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Accurate, First-Principle Study of Electronic and Related Properties of the Ground State of Li<sub>2</sub>Se 预览
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作者 Abdoulaye Goita Feng Gao +3 位作者 Ifeanyi H. Nwigboji Yuriy Malozovsky Lashounda Franklin Diola Bagayoko 《现代物理(英文)》 2019年第8期909-921,共13页
We present results from ab-initio, self-consistent calculations of electronic and related properties for the ground state of cubic lithium selenide (Li2Se). We employed a local density approximation (LDA) potential an... We present results from ab-initio, self-consistent calculations of electronic and related properties for the ground state of cubic lithium selenide (Li2Se). We employed a local density approximation (LDA) potential and performed computations following the Bagayoko, Zhao, and Williams (BZW) method, as enhanced by Ekuma and Franklin (BZW-EF). This method verifiably leads to the ground state of materials without employing over-complete basis sets. We present the calculated electronic energies, total and partial densities of states, effective masses, and the bulk modulus. The present calculated band structures show clearly that cubic Li2Se has a direct fundamental energy band gap of 4.065 eV at the &Gamma;point for the room temperature experimental lattice constant of 6.017 &Aring;. This result is different from findings of previous density functional theory (DFT) calculations that uniformly reported an indirect band gap, from &Gamma;to X, for Li2Se. We predicted a direct band gap of 4.363 eV, at the computationally determined equilibrium lattice constant of 5.882 &Aring;, and a bulk modulus of 35.4 GPa. For the first time known to us, we report calculated electron and hole effective masses for Li2Se. The experimental confirmation of the large, direct gap we found will point to a potential importance of this material for ultraviolet technologies and applications. Due to a lack of experimental results, most of our calculated ones in this paper are predictions for Li2Se. 展开更多
关键词 Density Functional Theory BZW-EF Method ELECTRONIC Properties Bulk MODULUS
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丁酸氧化菌群对抗生素及活性炭协同作用响应 预览
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作者 冯高 张昱晨 +1 位作者 苟敏 陈娅婷 《生物技术通报》 CAS CSCD 北大核心 2019年第8期64-76,共13页
本研究构建了以丁酸为唯一碳源的厌氧消化反应器,利用16SrRNA基因测序技术分析氯四环素(Chlortetracycline,CTC)单独抑制及CTC与颗粒活性炭(Granular active carbon,GAC)协同作用下,互营丁酸氧化微生物群落结构的动态变化,探究环境胁迫... 本研究构建了以丁酸为唯一碳源的厌氧消化反应器,利用16SrRNA基因测序技术分析氯四环素(Chlortetracycline,CTC)单独抑制及CTC与颗粒活性炭(Granular active carbon,GAC)协同作用下,互营丁酸氧化微生物群落结构的动态变化,探究环境胁迫下微生物之间的相互作用及其对CTC及CTC和GAC协同作用的响应。结果表明,原始反应器群落中,已知的互营丁酸氧化菌Syntrophomonas(11.6%)和乙酸营养型产甲烷古菌Methanosaeta(48.5%)分别在细菌和古菌群落中占主导优势。添加40mg/L和50mg/LCTC条件下,甲烷产量分别降低40.4%和49.3%。Syntrophomonas对CTC表现出耐受性,但与其呈正相关联系的细菌(如unclassified Firmicutes和unclassified Comamonadaceae)以及乙酸氧化菌Tepidanaerobacter活性被CTC明显抑制,从而影响丁酸降解率,同时造成代谢产物积累,导致产甲烷量降低。单独添加GAC以及在40mg/L和50mg/LCTC抑制下添加GAC,甲烷产量分别降低2.9%、48.5%和64.7%。共现网络分析结果显示,添加GAC明显增强了Geobacter以及与其呈正相关联系的细菌(Azonexus等)的活性。而产甲烷古菌Methanosaeta和Methanoculleus与Azonexus等大部分细菌呈负相关,因此,添加GAC可能间接影响了产甲烷古菌的活性。 展开更多
关键词 厌氧消化 互营丁酸氧化 抗生素 颗粒活性炭 种间直接电子传递
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PTPRS在食管腺癌中的表达水平及临床意义 预览
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作者 张国亮 朱奇坤 +3 位作者 曾辉 王涛 高峰 王瑞 《中国现代医学杂志》 CAS 2019年第12期27-31,共5页
目的探讨蛋白酪氨酸磷酸酶受体S(PTPRS)在食管腺癌组织中的表达及临床意义。方法应用组织芯片技术和免疫组织化学法检测71 例食管腺癌患者的癌组织、癌旁组织及食管正常黏膜中PTPRS蛋白的表达情况,分析PTPRS 蛋白与食管腺癌患者临床病... 目的探讨蛋白酪氨酸磷酸酶受体S(PTPRS)在食管腺癌组织中的表达及临床意义。方法应用组织芯片技术和免疫组织化学法检测71 例食管腺癌患者的癌组织、癌旁组织及食管正常黏膜中PTPRS蛋白的表达情况,分析PTPRS 蛋白与食管腺癌患者临床病理特征和预后的关系。结果 PTPRS 蛋白在食管腺癌组织中表达量低于食管正常黏膜组织(P <0.05)。不同临床分期、浸润深度、淋巴结转移状态、分化程度、神经受侵及脉管瘤栓的食管腺癌患者的PTPRS 蛋白表达水平比较,差异有统计学意义(P <0.05)。Kaplan-Meier 生存分析显示,PTPRS 低表达患者生存率低于高表达患者(P <0.05);多因素Cox 回归分析显示,PTPRS 为食管腺癌患者预后不良的独立危险因素[HR=2.265,(95% CI :1.050,4.887),P =0.037]。结论 PTPRS 蛋白低表达与食管腺癌患者的复发和预后密切相关。PTPRS 可能是潜在的抑癌基因,在食管癌的发生、发展中发挥重要的调控作用。 展开更多
关键词 食管腺癌 蛋白酪氨酸磷酸酶受体S 组织芯片 免疫组织化学
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Cr7C3-(Ni,Cr)3(Al,Cr)热喷涂涂层残余应力状态及其来源分析 预览
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作者 王玉 袁建鹏 +1 位作者 高峰 沈婕 《热喷涂技术》 2019年第2期68-72,共5页
采用热喷涂方法在灰铸铁基体沉积Cr7C3-(Ni,Cr)3(Al,Cr)涂层。通过X射线衍射(XRD)、扫描电子显微镜(SEM)分析涂层的形貌及结构,涂层厚度约235μm,涂层主要相成分为Cr7C3相和Ni3Al相。纳米压痕仪测定涂层硬度为16.022±2.125GPa,弹... 采用热喷涂方法在灰铸铁基体沉积Cr7C3-(Ni,Cr)3(Al,Cr)涂层。通过X射线衍射(XRD)、扫描电子显微镜(SEM)分析涂层的形貌及结构,涂层厚度约235μm,涂层主要相成分为Cr7C3相和Ni3Al相。纳米压痕仪测定涂层硬度为16.022±2.125GPa,弹性模量为247.75±16.873GPa。利用sin2ψ法分析Cr7C3相在(522)晶面在不同夹角(Ψ=0°、±9°、±18°、±27°、±36°和±45°)下的残余应力。结果表明涂层表面为残余压应力,残余应力大约为-1375.9MPa,其中本征应力为主要来源约-1267.9MPa,热应力为次要来源约-108MPa。 展开更多
关键词 热喷涂涂层 Cr7C3 残余应力
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Dendritic cell nuclear protein-1 regulates melatonin biosynthesis by binding to BMAL1 and inhibiting the transcription of N-acetyltransferase in C6 cells
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作者 Dong CHEN Yi-pei LI +7 位作者 Yan-xia YU Tian ZHOU Chao LIU Er-kang FEI Feng GAO Chen-chen MU Hai-gang REN Guang-hui WANG 《中国药理学报:英文版》 SCIE CAS CSCD 2018年第4期597-606,共10页
树枝状的房间原子 protein-1 (DCNP1 ) 是与主要消沉联系的蛋白质。在消沉病人的大脑, DCNP1 是起来调整的。然而, DCNP1 怎么参予主要消沉的致病,仍然保持未知。在这研究,我们有 EGFP-DCNP1 的第一个 transfected HEK293 房间并且... 树枝状的房间原子 protein-1 (DCNP1 ) 是与主要消沉联系的蛋白质。在消沉病人的大脑, DCNP1 是起来调整的。然而, DCNP1 怎么参予主要消沉的致病,仍然保持未知。在这研究,我们有 EGFP-DCNP1 的第一个 transfected HEK293 房间并且证明全身的 DCNP1 蛋白质在原子核是局部性的,并且 RRK (残余 117-119 ) 填写了它的原子本地化信号(NLS ) 。DCNP1 的一种 RRK 删除形式(DCNP1 <sup > RRK </sup>) 和截断的形式(缺乏 RRK 残余的 DCNP1 <sup>1-116</sup>), 各个,没在房间显示出象全身的 DCNP1 一样的特定的原子本地化。老鼠 glioma 房间线 C6 能综合 melatonin,在睡觉和消沉起重要作用的荷尔蒙。我们然后与全身的 DCNP1 然而并非 DCNP1 <sup 揭示了 C6 房间的那 transfection > RRK </sup> 或 DCNP1 <sup>1-116</sup> 显著地减少了 melatonin 的层次。而且,全身的 DCNP1 的 overexpression,然而并非 DCNP1 <sup > 在 C6 房间的 RRK </sup> 或 DCNP1 <sup>1-116</sup>, 显著地减少了 N-acetyltransferase (NAT ) 的 mRNA 和蛋白质层次,在 melatonin 的关键酶合成。全身的 DCNP1 然而并非 DCNP1 <sup > RRK </sup> 或 DCNP1 <sup>1-116</sup> 被检测与 Nat 倡导者一起交往并且通过它的电子盒子主题禁止了它的活动。而且,全身的 DCNP1 然而并非异种交往了与并且镇压 BMAL1 的 transcriptional 活动,一个抄写因素通过电子盒子主题的那 transactivates Nat。在结论,我们证明了 RRK (残余 117-119 ) 是为 DCNP1 原子本地化负责的 NLS。原子 DCNP1 镇压由与 BMAL1 交往并且镇压的 NAT 表示和 melatonin 生合成它的 transcriptional 活动。我们的学习揭示在主要消沉候选人蛋白质 DCNP1,生理节奏的系统和 melatonin 生合成之间的一个连接,它可以贡献消沉的致病。 展开更多
关键词 原子核 酶合成 树枝状 房间 调整 绑定 HEK293 蛋白质
Novel potential energy surface-based quantum dynamics of ion–molecule reaction O^++ D2→OD^++ D
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作者 王宪龙 高峰 +3 位作者 高守宝 张路路 宋玉志 孟庆田 《中国物理B:英文版》 SCIE EI CAS CSCD 2018年第4期276-280,共5页
关键词 离子分子反应 势能 动力学 CHEBYSHEV 表面 不可分 H2O 电子
EGFR TKIs联合化疗的给药顺序对NSCLC细胞促凋亡的影响 预览
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作者 高峰 张泽峰 +1 位作者 王涛 王瑞 《中国现代医学杂志》 2018年第14期24-30,共7页
目的探究表皮生长因子受体络氨酸激酶抑制剂(EGFRTKIs)与化疗药物单用、联用,以及顺序给药时,对获得性TKI耐药的非小细胞肺癌(NSCLC)细胞系凋亡的影响。方法选用存在TKI耐药基因突变(T790M,cMET)的NSCLC细胞系PC9ER、H1975和HCC827GR,以... 目的探究表皮生长因子受体络氨酸激酶抑制剂(EGFRTKIs)与化疗药物单用、联用,以及顺序给药时,对获得性TKI耐药的非小细胞肺癌(NSCLC)细胞系凋亡的影响。方法选用存在TKI耐药基因突变(T790M,cMET)的NSCLC细胞系PC9ER、H1975和HCC827GR,以及TKI敏感基因突变(19外显子突变)的细胞系PC9和HCC827。采用MTS法检测化疗药物顺铂和紫杉醇,以及TKI厄洛替尼单用、联用,或者顺序给药干预各NSCLC细胞系时的细胞活性状态,并利用集落形成试验加以验证。采用Westernblot检测各处理组蛋白裂解液中细胞凋亡标志物cPARP含量变化。结果MTS法和集落形成试验结果发现,EGFRTKIs联合化疗能协同增加NSCLC细胞系的细胞毒性。同时给予EGFRTKIs和化疗或先化疗再用EGFRTKIs,可获得最佳干预效果。Westernbolt检测结果表明,联合用药后cPARP蛋白表达升高。而且先化疗后EGFRTKIs干预比两者顺序颠倒的促凋亡作用更强。结论先化疗后EGFRTKIs干预的最优给药顺序可使对获得性TKI耐药的NSCLC细胞系产生最强的促凋亡作用。 展开更多
关键词 非小细胞肺癌 获得性耐药 化疗 表皮生长因子受体络氨酸激酶抑制剂
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特应性皮炎患者的平均血小板体积及其与瘙痒程度的关系 预览
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作者 罗浩 陈娜 +3 位作者 钟江 张衍 冯杲 吴志洪 《广西医学》 CAS 2018年第15期1645-1646,共2页
目的探讨特应性皮炎(AD)患者的平均血小板体积(MPV)及其与瘙痒程度的相关性。方法纳入110例AD患者(AD组)及50例健康体检者(正常对照组)。根据疼痛视觉模拟量表(VAS)评分将AD患者分为轻度瘙痒组39例、中度瘙痒组37例及重度瘙痒... 目的探讨特应性皮炎(AD)患者的平均血小板体积(MPV)及其与瘙痒程度的相关性。方法纳入110例AD患者(AD组)及50例健康体检者(正常对照组)。根据疼痛视觉模拟量表(VAS)评分将AD患者分为轻度瘙痒组39例、中度瘙痒组37例及重度瘙痒组34例。比较AD组与正常对照组、不同瘙痒程度组间的MPV,并分析AD患者的MPV与VAS评分的相关性。结果 AD组的血清MPV低于正常对照组(P〈0.05)。轻度瘙痒组、中度瘙痒组和重度瘙痒组MPV依次降低(P〈0.05),且AD患者MPV与VAS评分呈负相关(P〈0.05)。结论 AD患者的MPV下降,MPV可作为AD的炎症指标,其可能与AD的发生及瘙痒程度有关。 展开更多
关键词 特应性皮炎 平均血小板体积 瘙痒 视觉模拟评分法
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轧机变速箱典型故障与特征信号分析
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作者 杨帆 冯杲 焦淑军 《冶金设备》 2018年第A01期72-74,共3页
变速箱作为工业现场重要的传动设备,其运行状态必然是设备人员极为关注的,为全面、及时掌握其运行状态,本文就变速箱状态监测信号调制机理、典型故障特征及其振动信号分析进行研究,为现场变速箱的状态监测与故障诊断提供帮助。
关键词 变速箱 信号分析 常见故障
上证50ETF期权市场上的平价关系偏离 预览
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作者 夏泽宇 高峰 杨之曙 《经济学报》 2018年第4期79-102,共24页
期权平价关系是金融市场理论重要的组成部分,期权市场定价偏离平价关系的程度可以衡量期权市场的定价效率。本文从欧式期权平价关系出发,探索了上证50ETF期权市场的定价效率,发现了上证50ETF期权市场上存在相当大比例的偏离欧式平价关... 期权平价关系是金融市场理论重要的组成部分,期权市场定价偏离平价关系的程度可以衡量期权市场的定价效率。本文从欧式期权平价关系出发,探索了上证50ETF期权市场的定价效率,发现了上证50ETF期权市场上存在相当大比例的偏离欧式平价关系的情况。进一步研究发现,我国金融市场上较高的交易成本解释了其中接近一半的观测偏离,另外一半的观测偏离则主要由股票市场上缺乏有效的卖空机制来解释。除此之外,市场情绪因素也是市场偏离平价关系的重要原因,尤其是对于短到期期限的合约而言。 展开更多
关键词 期权平价关系 上证50ETF期权合约 卖空限制
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老年肩关节脱位手法复位致肱骨近端骨折的手术疗效分析 预览 被引量:2
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作者 王宇 梅继文 +3 位作者 王宏伟 穆尚强 高峰 黄锐 《中国现代医学杂志》 2018年第26期96-99,共4页
目的分析人工关节置换与内固定术对老年肩关节脱位手法复位失败致肱骨解剖颈骨折患者的疗效。方法选取2009年6月-2016年7月于吉林医药学院附属医院收治的25例老年肩关节脱位手法复位失败致肱骨解剖颈骨折患者。比较两组患者的手术时间... 目的分析人工关节置换与内固定术对老年肩关节脱位手法复位失败致肱骨解剖颈骨折患者的疗效。方法选取2009年6月-2016年7月于吉林医药学院附属医院收治的25例老年肩关节脱位手法复位失败致肱骨解剖颈骨折患者。比较两组患者的手术时间、出血量、术后并发症、肩关节Constant-Murley评分及Neer评分。结果关节置换组的手术时间、出血量、术后并发症均少于内固定组(P<0.05);两组肩关节Constant-Murley评分、Neer评分及优良率比较无差异(P>0.05)。结论人工肩关节置换治疗老年肩关节脱位手法复位失败致肱骨解剖颈骨折患者手术用时少、出血量少且术后并发症少,值得广泛推广。 展开更多
关键词 老年 肩关节脱位 肱骨解剖颈骨折 内固定 人工关节置换
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轧机变速箱典型故障与特征信号分析
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作者 杨帆 冯杲 焦淑军 《冶金设备》 2018年第S1期72-74,共3页
变速箱作为工业现场重要的传动设备,其运行状态必然是设备人员极为关注的,为全面、及时掌握其运行状态,本文就变速箱状态监测信号调制机理、典型故障特征及其振动信号分析进行研究,为现场变速箱的状态监测与故障诊断提供帮助。
关键词 变速箱 信号分析 常见故障
Sum-frequency generation in on-chip lithium niobate microdisk resonators
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作者 ZHENZHONG HAO JIE WANG +5 位作者 SHUQIONG MA WENBO MAO FANG BO FENG GAO GUOQUAN ZHANG JINGJUN XU 《光子学研究:英文版》 2017年第6期142-147,共6页
We report the first observation, to the best of our knowledge, of sum-frequency generation in on-chip lithium niobate microdisk resonators. The sum-frequency signal in the 780 nm band, distinct in wavelength from seco... We report the first observation, to the best of our knowledge, of sum-frequency generation in on-chip lithium niobate microdisk resonators. The sum-frequency signal in the 780 nm band, distinct in wavelength from secondharmonic signals, was obtained in lithium niobate microresonators under the pump of two individual 1550 nm band lasers. The sum-frequency conversion efficiency was measured to be 1.4 × 10-7 mW-1. The dependence of the intensities of the nonlinear signals on the total pump power and the wavelength of one pump laser was investigated while fixing the wavelength of the other. This work paves the way for applications of on-chip lithium niobate microdisk resonators ranging from infrared single-photon detection to infrared spectroscopy. 展开更多
A national report from China Liver Transplant Registry: steroid avoidance after liver transplantation for hepatocellular carcinoma 预览
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作者 Qiang Wei Feng Gao +8 位作者 Runzhou Zhuang Qi Ling Qinghong Ke Jian Wu Tian Shen Mangli Zhang Min Zhang Xiao Xu Shusen Zheng 《中国癌症研究:英文版》 SCIE CAS CSCD 2017年第5期426-437,共12页
Objective:We aimed to evaluate the efficacy and safety of steroid-free immunosuppression after liver transplantation(LT)for hepatocellular carcinoma(HCC).Methods:We retrospectively analyzed HCC recipients without ster... Objective:We aimed to evaluate the efficacy and safety of steroid-free immunosuppression after liver transplantation(LT)for hepatocellular carcinoma(HCC).Methods:We retrospectively analyzed HCC recipients without steroids after LT(SF group,n=368)based on the China Liver Transplant Registry(CLTR)database.These recipients were matched 1:2 with patients using steroids(S group,n=736)for the same period after LT for HCC,according to propensity scores.Results:Multivariate analysis indicates that recipients with younger age[odds ratio(OR),1.053;P=0.011],preoperative hepatitis B virus(HBV)DNA≥1,000 copies/mL(OR,2.597;P=0.004)and beyond Milan criteria(OR,4.255;P<0.001)were identified as the risk factors associated with tumor recurrence in steroid avoidance recipients after LT.The patients fulfilling the Milan criteria in the SF group presented higher overall and tumor-free survival rates than those in the S group(P<0.05).Multivariate analysis revealed that recipient beyond Milan criteria was an independent prognostic factor for overall survival(OR,1.690;P<0.001)and tumor-free survival(OR,2.066;P<0.001).The incidences of new-onset diabetes mellitus(21.20% vs.33.29%,P<0.001),new-onset hypertension(10.05%vs.18.61%,P<0.001)and hyperlipidemia(4.08% vs.7.20%,P=0.042)were significantly lower in the SF group.Conclusions:Steroid-free immunosuppression could be safe and feasible for HBV-related HCC patients in LT.Age,HBV DNA level and Milan criteria maybe risk factors associated with tumor recurrence in steroid avoidance recipients.Recipient beyond Milan criteria was an independent prognostic factor and recipient fulfilling Milan criteria can benefit the most from steroid-free immunosuppression. 展开更多
关键词 肝移植 类固醇 中国 回避 HCC 免疫力 后评估
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Controllable Biosynthesis and Properties of Gold Nanoplates Using Yeast Extract 预览
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作者 Zhi Yang Zhaohui Li +7 位作者 Xuxing Lu Fengjiao He Xingzhong Zhu Yujie Ma Rong He Feng Gao Weihai Ni Yasha Yi 《纳微快报:英文版》 CAS 2017年第1期76-88,共13页
Biosynthesis of gold nanostructures has drawn increasing concerns because of its green and sustainable synthetic process. However, biosynthesis of gold nanoplates is still a challenge because of the expensive source a... Biosynthesis of gold nanostructures has drawn increasing concerns because of its green and sustainable synthetic process. However, biosynthesis of gold nanoplates is still a challenge because of the expensive source and difficulties of controllable formation of morphology and size. Herein, one-pot biosynthesis of gold nanoplates is proposed, in which cheap yeast was extracted as a green precursor. The morphologies and sizes of the gold nanostructures can be controlled via varying the pH value of the biomedium. In acid condition, gold nanoplates with side length from 1300 ± 200 to 300 ± 100 nm and height from 18 to 15 nm were obtained by increasing the pH value. Whereas, in neutral or basic condition, only gold nanoflowers and nanoparticles were obtained. It was determined that organic molecules, such as succinic acid, lactic acid, malic acid, and glutathione, which are generated in metabolism process, played important role in the reduction of gold ions. Besides, it was found that the gold nanoplates exhibited plasmonic property with prominent dipole infrared resonance in near-infrared region, indicating their potential in surface plasmon-enhanced applications, such as bioimaging and photothermal therapy. 展开更多
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Studies on the Simultaneous Determination of Cr(Ⅲ) and Cr(Ⅵ) by Ion Chromatography(IC) 预览
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作者 Guangmin LIU Xin LIU +4 位作者 Feng GAO Na SUN Liping HU Yaqin WANG Hongju HE 《亚洲农业研究:英文版》 2017年第5期56-62,共7页
The research aimed to develop and validate an ion chromatography method for the simultaneous analysis of Cr(Ⅲ) and Cr(Ⅵ)from pumpkin. A new analytical method based on ion chromatography techniques was developed by t... The research aimed to develop and validate an ion chromatography method for the simultaneous analysis of Cr(Ⅲ) and Cr(Ⅵ)from pumpkin. A new analytical method based on ion chromatography techniques was developed by the Cr(Ⅲ) pre-column derivatization and Cr(Ⅵ) post-column derivatization. The ion chromatography condition was optimized and the detection sensitivity was improved. Cr(Ⅲ) and Cr(Ⅵ) were determined by 365 and 530 nm,respectively. The temperature of water bath,the heating time for pre-column derivatization,and the flow rate of post-column derivative liquid were screened on the basis of single factor experiment,the effects of various factors were determined by the method of L16( 43) orthogonal experiment design. Considering the results of orthogonal experiments and the variation tendency of peak area under different factors,the optimum derivatization conditions were chose as follows: the flow rate of post-column derivative liquid is0. 5 m L/min,the temperature of water bath for pre-column derivatization is 100 ℃ and the heating time is 5 min. The conditions were optimized by means of orthogonal experiments under the p H of leacheate ranged from 6. 5 to 6. 8 and the I-concentration of 5 mmol/L. Under optimized derivatization conditions,the detection limits for Cr(Ⅲ) and Cr(Ⅵ) were 0. 17 and 0. 019 mg,respectively. And the average recoveries of Cr(Ⅲ) in pumpkin were in the range of 82%-85%. Results indicated that pumpkin does not contain Cr(Ⅵ) according to this ion chromatography method of simultaneously determination for Cr(Ⅲ) and Cr(Ⅵ). 展开更多
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Recent advances in preparation,properties and device applications of twodimensional h-BN and its vertical heterostructures
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作者 Huihui Yang Feng Gao +3 位作者 Mingjin Dai Dechang Jia Yu Zhou Pingan Hu 《半导体学报:英文版》 EI CAS CSCD 2017年第3期25-43,共19页
Two-dimensional(2D) layered materials,such as graphene,hexagonal boron nitride(h-BN),molybdenum disulfide(Mo S_2/,have attracted tremendous interest due to their atom-thickness structures and excellent physical proper... Two-dimensional(2D) layered materials,such as graphene,hexagonal boron nitride(h-BN),molybdenum disulfide(Mo S_2/,have attracted tremendous interest due to their atom-thickness structures and excellent physical properties.h-BN has predominant advantages as the dielectric substrate in FET devices due to its outstanding properties such as chemically inert surface,being free of dangling bonds and surface charge traps,especially the large-band-gap insulativity.h-BN involved vertical heterostructures have been widely exploited during the past few years.Such heterostructures adopting h-BN as dielectric layers exhibit enhanced electronic performance,and provide further possibilities for device engineering.Besides,a series of intriguing physical phenomena are observed in certain vertical heterostructures,such as superlattice potential induced replication of Dirac points,band gap tuning,Hofstadter butterfly states,gate-dependent pseudospin mixing.Herein we focus on the rapid developments of h-BN synthesis and fabrication of vertical heterostructures devices based on h-BN,and review the novel properties as well as the potential applications of the heterostructures composed of h-BN. 展开更多
能源互联网的发展现状与展望 被引量:36
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作者 周孝信 曾嵘 +1 位作者 高峰 屈鲁 《中国科学:信息科学》 CSCD 北大核心 2017年第2期149-170,共22页
能源互联网是以可再生能源为优先,以电力能源为基础,多种能源协同、供给与消费协同、集中式与分布式协同,大众广泛参与的新型生态化能源系统.本文探讨了能源互联网的研究背景和意义;剖析了能源互联网的基本内涵;梳理了国内外能源互联网... 能源互联网是以可再生能源为优先,以电力能源为基础,多种能源协同、供给与消费协同、集中式与分布式协同,大众广泛参与的新型生态化能源系统.本文探讨了能源互联网的研究背景和意义;剖析了能源互联网的基本内涵;梳理了国内外能源互联网的发展动态与现状;阐述了能源互联网需重点研究的科学技术问题;展望了能源互联网的发展前景.在互联网理念、先进信息技术与能源产业深度融合的基础上,通过多能协同的能源网络、信息物理融合的能源系统、创新模式的能源运营,实现绿色、协调、高效发展,带动经济增长,支撑能源革命. 展开更多
关键词 互联网+ 能源革命 能源互联网 多能协同 信息物理系统
吸毒患者胃镜检查的丙泊酚麻醉效果观察 预览 被引量:3
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作者 高峰 《中国现代医学杂志》 北大核心 2017年第26期102-105,共4页
目的 分析丙泊酚用于吸毒患者胃镜检查的现状。方法 选取2011年11月-2017年6月该院消化科门诊及急诊收治的需接受胃镜检查的吸毒吞食异物患者42例,随机分为观察组(丙泊酚麻醉)和对照组(非麻醉),观察两组患者循环及呼吸系统相关各项... 目的 分析丙泊酚用于吸毒患者胃镜检查的现状。方法 选取2011年11月-2017年6月该院消化科门诊及急诊收治的需接受胃镜检查的吸毒吞食异物患者42例,随机分为观察组(丙泊酚麻醉)和对照组(非麻醉),观察两组患者循环及呼吸系统相关各项指标,对比两组患者手术时间、出现插管失败需拔管情况,以及与手术操作、麻醉用药相关的不良反应、手术耐受情况。结果 观察组患者的耐受率为90.48%,高于对照组的4.76%(P〈0.05)。观察组患者心率及呼吸频率在T1、T2和T3时间的波动幅度小于对照组。观察组患者胃镜手术操作时间为(5.36±2.02)min,对照组操作时间为(8.84±1.97)min,观察组患者手术时较短(P〈0.05);观察组患者拔管率为0.00%,低于对照组的28.57%(P〈0.05)。两组患者的高血压、低血压、心动过速、心动过缓、呼吸抑制发生率比较,差异无统计学意义(P〉0.05),观察组患者戒断反应发生率低于对照组(P〈0.05)。结论 丙泊酚用于吸毒患者的胃镜麻醉效果较好,麻醉过程中患者自觉不适感低,耐受性佳,安全性有保障,值得临床推广应用。 展开更多
关键词 丙泊酚 吸毒患者 胃镜麻醉 耐受性 安全性
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Imprints of relic gravitational waves on pulsar timing
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作者 Ming-Lei Tong Yong-Heng Ding +4 位作者 Cheng-Shi Zhao Feng Gao Bao-Rong Yan Ting-Gao Yang Yu-Ping Gao 《天文和天体物理学研究:英文版》 SCIE CAS CSCD 2016年第3期111-120,共10页
Relic gravitational waves(RGWs), a background originating during inflation, would leave imprints on pulsar timing residuals. This makes RGWs an important source for detection of RGWs using the method of pulsar timing.... Relic gravitational waves(RGWs), a background originating during inflation, would leave imprints on pulsar timing residuals. This makes RGWs an important source for detection of RGWs using the method of pulsar timing. In this paper, we discuss the effects of RGWs on single pulsar timing, and quantitatively analyze the timing residuals caused by RGWs with different model parameters. In principle, if the RGWs are strong enough today, they can be detected by timing a single millisecond pulsar with high precision after the intrinsic red noises in pulsar timing residuals are understood, even though simultaneously observing multiple millisecond pulsars is a more powerful technique for extracting gravitational wave signals. We correct the normalization of RGWs using observations of the cosmic microwave background(CMB), which leads to the amplitudes of RGWs being reduced by two orders of magnitude or so compared to our previous works. We obtained new constraints on RGWs using recent observations from the Parkes Pulsar Timing Array, employing the tensor-to-scalar ratio r = 0.2 due to the tensor-type polarization observations of CMB by BICEP2 as a reference value, even though its reliability has been brought into question. Moreover, the constraints on RGWs from CMB and Big Bang nucleosynthesis will also be discussed for comparison. 展开更多
关键词 脉冲星计时 引力波 印记 遗迹 宇宙微波背景辐射 毫秒脉冲星 时序残差 通货膨胀
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