检索结果-南通市图书馆

Second pregnancy of trisomy 21 in a mother with mosaicism

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2007年第14期120卷 1295-1296页

作者： CUI ying-xia HAO Li-jun WANG Yun-hua XIA Xin-yi SHI yi-chao lu Hong-yong YAO Bing HUANG Yu-feng Department of Reproduction and Genetics Jinling Hospital Clinical School of Medical College Nanjing University Nanjing 210002 China

In the case of a previous offspring with trisomy 21, recurrence risk for Down syndrome is about 1%. It may be due to chance, but the possibility of germline mosaicism for trisomy 21 in one of the parents has important... 详细信息

关键词： trisomy 21 mosaicism microsatellite markers

Numerical Study of Flow and Heat Transfer Characteristics of Shell-and-Tube Molten Salt Electric Heater with Circularly Perforated Baffles

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2025年第1期34卷 24-33页

作者： LIN Yongjie ZHANG Cancan WU Yuting ZHANG yi lu Yuanwei Key Laboratory of Heat Transfer and Energy Conversion National User-Side Energy Storage Innovation Research and Development CenterBeijing University of Technology

Numerical simulations of the flow and heat transfer characteristics of four shell-and-tube molten salt electric heaters with different perforation rates was ***-and-tube electric heaters have the same geometry and tube arrangement,and all of them use single segmental baffles,but there exist four different baffle openings（φ）,i.e.,0%,2.52%,4.06%,and 6.31%.The results indicated that the reasonable baffle opening could significantly reduce the shell-side pressure drop,effectively decreasing the shell-side flow dead zone *** can eliminate the local high-temperature phenomenon on the surface of electric heating tubes,but the heat transfer coefficient is slightly *** perforated schemes significantly reduce shell-side pressure drop compared to the baseline solution without open *** particular,the φ=6.31% scheme exhibits the optimal performance among all the schemes,with a maximum reduction of up to 50.50% in shell-side pressure drop relative to the unopened holes *** heat transfer coefficient is the highest for φ=0%,exhibiting a range of5.26% to 5.73%,5.14% to 5.99%,and 7.31% to 8.54% higher than φ=2.52%,4.06%,and 6.31%,respectively,within the calculated *** composite index h/（Δp）1/3was higher for all open-hole solutions than that for the unopened-hole *** best overall performance was for φ=6.31%,which improved the composite index by15.29% to 17.18% over the unopened-hole solution.

关键词： molten salt electric heater perforated baffles heat transfer

Identifying the dynamic behaviors in complete reconstruction of Co-based complex precatalysts during electrocatalytic oxygen evolution

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2025年第1期100卷 226-233页

作者： Jingfang Zhang Danyang Wu Linke Cai Youluan lu Fanpeng Cheng Lijuan Shi Qun yi Yao Liu yi Huang Key Laboratory of Green Chemical Engineering Process of Ministry of Education Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of Education Hubei Key Laboratory of Novel Reactor and Green Chemical Technology School of Chemical Engineering & Pharmacy Wuhan Institute of Technology Key Laboratory of Pesticide & Chemical Biology of Ministry of Education Engineering Research Center of Photoenergy Utilization for Pollution Control and Carbon Reduction of Ministry of Education College of Chemistry Central China Normal University College of Materials Science and Engineering Fuzhou University

Transition metal-based nanomaterials have emerged as promising electrocatalysts for oxygen evolution reaction（OER）. Considerable research efforts have shown that self-reconstruction occurs on these nanomaterials under operating conditions of OER process. However, most of them undergo incomplete reconstruction with limited thickness of reconstruction layer, leading to low component utilization and arduous exploration of real catalytic mechanism. Herein, we identify the dynamic behaviors in complete reconstruction of Co-based complexes during OER. The hollow phytic acid（PA） cross-linked CoFe-based complex nanoboxes with porous nanowalls are designed because of their good electrolyte penetration and mass transport ability, in favor of the fast and complete reconstruction. A series of experiment characterizations demonstrate that the reconstruction process includes the fast substitution of PA by OH-to form Co（Fe）(OH)xand subsequent potential-driven oxidation to Co（Fe）OOH. The obtained CoFeOOH delivers a low overpotential of 290 mV at a current density of 10 mA cm-2and a long-term *** experiment results together with theory calculations reveal that the Fe incorporation can result in the electron rearrangement of reconstructed CoFeOOH and optimization of their electronic structure,accounting for the enhanced OER activity. The work provides new insights into complete reconstruction of metal-based complexes during OER and offers guidelines for rational design of high-performance electrocatalysts.

关键词： Oxygen evolution reaction

PMD and CD Characterization of Chirped FBG Using Microwave Photonic Technique

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

光学学报 2003年第S1期23卷 133-134页

作者： Xiaoke yi, chao lu, Fang Wei, yixin Wang, Wende Zhong Network Technology Research Center (S2-B3c-23), Nanyang Technological University. Singapore 639798 Institute for Communications Research, Singapore Network Technology Research Center S2-B3c-23 Nanyang Technological University Singapore 639798 Institute for Communications Research Singapore

We present and demonstrate experimentally a new method for measuring the polarization-mode-dispersion(PMD) of a Chirped Fiber Bragg Grating. The technique has also been applied to accurate chromatic dispersion evaluat... 详细信息

关键词： PMD and CD Characterization of Chirped FBG Using Microwave Photonic Technique on in CFBG of CD

基于神经网络模拟的祁连山冰碛垄及其时空变化

在线全文

学校读者我要写书评

暂无评论

冰川冻土 2011年第3期33卷 564-572页

作者：梁越华易朝路金耀中国科学院青藏高原研究所青藏高原环境变化与地表过程重点实验室北京100085 中国科学院研究生院北京100049

采用DGPS测量技术对祁连山东段冷龙岭南坡老龙湾沟和北坡的宁缠河谷、中段的摆浪河谷、西段大雪山老虎沟的小冰期、新冰期和末次冰期的冰碛垄形态分别进行了实地测量和研究.以MAT-LAB软件为平台,应用人工神经网络方法模拟恢复了各个冰... 详细信息

采用DGPS测量技术对祁连山东段冷龙岭南坡老龙湾沟和北坡的宁缠河谷、中段的摆浪河谷、西段大雪山老虎沟的小冰期、新冰期和末次冰期的冰碛垄形态分别进行了实地测量和研究.以MAT-LAB软件为平台,应用人工神经网络方法模拟恢复了各个冰期的冰碛垄形态.结果表明:利用MAT-LAB人工神经网络方法,在保证模拟高程和实测高程之差不超过1m的情况下,可以提高工作效率;祁连山地区小冰期以来冰川退缩了0.56～0.73km,新冰期退缩的长度为小冰期的3.3～3.8倍,末次冰期冰川发育的山麓冰川遵循另外的形态变化规律;在空间上,祁连山地区的冰碛地貌发育受山谷形态影响,同一地区的冰碛垄的曲率遵循一定的规律.冷龙岭南北坡可能由于太阳辐射差异的影响,北坡各个期次的冰碛垄发育规模均小于南坡.

关键词：祁连山冰碛垄地貌模拟冰期

From waste to wealth:Coal tar residue derived carbon materials as low-cost anodes for potassium-ion batteries

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 464-475页

作者： Zhonghua lu Jun Shen Xin Zhang Lingcong chao Liang Chen Ding Zhang Tao Wei Shoudong Xu College of Chemical Engineering and Technology Taiyuan University of TechnologyTaiyuan 030024China College of Chemistry Taiyuan University of TechnologyTaiyuan 030024China School of Chemical Engineering and Pharmacy Wuhan Institute of TechnologyWuhan 430205China School of Energy and Power Jiangsu University of Science and TechnologyZhenjiang 212003China

Carbon materials are widely recognized as highly promising electrode materials for various energy storage system *** tar residues(CTR),as a type of carbon-rich solid waste with high value-added utilization,are crucially important for the development of a more sustainable *** this study,we employed a straightforward direct carbonization method within the temperature range of 700-1000℃to convert the worthless solid waste CTR into economically valuable carbon materials as anodes for potassium-ion batteries(PIBs).The effect of carbonization temperature on the microstructure and the potassium ions storage properties of CTR-derived carbons(CTRCs)were systematically explored by structural and morphological characterization,alongside electrochemical performances *** on the co-regulation between the turbine layers,crystal structure,pore structure,functional groups,and electrical conductivity of CTR-derived carbon carbonized at 900℃(CTRC-900H),the electrode material with high reversible capacity of 265.6m Ah·g^(-1)at 50 m A·g^(-1),a desirable cycling stability with 93.8%capacity retention even after 100 cycles,and the remarkable rate performance for PIBs were ***,cyclic voltammetry(CV)at different scan rates and galvanostatic intermittent titration technique(GITT)have been employed to explore the potassium ions storage mechanism and electrochemical kinetics of *** indicate that the electrode behavior is predominantly governed by surface-induced capacitive processes,particularly under high current densities,with the potassium storage mechanism characterized by an“adsorption-weak intercalation”*** work highlights the potential of CTR-based carbon as a promising electrode material category suitable for high-performance PIBs electrodes,while also provides valuable insights into the new avenues for the high value-added utilization of CTR.

关键词： coal tar residue carbon materials anode potassium-ion batteries high value-added

在线全文

学校读者我要写书评

暂无评论

珠穆朗玛峰绒布河谷冰碛地貌测量与演化研究

冰川冻土 2010年第2期32卷 316-324页

作者：胡恩易朝路李艳军中国科学院青藏高原研究所青藏高原环境变化与地表过程重点实验室北京100085

采用后差分GPS方法对珠穆朗玛峰北坡绒布河谷中时期的冰碛地貌进行实地测量与研究,结合该河谷数值年代,得到时间序列上关于各期次冰碛地貌终碛垄的平面面积、表面面积、体积等参数:基龙寺终碛平面面积、表面面积以及体积分别为1.53×10... 详细信息

采用后差分GPS方法对珠穆朗玛峰北坡绒布河谷中时期的冰碛地貌进行实地测量与研究,结合该河谷数值年代,得到时间序列上关于各期次冰碛地貌终碛垄的平面面积、表面面积、体积等参数:基龙寺终碛平面面积、表面面积以及体积分别为1.53×106m2、1.90×106m2和1.98×108m3;绒布寺终碛为1.03×106m2、1.24×106m2和0.82×108m3;绒布德新冰期终碛为1.72×106m2、2.0×106m2和1.98×108m3;小冰期终碛及现代表碛为2.43×106m2、2.60×106m2和1.69×108m3.对比分析认为:河谷地形差异是控制绒布河谷冰碛地貌表面形态的主要因素,冰碛地貌形成过程中冰川退缩方式以及形成以后所遭受的流水切割、搬运等外力作用是影响冰碛垄规模大小差异的基本原因.受局地小气候差异影响,同期次侧碛表现出形态特征的不对称性:新冰期东坡侧碛坡度值大于西坡侧碛,前者为30.7°～46°,后者为30.7°～37.9°,另外在东坡侧碛发育有冰碛土柱,西坡侧碛未见分布.

关键词：珠穆朗玛峰绒布河谷冰碛地貌差分GPS 控制因素

在线全文

学校读者我要写书评

暂无评论

珠穆朗玛峰绒布河谷微地貌研究

冰川冻土 2010年第4期32卷 696-705页

作者：李艳军易朝路胡恩中国科学院青藏高原环境变化与地表过程重点实验室青藏高原研究所北京100085

珠穆朗玛峰绒布河谷上游东侧新冰期的侧碛垄坡面上发育有高度2.52～17.98m的土柱,分布范围在0.2km2左右.根据激光测距仪和DGPS测量、DEM和GIS空间分析,得到土柱及其坡面的形态参数;结合地貌特征,将这种局部地区特殊微地貌体发育过程划... 详细信息

珠穆朗玛峰绒布河谷上游东侧新冰期的侧碛垄坡面上发育有高度2.52～17.98m的土柱,分布范围在0.2km2左右.根据激光测距仪和DGPS测量、DEM和GIS空间分析,得到土柱及其坡面的形态参数;结合地貌特征,将这种局部地区特殊微地貌体发育过程划分为孕育期、成熟期及消亡期三个发育阶段.初步认为,冰碛土柱的发育与侧碛垄坡度、日温差、降水的季节分布及冰川风、山谷风有关.冰碛土柱是冻融作用、流水侵蚀作用、重力崩塌及风蚀等因素共同作用的产物,局地地形和气候因素对冰碛土柱的演化作用明显.

关键词：绒布河谷冰碛土柱形成条件动力作用

在线全文

学校读者我要写书评

暂无评论

冰缘风沙地貌与沉积研究进展

冰川冻土 2006年第2期28卷 199-210页

作者：李馨李孝泽易朝路朱志勇中国科学院寒区旱区环境与工程研究所甘肃兰州730000 中国科学院青藏高原研究所北京100085

冰缘风沙地貌与沉积是在冰缘寒冷干旱气候环境中,伴有冰川或冻融作用影响,主要由风沙作用形成的荒漠地貌.现代冰缘荒漠主要分布于南、北半球的高纬度地区及中低纬度的高海拔地区,部分温带沙漠也有古冰缘荒漠沉积分布.冰缘沙丘的规模一... 详细信息

冰缘风沙地貌与沉积是在冰缘寒冷干旱气候环境中,伴有冰川或冻融作用影响,主要由风沙作用形成的荒漠地貌.现代冰缘荒漠主要分布于南、北半球的高纬度地区及中低纬度的高海拔地区,部分温带沙漠也有古冰缘荒漠沉积分布.冰缘沙丘的规模一般较小,沙丘沉积富含腐殖质及冰粒,并兼具冻融和积雪层理构造等,砂的化学及物理成熟度较低.冰缘风沙沉积往往与邻近的其它沉积相伴生,如黄土、冰川、湖泊、海洋甚至火山碎屑,因而可参与区域气候、环境,尤其是古环流的恢复与重建,也可为研究温带荒漠在冰期时的演化提供参考.目前在冰缘沙漠研究中已经取得了一些可喜的成绩,但在确定冰缘荒漠的原因过程方面还没有形成系统的理论,更多工作有待进行.青藏高原腹地的普若岗日冰缘沙丘与戈壁,是我国典型的冰缘荒漠地貌与沉积,研究其地貌与环境过程,对丰富我国沙漠学研究内容和了解晚第四纪高原腹地气候、环境变化具有重要意义.

关键词：冰缘沙漠环境风沙地貌与沉积研究进展