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Dual-polarization two-dimensional valley photonic crystals

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Science China(Physics,Mechanics & Astronomy) 2022年第8期65卷 102-109页

作者： Xin-Tao He Jian-Wei Liu fu-long shi Ke Shen Wen-Jie Chen Xiao-Dong Chen Jian-Wen Dong School of Physics State Key Laboratory of Optoelectronic Materials and TechnologiesSun Yat-sen UniversityGuangzhou510275China

The recent realization of valley physics in photonic systems has enriched the topological phases of light with protected edge modes and shown applications in designing high-performance photonic devices. However, the widely reported valley Hall effect of light in two-dimensional systems is limited to one single polarization. Here, we present dual-polarization two-dimensional valley photonic crystals by simultaneously opening two frequency accidental degenerate Dirac cones. Two band gaps with different polarizations are characterized by opposite-valley Chern numbers, which are confirmed by the opposite-phase vortex distributions of bulk modes and opposite Berry curvatures. This situation results in the polarization-dependent refraction of bulk and edge modes, which locate in opposite valleys. The polarization-independent topological valley transport is also demonstrated. Our work shows the flexible control of light in topological photonic systems with a polarization degree of freedom and has applications in polarization multiplexing photonic devices.

关键词： topological photonics valley photonic crystals polarization

Second Chern crystals with inherently non-trivial topology

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National Science Review 2023年第8期10卷 148-155页

作者： Xiao-Dong Chen fu-long shi Jian-Wei Liu Ke Shen Xin-Tao He C.T. Chan Wen-Jie Chen Jian-Wen Dong School of Physics and State Key Laboratory of Optoelectronic Materials and Technologies Sun Yat-sen University Department of Physics The Hong Kong University of Science and Technology

Chern insulators have been generalized to many classical wave systems and thereby lead to many potential applications such as robust waveguides, quantum computation and high-performance lasers. However, the band structure of a material can be either topologically trivial or non-trivial, depending on how the crystal structure is designed. Here, we propose a second Chern crystal in a four-dimensional parameter space by introducing two extra synthetic translation dimensions. Since the topology of the bulk bands in the synthetic translation space is intrinsically non-trivial, our proposed four-dimensional crystal is guaranteed to be topologically non-trivial regardless of the crystal’s detailed configuration. We derive the topologically protected modes on the lower dimensional boundaries of such a crystal via dimension ***, we observe the one-dimensional gapless dislocation modes and confirm their robustness in experiments. Our findings provide novel perspectives on topologically non-trivial crystals and may inspire designs of classical wave devices.

关键词： topological photonics synthetic dimension photonic crystals dislocation mode

基于FPGA的以太网与E1网中的同步动态随机存储控制器设计

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厦门大学学报（自然科学版） 2013年第3期52卷 360-365页

作者：符世龙陈松岩厦门大学物理与机电工程学院福建厦门361005

为了实现不同速率数据链路通信的相互转换,提出了一种利用现场可编程门序列(FPGA)设计并实现可对同步动态随机存储器(SDRAM)进行数据缓存并高速读写的控制器.该控制器采取状态机和令牌环机制,通过对SDRAM操作,实现了双向4路的跨时钟域... 详细信息

为了实现不同速率数据链路通信的相互转换,提出了一种利用现场可编程门序列(FPGA)设计并实现可对同步动态随机存储器(SDRAM)进行数据缓存并高速读写的控制器.该控制器采取状态机和令牌环机制,通过对SDRAM操作,实现了双向4路的跨时钟域的匹配.该控制器适用于任意长度的以太网帧和其他类型的数据相互转换.

关键词：同步动态随机存储器跨时钟域通信现场可编程门序列以太网帧

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肿瘤患者循环DNA的定量研究

中华肿瘤杂志 2004年第10期26卷 606-608页

作者：屠红高海峰傅士龙陈颢上海市肿瘤研究所上海交通大学肿瘤研究所 200032 复旦大学免疫学系复旦大学附属肿瘤医院

目的建立纳克水平DNA定量方法,并探讨循环DNA检测在肿瘤诊断中的应用价值。方法对483例恶性肿瘤患者以微量基因组抽提试剂盒抽提血清DNA,以SYBRgreenⅠ荧光染色法行DNA定量;BRCA1(D17S579、D17S855)和p53(TP53,D17S786)微卫星位点的杂... 详细信息

目的建立纳克水平DNA定量方法,并探讨循环DNA检测在肿瘤诊断中的应用价值。方法对483例恶性肿瘤患者以微量基因组抽提试剂盒抽提血清DNA,以SYBRgreenⅠ荧光染色法行DNA定量;BRCA1(D17S579、D17S855)和p53(TP53,D17S786)微卫星位点的杂合性丢失检测采用聚合酶链反应结合聚丙烯酰胺凝胶电泳和银染的方法进行。同时与150例健康人血清的检测结果进行对照。结果SYBRgreenⅠ荧光染色可精确定量2～10ngDNA。483例恶性肿瘤患者血清DNA平均水平为(81.3±98.3)ng/ml,150例健康人血清DNA平均水平为(22.2±13.4)ng/ml,两者间差异有显著性(P<0.001);50例良性肿瘤患者血清DNA未见显著升高。在33例血清DNA含量增高的卵巢癌患者中,27例(81.8%)能测及BRCA1和p53微卫星标记中至少1个位点的杂合性丢失。结论循环DNA的定量有可能成为一种新的恶性肿瘤标志物。

关键词：血清DNA 循环DNA 恶性肿瘤患者 DNA定量健康人杂合性丢失人血清 SYBR 银染基因组

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粉体对分解炉内SNCR反应影响的研究

燃料化学学报 2013年第5期41卷 636-640页

作者：付世龙宋蔷仲蕾姚强清华大学热科学与动力工程教育部重点实验室北京100084

采用滴管炉反应器,针对钙基粉体对分解炉环境下SNCR反应的影响进行了研究。考察了NH3和尿素两种还原剂对不同温度(600～1 100℃)、氨氮比(0.5～2.0)和氧浓度(0.5%～5.0%)下SNCR反应的影响。实验结果表明,生料、CaO和CaCO3三种粉体都对... 详细信息

采用滴管炉反应器,针对钙基粉体对分解炉环境下SNCR反应的影响进行了研究。考察了NH3和尿素两种还原剂对不同温度(600～1 100℃)、氨氮比(0.5～2.0)和氧浓度(0.5%～5.0%)下SNCR反应的影响。实验结果表明,生料、CaO和CaCO3三种粉体都对分解炉条件下两种还原剂的SNCR反应均有抑制作用,低温下粉体的抑制作用较为明显,高温下粉体的抑制逐渐减弱。低温下生料的抑制作用强于CaCO3和CaO,主要是生料中活性杂质的催化作用;高温下CaO的抑制作用最强,之后是CaCO3和生料。随着氨氮比的增加,SNCR脱硝效率增强,粉体对脱硝效率的抑制程度基本不变。生料的最佳脱硝氧浓度为1%,而CaCO3和CaO的最佳脱硝氧浓度为2%。有粉体存在下的SNCR反应特性是气相脱硝反应与还原剂气固催化氧化反应竞争的结果。

关键词： SNCR 脱硝 NO 分解炉

Tests of the functional Coefficients in the Varing-Coefficient Cox Proportional Hazard Model

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Tests of the Functional Coefficients in the Varing-Coefficie...

CaCO_3对NH_3+NO+O_2反应体系的影响

第三十届中国控制会议

作者： LUO Xuan,CUI Guo-Zhong,LE fu-long,WANG shi-Jun Institute of Information Engineering,Zhengzhou 450001,P.R.China

＜正＞Cox proportional hazard model is one of the most celebrated models for analyzing lifetime *** exists one problem when we replace the covariate effects with varying-coefficient *** is whether this replacement is reasonable or partially *** this paper,we propose a hypothesis testing based on the asymptotic distribution of the normalized maximum deviations,for this problem,whether the parametric components are known or *** also conducted simulation studies to evaluate finite-sample properties of our proposed methods.

关键词： Varying-coefficient Time-to-event Outcome Simultaneous Confidence Band

来源： cnki会议评论

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cnki会议

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东北师大学报（自然科学版） 2011年第3期43卷 101-105页

作者：唐君实宋蔷吴兴远付世龙高攀中国石油勘探开发研究院北京100083 清华大学热能工程系北京100084

采用固床反应器系统研究了CaCO3对于SNCR脱硝效果的影响,在650℃～850℃温度范围内研究了CaCO3对于NH3氧化、NH3分解、NH3还原NO反应的作用.研究了NH3,NO和O23组分同时存在时,各催化反应的相互影响和作用大小.采用FTIR气体分析仪测量NH3... 详细信息

采用固床反应器系统研究了CaCO3对于SNCR脱硝效果的影响,在650℃～850℃温度范围内研究了CaCO3对于NH3氧化、NH3分解、NH3还原NO反应的作用.研究了NH3,NO和O23组分同时存在时,各催化反应的相互影响和作用大小.采用FTIR气体分析仪测量NH3和NO组分的浓度.结果表明:CaCO3主要对NH3分解和NH3氧化反应有催化作用,对NH3还原NO和NO分解无明显催化作用;当NH3,NO和O23组分同时存在时,主要是NH3分解反应起作用,添加O2和NO并不能明显提高NH3的转化率;CaCO3催化NH3氧化和NH3分解有相同的反应速控步,O2的加入主要是促进NH3转化产物中NO的比例.

关键词： CaCO3 SNCR 转化率选择性

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生物质合成气甲烷化催化剂研究进展

沈阳农业大学学报 2017年第4期48卷 488-496页

作者：符世龙陈应泉杨海平华中科技大学煤燃烧国家重点实验室武汉430074 华中科技大学中欧清洁与可再生能源学院武汉430074

天然气在我国未来的能源体系中占有重要的地位。以生物质为原料,将合成气通过甲烷化反应转化为天然气是将生物质能源转化为富氢、低碳能源的有效途径。本文概述了生物质合成气甲烷化催化剂的研究进展,重点阐述了CO和CO_2甲烷化催化剂不... 详细信息

天然气在我国未来的能源体系中占有重要的地位。以生物质为原料,将合成气通过甲烷化反应转化为天然气是将生物质能源转化为富氢、低碳能源的有效途径。本文概述了生物质合成气甲烷化催化剂的研究进展,重点阐述了CO和CO_2甲烷化催化剂不同的活性组分(Ni,Co,Ru等)对甲烷化反应催化效果的影响,以及不同结构的催化剂载体(Al_2O_3,ZrO2,TiO_2,SiO_2等)对催化剂活性组分的分散程度和粒径大小的影响;分析了添加不同类型的助剂(MgO,La_2O_3,CeO_2等)以及不同的制备方法(浸渍法,共沉淀法,溶胶凝胶法等)对催化剂的催化效果的影响,介绍了一些新型的催化剂载体和催化剂制备方法的特点,并指出现有甲烷化催化剂的研究目标和存在的主要问题。理想的甲烷化催化剂应当具有良好的低温催化活性和高温稳定性,具有良好的活性组分分散度和较小的粒径,同时具有良好的抗积碳性能。然而,甲烷化反应释放大量的热量导致催化剂活性组分迁移烧结,并在活性位点上积碳,从而致使催化剂钝化失活。因此,应当通过开发双金属或多金属催化剂,改进或开发具有良好孔隙结构和表面积的催化剂载体,添加不同功能的结构助剂或电子助剂,改进催化剂的制备方法等手段提高甲烷化催化剂活性组分的分散度,降低活性组分的粒径,从而提高甲烷化催化剂的催化活性,热稳定性和抗积碳性能。认为应对CO和CO_2的甲烷化反应机理,新型复合载体的制备工艺,活性组分与助剂和载体的相互作用机理,催化剂的失活机理和可再生性能等方面进行深入的研究,并以此为基础开发设计具有高催化性能的甲烷化催化剂。

关键词：生物质合成气甲烷化催化剂研究进展

Bidirectional regulation of the brain-gut-microbiota axis following traumatic brain injury

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Neural Regeneration Research 2025年第8期20卷 2153-2168页

作者： Xinyu You Lin Niu Jiafeng fu shining Ge Jiangwei shi Yanjun Zhang Pengwei Zhuang National Key Laboratory of Chinese Medicine Modernization Tianjin University of Traditional Chinese MedicineTianjinChina Haihe Laboratory of Modern Chinese Medicine Tianjin University of Traditional Chinese MedicineTianjinChina First Teaching Hospital of Tianjin University of Traditional Chinese Medicine TianjinChina National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion TianjinChina

Traumatic brain injury is a prevalent disorder of the central nervous *** addition to primary brain parenchymal damage,the enduring biological consequences of traumatic brain injury pose long-term risks for patients with traumatic brain injury;however,the underlying pathogenesis remains unclear,and effective intervention methods are *** dysfunction is a significant consequence of traumatic brain *** the most densely innervated peripheral tissue in the body,the gut possesses multiple pathways for the establishment of a bidirectional“brain-gut axis”with the central nervous *** gut harbors a vast microbial community,and alterations of the gut niche contribute to the progression of traumatic brain injury and its unfavorable prognosis through neuronal,hormonal,and immune pathways.A comprehensive understanding of microbiota-mediated peripheral neuroimmunomodulation mechanisms is needed to enhance treatment strategies for traumatic brain injury and its associated *** comprehensively reviewed alterations in the gut microecological environment following traumatic brain injury,with a specific focus on the complex biological processes of peripheral nerves,immunity,and microbes triggered by traumatic brain injury,encompassing autonomic dysfunction,neuroendocrine disturbances,peripheral immunosuppression,increased intestinal barrier permeability,compromised responses of sensory nerves to microorganisms,and potential effector nuclei in the central nervous system influenced by gut ***,we reviewed the mechanisms underlying secondary biological injury and the dynamic pathological responses that occur following injury to enhance our current understanding of how peripheral pathways impact the outcome of patients with traumatic brain *** review aimed to propose a conceptual model for future risk assessment of central nervous system-related diseases while elucidating novel insights into the bidirectional effec

关键词： traumatic brain injury brain-gut-microbiome axis gut microbiota neuroimmune immunosuppression host defense vagal afferents bacterial infection dorsal root ganglia nociception neural circuitry