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Vascular bundle connection between seed stalk and seed coat of Caragana arborescens

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Journal of Forestry Research 2018年第1期29卷 253-257页

作者： Zhihui Luan Daowei Zhou Diankun Shao School of Life Sciences Changchun Normal University 677 North Changji Road Changchun 130032 Jilin Province People's Republic of China Northeast Institute of Geography and Agroecology Chinese Academy of Sciences 4888 Shengbei Street Changchun 130102 Jilin Province People's Republic of China Jilin Provincial Institute of Forest Inventory and Planning 3698 Yatai Street Changchun 130022 Jilin Province People's Republic of China

The purpose of this study was to investigate the morphology, transmission route of photosynthetic products in the seed stalk of Caragana arborescens Lam. at various stages after flowering and evaluate the role of the seed stalk in seed maturation using scanning electron microscopy. We found that the mature seed stalk mainly consisted of vessels,sclerenchymatous cells and parenchymatous cells. Elongated cells formed a ring at the junction between the seed stalk and seed, and a large hollow was produced by two layers of sclerenchymatous cells in the interior seed, which functions to sustain seed growth. The opening in the center of the ring was closed during an early stage of seed development, and the opening enlarged as the seed matured.There were two routes for material transport, which started from the seed stalk： one from the seed coat to the embryo,and another directly entering the embryo. Vessels, which are abundant in the seed stalk, are the pathway for absorption of nutrients by the seeds. The vessels were densely packed in the seed stalk, and secondary thickening of the cell wall of the vessels was characterized by net thread thickening, while the secondary thickening of the cell wall of the vessels within the seed was characterized by screw thread thickening. The morphological characteristics of the vessels were adaptive to its functions.

关键词： Caragana arborescens Seed coat Seed stalk Vascular bundle connection

Effects of fencing on vegetation and soil restoration in a degraded alkaline grassland in northeast China

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Journal of Arid Land 2014年第4期6卷 478-487页

作者： Qiang LI Daowei Zhou YingHua JIN MinLing WANG YanTao SONG GuangDi LI Northeast Institute of Geography and Agroecology Chinese Academy of Sciences University of Chinese Academy of Sciences School of Geography Science Northeast Normal University Graham Centre for Agricultural Innovation New South Wales Department of Primary Industries and Charles Sturt University

In order to restore a degraded alkaline grassland, the local government implemented a large restoration project using fences in Changling county, Jilin province, China, in 2000. Grazing was excluded from the protected area, whereas the grazed area was continuously grazed at 8.5 dry sheep equivalent（DSE）/hm2. In the current research, soil and plant samples were taken from grazed and fenced areas to examine changes in vegetation and soil properties in 2005, 2006 and 2008. Results showed that vegetation characteristics and soil properties improved significantly in the fenced area compared with the grazed area. In the protected area the vegetation cover, height and above- and belowground biomass increased significantly. Soil pH, electrical conductivity and bulk density decreased significantly, but soil organic carbon and total nitrogen concentration increased greatly in the protected area. By comparing the vegetation and soil characteristics with pre-degraded grassland, we found that vegetation can recover 6 years after fencing, and soil pH can be restored 8 years after fencing. However, the restoration of soil organic carbon, total nitrogen and total phosphorus concentrations needed 16, 30 and 19 years, respectively. It is recommended that the stocking rate should be reduced to 1/3 of the current carrying capacity, or that a grazing regime of 1-year of grazing followed by a 2-year rest is adopted to sustain the current status of vegetation and soil resources. However, if N fertilizer is applied, the rest period could be shortened, depending on the rate of application.

关键词： vegetation and soil restoration fencing grazing alkaline soil semi arid region grassland degradation

Effects of vegetation height and density on soil temperature variations

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Chinese Science Bulletin 2013年第8期58卷 907-912页

作者： SONG YanTao zhou daowei ZHANG HongXiang LI GuangDi JIN YingHua LI Qiang Institute of Grassland Science Northeast Normal University Key Laboratory of Vegetation Ecology Ministry of Education Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Graham Centre for Agricultural Innovation (alliance between Industry&Investment NSW and Charles Sturt University) Wagga Wagga Agricultural Institute

Reduction in vegetation cover caused by human activities has a great impact on soil temperature. It is important to assess how soil temperature responds to reduction of vegetation height and density. In this paper we first report the trends of mean annual soil surface and air temperatures recorded at the meteorological stations near the Ecological Research Station for Grassland Farming (ERSGF) from 1961 to 2007, then we setup an experiment using reed (Phragmites australis) stalks with different heights and densities to simulate effects of different vegetation height and density on soil and air temperatures. The warming rates of the mean annual soil and air temperatures were 0.043 and 0.041C a 1 , respectively. Changes of soil temperature were characterized by both increased mean annual maximum and minimum soil temperatures. At the experimental site, mean daily temperature, mean daily maximum soil and air temperatures increased significantly. In contrast, mean daily minimum soil temperature increased significantly while mean daily minimum air temperature decreased significantly as the height and density of reed stalks reduced during the experimental period. Mean diurnal soil temperature ranges were smaller than mean diurnal air temperature ranges. These results highlight that the importance of vegetation cover on soil and air temperatures.

关键词：土壤温度植被高度密度空气温度气温记录植被覆盖实验场地温度范围

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新型耐迁移橡胶防老剂的研究进展

化工进展 2023年第7期42卷 3708-3719页

作者：欧阳素芳周道伟黄伟贾凤中国石油化工股份有限公司科技部北京100728 中石化南京化工研究院有限公司江苏南京210048

首先介绍了橡胶防老剂的相关理论研究,橡胶材料老化的本质为自由基反应,其防护机理主要是抑制自由基的形成,实验研究集中于差示扫描量热、核磁、紫外分光、红外光谱等分析橡胶材料以及防老剂的结构变化,而理论研究则集中于分子模拟,包... 详细信息

首先介绍了橡胶防老剂的相关理论研究,橡胶材料老化的本质为自由基反应,其防护机理主要是抑制自由基的形成,实验研究集中于差示扫描量热、核磁、紫外分光、红外光谱等分析橡胶材料以及防老剂的结构变化,而理论研究则集中于分子模拟,包括解离能、溶解度、均方位移等参数计算。其次,通过对国内外商业化橡胶防老剂的使用现状进行追踪,分析了新型橡胶防老剂的开发与应用情况,包括胺类防老剂的改性方法、防老剂的复配研究以及具备特殊功能的新型防老剂应用等,结合几类耐迁移橡胶防老剂的结构特点和应用结果,指出具备耐迁移和低毒性等特点的新型橡胶防老剂是未来发展方向。最后,总结了新型耐迁移橡胶防老剂应集中于发挥防老剂大分子化和多官能化的协同作用,可以更好地适应橡胶工业的持续发展。

关键词：橡胶防老剂老化机理耐迁移分子模拟

白腐菌对玉米秸秆营养价值及抗氧化性能的影响

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动物营养学报 2017年第11期29卷 4108-4115页

作者：王雨琼周道玮中国科学院东北地理与农业生态研究所长春130102 中国科学院大学北京100049

本试验旨在研究白腐菌对玉米秸秆营养价值及抗氧化性能的影响。选取4种侧耳属白腐菌,分别为红侧耳(Pleurotus diamor)、金顶侧耳(Pleurotus citrinopileatus)、刺芹侧耳(Pleurotus eryngii)和漏斗状侧耳(Pleurotus sajor caju)。对照组... 详细信息

本试验旨在研究白腐菌对玉米秸秆营养价值及抗氧化性能的影响。选取4种侧耳属白腐菌,分别为红侧耳(Pleurotus diamor)、金顶侧耳(Pleurotus citrinopileatus)、刺芹侧耳(Pleurotus eryngii)和漏斗状侧耳(Pleurotus sajor caju)。对照组玉米秸秆不接种菌株,试验组玉米秸秆分别接种4种侧耳属白腐菌,每个组设置3个重复,固态发酵20 d,测定发酵物的营养成分含量和体外干物质消化率(IVDMD),并评估其抗氧化性能。结果显示:1)红侧耳组总有机物(TOM)损失率显著高于金顶侧耳组和刺芹侧耳组(P<0.05),漏斗状侧耳组酸性洗涤木质素(ADL)损失率显著高于其他各组(P<0.05),金顶侧耳组纤维素(CL)损失率显著高于刺芹侧耳组和漏斗状侧耳组(P<0.05),金顶侧耳组半纤维素(HC)损失率显著高于其他各组(P<0.05)。2)金顶侧耳组的粗蛋白质(CP)含量显著高于对照组(P<0.05),金顶侧耳组、漏斗状侧耳组和红侧耳组的粗脂肪(EE)含量显著高于对照组(P<0.05),4种白腐菌组的总氨基酸含量显著高于对照组(P<0.05),4种白腐菌组的IVDMD显著高于对照组(P<0.05)。3)4种白腐菌组的1,1-二苯基2-三硝基苯肼(DPPH)自由基清除力、还原力、总抗氧化能力和总酚含量均显著高于对照组(P<0.05)。由此可见,白腐菌预处理的玉米秸秆能提高其IVDMD、CP含量及抗氧化性能,可以作为反刍动物新型饲料资源。

关键词：白腐菌玉米秸秆抗氧化性能

Effect of Autumn Cutting Date on Regrowth, Turning Green, Yield and Quality of <i>Leymus chinensis</i>Grassland in Songnen Plain, Northeast China

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American Journal of Plant Sciences 2018年第2期9卷 185-195页

作者： Yantao Song &ensp Wuyunna Daowei Zhou College of Environment and Bioresources Dalian Minzu University Dalian China Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun China

A field study was carried out to quantify the effects of different cutting time on Leymus chinensis population and community characteristic in Songnen grassland of northeast China from August, 2006 to August, 2007. The treatment interval was ten days with the remaining stubble height of 5 cm from 15th August to 4th October in 2006. Results showed that the L. chinensis made up about 90% of the dry matter of aboveground biomass, and there were about ten species in the L. chinensis community in the 1 m × 1 m plot. The L. chinensis and Kalimeris integrifolia regrew rapidly after autumn cutting in 2016. In the second year, the coefficients of the community similarity were high between the different cutting time treatments. The density, height, aboveground biomass, stem/leaf ratio, and crude protein of L. chinensis were not significant at the turning green stage and harvesting stage, the companion species of L. chinensis community contained higher crude protein, but the crude protein of the plant community were not significant. Thus, considering the weather factor for haymaking, the harvest dates should be concentrated from the middle ten days of August to the first ten days in September.

关键词： Leymus chinensis Autumn Cutting Hay Yield Quality Songnen Grass-land

超声造影联合剪切波弹性成像评估乳腺癌病灶可切除性的研究

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影像科学与光化学 2022年第6期40卷 1375-1380页

作者：宫文亮周建朱道伟安徽医科大学附属滁州医院(滁州市第一人民医院)超声科安徽滁州239000

探讨超声造影(CEUS)联合剪切波弹性成像(SWE)评估乳腺癌病灶可切除性的价值。本文选取103例乳腺癌患者作为研究对象,根据临床实际分为手术切除组(61例)与不可手术切除组(42例),均行CEUS、SWE检查。结果发现:不可手术切除组达峰时间(TTP... 详细信息

探讨超声造影(CEUS)联合剪切波弹性成像(SWE)评估乳腺癌病灶可切除性的价值。本文选取103例乳腺癌患者作为研究对象,根据临床实际分为手术切除组(61例)与不可手术切除组(42例),均行CEUS、SWE检查。结果发现:不可手术切除组达峰时间(TTP)短于手术切除组。峰值强度(PI)、上升支斜率(WIS),以及杨氏模量值平均值(Emean)、最小值(Emin)、最大值(Emax)均高于手术切除组。TTP与Emean、Emin、Emax呈负相关,PI、WIS与Emean、Emin、Emax呈正相关(P<0.05)。TTP低水平患者不可手术切除的风险是高水平患者的2.084倍,PI、WIS、Emean、Emin、Emax高水平患者不可手术切除的风险分别是低水平患者的1.883倍、2.179倍、2.443倍、1.894倍、2.003倍。TTP、PI、WIS、Emean、Emin、Emax联合评估乳腺癌病灶可切除性的AUC为0.916,敏感度为85.71%,特异度为83.61%,优于各参数单独评估。提示CEUS联合SWE评估乳腺癌病灶可切除性的价值较为可靠,可为临床准确评估手术可行性提供参考依据。

关键词：乳腺癌可切除性超声造影剪切波弹性成像杨氏模量

Modulating contact properties by molecular layers in organic thin-film transistors

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Electron

Electron 2023年第2期1卷 82-89页

作者： Li Sun Yating Li Jiacheng Xie Liqi zhou Peng Wang Jian-Bin Xu Yi Shi Xinran Wang daowei He National Laboratory of Solid State Microstructures Key Lab of Optoelectronic Devices and Systems with Extreme PerformancesSchool of Electronic Science and Engineeringand Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjingChina National Laboratory of Solid State Microstructures Jiangsu Key Laboratory of Artificial Functional MaterialsCollege of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjingChina Department of Physics University of WarwickCoventryUK Department of Electronic Engineering and Materials Science and Technology Research Center The Chinese University of Hong KongHong Kong SARChina School of Integrated Circuits Nanjing UniversitySuzhouChina

Advanced organic devices and circuits demand both ultrahigh charge carrier mobilities and ultralow-resistance contacts.However,due to a larger access resistance in staggered organic thin-film transistors(OTFTs),the achievement of ultralow contact resistance(Rc)is still a challenge.The modulation of contact resistance by molecular layers near the interface has been rarely reported.Here,we demonstrate that fewlayer organic single crystals are grown on hafnium oxide(HfO_(2))by solution-shearing epitaxy.We utilize these organic crystals to fabricate bottom-gate staggered OTFTs with different contact processes.The results show that the contact properties of OTFTs are obviously modulated by crystal layers.The tri-layer(3L)evaporated-Au C10-DNTT OTFTs exhibit optimal electrical performance,including ultralow Rc of 5.6Ω⋅cm,recorded transfer length of 0.4μm,field-effect mobility over 14 cm^(2)V^(−1)s^(−1),threshold voltage lower than 0.3 V,and long-term air stability over 8 months.The main cause is that the metal atoms can penetrate into the charge transport layer,with damage-free,in 3L evaporated-Au OTFTs;nevertheless,it cannot be realized in other cases.Due to layer stacking of conjugated molecules and polymers,our strategy can efficiently modulate the contact resistance to aid the development of highperformance organic devices and circuits.

关键词： contact resistance mobility organic thin-film transistor single crystal

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农田氮肥残留效应及其影响因素

土壤与作物 2024年第2期13卷 201-214页

作者：马若男李强周道玮吉林省草地畜牧重点实验室/中国科学院东北地理与农业生态研究所吉林长春130102 中国科学院大学北京100049

氮肥利用效率的科学评估对指导农业生产至关重要。传统氮肥评估方案仅能反映当季肥料的利用效率,而忽视了氮肥的残留效应。本文综述了肥料氮的转运、氮肥残留数量、分布、利用及其影响因素,基于当前研究进展提出未来研究方向及相关研究... 详细信息

氮肥利用效率的科学评估对指导农业生产至关重要。传统氮肥评估方案仅能反映当季肥料的利用效率,而忽视了氮肥的残留效应。本文综述了肥料氮的转运、氮肥残留数量、分布、利用及其影响因素,基于当前研究进展提出未来研究方向及相关研究对农业管理实践的启示。农田输入的肥料氮,除了可以被当季作物吸收利用外,残留在土壤中的氮也可以继续被后续作物吸收利用,即评估肥效时,应该考虑氮肥的后效,而残留氮肥的回收利用受自身迁移和转化、作物种类、地力条件、气候环境、耕作管理等多个因素耦合影响。生产实践中,对决定残留氮肥回收效率的外部因素进行优化调控,诸如在长期浅根系/氮吸收低效作物种植后,轮作深根系/氮高效吸收型作物,合理密植,在干旱区适时灌溉保墒。针对作物氮肥喜好合理定制肥料类型,结合水肥一体化技术实施分次施肥,施氮同时配施微生物氮转化联合抑制剂均可有效提高氮肥总体利用率。利用15N同位素示踪技术,整合残留肥效和土壤氮素矿化等动态监测数据,配合作物类型、预期管理、目标产量等多要素数据,建立一套氮肥残留肥效的预测评估及氮肥减施的决策支持模型,对于指导未来的氮肥精准减施和提升农业生产效益具有重要科学意义。

关键词：农田氮肥利用效率氮肥残留残留氮肥回收施肥管理