检索结果-南通市图书馆

The Origin and Nature of the Planck Constant

Journal of High Energy Physics, Gravitation and Cosmology 2021年第1期7卷 324-332页

作者： Nader Butto dania Petah-Tikva Israel

Planck’s constant h is a fundamental physical constant defined in the realm of quantum theory and is determined only by physical measurement and cannot be calculated. To this day, physicists do not have a convincing explanation for why action in microcosm is quantized or why h has a specific quantitative value. Here, a new theory is presented based on the idea that the elementary particles are vortices of a condensed superfluid vacuum. The vortex has a conserved angular momentum that can be calculated by applying hydrodynamic laws;in this way, the numerical value of Planck’s constant can be obtained. Therefore, the Planck constant is not a fundamental constant but an observable parameter of the elementary particle as a vortex that has constant vorticity and conserved angular momentum. This theory may offer a unique and comprehensive understanding of Planck’s constant and open a new perspective for a theory of everything.

关键词： Planck’s Constant Angular Momentum Compton Radius Vorticity

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Baseline Levels of <i>Siderastrea siderea</i>Bleaching under Normal Environmental Conditions in Little Cayman

引用

Open Journal of Marine Science 2017年第1期7卷 142-154页

作者： Samantha Banks Kristi Foster University of Redlands Redlands CA USA Coastal & Marine Ecology Consultants Dania Beach FL USA

This study describes the health status of Siderastrea siderea in Little Cayman before, during, and after the 2015 Caribbean-wide elevated temperature anomaly. Colony color was used as a proxy for health during snorkel and scuba surveys of shallow (°C, S. siderea were early indicators of reef stress and among the first corals to bleach. Depth and site resilience did not significantly impact temperature susceptibility;however, smaller colonies (2 surface area) were more likely to change color than the larger size classes. Little Cayman’s S. siderea were capable of surviving large-scale (>80%) bleaching: mortality was observed for only one colony. Resilience rates varied considerably: one-third of the impacted population returned to the normal brown color within two months, one-third required 3 - 9 months to recover, and the fates of the remaining one-third remain to be determined. If the return to normal color is indicative of resistance to reef disturbances, S. siderea may be among the “winning” coral species following elevated temperature anomalies which are predicted to occur with increasing frequency and severity as a result of climate change.

关键词： Siderastrea siderea Bleaching Events Demographic Study Little Cayman Caribbean

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Coral Assemblages in the Southeastern Arabian Gulf (Qatar and Abu Dhabi, UAE): Various Stages of <i>Acropora</i>Recovery a Decade after Recurrent Elevated Temperature Anomalies

引用

Open Journal of Marine Science 2013年第2期3卷 28-39页

作者： Kristi A. Foster Greg Foster Suaad Al-Harthi Environment Agency-Abu Dhabi Abu Dhabi United Arab Emirates Nova Southeastern University Oceanographic Center Dania Beach USA

This study describes the coral communities near Qatarand Abu Dhabi (UAE) ten years after the recurrent elevated temperature anomalies of 1996, 1998 and 2002 which resulted in the mass mortality of Acropora spp. Data derived from photo transects taken over a four-year period were analyzed to characterize the existing coral communities, to compare these to the pre- and post-disturbance communities in the adjacent waters near Dubai, and to project the time-frames required for the communities to return to pre-disturbance levels. The massive corals, dominated by Porites spp. and faviids, showed no long-terms affects associated with exposures to the three thermal anomalies;whereas acroporids, comprising 0% - 8% of the live coral cover, were in various stages of recovery. Projections indicated that acroporid regeneration will require 15 - 32 years to achieve the ≥40% pre-disturbance area cover. The existing communities are too small in size and number to be self-seeding;thus, they are dependent upon the recruitment of larvae from remote refuges of colonies that survived the thermal anomalies. Efforts to identify these refuges and to establish appropriate multi-national conservation programs shall become critical to the future survival of acroporids throughout the southeasternArabian Gulfas the projected regeneration times exceed the periods between disturbances, which are expected to occur more frequently as a result of global climate change.

关键词： Coral Community Elevated Temperature Anomaly Mass Mortality Acropora Arabian Gulf Recovery

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：