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Numerical simulation of liquid desiccant evaporator driven by heat pump

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Journal of Central South University 2019年第8期26卷 2197-2213页

作者： niu Run-ping CHEN Xiao-yi WANG Zi-ye KUANG Da-qing School of Environment and Energy Engineering Beijing University of Civil Engineering and Architecture

The standard k-ε turbulence model and discrete phase model (DPM) were used to simulate the heat and mass transfer in a liquid-desiccant evaporator driven by a heat pump using FLUENT software, and the temperature field and velocity field in the device were obtained. The performance of the liquid-desiccant evaporator was studied as the concentration of the inlet solution varied between 21% and 30% and the pipe wall temperature between 30 and 50 ℃. Results show that the humidification rate and the humidification efficiency increased with the inlet air temperature, the solution flow rate, the solution temperature, and the pipe wall temperature. The humidification rate and humidification efficiency decreased with increasing moisture content in inlet air and the concentration of inlet solution. The humidification rate increased substantially but the humidification efficiency decreased as the inlet air flow rate increased. The error between the simulations and experimental results is acceptable, meaning that our model can provide a theoretical basis for optimizing the performance of a humidifying evaporator.

关键词： heat pump condensation heat discrete phase model (DPM) liquid desiccant evaporator numerical simulation

Applications of Inverted Pyramids Corroded by TMAH in PERL Silicon LED

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Semiconductor Photonics and Technology 2009年第4期15卷 229-234页

作者： GENG Bo-yun LI Xiao-yun niu ping-juan School of Information and Communication Engineering Tianjin Polytechnic University Tianjin 300160 CHN

In this paper, a novel and reliable structure of the side passivated emitter and the rear locallydiffused（PERL） silicon light emitting diodes （LEDs） is proposed. The inverted pyramids surface, the important interface in this structure, is given according to the experiment. The results show that the inverted pyramids surface has a low refection about 8%, in the anisotropic etching 70 ℃, 5% TMAH concentration, corrosion time of 90 min or 30 rain. Low refection means high light emitting rate. Most of the structure and manufacturing process can be compatible with planar CMOS technology, which makes the silicon LED greater potential for development in the future.

关键词： PERL structure silicon LED inverted pyramids TMAH

New High Efficiency LED Lighting Solution

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Semiconductor Photonics and Technology 2008年第3期14卷 213-216页

作者： DING Ke niu ping-juan FU Xian-song School of Information and Communication Engineering Tianjin Polytechnic University Tianjin 300160 CHN

As the quality of power LED improves and the cost of power LED reduces, semiconductor lighting will replace incandescent and fluorescent lighting gradually, causing another revolution on the lighting history. And its driving solution has been greatly accelerated. Based on the white power LED I-V characteristics and the application ambiance, proposed is a new LED lighting solution, suiting indoor and outdoor illumination. According to the test results, the design is optimized, and the electrical efficiency is 95% and the output current deviation is 13.0%.

关键词： LED lighting electrical efficiency output current deviation

Field synergy analysis of different flow patterns in falling-film dehumidification system with horizontal pipes

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Journal of Central South University 2020年第8期27卷 2353-2366页

作者： niu Run-ping KUANG Da-qing WANG Shi-zheng CHEN Xiao-yi Beijing Engineering Research Center of Sustainable Energy and Buildings Beijing University of Civil Engineering and ArchitectureBeijing 100044China

Effects of the flow pattern of intertubular liquid film on mass and heat transfer synergies in a falling-film dehumidification system with horizontal pipes are studied.A flow model of the dehumidifying solution between horizontal pipes is established using Fluent software,the rule of transitions of the flow pattern between pipes is studied,critical Reynolds numbers of flow pattern transitions are obtained,and the accuracy of the model is verified by *** mass transfer synergy angle and heat transfer synergy angle are respectively used as evaluation criteria for the mass transfer synergy and heat transfer synergy,and distribution laws of the synergy angles for droplet,droplet columnar and curtain flow patterns are *** results show that the mass transfer synergy angles corresponding to droplet,droplet columnar and curtain flow patterns all rise to a plateau with *** mean mass-transfer synergy angle is 98°for the droplet flow pattern,higher than 96.5°for the droplet columnar flow pattern and 95°for the curtain flow *** results show that the mass transfer synergy of the droplet flow pattern is better than that of the droplet columnar flow pattern and that of the curtain flow pattern.

关键词： film falling between horizontal pipes fluent software flow pattern of liquid film synergy angle mass and heat transfer

石羊河流域参考作物蒸发蒸腾量对气候变化的响应模拟及预测

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水利学报 2014年第3期45卷 286-295页

作者：牛纪苹粟晓玲西北农林科技大学水利与建筑工程学院陕西杨凌712100

模拟和预测气候变化对石羊河流域参考作物蒸发蒸腾量(ET0)时空分布的影响,为发展节水农业和科学利用水资源提供参考依据。根据石羊河流域及周边11个气象站点1951—2012年的逐日气象资料,使用PenmanMonteith公式计算现状ET0,利用大气环... 详细信息

模拟和预测气候变化对石羊河流域参考作物蒸发蒸腾量(ET0)时空分布的影响,为发展节水农业和科学利用水资源提供参考依据。根据石羊河流域及周边11个气象站点1951—2012年的逐日气象资料,使用PenmanMonteith公式计算现状ET0,利用大气环流模型HadCM3的输出和SDSM统计降尺度模型,预测A2、B2两种排放情景下未来石羊河流域2020s,2050s和2080s的ET0,使用反距离加权插值法(IDW)和Mann-Kendall检验分别研究ET0的空间分布特征和随时间的变化趋势。结果表明,石羊河流域多年平均ET0值为1 061mm,高值区位于东北地区,低值区位于西南地区,预计未来2020s、2050s和2080s,在HadCM3模式的A2情景下ET0将分别增加6%、14%和23%,B2情景下将分别增加7%、12%和17%,增幅较大的地区位于流域东南,2050s和2080s在B2情景下增幅低于A2情景。石羊河流域ET0在未来将持续增加,2050s之后增加趋势更为显著。

关键词：气候变化参考作物蒸发蒸腾量石羊河流域 SDSM

Time-resolved two-photon excitation fluorescence spectroscopy and microscopy using a high repetition rate streak camera

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Optoelectronics Letters 2007年第2期3卷 157-160页

作者： LIU Li-xin QU Ju-le LIN Zi-yang WANG Lei FU Zhe GUO Bao-ping niu Han-ben Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education Institute of Optoelectronics Shenzhen University Shenzhen 518060 China

We present a time-resolved two-photon excitation fluorescence spectroscopy and a simultaneous time- and spectrum- resolved multifocal multiphoton microscopy system that is based on a high repetition rate picosecond streak camera for providing time- and spectrum- resolved measurement and imaging in biomedicine. The performance of the system is tested and characterized by the fluorescence spectrum and lifetime analysis of several standard fluorescent dyes and their mixtures. Spectrum-resolved fluorescence lifetime images of fluorescence beads are obtained. Potential applications of the system include clinical diagnostics and cell biology etc.

关键词：时间分辨双光子激发荧光光谱显微镜高重复率皮秒超高速扫描照相机时间-光谱分辨同时测量生物医学

Controller Design of Intelligent Lighting Network

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Semiconductor Photonics and Technology 2009年第3期15卷 179-183页

作者： RONG Xue-juan niu ping-juan XU Xiu-zhi School of Information and Communication Engineering Tianjin Polytechnic University Tianjin 300160 CHN

Studied are the controller design and basic principles of intelligent lighting network. TI’s MSP430F123 is used as a main controller. By using the ZigBee modules(Xbee/Xbee-PRO) and the GSM module(SIM300C) for wireless communications, the lighting control is enabled to access wireless network. This system uses a mobile phone to achieve light on-off directly, which can accomplish wireless control of intelligent lighting in families.

关键词： intelligent lighting control Zigbee module GSM module lighting network controller

从“远夷”到“中华民族”共识的演变——《旅行杂志》中的云南边疆民族认知变迁

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云南民族大学学报（哲学社会科学版） 2024年第6期41卷 5-14页

作者：苍铭牛平中央民族大学历史文化学院北京100081

在以《旅行杂志》涉滇内容为切入点的探讨中,可以看到从“远夷”到“中华民族”共识的演变及内地对云南边疆民族认知变迁。近代中国,“华夷”观与“中华民族”说并存。民国以后,尤其抗战后“中华民族”说渐被认同,但“华夷”观仍有影响... 详细信息

在以《旅行杂志》涉滇内容为切入点的探讨中,可以看到从“远夷”到“中华民族”共识的演变及内地对云南边疆民族认知变迁。近代中国,“华夷”观与“中华民族”说并存。民国以后,尤其抗战后“中华民族”说渐被认同,但“华夷”观仍有影响。新中国建立后,“劳动者”“建设者”取代“华夷”,认同基准重构。《旅行杂志》不同时期对云南民族形象呈现不同,抗战前是“远夷”,抗战时是“典范”,建国后是“劳动者”“建设者”。形象差异源于接触程度和观念转变。中华民族形成过程中各民族共同开拓疆域、缔造国家、书写历史、创造文化、培育精神,《旅行杂志》从一个微观视角反映了其凝聚融合过程。

关键词：中华民族共同体意识五个共同《旅行杂志》 “华夷”观

Reinnervation of spinal cord anterior horn cells after median nerve repair using transposition with other nerves

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Neural Regeneration Research 2019年第4期14卷 699-705页

作者： Yu-Song Yuan Su-ping niu You-Lai Yu Pei-Xun Zhang Xiao-Feng Yin Na Han Ya-Jun Zhang Dian-Ying Zhang Hai-Lin Xu Yu-Hui Kou Bao-Guo Jiang Peking University People's Hospital The Affiliated Hospital of Xuzhou Medical University

Our previous studies have confirmed that during nerve transposition repair to injured peripheral nerves, the regenerated nerve fibers of motor neurons in the anterior horn of the spinal cord can effectively repair distal nerve and target muscle tissue and restore muscle motor function. To observe the effect of nerve regeneration and motor function recovery after several types of nerve transposition for median nerve defect(2 mm), 30 Sprague-Dawley rats were randomly divided into sham operation group, epineurial neurorrhaphy group, musculocutaneous nerve transposition group, medial pectoral nerve transposition group, and radial nerve muscular branch transposition group. Three months after nerve repair, the wrist flexion test was used to evaluate the recovery of wrist flexion after regeneration of median nerve in the affected limbs of rats. The number of myelinated nerve fibers, the thickness of myelin sheath, the diameter of axons and the cross-sectional area of axons in the proximal and distal segments of the repaired nerves were measured by osmic acid staining. The ratio of newly produced distal myelinated nerve fibers to the number of proximal myelinated nerve fibers was calculated. Wet weights of the flexor digitorum superficialis muscles were measured. Muscle fiber morphology was detected using hematoxylin-eosin staining. The cross-sectional area of muscle fibers was calculated to assess the recovery of muscles. Results showed that wrist flexion function was restored, and the nerve grew into the distal effector in all three nerve transposition groups and the epineurial neurorrhaphy group. There were differences in the number of myelinated nerve fibers in each group. The magnification of proximal to distal nerves was 1.80, 3.00, 2.50, and 3.12 in epineurial neurorrhaphy group, musculocutaneous nerve transposition group, medial pectoral nerve transposition group, and radial nerve muscular branch transposition group, respectively. Nevertheless, axon diameters of new

关键词： nerve regeneration transposition repair median nerve functional remodeling muscle atrophy surgical intervention peripheral nerve injury neural regeneration