《生态学报》 北大核心 2025年第3期1362-1378,共17页
大范围、高强度的森林火灾能够摧毁地表植被并重启群落演替进程,是影响滇中地区森林生态系统稳定的重要干扰因素之一,但当地这些火烧事件的干扰边界和随后的植被恢复动态目前仍缺乏足够的定量报道。以大理鸡足山亚热带半湿润常绿阔叶林... 大范围、高强度的森林火灾能够摧毁地表植被并重启群落演替进程,是影响滇中地区森林生态系统稳定的重要干扰因素之一,但当地这些火烧事件的干扰边界和随后的植被恢复动态目前仍缺乏足够的定量报道。以大理鸡足山亚热带半湿润常绿阔叶林分布区内1984年5月3日发生火灾的火烧迹地为主要研究对象,基于1986-2023年的Landsat多时序影像,尝试以差值归一化燃烧指数(difference Normalized Burn Ratio,dNBR)对当地历史火烧事件的火烈度边界进行定量划分,以地形因子和多重比较对不同火烈度区域间空间分布格局差异进行解释和分析;以植被覆盖度(Fractional Vegetation Cover,FVC)、归一化燃烧指数(Normalized Burn Ratio,NBR)和燃烧恢复率(Burn Recovery Ratio,BRR)等遥感植被指数时序变化和分段线性回归模型对火烧迹地上的植被恢复阶段进行定量区分,结合气温和降水等气候因子的时序变化对植被恢复过程中的重要时间拐点进行解释,并以林冠高度特征对火烧迹地目前的植被恢复程度进行评价。研究结果表明:当地1984年时的总过火面积应不小于1423.71 hm^(2),火烧迹地可划分为轻度、中低度、中高度和重度等四个火烈度(Fire severity)等级,面积比例分别为63.39%、30.73%、5.85%和0.03%,坡度较小则火烈度可能越高;轻度和中低度火烈度区可分为快速恢复(1986-1996年)和降速恢复阶段(1996年至今),中高度和重度火烈度区可分为快速恢复(1986-1990年)、降速恢复(1990-1996年)和稳定(1996年至今)阶段,但气候因子并未表现出类似的阶段性变化,遥感植被指数的时间动态更多与植被演替过程中的树种迭代过程有关;各火烈度区域内的林冠平均高度至今仍较对照区(26.4 m)偏低,林冠结构和森林地上生物量应仍处于恢复过程中。当地火烧迹地上的森林经过40年的恢复后应仍处于次生演替的前中期,亚热带半湿润常绿阔叶林的恢复是一个复杂且长期的过程。 展开更多
关键词 卫星遥感 多光谱 火烈度 火烧迹地 植被恢复
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乳酸镁和葡萄糖酸镁对轻烧MgO水化行为的影响
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作者 周晶 王周福 +4 位作者 刘浩 马妍 夏忠锋 全正煌 邓承继 《耐火材料》 北大核心 2025年第4期297-301,共5页
为优化轻烧氧化镁的水化行为,以轻烧氧化镁为原料,乳酸镁和葡萄糖酸镁为调凝剂,通过对轻烧MgO的水化程度、水化热和低场核磁共振氢谱(1H-NMR)进行表征,研究2种调凝剂(乳酸镁、葡萄糖酸镁)对轻烧MgO凝结时间及水化产物显微形貌的影响。... 为优化轻烧氧化镁的水化行为,以轻烧氧化镁为原料,乳酸镁和葡萄糖酸镁为调凝剂,通过对轻烧MgO的水化程度、水化热和低场核磁共振氢谱(1H-NMR)进行表征,研究2种调凝剂(乳酸镁、葡萄糖酸镁)对轻烧MgO凝结时间及水化产物显微形貌的影响。结果表明:相对于乳酸镁,葡萄糖酸镁对轻烧MgO水化、硬化行为和水化产物显微形貌的影响更为明显;引入3%(w)乳酸镁水化50 h累计放热量约为400 J·g^(-1),初凝时间为15 min,水化产物晶体形貌呈薄片花瓣状;引入3%(w)葡萄糖酸镁水化50 h累计放热量约为300 J·g^(-1),初凝时间延长至45 min,水化产物晶体形貌呈六方板形或四方双锥形。 展开更多
关键词 轻烧MgO 调凝剂 水化行为 乳酸镁 葡萄糖酸镁
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