Results 21 to 30 of about 22,750 (171)
Comprehensive Error Model and Experimental Research of Large Aperture Optics Measurement Platform [PDF]
, 2015 大口径高精度光学元件，特别是非球面光学元件，已经广泛应用于航空航天、天文及惯性约束聚变(ICF)激光装置等国家重大工程中，特殊的工作环境对光学元件的面形精度和表面质量均提出了很高的要求。在制造过程中，为了达到各项技术参数的要求，非球面光学元件必须经过反复检测，并将检测得到的面形精度信息反馈到加工系统中，以指导下一步加工工序的修正和补偿。为了使大口径光学元件检测平台的测量信息能够准确地指导加工，对大口径光学元件检测平台的精度提出了更高的要求。 本文以所在课题组自行研发设计的“大口径光学元件检测平台 ...
王詹帅
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Jellyfish blooms restructure plankton dynamics and trophic linkages in coastal waters
Functional Ecology, EarlyView.Read the free Plain Language Summary for this article on the Journal blog. Abstract Jellyfish blooms are increasing globally in frequency and intensity, introducing complex ecological interactions, yet the mechanisms by which they alter ecosystem structure remain poorly characterized due to a lack of sustained field observations.
Pengpeng Wang +4 more
wiley +1 more source
Study on A Novel Frequency Tunable Piezoelectric Vibration Energy Harvesting Device [PDF]
, 2015 随着传感器技术、嵌入式计算机技术、无线通信技术的快速发展，无线传感器网络（WSN）得到了广泛应用。传统电源已无法满足无线传感器网络应用的要求，因此俘获环境能量并将其转换为电能为无线传感器供电成为传统电源的一种替代方案。环境中的振动能凭借能量来源广泛、收集方便的特点而成为了很具吸引力的环境能量源。振动能量的回收方式主要有三种，即电磁式、静电式和压电式。其中压电俘能方式可以直接将施加的应变能转化成电能，适用于各种尺度，结构相对简单，无需额外的电源，而且易于集成 ...
李营泰
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Lessons from an eradication under multiple constraints of an island rat population of record density
Conservation Biology, EarlyView.Abstract Invasive rats threaten island biodiversity, disrupting ecosystems and endangering native species. Although rat eradication has succeeded on many islands, tropical islands present unique management challenges. Strict regulations and financial constraints on some tropical islands further limit proven eradication methods, complicating rodent ...
Tatiane Micheletti +7 more
wiley +1 more source
The design and development for X-ray absorption spectrum measurement system [PDF]
, 2016 组织光学是生物医学光子学的理论基础，组织光学特性参数的测量是其最重要也最艰难的任务，生物组织在不同生理状态下的成分会发生变化，健康与病变组织对光的吸收和散射不同，其光学参数也会随着光的波长而变化，测定组织在不同生理状态下的光学参数就可以对疾病进行诊断甚至前期诊断，进而及时进行治疗。制约组织光学发展的一个很重要的因素就是，所用光源（紫外到红外波段）对组织的穿透能力有限，无法实现较深部位的探测，而X射线具有良好的穿透能力，因此把组织光学推广到X射线范围不失为一种疾病诊断的有效途径 ...
胡波
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Conservation Biology, EarlyView.Abstract Consumer demand for ivory perpetuates the unsustainable and illegal killing of African elephants and other wildlife species. Interventions that aim to change consumer behavior are increasingly recognized as a crucial element of demand management. However, poor design and implementation have limited their effectiveness.
Molly R. C. Brown +2 more
wiley +1 more source
Research on Signal Pickup System for the Wireless Passive LC Resonant Pressure Sensor [PDF]
, 2016 在高温、潮湿等恶劣的环境中以及眼内压测量、疤痕治疗等应用场合，不便利用有线有源的传感器进行压力监测，LC谐振式无线压力传感器采用无线无源方式实现对压力信号的提取，拓展了压力传感器的应用范围。目前，LC谐振式无线压力传感器的信号拾取主要使用网络分析仪或阻抗分析仪，不仅成本高，而且携带不便，极大限制了非实验室场合的应用。本文针对LC谐振式无线MEMS压力传感器的信号拾取现状，从理论分析、系统仿真、硬件设计、软件设计和实验验证等方面展开研究，设计了基于阻抗实部测量法的信号拾取系统。 基于电感耦合理论 ...
蔡建法
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How much biotic nativeness matters across human demographic groups
Conservation Biology, EarlyView.Abstract Many central concepts of conservation biology—such as nativeness—are structured by ecological and social factors. However, the social consequences of using these concepts to make conservation decisions remain inadequately understood. Some researchers argue that nativeness, rather than acting as an objective proxy for important ecological ...
Harold N. Eyster, Rachelle K. Gould
wiley +1 more source
The Ultrasonic Liquid Level Instrument Based on STC89C52 Single Chip Microcomputer [PDF]
, 2016 在工业上，液位的测量被广泛应用于工业控制领域。对于某些比较恶劣的测量环境，不适宜由人直接测量液位的高低，这种情况下可采用水位仪来测量液位。超声波水位计是非接触型液位计，超声波水位计具有精度高、安装维护方便、适用范围广、价格便宜等优点而被广泛应用，提高了工业生产的智能化和安全性。 目前超声波水位仪的功能和价格，不同的厂家和不同的型号之间，相差较大。国内的产品相对比较便宜，但功能简单，精度不高。国外进口产品功能相对完善，精度较高，但价格不菲。对于一些中小型用户和企业来说，较难承受其价格，且维修不方便。因此 ...
庄鑫斌
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Comprehensive framework for assessing and optimizing existing research networks
Conservation Biology, EarlyView.Abstract Conservation, monitoring, and research networks, or collections of ecological research sites unified under a common mission of data collection or a research mission, are essential infrastructure for understanding large landscapes. However, most networks developed opportunistically over decades rather than through systematic design, creating ...
Alyson East +2 more
wiley +1 more source