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Characterize and optimize the four-wave mixing in dual-interferometer coupled silicon microrings
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作者 吴超 刘英文 +7 位作者 顾晓文 薛诗川 郁鑫鑫 孔月婵 强晓刚 吴俊杰 朱志宏 徐平 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第10期198-203,共6页
By designing and fabricating a series of dual-interferometer coupled silicon microrings, the coupling condition of the pump, signal, and idler beams can be engineered independently and then we carried out both the con... By designing and fabricating a series of dual-interferometer coupled silicon microrings, the coupling condition of the pump, signal, and idler beams can be engineered independently and then we carried out both the continuous-wave and pulse pumped four-wave mixing experiments to verify the dependence of conversion efficiency on the coupling conditions of the four interacting beams, respectively. Under the continuous-wave pump, the four-wave mixing efficiency gets maximized when both the pump and signal/idler beams are closely operated at the critical coupling point, while for the pulse pump case, the efficiency can be enhanced greatly when the pump and converted idler beams are all overcoupled. These experiment results agree well with our theoretical calculations. Our design provides a platform for explicitly characterizing the four-wave mixing under different pumping conditions, and offers a method to optimize the four-wave mixing, which will facilitate the development of on-chip all-optical signal processing with a higher efficiency or reduced pump power. 展开更多
关键词 SILICON resonators four-wave mixing MACH-ZEHNDER INTERFEROMETER
Urinary metabolomics analysis identifies key biomarkers of different stages of nonalcoholic fatty liver disease 预览
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作者 Shu Dong Zong-Ying Zhan +6 位作者 Hong-Yan Cao Chao Wu Yan-qin Bian Jian-Yuan Li Gen-Hong Cheng Ping Liu Ming-Yu Sun 《世界胃肠病学杂志:英文版》 SCIE CAS 2017年第15期2771-2784,共14页
AIM To identify a panel of biomarkers that can distinguish between non-alcoholic fatty liver disease(NAFLD) and non-alcoholic steatohepatitis(NASH), and explore molecular mechanism involved in the process of developin... AIM To identify a panel of biomarkers that can distinguish between non-alcoholic fatty liver disease(NAFLD) and non-alcoholic steatohepatitis(NASH), and explore molecular mechanism involved in the process of developing NASH from NAFLD.METHODS Biomarkers may differ during stages of NAFLD. Urine and blood were obtained from non-diabetic subjects with NAFLD and steatosis, with normal liver function(n = 33), from patients with NASH, with abnormal liver function(n = 45), and from healthy age and sex-matched controls(n = 30). Samples were subjected to metabolomic analysis to identify potential non-invasive biomarkers. Differences in urinary metabolic profiles were analyzed using liquid chromatography tandem mass spectrometry with principal component analysis and partial least squares-discriminate analysis.RESULTS Compared with NAFLD patients, patients with NASH had abnormal liver function and high serum lipid concentrations. Urinary metabonomics found differences in 31 metabolites between these two groups, including differences in nucleic acids and amino acids. Pathway analysis based on overlapping metabolites showed that pathways of energy and amino acid metabolism, as well as the pentose phosphate pathway, were closely associated with pathological processes in NAFLD and NASH.CONCLUSION These findings suggested that a panel of biomarkers could distinguish between NAFLD and NASH, and could help to determine the molecular mechanism involved in the process of developing NASH from NAFLD. Urinary biomarkers may be diagnostic in these patients and could be used to assess responses to therapeutic interventions. 展开更多
关键词 尿 metabonomics 不含酒精的脂肪肝疾病 STEATOHEPATITIS
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Therapeutic mechanism of Yīn-Chén-Hāo decoction in hepatic diseases 预览
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作者 Jian-Yuan Li Hong-Yan Cao +6 位作者 Lin Sun Run-Fei Sun Chao Wu Yan-Qin Bian Shu Dong Ping Liu Ming-Yu Sun 《World Journal of Gastroenterology》 SCIE CAS 2017年第7期
Yīn-Chén-Hāo decoction(YCHD) is a traditional Chinese medicine formula composed of capillaris(Artemisia capillaris), gardenia(Gardenia jasminoides), and rhubarb(Rheum rhabarbarum) that is used for the treatment... Yīn-Chén-Hāo decoction(YCHD) is a traditional Chinese medicine formula composed of capillaris(Artemisia capillaris), gardenia(Gardenia jasminoides), and rhubarb(Rheum rhabarbarum) that is used for the treatment of damp-heat jaundice. In modern clinics, YCHD is mostly used for hepatic diseases. This review summarizes the biological activities of YCHD and its medical applications. The main active compounds of YCHD are chlorogenic acid, rhein, geniposide, emodin, and scoparone. The pharmacological actions of YCHD include inhibition of hepatic steatosis, apoptosis, necrosis, anti-inflammation, and immune regulation. YCHD could be developed as a new therapeutic strategy for the treatment of hepatic diseases. 展开更多
关键词 Yn-Ch ? 鶂髧 ? 韧蒚夠 ? ??? 潈躅髧? 雧? 髧? ? ?? 蔬??
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Optimization of the End Effect of Hilbert-Huang transform (HAT)
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作者 Chenhuan Lv Jun ZHAO +2 位作者 Chao WU Tiantai GUO Hongjiang CHEN 《中国机械工程学报:英文版》 SCIE EI CAS CSCD 2017年第3期732-745,共14页
In fault diagnosis of rotating machinery, Hilbert-Huang transform(HHT) is often used to extract the fault characteristic signal and analyze decomposition results in time-frequency domain. However, end effect occurs in... In fault diagnosis of rotating machinery, Hilbert-Huang transform(HHT) is often used to extract the fault characteristic signal and analyze decomposition results in time-frequency domain. However, end effect occurs in HHT, which leads to a series of problems such as modal aliasing and false IMF(Intrinsic Mode Function). To counter such problems in HHT, a new method is put forward to process signal by combining the generalized regression neural network(GRNN) with the boundary local characteristic-scale continuation(BLCC).Firstly, the improved EMD(Empirical Mode Decomposition) method is used to inhibit the end effect problem that appeared in conventional EMD. Secondly, the generated IMF components are used in HHT. Simulation and measurement experiment for the cases of time domain,frequency domain and related parameters of HilbertHuang spectrum show that the method described here can restrain the end effect compared with the results obtained through mirror continuation, as the absolute percentage of the maximum mean of the beginning end point offset and the terminal point offset are reduced from 30.113% and27.603% to 0.510% and 6.039% respectively, thus reducing the modal aliasing, and eliminating the false IMF components of HHT. The proposed method can effectively inhibit end effect, reduce modal aliasing and false IMF components, and show the real structure of signal components accurately. 展开更多
关键词 端点效应 HILBERT 优化 机械故障诊断 故障特征信号 回归神经网络 经验模式分解 HHT
中国螳螂四新纪录属六新纪录种(螳螂目)(英文)
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作者 吴超 刘春香 《昆虫分类学报》 CSCD 2017年第1期15-23,共9页
记述中国螳螂4新纪录属和6新纪录种。分别为:捷跳螳属Gimantis Giglio-Tos,1915的中南捷跳螳G.authaemon Wood-Mason,1882;孔雀螳属Pseudempusa Brunner v.W.,1893的华丽孔雀螳P.pinnapavonis Brunner,1892;箭螳属Toxodera Serville,183... 记述中国螳螂4新纪录属和6新纪录种。分别为:捷跳螳属Gimantis Giglio-Tos,1915的中南捷跳螳G.authaemon Wood-Mason,1882;孔雀螳属Pseudempusa Brunner v.W.,1893的华丽孔雀螳P.pinnapavonis Brunner,1892;箭螳属Toxodera Serville,1837的赫氏箭螳T.hauseri Roy,2009;羲和螳属Heliomantis Giglio-Tos,1915的端斑羲和螳H.elegans(Navas,1904);耀螳属Nemotha Wood-Mason,1884的金色耀螳Nemotha metallica Westwood,1845;苔螳属Majangella Giglio-Tos,1915的莫氏苔螳Majangella moultoni Giglio-Tos,1915。并给出了6新纪录种的整体图及特征图。 展开更多
关键词 螳螂 分类 分布
TRPV5/6通道在急性髓系白血病中的表达研究 预览 被引量:1
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作者 吴超 杨新宇 +2 位作者 李璇 周明 肖佩玲 《中国现代医学杂志》 CAS 北大核心 2017年第1期71-76,共6页
目的 探讨瞬时受体电位通道V5(TRPV5)、瞬时受体电位通道V6(TRPV6)在急性髓系白血病(AML)中的表达。方法 提取AML患者骨髓细胞、捐献者造血干细胞,以及AML细胞株的蛋白和总RNA,运用实时荧光定量聚合酶链反应(q RT-PCR)及Western... 目的 探讨瞬时受体电位通道V5(TRPV5)、瞬时受体电位通道V6(TRPV6)在急性髓系白血病(AML)中的表达。方法 提取AML患者骨髓细胞、捐献者造血干细胞,以及AML细胞株的蛋白和总RNA,运用实时荧光定量聚合酶链反应(q RT-PCR)及Western blot检测TRPV5/6基因和蛋白的表达水平,并分析AML患者临床指标与TRPV5/6表达水平的相关性。结果 初治组、复发组、细胞株组结果显示,TRPV5/6的表达高于对照组,差异有统计学意义(〈0.05),而完全缓解组与对照组TRPV5/6的表达比较,差异无统计学意义(〉0.05)。AML患者TRPV5/6表达与骨髓原始细胞百分比呈正相关(〈0.05),而与外周血白细胞计数、血红蛋白、血小板计数、性别、年龄及骨髓染色体核型比较,差异无统计学意义(〉0.05)。结论 TRPV5/6通道在AML中表达上调,且与肿瘤负荷相关,有望成为白血病诊断的新型标志物,以及预后评估的分子靶点。 展开更多
关键词 急性髓系白血病 TRPV5/6通道 骨髓细胞
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Studies on the nucleation of MBE grown Ⅲ-nitride nanowires on Si
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作者 鄂炎雄 郝智彪 +7 位作者 余佳东 吴超 汪莱 熊兵 王健 韩彦军 孙长征 罗毅 《中国物理B:英文版》 SCIE EI CAS CSCD 2017年第1期344-347,共4页
GaN and AlN nanowires(NWs) have attracted great interests for the fabrication of novel nano-sized devices. In this paper, the nucleation processes of GaN and AlN NWs grown on Si substrates by molecular beam epitaxy... GaN and AlN nanowires(NWs) have attracted great interests for the fabrication of novel nano-sized devices. In this paper, the nucleation processes of GaN and AlN NWs grown on Si substrates by molecular beam epitaxy(MBE)are investigated. It is found that GaN NWs nucleated on in-situ formed Si3N4 fully release the stress upon the interface between GaN NW and amorphous Si3N4 layer, while AlN NWs nucleated by aluminization process gradually release the stress during growth. Depending on the strain status as well as the migration ability of Ⅲ group adatoms, the different growth kinetics of GaN and AlN NWs result in different NW morphologies, i.e., GaN NWs with uniform radii and AlN NWs with tapered bases. 展开更多
关键词 分子束外延 成核生长 氮化硅 纳米线 AlN GaN SI3N4 生长动力学
咀嚼口香糖对结直肠癌术后肠道功能作用的Meta分析 预览 被引量:4
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作者 温尊甲 王文婷 +2 位作者 梅彬彬 吴超 沈梅芬 《世界华人消化杂志》 CAS 2017年第2期147-158,共12页
目的评价术后咀嚼口香糖对结直肠癌术后肠道功能恢复的作用.方法电子检索PubMed和EMBASE等国内外数据库内至2016-06探讨结直肠癌术后咀嚼口香糖效果的随机对照试验(randomized controlled trials,RCTs).采用RevMan5.3软件进行数据合... 目的评价术后咀嚼口香糖对结直肠癌术后肠道功能恢复的作用.方法电子检索PubMed和EMBASE等国内外数据库内至2016-06探讨结直肠癌术后咀嚼口香糖效果的随机对照试验(randomized controlled trials,RCTs).采用RevMan5.3软件进行数据合并分析.结果共纳入22个RCTs,2285位研究对象.Meta分析显示,术后咀嚼口香糖在首次排气[-0.57,95%置信区间(confidence interval,CI):-0.74-(-0.41)]、排便[-0.62,95%CI:-1.06-(-0.18)]、肠蠕动恢复[-0.44,95%CI:-0.72-(-0.16)]、血清胃泌素水平(29.92,95%CI:15.65-44.19)、进食时间[-1.33,95%CI:-2.19-(-0.48)],术后住院时间[-1.33,95%CI:-2.19-(-0.48)]和肠梗阻(0.33,95%CI:0.14-0.78)上有显著作用差异,而在术后恶心(0.90,95%CI:0.59-1.39)、呕吐(0.91,95%CI:0.59-1.39)、腹胀(0.62,95%CI:0.36-1.06)和死亡率(2.25,95%CI:0.63-8.09)上并无作用差异.结论结直肠癌术后咀嚼口香糖可促进肠道功能的恢复,但对减少术后并发症作用有限,有待高质量的RCTs作进一步探讨. 展开更多
关键词 口香糖 直肠 结肠 手术 肠道功能 护理 META分析
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影响特发性黄斑裂孔玻璃体切割术疗效的相关因素分析 预览 被引量:2
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作者 吴超 游志鹏 《国际眼科杂志》 CAS 2016年第5期912-915,共4页
目的:分析影响特发性黄斑裂孔玻璃体切割术后影响效果的相关因素。方法:选取2012-05/2015-09在我院眼科治疗的特发性黄斑裂孔患者100例100眼,经玻璃体切割术后,比较治疗前后患者的最佳矫正视力(BCVA)和OCT检查参数的差异;对术后BCV... 目的:分析影响特发性黄斑裂孔玻璃体切割术后影响效果的相关因素。方法:选取2012-05/2015-09在我院眼科治疗的特发性黄斑裂孔患者100例100眼,经玻璃体切割术后,比较治疗前后患者的最佳矫正视力(BCVA)和OCT检查参数的差异;对术后BCVA与术前BCVA和OCT检查参数做Pearson相关分析和多元线性回归分析。结果:患者治疗后视力检查BCVA值为0.357±0.172,高于治疗前(0.137±0.115),差异具有统计学意义(P〈0.05);治疗后OCT检查,基底直径、最小直径、裂孔高度、黄斑部视网膜厚度均低于治疗前,差异具有统计学意义(P〈0.05);Pearson相关分析结果显示:术后BCVA与基底直径(r=-0.397,P〈0.01)和最小直径(r=-0.397,P〈0.01)呈负相关;术后BCVA与裂孔高度(r=0.399,P〈0.01)、黄斑部视网膜厚度(r=0.345,P〈0.01)、MHI(r=0.318,P=0.001)、HPF(r=0.417,P〈0.01)呈正相关;多元线性回归分析结果显示:术后BCVA与黄斑部视网膜厚度呈正相关(T=2.323,P=0.022)。结论:玻璃体切割术治疗特发性黄斑裂孔效果良好,且术前OCT检查参数与术后视力恢复呈高度相关。 展开更多
关键词 特发性黄斑裂孔 玻璃体切割术 最佳矫正视力 OCT检查 相关因素分析
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激光联合不同硅胶管植入治疗不同部位泪道阻塞的疗效 预览 被引量:8
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作者 杨旭 陈桦 +6 位作者 吕宇 张升庆 伍超 田菁 任敏子 陈旺 邓建民 《国际眼科杂志》 CAS 2016年第1期168-170,共3页
目的:观察激光联合新型一次性使用泪道再通管(RS型)或泪道扩张引流管(鼻泪管)治疗不同部位泪道阻塞疾病的疗效。方法:针对2011-01/2013-12我院548例657眼泪道阻塞患者,其中泪小管(含泪总管)阻塞患者236例298眼,采用KTP激光联合... 目的:观察激光联合新型一次性使用泪道再通管(RS型)或泪道扩张引流管(鼻泪管)治疗不同部位泪道阻塞疾病的疗效。方法:针对2011-01/2013-12我院548例657眼泪道阻塞患者,其中泪小管(含泪总管)阻塞患者236例298眼,采用KTP激光联合泪道再通管(RS型)植入术;鼻泪管阻塞患者312例359眼,采用KTP激光联合泪道扩张引流管(鼻泪管)植入术,术后坚持泪道冲洗,手术3mo后拔除支架,以拔管后3mo冲洗泪道情况及患者自觉溢泪情况作为评定标准。结果:泪小管(或泪总管)阻塞的患者行KTP激光联合新型RS型泪道再通管植入术,其中治愈248眼,好转33眼,无效17眼;鼻泪管阻塞的患者行KTP激光联合泪道扩张引流管植入术,其中治愈301眼,好转19眼,无效39眼。有效601眼,总有效率91.5%。结论:泪道阻塞患者治疗过程中需制定个性化治疗方案,针对泪道不同部位阻塞激光联合不同硅胶管植入经临床观察疗效肯定,可作为基层医院泪道阻塞患者首选治疗方式。 展开更多
关键词 KTP激光 泪道阻塞 硅胶管植入
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巨噬细胞亚群与肝病研究进展 预览
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作者 武超 刘平 +1 位作者 孙明瑜 边艳琴 《世界华人消化杂志》 CAS 2016年第33期4491-4497,共7页
巨噬细胞在肝脏的炎症免疫、损伤修复、纤维化和肿瘤的发生发展中都有非常重要的作用.肝脏在不同疾病状态下所形成的特有的微环境直接影响巨噬细胞的表型和功能,而巨噬细胞的表型和功能也直接参与肝脏疾病的进程和预后.本文就巨噬细胞... 巨噬细胞在肝脏的炎症免疫、损伤修复、纤维化和肿瘤的发生发展中都有非常重要的作用.肝脏在不同疾病状态下所形成的特有的微环境直接影响巨噬细胞的表型和功能,而巨噬细胞的表型和功能也直接参与肝脏疾病的进程和预后.本文就巨噬细胞的表型转换及其在多种肝病如脂肪肝、肝硬化和肝癌等发生发展中的作用和意义进行综述. 展开更多
关键词 巨噬细胞 肝病 表型 炎症免疫 纤维化 肿瘤
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The THU-NAOC transient survey: the performance and results from the first year
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作者 Tian-Meng Zhang Xiao-Feng Wang +18 位作者 Jun-Cheng Chen Ju-Jia Zhang Li Zhou Wen-Xiong Li Qing Liu Jun Mo Kai-Cheng Zhang Xin-Yu Yao Xu-Lin Zhao Xu Zhou Jun-Dan Nie Fang Huang Zhao-Ji Jiang Jun Ma Ling-Zhi Wang Chao Wu Zhi-Min Zhou Hu Zou Li-Fan Wang 《天文和天体物理学研究:英文版》 SCIE CAS CSCD 2015年第2期215-224,共10页
The Tsinghua University-National Astronomical Observatories, Chinese Academy of Sciences (NAOC) Transient Survey is an automatic survey that conducts a systematic exploration of optical transients. This project util... The Tsinghua University-National Astronomical Observatories, Chinese Academy of Sciences (NAOC) Transient Survey is an automatic survey that conducts a systematic exploration of optical transients. This project utilizes a 60/90 cm Schmidt telescope at the Xinglong Station of NAOC. This survey repeatedly covers - 1000 square degrees of the northern sky with a cadence of 34 d. With an exposure of 60 s, the survey reaches a limiting unfiltered magnitude of about 19.5 mag, which enables us to discover supernovae in their relatively young stages. We describe the overall performance of our survey during the first year and present some preliminary results. 展开更多
关键词 SUPERNOVAE -- QUASARS and active GALACTIC NUCLEI -- STARS
Photometric Calibration of the Lunar-based Ultraviolet Telescope for Its First Six Months of Operation on the Lunar Surface
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作者 Jing Wang Li Cao +10 位作者 Xian-Min Meng Hong-Bo Cai Jing-Song Deng Xu-Hui Han Yu-Lei Qiu Fang Wang Shen Wang Wei-Bin Wen Chao Wu Jian-Yan Wei Jing-Yao Hu 《天文和天体物理学研究:英文版》 SCIE CAS CSCD 2015年第7期1068-1076,共9页
We describe the photometric calibration of the Lunar-based Ultraviolet Telescope(LUT), the first robotic astronomical telescope working on the lunar surface, for its first six months of operation on the lunar surface.... We describe the photometric calibration of the Lunar-based Ultraviolet Telescope(LUT), the first robotic astronomical telescope working on the lunar surface, for its first six months of operation on the lunar surface. Two spectral datasets(set A and B) from near-ultraviolet(NUV) to the optical band were constructed with 44 International Ultraviolet Explorer(IUE) standards, because of the LUT’s relatively wide wavelength coverage. Set A was obtained by extrapolating the IUE NUV spectra(λ < 3200 ) to the optical band based upon the theoretical spectra of stellar atmosphere models. Set B was composed of theoretical spectra from 2000  to 8000 extracted from the same model grid. In total, seven standards have been observed in15 observational runs until May 2014. The calibration results show that the photometric performance of LUT is highly stable in its first six months of operation. The magnitude zero points obtained from the two spectral datasets are also consistent with each other, i.e., zp = 17.54 ± 0.09 mag(set A) and zp = 17.52 ± 0.07 mag(set B). 展开更多
关键词 天文望远镜 月球表面 紫外探测 光度性能 UV光谱 校正 光学波段 大气模型
Head Orientation Stability of Underwater Snake-like Robot Swimming 预览
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作者 Ke Yang Xuyang Wang +1 位作者 Tong Ge Chao Wu 《哈尔滨工业大学学报:英文版》 EI CAS 2015年第2期18-25,共8页
In prior research,the orientation of head of the snake-like robot is changed according to the sinusoidal wave. To solve this problem,we propose Central Pattern Generator( CPG)-based control scheme with head-controller... In prior research,the orientation of head of the snake-like robot is changed according to the sinusoidal wave. To solve this problem,we propose Central Pattern Generator( CPG)-based control scheme with head-controller to stabilize the head of the underwater snake-like robot. The advantage of the CPG-based control scheme with head-controller is that the head of the underwater snake-like robot is direct to the target orientation during swimming. The relation between CPG parameters and orientation stability of head is discussed.The adaptation of the proposed method to environment changes is tested. The influences of CPG parameters and hydrodynamic forces on the orientation offset of head are investigated. The target orientation( the input of headcontroller) with an experimental optimization is calculated through a convenient method. To prove the feasibility of the proposed methodology,the different swimming modes have been implemented in our simulation platform.The results show that the oscillation of head’s orientation is inhibited effectively,and the proposed method has strong adaptation to environment and CPG parameters changes. 展开更多
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基于碳酸酯类电解液的硒碳复合高性能锂硒电池正极材料(英文) 被引量:2
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作者 吴超 袁利霞 +4 位作者 李真 易梓琦 曾睿 李艳容 黄云辉 《中国科学:材料科学(英文版)》 CSCD 2015年第2期91-97,共7页
因为硒的高电子电导,以及和硫相近的体积能量密度,锂硒电池继锂硫电池之后受到越来越多的关注.本论文使用蔗糖作为碳源,通过水热方法合成碳球,经KOH造孔,从而得到了具有微孔结构的多孔碳球.进一步和单质硒进行热复合制备了Se/C复合材料... 因为硒的高电子电导,以及和硫相近的体积能量密度,锂硒电池继锂硫电池之后受到越来越多的关注.本论文使用蔗糖作为碳源,通过水热方法合成碳球,经KOH造孔,从而得到了具有微孔结构的多孔碳球.进一步和单质硒进行热复合制备了Se/C复合材料作为锂硒电池的正极材料,该复合材料在碳酸酯的电解液中表现出高的活性物质利用率、稳定的循环性能和良好的倍率性能.其优异的电化学性能主要得益于Se/C复合材料的电子导电能力的改善,以及硒在碳酸酯电解液中的'固-固'电极过程.本工作关于碳酸酯电解液和醚类电解液用于锂硒电池的系统研究对今后锂硒电池电解液的选择有一定的参考意义. 展开更多
低温胁迫下甜瓜幼苗叶片代谢产物含量变化的研究 预览
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作者 尚静静 田红梅 +5 位作者 刘童光 张其安 方凌 段宝慧 吴超 严加双 《农业科学与技术:英文版》 CAS 2015年第11期2462-2466,共5页
选择安徽地区主栽品种”早甜一号”为试材,幼苗3叶l心时移人光强为100μmol/(m2·s)的光照培养箱内,每天光照12h,研究昼夜低温(5℃,5℃(昼/夜))处理8d中甜瓜幼苗叶片代谢产物含量的变化。结果表明:5℃,5℃低温胁迫下... 选择安徽地区主栽品种”早甜一号”为试材,幼苗3叶l心时移人光强为100μmol/(m2·s)的光照培养箱内,每天光照12h,研究昼夜低温(5℃,5℃(昼/夜))处理8d中甜瓜幼苗叶片代谢产物含量的变化。结果表明:5℃,5℃低温胁迫下随着时间的延长H202先增加后减少.叶片膜脂过氧化产物丙二醛(MDA)的含量呈波动性增加,可溶性糖及可溶性蛋白质等代谢产物与对照相比也增加.导致这种结果的原因可能是低温胁迫影响酶的活性,随着低温处理时间延长甜瓜有受冻害的可能,从而引起代谢产物含量的变化。经过低温锻炼,测定主要代谢产物含量的变化来研究植物的生理特性,可为选育耐低温品种及设施栽培提供理论依据。 展开更多
关键词 甜瓜 低温 代谢产物 生理特性
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芯棒形式对薄壁管弯曲成形质量的影响 预览 被引量:2
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作者 吴超 严勇 胡志力 《机床与液压》 北大核心 2015年第12期52-59,共8页
薄壁管弯曲成形过程中芯棒对弯管的成形质量影响较大,芯棒形式的选取是否合理直接关系着管件成形质量的优劣。采用有限元平台ABAQUS/Explicit建立不锈钢管三维仿真模型,讨论了圆柱式、圆头式、弧式、球窝式和圆头球窝式5种形式的芯棒对... 薄壁管弯曲成形过程中芯棒对弯管的成形质量影响较大,芯棒形式的选取是否合理直接关系着管件成形质量的优劣。采用有限元平台ABAQUS/Explicit建立不锈钢管三维仿真模型,讨论了圆柱式、圆头式、弧式、球窝式和圆头球窝式5种形式的芯棒对弯管成形质量的影响,并对球窝式芯棒进行了实验验证。结果表明:在球窝式和圆头球窝式等关节式芯棒的支撑下弯曲管件的外壁减薄率比圆柱式、圆头式以及弧式芯棒等整体式芯棒高;弧式芯棒较有利于减轻管件弯曲后外壁减薄情况;球窝式芯棒有利于获得综合性能更好的成形管件;有限元仿真模型能够较可靠地模拟实际数控弯曲成形,为生产加工芯棒的选取提供了理论指导。 展开更多
关键词 薄壁管 数控弯曲 芯棒 有限元仿真
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Association of serum gamma-glutamyl transferase with treatment outcome in chronic hepatitis B patients 预览 被引量:1
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作者 RuiHuang Chen-ChenYang +8 位作者 YongLiu JuanXia RanSu Ya-LiXiong Gui-YangWang Zhen-HuaSun Xiao-MinYan ShanLu ChaoWu 《世界胃肠病学杂志:英文版》 SCIE CAS 2015年第34期9957-9965,共9页
AIM:To investigate the association of serum gammaglutamyl transferase(GGT) levels with chronic hepatitis B infection and hepatitis B e antigen(HBe Ag) seroconversion.METHODS:A retrospective study was performed on clin... AIM:To investigate the association of serum gammaglutamyl transferase(GGT) levels with chronic hepatitis B infection and hepatitis B e antigen(HBe Ag) seroconversion.METHODS:A retrospective study was performed on clinical data collected from patients who had been positive for hepatitis B surface antigen for > 6 mo and who were antiviral-treatment na?ve(n = 215) attending the Hepatitis Clinic at Nanjing Drum Tower Hospital between August 2010 and December 2013. Healthy individuals without liver disease(n = 83) were included as controls. Patients were categorized into four groups based on disease status as recommended by the European Association for the Study of the Liver:immune tolerance(IT; n = 47),HBe Ag-positive hepatitis(EPH; n = 93),HBe Ag-negative hepatitis(ENH;n = 20),and inactive carrier(IC; n = 55). Prediction of complete response(CR) based on serum GGT was also examined in EPH patients(n = 33) treated for 48 wk with nucleos(t)ide analogue(NA) therapy,including lamivudine plus adefovir combination therapy(n = 20) or entecavir monotherapy(n = 13). CR was defined as a serum hepatitis B virus DNA level < 500 copies/m L and HBe Ag seroconversion by 48 wk of treatment. RESULTS:Serum GGT levels were significantly increased in EPH and ENH patients relative to the IT,IC,and healthy control groups(P < 0.01 for all). However,no significant difference in serum GGT levels was found between the EPH and ENH groups. Baseline serum GGT levels were significantly higher in patients who achieved CR(7/33; 21.2%) compared to patients in the non-CR group(26/33; 78.8%; P = 0.011). In addition,the decline in serum GGT was greater in CR patients compared to non-CR patients after 24 wk and 48 wk of treatment(P = 0.012 and P = 0.008,respectively). The receiver operating characteristic curve yielded a sensitivity of 85.71% and a specificity of 61.54% at a threshold value of 0.89 times the upper limit of normal for baseline serum GGT in the prediction of CR following NA therapy. CONCLUSION:Serum GGT is significantly elevated in EPH a 展开更多
关键词 Gamma-glutamyl TRANSFERASE HEPATITIS B e ANTIGEN H
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基于非线性多参数融合的硫化矿石自热倾向性评价 预览
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作者 潘伟 吴超 +1 位作者 李孜军 杨月平 《中国有色金属学报:英文版》 SCIE EI CAS CSCD 2015年第2期582-589,共8页
为揭示硫化矿石非稳态自热过程的非线性动力学特征,以从某硫铁矿采集的9种硫化矿石样品为实验材料,开展室内矿石自热特性实验。采用集成小波变换、非线性特征参数提取和模糊综合评判等方法对实测温度数据进行研究。结果表明:仅矿样1... 为揭示硫化矿石非稳态自热过程的非线性动力学特征,以从某硫铁矿采集的9种硫化矿石样品为实验材料,开展室内矿石自热特性实验。采用集成小波变换、非线性特征参数提取和模糊综合评判等方法对实测温度数据进行研究。结果表明:仅矿样1、2、6和9出现明显自热,白热起始温度分别为220、239、220和220℃,在正常采矿条件下矿石不易产生自热;矿样自热过程的关联维数均为分数,最大Lyapunov指数均大于0,验证了基于混沌动力学理论研究白热过程的可行性;矿样自热过程的非线性度分别为0.8227、0.7521、0.9401和0.8827,排序依次为矿样6、矿样9、矿样1、矿样2,与自热特性测定结果一致。因此,可采用非线性度方法来评价硫化矿石白热倾向性,该方法可对实测结果的可靠性进行有效验证。 展开更多
关键词 硫化矿石 自热过程 非线性特征参数 非线性度 自热倾向性
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On the Survivability of Self-repairing Control System for a Hybrid Underwater Vehicle 预览
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作者 Biao Wang Chao Wu Tong Ge 《哈尔滨工业大学学报:英文版》 EI CAS 2014年第1期32-42,共11页
A hybrid remotely operated underwater vehicle( HROV) capable of working to the full ocean depth has been developed. In order for the vehicle to achieve a certain survivability level,a self-repairing control system( SR... A hybrid remotely operated underwater vehicle( HROV) capable of working to the full ocean depth has been developed. In order for the vehicle to achieve a certain survivability level,a self-repairing control system( SRCS) has been designed. It consists of two basic technologies,fault diagnosis and isolation( FDI) and reconfigurable control. For FDI,a model-based hierarchical fault diagnosis system is designed for the HROV. Then,control strategies which reconfigure the control system at intervals according to information from the FDI system are presented. Combining the two technologies,it can obtain the fundamental frame of SRCS for the HROV. Considering the hazardous underwater environment at the limiting depth and the hybrid operating modes,an assessment of the HROV’s survivability is vitally needed before it enters operational service. This paper presents a new definition of survivability for underwater vehicles and develops a simple survivability model for the SRCS. As a result of survivability assessment for the SRCS,we are able to figure out the survivability of SRCS and make further optimization about it. The methodology developed herein is also applicable to other types of underwater vehicles. 展开更多
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