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Diagnostic value of conventional endoscopic ultrasound for lymph node metastasis in upper gastrointestinal neoplasia:A metaanalysis 被引量:1
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作者 Cong Chen Ya-Lan Song +3 位作者 zhen-yu wu Jing Chen Yao Zhang Lei Chen 《World Journal of Gastroenterology》 SCIE CAS 2023年第30期4685-4700,共16页
BACKGROUND Upper gastrointestinal neoplasia mainly includes esophageal cancer and gastric cancer,both of which have high morbidity and mortality.Lymph node metastasis(LNM),as the most common metastasis mode of both di... BACKGROUND Upper gastrointestinal neoplasia mainly includes esophageal cancer and gastric cancer,both of which have high morbidity and mortality.Lymph node metastasis(LNM),as the most common metastasis mode of both diseases,is an important factor affecting tumor stage,treatment strategy and clinical prognosis.As a new fusion technology,endoscopic ultrasound(EUS)is becoming increasingly used in the diagnosis and treatment of digestive system diseases,but its use in detecting LNM in clinical practice remains limited.AIM To evaluate the diagnostic value of conventional EUS for LNM in upper gastrointestinal neoplasia.METHODS Using the search mode of“MeSH+Entry Terms”and according to the predetermined inclusion and exclusion criteria,we conducted a comprehensive search and screening of the PubMed,EMBASE and Cochrane Library databases from January 1,2000 to October 1,2022.Study data were extracted according to the predetermined data extraction form.The quality of the included studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool,and the results of the quality assessment were presented using Review Manager 5.3.5 software.Finally,Stata14.0 software was used for a series of statistical analyses.RESULTS A total of 22 studies were included in our study,including 2986 patients.The pooled sensitivity,specificity,positive likelihood ratio,negative likelihood ratio,diagnostic score and diagnostic odds ratio of conventional EUS in the diagnosis of upper gastrointestinal neoplasia LNM were 0.62[95%confidence interval(CI):0.50-0.73],0.80(95%CI:0.73-0.86),3.15(95%CI:2.46-4.03),0.47(95%CI:0.36-0.61),1.90(95%CI:1.51-2.29)and 6.67(95%CI:4.52-9.84),respectively.The area under the summary receiver operating characteristic curve was 0.80(95%CI:0.76-0.83).Sensitivity analysis indicated that the results of the meta-analysis were stable.There was considerable heterogeneity among the included studies,and the threshold effect was an important source of heterogeneity.Univariable meta-regression and subgroup analysis showed that tumor type,sample size and EUS diagnostic criteria were significant sources of heterogeneity in specificity(P<0.05).No significant publication bias was found.CONCLUSION Conventional EUS has certain clinical value and can assist in the detection of LNM in upper gastrointestinal neoplasia,but it cannot be used as a confirmatory or exclusionary test. 展开更多
关键词 ENDOSONOGRAPHY Esophageal neoplasms Stomach neoplasms Lymphatic metastasis DIAGNOSIS META-ANALYSIS
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三七粉治疗玻璃体切除术后再出血的疗效观察 被引量:2
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作者 吴震宇 徐洁慧 谢佳璐 《国际眼科杂志》 CAS 北大核心 2018年第12期2269-2271,共3页
目的:观察三七粉对于玻璃体切除术后再出血患者的疗效,为该类患者的药物治疗提供新的方向。方法:纳入2010-01/2017-12在我院眼科就诊的玻璃体切除术后再出血的增殖性糖尿病视网膜病变患者共32例32眼,予三七粉口服,1. 5g/次,2次/d,7 d为... 目的:观察三七粉对于玻璃体切除术后再出血患者的疗效,为该类患者的药物治疗提供新的方向。方法:纳入2010-01/2017-12在我院眼科就诊的玻璃体切除术后再出血的增殖性糖尿病视网膜病变患者共32例32眼,予三七粉口服,1. 5g/次,2次/d,7 d为一疗程,连续服用3个疗程后进行观察评估。统计治疗前后患者视力情况、光学相干断层扫描成像质量、玻璃体出血等级,从而判断其疗效。结果:经过3个疗程的治疗后,所有患者均未出现服药后不良反应,总体视力改善率为88%,最佳矫正视力(LogMAR)治疗前为1. 93±0. 46,治疗后为1. 42±0. 5。其中治疗前小数视力≥0. 02、指数~<0. 02、光感的患者治疗后视力改善率为100%,治疗前手动的患者治疗后视力改善率为60%。所有患者光学相干断层扫描成像质量总体改善率为94%,玻璃体出血等级总体改善率为94%。结论:三七粉能有效治疗玻璃体切除术后再出血患者,其能促进玻璃体腔积血吸收,使患者视力尽快提高并且降低二次手术概率。 展开更多
关键词 三七粉 玻璃体切除术后再出血 视力
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Hepatitis B virus-persistent infection and innate immunity defect: Cell-related or virus-related? 被引量:8
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作者 Jian Tang zhen-yu wu +2 位作者 Rong-Juan Dai Jing Ma Guo-Zhong Gong 《World Journal of Clinical Cases》 SCIE 2018年第9期233-241,共9页
The outcomes of hepatitis B virus(HBV) infection are closely related to the age at which infection was acquired. Infection acquired in adult life tends to be selflimited, in contrast to perinatal acquirement, for whic... The outcomes of hepatitis B virus(HBV) infection are closely related to the age at which infection was acquired. Infection acquired in adult life tends to be selflimited, in contrast to perinatal acquirement, for which chronic persistence of the HBV is a general outcome. Innate immunity plays an indispensable role in early virus infection, facilitating virus clearance. However, it has been reported that HBV is under-recognized and poorly eliminated by the innate immune system in the early stages of infection, possibly explaining the long-lasting persistence of viremia afterwards. Furthermore, due to the existence of covalently closed circular DNA, chronic HBV clearance is very difficult, even when patients are given interferon-α and nucleotide/nucleoside analogs for antiviral therapy. The mechanism by which HBV evades innate immune recognition and establishes persistent infection remains a subject of debate. Besides, some researchers are becoming more interested in how to eradicate chronic HBV infection by restoring or boosting innate immunity. This review aimed to summarize the current knowledge on how intrahepatocyte signaling pathways and innate immune cells act after the onset of HBV infection and how these actions are related to the persistence of HBV. We anticipate the insights presented herein to be helpful for future development of novel immune therapeutic strategies to fight HBV infection. 展开更多
关键词 Hepatitis B virus Innate immunity Immune EVASION Pattern recognition RECEPTOR TOLL-LIKE RECEPTOR Natural KILLER CELLS KUPFFER CELLS Dendritic CELLS
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Analysis of single-event transient sensitivity in fully depleted silicon-on-insulator MOSFETs 被引量:3
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作者 Jing-Yan Xu Shu-Ming Chen +2 位作者 Rui-Qiang Song zhen-yu wu Jian-Jun Chen 《Nuclear Science and Techniques》 SCIE CAS CSCD 2018年第4期108-113,共6页
Based on 3 D-TCAD simulations, single-event transient(SET) effects and charge collection mechanisms in fully depleted silicon-on-insulator(FDSOI) transistors are investigated. This work presents a comparison between28... Based on 3 D-TCAD simulations, single-event transient(SET) effects and charge collection mechanisms in fully depleted silicon-on-insulator(FDSOI) transistors are investigated. This work presents a comparison between28-nm technology and 0.2-lm technology to analyze the impact of strike location on SET sensitivity in FDSOI devices. Simulation results show that the most SET-sensitive region in FDSOI transistors is the drain region near the gate. An in-depth analysis shows that the bipolar amplification effect in FDSOI devices is dependent on the strike locations. In addition, when the drain contact is moved toward the drain direction, the most sensitive region drifts toward the drain and collects more charge. This provides theoretical guidance for SET hardening. 展开更多
关键词 Single-event transient Charge COLLECTION BIPOLAR AMPLIFICATION Fully depleted SILICON-ON-INSULATOR
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Molecular typing of familial temporal lobe epilepsy 被引量:2
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作者 Chao Liu Xiao-Zhi Qiao +3 位作者 Zi-Han Wei Mi Cao zhen-yu wu Yan-Chun Deng 《World Journal of Psychiatry》 SCIE 2022年第1期98-107,共10页
The pathogenesis of temporal lobe epilepsy(TLE)was originally considered to be acquired.However,some reports showed that TLE was clustered in some families,indicating a genetic etiology.With the popularity of genetic ... The pathogenesis of temporal lobe epilepsy(TLE)was originally considered to be acquired.However,some reports showed that TLE was clustered in some families,indicating a genetic etiology.With the popularity of genetic testing technology,eleven different types of familial TLE(FTLE),including ETL1-ETL11,have been reported,of which ETL9-ETL11 had not yet been included in the OMIM database.These types of FTLE were caused by different genes/Loci and had distinct characteristics.ETL1,ETL7 and ETL10 were characterized by auditory,visual and aphasia seizures,leading to the diagnosis of familial lateral TLE.ETL2,ETL3 and ETL6 showed prominent autonomic symptom and automatism with or without hippocampal abnormalities,indicating a mesial temporal origin.Febrile seizures were common in FTLEs such as ETL2,ETL5,ETL6 and ETL11.ETL4 was diagnosed as occipitotemporal lobe epilepsy with a high incidence of migraine and visual aura.Considering the diversity and complexity of the symptoms of TLE,neurologists enquiring about the family history of epilepsy should ask whether the relatives of the proband had experienced unnoticeable seizures and whether there is a family history of other neurological diseases carefully.Most FTLE patients had a good prognosis with or without anti-seizure medication treatment,with the exception of patients with heterozygous mutations of the CPA6 gene.The pathogenic mechanism was diverse among these genes and spans disturbances of neuron development,differentiation and synaptic signaling.In this article,we describe the research progress on eleven different types of FTLE.The precise molecular typing of FTLE would facilitate the diagnosis and treatment of FTLE and genetic counseling for this disorder. 展开更多
关键词 Temporal lobe epilepsy Gene mutation Gene locus PHENOTYPES PROGNOSIS
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Neurochemical features of endomorphin-2-containing neurons in the submucosal plexus of the rat colon 被引量:1
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作者 Jun-Ping Li Ting Zhang +6 位作者 Chang-Jun Gao Zhen-Zhen Kou Xu-Wen Jiao Lian-Xiang Zhang zhen-yu wu Zhong-Yi He Yun-Qing Li 《World Journal of Gastroenterology》 SCIE CAS 2015年第34期9936-9944,共9页
AIM:To investigate the distribution and neurochemical phenotype of endomorphin-2(EM-2)-containing neurons in the submucosal plexus of the rat colon.METHODS:The mid-colons between the right and left flexures were remov... AIM:To investigate the distribution and neurochemical phenotype of endomorphin-2(EM-2)-containing neurons in the submucosal plexus of the rat colon.METHODS:The mid-colons between the right and left flexures were removed from rats,and transferred into Kreb's solution. For whole-mount preparations,the mucosal,outer longitudinal muscle and inner circularmuscle layers of the tissues were separated from the submucosal layer attached to the submucosal plexus. The whole-mount preparations from each rat mid-colon were mounted onto seven gelatin-coated glass slides,and processed for immunofluorescence histochemical double-staining of EM-2 with calcitonin gene-related peptide(CGRP),choline acetyltransferase(Ch AT),nitric oxide synthetase(NOS),neuron-specific enolase(NSE),substance P(SP) and vasoactive intestinal peptide(VIP). After staining,all the fluorescence-labeled sections were observed with a confocal laser scanning microscope. To estimate the extent of the co-localization of EM-2 with CGRP,Ch AT,NOS,NSE,SP and VIP,ganglia,which have a clear boundary and neuronal cell outline,were randomly selected from each specimen for this analysis. RESULTS:In the submucosal plexus of the mid-colon,many EM-2-immunoreactive(IR) and NSE-IR neuronal cell bodies were found in the submucosal plexus of the rat mid-colon. Approximately 6 ± 4.2 EM-2-IR neurons aggregated within each ganglion and a few EM-2-IR neurons were also found outside the ganglia. The EM-2-IR neurons were also immunopositive for Ch AT,SP,VIP or NOS. EM-2-IR nerve fibers coursed near Ch AT-IR neurons,and some of these fibers were even distributed around Ch AT-IR neuronal cell bodies. Some EM-2-IR neuronal cell bodies were surrounded by SP-IR nerve fibers,but many long processes connecting adjacent ganglia were negative for EM-2 immunostaining. Long VIP-IR processes with many branches coursed through the ganglia and surrounded the EM-2-IR neurons. The percentages of the EM-2-IR neurons that were also positive for Ch AT,SP,VIP or NOS were approximately 91% ± 2.6%,36% ± 2.4%,44% ± 2.5% and 44% ± 4.7%,respectively,but EM-2 did not co-localize with CGRP. CONCLUSION:EM-2-IR neurons are present in the submucosal plexus of the rat colon and express distinct neurochemical markers. 展开更多
关键词 Endomorphin-2 SUBMUCOSAL PLEXUS ENTERIC neuron COL
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Severe serous cavity bleeding caused by acquired factor V deficiency associated with lymphatic leakage in a hemodialysis patient: A case report 被引量:1
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作者 Wen-Bo Zhao Yan-Ru Chen +4 位作者 Dan Luo Hong-Chun Lin Bing Long zhen-yu wu Hui Peng 《World Journal of Clinical Cases》 SCIE 2019年第17期2556-2561,共6页
BACKGROUND Acquired factor V deficiency is a rare secondary hemorrhagic disease,which can lead to a severe bleeding disorder.CASE SUMMARY We report a 47-year-old hemodialysis patient who presented with severe hemorrha... BACKGROUND Acquired factor V deficiency is a rare secondary hemorrhagic disease,which can lead to a severe bleeding disorder.CASE SUMMARY We report a 47-year-old hemodialysis patient who presented with severe hemorrhagic pleural effusion and hemorrhagic pericardial effusion associated with lymphatic leakage.The laboratory examination revealed decreased factor V activity (2% of population average value).With decreased lymphatic leakage,factor V activity increased (to 46%).Lymph drainage correlated with prothrombin time and active partial thrombin time.The cause of the disease favored an acquired disease.The common causes which trigger factor V inhibitors were excluded.An inhibitor was not detected.It is possible that there was a clotting factor inhibitor leaking with the lymph in the drainage.Inhibitor production may be due to immune dysfunction caused by persistent lymphatic drainage,or that coagulation inhibitors were produced,drained with the lymph,and partly cleared by hemodialysis.CONCLUSION In this case,we have firstly reported factor V deficiency associated with lymphatic leakage in a hemodialysis patient. 展开更多
关键词 ACQUIRED factory V DEFICIENCY LYMPHATIC leakage SEROUS cavity BLEEDING HEMODIALYSIS Case report
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Testing and data reduction of the Chinese Small Telescope Array(CSTAR) for Dome A,Antarctica 被引量:2
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作者 Xu Zhou zhen-yu wu +16 位作者 Zhao-Ji Jiang Xiang-Qun Cui Long-Long Feng Xue-Fei Gong Jing-Yao Hu Qi-Sheng Li Gen-Rong Liu Jun Ma Jia-Li Wang Li-Fan Wang Jiang-Hua wu Li-Rong Xia Jun Yan Xiang-Yan Yuag Feng-Xiang Zhai Ru Zhang Zhen-Xi Zhu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2010年第3期279-290,共12页
The Chinese Small Telescope Array (CSTAR) is the first Chinese astronomical instrument on the Antarctic ice cap. The low temperature and low pressure testing of the data acquisition system was carried out in a labor... The Chinese Small Telescope Array (CSTAR) is the first Chinese astronomical instrument on the Antarctic ice cap. The low temperature and low pressure testing of the data acquisition system was carried out in a laboratory refrigerator and on the 4500 m Pamirs high plateau, respectively. The results from the final four nights of test observations demonstrated that CSTAR was ready for operation at Dome A, Antarctica. In this paper, we present a description of CSTAR and the performance derived from the test observations. 展开更多
关键词 instrumentation: detectors -- techniques: photometric -- stars: variables
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Multicolor photometry of the galaxy cluster A98: substructures and star formation properties
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作者 Li Zhang Qi-Rong Yuan +5 位作者 Xu Zhou Zhao-Ji Jiang Yan-Bin Yang Jun Ma Jiang-Hua wu zhen-yu wu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2010年第1期1-21,共21页
An optical photometric observation with the Beijing-Arizona-Taiwan- Connecticut (BATC) multicolor system is carried out for A98 (z =0.104), a galaxy cluster with two large enhancements in X-ray surface brightness.... An optical photometric observation with the Beijing-Arizona-Taiwan- Connecticut (BATC) multicolor system is carried out for A98 (z =0.104), a galaxy cluster with two large enhancements in X-ray surface brightness. Spectral energy distributions (SEDs) covering 15 intermediate bands are obtained for all sources detected down to V - 20 mag in a field of 58′× 58′. After star-galaxy separation with colorcolor diagrams, a photometric redshift technique is applied to the galaxy sample for further membership determination. The color-magnitude relation is taken as a further restriction of the early-type cluster galaxies. As a result, a list of 198 faint member galaxies is achieved. Based on the newly generated sample of member galaxies, the dynamical substructures, A98N, A98S, and A98W, are investigated in detail. A separate galaxy group, A98X, is also found to the south of the main concentration of A98, which is gravitationally unbound to A98. For 74 spectroscopically confirmed member galaxies, the environmental effect on the star formation history is investigated. The bright galaxies in the core region are found to have shorter time scales of star formation, longer mean stellar ages, and higher interstellar medium metallicities, which can be interpreted in the context of the hierarchical cosmological scenario. 展开更多
关键词 GALAXIES CLUSTERS individual (A98) - galaxies distances and redshifts - galaxies kinematics and dynamics - galaxies evolution - methods data analysis
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The tidal tails of globular cluster Palomar 5 based on the neural networks method
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作者 Hu Zou zhen-yu wu +1 位作者 Jun Ma Xu Zhou 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2009年第10期1131-1148,共18页
The sixth Data Release (DR6) of the Sloan Digital Sky Survey (SDSS) provides more photometric regions, new features and more accurate data around globular cluster Palomar 5. A new method, Back Propagation Neural N... The sixth Data Release (DR6) of the Sloan Digital Sky Survey (SDSS) provides more photometric regions, new features and more accurate data around globular cluster Palomar 5. A new method, Back Propagation Neural Network (BPNN), is used to estimate the cluster membership probability in order to detect its tidal tails. Cluster and field stars, used for training the networks, are extracted over a 40 × 20 deg^2 field by color-magnitude diagrams (CMDs). The best BPNNs with two hidden layers and a Levenberg-Marquardt (LM) training algorithm are determined by the chosen cluster and field samples. The membership probabilities of stars in the whole field are obtained with the BPNNs, and contour maps of the probability distribution show that a tail extends .5.42° to the north of the cluster and another tail extends 3.77° to the south. The tails are similar to those detected by Odenkirchen et al., but no more debris from the cluster is found to the northeast in the sky. The radial density profiles are investigated both along the tails and near the cluster center. Quite a few substructures are discovered in the tails. The number density profile of the cluster is fitted with the King model and the tidal radius is determined as 14.28'. However, the King model cannot fit the observed profile at the outer regions (R 〉 8') because of the tidal tails generated by the tidal force. Luminosity functions of the cluster and the tidal tails are calculated, which confirm that the tails originate from Palomar 5. 展开更多
关键词 METHODS statistical -- galaxy halo -- galaxy structure -- globular cluster individual (Palomar 5)
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Old stellar population synthesis:new age and mass estimates for Mayall II = G1
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作者 Jun Ma Richard de Grijs +8 位作者 Zhou Fan Soo-Chang Rey zhen-yu wu Xu Zhou Jiang-Hua wu Zhao-Ji Jiang Jian-Sheng Chen Kyungsook Lee Sangmo Tony Sohn 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2009年第6期641-652,共12页
Mayall Ⅱ = G1 is one of the most luminous globular clusters (GCs) in M31. Here, we determine its age and mass by comparing multicolor photometry with theoretical stellar population synthesis models. Based on far- a... Mayall Ⅱ = G1 is one of the most luminous globular clusters (GCs) in M31. Here, we determine its age and mass by comparing multicolor photometry with theoretical stellar population synthesis models. Based on far- and near-ultraviolet GALEX photometry, broad-band UBVRI, and infrared JHKs 2MASS data, we construct the most extensive spectral energy distribution of G 1 to date, spanning the wavelength range from 1538 to 20 000A. A quantitative comparison with a variety of simple stellar population (SSP) models yields a mean age which is consistent with G1 being among the oldest building blocks of M31 and having formed within ~1.7 Gyr after the Big Bang. Irrespective of the SSP model or stellar initial mass function adopted, the resulting mass estimates (of order 10^7M⊙) indicate that GI is one of the most massive GCs in the Local Group. However, we speculate that the cluster's exceptionally high mass suggests that it may not be a genuine GC. Our results also suggest that G1 may contain, on average, (1.65±0.63) × 10^2L⊙ far-ultraviolet-bright, hot, extreme horizontal-branch stars, depending on the adopted SSP model. In addition, we demonstrate that extensive multi-passband photometry coupled with SSP analysis enables one to obtain age estimates for old SSPs that have similar accuracies as those from integrated spectroscopy or resolved stellar photometry, provided that some of the free parameters can be constrained independently. 展开更多
关键词 GALAXIES individual (M31) -- galaxies star clusters -- galaxies stellar content
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Chemical abundances of three new Ba stars from the Keck/HIRES spectra
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作者 刘帅 王靓 +4 位作者 施建荣 武振宇 闫宏亮 高琦 李春乾 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2021年第11期67-78,共12页
Based on high resolution,high signal-to-noise(S/N)ratio spectra from Keck/HIRES,we have determined abundances of 20 elements for 18 Ba candidates.The parameter space of these stars is in the range of 4880≤Teff≤6050 ... Based on high resolution,high signal-to-noise(S/N)ratio spectra from Keck/HIRES,we have determined abundances of 20 elements for 18 Ba candidates.The parameter space of these stars is in the range of 4880≤Teff≤6050 K,2.56≤log g≤4.53 dex and-0.27≤[Fe/H]≤0.09 dex.It is found that four of them can be identified as Ba stars with[s/Fe]>0.25 dex(s:Sr,Y,Zr,Ba,La,Ce and Nd),and three of them are newly discovered,which include two Ba giants(HD 16178 and HD 22233)and one Ba subgiant(HD 2946).Our results show that the abundances ofα,odd and iron-peak elements(O,Na,Mg,Al,Si,Ca,Sc,Ti,Mn,Ni and Cu)for our program stars are similar to those of the thin disk,while the distribution of[hs/ls](hs:Ba,La,Ce and Nd,ls:Sr,Y and Zr)ratios of our Ba stars is similar to those of the known Ba objects.None of the four Ba stars show clear enhancement in carbon including the known CH subgiant HD 4395.It is found that three of the Ba stars present clear evidence of hosting stellar or sub-stellar companions from the radial velocity data. 展开更多
关键词 GALAXY Ba stars Chemical abundances Binary
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Strategy to mitigate single event upset in 14-nm CMOS bulk FinFET technology
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作者 李东青 刘天奇 +3 位作者 赵培雄 吴振宇 王铁山 刘杰 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第5期527-534,共8页
Three-dimensional(3 D)TCAD simulations demonstrate that reducing the distance between the well boundary and N-channel metal-oxide semiconductor(NMOS)transistor or P-channel metal-oxide semiconductor(PMOS)transistor ca... Three-dimensional(3 D)TCAD simulations demonstrate that reducing the distance between the well boundary and N-channel metal-oxide semiconductor(NMOS)transistor or P-channel metal-oxide semiconductor(PMOS)transistor can mitigate the cross section of single event upset(SEU)in 14-nm complementary metal-oxide semiconductor(CMOS)bulk Fin FET technology.The competition of charge collection between well boundary and sensitive nodes,the enhanced restoring currents and the change of bipolar effect are responsible for the decrease of SEU cross section.Unlike dualinterlock cell(DICE)design,this approach is more effective under heavy ion irradiation of higher LET,in the presence of enough taps to ensure the rapid recovery of well potential.Besides,the feasibility of this method and its effectiveness with feature size scaling down are discussed. 展开更多
关键词 TCAD simulation FINFET single event upset(SEU)mitigation
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A catalogue of 74 new open clusters found in Gaia Data-Release 2
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作者 Zhi-Hong He Ye Xu +2 位作者 Chao-Jie Hao zhen-yu wu Jing-Jing Li 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2021年第4期216-224,共9页
Based on astrometric data from Gaia Data-Release 2(DR2),we employ an unsupervised machine learning method to blindly search for open star clusters in the Milky Way within the Galactic latitude range of|b|<20°.... Based on astrometric data from Gaia Data-Release 2(DR2),we employ an unsupervised machine learning method to blindly search for open star clusters in the Milky Way within the Galactic latitude range of|b|<20°.In addition to 2080 known clusters,74 new open cluster candidates are found.In this work,we present the positions,apparent radii,parallaxes,proper motions and member stars of these candidates.Meanwhile,to obtain the physical parameters of each candidate cluster,stellar isochrones are fit to the photometric data.The results show that the apparent radii and the observed proper motion dispersions of these new candidates are consistent with those of open clusters previously identified in Gaia DR2. 展开更多
关键词 Galaxy:open clusters and associations methods:data analysis surveys
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Late-time photometry of two nearby type II-P supernovae: 2004dj and 2004et
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作者 Tian-Meng Zhang Xiao-Feng Wang +5 位作者 Xu Zhou Jun Ma Zhao-Ji Jiang Jiang-Hua wu zhen-yu wu Stephane Basa 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2009年第7期783-790,共8页
We present late-time photometry for two bright type II-P supernovae (SNe) 2004dj and 2004et, extending over 400 d after the explosion, which are measured with a set of intermediate-band filters that have the advanta... We present late-time photometry for two bright type II-P supernovae (SNe) 2004dj and 2004et, extending over 400 d after the explosion, which are measured with a set of intermediate-band filters that have the advantage of tracing the strength variations of some spectral features. Although these two SNe II-P exhibit similar photometric evolution at earlier times, they diverge during the nebular phase. SN 2004dj shows a slow late-time decline rate with - 0.7 ±0.1 mag (100d)^-1 during the period ranging from t ≈ 200 - 300 d after the explosion, while SN 2004et shows a much faster decline rate at a comparable phase, e.g., 1.3 ± 0.1 mag (100d)^-1. The steeper decay rate seen in SN 2004et is likely due to dust formation in the explosion ejecta. Based on intermediate-band photometry, we derived the evolution of the feature lines [e.g., Hα] of SNe 2004dj and 2004et which are similar in flux at comparable phases but perhaps with significantly different decay rates. The origin of the observed variations in the continuum and the feature lines is briefly discussed. 展开更多
关键词 supernovae general - supernovae: individual (SN 2004dj SN 2004et) -techniques: photometric
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Variable stars in the field of open cluster NGC 2126
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作者 Shun-Fang Liu zhen-yu wu +5 位作者 Xiao-Bin Zhang Jiang-Hua wu Jun Ma Zhao-Ji Jiang Jian-Sheng Chen Xu Zhou 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2009年第7期791-802,共12页
We report the results of a time-series CCD photometric survey of variable stars in the field of open cluster NGC 2126. In about a one square degree field covering the cluster, a total of 21 variable candidates are det... We report the results of a time-series CCD photometric survey of variable stars in the field of open cluster NGC 2126. In about a one square degree field covering the cluster, a total of 21 variable candidates are detected during this survey, of which 16 are newly found. The periods, classifications and spectral types of 14 newly discovered variables are discussed, which consist of six eclipsing binary systems, three pulsating variable stars, three long period variables, one RS CVn star, and one W UMa or δ Scuff star. In addition, there are two variable candidates, the properties of which cannot be determined. By a method based on fitting observed spectral energy distributions of stars with theoretical ones, the membership probabilities and the fundamental parameters of this cluster are determined. As a result, five variables are probably members of NGC 2126. The fundamental parameters of this cluster are determined as: metallicity to be 0.008 Z, age log(t) = 8.95, distance modulus (m - M)0 = 10.34 and reddening value E(B - V) = 0.55 mag. 展开更多
关键词 open clusters: individual (NGC 2126) - stars: variables (general) - bina- ties: general
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South Galactic Cap u-band Sky Survey(SCUSS):Project Overview
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作者 Xu Zhou Xiao-Hui Fan +13 位作者 Zhou Fan Bo-Liang He Lin-Hua Jiang Zhao-Ji Jiang Yi-Peng Jing Michael Lesser Jun Ma Jun-Dan Nie Shi-Yin Shen Jia-Li Wang zhen-yu wu Tian-Meng Zhang Zhi-Min Zhou Hu Zou 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2016年第4期133-144,共12页
The South Galactic Cap u-band Sky Survey (SCUSS) was established in 2009 in order to provide a photometric input catalog for target selection of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST... The South Galactic Cap u-band Sky Survey (SCUSS) was established in 2009 in order to provide a photometric input catalog for target selection of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) project. SCUSS is an international cooperative project between National Astronomical Observatories, Chinese Academy of Sciences, and Steward Observatory at the University of Arizona, using the 90 inch (2.3 m) Bok telescope on Kitt Peak. The telescope is equipped with a prime focus camera that is composed of a mosaic of four 4096 × 4096 CCDs and has a field of view of about 1 deg2. From 2009 to 2013, SCUSS performed a sky survey of an approximately 5000 deg2 field of the South Galactic Cap in u band, including the Galactic anticenter area and the SDSS-IV extended imaging area. The limiting magnitude of SCUSS is deeper than 23 mag (at a signal-to-noise ratio of 5). In this paper, we briefly describe the goals of this project, method of observations and data reduction, and we also introduce current and potential scientific activities related to the SCUSS project. 展开更多
关键词 observation: sky survey -- techniques: data reduction -- objects: stars and galaxies
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Metal abundance and kinematical properties of the M81 globular cluster system
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作者 Jun Ma zhen-yu wu +7 位作者 Tian-Meng Zhang Song Wang Zhou Fan Jiang-Hua wu Hu Zou Cui-Hua Du Xu Zhou Qi-Rong Yuan 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2013年第4期399-410,共12页
We present metal abundance properties of 144 globular clusters associated with M81. These globulars represent the largest globular cluster sample in M81 till now. Our main results are: the distribution of metalliciti... We present metal abundance properties of 144 globular clusters associated with M81. These globulars represent the largest globular cluster sample in M81 till now. Our main results are: the distribution of metallicities is bimodal, with metallicity peaks at [Fe/H] -1.51 and -0.58, and the metal-poor globular clusters tend to be less spatially concentrated than the metal-rich ones; the metal-rich globular clusters in M81 do not demonstrate a centrally concentrated spatial distribution like the metalrich ones in M31 do; like our Galaxy and M31, the globular clusters in M81 have a small radial metallicity gradient. These results are consistent with those obtained from a small sample of M81 globular clusters. In addition, this paper shows that there is evidence that a strong rotation of the M81 globular cluster system around the minor axis exists, and that rotation is present in the metal-rich globular cluster subsample, but the metal-poor globular cluster subsample shows no evidence of rotation. The most significant difference between the rotation of the metal-rich and metal-poor globular clusters occurs at intermediate projected galactocentric radii. Our results confirm the conclusion of Schroder et al. that M81's metal-rich globular clusters at intermediate projected radii are associated with a thick disk of M81. 展开更多
关键词 galaxies: individual (M81) -galaxies: star clusters globular clusters:general
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Multicolor photometry of the nearby galaxy cluster A119
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作者 Jin-Tao Tian Qi-Rong Yuan +6 位作者 Xu Zhou Zhao-Ji Jiang Jun Ma Jiang-Hua wu zhen-yu wu Tian-Meng Zhang Hu Zou 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2012年第10期1381-1401,共21页
This paper presents multicolor optical photometry of the nearby galaxy cluster Abell 119 (z = 0.0442) with the Beijing-Arizona-Taiwan-Connecticut system of 15 intermediate bands. Within the BATC field of view of 58... This paper presents multicolor optical photometry of the nearby galaxy cluster Abell 119 (z = 0.0442) with the Beijing-Arizona-Taiwan-Connecticut system of 15 intermediate bands. Within the BATC field of view of 58'× 58', there are 368 galaxies with known spectroscopic redshifts, including 238 member galaxies (called sample I). Based on the spectral energy distributions of 1376 galaxies brighter than iBATC ---- 19.5, the photometric redshift technique and the color-magnitude relation of early-type galaxies are applied to select faint member galaxies. As a result, 117 faint galaxies were selected as new member galaxies. Combined with sample I, an enlarged sample (called sample II) of 355 member galaxies is obtained. Spatial distribution and localized velocity structure for two samples demonstrate that A119 is a dynami- cally complex cluster with at least three prominent substructures in the central region within 1 Mpc. A large velocity dispersion for the central clump indicates a merging along the line of sight. No significant evidence for morphology or luminosity segrega- tions is found in either sample. With the PEGASE evolutionary synthesis model, the environmental effect on the properties of star formation is confirmed. Faint galaxies in the low-density region tend to have longer time scales of star formation, smaller mean stellar ages, and lower metallicities in their interstellar medium, which is in agreement with the context of the hierarchical cosmological scenario. 展开更多
关键词 galaxies: clusters: individual (A119)- galaxies: distances and redshifts-- galaxies: evolution-- galaxies: kinematics and dynamics-- methods: data analysis
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The Structure of the Galactic Halo
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作者 Cui-Hua Du zhen-yu wu +1 位作者 Jun Ma Xu Zhou 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2008年第5期566-574,共9页
We used the star counts in 21 BATC fields obtained with the National Astronomical Observatories (NAOC) 60/90 cm Schmidt Telescope to study the structure of the Galactic halo. Adopting a de Vaucouleurs r1/4 law halo,... We used the star counts in 21 BATC fields obtained with the National Astronomical Observatories (NAOC) 60/90 cm Schmidt Telescope to study the structure of the Galactic halo. Adopting a de Vaucouleurs r1/4 law halo, we found that the halo is somewhat flatter (c/a - 0.4) towards the Galactic center than in the anticentre and antirotation direction (c/a 〉 0.4). We also notice that the axial ratios are smaller (flatter) towards the low latitude fields than the high latitude fields, except for a few fields. We provide robust limits on the large-scale flattening of the halo. Our analysis shows that the axial ratio of the halo may vary with distance and the observation direction. At large Galactocentric radii, the halo may not have a smooth density distribution, but rather, it may be largely composed of overlapping streams or substructures, which provides a support for the hybrid formation model. 展开更多
关键词 Galaxy structure - Galaxy halo - Galaxy fundamental parameters - Galaxy formation
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