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An improved high efficiency low error substrate integrated waveguide wideband delay line
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作者 ZHANG Hongxi WANG Pei 《中国科学院大学学报(中英文)》 北大核心 2025年第5期677-685,共9页
In this paper,a wideband true time delay line for X-band is designed to overcome the beam dispersion problem in a high-resolution spaceborne synthetic aperture radar phased array antenna system.The delay line loads th... In this paper,a wideband true time delay line for X-band is designed to overcome the beam dispersion problem in a high-resolution spaceborne synthetic aperture radar phased array antenna system.The delay line loads the electromagnetic bandgap structure on the upper surface of the substrate integrated waveguide.This is equivalent to including an additional inductance-capacitance for energy storage,which realizes the slow-wave effect.A microstrip line-SIW tapered transition structure is introduced to achieve a low loss and a large bandwidth.In the frequency band between 8-12 GHz,the measured results show that the delay multiplier of the delay line reaches 4 times,i.e.,delay line’s delay time is 4 times larger than 50Ωmicrostrip line with same length.Furthermore,the delay fluctuation,i.e.,the difference between the maximum and minimum delay as a percentage of the standard delay is only 2.5%,the insertion loss is less than-2.5 dB,and the return loss is less than-15 dB.Compared with the existing delay lines,the proposed delay line has the advantages of high delay efficiency,low delay error,wide bandwidth and low loss,which has good practical value and application prospects. 展开更多
关键词 SIW EBG low error high efficiency WIDEBAND
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The use of a ternary metal sulfide loading on carbon fibers as the sulfur host for high performance low-temperature lithium sulfur batteries
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作者 HE Xin ZUO Huai-yang +4 位作者 XIAO Ru QU Zhuo-yan SUN Zhen-hua WANG Bao Li Feng 《新型炭材料(中英文)》 北大核心 2025年第1期167-177,共11页
The use of lithium-sulfur(Li-S)batteries is limited by sulfur redox reactions involving multi-phase transformations,especially at low-temperatures.To address this issue,we report a material(FCNS@NCFs)consisting of nit... The use of lithium-sulfur(Li-S)batteries is limited by sulfur redox reactions involving multi-phase transformations,especially at low-temperatures.To address this issue,we report a material(FCNS@NCFs)consisting of nitrogen-doped carbon fibers loaded with a ternary metal sulf-ide((Fe,Co,Ni)_(9)S_(8))for use as the sulfur host in Li-S batteries.This materi-al was prepared using transfer blot filter paper as the carbon precursor,thiourea as the source of nitrogen and sulfur,and FeCl_(3)·6H_(2)O,CoCl_(2)·6H_(2)O and NiCl_(2)·6H_(2)O as the metal ion sources.It was synthesized by an impreg-nation method followed by calcination.The nitrogen doping significantly in-creased the conductivity of the host,and the metal sulfides have excellent catalytic activities.Theoretical calculations,and adsorption and deposition experiments show that active sites on the surface of FCNS@NCFs selectively adsorb polysulfides,facilitate rapid adsorption and conversion,prevent cathode passivation and inhib-it the polysulfide shuttling.The FCNS@NCFs used as the sulfur host has excellent electrochemical properties.Its initial dis-charge capacity is 1639.0 mAh g^(−1) at 0.2 C and room temperature,and it remains a capacity of 1255.1 mAh g^(−1) after 100 cycles.At−20~C,it has an initial discharge capacity of 1578.5 mAh g^(−1) at 0.2 C,with a capacity of 867.5 mAh g^(−1) after 100 cycles.Its excellent performance at both ambient and low temperatures suggests a new way to produce high-performance low-temper-ature Li-S batteries. 展开更多
关键词 Lithium sulfur batteries low temperature Transition metal sulfides Sulfur conversion kinetics
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Infrared-NeRF:a low resolution thermal infrared light field 3D reconstruction method based on NeRF
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作者 HUANG Yi-Fan WANG Rui +2 位作者 DENG Li-Ming LI Jia-Jia LI Xi-Cai 《红外与毫米波学报》 北大核心 2025年第4期605-616,共12页
This article proposes a three-dimensional light field reconstruction method based on neural radiation field(NeRF)called Infrared NeRF for low resolution thermal infrared scenes.Based on the characteristics of the low ... This article proposes a three-dimensional light field reconstruction method based on neural radiation field(NeRF)called Infrared NeRF for low resolution thermal infrared scenes.Based on the characteristics of the low resolution thermal infrared imaging,various optimizations have been carried out to improve the speed and accuracy of thermal infrared 3D reconstruction.Firstly,inspired by Boltzmann's law of thermal radiation,distance is incorporated into the NeRF model for the first time,resulting in a nonlinear propagation of a single ray and a more accurate description of the physical property that infrared radiation intensity decreases with increasing distance.Secondly,in terms of improving inference speed,based on the phenomenon of high and low frequency distribution of foreground and background in infrared images,a multi ray non-uniform light synthesis strategy is proposed to make the model pay more attention to foreground objects in the scene,reduce the distribution of light in the background,and significantly reduce training time without reducing accuracy.In addition,compared to visible light scenes,infrared images only have a single channel,so fewer network parameters are required.Experiments using the same training data and data filtering method showed that,compared to the original NeRF,the improved network achieved an average improvement of 13.8%and 4.62%in PSNR and SSIM,respectively,while an average decreases of 46%in LPIPS.And thanks to the optimization of network layers and data filtering methods,training only takes about 25%of the original method's time to achieve convergence.Finally,for scenes with weak backgrounds,this article improves the inference speed of the model by 4-6 times compared to the original NeRF by limiting the query interval of the model. 展开更多
关键词 neural radiation field 3D reconstruction thermal infrared NeRF foreground segmentation low resolution
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Enhanced Ion Sampling Techniques for In-situ Neutral Gas and Low-energy Ions Exploration of Main-belt Comet
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作者 WANG Xinyue ZHANG Aibing +4 位作者 SU Bin DU Dan KONG Linggao TIAN Zheng ZHENG Xiangzhi 《空间科学学报》 北大核心 2025年第3期749-760,共12页
One of the detection objectives of the Chinese Asteroid Exploration mission is to investigate the space environment near the Main-belt Comet(MBC,Active Asteroid)311P/PANSTARRS.This paper outlines the scientific object... One of the detection objectives of the Chinese Asteroid Exploration mission is to investigate the space environment near the Main-belt Comet(MBC,Active Asteroid)311P/PANSTARRS.This paper outlines the scientific objectives,measurement targets,and measurement requirements for the proposed Gas and Ion Analyzer(GIA).The GIA is designed for in-situ mass spectrometry of neutral gases and low-energy ions,such as hydrogen,carbon,and oxygen,in the vicinity of 311P.Ion sampling techniques are essential for the GIA's Time-of-Flight(TOF)mass analysis capabilities.In this paper,we present an enhanced ion sampling technique through the development of an ion attraction model and an ion source model.The ion attraction model demonstrates that adjusting attraction grid voltage can enhance the detection efficiency of low-energy ions and mitigate the repulsive force of ions during sampling,which is influenced by the satellite's surface positive charging.The ion source model simulates the processes of gas ionization and ion multiplication.Simulation results indicate that the GIA can achieve a lower pressure limit below 10-13Pa and possess a dynamic range exceeding 10~9.These performances ensure the generation of ions with stable and consistent current,which is crucial for high-resolution and broad dynamic range mass spectrometer analysis.Preliminary testing experiments have verified GIA's capability to detect gas compositions such as H2O and N2.In-situ measurements near 311P using GIA are expected to significantly contribute to our understanding of asteroid activity mechanisms,the evolution of the atmospheric and ionized environments of main-belt comets,the interactions with solar wind,and the origin of Earth's water. 展开更多
关键词 neutral gas low energy ions sampling techniques ion sampling techniques investigate space environment main belt comet gas ion analyzer gia situ measurement
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不同切片厚度对HER2-low及HER2-0乳腺癌免疫组化检测的影响 被引量:1
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作者 季盼 陈刚 +1 位作者 韩雪 宋国新 《临床与实验病理学杂志》 北大核心 2025年第4期546-548,共3页
目的通过比较不同切片厚度对HER2低表达(HER2-low)及HER2不表达(HER2-0)乳腺癌免疫组化检测结果的影响,以筛选出最适合HER-2低表达及零表达乳腺癌样本免疫组化检测的切片厚度。方法收集150例HER2阴性的浸润性乳腺癌标本,其中HER2-0、HER... 目的通过比较不同切片厚度对HER2低表达(HER2-low)及HER2不表达(HER2-0)乳腺癌免疫组化检测结果的影响,以筛选出最适合HER-2低表达及零表达乳腺癌样本免疫组化检测的切片厚度。方法收集150例HER2阴性的浸润性乳腺癌标本,其中HER2-0、HER2-1+以及HER2-2+且FISH检测为阴性的病例各50例。所有的组织样本各切2、4、6、8μm四种厚度,并进行HER2免疫组化染色,由专业的病理医师进行结果判读。结果随着切片厚度的增加,乳腺癌病变部位细胞膜HER2染色逐渐加深,同时完整胞膜染色比例增加。当切片厚度为4μm时,制片较易,细胞胞膜完整,细胞核清晰,染色对比鲜明,非特异性染色少,背景干净,细胞重叠少,更利于细胞计数和染色结果的准确分析。结论对于HER2-low及HER2-0的乳腺癌,建议切片厚度4μm,可获得较为稳定可靠的结果,较为推荐。 展开更多
关键词 乳腺肿瘤 HER2低表达 切片厚度 免疫组织化学
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Screening cotton cultivars for low-phosphorus tolerance:a comparison of hydroponic and field methods
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作者 SUN Miao DONG Helin +5 位作者 HAN Huimin FENG Weina SHAO Jingjing HUO Feichao LI Pengcheng ZHENG Cangsong 《Journal of Cotton Research》 2025年第1期89-101,共13页
Background Soil available phosphorus(AP)deficiency significantly limits cotton production,particularly in arid and saline-alkaline regions.Screening cotton cultivars for low phosphorus(P)tolerance is crucial for the s... Background Soil available phosphorus(AP)deficiency significantly limits cotton production,particularly in arid and saline-alkaline regions.Screening cotton cultivars for low phosphorus(P)tolerance is crucial for the sustainable development of cotton production.However,the effect of different growth media on the screening outcomes remains unclear.To address this,we evaluated the low P tolerance of 25 cotton cultivars through hydroponic culture at two P levels(0.01 and 0.5 mmol·L^(-1) KH_(2)PO_(4))in 2018 and field culture with two P rates(0 and 90 kg·hm^(-2),in P2O5)in 2019.Results In the hydroponic experiments,principal component analysis(PCA)showed that shoot dry weight(SDW)and P utilization efficiency in shoots(PUES)of cotton seedlings explained over 45%of the genetic variation in P nutri-tion.Cotton cultivars were subjected to comprehensive cluster analysis,utilizing agronomic traits(SDW and PUES)during the seedling stage(hydroponic)and yield and fiber quality traits during the mature stage(in field).These cultivars were grouped into four clusters:resistant,moderately resistant,moderately sensitive,and sensitive.In low P conditions(0.01 mmol·L^(-1) KH_(2)PO_(4) and 4.5 mg·kg^(-1) AP),the low-P-resistant cluster showed significantly smaller reduc-tions in SDW(54%),seed cotton yield(3%),lint yield(-2%),fiber length(-1)%),and fiber strength(-3%)compared with the low-P-sensitive cluster(75%,13%,17%,7%,and 9%,respectively).The increase in PUES(299%)in the resist-ant cluster was also significantly higher than in the sensitive cluster(131%).Four of the eight low-P-tolerant cotton cultivars identified in the field and six in the hydroponic screening overlapped in both screenings.Two cultivars overlapped in both screening in the low-P-sensitive cluster.Conclusion Based on the screenings from both field and hydroponic cultures,ZM-9131,CCRI-79,JM-958,and J-228 were identified as low-P-tolerant cotton cultivars,while JM-169,XM-33B,SCRC-28,and LNM-18 were identified as low P-sensitive cotton cultivars.The relationship between field and hydroponic screening results for low-P-tolerant cotton cultivars was strong,although field validation is still required.The low P tolerance of these cultivars was closely associ-ated with SDW and PUES. 展开更多
关键词 COTTON Hydroponic culture Field culture low phosphorus tolerance Yield Fiber quality
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Low Temperature Sintering of ZnAl_(2)O_(4) Ceramics with CuO-TiO_(2)-Nb_(2)O_(5) Composite Oxide Sintering Aid
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作者 YANG Yan ZHANG Faqiang +3 位作者 MA Mingsheng WANG Yongzhe OUYANG Qi LIU Zhifu 《无机材料学报》 北大核心 2025年第6期711-718,I0009-I0011,共11页
ZnAl_(2)O_(4) and ZnAl_(2)O_(4)-based ceramics have attracted much attention from researchers due to their good microwave dielectric,thermal and mechanical properties.In this work,the influence of 5%(in mass)CuO-TiO_(... ZnAl_(2)O_(4) and ZnAl_(2)O_(4)-based ceramics have attracted much attention from researchers due to their good microwave dielectric,thermal and mechanical properties.In this work,the influence of 5%(in mass)CuO-TiO_(2)-Nb_(2)O_(5)(CTN)ternary composite oxide additives with different composition ratios on sintering behavior and properties of ZnAl_(2)O_(4) microwave dielectric ceramics was investigated.When the molar fraction ranges of Cu,Ti and Nb elements in 5%CTN additives are 0.625-0.875,0-0.250 and 0.125-0.625,respectively,sintering temperature of ZnAl_(2)O_(4) ceramics can be reduced from above 1400℃to below 1000℃.The sintering additives CN(Cu:Nb=1:1,molar ratio)and CTN(Cu:Ti:Nb=4:1:3,molar ratio)can reduce sintering temperature of ZnAl_(2)O_(4) ceramics to 975 and 1000℃,respectively,while maintaining good dielectric properties(dielectric constantε_(r)=11.36,quality factor Q׃=8245 GHz andε_(r)=9.52,Q׃=22249 GHz)and flexural strengths(200 and 161 MPa),which are expected to be applied in preparation of low temperature co-fired ceramic(LTCC)materials with copper electrodes.Low-temperature sintering of the ZnAl_(2)O_(4)+CTN system is characterized as activated sintering.Nanometer-level amorphous interfacial films containing Cu,Ti,and Nb elements are observed at the grain boundaries,which may provide fast diffusion pathways for mass transportation during the sintering process.Valence changes of Ti and Cu ions,along with changes of oxygen vacancies,are confirmed,which provides a potential mechanism for reduced sintering temperature of ZnAl_(2)O_(4) ceramics.In addition,a series of reactions occurring at the grain boundaries can activate these boundaries and further promote the sintering densification process.These results suggest a promising way to design a novel LTCC material with excellent properties based on the low temperature sintering of ceramics with the sintering aid of CuO-TiO_(2)-Nb_(2)O_(5) composite oxide. 展开更多
关键词 ZnAl_(2)O_(4) CuO-TiO_(2)-Nb_(2)O_(5) low-temperature sintering microwave dielectric ceramic low temperature co-fired ceramic
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Robust microwave catalytic decomposition of H_(2)S into H_(2) and S at low temperature over Mo_(2)C@CeO_(2) catalysts
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作者 SUN Hongyang CHEN Jun +2 位作者 TU Cong ZHOU Jicheng XU Wentao 《燃料化学学报(中英文)》 北大核心 2025年第9期1399-1415,I0027,I0028,共19页
The new technology of direct decomposition of H_(2)S into high value-added H_(2) and S,as an alternative to the Claus process in industry,is an ideal route that can not only deal with toxic and abundant H_(2)S waste g... The new technology of direct decomposition of H_(2)S into high value-added H_(2) and S,as an alternative to the Claus process in industry,is an ideal route that can not only deal with toxic and abundant H_(2)S waste gas but also recover clean energy H_(2),which has significant socio-economic and ecological advantages.However,the highly effective decomposition of H_(2)S at low temperatures is still a great challenge,because of the stringent thermodynamic equilibrium constraints(only 20% even at high temperature of 1010℃).Conventional microwave catalysts exhibit unsatisfactory performance at low temperatures(below 600℃).Herein,Mo_(2)C@CeO_(2) catalysts with a core-shell structure were successfully developed for robust microwave catalytic decomposition of H_(2)S at low temperatures.Two carbon precursors,para-phenylenediamine(Mo_(2)C-p)and meta-phenylenediamine(Mo_(2)C-m),were employed to tailor Mo_(2)C configurations.Remarkably,the H_(2)S conversion of Mo_(2)C-p@CeO_(2) catalyst at a low temperature of 550℃ is as high as 92.1%,which is much higher than the H_(2)S equilibrium conversion under the conventional thermal conditions(2.6% at 550℃).To our knowledge,this represents the most active catalyst for microwave catalytic decomposition of H_(2)S at low temperature of 550℃.Notably,Mo_(2)C-p demonstrated superior intrinsic activity(84%)compared to Mo_(2)C-m(6.4%),with XPS analysis revealing that its enhanced performance stems from a higher concentration of Mo_(2+)active sites.This work presents a substitute approach for the efficient utilization of H_(2)S waste gas and opens up a novel avenue for the rational design of microwave catalysts for microwave catalytic reaction at low-temperature. 展开更多
关键词 direct decomposition of H_(2)S microwave catalysis low temperature microwave selective catalytic effect Mo_(x)C@CeO_(2) H_(2)production
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基于类器官构建泛TKI提高ET+CDK4/6抑制剂治疗HR^(+)/HER2-low乳腺癌疗效的筛选工具
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作者 吴迎朝 陈柳汕 +4 位作者 梁裕琪 陈洁婷 黄俊峰 左谦 陈前军 《实用医学杂志》 北大核心 2025年第18期2786-2795,共10页
目的探讨HR^(+)/HER2-low乳腺癌ET+CDK4/6抑制剂治疗效果不佳的机制,并构建乳腺癌类器官模型工具以筛选泛TKI敏感的HR^(+)/HER2-low乳腺癌患者。方法转录组学分析HR^(+)/HER2-0与HR^(+)/HER2-low乳腺癌样本差异表达基因并进行富集分析... 目的探讨HR^(+)/HER2-low乳腺癌ET+CDK4/6抑制剂治疗效果不佳的机制,并构建乳腺癌类器官模型工具以筛选泛TKI敏感的HR^(+)/HER2-low乳腺癌患者。方法转录组学分析HR^(+)/HER2-0与HR^(+)/HER2-low乳腺癌样本差异表达基因并进行富集分析。使用临床来源的乳腺癌组织构建肿瘤类器官模型,并通过Calcein-AM/PI细胞活死双染和EdU细胞增殖检测分析不同样本对治疗药物的敏感性。结果转录组学富集分析结果显示,HR^(+)/HER2-low乳腺癌的EGFR存在显著激活并具有酪氨酸激酶抑制剂耐药的特性。成功构建了乳腺癌类器官,通过药敏试验结果显示,部分HR^(+)/HER2-low乳腺癌ET+CDK4/6抑制剂治疗效果较差,TKI可以恢复HR^(+)/HER2-low乳腺癌ET+CDK4/6抑制剂治疗的敏感性(P<0.05)。结论TKI可以逆转HR^(+)/HER2-low乳腺癌对ET+CDK4/6抑制剂治疗的敏感性下降,乳腺癌类器官有望成为临床HR^(+)/HER2-low乳腺癌药敏试验筛选工具。 展开更多
关键词 乳腺癌 HR^(+)/HER2-low ET+CDK4/6抑制剂 类器官 酪氨酸激酶抑制剂
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基于Lowe分类法的5G网络EAP-AKA’协议安全性分析 被引量:19
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作者 刘彩霞 胡鑫鑫 +2 位作者 刘树新 游伟 赵宇 《电子与信息学报》 EI CSCD 北大核心 2019年第8期1800-1807,共8页
移动网鉴权认证协议攻击不断涌现,针对5G网络新协议EAP-AKA’,该文提出一种基于Lowe分类法的EAP-AKA’安全性分析模型。首先对5G网络协议EAP-AKA’、信道及攻击者进行形式化建模。然后对Lowe鉴权性质进行形式化描述,利用TAMARIN证明器... 移动网鉴权认证协议攻击不断涌现,针对5G网络新协议EAP-AKA’,该文提出一种基于Lowe分类法的EAP-AKA’安全性分析模型。首先对5G网络协议EAP-AKA’、信道及攻击者进行形式化建模。然后对Lowe鉴权性质进行形式化描述,利用TAMARIN证明器分析协议中安全锚点密钥KSEAF的Lowe鉴权性质、完美前向保密性、机密性等安全目标,发现了3GPP隐式鉴权方式下的4条攻击路径。最后针对发现的安全问题提出2种改进方案并验证其有效性,并将5G网络两种鉴权协议EAP-AKA’和5G AKA的安全性进行了对比,发现前者在Lowe鉴权性质方面更安全。 展开更多
关键词 网络安全 安全锚点密钥 EAP-AKA’ lowe分类法 Dolev-Yao敌手模型 TAMARIN
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1例婴儿Lowe综合征临床特征和OCRL基因分析 被引量:3
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作者 李冰肖 张占会 +3 位作者 周庆华 杨晶 吴瑕 柳国胜 《中国病理生理杂志》 CAS CSCD 北大核心 2016年第7期1302-1306,共5页
目的:探讨Lowe综合征的临床、影像特点及基因特征。方法:分析1例10月大Lowe综合征患儿的临床资料,头颅核磁共振(MRI)特征及其致病基因OCRL突变检测结果。结果:患儿有先天性白内障、眼球震颤、精神运动发育落后、肌张力低下、蛋白尿及血... 目的:探讨Lowe综合征的临床、影像特点及基因特征。方法:分析1例10月大Lowe综合征患儿的临床资料,头颅核磁共振(MRI)特征及其致病基因OCRL突变检测结果。结果:患儿有先天性白内障、眼球震颤、精神运动发育落后、肌张力低下、蛋白尿及血尿等临床表现。头颅MRI提示患者脑白质髓鞘发育落后,双侧额颞叶发育不良,蛛网膜下腔增宽。OCRL基因检测发现一新发缺失突变NM_000276.3:c.1280-1281del TT(p.Cys428Hisfs*2),该突变未见文献报道。结论:Lowe综合征的诊断主要通过临床表现和OCRL基因检测,本研究发现的OCRL基因新突变丰富了该基因的致病突变谱。 展开更多
关键词 lowe综合征 OCRL基因 婴儿
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基于Low rank近似的黏弹性介质衰减补偿微地震逆时定位与裂缝成像 被引量:5
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作者 唐杰 刘英昌 +1 位作者 李聪 孙成禹 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2021年第8期2858-2876,共19页
真实地下介质具有黏弹性,地震波在传播过程中会发生耗散与频散.忽视黏弹性介质的吸收衰减效应,逆时延拓过程中地震波将会出现振幅减弱、相位失真等现象,无法准确定位震源真实位置,因此需要对黏弹性介质中传播的波场进行衰减补偿,并通过... 真实地下介质具有黏弹性,地震波在传播过程中会发生耗散与频散.忽视黏弹性介质的吸收衰减效应,逆时延拓过程中地震波将会出现振幅减弱、相位失真等现象,无法准确定位震源真实位置,因此需要对黏弹性介质中传播的波场进行衰减补偿,并通过采用合适的成像算子对微地震震源进行定位与裂缝成像.本文基于耗散与频散解耦的分数阶黏弹性波动方程模拟波场,采用low rank分解近似混合域算子,分离衰减相关项并反转耗散项符号,并在补偿的衰减项波场的波数域中进行低通滤波,压制噪声的影响;使用优化后的成像算子进行微地震震源定位,并通过分离散射波场,对散射波进行逆时反传寻找裂缝.数值实验证明,本文方法通过low rank近似有效提高了计算效率,衰减补偿算子在滤波器约束下能够稳定地补偿反向延拓的波场,优化后的成像算子能够在压制随机噪声的同时进一步提高计算效率和定位分辨率. 展开更多
关键词 黏弹性 分数阶 low rank 衰减补偿 微地震 逆时定位
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B淋巴细胞白血病骨髓B细胞CD34^+CD38^+和CD34^+CD38^(low/-)细胞亚群的临床意义 被引量:3
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作者 郝乐 刘艳荣 +5 位作者 王亚哲 常艳 秦亚溱 李金兰 李玲娣 黄晓军 《中国实验血液学杂志》 CAS CSCD 北大核心 2012年第4期801-805,共5页
本研究比较发病时免疫表型为CD34+CD38+和CD34+CD38low/-两组B淋巴细胞白血病(B-ALL)的生物学特性,并探讨其临床意义。选取54例初发B-ALL并经多参数流式细胞术检测为CD34+的B-ALL患者,根据CD38表达不同将其分为CD34+CD38+组(n=35)和CD34... 本研究比较发病时免疫表型为CD34+CD38+和CD34+CD38low/-两组B淋巴细胞白血病(B-ALL)的生物学特性,并探讨其临床意义。选取54例初发B-ALL并经多参数流式细胞术检测为CD34+的B-ALL患者,根据CD38表达不同将其分为CD34+CD38+组(n=35)和CD34+CD38low/-组(n=19)。利用实时定量PCR的方法分别进行BCR-ABL,TEL-AML1和WT1基因的检测。随访标本利用7色流式细胞术检测微量残留病(MRD),平均随访时间12个月(1-28个月),平均随访间隔2个月(1-5个月)。结果表明,两组患者发病时WBC,血小板和血红蛋白水平及BCR-ABL,TEL-AML1和WT1基因阳性表达的比例均无统计学差异(P>0.05)。在诱导缓解后,CD34+CD38+组微量残留病阳性(MRD+)为28.57%(10/35),CD38low/-组MRD+为68.42%(13/19),CD34+CD38low/-组MRD+的检出率明显高于CD34+CD38+组(P<0.01)。在复发率上,CD34+CD38+组有2例,分别在第94天和第245天复发,复发率为5.71%(2/35)。CD34+CD38low/-组有7例复发,复发率为36.84%(7/19),中位复发时间263 d(46-468 d),两组间具有明显统计学差异(P<0.01)。本研究以16岁为年龄分界点,CD34+CD38+组16岁以上患者为8人(8/35),CD34+CD38low/-组16岁以上患者为10人(10/19),两组间有统计学差异(P<0.05)。结论:CD34+CD38low/-患者在成人中比例较高,且CD34+CD38low/-组在治疗后更易出现MRD+和复发。 展开更多
关键词 CD34+CD38+ CD34+CD38low/- B淋巴细胞白血病 微小残留病
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儿童Lowe综合征OCRL基因突变2例报告 被引量:2
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作者 季丽娜 陈朝英 +1 位作者 李华荣 杜培玮 《临床儿科杂志》 CAS CSCD 北大核心 2015年第6期531-534,共4页
目的探讨儿童Lowe综合征的临床特点和基因特征。方法分析2例Lowe综合征患儿的临床资料和OCRL基因检测结果,并复习相关文献。结果 2例患儿均为男性,均存在小分子蛋白尿、高钙尿症、佝偻病和肾结石。例2患儿还有轻度代谢性酸中毒、糖尿和... 目的探讨儿童Lowe综合征的临床特点和基因特征。方法分析2例Lowe综合征患儿的临床资料和OCRL基因检测结果,并复习相关文献。结果 2例患儿均为男性,均存在小分子蛋白尿、高钙尿症、佝偻病和肾结石。例2患儿还有轻度代谢性酸中毒、糖尿和隐睾症。例1患儿生后不久发现有视力异常和先天性白内障,并行手术治疗,同时存在精神运动发育落后,头颅磁共振成像(MRI)示胼胝体发育不良。例2患儿就诊时肾外症状不明显,但眼科检查发现有先天性白内障,头颅MRI示脑发育低下、脑白质髓鞘化延迟,且随访过程中逐渐出现智力发育落后。OCRL基因检测发现2个突变,例1为剪切位点突变NG 008638.1:g.46846-46848del TAA/ins C,例2为缺失移码突变NM000276.3:c.321del C,两种突变以前文献均未报道。结论 Lowe综合征的诊断主要通过临床表现和OCRL基因检测,对于有先天性白内障、肾小管病变的患儿需要与Lowe综合征鉴别。本研究发现2个OCRL基因的新突变。 展开更多
关键词 lowe综合征 OCRL基因 智力运动落后 儿童
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E-cadherin、N-cadherin与CD44^+/CD24^(-/low)表型在乳腺癌中表达的相关性及其意义 被引量:16
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作者 包俊杰 吴诚义 《中国癌症杂志》 CAS CSCD 北大核心 2010年第8期596-601,共6页
背景与目的:上皮细胞-间质转化(epithelial-mesenchymal transition,EMT)可以诱导上皮细胞来源的肿瘤表达CD44+/CD24-/low表型细胞,上皮性钙黏蛋白(E-cadherin)和神经性钙黏蛋白(N-cadherin)是分别表达于上皮细胞和间质细胞的两个重要... 背景与目的:上皮细胞-间质转化(epithelial-mesenchymal transition,EMT)可以诱导上皮细胞来源的肿瘤表达CD44+/CD24-/low表型细胞,上皮性钙黏蛋白(E-cadherin)和神经性钙黏蛋白(N-cadherin)是分别表达于上皮细胞和间质细胞的两个重要钙黏蛋白,癌细胞从E-cadherin表达向N-cadherin表达转移是EMT的一个重要机制,此钙黏蛋白转移增加了癌细胞的侵袭转移性。本研究旨在探讨CD44+/CD24-/low表型、E-cadherin及N-cadherin在乳腺癌中的表达及其意义。方法:采用免疫组织化学检测15例正常乳腺组织、20例乳腺癌癌旁组织(癌边缘2~5cm)、58例乳腺癌组织及18例腋窝转移淋巴结组织中CD44+/CD24-/low表型、E-cadherin及N-cadherin的表达,分析其与乳腺癌发生及浸润转移的关系。结果:正常乳腺组织、乳腺癌癌旁组织、乳腺癌组织和腋窝转移淋巴结组织中CD44+/CD24-/low表型表达率分别为6.7%、10.0%、41.4%和44.4%,E-cadherin阳性表达率分别为100%、90.0%、51.7%和33.3%,N-cadherin阳性表达率分别为0、15.0%、44.8%和55.6%,3种蛋白在正常乳腺组织、乳腺癌癌旁组织、乳腺癌组织和腋窝转移淋巴结组织中的表达差异均有统计学意义(P<0.05)。CD44+/CD24-/low表型表达与E-cadherin及N-cadherin表达有显著差异,且与E-cadherin表达关联程度较强,与N-cadherin表达关联程度相对较弱。E-cadherin表达与N-cadherin表达有显著差异,且具有高度相关性(P<0.05)。结论:CD44+/CD24-/low表型表达增加、E-cadherin蛋白表达降低及N-cadherin蛋白反常表达与乳腺癌的发生及浸润转移有密切的关系;在乳腺癌发展过程中,E-cadherin向N-cadherin转化及CD44+/CD24-/low表型表达增加可能发挥重要作用。 展开更多
关键词 乳腺癌 CD44+/CD24-/low表型 E-CADHERIN蛋白 N-cadherin蛋白 双重免疫组织 化学染色
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CD4^+CD25^+CD127^(low)调节性T细胞在结核性及恶性胸腔积液患者中的表达及意义 被引量:5
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作者 钱晓君 赵磊 +1 位作者 陆友金 王会平 《安徽医科大学学报》 CAS 北大核心 2013年第3期279-283,共5页
目的探讨CD4+CD25+CD127low调节性T细胞(Treg细胞)在结核性及恶性胸腔积液患者外周血及胸腔积液中的表达及其临床意义。方法收集初诊结核性及恶性胸腔积液患者各20例,采用流式细胞仪检测两组患者外周血及胸腔积液中CD4+CD25+CD127lowTre... 目的探讨CD4+CD25+CD127low调节性T细胞(Treg细胞)在结核性及恶性胸腔积液患者外周血及胸腔积液中的表达及其临床意义。方法收集初诊结核性及恶性胸腔积液患者各20例,采用流式细胞仪检测两组患者外周血及胸腔积液中CD4+CD25+CD127lowTreg细胞的表达;另外选择正常健康体检人员20例记为对照组,测定其外周血CD4+CD25+CD127lowTreg细胞的表达。结果结核性及恶性胸腔积液患者外周血CD4+CD25+CD127low占CD4+细胞比例分别为:(7.88±2.16)%、(10.46±1.37)%,较对照组(4.74±0.74)%明显升高(P<0.05);结核性和恶性胸腔积液中CD4+CD25+CD127low占CD4+细胞比例分别为:(8.45±1.39)%、(18.98±5.24)%,均高于同组别及对照组外周血水平(P<0.05),并且恶性胸腔积液中CD4+CD25+CD127low占CD4+细胞比例明显高于结核性胸腔积液(P<0.05)。结论 CD4+CD25+CD127lowTreg细胞在结核性及恶性胸腔积液患者的外周血及胸腔积液中表达比例的升高,表明其可能通过对机体免疫力的调节而参与疾病的发生发展,且其在胸腔积液中表达的高低变化可能作为结核性及恶性胸腔积液诊断的一项辅助性指标。 展开更多
关键词 CD4+CD25+CD127low调节性T细胞 结核性胸腔积液 恶性胸腔积液
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基于双振子模型在线Low-E玻璃功能层光学常量的确定 被引量:1
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作者 黄水平 徐剑 +2 位作者 王占山 鲁大学 苑同锁 《光子学报》 EI CAS CSCD 北大核心 2008年第3期473-477,共5页
从光与物质相互作用的微观机理出发,综合考虑了在线低辐射镀膜玻璃(Low-E玻璃)功能层材料中自由电子和束缚电子与光的相互作用,采用双振子模型描述了在线Low-E玻璃功能层材料的色散特性.用双振子模型所得出的理论公式对在线Low-E玻璃的... 从光与物质相互作用的微观机理出发,综合考虑了在线低辐射镀膜玻璃(Low-E玻璃)功能层材料中自由电子和束缚电子与光的相互作用,采用双振子模型描述了在线Low-E玻璃功能层材料的色散特性.用双振子模型所得出的理论公式对在线Low-E玻璃的透射谱进行了拟合,得到了Low-E玻璃功能层的光学常量.结果表明,双振子模型比Drude模型可以更准确描述在线Low-E玻璃功能层材料的光学特性,在可见光低频区和红外波段,用Drude模型描述在线Low-E玻璃功能层材料的光学特性也能得到较好的结果. 展开更多
关键词 双振子模型 在线low E玻璃 光学常量
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Low公式计算坡面流挟沙力的改进 被引量:1
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作者 李文杰 胡江 付旭辉 《重庆交通大学学报(自然科学版)》 CAS 北大核心 2012年第5期1036-1041,共6页
坡面流的挟沙能力决定着坡面土壤是否发生侵蚀或者淤积,其计算是坡面侵蚀产沙模型开发的关键。将Low公式应用于一维坡面侵蚀产沙模型,基于径流小区实测资料修正坡度项的指数对公式提出改进。结果表明:随着坡度指数的增加,侵蚀量的模拟... 坡面流的挟沙能力决定着坡面土壤是否发生侵蚀或者淤积,其计算是坡面侵蚀产沙模型开发的关键。将Low公式应用于一维坡面侵蚀产沙模型,基于径流小区实测资料修正坡度项的指数对公式提出改进。结果表明:随着坡度指数的增加,侵蚀量的模拟误差先减小后增大,存在一个临界值,使模拟误差达到最小;建议Low公式应用于坡面侵蚀产沙模型时坡度项的指数取值为0.453。 展开更多
关键词 low公式 坡面流挟沙力 一维坡面侵蚀产沙模型 改进
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硫自养反硝化技术工程应用现状及展望
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作者 陈男 陈方鑫 +8 位作者 彭彤 李冶平 孙大鑫 原源 刘程田 梅朵朵 詹永恒 汪小童 冯传平 《地学前缘》 北大核心 2026年第1期163-178,共16页
微生物反硝化是硝酸盐去除的重要方法。然而,传统的异养反硝化技术依赖外部有机碳源的添加,存在处理成本高、污泥产量大及碳排放强度高等问题。在“双碳”背景之下,寻找经济且环境友好的生物处理技术,成为低碳处理硝酸盐废水的核心问题... 微生物反硝化是硝酸盐去除的重要方法。然而,传统的异养反硝化技术依赖外部有机碳源的添加,存在处理成本高、污泥产量大及碳排放强度高等问题。在“双碳”背景之下,寻找经济且环境友好的生物处理技术,成为低碳处理硝酸盐废水的核心问题。硫自养反硝化技术使用还原态硫代替有机碳源作为电子供体驱动生物反硝化过程。与传统异养过程相比,大幅降低碳排放强度和外源碳需求。本文基于硫自养反硝化技术原理与工程应用现状,系统比较了复合型硫基材料和高硫型材料的脱氮性能,讨论了实际应用中硫自养滤料的功能特性。并基于各类反应器在结构配置、物料特性、接触方式、微生物群落富集机制等方面差异,阐释了不同类型反应器在实际应用中的性能特征。在厘清反应体系运行特性的基础上,本文综述了自养反硝化技术在市政、工业、生态等脱氮领域工程规模的应用,探讨了硫自养反硝化技术在市政污水、高盐废水及人工湿地等多场景高效脱氮应用现状,量化了硫自养技术的运行成本及环境效益。最后,展望了未来硫自养反硝化的研究方向,通过材料开发、基因工程靶向调控推动工艺标准化以突破工程化瓶颈,最终构建低碳高效的硫自养脱氮技术体系,以期为硫自养反硝化技术的工程化应用提供重要参考。 展开更多
关键词 微生物代谢 反应器构建 硫基复合材料 低碳脱氮 工程应用
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CD34+/CD38low/-/CD123+细胞表达水平对急性髓系白血病预后的意义 被引量:5
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作者 向立丽 邱国强 +3 位作者 谢晓宝 岑建农 胡绍燕 顾伟英 《中国实验血液学杂志》 CAS CSCD 北大核心 2017年第1期61-65,共5页
目的:探讨急性髓系白血病(AML)患者CD34^+/CD38^(low/-)/CD123^+细胞表达水平,并分析CD34^+/CD38^(low/-)/CD123^+表达水平与预后的相关性。方法:采用流式细胞术检测148例初诊AML患者骨髓单个核细胞中CD34^+/CD38^(low/-)/CD123^+表达水... 目的:探讨急性髓系白血病(AML)患者CD34^+/CD38^(low/-)/CD123^+细胞表达水平,并分析CD34^+/CD38^(low/-)/CD123^+表达水平与预后的相关性。方法:采用流式细胞术检测148例初诊AML患者骨髓单个核细胞中CD34^+/CD38^(low/-)/CD123^+表达水平,分析CD34^+/CD38^(low/-)/CD123^+细胞表达水平与完全缓解率、无病生存率和总体生存率相关性。结果:初诊AML患者骨髓细胞中CD34^+/CD38^(low/-)/CD123^+阳性细胞中位表达率为2.8%(0.01%-67%)。AML患者CD34^+/CD38^(low/-)/CD123^+高表达与NPM1野生型呈正相关(x^2=5.194,P=0.023),而与FLT3-ITD突变阳性无相关性(x^2=0.418,P>0.05)。多变量回归分析显示,CD34^+/CD38^(low/-)/CD123^+高表达与较低的完全缓解率(P=0.035)、较差的无病生存(P<0.001)、较短的总生存(P<0.001)相关。结论:CD34^+/CD38^(low/-)/CD123^+表达率与AML患者治疗的反应及生存密切相关,在临床中可做为快速识别患者治疗失败的风险预后指标。 展开更多
关键词 急性髓系白血病 CD34+/CD38low/-/CD123+ 预后
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