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Relationship between multi-scale climate factors and performance of ecological engineering on the Loess Plateau, China

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Journal of Forestry Research 2022年第3期33卷 789-800页

作者： Panxing He Jun Ma Zhiming Han Mingjie Shi dongxiang xu Zongjiu Sun Ministry of Education Key Laboratory for Biodiversity Science and Ecological EngineeringNational Observations and Research Station for Wetland Ecosystems of the Yangtze EstuarySchool of Life SciencesFudan UniversityShanghai200438People’s Republic of China Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology College of Grassland and Environment SciencesXinjiang Agricultural UniversityUrumqi830052People’s Republic of China State Key Laboratory Base of Eco-Hydraulic Engineering in Arid Areas Xi’an University of TechnologyXi’an710077People’s Republic of China School of Earth and Environmental Sciences University of QueenslandSt Lucia4072Australia

The long-term “Grain-to-Green Program” (GGP) on China’s Loess Plateau is a major global ecological engineering project which has significantly boosted vegetation renewal. Some studies have found that the rate of restoration is quite rapid during the implementation of ecological engineering, however, the influence of multi-scale climatic conditions on the performance of ecological engineering is unclear. In this study, multiple sources of remote sensing data were used to estimate the dynamics of vegetation structural and functional indicators, water-related local climatic factors, and atmospheric circulation factors. These datasets were also used to detect possible causes for vegetation restoration on the Loess Plateau over the past 20 years. The results show that widespread increases in rates of normalized difference vegetation indexes (NDVI), leaf area indexes (LAI), gross primary production (GPP), and aboveground biomass carbon (ABC) during 2000–2016 were significantly higher than before 2000. GPP was significantly correlated with rainfall and surface runoff on a monthly scale, and there were significant positive correlations between GPP and atmospheric circulation. Our results demonstrate that both vegetation structural and functional indicators rapidly increase, and ecological engineering greatly accelerated vegetation restoration after 2000. Local climatic conditions and atmospheric circulation patterns enhance vegetation growth and impact of ecological engineering.

关键词： Vegetation restoration Ecological engineering Water-related climatic factors Atmospheric circulation and sunspot Loess Plateau

Combining gradual and abrupt analysis to detect variation of vegetation greenness on the loess areas of China

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Frontiers of Earth Science 2022年第2期16卷 368-380页

作者： Panxing HE Zongjiu SUN dongxiang xu Huixia LIU Rui YAO Jun MA Ministry of Education Key Laboratory for Western Arid Region Grassland Resources and Ecology College of Grassland and Environment SciencesXinjiang Agricultural UniversityUrumqi 830000China Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering Institute of Biodiversity ScienceFudan UniversityShanghai 200438China School of Earth and Environmental Sciences University of QueenslandQueensland 4072Australia Hubei Key Laboratory of Critical Zone Evolution School of Geography and Information EngineeringChina University of GeosciencesWuhan 430074China

The annual peak growth and trend shift of vegetation are critical in characterizing the carbon sequestration capacity of *** the well-known area with the fastest vegetation growth in the world,the Loess Plateau(LP)lands find an enhanced greening trend in the annual and ***,the spatiotemporal dynamics of vegetation peak growth and breakpoints characteristics on time series still needs to be ***,we performed tendency analysis to characterize recent variations in annual peak vegetation growth through a satellite-derived vegetation index(NDVI_(max),Maximum Normalized Difference Vegetation Index)and then applied breakpoint analysis to capture abrupt points on the time *** results demonstrated that the vegetation peak trend had been significantly increasing,with a growth rate at 0.68×10^(-2)·a^(-1) during 2001-2018,and most pixels(70.81%)have a positive linear greening trend over the entire *** addition,about 83%of the breakpoint type on the monthly NDVI time series is a monotonic increase at the pixel level,and most pixels(57%)have detected breakpoints after *** results also showed that the growth rate accelerates in the northwest and decelerates in the southeast after the *** study indicates that combining abrupt analysis with gradual analysis can describe vegetation dynamics more effectively and *** findings highlighted the importance of breakpoint analysis for monitor timing and shift using time series satellite data at a regional scale,which may help stakeholders to make reasonable and effective ecosystem management policies.

关键词： vegetation greenness gradual trend breakpoint BFAST algorithm the Loess Plateau area

Effect of age on aortic atherosclerosis

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Journal of Geriatric Cardiology 2013年第2期10卷 135-140页

作者： Michael A. Chen Miwa Kawakubo Patrick M. Colletti dongxiang xu Laurie LaBree Dustin Robert Detrano Stanley P Azen Nathan D. Wong xue-Qiao Zhao Department of Medicine Division of Cardiology Harborview Medical Center/University of Washington 325 9th Avenue Box 359748 Seattle WA 98104 USA Department of Preventive Medicine Division of Biostatistics Keck School of Medicine of the University of Southern California 2001 N Soto Street SSB 201A M/C 9234 Los Angeles CA 90089-9237 USA Department of Radiology Keck School of Medicine of the University of Southern California1 1500 San Pablo Street Second Floor Imaging Los Angeles CA 90033 USA Department of Radiology University of Washington School of Medicine Box 357115 1959 Pacific Street RR-215 Seattle WA 98195-7117 USA Department of Radiological Sciences University of California Irvine School of Medicine 101 the City Drive South Route 140 Orange CA 92868 USA Department of Medicine UC Irvine School of Medicine 333 City Blvd. West Suite 400 Orange CA 92868-3298 USA

Objective To examine the association of atherosclerosis burden in the survivors of an asymptomatic elderly cohort study and its relationship to other coronary risk factors (specifically, age) by evaluating aortic atherosclerotic wall burden by magnetic resonance imaging (MRI). Methods A total of 312 participants in an ongoing observational cohort study underwent cardiac and descending thoracic aorta imaging by MRI. Maximum wall thickness was measured and the mean wall thickness ***/outer wall ratio was used as a normalized wall index (NWI) adjusted for artery size difference among participants. Percent wall volume (PWV) was calculated as NWI ×*** In this asymptomatic cohort (mean age: 76 years), the mean (SD) aortic wall area andwall thicknesswere 222 ±45 mm2 and 2.7 ±0.4 mm, respectively. Maximum wall thickness was 3.4 ±0.6 mm, and PWV was 32% ±4%. Women appeared to have smaller wall area,but after correcting for their smaller artery size, had significantly higher PWV than men (P = 0.03). Older age was associatedwith larger wall area (P = 0.04 for trend) with similar PWVs. However, there were no statistically significant associations between standard risk factors,Framingham global risk, or metabolic syndrome status, therapy for cholesterol or hypertension, coronary or aortic calcium score, and the aortic wall burden. Aortic calcificationwas associated with coronary calcification. Conclusions Asymptomatic elderly in this cohort had a greater descending thoracic aortic wall volume that correlated with age, andwomen had a significantly increased PWV compared to men. In these survivors, the atherosclerotic aortic wall burden was not significantly associated with traditional risk factors or with coronary or aortic calcium scores or coronary calcium progression. Results suggest that age, or as yet unidentified risk factor(s), may be responsible for the increase in atherosclerosis.

关键词： Aging Aortic atherosclerosis Atherosclerotic risk factors Magnetic resonance imaging

Enhanced charge separation by incomplete calcination modified co-doped TiO_(2)nanoparticle for isothiazolinone photocatalytic degradation

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Nano Research 2024年第6期17卷 4834-4843页

作者： Zhiren Guo Xiao Zhang Xinyuan Li Chang Cui Zilei Zhang Hansheng Li dongxiang Zhang Jinying Li Xiyan xu Jiatao Zhang School of Chemistry and Chemical Engineering Beijing Institute of TechnologyBeijing 102488China Department of Chemistry MSU-BIT UniversityShenzhen 517182Chin

Photocatalytic oxidation techniques are promising for degradation of the highly ecotoxic and refractory isothiazolinone bactericides in relevant industrial ***,low charge separation and directional transport efficiency under solar light radiation restrain their practical ***,we report a nanostructured photocatalyst doped with Gd and B in TiO_(2)with carbon incorporation and defect formation through incomplete *** specific surface area,grain size,and hydrophilicity of TiO_(2)are improved,which is beneficial for the interfacial reaction between the photocatalyst and *** reduction of the bandgap,the broadening of the photo-absorption range,and the retarded electron-hole recombination promote the photocatalytic performance due to the improved oxygen vacancies based on the electron distribution *** difference in partial density of states(ΔPDOS)between the current catalyst and raw TiO_(2)indicates that the co-doping of Gd and B with incomplete calcination changes the electronic hybridization of conduction band and valence band near the Fermi level,and affects the band gap *** improved charge separation and directional transport efficiency and benefited the formation of main active species,including•OH and O_(2)•−,for the pollutant *** rate of photocatalytic removal of benzisothiazolinone(BIT)by the current photocatalyst reaches 1.25 h^(−1),being 4.31 times that of TiO_(2).The current work offers a constructive approach to the design and synthesis of nanostructured photocatalysts for the photocatalytic degradation of refractory organic pollutants.

关键词： TiO_(2)nanoparticle charge separation oxygen vacancies electron distribution modification photocatalytic degradation

维普期刊数据库评论

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舰载激光武器毁伤能力的建模与仿真

系统仿真技术 2021年第2期17卷 94-97页

作者：徐东翔解放军91404部队河北秦皇岛066001

随着舰载激光武器的不断发展,利用激光武器防御反舰导弹成为了一种重要手段。现有的激光武器毁伤效果模型较为简单,与实际应用存在一定差距。通过分析激光在大气中的传输特性,结合实际应用中存在的跟踪误差,建立了一种激光武器功率密度... 详细信息

随着舰载激光武器的不断发展,利用激光武器防御反舰导弹成为了一种重要手段。现有的激光武器毁伤效果模型较为简单,与实际应用存在一定差距。通过分析激光在大气中的传输特性,结合实际应用中存在的跟踪误差,建立了一种激光武器功率密度模型。通过仿真,分析了跟踪误差对功率密度的影响,为今后制定激光武器使用策略提供参考依据。

关键词：激光武器功率密度跟踪误差

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VBA在自动化软件中的应用

石油化工自动化 2006年第3期 64-65+73页

作者：徐冬翔中国科技大学安徽合肥230027

阐述了当前自动化软件的技术特点和发展趋势,并介绍了在iFIX自动化软件中使用VBA访问历史和实时数据的机制。通过一段使用VBA语言编写的程序,实现向Excel输出历史数据,生成历史报表的实例,说明了VBA语言在自动化软件中的应用。

关键词：实时数据历史数据自动化软件

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基于挂片法的铝溶胶腐蚀性能研究

石油炼制与化工 2023年第12期54卷 114-118页

作者：秦鹏飞周含徐冬翔孙敏刘新中石化石油化工科学研究院有限公司北京100083

在催化裂化、甲醇制烯烃等催化剂的制备过程中,作为黏结剂的铝溶胶溶液会对设备造成腐蚀,因此有必要对铝溶胶的性能及其对工业装置的腐蚀速率进行测定。而目前市售的腐蚀性能评价仪存在转速失真、温度延迟不准确、空泡效应等问题,从而... 详细信息

在催化裂化、甲醇制烯烃等催化剂的制备过程中,作为黏结剂的铝溶胶溶液会对设备造成腐蚀,因此有必要对铝溶胶的性能及其对工业装置的腐蚀速率进行测定。而目前市售的腐蚀性能评价仪存在转速失真、温度延迟不准确、空泡效应等问题,从而影响试验数据的准确性。本研究基于挂片法开发了一套新型四通道高效铝溶胶腐蚀性能评价仪,该仪器采用泵循环铝溶胶液体与原位加热控温相结合的方式,确保了测试体系内无显著温度梯度,优选了铝溶胶对20号碳钢挂片的腐蚀强化条件,最大相对误差仅2.3%,数据重复性良好。采用计算流体力学数值模拟方法研究了铝溶胶速度梯度对挂片腐蚀速率的影响,建立了预测腐蚀速率的计算式,为工业装置腐蚀防护提供了试验数据与模型支持。

关键词：铝溶胶腐蚀性能评价计算流体力学数值模拟

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卷绕系统反演滑模恒张力控制

电子测量技术 2023年第24期46卷 93-102页

作者：庞浩杜钦君赵金阳徐执诏徐东祥山东理工大学电气与电子工程学院淄博255022 淄博市产品质量检验研究院淄博255022

针对卷绕系统工作时卷料张力波动较大问题,提出了一种基于神经网络区间观测器的反演非奇异快速终端滑模张力控制方法。构建卷绕系统数学模型,利用神经网络逼近卷绕系统中卷料半径、惯量等参数变化部分所引起的随机响应,设计区间状态观... 详细信息

针对卷绕系统工作时卷料张力波动较大问题,提出了一种基于神经网络区间观测器的反演非奇异快速终端滑模张力控制方法。构建卷绕系统数学模型,利用神经网络逼近卷绕系统中卷料半径、惯量等参数变化部分所引起的随机响应,设计区间状态观测器估计系统转速、卷料张力的上下界。根据估计出的状态值,构建反演非奇异终端滑模控制器,使张力跟踪误差在有限时间内快速收敛到零,有效增强了系统鲁棒性能。仿真实验结果表明,所设计的控制方法使卷料上的张力在1.6 s后达到给定值并保持恒定,相较于常规的滑模控制器和已发表文献中的滑模控制器,其调节时间分别减少了57%和33%,证明了所提出控制方法的有效性和可靠性,满足卷绕设备收卷工艺的要求。

关键词：卷绕系统张力恒定控制反演控制终端滑模控制器区间观测器

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文冠果落果与内源脱落酸的关系

华北农学报 1986年第4期 90-95页

作者：杜盛徐贵锋徐东翔内蒙古林学院内蒙古林学院山东农业大学攻读硕士学位本院66届毕业生

文冠果在幼果期和果实膨大期出现两次落果高潮,脱落果实大约分别为雌花的75%和15%.本文用气相色谱法定量测定了两次落果期间不同状态果实的内源脱落酸(ABA)含量.结果表明:幼果期,脱落幼果脱落酸含量为不脱落幼果的2—9倍;果实膨大期停... 详细信息

文冠果在幼果期和果实膨大期出现两次落果高潮,脱落果实大约分别为雌花的75%和15%.本文用气相色谱法定量测定了两次落果期间不同状态果实的内源脱落酸(ABA)含量.结果表明:幼果期,脱落幼果脱落酸含量为不脱落幼果的2—9倍;果实膨大期停止生长的果实脱落酸含量为正常生长果实的1.1—1.8倍.可见,果实中高的内源脱落酸含量是引起文冠果脱果的重要因素之一.

关键词：文冠果落果内源脱落酸