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Effect of CO_(2)flooding in an oil reservoir with strong bottom-water drive in the Tahe Oilfield,Tarim Basin,Northwest China
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作者 Li Zhang Haiying Liao Maolei Cui 《Energy Geoscience》 EI 2024年第1期230-233,共4页
The dissolution and diffusion of CO_(2)in oil and water and its displacement mechanism were investigated by laboratory experiment and numerical simulation for Block 9 in the Tahe oilfield,a sandstone oil reservoir wit... The dissolution and diffusion of CO_(2)in oil and water and its displacement mechanism were investigated by laboratory experiment and numerical simulation for Block 9 in the Tahe oilfield,a sandstone oil reservoir with strong bottom-water drive in Tarim Basin,Northwest China.Such parameters were analyzed as solubility ratio of CO_(2)in oil,gas and water,interfacial tension,in-situ oil viscosity distribution,remaining oil saturation distribution,and oil compositions.The results show that CO_(2)flooding could control water coning and increase oil production.In the early stage of the injection process,CO_(2)expanded vertically due to gravity differentiation,and extended laterally under the action of strong bottom water in the intermediate and late stages.The CO_(2)got enriched and extended at the oil-water interface,forming a high interfacial tension zone,which inhibited the coning of bottom water to some extent.A miscible region with low interfacial tension formed at the gas injection front,which reduced the in-situ oil viscosity by about 50%.The numerical simulation results show that enhanced oil recovery(EOR)is estimated at 5.72%and the oil exchange ratio of CO_(2)is 0.17 t/t. 展开更多
关键词 strong bottom-water drive reservoir CO_(2)flooding Enhanced oil recovery Coning of bottom water Tahe oilfield Tarim Basin Northwest China
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准噶尔盆地东部北10井区中深层稠油CO_(2)非混相驱油技术
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作者 许海鹏 张新奇 +3 位作者 刘蕊 夏近杰 王倩 董宏 《大庆石油地质与开发》 CAS 北大核心 2024年第1期142-148,共7页
准噶尔盆地东部北10井区头屯河组油藏具有埋藏深、原油黏度大、储层强水敏的特点,自探明以来一直未获得有效动用。为了解决油藏难动用的难题进行了CO_(2)-稠油实验,在实验结果的基础上,根据试验区生产现状提出“非混相驱+吞吐”措施,利... 准噶尔盆地东部北10井区头屯河组油藏具有埋藏深、原油黏度大、储层强水敏的特点,自探明以来一直未获得有效动用。为了解决油藏难动用的难题进行了CO_(2)-稠油实验,在实验结果的基础上,根据试验区生产现状提出“非混相驱+吞吐”措施,利用数值模拟手段优化生产参数得到最优方案并预测出生产指标。结果表明:地层稠油注入CO_(2)后原油体积膨胀和黏度降低的能力大幅增强,是提高采收率的主要机理;井区稠油CO_(2)驱替方式为非混相驱,驱替过程中CO_(2)先以溶解和扩散作用为主,待建立驱替通道后才开始产出原油,采收率为29.60%;试验区非混相驱初期见效慢,为加快受效提出“油井吞吐”措施,数值模拟预测非混相驱配合3轮油井吞吐生产,最终采收率可达21.0%,解决了研究区油藏难动用的难题。研究成果对中深层强水敏稠油油藏的动用具有一定的借鉴意义。 展开更多
关键词 中深层稠油 强水敏 CO_(2)非混相驱 提高采收率 北10井区
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基于光学影像相关性匹配技术的2023年土耳其M_(W)7.8与M_(W)7.5双强震地表同震变形研究 被引量:1
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作者 康文君 徐锡伟 《地质力学学报》 CSCD 北大核心 2024年第2期289-297,共9页
2023年2月6日在土耳其中南部卡赫拉曼马拉什省10个小时内连续发生M_(W)7.8与M_(W)7.5双强震,震源机制解表明两个地震均为走滑型地震。土耳其双强地震发生后,国内外学者利用野外测量、GNSS以及差分InSAR等方法开展了一系列地表同震变形研... 2023年2月6日在土耳其中南部卡赫拉曼马拉什省10个小时内连续发生M_(W)7.8与M_(W)7.5双强震,震源机制解表明两个地震均为走滑型地震。土耳其双强地震发生后,国内外学者利用野外测量、GNSS以及差分InSAR等方法开展了一系列地表同震变形研究,但由于所采用的技术手段限制,当前已有地表同震变形结果尚存在空间分辨率低、近断层处数据缺失等不足。为了弥补这些不足,研究利用哨兵2号光学影像数据,通过影像相关性匹配技术得到了土耳其双强震的东西向和南北向的地表同震变形场,并将这些地表变形转换成为沿着断层方向的左旋走滑位移。变形场结果显示两次地震地表破裂长度分别约280 km和约130 km,首先发生的M_(W) 7.8地震的平均走滑位移量为4.2±1.66 m,最大走滑位移量6.9±0.81 m;随后发生的M_(W)7.5地震的平均走滑位移量为4.9±2.45 m,最大走滑位移量为9.6±1.16 m。通过对比COSI-Corr方法和野外测量得到的水平位移,结果显示2种方法得到的最大水平位移相吻合,而COSI-Corr方法得到的平均位移略大于野外测量得到的水平位移,这是由COSI-Corr方法测量结果中包含了部分离断层弥散变形导致的。研究结论不仅可为断层面滑动反演模型提供变形数据和约束条件,同时可以加深对走滑断裂的破裂行为控制因素的理解。 展开更多
关键词 土耳其双强震 东安纳托利亚断裂 哨兵2 光学影像相关性匹配 地表同震变形 恰尔达克断裂
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Amine-functionalized metal organic framework@graphene oxide as filler in PAEK-containing carboxyl group membrane for ultrafiltration with ultra-high permeability and strong fouling resistance
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作者 Zhaoli Wang Wenjing Li +6 位作者 Yi Zhang Yanyin Cheng Junjian Yu Tianming Dong Xiaoyu Chi Di Liu Zhe Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第6期93-103,共11页
Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge.In this work,a novel mixed-matrix membrane(MMM)(poly(arylene ether ketone)[PAEK]... Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge.In this work,a novel mixed-matrix membrane(MMM)(poly(arylene ether ketone)[PAEK]-containing carboxyl groups[PAEK-COOH]/UiO-66-NH_(2)@graphene oxide[GO])with superb fouling resistance and high permeability was prepared by the nonsolvent-induced phase separation method,by in-situ growth of UiO-66-NH_(2) on the GO layer,and by preparing hydrophilic PAEK-COOH.On the basis of the structure and performance analysis of the MMM,the maximum water flux reached 591.25 L·m^(-2)·h^(-1) for PAEK-COOH/UiO-66-NH_(2)@GO,whereas the retention rate for bovine serum albumin increased from 85.40%to 94.87%.As the loading gradually increased,the hydrophilicity of the MMMs increased,significantly enhancing their fouling resistance.The strongest anti-fouling ability observed was 94.74%,which was 2.02 times greater than that of the pure membrane.At the same time,the MMMs contained internal amide and hydrogen bonds during the preparation process,forming a cross-linked structure,which further enhanced the mechanical strength and chemical stability.In summary,the MMMs with high retention rate,strong permeability,and anti-fouling ability were successfully prepared. 展开更多
关键词 Poly(arylene ether ketone)-containing Carboxyl groups(PAEK-COOH) UiO-66-NH_(2)@graphene oxide Hydrophilic modification Ultra-high selectivity strong anti-fouling
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镜铁山式铁矿选矿过程中K_(2)O含量走向分析
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作者 钟志刚 王红 刘升 《甘肃冶金》 2024年第3期16-19,共4页
针对镜铁山式难选氧化铁矿矿石特点及酒钢选矿厂现有工艺流程,为减少酒钢高炉吨铁碱金属负荷,尤其是K_(2)O含量,确保后续烧结及炼铁工序顺利进行,对选矿不同工艺流程中的原矿矿石性质进行研究,发现K_(2)O主要赋存矿物为白云母,镜铁山矿... 针对镜铁山式难选氧化铁矿矿石特点及酒钢选矿厂现有工艺流程,为减少酒钢高炉吨铁碱金属负荷,尤其是K_(2)O含量,确保后续烧结及炼铁工序顺利进行,对选矿不同工艺流程中的原矿矿石性质进行研究,发现K_(2)O主要赋存矿物为白云母,镜铁山矿经筛分分为强磁粉矿和块矿,块矿经过焙烧抛废后其K_(2)O含量基本稳定在0.405%,满足炼铁精矿质量要求;强磁粉矿中K_(2)O含量较高,通过考察现场强磁选流程,发现立环机及筒式磁选机对脉石矿物白云母具有一定的分选作用,在对设备运行参数进行调整后可进一步将K_(2)O富集在尾矿中,最终可获得铁精矿品位44.90%,回收率59.71%,K_(2)O品位为0.362%的合格铁精矿,为适时控制难选氧化铁矿石选别产品综合铁精矿质量提供一定的数据参考。 展开更多
关键词 镜铁山式难选氧化铁矿石 碱负荷 K_(2)O 粉矿 强磁选
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塔河油田强底水砂岩油藏CO_(2)/N_(2)驱提高采收率机理 被引量:5
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作者 刘学利 郑小杰 +3 位作者 钱德升 高海铭 谭涛 蒲万芬 《科学技术与工程》 北大核心 2023年第15期6409-6418,共10页
塔河油田强底水砂岩油藏开发后期,受强非均质性和底水锥进影响,大部分水平井出现了点状水淹,导致低产低效井增多,油藏含水率不断上升,井间剩余油动用难,且该油藏具有高温、高盐特点,常规提高采收率技术难以取得较好的开发效果。因此,主... 塔河油田强底水砂岩油藏开发后期,受强非均质性和底水锥进影响,大部分水平井出现了点状水淹,导致低产低效井增多,油藏含水率不断上升,井间剩余油动用难,且该油藏具有高温、高盐特点,常规提高采收率技术难以取得较好的开发效果。因此,主要通过高温高压三维物理模型进行油藏的模拟,采用注CO_(2)/N_(2)(体积比为7∶3)混合气提高强底水砂岩油藏采收率。一方面,CO_(2)与原油易混相,能够大幅度地提高驱油效率;另一方面,N_(2)具有较好的压锥效果,在一定程度上抑制了强底水快速锥进,提高油藏的波及系数。这样使“驱油”与“压锥”进行有机结合,大大提高了油藏采收率。同时,对比不同注气方式、不同注气速度和不同注采部位等驱油条件,优选注气参数。实验结果表明:注入CO_(2)/N_(2)后地层原油体积膨胀了21%,黏度降低了24.9%;CO_(2)/N_(2)混合气与原油的最小混相压力为39.62 MPa;优选出了最佳的注入参数:注气速度为1 mL/min(提高采收率幅度为14.25%)、注气方式为水气交替注入(提高采收率幅度为15.8%)、注采部位为高注低采(提高采收率幅度为14.5%)。研究结果为塔河油田强底水砂岩油藏CO_(2)/N_(2)混合气驱先导试验提供可靠实验依据。 展开更多
关键词 强底水砂岩油藏 CO_(2)/N_(2)混合气驱 三维物理模型 混相 压锥
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Strong ground motion simulation for the 2013 Lushan M_W6.6 earthquake, Sichuan, China, based on the inverted and synthetic slip models 被引量:1
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作者 Wenhao Shen Qiu Zhong Baoping Shi 《Earthquake Science》 2014年第4期377-389,共13页
It is well known that quantitative estimation of slip distributions on fault plane is one of the most important issues for earthquake source inversion related to the fault rupture process. The characteristics of slip ... It is well known that quantitative estimation of slip distributions on fault plane is one of the most important issues for earthquake source inversion related to the fault rupture process. The characteristics of slip distribution on the main fault play a fundamental role to control strong ground motion pattern. A large amount of works have also suggested that variable slip models inverted from longer period ground motion recordings are relevant for the prediction of higher frequency ground motions. Zhang et al. (Chin J Geophys 56:1412-1417, 2013) and Wang et al. (Chin J Geophys 56:1408-1411,2013) published their source inversions for the fault rupturing process soon after the April 20, 2013 Lushan earthquake in Sichuan, China. In this study, first, we synthesize two forward source slip models: the value of maximum slip, fault dimension, size, and dimension of major asperities, and comer wave number obtained from Wang's model is adopted to constrain the gen- eration of k-2 model and crack model. Next, both inverted and synthetic slip models are employed to simulate the ground motions for the Lushan earthquake based on the stochastic finite-fault method. In addition, for a comparison purpose, a stochastic slip model and another k-2 model (k 2 model II) with 2 times value of comer wave number of the original k-2 model (k 2 model I) are also employed for simulation for Lushan event. The simulated results characterized by Modified Mer- calli Intensity (MMI) show that the source slip models based on the inverted and synthetic slip distributions could capture many basic features associated with the ground motion patterns. Moreover, the simulated MMI distributions reflect the rupture directivity effect and the influence of the shallow velocity structure well. On the other hand, the simulated MMI bystochastic slip model and k 2 model II is apparently higher than observed intensity. By contrast, our simulation results show that the higher frequency ground motion is sensitive to the degree of slip roughness; therefore, we suggest that, for realistic ground- motion simulations due to future earthquake, it is imperative to properly estimate the slip roughness distribution. 展开更多
关键词 Stochastic finite-fault model strong groundmotion -2013 Lushan Mw6.6 earthquake Corner wavenumber k -2 model Crack model
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CaTiF_(6)·2H_(2)O:Mn^(4+)窄带红色荧光粉的发光性能及其高显指暖白光LED应用 被引量:4
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作者 陈孔岚 张学亮 +4 位作者 宋恩海 周亚运 袁健 樊婷 邓婷婷 《发光学报》 EI CAS CSCD 北大核心 2023年第2期259-270,共12页
报道了一种新型的Mn^(4+)掺杂水合六氟钛酸钙CaTiF_(6)·2H_(2)O:Mn^(4+)红色荧光粉,详细研究了基质的结构转变和荧光粉的发光性能及高显色指数(显指)暖白光LED应用。CaTiF_(6)·2H_(2)O:Mn^(4+)在130~200℃间脱水转化为CaTiF_(... 报道了一种新型的Mn^(4+)掺杂水合六氟钛酸钙CaTiF_(6)·2H_(2)O:Mn^(4+)红色荧光粉,详细研究了基质的结构转变和荧光粉的发光性能及高显色指数(显指)暖白光LED应用。CaTiF_(6)·2H_(2)O:Mn^(4+)在130~200℃间脱水转化为CaTiF_(6):Mn^(4+),荧光光谱发生改变,重新吸附水分子可恢复到CaTiF_(6)·2H_(2)O:Mn^(4+),发光性能不可逆。重要的是,该荧光粉在较长波626 nm和635 nm处分别发射锐线极强的零声子线(ZPL)和ν6振动峰,色坐标为(0.701,0.299),更接近人眼敏感的红光边界650 nm(色坐标x~0.72,y~0.28),有助于提高暖白光LED的显色指数、拓宽背光源的色域。晶体结构和晶体场强度计算指出,Mn^(4+)在CaTiF_(6)·2H_(2)O:Mn^(4+)中占据低对称性的格位,所受到的晶体场强度较弱,Mn—F键的共价性较强。另外,通过表面疏水化显著提升了荧光粉耐湿性能,共掺小离子半径的Si^(4+)增强了荧光粉发光热稳定性。以CaTiF_(6)·2H_(2)O:Mn^(4+)作为红光成分,获得了高显色指数(R_(a)=90,R_(9)=68)的暖白光LED,在高品质的暖白光照明中具有潜在的应用。 展开更多
关键词 Mn^(4+)掺杂氟化物 CaTiF_(6)·2H_(2)O:Mn^(4+) 极强零声子线 高显色指数 暖白光LED
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SWOT Analysis on Agricultural Enterprises Implementing B2C E-commerce——A Case Study of Wuding Strong Chicken Farming Enterprises 被引量:1
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作者 Dekun WANG Wan NIE 《Asian Agricultural Research》 2017年第12期55-58,共4页
This paper first introduced current situations of agricultural enterprises using B2C e-commerce to sell agricultural products.Then,using SWOT method,it analyzed strengths,weaknesses,opportunities,and threats of Wuding... This paper first introduced current situations of agricultural enterprises using B2C e-commerce to sell agricultural products.Then,using SWOT method,it analyzed strengths,weaknesses,opportunities,and threats of Wuding strong chicken farming enterprises implementing B2C e-commerce.Finally,it came up with recommendations for Wuding strong chicken farming enterprises implementing B2C e-commerce. 展开更多
关键词 Wuding strong chicken B2C E-COMMERCE SWOT
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INFINITE SERIES FORMULAE RELATED TO GAUSS AND BAILEY 2F1(1/2)-SUMS
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作者 初文昌 《Acta Mathematica Scientia》 SCIE CSCD 2020年第2期293-315,共23页
The unifiedΩ-series of the Gauss and Bailey2F1(1/2)-sums will be investigated by utilizing asymptotic methods and the modified Abel lemma on summation by parts.Several remarkable transformation theorems for theΩ-ser... The unifiedΩ-series of the Gauss and Bailey2F1(1/2)-sums will be investigated by utilizing asymptotic methods and the modified Abel lemma on summation by parts.Several remarkable transformation theorems for theΩ-series will be proved whose particular cases turn out to be strange evaluations of nonterminating hypergeometric series and infinite series identities of Ramanujan-type,including a couple of beautiful expressions forπand the Catalan constant discovered by Guillera(2008). 展开更多
关键词 Abel's lemma on summation by parts classical hypergeometric series Gauss'2F1(1/2)-sum Bailey's 2F1(1/2)-sum Saddle point method Catalan's constant
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SOME PROPERTIES OF STRONGLY MONOTONICALLY T2 SPACES
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作者 Zhao Bin 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2005年第4期469-474,共6页
This paper investigates Buck's question about which class of spaces is strongly monotonically T2,and if other properties are combined with strongly monotonically T2,which class of spaces could be got. Based on having... This paper investigates Buck's question about which class of spaces is strongly monotonically T2,and if other properties are combined with strongly monotonically T2,which class of spaces could be got. Based on having a cushioned pair-base space and compact strongly monotonically T2 space,some results (Theorems 1--3) are obtained. 展开更多
关键词 cushioned pair-base compact strongly monotonically T2 operator strongly monotonically T2 space.
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Strong Law of Large Numbers for a 2-Dimensional Array of Pairwise Negatively Dependent Random Variables
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作者 Karn Surakamhaeng Nattakarn Chaidee Kritsana Neammanee 《Open Journal of Statistics》 2013年第1期42-46,共5页
In this paper, we obtain the strong law of large numbers for a 2-dimensional array of pairwise negatively dependent random variables which are not required to be identically distributed. We found the sufficient condit... In this paper, we obtain the strong law of large numbers for a 2-dimensional array of pairwise negatively dependent random variables which are not required to be identically distributed. We found the sufficient conditions of strong law of large numbers for the difference of random variables which independent and identically distributed conditions are regarded. In this study, we consider the limit as which is stronger than the limit as m× n→?∞ when m, n →?∞?are natural numbers. 展开更多
关键词 strong Law of Large NUMBERS Negatively Dependent 2-Dimensional ARRAY of Random VARIABLES
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Adsorption equilibrium, kinetics, and dynamic separation of Ca2+ and Mg2+ ions from phosphoric acid–nitric acid aqueous solution by strong acid cation resin
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作者 Rui Lü Qing Xi +7 位作者 Tan Li Rui Li Xiaochao Zhang Jianxin Liu Caimei Fan Junqiang Feng Lingyun Zhang ZhihuaWang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2019年第12期2930-2936,共7页
The separation of Ca2+and Mg2+ions from phosphoric acid-nitric acid aqueous solution is very significant for the neutralization process of nitrophosphate fertilizer.This paper studied the adsorption equilibrium,kineti... The separation of Ca2+and Mg2+ions from phosphoric acid-nitric acid aqueous solution is very significant for the neutralization process of nitrophosphate fertilizer.This paper studied the adsorption equilibrium,kinetics,and dynamic separation of Ca2+and Mg2+ions by strong acid cation resin,and the effects of phosphoric acid and nitric acid on the adsorption process were investigated.The results reveal that the adsorption process of Ca2+and Mg2+ions in pure water on resin is in good agreement with the Langmuir isotherm model and their maximal adsorption capacities are 1.86 mmol·g-1 and 1.83 mmol·g-1,respectively.The adsorption kinetics of Ca2+and Mg2+ions on resin fits better with the pseudo-first-order model,and the adsorption equilibrium in pure water is reached within 10 min contact time,while at the present of phosphoric acid,the adsorption rate of Ca2+and Mg2+ions on resin will go down.The dynamic separation experiments demonstrate that the designed column adsorption is able to undertake the separation of metal ions from the mix acids aqueous solution,but the dynamic operation should control the flow rate of mix acid solution.Besides nitric acid solution was proved to be effective to completely regenerate the spent resin and achieve the recyclable operation of separation process. 展开更多
关键词 Ca2+and Mg2+ions strong acid CATION resin Adsorption equilibrium KINETICS DYNAMIC SEPARATION
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Theoretical Simulation of the Infrared Absorption Spectrum of the Strong Hydrogen and Deuterium Bond in 2-Pyridone Dimer
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作者 Noureddine Issaoui Houcine Ghalla Brahim Oujia 《Open Journal of Physical Chemistry》 2012年第4期228-239,共12页
This work presents a theoretical simulation of the infrared spectra of strong hydrogen bond in alpha-phase 2-pyridone dimers, as well as in their deuterium derivatives at room temperature. The theory takes into accoun... This work presents a theoretical simulation of the infrared spectra of strong hydrogen bond in alpha-phase 2-pyridone dimers, as well as in their deuterium derivatives at room temperature. The theory takes into account an adiabatic anharmonic coupling between the high-frequency N-H(D) stretching and the low-frequency intermolecular N...O stretching modes by considering that the effective angular frequency of the fast mode N-H(D) is assumed to be strongly dependent on the slow mode stretching coordinate N...O, the intrinsic anharmonicity of the low-frequency N...O mode through a Morse potential, Davydov coupling triggered by resonance exchange between the excited states of the fast modes of the two hydrogen bonds involved in the cyclic dimer, multiple Fermi resonances between the N-H(D) stretching and the overtone of the N-H(D) bending vibrations and the direct and indirect damping of the fast stretching modes of the hydrogen bonds and of the bending modes. The IR spectral density is computed within the linear response theory by Fourier transform of the autocorrelation function of the transition dipole moment operator of the N-H(D) bond. The theoretical line shapes of the υN-H(D) band of alpha-phase 2-pyridone dimers are compared to the experimental ones. The effect of deuteration is successfully reproduced. 展开更多
关键词 strong HYDROGEN Bound ALPHA-PHASE 2-Pyridone DIMER Infrared Spectral Density Davydov Coupling MORSE Potential Fermi Resonances
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Room-temperature strong coupling between dipolar plasmon resonance in single gold nanorod and two-dimensional excitons in monolayer WSe_2
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作者 温锦秀 汪浩 +2 位作者 陈焕君 邓少芝 许宁生 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第9期144-150,共7页
All-solid-state strong coupling systems with large vacuum Rabi splitting energy have great potential applications in future quantum information technologies, such as quantum manipulations, quantum information storage ... All-solid-state strong coupling systems with large vacuum Rabi splitting energy have great potential applications in future quantum information technologies, such as quantum manipulations, quantum information storage and processing,and ultrafast optical switches. Monolayer transition metal dichalcogenides(TMDs) have recently been explored as excellent candidates for the observation of solid-state strong coupling phenomena. In this work, from both experimental and theoretical aspects, we explored the strong coupling effect by integrating an individual plasmonic gold nanorod into the monolayer tungsten diselenide(WSe2). Evident anti-crossing behavior was observed from the coupled energy diagram at room temperature; a Rabi splitting energy of 98 meV was extracted. 展开更多
关键词 Au nanorod-WSe2 heterostructures strong coupling all-solid-state system room temperature
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基于ICESat-2/ATLAS和特征参数的森林地上生物量反演
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作者 李宏菲 聂胜 +3 位作者 习晓环 王宏涛 张合兵 王成 《激光杂志》 CAS 北大核心 2023年第7期62-67,共6页
大区域森林生物量估算是植被遥感应用研究的重要内容。利用ICESat-2/ATLAS数据中ATL08产品的高度信息,结合Sentinel-2影像提取的森林覆盖度构建新型特征参数(h_(cover)_#),对原始光子参数,以及加入h_(cover)_#后两种数据,分别利用随机... 大区域森林生物量估算是植被遥感应用研究的重要内容。利用ICESat-2/ATLAS数据中ATL08产品的高度信息,结合Sentinel-2影像提取的森林覆盖度构建新型特征参数(h_(cover)_#),对原始光子参数,以及加入h_(cover)_#后两种数据,分别利用随机森林方法分析索诺玛县森林区域白天和夜晚强弱光束反演生物量的能力。结果表明:(1)相对于仅利用原始光子数据,加入新型特征参数后,四种场景的生物量估算精度均有不同程度的提高,其中,R^(2)分别提升了0.08、0.16、0.07、0.09,RMSE分别降低了7.56 Mg/ha、13.02 Mg/ha、6.45 Mg/ha、8.25 Mg/ha,rRMSE分别降低了5.13%、10.16%、4.23%、5.76%;(2)在夜晚强光束场景下,联合原始光子参数与新型特征参数构建的生物量模型预测精度最优,R^(2)=0.64,RMSE=73.50 Mg/ha,rRMSE=48.16%。 展开更多
关键词 森林地上生物量 ICESat-2/ATLAS 强光束光子点 Sentinel-2影像 随机森林 新型特征参数
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Au/CeO_(2)中强金属-载体相互作用的形貌效应
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作者 韩静茹 孙志敏 +1 位作者 李昱 胡执一 《无机化学学报》 SCIE CAS CSCD 北大核心 2023年第9期1682-1690,共9页
以Au/CeO_(2)为研究对象,通过构建不同形貌的CeO_(2)载体来研究强金属-载体相互作用(SMSI)的形貌效应。分别以纳米立方块和纳米棒作为载体,通过高分辨(扫描)透射电子显微、光电子能谱、氢程序升温还原等一系列表征方法揭示了CeO_(2)纳... 以Au/CeO_(2)为研究对象,通过构建不同形貌的CeO_(2)载体来研究强金属-载体相互作用(SMSI)的形貌效应。分别以纳米立方块和纳米棒作为载体,通过高分辨(扫描)透射电子显微、光电子能谱、氢程序升温还原等一系列表征方法揭示了CeO_(2)纳米立方块表面更易发生质量传输并形成CeO_(2-x)包覆层。此包覆层大幅抑制了催化剂对小分子气体的吸附能力,并减少了催化活性位点的暴露,对探针反应(丁二烯选择性催化加氢)的催化活性影响显著。以上研究结果表明CeO_(2)纳米立方块比CeO_(2)纳米棒更易构建SMSI体系。 展开更多
关键词 强金属-载体相互作用 Au/CeO_(2) 形貌效应 1 3-丁二烯催化加氢
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基于l_(1)-αl_(2)(0<α≤1)最小化的仿射相位恢复
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作者 王新云 黄尉 《大学数学》 2023年第4期1-6,共6页
仿射相位恢复是利用先验信息从仅限幅值测量中恢复未知信号的问题.利用l_(1)-αl_(2)(0<α≤1)最小化模型,研究如何稳定的重建稀疏的未知信号,当测量矩阵满足一定的强约束等距性质时,证明未知信号x∈ℝ^(n)可以被稳定的恢复出来.重点... 仿射相位恢复是利用先验信息从仅限幅值测量中恢复未知信号的问题.利用l_(1)-αl_(2)(0<α≤1)最小化模型,研究如何稳定的重建稀疏的未知信号,当测量矩阵满足一定的强约束等距性质时,证明未知信号x∈ℝ^(n)可以被稳定的恢复出来.重点讨论l_(2)有界噪声和Dantzig Selector噪声情况下的恢复条件. 展开更多
关键词 仿射相位恢复 l_(1)-αl_(2)(0<α≤1)最小化 强约束等距性质
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Al促进SO_ 4^(2-)/M_xO_y(M=Zr,Ti,Fe)固体强酸的研究 被引量:42
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作者 夏勇德 华伟明 高滋 《化学学报》 SCIE CAS CSCD 北大核心 2000年第1期86-91,共6页
合成与表征了三个系列的Al促进固体强酸样品,并研究了对甲苯的苯甲酰化反应性能.实验表明,SO_4^(2-)/ZrO_2,SO_4^(2-)/TiO_2和SO_4^(2-)/Fe_2O_3中引入适量的Al_2O_3,有助于稳定样品表面的含硫物种,增加样品表面的有效酸位,提高样品的... 合成与表征了三个系列的Al促进固体强酸样品,并研究了对甲苯的苯甲酰化反应性能.实验表明,SO_4^(2-)/ZrO_2,SO_4^(2-)/TiO_2和SO_4^(2-)/Fe_2O_3中引入适量的Al_2O_3,有助于稳定样品表面的含硫物种,增加样品表面的有效酸位,提高样品的强酸性和对甲苯的苯甲酰化的反应活性.NH_3吸附微量热结果表明,Al促进样品的强酸性和催化活性的显著提高是由于样品表面的酸位强度分布发生了变化,有利于正丁烷异构化反应和苯甲酰化反应的中强酸位和强酸位的酸量显著增加. 展开更多
关键词 固体强酸 A1促进催化剂 石油炼制 酸催化剂
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FY-2C高时间分辨率扫描数据在强对流云团监测中的应用研究 被引量:22
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作者 刘健 蒋建莹 《大气科学》 CSCD 北大核心 2013年第4期873-880,共8页
利用我国首次获取的静止气象卫星平均10分钟观测间隔的高时间分辨率数据对2011年6月28日~29日发生的一次强对流云团特征进行分析。Hovmller分析图清晰地展示出在高时间分辨率观测条件下云团中心冷核的演变特征。高时间分辨率卫星资... 利用我国首次获取的静止气象卫星平均10分钟观测间隔的高时间分辨率数据对2011年6月28日~29日发生的一次强对流云团特征进行分析。Hovmller分析图清晰地展示出在高时间分辨率观测条件下云团中心冷核的演变特征。高时间分辨率卫星资料与地面降水量进行联合分析,可推知对流云团中冷核的演变与地面小时降水量大值的落区间有很好的一致性;10分钟雨量资料联合前推1小时内7次平均10分钟观测间隔的卫星红外1通道亮温,分析可知地面雨量较大时,云顶像元亮温具有持续降低或维持低温状态的特点。反映出在对流性强降水中,冷且具有一定稳定性的云顶是产生大降水的主要特征。研究结果显示,静止气象卫星的高时间分辨率观测可很好地捕捉到强对流云团发展的演变特征,利用FY-2C静止气象卫星红外1通道亮温、红外1通道与水汽通道亮温差在高时间分辨率观测中的时差特征变量,可实现对强对流云团初生的有效监测,为强对流云团的预测预报提供支撑。 展开更多
关键词 FY-2 快速区域扫描 强对流云团 监测
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