In many rural areas the management of natural resources is confronted with the tragedy of the common problem;not only historically but also in modern times. Especially where biodiversity loss appears and ecosystem ser...In many rural areas the management of natural resources is confronted with the tragedy of the common problem;not only historically but also in modern times. Especially where biodiversity loss appears and ecosystem services (ESS) decline, the lack of public management might be related to inappropriate institutional setups. Two distinct directions of thought prevail on the subject. On one hand, proponents of property rights and minimal state intervention eagerly analyse the feat of modern institutions and view private property and payments for ecosystem services (PES) as solution. On the other hand, common pool resource management (CPM) has regained interest because nature is not a straight commodity and cooperation in ESS provision is needed (partly also to facilitate PES). In this paper, the two aspects are combined in a hybrid institution. We suggest a new way of approaching institutional questions in ESS provision as synthesis of private and publically controlled ESS provision. It is contemplated as ESS governance of local eco-nets given the potential for inclusion of public management. In principle, the result is a controlled framework of land sharing between farm land (private ownership) and communally managed?land (public ownership). Some land is devoted to hedges, wetlands, etc. Land is an immobile resource and can be used for EESs based on planned species prevalence, whereas communities compete also for labour which can move (or not). Governance is acting in competing constituencies and is a mean to control the regulating entities (public ESS management). At a meta-level we combine the need for public management with advantages of a competitive neo-classical framework. This contribution to CPM investigates a model of a group whose well-being is based on ESS provision in a cultural landscape. By statutory regulations, land (field margins), is ex-tracted from farms for ESS;in particular a leader (called reeve) guides farmers. Two institutions are compared: (1) labour in public land for ESS based farming (i.e.?it is controlled by public authority), or (2) it can migrate seeking higher rents in neighbouring communities.展开更多
Gonadal function in fish, CJprinus carpio was significantly affected by sublethal doses of mercuric chloride (HgCl2 ) and cadmium chloride (CdCl2 ) in chronic (45 days ) exposure.Parameters investigated were nonesteri...Gonadal function in fish, CJprinus carpio was significantly affected by sublethal doses of mercuric chloride (HgCl2 ) and cadmium chloride (CdCl2 ) in chronic (45 days ) exposure.Parameters investigated were nonesterified (NE) and esterified (E) cholestcrol of ovary,liver and serum and ovarian 3β-Hydroxysteroid and 17β-Hydroxysteroid dehyrogenaseenzyme activity and serum and pituitary gonadotropin (GtH) levels. Both the pollutantswere able to reduce the hypothalamic extract (HE) or gonadotropin releasing hormone(GnRH) induced pituitary GtH release in vitro. Short term (96h) exposure of the fish tothe pollutants had no significant effect on the gonadal function. ln addition to thedeleterious effect of pollutants on the gonadal steroidogenesis and pituitary gonadotropin release, using [4-14C] cholesterol as a tracer it was found that for 45 days expeure, HgCl2'had an adverse effect on the transport of cholesterol from circulation to ovary.展开更多
目的 探讨基于自我调节常识模型(The Common-Sense Model of Self-Regulation,CSM)的中青年冠心病经皮冠状动脉介入术(percutaneous coronary intervention,PCI)后患者干预方案的设计、实施方法及效果。方法 选取2021年7月—2022年7月...目的 探讨基于自我调节常识模型(The Common-Sense Model of Self-Regulation,CSM)的中青年冠心病经皮冠状动脉介入术(percutaneous coronary intervention,PCI)后患者干预方案的设计、实施方法及效果。方法 选取2021年7月—2022年7月收治的中青年PCI术后患者112例作为研究对象,其中2021年7月—2021年12月入院的57例患者为对照组,2022年1月—7月入院的55例患者为试验组。试验组根据CSM在认知阶段、应答阶段、评估阶段、行为及疾病结局阶段对PCI术后患者的自我管理、疾病感知及心理进行干预;对照组采取PCI术后常规护理。比较两组干预前、干预3个月后的自我管理行为、疾病感知、焦虑评分。结果 干预3个月后,试验组冠心病自我管理行为得分高于对照组(t=6.221,P<0.001);疾病感知得分、焦虑得分均低于对照组(t=3.284,6.949;P<0.05)。结论 基于CSM的干预可提高中青年冠心病PCI术后患者自我管理能力,降低负性疾病感知及负性情绪,减轻患者身心负担。展开更多
该文提出一种基于波动功率解耦的模块化多电平换流器(ripple-power decoupling based modular multilevel converter,RPD-MMC)电机调速系统,通过半桥与变压器结构的高频链将子模块(submodule,SM)隔离后进行横向互联,实现三相波动功率在S...该文提出一种基于波动功率解耦的模块化多电平换流器(ripple-power decoupling based modular multilevel converter,RPD-MMC)电机调速系统,通过半桥与变压器结构的高频链将子模块(submodule,SM)隔离后进行横向互联,实现三相波动功率在SM电容中的解耦,进而消除共模电压(common-mode voltage,CMV)低频波动分量;并提出一种脉冲优化控制CPS-SPWM(pulse optimization control CPS-SPWM,POC-CPS-SPWM)策略,控制任一时刻MMC三相的上、下桥臂导通SM个数保持一致,消除CMV高频波动分量,最终实现对CMV的完全消除。该文从CMV的机理与特性分析出发,分别对低频与高频抑制的方案提出、原理分析与效果实现进行探讨,最后通过仿真与实验,验证CMV机理分析与两种策略消除CMV的可行性与有效性。展开更多
文摘In many rural areas the management of natural resources is confronted with the tragedy of the common problem;not only historically but also in modern times. Especially where biodiversity loss appears and ecosystem services (ESS) decline, the lack of public management might be related to inappropriate institutional setups. Two distinct directions of thought prevail on the subject. On one hand, proponents of property rights and minimal state intervention eagerly analyse the feat of modern institutions and view private property and payments for ecosystem services (PES) as solution. On the other hand, common pool resource management (CPM) has regained interest because nature is not a straight commodity and cooperation in ESS provision is needed (partly also to facilitate PES). In this paper, the two aspects are combined in a hybrid institution. We suggest a new way of approaching institutional questions in ESS provision as synthesis of private and publically controlled ESS provision. It is contemplated as ESS governance of local eco-nets given the potential for inclusion of public management. In principle, the result is a controlled framework of land sharing between farm land (private ownership) and communally managed?land (public ownership). Some land is devoted to hedges, wetlands, etc. Land is an immobile resource and can be used for EESs based on planned species prevalence, whereas communities compete also for labour which can move (or not). Governance is acting in competing constituencies and is a mean to control the regulating entities (public ESS management). At a meta-level we combine the need for public management with advantages of a competitive neo-classical framework. This contribution to CPM investigates a model of a group whose well-being is based on ESS provision in a cultural landscape. By statutory regulations, land (field margins), is ex-tracted from farms for ESS;in particular a leader (called reeve) guides farmers. Two institutions are compared: (1) labour in public land for ESS based farming (i.e.?it is controlled by public authority), or (2) it can migrate seeking higher rents in neighbouring communities.
文摘Gonadal function in fish, CJprinus carpio was significantly affected by sublethal doses of mercuric chloride (HgCl2 ) and cadmium chloride (CdCl2 ) in chronic (45 days ) exposure.Parameters investigated were nonesterified (NE) and esterified (E) cholestcrol of ovary,liver and serum and ovarian 3β-Hydroxysteroid and 17β-Hydroxysteroid dehyrogenaseenzyme activity and serum and pituitary gonadotropin (GtH) levels. Both the pollutantswere able to reduce the hypothalamic extract (HE) or gonadotropin releasing hormone(GnRH) induced pituitary GtH release in vitro. Short term (96h) exposure of the fish tothe pollutants had no significant effect on the gonadal function. ln addition to thedeleterious effect of pollutants on the gonadal steroidogenesis and pituitary gonadotropin release, using [4-14C] cholesterol as a tracer it was found that for 45 days expeure, HgCl2'had an adverse effect on the transport of cholesterol from circulation to ovary.
文摘该文提出一种基于波动功率解耦的模块化多电平换流器(ripple-power decoupling based modular multilevel converter,RPD-MMC)电机调速系统,通过半桥与变压器结构的高频链将子模块(submodule,SM)隔离后进行横向互联,实现三相波动功率在SM电容中的解耦,进而消除共模电压(common-mode voltage,CMV)低频波动分量;并提出一种脉冲优化控制CPS-SPWM(pulse optimization control CPS-SPWM,POC-CPS-SPWM)策略,控制任一时刻MMC三相的上、下桥臂导通SM个数保持一致,消除CMV高频波动分量,最终实现对CMV的完全消除。该文从CMV的机理与特性分析出发,分别对低频与高频抑制的方案提出、原理分析与效果实现进行探讨,最后通过仿真与实验,验证CMV机理分析与两种策略消除CMV的可行性与有效性。
