Results 21 to 30 of about 8,113 (174)
Design of constant voltage and constant current switching power supply [PDF]
, 2015 随着电子科技日新月异的发展，每家每户使用的电器设备越来越多，而电器设备往往需要合适的电源来驱动。特别是带有锂电池的离线设备，比如吸尘器、电动车、手机、数码相机等需要高精度的恒压恒流的充电器，使之合理的充电曲线保证锂电池的充电安全和寿命。 开关电源因其小体积、低功耗、高可靠性、高效率等诸多优点受到广泛的关注。开关电源是通过PWM信号控制MOS器件开和关，使输入连续的直流电变成间断的脉冲，再通过电容电感储能滤波，将间断的脉冲滤成连续的直流电。从而可知，只要调节MOS器件的开 ...
林明威
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Harnessing social media data to track species range shifts
Conservation Biology, EarlyView.Abstract Biodiversity monitoring programs and citizen science data remain heavily biased toward the Global North. Especially in megadiverse countries with limited biodiversity records, incorporating social media data can help address existing data gaps.
Shawan Chowdhury +15 more
wiley +1 more source
Rare Metals, Volume 45, Issue 4, April 2026.ABSTRACT The rapid advancement of 5G communication technology has intensified electromagnetic pollution, creating an urgent demand for flexible multifunctional fabrics with efficient electromagnetic interference (EMI) shielding performance. This study proposes a novel material‐stacked construction strategy to fabricate multifunctional MXene/cellulose ...
Zong‐Kai Yan +9 more
wiley +1 more source
Study on Nutrient Dynamics and Ecological Process in a Subtropical Reservoir [PDF]
, 2016 由于梯级电站大量开发，河流湖库化和富营养化问题突出，但有关库区营养盐动态和生态过程缺乏系统性研究。本文以九龙江北溪西陂水库为研究对象，开展入库河流和水库的综合观测，从时、日、月、季节多个时间尺度捕捉营养盐和生态参数的变化，分析水库营养盐和浮游植物的季节转换模式、暴雨事件生态响应过程和机制，总结季风气候条件下亚热带不同水库营养盐和生态特征。主要研究结论如下： （1）西陂水库营养盐在干湿季节过渡期，NH4-N、DRP的相对富集和水温升高导致叶绿素a出现峰值。水库汇水与水面面积比值高达7285 ...
莫琼利
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Rare Metals, Volume 45, Issue 4, April 2026.ABSTRACT To address the issues of aluminum (Al) powder agglomeration during combustion and low oxidizer decomposition efficiency in composite solid propellants, this study utilized in situ self‐assembly technology to prepare cobalt‐based hybrid‐coated modified Al powder (Al@CZ).
Chong Chen +11 more
wiley +1 more source
Major and trace-element zoning in metamorphic garnets and their metamorphic process implications [PDF]
, 2003 This article introduces some of the modern techniques for analyzing compositional zonings/profiles in metamorphic garnet, emphasizing the significance of two-dimensional composition X-ray mapping for such investigations.
Chen, NS +4 more
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Highly Anisotropic TbCo11Ti: Phase Evolution, Microstructure and Magnetic Properties
Rare Metals, Volume 45, Issue 3, March 2026.ABSTRACT Among the 1:12‐type compounds, TbCo11Ti stands out due to its high Curie temperature and pronounced magnetocrystalline anisotropy. However, its magnetic behavior at room temperature and its phase evolution process have not been clearly established.
Wei Chen +11 more
wiley +1 more source
Research and Design of Multi-Channel Temperature Control System for High Power LEDs Online Accelerated Aging [PDF]
, 2016 半导体照明技术伴随时代的进步，应用愈发广泛，大功率LED照明领域更是逐步走向普及。但实际应用中，LED器件和封装的缺陷及工作时发热极大限制了其性能和实际寿命，可靠性问题日渐显露。为此LED寿命加速测试尤为重要，以实现寿命预测，失效机理分析，使得LED可靠性提升。常用的高温老化测试传统上使用高温试验箱，此方法存在诸多缺点：参数检测不连续、温升慢、体积大、功耗高。本文针对性地研制了一套轻便的LED在线寿命加速多路温控系统（以下简称温控系统）。主要工作内容与研究成果如下： 1.研制了温控系统的硬件部分 ...
周骁炀
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, 2018 为评估气候变化及实施减排政策对中国海洋经济的影响,本文构建了中国海洋经济社会经济核算矩阵(marine social accounting matrix,MSAM),并以此为数据基础构建中国海洋经济可计算一般均衡(computable general equilibrium,CGE)模型,并将该模型与气候变化影响模型相结合,从而实现了从气候变化对自然系统的影响到对经济系统影响的转化。论文设计了实施和不实施温室气体减排两种政策时的可能的6种气候变化情景。各情景的模拟分析表明 ...
刘容子, 孔昊, 张平, 彭本荣
core +1 more source
Rare Metals, Volume 45, Issue 3, March 2026.ABSTRACT The development of efficient and stable bifunctional catalysts remains a key challenge for green hydrogen production via electrochemical water splitting. In this study, a bimetallic Mo/Fe‐doped CoP2 nanoleaf array anchored on carbon cloth (Mo, Fe‐CoP2@CC) was synthesized from zeolitic imidazolate framework‐L (ZIF‐L) via an ion‐exchange and low‐
Xiangqun Zeng +6 more
wiley +1 more source