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Assessing recent recurrence after hepatectomy for hepatitis Brelated hepatocellular carcinoma by a predictive model based on sarcopenia
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作者 Hong Peng Si-Yi Lei +9 位作者 Wei Fan yu dai Yi Zhang Gen Chen Ting-Ting Xiong Tian-Zhao Liu yue Huang Xiao-Feng Wang Jin-Hui Xu Xin-Hua Luo 《World Journal of Gastroenterology》 SCIE CAS 2024年第12期1727-1738,共12页
BACKGROUND Sarcopenia may be associated with hepatocellular carcinoma(HCC)following hepatectomy.But traditional single clinical variables are still insufficient to predict recurrence.We still lack effective prediction... BACKGROUND Sarcopenia may be associated with hepatocellular carcinoma(HCC)following hepatectomy.But traditional single clinical variables are still insufficient to predict recurrence.We still lack effective prediction models for recent recurrence(time to recurrence<2 years)after hepatectomy for HCC.AIM To establish an interventable prediction model to estimate recurrence-free survival(RFS)after hepatectomy for HCC based on sarcopenia.METHODS We retrospectively analyzed 283 hepatitis B-related HCC patients who underwent curative hepatectomy for the first time,and the skeletal muscle index at the third lumbar spine was measured by preoperative computed tomography.94 of these patients were enrolled for external validation.Cox multivariate analysis was per-formed to identify the risk factors of postoperative recurrence in training cohort.A nomogram model was developed to predict the RFS of HCC patients,and its predictive performance was validated.The predictive efficacy of this model was evaluated using the receiver operating characteristic curve.RESULTS Multivariate analysis showed that sarcopenia[Hazard ratio(HR)=1.767,95%CI:1.166-2.678,P<0.05],alpha-fetoprotein≥40 ng/mL(HR=1.984,95%CI:1.307-3.011,P<0.05),the maximum diameter of tumor>5 cm(HR=2.222,95%CI:1.285-3.842,P<0.05),and hepatitis B virus DNA level≥2000 IU/mL(HR=2.1,95%CI:1.407-3.135,P<0.05)were independent risk factors associated with postoperative recurrence of HCC.Based on the sarcopenia to assess the RFS model of hepatectomy with hepatitis B-related liver cancer disease(SAMD)was established combined with other the above risk factors.The area under the curve of the SAMD model was 0.782(95%CI:0.705-0.858)in the training cohort(sensitivity 81%,specificity 63%)and 0.773(95%CI:0.707-0.838)in the validation cohort.Besides,a SAMD score≥110 was better to distinguish the high-risk group of postoperative recurrence of HCC.CONCLUSION Sarcopenia is associated with recent recurrence after hepatectomy for hepatitis B-related HCC.A nutritional status-based prediction model is first established for postoperative recurrence of hepatitis B-related HCC,which is superior to other models and contributes to prognosis prediction. 展开更多
关键词 ALPHA-FETOPROTEIN Hepatitis B virus HEPATECTOMY Hepatocellular carcinoma NOMOGRAM Predictive models RECURRENCE Recurrence-free survival Risk factors SARCOPENIA
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Development of a monochromatic crystal backlight imager for the recent double-cone ignition experiments
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作者 张成龙 张翌航 +11 位作者 远晓辉 张喆 徐妙华 戴羽 董玉峰 谷昊琛 刘正东 赵旭 李玉同 李英骏 朱健强 张杰 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期40-45,共6页
We developed a monochromatic crystal backlight imaging system for the double-cone ignition(DCI) scheme, employing a spherically bent quartz crystal. This system was used to measure the spatial distribution and tempora... We developed a monochromatic crystal backlight imaging system for the double-cone ignition(DCI) scheme, employing a spherically bent quartz crystal. This system was used to measure the spatial distribution and temporal evolution of the head-on colliding plasma from the two compressing cones in the DCI experiments. The influence of laser parameters on the x-ray backlighter intensity and spatial resolution of the imaging system was investigated. The imaging system had a spatial resolution of 10 μm when employing a CCD detector. Experiments demonstrated that the system can obtain time-resolved radiographic images with high quality, enabling the precise measurement of the shape, size, and density distribution of the plasma. 展开更多
关键词 double-cone ignition(DCI) spatial resolution x-ray radiography
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透明AlON陶瓷的发展现状和挑战 被引量:2
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作者 吴建 王卓健 +4 位作者 胡智臣 刘兴亮 谭敦强 戴煜 耿东生 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2023年第3期653-667,共15页
氮氧化铝透明陶瓷是备受关注的材料,广泛应用于商业和军事领域,如红外和可见光窗口、透明装甲等方面。最近几年,氮氧化铝透明陶瓷得到了快速发展,出现新的制备方法、新的烧结助剂及新的应用领域。然而,目前还没有系统的、最新的相关综... 氮氧化铝透明陶瓷是备受关注的材料,广泛应用于商业和军事领域,如红外和可见光窗口、透明装甲等方面。最近几年,氮氧化铝透明陶瓷得到了快速发展,出现新的制备方法、新的烧结助剂及新的应用领域。然而,目前还没有系统的、最新的相关综述。此外,氮氧化铝透明陶瓷还存在一些未解决的问题和新的挑战,严重阻碍其商业化应用。因此,本文作者全面介绍氮氧化铝陶瓷的制备方法,包括高温固相反应法、氧化铝还原氮化法、化学气相沉积法和溶胶凝胶等方法,并对这些制备方法的优缺点进行比较分析。此外,系统地总结烧结助剂和烧结工艺对氮氧化铝透明陶瓷透光性的影响。最后,对氮氧化铝透明陶瓷面临的挑战和发展趋势进行讨论和展望。 展开更多
关键词 透明氮氧化铝陶瓷 Al_(2)O_(3)-AlN二元体系 氧化钇烧结助剂
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石墨相氮化碳光催化还原CO_(2)研究进展 被引量:3
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作者 常世鑫 虞梦雪 +3 位作者 俞迨 严翼 王之 吕康乐 《中南民族大学学报(自然科学版)》 CAS 北大核心 2023年第6期721-732,共12页
半导体光催化可以利用太阳能驱动CO_(2)光催化还原制备碳氢燃料,成为研究热点.石墨相氮化碳(g-C_(3)N_(4))具有制备简便和可见光响应性能的优点,是CO_(2)还原的热门光催化材料。但是它具有缺陷多、比表面积小和光生载流子易复合等缺点,... 半导体光催化可以利用太阳能驱动CO_(2)光催化还原制备碳氢燃料,成为研究热点.石墨相氮化碳(g-C_(3)N_(4))具有制备简便和可见光响应性能的优点,是CO_(2)还原的热门光催化材料。但是它具有缺陷多、比表面积小和光生载流子易复合等缺点,光催化CO_(2)还原性能不高.为此,介绍了高CO_(2)还原活性的g-C_(3)N_(4)研究进展,内容包括:(1)g-C_(3)N_(4)研究基础(分子结构、制备方法与电子能带结构);(2)高活性g-C_(3)N_(4)的分子设计策略(缺陷调控、元素掺杂、表面等离子体处理、单原子催化和异质结构建等),重点讨论了改性方式对g-C_(3)N_(4)的光吸收、光电性能和CO_(2)还原产物选择性的影响.最后建议未来聚焦结晶氮化碳的修饰改性研究,强调利用原位和瞬态表征技术指导高CO_(2)还原活性的gC_(3)N_(4)的开发,并关注具有高能量密度的长链碳氢燃料产物的选择性. 展开更多
关键词 氮化碳 光催化 CO_(2)还原 选择性
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局部氧自由基的性质促进电催化乙醇选择性生成CO_(2)
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作者 周双龙 赵亮 +4 位作者 吕征 代钰 张琦 赖建平 王磊 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2023年第9期154-163,共10页
碱性燃料电池可以避免卡诺循环效应的限制,因而被认为是最具有发展潜力的能源转换器件之一.与其它燃料相比,乙醇来源丰富,储存和运输成本较低,更适合作为燃料电池的能量来源.但在乙醇氧化反应(EOR)过程中,通常发生2个或6个电子转移的不... 碱性燃料电池可以避免卡诺循环效应的限制,因而被认为是最具有发展潜力的能源转换器件之一.与其它燃料相比,乙醇来源丰富,储存和运输成本较低,更适合作为燃料电池的能量来源.但在乙醇氧化反应(EOR)过程中,通常发生2个或6个电子转移的不完全氧化反应,而不是转移12个电子的完全氧化过程.除催化剂对C-C键裂解能力较低外,中间体对催化剂的毒化也是造成乙醇不能被完全氧化的原因.大量研究表明,增强催化剂对OH*和O*的吸附可以有效促进C-C键的裂解并提高催化剂的抗毒化性能.然而,不同氧物种对C-C键裂解的作用尚不明确.本文将人工氧化酶应用在EOR中,并在此基础上探究了不同氧自由基在乙醇氧化过程中的作用.本文发现一种可以催化氧气原位生成活性氧物种(ROS)的人工氧化酶,并利用该特点,将人工氧化酶应用于EOR中,同时探究了不同ROS在乙醇完全氧化中的作用.当没有ROS时,催化剂的质量活性为7.6 A mg_(Pt)^(-1),二氧化碳的法拉第效率仅为12.4%;而在ROS的作用下,催化剂的质量活性可以达到18.2 A mg_(Pt)^(-1),二氧化碳的法拉第效率达到98.7%.这说明ROS的存在有助于提升催化剂活性和二氧化碳选择性.与PtSn IM/C相比,商业Pt/C只能生成少量的羟基自由基,没有检测到单线态氧和超氧阴离子,表明Sn元素的引入可以优化Pt的电子结构,并改善催化剂的表面配位方式,提高催化剂的氧化酶活性.利用原位红外测试技术研究了反应过程中生成的中间体和催化剂整体性能,结果表明,在ROS作用下催化剂表面没有生成有毒的*CO中间体,说明ROS显著提升了催化剂的抗毒化性能.另外,经过8次电解液的更新,二氧化碳的选择性没有发生明显衰减,表明ROS可以增强催化剂的耐久性.CO剥离实验结果表明,在ROS的作用下,催化剂对CO的氧化电位降低了46mV,进一步证明ROS可以有效避免催化剂被中间产物毒化.为进一步研究反应的机理,对体系中生成的ROS进行了电子顺磁共振测试.结果表明,PtSn IM/C可以催化氧气原位生成大量的·OH,·O_(2)~-和~1O_(2).通过向体系中加入不同的自由基捕获剂探究不同氧物种对EOR活性和C-C键裂解的影响.结果表明,单线态氧可以显著提升催化剂活性和C-C键的裂解能力.理论计算结果表明,*CH_(3)CO的C-C键断裂产生*CH_(3)和*CO是Cl途径的决速步骤.当单线态氧存在于PtSn IM/C表面上时,C-C键的离解能为-0.51 eV,低于羟基自由基的1.07 eV和超氧阴离子的-0.47 eV.综上所述,乙醇燃料电池是未来最具有潜力的能源转换器件之一.本研究为乙醇燃料电池阳极催化剂的设计提供了一种新思路.本研究还为探究氧自由基在乙醇氧化反应中的作用和用于多元醇完全氧化反应的催化剂的制备提供参考. 展开更多
关键词 乙醇 高性能 离解能 自由基
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Ultrafast two-dimensional x-ray imager with temporal fiducial pulses for laser-produced plasmas
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作者 刘正东 仲佳勇 +21 位作者 远晓辉 张雅芃 姚嘉文 马作霖 徐向晏 薛彦华 张喆 袁大伟 张敏睿 李炳均 谷昊琛 戴羽 张成龙 董玉峰 周鹏 马鑫杰 马云峰 白雪洁 刘高扬 田进寿 赵刚 张杰 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第11期214-219,共6页
It is challenging to make an ultrafast diagnosis of the temporal evolution of small and short-lived plasma in two dimensions. To overcome this difficulty, we have developed a well-timed diagnostic utilizing an x-ray s... It is challenging to make an ultrafast diagnosis of the temporal evolution of small and short-lived plasma in two dimensions. To overcome this difficulty, we have developed a well-timed diagnostic utilizing an x-ray streak camera equipped with a row of multi-pinhole arrays. By processing multiple sets of one-dimensional streaked image data acquired from various pinholes, we are capable of reconstructing high-resolution two-dimensional images with a temporal resolution of 38 ps and a spatial resolution of 18 μm. The temporal fiducial pulses accessed from external sources can advance the precise timing and accurately determine the arrival time of the laser. Moreover, it can correct the nonlinear sweeping speed of the streak camera. The effectiveness of this diagnostic has been successfully verified at the Shenguang-II laser facility,providing an indispensable tool for observing complex physical phenomena, such as the implosion process of laser-fusion experiments. 展开更多
关键词 ultrafast diagnosis double-cone ignition x-ray streak camera pinhole array temporal fiducial pulses
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Nacre-inspired interface structure design of polymer bonded explosives toward significantly enhanced mechanical performance
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作者 Peng Wang You-long Chen +6 位作者 Li Meng Yin-shuang Sun yu dai Xin Li Jie Chen Zhi-jian Yang Guan-song He 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第9期83-92,共10页
Realizing effective enhancement to the structure of interface region between explosive crystals and polymer binder plays a key role in improving the mechanical properties of the current polymer bonded explosives(PBXs)... Realizing effective enhancement to the structure of interface region between explosive crystals and polymer binder plays a key role in improving the mechanical properties of the current polymer bonded explosives(PBXs).Herein,inspired by the structure of natural nacre which possesses outstanding mechanical performance,a kind of nacre-like structural layer is constructed in the interface region of PBXs composites,making use of two-dimensional graphene sheets and one-dimensional bio-macromolecules of cellulose as inorganic and organic building blocks,respectively.Our results reveal that the constructed nacre-like structural layer can effectively improve the interfacial strength and then endow the PBXs composites with significantly enhanced mechanical properties involving of creep resistance,Brazilian strength and fracture toughness,demonstrating the obvious advantage of such bioinspired interface structure design strategy.In addition,the thermal conduction performance of PBXs composites also exhibits noticeable enhancement due to the remarkable phonon transport capability endowed by the asdesigned nacre-like structural layer.We believe this work provides a novel design route to conquer the issue of weak interfacial strength in PBXs composites and greatly increase the comprehensive properties for better meeting the higher requirements proposed to the explosive part of weapon equipment in new era. 展开更多
关键词 Polymer bonded explosives Nacre-like structural layer GRAPHENE CELLULOSE Mechanical properties
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Development of Henoch-Schoenlein purpura in a child with idiopathic hypereosinophilia syndrome with multiple thrombotic onset: A case report
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作者 Yan-Yan Xu Xiao-Bi Huang +4 位作者 yun-Gong Wang Li-yun Zheng Min Li yu dai Sheng Zhao 《World Journal of Clinical Cases》 SCIE 2023年第4期952-961,共10页
BACKGROUND The incidence of pulmonary embolism(PE) in children is low, but its mortality is high. Hypereosinophilic syndrome(HES) is a group of diseases caused by an abnormal increase in eosinophilic granulocytes resu... BACKGROUND The incidence of pulmonary embolism(PE) in children is low, but its mortality is high. Hypereosinophilic syndrome(HES) is a group of diseases caused by an abnormal increase in eosinophilic granulocytes resulting in multiple-organ dysfunction. The urgent event of thromboembolism in the pulmonary region provoked by eosinophils in idiopathic HES(IHES) is relatively unusual. This article reports a case of IHES with multiple PEs and left leg venous thrombosis as the first manifestation. One month later, the patient developed Henoch-Schonlein purpura(HSP), which is very rare.CASE SUMMARY We report the case of a 12-year-old boy who was admitted to the hospital with dyspnea, left leg pain, and aggravation. He had bilateral PE and left leg venous embolism with mild eosinophilia. Low-molecular-weight heparin and urokinase were given. At the same time, the interventional department was contacted about filter implantation, followed by urokinase thrombolysis. The left leg thrombus was aspirated under ultrasound guidance. He was discharged from the hospital on rivaroxaban. One month later, he developed a rash on both legs and ankle pain consistent with HSP, with severe eosinophilia and motor and sensory disturbances. The patient was diagnosed with IHES with multiple embolisms complicated by HSP after excluding other causes of the eosinophil elevation. After glucocorticoid treatment, the symptoms were relieved, but the patient later developed purpura nephritis.CONCLUSION We report a rare and life-threatening case of IHES with multiple embolisms associated with HSP.A mild elevation of eosinophils early in the disease leads to difficulties in diagnosis and delayed treatment. 展开更多
关键词 EOSINOPHIL Hypereosinophilic syndrome Henoch-Schoenlein purpura THROMBOSIS Case report
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The prospects for bioprinting tumor models:recent advances in their applications
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作者 Changru Zhang Xiaoqin Qiu +10 位作者 yu dai Weiqing Kong Yihao Liu Haoyi Niu Chengwei Wang Xuelian Mi Hui Wang Ya Ren Han Yang Kerong dai Jinwu Wang 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2023年第6期661-675,共15页
Three-dimensional(3D)tumor models prepared from patient-derived cells have been reported to imitate some of the biological development processes of in situ tumors in vitro.These 3D tumor models share several important... Three-dimensional(3D)tumor models prepared from patient-derived cells have been reported to imitate some of the biological development processes of in situ tumors in vitro.These 3D tumor models share several important characteristics with their in vivo tumor counterparts.Accordingly,their applications in tumor modeling,drug screening,and precision-targeted treatment are promising.However,the establishment of tumormodels is subject to several challenges,including advancements in scale size,repeatability,structural precision in time and space,vascularization,and the tumor microenvironment.Recently,bioprinting technologies enabling the editorial arrangement of cells,factors,and materials have improved the simulation of tumormodels in vitro.Among the 3D bioprinted tumor models,the organoidmodel has been widely appreciated for its advantages of maintaining high heterogeneity and capacity for simulating the developmental process of tumor tissues.In this review,we outline approaches and potential prospects for tumor model bioprinting and discuss the existing bioprinting technologies and bioinks in tumor model construction.The multidisciplinary combination of tumor pathology,molecular biology,material science,and additive manufacturing will help overcome the barriers to tumor model construction by allowing consideration of the structural and functional characteristics of in vitro models and promoting the development of heterogeneous tumor precision therapies. 展开更多
关键词 BIOPRINTING Tissue engineering Tumor organoid
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Study on the Effects of Helium-Argon Gas Mixture on the Laser Welding Performance of High Temperature Alloys
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作者 Xiongzi CHEN Hesi PENG +2 位作者 Chunchen YAO yu dai Yewen QIN 《Research and Application of Materials Science》 2023年第2期21-24,共4页
In order to solve the problem of porosity in laser deep penetration welding of GH3625 high-temperature alloy plates,five different ratios of high-purity helium gas and high-purity argon gas mixed gases were compared i... In order to solve the problem of porosity in laser deep penetration welding of GH3625 high-temperature alloy plates,five different ratios of high-purity helium gas and high-purity argon gas mixed gases were compared in welding experiments after various process parameter improvements and adjustments failed to achieve Class I welds.The experimental results show that using high-purity helium gas or a mixture of 50%high-purity helium gas and 50%high-purity argon gas can both achieve Class I welds.This indicates that using high-purity helium gas or an appropriate mixed gas instead of pure argon is one of the effective ways to solve the problem of porosity in laser deep penetration welding of high-temperature alloys.The mixture of 50%high-purity argon gas and 50%high-purity helium gas can reduce the consumption of high-purity helium gas,lower production costs,and is more suitable. 展开更多
关键词 high-temperature alloy laser welding pores shielding gas welding quality
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井间地震高斯束叠前深度偏移成像方法 被引量:4
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作者 俞岱 杨飞龙 +2 位作者 孙渊 边瑞峰 王颖 《物探化探计算技术》 CAS CSCD 2018年第2期141-149,共9页
井间地震成像技术在解决复杂构造、油藏描述等方面具有较高的成像精度。高斯束偏移成像方法兼具Kirchhoff积分偏移的灵活性以及波动方程偏移的精确性,不仅计算速度快,并且运算精度高。在地面地震高斯束叠前深度偏移成像方法研究的基础上... 井间地震成像技术在解决复杂构造、油藏描述等方面具有较高的成像精度。高斯束偏移成像方法兼具Kirchhoff积分偏移的灵活性以及波动方程偏移的精确性,不仅计算速度快,并且运算精度高。在地面地震高斯束叠前深度偏移成像方法研究的基础上,首次将其应用于井间地震资料成像。针对井间理论模型试算,同井间地震波动方程逆时偏成像方法相比,井间地震高斯束叠前深度偏移方法成像精确,计算效率高。将该方法应用在某海上油田井间地震资料成像中,这里所研究的井间地震高斯束叠前深度偏移成像方法的成像结果,比海上三维地震剖面具有更高的分辨率,解决了海上三维地震分辨率不足的难题,可为油气田目的层微小构造识别提供有利依据,具有较好的应用前景。 展开更多
关键词 井间地震 高斯射线束 叠前偏移 成像
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基于多t-x域联合的多震源地震数据混叠噪声分离方法 被引量:1
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作者 俞岱 黄德智 +1 位作者 孙渊 杨文平 《煤田地质与勘探》 CAS CSCD 北大核心 2021年第5期209-219,共11页
随着多震源同时激发采集方法在地震油气勘探领域的应用逐年增加,许多学者对其关键技术多震源地震数据混叠噪声分离进行了研究,就目前为止,仍需开展保真度更高的方法研究。基于以下设想:对多震源地震数据做正常时差校正(NMO),可以加强反... 随着多震源同时激发采集方法在地震油气勘探领域的应用逐年增加,许多学者对其关键技术多震源地震数据混叠噪声分离进行了研究,就目前为止,仍需开展保真度更高的方法研究。基于以下设想:对多震源地震数据做正常时差校正(NMO),可以加强反射信号的线性分布程度(尤其在共中心点CMP道集内),并扩大反射信号和混叠噪声的分布差异;单域分离混叠噪声,仅针对混叠噪声和反射信号的某一分布特性差异进行分离,多t-x域联合分离可综合利用各t-x域内混叠噪声和反射信号在各域内的分布差异,其分离效果更好。首先,通过对多震源数据CMP道集做NMO以强化反射信号的线性程度、扩大随机分布混叠噪声的离散程度,利用中值滤波分离大部分混叠噪声,再在其他t-x域内(如共炮点CSG道集、共检波点CRG道集和共偏移距COG道集等)根据残余混叠噪声分布特征利用随机噪声衰减等方法进一步分离,并在整个分离处理中使用保幅处理方法。提出的多t-x域联合分离混叠噪声方法,经理论数据验证,相较于单域分离方法可以有效且保真分离多震源数据中的混叠噪声,并对其他噪声和横波有一定的压制作用;实际数据应用效果表明,该方法比单域方法分离效果较好,叠后成像效果品质较高。多t-x域联合分离混叠噪声方法,能够稳定、可靠和保真地分离多震源地震数据中的混叠噪声。 展开更多
关键词 多震源地震采集 混叠噪声分离 多t-x域联合 噪声离散化
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经济增长、金融发展、对外贸易与能源消费动态关系研究 被引量:6
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作者 戴钰 刘亦文 《经济数学》 2018年第2期50-57,共8页
基于我国1978-2013年的统计数据,运用ARDL边限协整检验技术和VECM格兰杰因果检验方法,对经济增长、金融发展、对外贸易与能源消费之间的关系进行了系统地研究.实证结果表明,经济增长、金融发展、对外贸易与能源消费之间存在长期协整关系... 基于我国1978-2013年的统计数据,运用ARDL边限协整检验技术和VECM格兰杰因果检验方法,对经济增长、金融发展、对外贸易与能源消费之间的关系进行了系统地研究.实证结果表明,经济增长、金融发展、对外贸易与能源消费之间存在长期协整关系.经济增长和能源消费不满足EKC假设,两者之间呈现正"U"型变化,目前我国经济位于曲线右边,即能源消费随着经济的增长而增加.金融发展对能源消费存在显著的正向效应,对外贸易的发展也会增加能源消费.格兰杰因果检验表明存在从经济增长到能源消费、金融发展和对外贸易的单向因果关系.金融发展和能源消费之间存在长期双向因果关系,同样的,这种关系也被发现在对外贸易和能源消费、金融发展和对外贸易之间. 展开更多
关键词 经济增长 金融发展 对外贸易 能源消费
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基于压缩感知的复杂地表菲涅尔束偏移 被引量:1
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作者 杨飞龙 俞岱 孙渊 《物探与化探》 CAS 北大核心 2019年第6期1285-1290,共6页
高斯束偏移是一种束类地震数据成像方法,该方法可以处理多波至走时,具有良好的成像精度。但在复杂地表条件下应用存在两个问题:一是原有的局部平面波分解方法计算精度不足,影响低信噪比数据成像质量;二是偏移精度取决于射线束传播算子,... 高斯束偏移是一种束类地震数据成像方法,该方法可以处理多波至走时,具有良好的成像精度。但在复杂地表条件下应用存在两个问题:一是原有的局部平面波分解方法计算精度不足,影响低信噪比数据成像质量;二是偏移精度取决于射线束传播算子,高斯束传播算子随着传播距离增大发散过快,难以同时保证浅层和中深层构造成像精度,并且高斯束射线传播算子在模型浅部覆盖范围不足,对复杂地表模型成像精度较低。为了解决上述问题,本文将基于压缩感知理论的平面波分解技术应用到复杂地表菲涅尔束偏移中,不仅有效提高了局部平面波分解精度,同时菲涅尔束传播算子有效解决了高斯束算子随传播距离增加束宽发散过大的问题,典型的模型算例验证了本文方法的有效性和稳定性。 展开更多
关键词 高斯束 压缩感知 菲涅尔束偏移 复杂地表 局部平面波分解 束算子
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Models for predicting hepatitis B e antigen seroconversion in response to interferon-α in chronic hepatitis B patients 被引量:12
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作者 Chang-Tai Wang Ya-Fei Zhang +7 位作者 Bing-Hu Sun yu dai Hui-Lan Zhu yuan-Hong Xu Meng-Ji Lu Dong-Liang Yang Xu Li Zhen-Hua Zhang 《World Journal of Gastroenterology》 SCIE CAS 2015年第18期5668-5676,共9页
AIM:To develop models to predict hepatitis B e antigen(HBe Ag)seroconversion in response to interferon(IFN)-αtreatment in chronic hepatitis B patients.METHODS:We enrolled 147 treatment-nave HBe Agpositive chronic h... AIM:To develop models to predict hepatitis B e antigen(HBe Ag)seroconversion in response to interferon(IFN)-αtreatment in chronic hepatitis B patients.METHODS:We enrolled 147 treatment-nave HBe Agpositive chronic hepatitis B patients in China and analyzed variables after initiating IFN-α1b treatment.Patients were tested for serum alanine aminotransferase(ALT),hepatitis B virus-DNA,hepatitis B surface antigen(HBs Ag),antibody to hepatitis B surface antigen,HBe Ag,antibody to hepatitis B e antigen(anti-HBe),and antibody to hepatitis B core antigen(anti-HBc)at baseline and 12 wk,24 wk,and 52 wk after initiating treatment.We performed univariate analysis to identify response predictors among the variables.Multivariate models to predict treatment response were constructed at baseline,12 wk,and 24 wk.RESULTS:At baseline,the 3 factors correlating most with HBe Ag seroconversion were serum ALT level>4×the upper limit of normal(ULN),HBe Ag≤500 S/CO,and anti-HBc>11.4 S/CO.At 12 wk,the 3 factors most associated with HBe Ag seroconversion were HBe Ag level≤250 S/CO,decline in HBe Ag>1 log10 S/CO,and anti-HBc>11.8 S/CO.At 24 wk,the 3 factors most associated with HBe Ag seroconversion were HBe Ag level≤5 S/CO,anti-HBc>11.4 S/CO,and decline in HBe Ag>2 log10 S/CO.Each variable was assigned a score of1,a score of 0 was given if patients did not have any of the 3 variables.The 3 factors most strongly correlating with HBe Ag seroconversion at each time point were used to build models to predict the outcome after IFN-αtreatment.When the score was 3,the response rates at the 3 time points were 57.7%,83.3%,and 84.0%,respectively.When the score was 0,the response rates were 2.9%,0.0%,and 2.1%,respectively.CONCLUSION:Models with good negative and positive predictive values were developed to calculate the probability of response to IFN-αtherapy. 展开更多
关键词 CHRONIC HEPATITIS B INTERFERON HEPATITIS B e ANTIGEN Treatment Model
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Chinese Hα Solar Explorer(CHASE)——a complementary space mission to the ASO-S 被引量:14
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作者 Chuan Li Cheng Fang +18 位作者 Zhen Li Ming-De Ding Peng-Fei Chen Zhe Chen Liang-Kui Lin Chang-Zheng Chen Chang-Ya Chen Hong-Jiang Tao Wei You Qi Hao yu dai Xin Cheng Yang Guo Jie Hong Min-Jie An Wei-Qiang Cheng Jian-Xin Chen Wei Wang Wei Zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2019年第11期110-114,共5页
The Chinese HαSolar Explorer(CHASE)is designed to test a newly developed satellite platform and conduct solar observations.The scientific payload of the satellite is an Hαimaging spectrograph(HIS),which can,for the ... The Chinese HαSolar Explorer(CHASE)is designed to test a newly developed satellite platform and conduct solar observations.The scientific payload of the satellite is an Hαimaging spectrograph(HIS),which can,for the first time,acquire full-disk spectroscopic solar observations in the Hαwaveband.This paper briefly introduces CHASE/HIS including its scientific objectives,technical parameters,scientific application system,etc.The CHASE mission is scheduled to launch in 2021.It will complement the observations by on-orbit solar spacecraft(such as SDO,IRIS,STEREO and PSP),as well as future solar missions of the Solar Orbiter and Advanced Space-based Solar Observatory(ASO-S). 展开更多
关键词 instrumentation spectrographs-Sun atmosphere-Sun activity
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Synthesis of Commercial-Scale Tungsten Carbide-Cobalt (WC/Co) Nanocomposite Using Aqueous Solutions of Tungsten (W), Cobalt (Co), and Carbon (C) Precursors 被引量:4
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作者 T. Danny Xiao Xinglong Tan +4 位作者 Maozhong Yi Shigao Peng Fangcai Peng Jiangao Yang yu dai 《Journal of Materials Science and Chemical Engineering》 2014年第7期1-15,共15页
This paper reports the chemical synthesis of tungsten carbide/cobalt (WC/Co) nanocomposite powders via a unique chemical processing technique, involving the using of all water soluble solution of W-, Co- and C-precurs... This paper reports the chemical synthesis of tungsten carbide/cobalt (WC/Co) nanocomposite powders via a unique chemical processing technique, involving the using of all water soluble solution of W-, Co- and C-precursors. In the actual synthesis, large quantities of commercial-scale WC-Co nanocomposite powders are made by an unique combination of converting a molecularly mixed W-, Co-, and C-containing solutions into a complex inorganic polymeric powder precursor, conversion of the inorganic polymeric precursor powder into a W-Co-C-O containing powder intermediates using a belt furnace with temperature at about 500°C - 600°C in an inert atmosphere, followed by carburization in a rotary furnace at temperature less than 1000°C in nitrogen. Liquid phase sintering technique is used to consolidate the WC/Co nanocomposite powder into sintered bulk parts. The sintered parts have excellent hardness in excess of 93 HRA, with WC grains in the order of 200 - 300 nm, while Co phase is uniformly distributed on the grain boundaries of the WC nanoparticles. We also report the presence of cobalt Co precipitates inside tungsten carbide WC nanograins in the composites of the consolidated bulk parts. EDS is used to identify the presence of these precipitates and micro-micro-diffraction technique is employed to determine the nature of these precipitates. 展开更多
关键词 TUNGSTEN Carbide/Cobalt NANOCOMPOSITE Chemical Synthesis Spray Conversion Belt FURNACE Rotary FURNACE Water Soluble Precursors COBALT NANOGRAIN Precipitates
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A new multi-wavelength solar telescope: Optical and Near-infrared Solar Eruption Tracer (ONSET) 被引量:9
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作者 Cheng Fang Peng-Fei Chen +8 位作者 Zhen Li Ming-De Ding yu dai Xiao-yu Zhang Wei-Jun Mao Jun-Ping Zhang Ting Li Yong-Jun Liang Hai-Tian Lu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2013年第12期1509-1517,共9页
A new multi-wavelength solar telescope, the Optical and Near-infrared Solar Eruption Tracer (ONSET) of Nanjing University, has been constructed. It was fabricated at the Nanjing Institute of Astronomical Optics & T... A new multi-wavelength solar telescope, the Optical and Near-infrared Solar Eruption Tracer (ONSET) of Nanjing University, has been constructed. It was fabricated at the Nanjing Institute of Astronomical Optics & Technology, and the oper- ation is jointly administered with Yunnan Astronomical Observatory. ONSET is able to observe the Sun in three wavelength windows: He I 10830 A, Ha and white-light at 3600 A and 4250 A, which are selected in order to simultaneously record the dynam- ics of the corona, chromosphere and photosphere respectively. Full-disk or partial-disk solar images with a field of 10~ at three wavelengths can be obtained nearly simultane- ously. It is designed to trace solar eruptions with high spatial and temporal resolutions. This telescope was installed at a new solar observing site near Fuxian Lake in Yunnan Province, southwest China. The site is located at E102N24, with an altitude of 1722 m. The seeing is stable and has high quality. We give a brief description of the scientific objectives and the basic structure of ONSET. Some preliminary results are also pre- sented. 展开更多
关键词 techniques: photometric -- Sun: observation -- Sun: telescope
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MapReduce Scheduler by Characterizing Performance Interference
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作者 Lei Yang yu dai Bin Zhang 《China Communications》 SCIE CSCD 2016年第10期253-262,共10页
Recently, virtualization has become more and more important in the cloud computing to support efficient flexible resource provisioning. However, performance interference among virtual machines(VMs) has become a challe... Recently, virtualization has become more and more important in the cloud computing to support efficient flexible resource provisioning. However, performance interference among virtual machines(VMs) has become a challenge which may affect the effectiveness of resource provisioning. In a virtual cluster which runs the Map Reduce applications, the performance interference can also affect the performance of the Map and Reduce tasks and thus cause a performance degradation of the Map Reduce job. Accordingly, this paper presents a Map Reduce scheduling framework to mitigate this performance degradation caused by the performance interference. The framework includes a performance interference prediction module and an interference aware scheduling algorithm. To verify its effectiveness, we have done a set of experiments on a 24-node virtual Map Reduce cluster. The experiments illustrate that the proposed framework can achieve a performance improvement in the virtualized environment compared with other Map Reduce schedulers. 展开更多
关键词 Map Reduce SCHEDULER performance interference
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The Origin and Acceleration of ~3He and Heavy Ions in the 2000 July 14 Event
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作者 Gui-Ping Wu Guang-Li Huang +1 位作者 yu-Hua Tang yu dai 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2007年第1期141-147,共7页
According to the evolutionary properties of the flare, halo coronal mass ejection (CME), enrichments of 3He ions in the energy range of 3.5-26 MeV nucl^-1 and Ne, Mg, Si and Fe ions in the energy range of 8.5-15 MeV... According to the evolutionary properties of the flare, halo coronal mass ejection (CME), enrichments of 3He ions in the energy range of 3.5-26 MeV nucl^-1 and Ne, Mg, Si and Fe ions in the energy range of 8.5-15 MeV nucl^- 1, we argue that the 3He and heavy ions originate in the middle corona (-0.1-1 R⊙) with well-connected open field lines to the Earth, where the magnetic reconnection leads to acceleration of the electrons and the production of type-ll burst during the decay phase of the soft X-ray emission. The acceleration of 3He and heavy ions may have been accomplished in two stages: first H-He ion-ion hybrid waves may be easily excited by the energetic electron beams produced in the middle corona, and these waves are preferentially absorbed by ZHe and heavy ions due to their frequency being near the fundamental gyro frequency of the ZHe ions and harmonic gyro frequency of Ne, Mg, Si and Fe ions. These preheated ions escape into interplanetary space along the open field lines and may be further accelerated to tens of MeV nucl^- 1 by CME-driven shock. The theoretical calculations show that the ZHe and heavy ions may be accelerated to the energy of - MeV nucl^-1 by the ion-ion hybrid waves and be further accelerated to the energy of -100 MeV nucl^-1 by the shock wave: these are basically consistent with the observations. 展开更多
关键词 SUN abundances-waves-shock wave-acceleration of particles
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