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Novel GaN-based double-channel p-heterostructure field-effect transistors with a p-GaN insertion layer
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作者 牛雪锐 侯斌 +7 位作者 张濛 杨凌 武玫 张新创 贾富春 王冲 马晓华 郝跃 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第10期678-683,共6页
GaN-based p-channel heterostructure field-effect transistors(p-HFETs)face significant constraints on on-state currents compared with n-channel high electron mobility transistors.In this work,we propose a novel double ... GaN-based p-channel heterostructure field-effect transistors(p-HFETs)face significant constraints on on-state currents compared with n-channel high electron mobility transistors.In this work,we propose a novel double heterostructure which introduces an additional p-GaN insertion layer into traditional p-HFETs.The impact of the device structure on the hole densities and valence band energies of both the upper and lower channels is analyzed by using Silvaco TACD simulations,including the thickness of the upper AlGaN layer and the doping impurities and concentration in the GaN buffer layer,as well as the thickness and Mg-doping concentration in the p-GaN insertion layer.With the help of the p-GaN insertion layer,the C-doping concentration in the GaN buffer layer can be reduced,while the density of the two-dimensional hole gas in the lower channel is enhanced at the same time.This work suggests that a double heterostructure with a p-GaN insertion layer is a better approach to improve p-HFETs compared with those devices with C-doped buffer layer alone. 展开更多
关键词 GaN double-channel heterostructure field-effect transistors p-GaN insertion layer C-doped buffer layer
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Effects of Localized Interface Phonons on Heat Conductivity in Ingredient Heterogeneous Solids
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作者 武媚 时若晨 +12 位作者 亓瑞时 李跃辉 冯涛 刘秉尧 严靖园 李晓梅 刘哲彤 王涛 魏同波 刘志强 杜进隆 陈基 高鹏 《Chinese Physics Letters》 SCIE EI CAS CSCD 2023年第3期19-24,共6页
Phonons are the primary heat carriers in non-metallic solids.In compositionally heterogeneous materials,the thermal properties are believed to be mainly governed by the disrupted phonon transport due to mass disorder ... Phonons are the primary heat carriers in non-metallic solids.In compositionally heterogeneous materials,the thermal properties are believed to be mainly governed by the disrupted phonon transport due to mass disorder and strain fluctuations,while the effects of compositional fluctuation induced local phonon states are usually ignored.Here,by scanning transmission electron microscopy electron energy loss spectroscopy and sophisticated calculations,we identify the vibrational properties of ingredient-dependent interface phonon modes in Alx Ga1-x N and quantify their various contributions to the local interface thermal conductance.We demonstrate that atomic-scale compositional fluctuation has significant influence on the vibrational thermodynamic properties,highly affecting the mode ratio and vibrational amplitude of interface phonon modes and subsequently redistributing their modal contribution to the interface thermal conductance.Our work provides fundamental insights into understanding of local phonon-boundary interactions in nanoscale inhomogeneities,which reveal new opportunities for optimization of thermal properties via engineering ingredient distribution. 展开更多
关键词 INTERFACE PHONON thermal
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聚(丙烯酸-co-2-丙烯酰胺基-2-甲基-1-丙烷磺酸)/凹凸棒石复合高吸水树脂的制备及溶胀动力学 被引量:5
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作者 吴梅 祁晓华 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2019年第5期117-122,共6页
以N,N’-亚甲基双丙烯酰胺和三羟甲基丙烷三缩水甘油醚为交联剂,利用部分中和的丙烯酸、2-丙烯酰胺基-2-甲基-1-丙烷磺酸和凹凸棒石为原料制备了高吸水树脂,并采用丙三醇和硅酸钠进行表面交联及与硫酸铝和碳酸钠无机盐共混技术对高吸水... 以N,N’-亚甲基双丙烯酰胺和三羟甲基丙烷三缩水甘油醚为交联剂,利用部分中和的丙烯酸、2-丙烯酰胺基-2-甲基-1-丙烷磺酸和凹凸棒石为原料制备了高吸水树脂,并采用丙三醇和硅酸钠进行表面交联及与硫酸铝和碳酸钠无机盐共混技术对高吸水树脂进行了后处理,对高吸水树脂的结构进行了表征,分析了该树脂有高的吸水速率和吸水倍数的原因,考察了溶液的pH、离子种类及离子强度对树脂溶胀动力学的影响。结果表明,溶液的pH对树脂的溶胀动力学有影响,在不同pH的NaCl溶液中都表现出supercaseⅡ扩散行为。高价阳离子溶液对树脂溶胀动力学影响显著,出现了退溶胀现象,采用Díez-Pe?a的模型对退溶胀现象进行了定量分析,与实验数据吻合度较好。阴离子对树脂溶胀动力学影响不大,在不同阴离子溶液中树脂的扩散行为符合supercaseⅡ扩散类型。 展开更多
关键词 高吸水树脂 溶胀动力学 凹凸棒石 2-丙烯酰胺基-2-甲基-1-丙烷磺酸
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Evaluation of internal and shell stiffness in the differential diagnosis of breast non-mass lesions by shear wave elastography 被引量:6
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作者 Ping Xu mei wu +3 位作者 Min Yang Juan Xiao Zheng-Min Ruan Lan-Ying wu 《World Journal of Clinical Cases》 SCIE 2020年第12期2510-2519,共10页
BACKGROUND The diagnostic specificity of conventional ultrasound for breast non-mass lesions(NMLs)is low at approximately 21%-43%.Shear wave elastography(SWE)can distinguish benign from malignant lesions by evaluating... BACKGROUND The diagnostic specificity of conventional ultrasound for breast non-mass lesions(NMLs)is low at approximately 21%-43%.Shear wave elastography(SWE)can distinguish benign from malignant lesions by evaluating the internal and peripheral stiffness.SWE has good reproducibility and high diagnostic efficacy.However,there are very few independent studies on the diagnostic value of SWE in breast NMLs.AIM To determine the value of SWE in the differential diagnosis of breast NMLs.METHODS This study enrolled a total of 118 patients with breast NMLs who underwent SWE examinations in the Beijing Shijitan Hospital Affiliated to Capital Medical University and The Second Hospital of Shandong University from January 2019 to January 2020.The internal elastic parameters of the lesions were recorded,including maximum(Emax),mean(Emean)and minimum elastic values and the standard deviation.The following peripheral parameters were noted:Presence of a“stiff rim”sign;Emax,and Emean elasticity values within 1 mm,1.5 mm,2 mm,2.5 mm and 3 mm from the edge of NMLs.The receiver operating characteristic curve of each parameter was drawn,and the areas under the curve were calculated.RESULTS Emax,Emean and elastic values,and the standard deviation of the internal elastic values in malignant NMLs were significantly higher than those in benign NMLs(P<0.05).The percentage with the“stiff rim”sign in malignant NMLs was significantly higher than that in the benign group(P<0.05),and Emax and Emean at the shell of 1 mm,1.5 mm,2 mm,2.5 mm and 3 mm in the malignant group were all higher than those in the benign group(P<0.05).Of the surrounding elasticity values,Emax of the shell at 2.5 mm in malignant NMLs had maximum areas under the curve of 0.900,and the corresponding sensitivity and specificity were 94.57%and 85.86%,respectively.CONCLUSION The“stiff rim”sign and multiple quantitative elastic values within and around the lesion had good diagnostic performance in the differential diagnosis of breast NMLs.Emax in peripheral tissue had better diagnostic efficiency than other parameters. 展开更多
关键词 Breast tumor Shear wave elastography Non-mass lesions Stiff rim sign Ultrasound Diagnosis
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Sonographic features of umbilical vein recanalization for a Rex shunt on cavernous transformation of portal vein in children 被引量:2
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作者 Yu-Qing Zhang Qing Wang +6 位作者 mei wu Ya Li Xiu-Liang Wei Fei-Xue Zhang Yan Li Guang-Rui Shao Juan Xiao 《World Journal of Clinical Cases》 SCIE 2020年第22期5555-5563,共9页
BACKGROUND The Rex shunt was widely used as the preferred surgical approach for cavernous transformation of the portal vein(CTPV)in children that creates a bypass between the superior mesenteric vein and the intrahepa... BACKGROUND The Rex shunt was widely used as the preferred surgical approach for cavernous transformation of the portal vein(CTPV)in children that creates a bypass between the superior mesenteric vein and the intrahepatic left portal vein(LPV).This procedure can relieve portal hypertension and restore physiological hepatopetal flow.However,the modified procedure is technically demanding because it is difficult to make an end-to-end anastomosis of a bypass to a hypoplastic LPV.Many studies reported using a recanalized umbilical vein as a conduit to resolve this problem.However,the feasibility of umbilical vein recanalization for a Rex shunt has not been fully investigated.AIM To investigate the efficacy of a recanalized umbilical vein as a conduit for a Rex shunt on CTPV in children by ultrasonography.METHODS A total of 47 children who were diagnosed with CTPV with prehepatic portal hypertension in the Second Hospital,Cheeloo College of Medicine,Shandong University,were enrolled in this study.Fifteen children received a recanalized umbilical vein as a conduit for a Rex shunt surgery and were enrolled in group I.Thirty-two children received the classic Rex shunt surgery and were enrolled in group II.The sonographic features of the two groups related to intraoperative and postoperative variation in terms of bypass vessel and the LPV were compared.RESULTS The patency rate of group I(60.0%,9/15)was significantly lower than that of group II(87.5%,28/32)7 d after(on the 8th d)operation(P<0.05).After clinical anticoagulation treatment for 3 mo,there was no significant difference in the patency rate between group I(86.7%,13/15)and group II(90.6%,29/32)(P>0.05).Moreover,3 mo after(at the beginning of the 4th mo)surgery,the inner diameter significantly widened and flow velocity notably increased for the bypass vessels and the sagittal part of the LPV compared to intraoperative values in both shunt groups(P<0.05).However,there was no significant difference between the two surgical groups 3 mo after surgery(P>0.05).CONCLUSION For children with hypoplastic LPV in the Rex recessus,using a recanalized umbilical vein as a conduit for a Rex shunt may be an effective procedure for CTPV treatment. 展开更多
关键词 Cavernous transformation of the portal vein Rex shunt RECANALIZATION Umbilical vein ULTRASONOGRAPHY
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Association of neuregulin-1 with schizophrenia 被引量:1
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作者 mei wu Jiachun Lu 《Neural Regeneration Research》 SCIE CAS CSCD 2008年第2期229-232,共4页
BACKGROUND: Recent studies have paid much attention to the newly found neuregulin-1, which might be closely linked to the molecular genetics of schizophrenia. OBJECTIVE: To investigate the association of neuregulin-... BACKGROUND: Recent studies have paid much attention to the newly found neuregulin-1, which might be closely linked to the molecular genetics of schizophrenia. OBJECTIVE: To investigate the association of neuregulin-related genes with schizophrenia, and to summarize the advancements in this current research. RETRIEVAL STRATEGY: Using the terms "neuregulins, gene, schizophrenia", we retrieved articles published from January 2000 to June 2007 from http://www.ncbi.nlm.gov, http://www.elsevier.lib.tsinghua.edu.cn, and http://www.cjfd.cnki.net to identify studies addressing the association of neuregulin-related genes to schizophrenia. At the same time, we searched more than 10 medical journals by hand. The languages were limited to English and Chinese. Forty-two manuscripts were obtained and were firstly screened. Inclusion criteria: studies on neuregulins, schizophrenia, neuregulin-1, and the pathogenesis of schizophrenia, including randomized, blinded, and other original studies. Exclusion criteria: studies not related to schizophrenia, or repetitive studies. LITERATURE EVALUATION: The included 42 manuscripts were sorted. Twenty-one were selected as references for this article: fourteen were basic studies, and the remaining articles were case-controlled studies or other. DATA SYNTHESIS: Neuregulins are primarily expressed in the nervous system and heart, and limited expression is also seen in other tissues.. These proteins transmit signals among certain cells and play an important role in normal development of the nervous system. Neuregulin-1 is a typical neuregulin-related gene. Neuregulin genes are closely related to glutamatergic, GABAergic, and dopaminergic neurons. CONCLUSION: Neuregulin-related genes, such as neuregulin-1, are important and promising candidate genes for studying schizophrenia disease. Their roles in the onset of schizophrenia, neuregulin-related gene expression products, and correlations of ErbB receptor to schizophrenia symptoms need to be further investigated. Further studies of neuregulin-1 will hopefully provide powerful evidence for understanding the pathogenesis of schizophrenia. 展开更多
关键词 NEUREGULINS SCHIZOPHRENIA candidate gene
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Probing Lattice Vibrations at SiO_2/Si Surface and Interface with Nanometer Resolution 被引量:2
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作者 李跃辉 武媚 +7 位作者 亓瑞时 李宁 孙元伟 施成龙 朱学涛 郭建东 俞大鹏 高鹏 《Chinese Physics Letters》 SCIE CAS CSCD 2019年第2期40-48,共9页
Recent advances in monochromatic aberration corrected electron microscopy make it possible to detect the lattice vibrations with both high-energy resolution and high spatial resolution. Here, we use sub-10 meV electro... Recent advances in monochromatic aberration corrected electron microscopy make it possible to detect the lattice vibrations with both high-energy resolution and high spatial resolution. Here, we use sub-10 meV electron energy loss spectroscopy to investigate the local vibrational properties of the SiO_2/Si surface and interface. The energy of the surface mode is thickness dependent, showing a blue shift as z-thickness(parallel to the fast electron beam)of SiO_2 film increases, while the energy of the bulk mode and the interface mode keeps constant. The intensity of the surface mode is well-described by a Bessel function of the second kind. The mechanism of the observed spatially dependent vibrational behavior is discussed and compared with dielectric response theory analysis. Our nanometer scale measurements provide useful information on the bonding conditions at the surface and interface. 展开更多
关键词 SIO
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Negative bias-induced threshold voltage instability and zener/interface trapping mechanism in GaN-based MIS-HEMTs
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作者 朱青 马晓华 +6 位作者 陈怡霖 侯斌 祝杰杰 张濛 武玫 杨凌 郝跃 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第4期445-450,共6页
We investigate the instability of threshold voltage in D-mode MIS-HEMT with in-situ SiN as gate dielectric under different negative gate stresses.The complex non-monotonic evolution of threshold voltage under the nega... We investigate the instability of threshold voltage in D-mode MIS-HEMT with in-situ SiN as gate dielectric under different negative gate stresses.The complex non-monotonic evolution of threshold voltage under the negative stress and during the recovery process is induced by the combination effect of two mechanisms.The effect of trapping behavior of interface state at SiN/AlGaN interface and the effect of zener traps in AlGaN barrier layer on the threshold voltage instability are opposite to each other.The threshold voltage shifts negatively under the negative stress due to the detrapping of the electrons at SiN/AlGaN interface,and shifts positively due to zener trapping in AlGaN barrier layer.As the stress is removed,the threshold voltage shifts positively for the retrapping of interface states and negatively for the thermal detrapping in AlGaN.However,it is the trapping behavior in the AlGaN rather than the interface state that results in the change of transconductance in the D-mode MIS-HEMT. 展开更多
关键词 threshold voltage INSTABILITY interface state zener trap MIS-HEMT
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Improved device performance of recessed-gate AlGaN/GaN HEMTs by using in-situ N_(2)O radical treatment
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作者 张新创 武玫 +8 位作者 侯斌 牛雪锐 芦浩 贾富春 张濛 杜佳乐 杨凌 马晓华 郝跃 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第5期609-614,共6页
The N_(2)O radicals in-situ treatment on gate region has been employed to improve device performance of recessedgate Al Ga N/Ga N high-electron-mobility transistors(HEMTs).The samples after gate recess etching were tr... The N_(2)O radicals in-situ treatment on gate region has been employed to improve device performance of recessedgate Al Ga N/Ga N high-electron-mobility transistors(HEMTs).The samples after gate recess etching were treated by N_(2)O radicals without physical bombardment.After in-situ treatment(IST)processing,the gate leakage currents decreased by more than one order of magnitude compared to the sample without IST.The fabricated HEMTs with the IST process show a low reverse gate current of 10;A/mm,high on/off current ratio of 108,and high f_(T)×L_(g)of 13.44 GHz·μm.A transmission electron microscope(TEM)imaging illustrates an oxide layer with a thickness of 1.8 nm exists at the AlGaN surface.X-ray photoelectron spectroscopy(XPS)measurement shows that the content of the Al-O and Ga-O bonds elevated after IST,indicating that the Al-N and Ga-N bonds on the AlGaN surface were broken and meanwhile the Al-O and Ga-O bonds formed.The oxide formed by a chemical reaction between radicals and the surface of the AlGaN barrier layer is responsible for improved device characteristics. 展开更多
关键词 ALGAN/GAN high-electron-mobility transistors low gate leakage radio frequency radical treatment
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High power-added-efficiency AlGaN/GaN HEMTs fabricated by atomic level controlled etching
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作者 张新创 侯斌 +8 位作者 贾富春 芦浩 牛雪锐 武玫 张濛 杜佳乐 杨凌 马晓华 郝跃 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第2期552-557,共6页
An atomic-level controlled etching(ACE)technology is invstigated for the fabrication of recessed gate AlGaN/GaN high-electron-mobility transistors(HEMTs)with high power added efficiency.We compare the recessed gate HE... An atomic-level controlled etching(ACE)technology is invstigated for the fabrication of recessed gate AlGaN/GaN high-electron-mobility transistors(HEMTs)with high power added efficiency.We compare the recessed gate HEMTs with conventional etching(CE)based chlorine,Cl_(2)-only ACE and BCl^(3)/Cl_(2)ACE,respectively.The mixed radicals of BCl_(3)/Cl_(2)were used as the active reactants in the step of chemical modification.For ensuring precise and controllable etching depth and low etching damage,the kinetic energy of argon ions was accurately controlled.These argon ions were used precisely to remove the chemical modified surface atomic layer.Compared to the HEMTs with CE,the characteristics of devices fabricated by ACE are significantly improved,which benefits from significant reduction of etching damage.For BCl_(3)/Cl_(2)ACE recessed HEMTs,the load pull test at 17 GHz shows a high power added efficiency(PAE)of 59.8%with an output power density of 1.6 W/mm at Vd=10 V,and a peak PAE of 44.8%with an output power density of 3.2 W/mm at Vd=20 V in a continuous-wave mode. 展开更多
关键词 AlGaN/GaN HEMTs recess etching low damage high power added efficiency
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Trap analysis of composite 2D-3D channel in AlGaN/GaN/graded-AlGaN:Si/GaN:C multi-heterostructure at different temperatures
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作者 胡晟 杨凌 +12 位作者 宓珉瀚 侯斌 刘晟 张濛 武玫 朱青 武盛 卢阳 祝杰杰 周小伟 吕玲 马晓华 郝跃 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第8期451-456,共6页
The graded AlGaN:Si back barrier can form the majority of three-dimensional electron gases(3DEGs)at the GaN/graded AlGaN:Si heterostructure and create a composite two-dimensional(2D)-three-dimensional(3D)channel in Al... The graded AlGaN:Si back barrier can form the majority of three-dimensional electron gases(3DEGs)at the GaN/graded AlGaN:Si heterostructure and create a composite two-dimensional(2D)-three-dimensional(3D)channel in AlGaN/GaN/graded-AlGaN:Si/GaN:C heterostructure(DH:Si/C).Frequency-dependent capacitances and conductance are measured to investigate the characteristics of the multi-temperature trap states of in DH:Si/C and AlGaN/GaN/GaN:C heterostructure(SH:C).There are fast,medium,and slow trap states in DH:Si/C,while only medium trap states exist in SH:C.The time constant/trap density for medium trap state in SH:C heterostructure are(11μs-17.7μs)/(1.1×10^13 cm^-2·eV^-1-3.9×10^13 cm^-2·eV^-1)and(8.7μs-14.1μs)/(0.7×10^13 cm^-2·eV^-1-1.9×10^13 cm^-2·eV^-1)at 300 K and 500 K respectively.The time constant/trap density for fast,medium,and slow trap states in DH:Si/C heterostructure are(4.2μs-7.7μs)/(1.5×10^13 cm^-2·eV^-1-3.2×10^13 cm^-2·eV^-1),(6.8μs-11.8μs)/(0.8×10^13 cm^-2·eV^-1-2.8×10^13 cm^-2·eV^-1),(30.1μs-151μs)/(7.5×10^12 cm^-2·eV^-1-7.8×10^12 cm^-2·eV^-1)at 300 K and(3.5μs-6.5μs)/(0.9×10^13 cm^-2·eV^-1-1.8×10^13 cm^-2·eV^-1),(4.9μs-9.4μs)/(0.6×10^13 cm^-2·eV^-1-1.7×10^13 cm^-2·eV^-1),(20.6μs-61.9μs)/(3.2×10^12 cm^-2·eV^-1-3.5×10^12 cm^-2·eV^-1)at 500 K,respectively.The DH:Si/C structure can effectively reduce the density of medium trap states compared with SH:C structure. 展开更多
关键词 AlGaN/GaN HEMT multi-heterostructure composite 2D-3D channel multi-temperature trap states
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Timing analysis of the black hole candidate EXO 1846–031 with Insight-HXMT monitoring
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作者 He-Xin Liu Yue Huang +118 位作者 Guang-Cheng Xiao Qing-Cui Bu Jin-Lu Qu Shu Zhang Shuang-Nan Zhang Shu-mei Jia Fang-Jun Lu Xiang Ma Lian Tao Wei Zhang Li Chen Li-Ming Song Ti-Pei Li Yu-Peng Xu Xue-Lei Cao Yong Chen Cong-Zhan Liu Ce Cai Zhi Chang Gang Chen Tian-Xiang Chen Yi-Bao Chen Yu-Peng Chen Wei Cui Wei-Wei Cui Jing-Kang Deng Yong-Wei Dong Yuan-Yuan Du Min-Xue Fu Guan-Hua Gao He Gao Min Gao Ming-Yu Ge Yu-Dong Gu Ju Guan Cheng-Cheng Guo Da-Wei Han Jia Huo Lu-Hua Jiang Wei-Chun Jiang Jing Jin Yong-Jie Jin Ling-Da Kong Bing Li Cheng-Kui Li Gang Li Mao-Shun Li Wei Li Xian Li Xiao-Bo Li Xu-Fang Li Yang-Guo Li Zheng-Wei Li Xiao-Hua Liang Jing-Yuan Liao Bai-Sheng Liu Guo-Qing Liu Hong-Wei Liu Xiao-Jing Liu Yi-Nong Liu Bo Lu Xue-Feng Lu Qi Luo Tao Luo Bin Meng Yi Nang Jian-Yin Nie Ge Ou Na Sai Ren-Cheng Shang Xin-Ying Song Liang Sun Ying Tan You-Li Tuo Chen Wang Guo-Feng Wang Juan Wang Ling-Jun Wang Weng-Shuai Wang Yu-Sa Wang Xiang-Yang Wen Bai-Yang wu Bo-Bing wu mei wu Shuo Xiao Shao-Lin Xiong He Xu Jia-Wei Yang Sheng Yang Yan-Ji Yang Yi-Jung Yang Qi-Bin Yi Qian-Qing Yin Yuan You Ai-mei Zhang Cheng-Mo Zhang Fan Zhang Hong-mei Zhang Juan Zhang Tong Zhang Wan-Chang Zhang Wen-Zhao Zhang Yi Zhang Yi-Fei Zhang Yong-Jie Zhang Yuan-Hang Zhang Yue Zhang Zhao Zhang Zhi Zhang Zi-Liang Zhang Hai-Sheng Zhao Xiao-Fan Zhao Shi-Jie Zheng Yao-Guang Zheng Deng-Ke Zhou Jian-Feng Zhou Yu-Xuan Zhu Ren-Lin Zhuang Yue Zhu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2021年第3期193-204,共12页
We present the observational results from a detailed timing analysis of the black hole candidate EXO 1846-031 during its outburst in 2019 with the observations of Insight-HXMT,NICER and MAXI.This outburst can be class... We present the observational results from a detailed timing analysis of the black hole candidate EXO 1846-031 during its outburst in 2019 with the observations of Insight-HXMT,NICER and MAXI.This outburst can be classified roughly into four different states.Type-C quasi-periodic oscillations(QPOs)observed by NICER(about 0.1-6 Hz)and Insight-HXMT(about 0.7-8 Hz)are also reported in this work.Meanwhile,we study various physical quantities related to QPO frequency.The QPO rms-frequency relationship in the energy band 1-10 keV indicates that there is a turning pointing in frequency around2 Hz,which is similar to that of GRS 1915+105.A possible hypothesis for the relationship above may be related to the inclination of the source,which may require a high inclination to explain it.The relationships between QPO frequency and QPO rms,hardness,total fractional rms and count rate have also been found in other transient sources,which can indicate that the origin of type-C QPOs is non-thermal. 展开更多
关键词 X-ray binaries black hole candidate QPO EXO 1846–031
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LPS增强NNK介导的抑制腹腔巨噬细胞中NF-κB表达的作用(英文)
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作者 Bin Li mei wu Xiaoping Liu 《The Chinese-German Journal of Clinical Oncology》 CAS 2014年第7期332-336,共5页
Objective: The aim of the study was to investigate the effect of lipopolysaccharide(LPS) on the expression of nuclear factor kappa B(NF-κB) in 4-(methylitrosamino)-1-(3-pyridyl)-1-butanone(NNK)-mediated primary mouse... Objective: The aim of the study was to investigate the effect of lipopolysaccharide(LPS) on the expression of nuclear factor kappa B(NF-κB) in 4-(methylitrosamino)-1-(3-pyridyl)-1-butanone(NNK)-mediated primary mouse peritoneal macrophages in vitro. Methods: The activity of peritoneal macrophages treated with different concentrations of LPS was detected by MTT assay in rider to find the optimal concentration. Peritoneal macrophages were also treated with NNK(100–500 μM), with or without LPS for 9 h. The expression of NF-κB was demonstrated via immunocytochemistry(ICC) and Westernblot, respectively. Results: The concentration of LPS at 25 μg/mL was found to be the optimal concentration to improve the activity of peritoneal macrophages(P < 0.01). Simultaneously, LPS(25 μg/mL) increased the expression of NF-κB in both the nucleus and cytoplasm and facilitated transfer of NF-κB to the nucleus. NNK treatment significantly inhibited the expression of NF-κB in a concentration-dependent manner, among the LPS-stimulated or unstimulated peritoneal macrophages, especially when cotreated with LPS(25 μg/mL, P < 0.01). Furthermore, NNK treatment(500 μM) with LPS yielded a significant decrease in NF-κB translocation to nucleus and inhibited the expression of NF-κB(P < 0.005). Conclusion: LPS enhances the suppression of NF-κB expression in NNK-mediated mouse peritoneal macrophages, which may provide a theoretical basis for the inhibition of cancer. 展开更多
关键词 腹腔巨噬细胞 脂多糖 介导 浓度依赖性 核因子κB 免疫细胞化学 LPS 细胞核
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Textural differences based on apparent diffusion coefficient maps for discriminating pT3 subclasses of rectal adenocarcinoma
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作者 Zhi-Hua Lu Kai-Jian Xia +2 位作者 Heng Jiang Jian-Long Jiang mei wu 《World Journal of Clinical Cases》 SCIE 2021年第24期6987-6998,共12页
BACKGROUND The accuracy of discriminating pT3a from pT3b-c rectal cancer using highresolution magnetic resonance imaging(MRI)remains unsatisfactory,although texture analysis(TA)could improve such discrimination.AIM To... BACKGROUND The accuracy of discriminating pT3a from pT3b-c rectal cancer using highresolution magnetic resonance imaging(MRI)remains unsatisfactory,although texture analysis(TA)could improve such discrimination.AIM To investigate the value of TA on apparent diffusion coefficient(ADC)maps in differentiating pT3a rectal adenocarcinomas from pT3b-c tumors.METHODS This was a case-control study of 59 patients with pT3 rectal adenocarcinoma,who underwent diffusion-weighted imaging(DWI)between October 2016 and December 2018.The inclusion criteria were:(1)Proven pT3 rectal adenocarcinoma;(2)Primary MRI including high-resolution T2-weighted image(T2WI)and DWI;and(3)Availability of pathological reports for surgical specimens.The exclusion criteria were:(1)Poor image quality;(2)Preoperative chemoradiation therapy;and(3)A different pathological type.First-order(ADC values,skewness,kurtosis,and uniformity)and second-order(energy,entropy,inertia,and correlation)texture features were derived from whole-lesion ADC maps.Receiver operating characteristic curves were used to determine the diagnostic value for pT3b-c tumors.RESULTS The final study population consisted of 59 patients(34 men and 25 women),with a median age of 66 years(range,41-85 years).Thirty patients had pT3a,24 had pT3b,and five had pT3c.Among the ADC first-order textural differences between pT3a and pT3b-c rectal adenocarcinomas,only skewness was significantly lower in the pT3a tumors than in pT3b-c tumors.Among the ADC second-order textural differences,energy and entropy were significantly different between pT3a and pT3b-c rectal adenocarcinomas.For differentiating pT3a rectal adenocarcinomas from pT3b-c tumors,the areas under the curves(AUCs)of skewness,energy,and entropy were 0.686,0.657,and 0.747,respectively.Logistic regression analysis of all three features yielded a greater AUC(0.775)in differentiating pT3a rectal adenocarcinomas from pT3b-c tumors(69.0%sensitivity and 83.3%specificity).CONCLUSION TA features derived from ADC maps might potentially differentiate pT3a rectal adenocarcinomas from pT3b-c tumors. 展开更多
关键词 Diffusion-weighted imaging Apparent diffusion coefficient Rectal cancer Cancer stage Texture analysis case-control study
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Research Progress on Rapid Breeding Technology of Anoectochilus roxburghii Seedlings
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作者 Qinger JIANG Xiaojing TAN +3 位作者 Qiuli wu mei wu Xiaoxia SHEN Zhonghua WANG 《Medicinal Plant》 CAS 2018年第1期39-42,46,共5页
As a traditional precious Chinese herbal medicine,Anoectochilus roxburghii has the cooling and detoxifying effects,and can nourish yin to reduce pathogenic fire,and has anti-inflammatory and analgesic effects. In this... As a traditional precious Chinese herbal medicine,Anoectochilus roxburghii has the cooling and detoxifying effects,and can nourish yin to reduce pathogenic fire,and has anti-inflammatory and analgesic effects. In this paper,we summarized the research progress in detail about the biological characteristics,resource distribution,composition,medicinal value and rapid seedling breeding technology concerning the rare Chinese herbal medicine A. roxburghii,in order to provide a reference for the in-depth study and rational development and utilization of A.roxburghii. 展开更多
关键词 Anoectochilus roxburghii Germplasm resources Medicinal value Rapid breeding technology Research progress
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Discussion on Construction of Henan Cultural Products about Geotourism
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作者 mei wu Tianyi ZHANG 《Asian Agricultural Research》 2013年第3期106-108,112,共4页
With the construction and development of Geoparks,geo-tourism culture is brought into being. Based on the significance of geotourism cultural product system,this article summarizes the natural heritage properties and ... With the construction and development of Geoparks,geo-tourism culture is brought into being. Based on the significance of geotourism cultural product system,this article summarizes the natural heritage properties and scientific cultural value of Henan geological heritage resources and landscape resources,points out the various risks in construction of geo-tourism culture,such as the uncertainty of geo-tourism resources and their distribution areas,the uncertainty of the Geoparks building policies from governments,etc. ,and finally proposes some constructive suggestions and measures to avoid these risks. 展开更多
关键词 GEOPARK Geo-tourism RESOURCES TOURISM culture Risk
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基于《黄帝内经》“脾为之使”理论从肺脾辨治特发性肺纤维化
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作者 邓祥丽 邵梅 +2 位作者 杨梅 吴梅 陈丽娟 《国际中医中药杂志》 2024年第7期821-825,共5页
特发性肺纤维化(IPF)是慢性虚损性肺病, 病因不明, 证候复杂, 病情迁延难愈。基于《黄帝内经》"脾为之使"理论, 阐释"脾为之使"的中医含义, 脾与其他四脏间的关系, 尤其强调脾与肺之间的关系。认为IPF发病起因为肺... 特发性肺纤维化(IPF)是慢性虚损性肺病, 病因不明, 证候复杂, 病情迁延难愈。基于《黄帝内经》"脾为之使"理论, 阐释"脾为之使"的中医含义, 脾与其他四脏间的关系, 尤其强调脾与肺之间的关系。认为IPF发病起因为肺脾气虚, 失于固卫, 邪犯营卫;气虚郁而化热伤阴, 久则血伤入络, 累及于阳。病变过程显现出由气入血、由经至络的变化, 最终导致气血、阴阳失衡, 痰瘀胶结, 痹阻肺络, 虚实夹杂, 缠绵难愈。治疗上以"脾为之使"为中心, 健肺脾之气、养肺胃之阴顾护其本, 辨证施治, 适时辅以活血、化痰、温阳、通络之法, 为丰富中医辨治IPF提供新思路。 展开更多
关键词 特发性肺纤维化 肺痿 肺痹 脾为之使 肺脾
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A Topology-Matching Spike Protein-Capping Tetrahedral DNA Nanocrown for SARS-CoV-2 Neutralization
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作者 Jingran Chen Shuxin Xu +8 位作者 Qing Ye Hang Chi Ying Li mei wu Baochao Fan Zhanchen Guo Cheng-Feng Qin Bin Li Zhen Liu 《CCS Chemistry》 CSCD 2023年第6期1372-1385,共14页
The constantly mutating severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)poses great risk of efficacy loss to the present neutralizing therapeutics.Thus,it is urgently needed to develop versatile strategies ... The constantly mutating severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)poses great risk of efficacy loss to the present neutralizing therapeutics.Thus,it is urgently needed to develop versatile strategies that enable rapid design and engineering of potent neutralizing therapeutics for newly emerging variants.Herein,we present an unprecedented DNA nanocrown that can topologically match and multivalently bind the S-trimer of SARS-CoV-2 and thereby inhibit its infection to host cells.A neutralizing aptamer binding the N-terminal domain(NTD)supersite of the S protein was first screened and identified.It was further elaborately engineered onto the best fitting tetrahedral DNA nanostructure to form a spike protein-capping nanocrown,which can effectively block not only wild-type(WT)SARS-CoV-2 pseudovirus,but also several important mutants including D614G,N501Y,andΔ69–70.Significantly,it can evidently diminish the RNA copies of authentic WT SARS-CoV-2 in host cells by 4.6 orders of magnitude.Therefore,utilizing the aptamer selection method and the dedicated engineering route,our topology-matching DNA framework provides a versatile platform for SARS-CoV-2 inhibition and has the potential to be facilely expanded to newly emerging variants and other fatal coronaviruses. 展开更多
关键词 aptamer topology-matching DNA framework SARS-CoV-2 neutralization therapy N-terminal domain supersite
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垂直腔面发射激光器的混沌同步恢复时间研究 被引量:6
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作者 吴梅 王龙生 +1 位作者 王云才 王安帮 《激光与光电子学进展》 CSCD 北大核心 2020年第21期134-141,共8页
利用半导体激光器的混沌同步有望实现高速物理随机密钥分发,然而激光器的混沌同步恢复时间限制密钥分发的速率。为此数值研究垂直腔面发射激光器(VCSEL)在开环注入锁定同步系统中,影响混沌同步恢复时间的因素。模拟结果表明,可以通过三... 利用半导体激光器的混沌同步有望实现高速物理随机密钥分发,然而激光器的混沌同步恢复时间限制密钥分发的速率。为此数值研究垂直腔面发射激光器(VCSEL)在开环注入锁定同步系统中,影响混沌同步恢复时间的因素。模拟结果表明,可以通过三种途径缩短混沌同步恢复时间,增加激光器的偏置电流、微分增益系数,或减小光子、载流子寿命来缩短弛豫振荡周期;减小线宽增强因子来减小激光混沌的复杂度;增加注入强度、减小频率失谐来实现强注入锁定。研究结果对提高基于混沌激光同步的密钥分发速率具有理论借鉴的意义。 展开更多
关键词 光通信 混沌保密通信 密钥分发 半导体激光器 混沌同步恢复时间
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Insight-HXMT observations of the first binary neutron star merger GW170817 被引量:19
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作者 TiPei Li ShaoLin Xiong +107 位作者 ShuangNan Zhang FangJun Lu LiMing Song XueLei Cao Zhi Chang Gang Chen Li Chen TianXiang Chen Yong Chen YiBao Chen YuPeng Chen Wei Cui WeiWei Cui JingKang Deng YongWei Dong YuanYuan Du MinXue Fu GuanHua Gao He Gao Min Gao MingYu Ge YuDong Gu Ju Guan ChengCheng Guo DaWei Han Wei Hu Yue Huang Jia Huo Shumei Jia LuHua Jiang WeiChun Jiang Jing Jin YongJie Jin Bing Li ChengKui Li Gang Li MaoShun Li Wei Li Xian Li XiaoBo Li XuFang Li YanGuo Li ZiJian Li ZhengWei Li XiaoHua Liang JinYuan Liao CongZhan Liu GuoQing Liu HongWei Liu ShaoZhen Liu XiaoJing Liu Yuan Liu YiNong Liu Bo Lu XueFeng Lu Tao Luo Xiang Ma Bin Meng Yi Nang JianYin Nie Ge OU JinLu Qu Na Sai Liang Sun Yin Tan Lian Tao WenHui Tao YouLi Tuo GuoFeng Wang HuanYu Wang Juan Wang WenShuai Wang YuSa Wang XiangYang Wen BoBing wu mei wu GuangCheng Xiao He Xu YuPeng Xu LinLi Yan JiaWei Yang Sheng Yang YanJi Yang Aimei Zhang ChunLei Zhang ChengMo Zhang Fan Zhang Hongmei Zhang Juan Zhang Qiang Zhang Shu Zhang Tong Zhang Wei Zhang WanChang Zhang WenZhao Zhang Yi Zhang Yue Zhang YiFei Zhang YongJie Zhang Zhao Zhang ZiLiang Zhang HaiSheng Zhao JianLing Zhao XiaoFan Zhao ShiJie Zheng Yue Zhu YuXuan Zhu ChangLin Zou 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2018年第3期26-33,共8页
Finding the electromagnetic(EM) counterpart of binary compact star merger, especially the binary neutron star(BNS) merger,is critically important for gravitational wave(GW) astronomy, cosmology and fundamental physics... Finding the electromagnetic(EM) counterpart of binary compact star merger, especially the binary neutron star(BNS) merger,is critically important for gravitational wave(GW) astronomy, cosmology and fundamental physics. On Aug. 17, 2017,Advanced LIGO and Fermi/GBM independently triggered the first BNS merger, GW170817, and its high energy EM counterpart,GRB 170817 A, respectively, resulting in a global observation campaign covering gamma-ray, X-ray, UV, optical, IR, radio as well as neutrinos. The High Energy X-ray telescope(HE) onboard Insight-HXMT(Hard X-ray Modulation Telescope) is the unique high-energy gamma-ray telescope that monitored the entire GW localization area and especially the optical counterpart(SSS17 a/AT2017 gfo) with very large collection area(~1000 cm^2) and microsecond time resolution in 0.2-5 MeV. In addition,Insight-HXMT quickly implemented a Target of Opportunity(ToO) observation to scan the GW localization area for potential X-ray emission from the GW source. Although Insight-HXMT did not detect any significant high energy(0.2-5 MeV) radiation from GW170817, its observation helped to confirm the unexpected weak and soft nature of GRB 170817 A. Meanwhile,Insight-HXMT/HE provides one of the most stringent constraints(~10^(-7) to 10^(-6) erg/cm^2/s) for both GRB170817 A and any other possible precursor or extended emissions in 0.2-5 MeV, which help us to better understand the properties of EM radiation from this BNS merger. Therefore the observation of Insight-HXMT constitutes an important chapter in the full context of multi-wavelength and multi-messenger observation of this historical GW event. 展开更多
关键词 二进制 中子星 兼并 gamma 检查调整 时间分辨率 望远镜 快速实现
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