Subjects: Geosciences >> Geography submitted time 2024-03-01 Cooperative journals: 《干旱区研究》
Abstract： Soil shear resistance in the Riparian zone directly affects riverbank stability. Furthermore, theinfluence of freezing and thawing on the structure and mechanical properties of alpine meadow soils is directlyrelated to the collapse frequency and lateral migration of the river bank in the source region of the Yellow River.To investigate the change rules and generation mechanisms of the root bearing soil mass, the shear strength indexin the meandering Riparian zone of the source region of the Yellow River under the effects of freezing andthawing were assessed. The subsequent impacts of different root contents on the soil mass shear strength indexwere also determined using an indoor freeze-thaw direct shear test with remolded soil. The experimental resultsshow that plant roots can significantly and increasingly enhance soil cohesion, which can range from 2.7% to77.9%. Variations in the internal friction angle with root content were not significant. The freeze- thaw cycleweakens soil cohesion, especially in the early stages. The maximum decrease in cohesion of 19.0% occurred withthree freeze- thaw cycles, after which the changes stabilized, while the internal friction angle showed a slightincreasing trend. The effects of the freeze-thaw action on the shear strength index of the rooted soil is smallerthan that of the plain soil. Under the same freeze- thaw frequency conditions, the decrease in cohesion of therooted samples was found to be smaller than that of the plain soil samples. The root systems of meadow plantscan block the changes in soil temperature, reduce the decrease in soil cohesion, and increase with the rootcontent. When the root content reaches 11%, its weakening effect on soil cohesion is 4.2%-27.7% less than thatof plain soil. The Riparian zone, as the source area of the Yellow River, should strengthen the protection ofriverside meadow vegetation, maximize the role of the root system in enhancing Riparian stability, and protectriver ecology.
Subjects: Biology >> Ecology submitted time 2022-03-28 Cooperative journals: 《干旱区研究》
Abstract：为分析黄河源区高寒草甸植物单根的抗拉力学性质及其护岸的微观力学机理，以华扁穗草、线叶嵩草和金露梅3种优势滨河植物为研究对象，通过开展单根拉伸试验和石蜡切片试验，定量分析3种植物单根力学特性及其与微观结构的关系。结果表明，当根径在、0.5~1.0 mm和>1.0 mm 3个根径级别时，3种植物单根抗拉力和延伸率均随根径增大而增大；单根抗拉强度和杨氏模量均随根径增大而减小；根系应力-应变曲线表现为单峰曲线。灌木金露梅单根平均抗拉强度是草本植物华扁穗草和线叶嵩草的1.56倍和1.25倍，华扁穗草单根平均延伸率是线叶嵩草和金露梅的1.06倍和1.36倍。草本植物单根抗拉强度主要与其维管柱面积占比有关；而灌木金露梅单根抗拉强度主要与其周皮和次生木质部面积占比有关。综合来看，华扁穗草和线叶嵩草根系抵抗变形的能力较强，主要发挥加筋和减缓河岸变形、破坏的作用；而金露梅刚度强、抗拉强度较大，主要发挥固土护岸的作用。研究结果可为筛选黄河源区优势护岸植物提供科学依据。
Subjects: Psychology >> Management Psychology submitted time 2021-06-12
Abstract： [Objective] With organizations’ fast-paced development, employees' passion for work and their innovative behavior in the workplace inevitably faces the influences of time pressure as well as the life-history strategy of the organization’s development. According to the two-dimensional view of pressure, time pressure can be categorized into the challenge time pressure and the hindrance time pressure. According to the view of organizational duality, innovative behavior can be categorized into exploratory innovation and exploitative innovation. At the same time, the life-history strategy in the field of behavioral ecology can be introduced into organizational development to describe the pace and focus of an organization’s developmental strategy, and thus the life-history strategy of organizational development can be divided into the K strategy and the r strategy. [Methods] Through three survey experiments (Study 1, Study 2 and Study 3) and a questionnaire survey (Study 4), this paper explores the impact of different types of time pressure and organizational life-history strategies on employees' innovative behavior, and the role of employees' work passion in it. [Results] Study 1a (n = 75) and Study 1b (n = 74) found that the K strategy had a promoting effect on the participants’ exploratory innovation and harmonious work passion, and the r strategy had a promoting effect on the participants’ exploitative innovation and compulsory work passion. Study 2 (n = 282) found that compared with the hindrance time pressure, the challenge time pressure significantly promoted harmonious work passion and exploratory innovation while significantly inhibited compulsory work passion and exploitative innovation. Study 3 (n = 206) further verified the results of Study 1 and Study 2, and found the influences of four combinations of time pressure and organizational life-history strategy on work passion and innovation. Study 4 (n = 400) not only supported the findings of Study 3, but also further revealed the mediating roles that harmonious work passion and compulsive work passion played on the relationship between the combination of time pressure and organizational life-history strategy and the two types of innovative behavior. [Implications] The results suggest that: 1. The organizational life-history strategy has a direct impact on employees’ innovative behavior, with the K strategy promoting exploratory innovation and the r strategy promoting exploitative innovation, but these effects are not mediated by work passion; 2. The type of time pressure has a direct impact on employees’ work passion and an indirect impact on innovative behavior, with the challenge time pressure promoting exploratory innovation via elevating harmonious work passion and the hindrance time pressure promoting exploitative innovation via elevating compulsory work passion; 3. The impact of different combinations of time pressure and organizational development life history strategies on employees can be summarized into four types: the harmonious exploration type, the harmonious exploitation type, the positive contradiction type and the negative contradiction type. From the dual perspectives of the meso-level organizational life-history strategy and the micro-level time pressure, this study indicates the differential impacts and mechanisms of different combinations of organizational life-history strategy and time pressure on employees’ work passion and innovative behavior, which provides useful insights for the daily management practice of innovative organizations."
Peer Review Status:
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Subjects: Biology >> Botany >> Applied botany submitted time 2020-08-03 Cooperative journals: 《广西植物》
Abstract：为筛选冬青属植物优良防火品种，了解该属植物叶片燃烧表现特征，优化园林树种防火性能评价方法，该文以克恩氏冬青（Ilex × koehneana）、史蒂芬冬青（Ilex ‘Nellie R. Stevens’）、大别山冬青（Ilex dabieshanensis）、博福德冬青（Ilex cornuta ‘Burfordii’）、双核冬青（Ilexdipyrena）为研究对象，以海桐（Pittosporum tobira）和石楠（Photinia serrulata）作为参照，采用因子分析法对这 7 种植物鲜叶和干叶的防火性能分别进行综合评价。结果表明：（1）不同冬青品种鲜叶火灾性能指数存在显著性差异，其余指标均呈极显著性差异。（2）经过因子分析进行评价分析得出：鲜叶抗火性从强到弱依次为博福德冬青＞史蒂芬冬青＞大别山冬青＞石楠＞海桐＞双核冬青＞克恩氏冬青；干叶抗火性从强到弱依次为史蒂芬冬青＞大别山冬青＞博福德冬青＞海桐＞双核冬青＞克恩氏冬青＞石楠。（3）综合鲜叶及干叶的评分结果，得出博福德冬青、史蒂芬冬青、大别山冬青得分较高，防火性能优于石楠和海桐，防火性能表现更突出。
Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究葡萄原花青素（grape procyanidins,GPC）对产蛋后期蛋鸡生产性能、蛋品质及血浆、肝脏和蛋黄抗氧化能力的影响。选取产蛋率、体重相近，健康状态良好的64周龄罗曼蛋鸡288只，随机分为4组，每组6个重复，每个重复12只鸡。对照组：饲喂基础饲粮；GPC50组和GPC100组：分别在基础饲粮中添加50和100 mg/kg的GPC；抗氧化剂特丁基对苯二酚（tert-butyl hydroquinone,TBHQ）组：基础饲粮+200 mg/kg TBHQ。预试期7 d，正试期56 d。结果表明：1）GPC显著抑制了产蛋后期蛋鸡产蛋率和鸡蛋哈夫单位下降（P<0.05），显著增加了蛋壳厚度（P<0.05）。2）GPC50组蛋鸡血浆和肝脏总超氧化物歧化酶（T-SOD）活性和总抗氧化能力（T-AOC）均显著提高（P<0.05），血浆和肝脏丙二醛（MDA）含量显著降低（P<0.05）；TBHQ显著提高了蛋鸡血浆T-SOD活性（P<0.05），显著降低了肝脏MDA含量（P<0.05）。3）GPC显著提高了蛋黄T-SOD活性（P<0.05），显著降低了蛋黄MDA和胆固醇含量（P<0.05）；TBHQ显著降低了蛋黄MDA含量（P<0.05）。综上，饲粮添加GPC可改善产蛋后期蛋鸡产蛋率和哈夫单位，增加蛋壳厚度，改善机体抗氧化能力，其中以50 mg/kg GPC添加效果较好，优于200 mg/kg TBHQ。
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