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基于化学计量学分析生物炭-N配施的联合效应
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作者 王立 鞠畅 +1 位作者 陈荣健 油勇强 《哈尔滨工业大学学报》 EI CAS CSCD 北大核心 2023年第2期19-26,共8页
为探讨新型土壤调理剂——生物炭及氮肥配施对土壤养分调理的影响,采用培养实验结合化学计量方法分析玉米秸秆生物炭(SBC)、鸡粪生物炭(MBC)和氮肥(尿素)配施的添加效应。结果表明:生物炭能够提高土壤养分质量分数,但其调理效果具有剂... 为探讨新型土壤调理剂——生物炭及氮肥配施对土壤养分调理的影响,采用培养实验结合化学计量方法分析玉米秸秆生物炭(SBC)、鸡粪生物炭(MBC)和氮肥(尿素)配施的添加效应。结果表明:生物炭能够提高土壤养分质量分数,但其调理效果具有剂量依赖性和种类异质性。随着生物炭用量的提高,土壤养分质量分数呈上升趋势。SBC处理使土壤有机碳(SOC)和全磷(TP)质量分数最高提升101.754%和34.592%。MBC处理使土壤SOC和TP质量分数最高提升了23.684%和84.396%。SBC通过诱导土壤SOC质量分数的提高进而提高土壤碳氮质量比(C/N)和碳磷质量比(C/P)。而MBC处理则通过磷剂量稀释效应降低了土壤C/P和氮磷质量比(N/P)。生物炭和氮肥之间不是单一的叠加效应,实际应用过程中应充分考虑氮肥与生物炭的交互效应。 展开更多
关键词 生物炭 土壤调理剂 土壤养分平衡 化学计量 剂量依赖性 种类异质性
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大学生创业制约性情感因素分析 被引量:8
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作者 刘小戈 林济森 《北华大学学报(社会科学版)》 2006年第3期17-19,共3页
大学生在创业过程中面对困难和失败在所难免。能够勇于面对失败并坦然接受失败,是一种勇气,也是一种良好的情感品质。不惧挫折和摆脱依赖,是成功者在创业时期情感方面应该具备的个人心理素质。大学生创业者尤其需要这一良好情感因素的... 大学生在创业过程中面对困难和失败在所难免。能够勇于面对失败并坦然接受失败,是一种勇气,也是一种良好的情感品质。不惧挫折和摆脱依赖,是成功者在创业时期情感方面应该具备的个人心理素质。大学生创业者尤其需要这一良好情感因素的支持。 展开更多
关键词 大学生 创业 情感因素 依赖心理 制约性
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库存量影响需求的反向条件延期付款订货策略 被引量:1
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作者 贾涛 刘玉伟 +1 位作者 徐渝 贾娟 《运筹与管理》 CSSCI CSCD 北大核心 2016年第4期157-167,共11页
以现实中实物商品供应链的商业信用额度限制为背景,给出了一种新的条件延期还款策略。假设需求率从到货开始线性依赖于即时库存量,直到库存水平到达一个确定的值Qs后,需求率变为常数。为防止零售商大量订货造成供应商资金的过度占用,供... 以现实中实物商品供应链的商业信用额度限制为背景,给出了一种新的条件延期还款策略。假设需求率从到货开始线性依赖于即时库存量,直到库存水平到达一个确定的值Qs后,需求率变为常数。为防止零售商大量订货造成供应商资金的过度占用,供应商采用反向条件延期付款策略,即零售商在订货量小于等于某个确定值Q1时,可以延迟支付货款;反之,则必须立即支付所有货款。通过分析给出了该问题所有可能的决策区间,整理出零售商利润函数的四种不同形式,结合数学证明得到了每个目标函数的解析性质并给出了相应的命题,由此设计了求解步骤以有效地确定零售商的最优决策。数值算例表明在这种决策情境下零售企业完全可能主动放弃延时还款而增加订货量以获得更大的利润,由此得到一些有价值的管理启示。 展开更多
关键词 运筹学 库存管理 最优化 反向条件延期付款 需求率依赖于库存量
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城市客车非独立式空调系统设计 被引量:4
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作者 曾壮 《客车技术与研究》 2005年第3期26-29,共4页
目前,越来越多的城市客车选用非独立式空调系统。本文通过各种客车空调系统的布置特点分析,对城市客车空调系统的选型进行探讨,并从汽车空调的原理出发,对城市客车非独立式空调系统的设计作详细介绍。
关键词 城市客车 非独立式空调 设计选型
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随机环境影响下系统可靠性比较
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作者 丁艳红 张奕 《应用数学》 CSCD 北大核心 2016年第4期846-854,共9页
本文研究随机环境影响系统相依结构的情形下,系统可靠性的随机比较,文章采用连接函数表示系统的相依结构,研究不同随机环境因子下两个系统的象限序、弱多元失效率序、n中取k系统的寿命等的随机比较,并通过实际例子进行分析.
关键词 随机环境 相依结构 连接函数 随机序 n中取k系统 可靠性
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低地板客车非独立空调系统的几种电源形式
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作者 潘永昌 周广波 《客车技术与研究》 2002年第4期15-16,共2页
介绍低地板客车非独立空调系统几种电源形式的结构和使用特点
关键词 非独立空调系统 低地板客车 电源形式 结构 使用特点
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轨道车辆变频空调可维修性设计及展望 被引量:1
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作者 董娜 卢明书 +1 位作者 张显辉 郝春银 《铁道技术监督》 2018年第11期44-46,53,共4页
为了保障轨道车辆变频空调的可靠运行,同时防止空调过度维修、降低空调全寿命周期内的维护成本,对轨道车辆变频空调实施可维修性设计。首先介绍设计和运营过程中的可维修性指标,然后从产品设计和运营2个阶段入手阐述可维修性设计在轨道... 为了保障轨道车辆变频空调的可靠运行,同时防止空调过度维修、降低空调全寿命周期内的维护成本,对轨道车辆变频空调实施可维修性设计。首先介绍设计和运营过程中的可维修性指标,然后从产品设计和运营2个阶段入手阐述可维修性设计在轨道车辆变频空调中的应用。通过阐述可维修性的发展历程,指出以可靠性为中心的维修(RCM)和可信性维修(DCM)越来越占据轨道车辆变频空调可维修性设计的主导地位。 展开更多
关键词 轨道车辆 变频空调 可维修性 视情维修 可靠性 可信性维修
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Rice tissue-specific promoters and conditiondependent promoters for effective translational application 被引量:6
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作者 Hee-Jeong Jeong Ki-Hong Jung 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2015年第11期913-924,共12页
Rice (Oryza sativa) is one of the most important staple food crops for more than half of the world's population. The demand is increasing for food security because of population growth and environmental challenges ... Rice (Oryza sativa) is one of the most important staple food crops for more than half of the world's population. The demand is increasing for food security because of population growth and environmental challenges triggered by climate changes. This scenario has led to more interest in developing crops with greater productivity and sustainability. The process of genetic transformation, a major tool for crop improvement, utilizes promoters as one of its key elements. Those promoters are generally divided into three types: constitutive, spatiotemporal, and condition-dependent. Tran- scriptional control of a constitutive promoter often leads to reduced plant growth, due to a negative effect of accumu- lated molecules during cellular functions or energy consump- tion. To maximize the effect of a transgene on transgenic plants, it is better to use condition-dependent or tissue- specific promoters. However, until now, those types have not been as widely applied in crop biotechnology. In this review, we introduce and discuss four groups of tissue-specific promoters (5o promoters in total) and six groups of condition-dependent promoters (27 promoters). These pro- moters can be utilized to fine-tune desirable agronomic traits and develop crops with tolerance to various stresses, enhanced nutritional value, and advanced productivity. 展开更多
关键词 condition-dependent promoters crop biotechnologyapplication genetic transformation RICE tissue-specific promoters
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Ecophysiology of egg rejection in hosts of avian brood parasites:new insights and perspectives 被引量:1
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作者 Francisco RUIZ-RAYA 《Current Zoology》 SCIE CAS CSCD 2021年第6期631-638,共8页
Egg rejection is the most effective and widespread defense used by host species to counteract the extreme fitness costs frequently imposed by obligate avian brood parasites.Yet,the proximate mechanisms underlying betw... Egg rejection is the most effective and widespread defense used by host species to counteract the extreme fitness costs frequently imposed by obligate avian brood parasites.Yet,the proximate mechanisms underlying between-and within-individual variation in host responses remain poorly explored.Emerging evidence suggests that egg rejection is dependent on individual physiological states,and draws attention to the role of hormones as mediators of flexible antiparasitic responses.In this perspective article,I outline recent advances in our understanding of the proximate factors that mediate egg rejection.I also point out some areas where knowledge remains still lacking,especially those related to the development and maintenance of effective cognitive functions,the potential role of oxidative stress,immunological state,and developmental stressors.I propose new hypotheses that stimulate future research on behavioral host responses toward brood parasitism. 展开更多
关键词 cognitive performance condition-dependence CORTICOSTERONE flexible responses PROLACTIN
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Complex courtship success and plasticity environments displays facilitate in signaling across male reproductive variable
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作者 Dustin J. WILGERS Eileen A. HEBETS 《Current Zoology》 SCIE CAS CSCD 北大核心 2011年第2期175-186,共12页
Effective signal transmission is essential for communication. In environments where signal transmission is highly variable, signalers may utilize complex signals, which incorporate multiple components and modalities, ... Effective signal transmission is essential for communication. In environments where signal transmission is highly variable, signalers may utilize complex signals, which incorporate multiple components and modalities, to maintain effective communication. Male Rabidosa rabida wolf spiders produce complex courtship signals, consisting of both visual and seismic components. We test the hypothesis that the complex signaling of R. rabida contributes to male reproductive success in variable signaling environments. We first examine the condition-dependence of foreleg ornamentation (a presumed visual signal) and seismic signal components and find that both may provide potentially redundant information on foraging history. Next, we assessed reproductive success across manipulated signaling environments that varied in the effectiveness of visual and/or seismic signal transmission. In environments where only one signal could be successfully transmitted (e.g., visual or seismic), pairs were still able to successfully copulate. Additionally, we found that males altered their courtship display depending on the current signaling environment. Specifically, males reduced their use of a visual display component in signaling environments where visual signal transmission was ablated. Incorporating signals in multiple modalities not only enables R. rabida males to maintain copulation success across variable signaling environments, but it also enables males to adjust their composite courtship display to current signaling conditions . 展开更多
关键词 Communication Multimodal Signal evolution condition-dependent LYCOSIDAE Rabidosa rabida Efficacy back-up Redundant signals
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Feather content of porphyrins in Eurasian eagle owl(Bubo bubo)fledglings depends on body condition and breeding site quality
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作者 Ismael GALVÁN María del Mar DELGADO +3 位作者 Pablo RCAMARERO Rafael MATEO RuiLOURENÇO Vincenzo PENTERIANI 《Integrative Zoology》 SCIE CSCD 2018年第5期569-578,共10页
Porphyrins are pigments produced in most animal cells during the synthesis of heme,but their importance for external coloration is unclear.Owls(Order Strigiformes)are among the few animals that accumulate porphyrins i... Porphyrins are pigments produced in most animal cells during the synthesis of heme,but their importance for external coloration is unclear.Owls(Order Strigiformes)are among the few animals that accumulate porphyrins in the integument,where it could serve as a means of signaling.Here we hypothesized that the porphyrin content of feathers may depend on body condition and breeding site quality in Eurasian eagle owl(Bubo bubo)fledglings and,thus,constitute amplifiers of the quality of the area where they are born.Using high-performance liquid chromatography,we found 2 porphyrins(protoporphyrin IX and coproporphyrin III)in the body feathers of 19 eagle owl fledglings from 7 breeding territories.Coproporphyrin III,but not protoporphyrin IX feather concentration,was positively associated with the body mass of fledglings and with the quality of the breeding sites where they were reared with respect to food quality and availability.As coproporphyrin III is produced under oxidative stress,we suggest that good breeding sites may lead to fledglings in good condition.This,in turn,may make fledglings induce a certain level of free radical and coproporphyrin III production to signal to conspecifics their site-mediated capacity to cope with oxidative stress.This is the first time that porphyrin content in the integument has been found to be related to individual quality,opening a new scenario for studying evolution of animal coloration. 展开更多
关键词 AMPLIFIERS condition-dependENCE eagle owl FLUORESCENCE PORPHYRINS
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