Results 11 to 20 of about 6,391 (157)
Zhongguo shiyan zhenduanxue, 2021 维生素D对机体钙磷代谢、细胞生长和分化方面具有十分重要的作用。近几十年来研究证实糖脂代谢、炎症反应及免疫调节等生物过程均有维生素D的参与。机体几乎所有细胞均具有维生素D受体(Vitamin D receptor,VDR),如:心肌细胞、胰腺细胞、脂肪细胞等,维生素D通过与VDR结合,在机体中发挥调节作用。维生素D介导了多种疾病的发病。大量研究证实,维生素D在糖代谢疾病的发病中具有重要作用。维生素D对胰岛β细胞还有保护作用,是胰岛β细胞的保护因子之一,对机体血糖平衡和胰岛素的合成分泌过程具有重要作用。
王蘇弘 +4 more
doaj
Design of a PFM Boost LED driver [PDF]
, 2006 本文针对电视、显示器背光、太阳能LED路灯等需要大功率输出及高驱动电压的应用场合，采用PFM双环控制技术解决了Boost开关电源固有的稳定性问题，设计了一款高效率、多负载及具有多种保护功能的大功率PFM升压型驱动芯片。 论文设计了外部电压反馈、内部电流控制的PFM控制电路结构，实现了稳定的无需谐波补偿的Boost开关电源结构，提高了芯片转化效率；提出用负载电容等效串联电阻的电压突变特性控制功率管输出的方法，实现了PFM的工作模式，达到电流的精确控制；采用延时控制模块对输出电平进行监测 ...
王婷玉
core +3 more sources
Current Status and Prospect of Membrane-Based Offshore Floating Photovoltaic Technology [PDF]
, 2023 [Introduction] The research and development of offshore floating photovoltaic complies with the needs of national energy strategic development, caters to the background of industry development led by science and technology, and helps the development of ...
Bo LIU, Gang LI, Hong QIAO, Jiping CHEN
core +1 more source
Protected area downgrading, downsizing, and degazettement as a threat to iconic protected areas
Conservation Biology, Volume 33, Issue 6, Page 1275-1285, December 2019., 2019 Abstract Protected areas (PAs) are expected to conserve nature and provide ecosystem services in perpetuity, yet widespread protected area downgrading, downsizing, and degazettement (PADDD) may compromise these objectives. Even iconic protected areas are vulnerable to PADDD, although these PADDD events are often unrecognized.
Siyu Qin +7 more
wiley +1 more source
Design And Implementation of Material Management Information System of Electric Power Enterprises [PDF]
, 2015 现代社会的科技发展与计算机和网络术密不可分。信息化已成为了一种趋势，对社会的发展与进步有很好的推动作用。信息化技术主要有系统开发技术、基础技术、应用技术三个层面。随着网络通信，电子商务、多媒体等技术不断创新和进步，网络应用也越来越普及，我们的日常生活和买卖生产方式都有了很大的改变。发电企业也展开了信息化管理的建设。并且在这前提下，开始了发电企业信息管理系统的建设。发电企业通过信息化工程的建设，从而达到了对发电企业资金收支、物资预算编制的信息化管理，并完善了发电企业物资管理信息化体系的建设 ...
刘军
core
Poverty, Charity, and Hunger Among Families With Children—An Australian Example
Poverty &Public Policy, Volume 17, Issue 2, June 2025.ABSTRACT In Australia, poverty, hunger, and food insecurity are a reality for many households, but much of the research considers the adult population of households, rarely considering the specific experiences of households with dependent children.
Fiona H. McKay +2 more
wiley +1 more source
, 2000 二次电池均有密封“免维护”的要求。密封二次电池发展至今，最大的问题之一就是气体内压问题，电池充放电过程中产生的气体是多种电池普遍存在的问题，从铅酸蓄电池到碱性电池，比如镍金属氢化物电池、镉镍电池、锌镍电池等，以及新兴发展的聚合物锂离子电池，都存在电池析气的现象。 电池内压变化是评价电池综合性能优劣的重要参数之一。电池内压过高会造成电池漏液，影响电池的充电效率、封口化成条件、放电性能和循环寿命，甚至电池的安全运行。对二次电池充放电过程中气体内压变化的研究引起了人们的普遍关注 ...
张英春
core
Threats posed by land use to water quality in South Africa's strategic water source areas
World Water Policy, Volume 11, Issue 1, Page 155-164, February 2025.Abstract Understanding the negative impacts of land use/land cover (LULC) on water quality is key to developing effective integrated catchment management strategies. However, in line with the Integrated Water Resources Management (IWRM) philosophy, this necessitates the generation and application of useful scientific knowledge, which stakeholders and ...
Kent Anson Locke, Kevin Winter
wiley +1 more source
Study on the gas generation in Polymer Lithium-ion Battery [PDF]
, 2004 锂离子电池在首次充电的过程中，随着SEI层的形成，电解液溶剂会发生还原分解，从而产生气体。此外，由于电池外包装材料的密封性不好，或电池在生产过程中引入一些杂质，也会造成电池在储存阶段发生气胀。这些问题，长期以来一直是锂离子电池产业化进程的困扰因素之一。目前，人们对SEI层的机理研究相对较多，而影响SEI层性质的各种因素研究较少，尤其是对锂离子电池产气机理的研究更少。 通常人们主要是从溶剂的粘度、介电常数、凝固点以及沸点等方面出发，来考察组成的电解液溶剂体系的电导率以及对电池温度性能的影响。但在实际工作中，
黄丽
core
M̓ṇúxvʔit model for centering Indigenous knowledge and governance
Conservation Biology, Volume 38, Issue 6, December 2024.Abstract The importance of Indigenous (and local) knowledge and governance systems for addressing social and ecological crises is increasingly recognized. Unfortunately, attempts to incorporate Indigenous knowledge into Western approaches, often without the full leadership, consent, and participation of the peoples holding those knowledges, can cause ...
Elroy White (Q̓íx̌itasu) +5 more
wiley +1 more source