2019年中国的石油对外依存度比例为72%,同时机动车尾气排放也是造成空气污染的重要来源。基于这样的现状,推进交通领域的电气化进程,对中国的能源转型具有重要的战略意义。根据国家信息中心统计数字,2019年中国电动汽车(包含纯电动汽车...2019年中国的石油对外依存度比例为72%,同时机动车尾气排放也是造成空气污染的重要来源。基于这样的现状,推进交通领域的电气化进程,对中国的能源转型具有重要的战略意义。根据国家信息中心统计数字,2019年中国电动汽车(包含纯电动汽车与混合动力汽车)销量达到了120万辆,是全球最大电动汽车市场。随着电力电子技术的不断进步,将电动汽车作为一种新型的储能设施,通过V2G模式(vehicle to grid)实现与电网之间的电能量双向流动,可以成为提高电网调节能力与供电可靠性的一种重要方式。本文对V2G在电网的应用进行了梳理,并基于目前的电价政策以及动力电池成本,对V2G服务的提供主体参与各类应用的收益和成本基于算例进行了分析。V2G模式的经济性受电价政策影响很大,并且与电力现货市场以及配套的辅助服务市场的成熟度相关。未来V2G的推广还有赖于合理的电力市场准入门槛和电价补偿机制的设计。展开更多
Stress can be associated with many physiologicalchanges resulting in significant decrements in human performance.Due to growing interests in alternative and complementary medicine by Westerners,many of the traditions ...Stress can be associated with many physiologicalchanges resulting in significant decrements in human performance.Due to growing interests in alternative and complementary medicine by Westerners,many of the traditions and holistic yogic breathing practices today are being utilized as a measure for healthier lifestyles.These state-of-the-art practices can have a significant impact on common mental health conditions such as depression and generalized anxiety disorder.However,the potential of yogic breathing on optimizing human performance and overall well-being is not well known.Breathing techniques such as alternate nostril,Sudarshan Kriya and bhastrika utilizes rhythmic breathing to guide practitioners into a deep meditative state of relaxation and promote self-awareness.Furthermore,yogic breathing is physiologically stimulating and can be described as a natural"technological"solution to optimize human performance which can be categorized into:(1)cognitive function(i.e.,mind,vigilance);and(2)physical performance(i.e.,cardiorespiratory,metabolism,exercise,whole body).Based on previous studies,we postulate that daily practice of breathing meditation techniques play a significant role in preserving the compensatory mechanisms available to sustain physiological function.This preservation of physiological function may help to offset the time associated with reaching a threshold for clinical expression of chronic state(i.e.,hypertension,depression,dementia)or acute state(i.e.,massive hemorrhage,panic attic)of medical conditions.However,additional rigorous biomedical research is needed to evaluate the physiological mechanisms of various forms of meditation(i.e.,breath-based,mantra,mindfulness)on human performance.These efforts will help to define how compensatory reserve mechanisms of cardiovascular and immune systems are modulated by breath-based meditation.While it has been suggested that breath-based meditation is easier for beginning practitioners when compared to other forms of meditation more research is needed to 展开更多
Since COS in IVF creates the multiple follicle development which result in the rapid increase of E2 level and sensitivity to pituitary,reduce the bioactivity of GnSAF,bring about the premature LH surge occurren.It wou...Since COS in IVF creates the multiple follicle development which result in the rapid increase of E2 level and sensitivity to pituitary,reduce the bioactivity of GnSAF,bring about the premature LH surge occurren.It would harm the oocyte quality,which can be prevented by administration of GnRH-a.GnRH-a competes to occupy the receptor on pituitary.Thus,pituitary became desensitization clinically called as pituitary down regulation.It has been routinely used in COS for more than twenty years.However,the high dose of GnRH-a strongly inhibits the pituitary ovary axe,and led to the super suppress of ovarian response.The low dose of the GnRH-a or GnRHant has been recommended nowadays.Ovarian response is important for ART,so many indexes to evaluate the ovarian reserve.Some of them are available,such as age,FSH and AFC.For poor responder,the first experience of COS is the best evidence.Asymmetry follicle development and poor ovarian reserve are the most common in poor responder.The former can be adjusted by down regulation protocol and Gn dose administration,the later may take the oocyte donation into consideration.展开更多
In recent years,the interconnection of asynchronous power grids through the VSC-MTDC system has been proposed and extensively studied in light of the potential benefits of economical bulk power exchanges and frequency...In recent years,the interconnection of asynchronous power grids through the VSC-MTDC system has been proposed and extensively studied in light of the potential benefits of economical bulk power exchanges and frequency regulation reserves sharing.This paper proposes an optimized allocation method for sharing frequency regulation reserves among the interconnected power systems and the corresponding frequency regulation control of the VSC-MTDC system under emergency frequency deviation events.First,the frequency regulation reserve classification is proposed.In the classification,the available frequency response capacity reserves of each interconnection are divided into commercial reserves and regular reserves.While the commercial reserves are procured through long-term contracts,the regular reserves are purchased based on market prices of frequency regulation services.Secondly,based on the proposed frequency regulation reserve classification,a novel frequency regulation control is then introduced for the VSC-MTDC system.This control method could minimize the costs of the disturbed power grid for the needed frequency response supports from the other power grids.Simulation verifications are performed on a modified IEEE 39 bus system and a highly reduced power system model representing the North American grids.The simulation verification indicates that the developed frequency regulation control significantly reduced ancillary service costs of the disturbed power grid.展开更多
文摘2019年中国的石油对外依存度比例为72%,同时机动车尾气排放也是造成空气污染的重要来源。基于这样的现状,推进交通领域的电气化进程,对中国的能源转型具有重要的战略意义。根据国家信息中心统计数字,2019年中国电动汽车(包含纯电动汽车与混合动力汽车)销量达到了120万辆,是全球最大电动汽车市场。随着电力电子技术的不断进步,将电动汽车作为一种新型的储能设施,通过V2G模式(vehicle to grid)实现与电网之间的电能量双向流动,可以成为提高电网调节能力与供电可靠性的一种重要方式。本文对V2G在电网的应用进行了梳理,并基于目前的电价政策以及动力电池成本,对V2G服务的提供主体参与各类应用的收益和成本基于算例进行了分析。V2G模式的经济性受电价政策影响很大,并且与电力现货市场以及配套的辅助服务市场的成熟度相关。未来V2G的推广还有赖于合理的电力市场准入门槛和电价补偿机制的设计。
文摘Stress can be associated with many physiologicalchanges resulting in significant decrements in human performance.Due to growing interests in alternative and complementary medicine by Westerners,many of the traditions and holistic yogic breathing practices today are being utilized as a measure for healthier lifestyles.These state-of-the-art practices can have a significant impact on common mental health conditions such as depression and generalized anxiety disorder.However,the potential of yogic breathing on optimizing human performance and overall well-being is not well known.Breathing techniques such as alternate nostril,Sudarshan Kriya and bhastrika utilizes rhythmic breathing to guide practitioners into a deep meditative state of relaxation and promote self-awareness.Furthermore,yogic breathing is physiologically stimulating and can be described as a natural"technological"solution to optimize human performance which can be categorized into:(1)cognitive function(i.e.,mind,vigilance);and(2)physical performance(i.e.,cardiorespiratory,metabolism,exercise,whole body).Based on previous studies,we postulate that daily practice of breathing meditation techniques play a significant role in preserving the compensatory mechanisms available to sustain physiological function.This preservation of physiological function may help to offset the time associated with reaching a threshold for clinical expression of chronic state(i.e.,hypertension,depression,dementia)or acute state(i.e.,massive hemorrhage,panic attic)of medical conditions.However,additional rigorous biomedical research is needed to evaluate the physiological mechanisms of various forms of meditation(i.e.,breath-based,mantra,mindfulness)on human performance.These efforts will help to define how compensatory reserve mechanisms of cardiovascular and immune systems are modulated by breath-based meditation.While it has been suggested that breath-based meditation is easier for beginning practitioners when compared to other forms of meditation more research is needed to
文摘Since COS in IVF creates the multiple follicle development which result in the rapid increase of E2 level and sensitivity to pituitary,reduce the bioactivity of GnSAF,bring about the premature LH surge occurren.It would harm the oocyte quality,which can be prevented by administration of GnRH-a.GnRH-a competes to occupy the receptor on pituitary.Thus,pituitary became desensitization clinically called as pituitary down regulation.It has been routinely used in COS for more than twenty years.However,the high dose of GnRH-a strongly inhibits the pituitary ovary axe,and led to the super suppress of ovarian response.The low dose of the GnRH-a or GnRHant has been recommended nowadays.Ovarian response is important for ART,so many indexes to evaluate the ovarian reserve.Some of them are available,such as age,FSH and AFC.For poor responder,the first experience of COS is the best evidence.Asymmetry follicle development and poor ovarian reserve are the most common in poor responder.The former can be adjusted by down regulation protocol and Gn dose administration,the later may take the oocyte donation into consideration.
基金This work was supported in part by the Young Innovative Talents Project of Universities and Colleges in Guangdong Province under Grant 2021KQNCX002in part by the Talent Team Building Funds of SCUT under Grant D6211230.
文摘In recent years,the interconnection of asynchronous power grids through the VSC-MTDC system has been proposed and extensively studied in light of the potential benefits of economical bulk power exchanges and frequency regulation reserves sharing.This paper proposes an optimized allocation method for sharing frequency regulation reserves among the interconnected power systems and the corresponding frequency regulation control of the VSC-MTDC system under emergency frequency deviation events.First,the frequency regulation reserve classification is proposed.In the classification,the available frequency response capacity reserves of each interconnection are divided into commercial reserves and regular reserves.While the commercial reserves are procured through long-term contracts,the regular reserves are purchased based on market prices of frequency regulation services.Secondly,based on the proposed frequency regulation reserve classification,a novel frequency regulation control is then introduced for the VSC-MTDC system.This control method could minimize the costs of the disturbed power grid for the needed frequency response supports from the other power grids.Simulation verifications are performed on a modified IEEE 39 bus system and a highly reduced power system model representing the North American grids.The simulation verification indicates that the developed frequency regulation control significantly reduced ancillary service costs of the disturbed power grid.
