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Plant type effect overweighs seasonal variation in n-alkanoic acid biomarker on regional Loess Plateau of China

Science China Earth Sciences 2024年第8期67卷 2547-2562页

作者： Jinzhao LIU S.Nemiah LADD jiaju zhao Dongna YAN Ding HE Yunning CAO Zhisheng AN State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China CAS Center for Excellence in Quaternary Science and Global Change Xi’an 710061China Department of Environmental Sciences University of BaselBasel 4056Switzerland Department of Ocean Science and Center for Ocean Research in Hong Kong and Macao The Hong Kong University of Science and TechnologyHong Kong 999077China

The effect of plant type on n-alkane biomarker has been widely studied,but the influence of plant type on n-alkanoic acids(n-FAs)has received less *** the effect of the distribution of n-FAs and their hydrogen isotope composition(δ^(2)H_(FA))is critical for interpreting sedimentaryδ^(2)H_(FA)values as proxies of hydroclimate and/or vegetation *** this study,we systematically investigated the distribution ofn-FAs andδ^(2)H_(FA)values across seasons on the Chinese Loess Plateau(CLP).Our results showed that there were no significant seasonal differences in n-FAs distribution andδ^(2)H_(FA)values,but there were significant differences inδ^(2)H_(FA)values across plant ***δ^(2)H_(FA)values ranged from-185‰to-125‰in dicots(-161‰±28‰),and from-215‰to-170‰in monocots(-196‰±22‰)on the *** fractionation betweenδ^(2)H_(FA)values and precipitationδ^(2)H(ε_(FA-P))was also^(2)H-enriched in dicots relative to *** the regional scale of the CLP,δ^(2)H_(FA)values were not correlated withδ^(2)H values of ***,δ^(2)H_(FA)values from the CLP were similar to expectations from a global comparison,both in terms of their mean values and high variability among plants growing in sites with similarδ^(2)H values of *** some of this variability inεFA-Pis due to the effect of plant type,a careful assessment of the likely sources of waxes in terrestrial sediments is critical when usingδ^(2)H_(FA)values for paleohydroclimate reconstruction.

关键词： n-Alkanoic acid Hydrogen isotope Plant type Paleohydroclimate Chinese Loess Plateau

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铁基纳米颗粒在磁共振成像中的研究进展

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医学综述 2024年第14期30卷 1749-1755页

作者：赵嘉驹胡黎文郭婷华南理工大学医学院广州510006 华南理工大学材料科学与工程学院广州510006

铁基纳米颗粒具有超顺磁性、低毒性、高磁化率等独特的物理、化学和高生物相容性的特点,是一类典型的磁共振成像(MRI)造影剂,包括磁性氧化铁纳米颗粒和超顺磁性氧化铁纳米颗粒两种。它能够与外加磁场产生局部磁矩,并引起局部磁场改变自... 详细信息

铁基纳米颗粒具有超顺磁性、低毒性、高磁化率等独特的物理、化学和高生物相容性的特点,是一类典型的磁共振成像(MRI)造影剂,包括磁性氧化铁纳米颗粒和超顺磁性氧化铁纳米颗粒两种。它能够与外加磁场产生局部磁矩,并引起局部磁场改变自旋方向,具有很好的对比度和信噪比,产生较高的MRI信号强度和对比度,能够提供清晰的图像。同时,铁基纳米颗粒具有较好的生物相容性和较低的细胞毒性,对人体安全性较高,特别是在MRI对肿瘤和炎症等疾病进行早期诊断和治疗时,在实现肿瘤协同精准治疗过程中发挥重要作用。随着铁基纳米颗粒合成技术的提高,医工多学科交叉融合可实现新型造影剂对靶点的精准定位和高分辨率成像,为疾病治疗和生物医学的发展做出巨大贡献。

关键词：磁共振成像铁基纳米颗粒磁性氧化铁

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新能源制氢系统及电源研究现状

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电工技术 2024年第S01期 453-456页

作者：李阳赵嘉驹史铁孔卫江余会明中船(邯郸)派瑞氢能科技有限公司河北邯郸056300 中国船舶集团有限公司第七一八研究所河北邯郸056300

整体介绍了风、光新能源制氢系统的组成,及电解槽电源的现状和研究方向。首先介绍了在风电场景中对整流电源的要求,此场合中主流的电源拓扑结构,之后分析多脉波整流器以及全控性IGBT整流器的性能特点。在光伏发电中,介绍主流光伏制氢系... 详细信息

整体介绍了风、光新能源制氢系统的组成,及电解槽电源的现状和研究方向。首先介绍了在风电场景中对整流电源的要求,此场合中主流的电源拓扑结构,之后分析多脉波整流器以及全控性IGBT整流器的性能特点。在光伏发电中,介绍主流光伏制氢系统,电源拓扑、系统特点。之后介绍风光发电制氢系统,通过构建不同的预测模型,预测下一周期的风光发电数据,从而调动电解槽的负荷,实时消耗发电功率,维持系统的安全稳定运行,还介绍了新能源制氢系统储能承担的作用,及合理计算系统成本和储能成本问题。

关键词：电解制氢整流新能源制氢离网电力电子变换器

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Pollen-inferred vegetation and environmental changes since 16.7 ka BP at Balikun Lake, Xinjiang

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Chinese Science Bulletin 2010年第22期55卷 2449-2457页

作者： TAO ShiChen AN ChenBang CHEN FaHu TANG LingYu WANG ZongLi LU YanBin LI ZhiFei ZHENG TongMing zhao jiaju MOR Key Laboratory of West China's Environmental System Lanzhou University Lanzhou 730000 China Nanjing Institute of Geology and Paleontology Chinese Academy of Sciences Nanjing 210008 China

A high-resolution fossil pollen record from the sedimentary cores of Balikun Lake, northwestern China, combined with modern surface pollen data, is used to reconstruct the history of vegetation and climatic change since 16.7 cal. ka BP. Fossil pollen assem-blages and lithology indicate that the study area was dominated by desert. The desert had extremely arid climate and lower effec-tive moisture during 16.7–7.9 cal. ka BP, especially from 16.7 to 8.9 cal. ka BP when the lake maybe dried up. During 8.9–7.9 cal. ka BP, the environment gradually recovered in this area. It was then followed by the optimum period from 7.9 to 4.3 cal. Ka BP, when the effective moisture obviously increased. It was characterized by the typical desert-steppe/steppe vegetation and was ac-companied with several patch-birch woodlands around the lake. After that, a short but extremely arid climatic event occurred during 4.3–3.8 cal. ka BP, and the vegetation quickly changed from desert-steppe/steppe to desert. It was a relatively optimum period from 3.8 to 0.53 cal. ka BP showing typical desert-steppe/meadow-steppe landscape. Since 0.53 cal. ka BP, the climate has shown signs of deteriorating again. Furthermore, regional comparison shows that the characteristics of climatic and environmental evolution in this area were clearly different from East Asia monsoonal area during the last 16.7 cal. ka BP. It was characterized by the arid climate during the late-glacial and early Holocene, and relatively wet during the mid-late Holocene.

关键词：环境变化巴里坤湖花粉记录 BP 植被中晚全新世新疆气候变化

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Impacts of Defoliation on Morphological Characteristics and Non-Structural Carbohydrates of Populus talassica × Populus euphratica Seedlings

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Phyton-International Journal of Experimental Botany 2024年第7期93卷 1689-1703页

作者： Mengxu Su Zhanjiang Han Zhen zhao Xiaofeng Wu jiaju Wu College of Life Science and Technology Tarim UniversityXinjiang Production and Construction Corps Key Laboratory of Protection and Utilization of Biological Resources in Tarim BasinAlar843300China Agricultural Science Research Institute of the First Division Xinjiang Production and Construction CorpsAlar843300China

Leaves are important‘source’organs that synthesize organic matter,providing carbon sources for plant ***,we used Populus talassica×Populus euphratica,the dominant species in ecological and timber forests,to simulate carbon limitation through artiﬁcial 25%,50%,and 75%defoliation treatments and explore the effects on root,stem,and leaf morphology,biomass accumulation,and carbon allocation *** the 60th d after treat-ment,under 25%defoliation treatment,the plant height,speciﬁc leaf weight,root surface area and volume,and concentrations of non-structural carbohydrates in stem and root were signiﬁcantly increased by 9.13%,20.00%,16.60%,31.95%,5.12%,and 9.34%,respectively,relative to the *** was no signiﬁcant change in the growth indicators under 50%defoliation treatment,but the concentrations of non-structural carbohydrates in the leaf and stem signiﬁcantly decreased,showing mostly a negative correlation between *** opposite was observed in the *** 75%defoliation treatment,the plant height,ground diameter,leaf number,single leaf area,root,stem,and total biomass were signiﬁcantly reduced by 14.15%,10.24%,14.86%,11.31%,11.56%,21.87%,and 16.82%,respectively,relative to the *** concentrations of non-structural carbohydrates in various organs were signiﬁcantly reduced,particularly in the consumption of the starch concentrations in the stem and *** results indicated that carbon allocation strategies can be adjusted to increase the con-centration of non-structural carbohydrates in root and meet plant growth needs under 25%and 50%***,75%defoliation signiﬁcantly limited the distribution of non-structural carbohydrates to roots and stems,reduced carbon storage,and thus inhibited plant ***-induced carbon limitation altered the carbon allocation pattern of ***×***,and the relationship between carbon reserves in roots and tree growth recovery after defoliation was *** study

关键词： Populus talassica×Populus euphratica defoliation carbon limitation carbon allocation non-structural carbohydrates

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Hypoxia activates the hypoxia-inducible factor-1α/vascular endothelial growth factor pathway in a prostatic stromal cell line:A mechanism for the pathogenesis of benign prostatic hyperplasia

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Current Urology 2024年第3期18卷 185-193页

作者： Tao Zhang Changlin Mao Yao Chang jiaju Lyu Delong zhao Sentai Ding Department of Urology Shandong Provincial Hospital Affiliated to Shandong First Medical UniversityJinanChina Department of Urology Mindong Hospital Affiliated to Fujian Medical UniversityFuanChina

Background The development of benign prostatic hyperplasia(BPH)is closely related to hypoxia in the prostatic stroma,and the hypoxia-inducible factor-1α/vascular endothelial growth factor(HIF-1α/VEGF)pathway has been shown to significantly activate in response to *** underlying mechanism for activation of this pathway in the pathogenesis of BPH remains *** and methods We constructed HIF-1αoverexpression and knockdown BPH stromal(WPMY-1)and epithelial(BPH-1)cell lines,which were cultured under different oxygen conditions(hypoxia,normoxia,and hypoxia+HIF-1αinhibitor).Quantitative real-time polymerase chain reaction(qPCR)and Western blotting were applied to detect the expression of the HIF-1α/VEGF *** proliferation and apoptosis were analyzed by Cell Counting Kit-8 and flow *** used the miRWalk 2.0 database and Western blotting to predict the potential miRNA that selectively targets the HIF-1α/VEGF pathway,and verified the prediction by qPCR and dual-luciferase *** In a BPH stromal cell line(WPMY-1),the expression of VEGF was in accordance with HIF-1αlevels,elevated in the overexpression cells and decreased in the knockdown ***-induced HIF-1αoverexpression,which could be reversed by a HIF-1α***,the HIF-1αinhibitor significantly depressed cellular proliferation and promoted apoptosis in hypoxic conditions,assessed by Cell Counting Kit-8 and flow ***,in the BPH epithelial cell line(BPH-1),the expression level of HIF-1αdid not influence the expression of ***,a potential miRNA,miR-17-5p,regulating the HIF-1α/VEGF pathway was predicted from the miRWalk 2.0 database and Western blotting,and verified by qPCR and dual-luciferase *** In hypoxia,activation of the HIF-1α/VEGF pathway plays a crucial role in regulating cell proliferation in a BPH stromal cell *** by miR-17-5p may be the potential mechanism for the activation of this *** of thi

关键词： Benign prostatic hyperplasia Hypoxia-inducible factor-1α Vascular endothelial growth factor Pathogenesis miR-17-5p

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Anthropogenic origin of a change in the fire-climate relationship in northern China after~2000 yr BP:Evidence from a 15,500-year black carbon record from Dali Lake

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Journal of Geographical Sciences 2022年第6期32卷 1136-1156页

作者： ZHANG Zhiping LIU Jianbao CHEN Shengqian ZHANG Shanjia JIA Xin ZHOU Aifeng zhao jiaju CHEN Jie SHEN Zhongwei CHEN Fahu Key Laboratory of Western China’s Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China Group of Alpine Paleoecology and Human Adaptation(ALPHA) State Key Laboratory of Tibetan Plateau Earth SystemResources and Environment(TPESRE)Institute of Tibetan Plateau ResearchCASBeijing 100101China CAS Center for Excellence in Tibetan Plateau Earth Sciences CASBeijing 100101China School of Geography Nanjing Normal UniversityNanjing 210023China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentCASXi’an 710061China

There are debates regarding whether a wet and warm climate or a dry and cold climate dominated Holocene fire activity in northern China on the millennial timescale,and when human activities overtook climate change as the dominant control on fire occurrence in the *** we present a high-resolution fire history for the past~15,500 years from a sediment core in Dali Lake,located in the foothills of the Greater Hinggan Mountains,one of the areas of highest fire risk in *** results demonstrate that fire activity was rare during the last deglaciation(~15,500–11,700 yr BP),gradually increased at the beginning of the Holocene,and reached its highest level during~9000–5000 yr BP,after which there was a decreasing ***,after~2000 yr BP this decreasing trend ended,and the most prominent feature is a peak in fire activity during the Medieval Warm Period(MWP).Overall,fire activity corresponded well to changes in the East Asian summer monsoon(EASM)precipitation on the millennial timescale during~15,500–2000 yr BP,but this relationship changed after~2000 yr *** propose that fire activity in northern China on the millennial timescale during~15,500–2000 yr BP was dominated by the biofuels reserve under the control of the EASM *** contrast,with the intensification of human activities after~2000 yr BP,human activity caused a~62%–73%increase in fire activity,which altered the fire-climate relationship that had previously prevailed in northern *** results indicate that a wet-warm climate(increased EASM intensity),rather than a dry-cold climate,was the dominant control on fire activity in northern China during 15,500–2000 yr BP on the millennial timescale,but that human activities played an important role in fire occurrence after~2000 yr BP.

关键词： fire activity East Asian summer monsoon biofuels reserve human activities northern China

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Observation of maximal intrinsic chirality empowered by dual quasi-bound states in the continuum in a planar metasurface

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Photonics Research 2024年第2期12卷 244-252页

作者： XIN QI jiaju WU FENG WU SONG zhao CHAO WU YUEYANG MIN MINA REN YUFEI WANG HAITAO JIANG YUNHUI LI ZHIWEI GUO YAPING YANG WANHUA ZHENG HONG CHEN YONG SUN MOE Key Laboratory of Advanced Micro-Structured Materials School of Physics Science and EngineeringTongji UniversityShanghai 200092China School of Optoelectronic Engineering Guangdong Polytechnic Normal UniversityGuangzhou 510665China l3 Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology School of Physics Science and EngineeringTongji UniversityShanghai 200092China Department of Electrical Engineering Tongji UniversityShanghai 201804China State Key Laboratory on Integrated Optoelectronics Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China

Metasurfaces with spin-selective transmission play an increasingly critical role in realizing optical chiral responses,especially for strong intrinsic chirality,which is limited to complex three-dimensional *** this paper,we propose a planar metasurface capable of generating maximal intrinsic chirality and achieving dual-band spinselective transmission utilizing dual quasi-bound states in the continuum(quasi-BICs)caused by the structural symmetry ***,the value of circular dichroism(CD)and the transmittance of two kinds of circular polarization states can be arbitrarily controlled by tuning the asymmetry *** CD approaching unity with the maximum transmittance up to 0.95 is experimentally achieved in the dual ***,assisted by chiral BICs,the application in polarization multiplexed near-field image display is also *** work provides a new avenue to flexibly control intrinsic chirality in planar structure and offers an alternative strategy to develop chiral sensing,multiband spin-selective transmission,and high-performance circularly polarized wave *** basic principle and design method of our experiments in the microwave regime can be extended to other bands,such as the terahertz and infrared wavelengths.

关键词： planar intrinsic quasi

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三通道全内距下关节镜排钉技术在SandersⅡ、Ⅲ型跟骨骨折治疗中的应用

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中华外科杂志 2022年第6期60卷 546-551页

作者：冯仕明赵家举马超徐炜徐州市中心医院骨科徐州221009 苏州大学附属第二医院骨科苏州215004

目的探讨三通道全内距下关节镜排钉技术治疗SandersⅡ、Ⅲ型跟骨骨折的临床效果。方法回顾性分析2017年3月至2019年3月于徐州市中心医院骨科采用三通道全内距下关节镜排钉技术治疗的33例(33足)SandersⅡ、Ⅲ型跟骨骨折的患者资料。其中... 详细信息

目的探讨三通道全内距下关节镜排钉技术治疗SandersⅡ、Ⅲ型跟骨骨折的临床效果。方法回顾性分析2017年3月至2019年3月于徐州市中心医院骨科采用三通道全内距下关节镜排钉技术治疗的33例(33足)SandersⅡ、Ⅲ型跟骨骨折的患者资料。其中男性19例,女性14例,年龄(32.6±11.3)岁(范围:20~55岁)。Sanders分型Ⅱ型12例,Ⅲ型21例。受伤至手术时间(101.2±32.1)h(范围:6~140 h)。术前患者疼痛视觉模拟评分(VAS)为(6.4±2.9)分(范围:4~8分);美国骨科足踝外科协会(AOFAS)踝与后足评分为(63.3±11.8)分(范围:50~75分);SF-36生活质量评分为(94.8±9.1)分(范围:70~105分)。所有患者均使用三通道全内距下关节镜联合排钉技术进行固定,记录患者术后切口愈合情况、骨折复位情况及骨折愈合情况,采用VAS、AOFAS踝与后足评分、SF-36生活质量评分评估患肢疼痛和功能。手术前后评分的比较采用重复测量方差分析。结果所有患者均顺利完成手术,手术时间为(69.7±10.4)min(范围:40~110 min),患者均未行植骨术。所有患者术后第1天跟骨影像学评估满意,术后切口均获得一期愈合,未出现皮肤感觉异常及腓骨肌损伤并发症。所有患者均获得24个月随访,术后跟骨影像学指标(跟骨长度、跟骨宽度、跟骨高度、Bohler角、Gissane角)较术前明显改善(P值均0.05),提示骨折复位无丢失(P值均>0.05)。术后VAS、AOFAS踝与后足评分及SF-36生活质量评分较术前明显改善(P值均<0.01)。末次随访时,患者后足力线及功能恢复满意,跟骨外观及外侧壁外形恢复满意,AOFAS踝与后足评分为优27例,良4例,中2例,优良率为94.0%。结论三通道全内距下关节镜排钉技术,复位精准,固定可靠,功能效果满意,并发症少,是治疗SandersⅡ、Ⅲ型跟骨骨折可供选择的有效方法。

关键词：跟骨骨折关节镜技术三通道排钉技术

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Nd:YAG脉冲倍频激光的相干特性

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上海交通大学学报 1980年第3期 68-75页

作者：赵家驹上海交通大学应用物理系

用迈克尔逊干涉仪及照相法研究了Q 开关Nd:YAG 倍频激光的相干特性。在该实验研究中,测量了相干度|γ(τ)|与程差及输入能量和输入阈值能量比值的函数关系,在输入能量和阈值输入能量比值为3.2时,测得相干长度是40mm,用一迈克尔逊干涉仪... 详细信息

用迈克尔逊干涉仪及照相法研究了Q 开关Nd:YAG 倍频激光的相干特性。在该实验研究中,测量了相干度|γ(τ)|与程差及输入能量和输入阈值能量比值的函数关系,在输入能量和阈值输入能量比值为3.2时,测得相干长度是40mm,用一迈克尔逊干涉仪,激光束旋转180°后再与自己干涉,从所成干涉条纹可以推断光束的空间相干性。本文对实验结果作了物理解释。

关键词：激光场 Nd 干涉条纹视见度二次谐波实验点 YAG 倍频相干度相干特性固体激光器选横模选模技术

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