Results 121 to 130 of about 91,243 (286)

Anaerobic respiration and its influence on the carbonate system in estuarine sediment [PDF]

open access: yes, 2015
海洋是大气CO2重要的汇。自工业革命以来,海洋吸收的人为CO2已导致表层海水中的自由氢离子浓度升高了26%,海水pH降低了0.1个单位,同时,水体溶解无机碳(DIC)和HCO3-浓度升高,CO32-浓度降低,海水碳酸盐系统对CO2的缓冲能力降低。碱度(TA)的高低是海水对pH变化起缓冲作用的重要因素,一般地说,TA越高,则海水碳酸盐系统的缓冲能力越强。 每年通过河口输入海洋的DIC大致相当于全球海洋吸收大气CO2量的20%,与同时入海的TA一起对海洋碳酸盐系统产生重要影响 ...
胡玲
core  

Acid‐Etched Co‐Vacancy‐Tunable CoFeP/N,P‐Codoped Carbon Nanocages for Highly Efficient Alkaline Water Electrolysis

open access: yesRare Metals, EarlyView.
ABSTRACT Efficient and durable bifunctional electrocatalysts are vital for scalable water electrolysis. Here, we realize cobalt‐vacancy (Covac) engineering in CoFeP supported on N,P‐codoped carbon nanocages (Co1‐vacFeP/NPC) through a simple route comprising a CoFe Prussian blue analog precursor, phosphidation–pyrolysis, tannic‐acid etching, and a ...
Yuan‐Liang Yuan   +6 more
wiley   +1 more source

脓肾合并应激性高血糖患者血糖变异性与肾功能及临床预后的相关性

open access: yesZhongguo shiyan zhenduanxue, 2016
目的探讨脓肾合并应激性高血糖患者血糖变异性与肾功能及临床预后的相关性。方法将我院收治的脓肾合并应激性高血糖患者根据24h血糖波动均值(GM)及血糖波动系数(GV)四分位间距从低到高分为Ⅰ组、Ⅱ组、Ⅲ组、Ⅳ组和A组、B组、C组、D组,记录不同分组APACHEⅡ评分、肾实质厚度、肾内动脉血流阻力指数、低血糖事件及脓毒血症发生率,分析GM与GV值以及二者与APACHEⅡ评分、肾功能及脓毒症发生的相关性。结果随着GM值、GV值的升高,患者APACHEⅡ评分、RI值以及脓毒症发生率均随之升高,肾实质厚度逐渐减小 ...
迟长亮   +6 more
doaj  

The Research about Chinese Language Teaching Based on Language Learning Behaviors [PDF]

open access: yes, 2016
近年来,课堂教学逐渐开始从传统的“以教师为中心”转向为“以学生为中心”的教学。汉语教学中,即使在同一个班级、环境、教师教学下学习,学习者的学习效率则不同。这差异的存在对学习者汉语学习水平产生了极大的影响。许多研究表明,学习者的学习还取决于学习者本人的学习行为,并强调学习者良好学习行为习惯培养的重要性。 本研究以语言学习行为为一个深入点来分析汉语教学情况,对学习者在汉语学习过程中表现出的学习行为进行探讨研究,并基于学习者的语言学习行为提出以学习者为主体的汉语教学建议 ...
ANGELY SETIAWAN(薛亦雯)
core  

An Ultrasmall Strontium‐Loaded Polydopamine Nanoformulation for Near‐Infrared‐Enhanced Periodontitis Therapy via Photodynamic Gas‐Promoted Antibacterial and Bone Repair

open access: yesRare Metals, EarlyView.
ABSTRACT Periodontitis is a chronic infectious oral disease triggered by periodontopathogenic bacteria, resulting in the progressive inflammation and destruction of the tissues surrounding teeth. To achieve reprogramming of the infectious microenvironment for periodontitis therapy, a nanoformulation was proposed by loading polydopamine (PDA) with ...
Hao Liang   +14 more
wiley   +1 more source

EB病毒相关性疾病病理学研究的进展

open access: yesZhongshan Daxue xuebao. Yixue kexue ban, 2005
报告作者及其同事在鼻咽癌高发的广州地区所做EB 病毒相关性疾病病理学研究的进展。内容 包括: ①EB 病毒病理生物学; ②EB 病毒相关性疾病病理学; ③检测组织中的EB 病毒; ④EB 病毒血清学。 重点是EB 病毒相关性疾病的病理学以及评估各种检测EB 病毒相关性疾病患者组织和血清中EB 病毒的方 法。
宗永生   +4 more
doaj  

Study on the relationship between red meat, dietary Neu5Gc intake and anti-Neu5Gc antibody [PDF]

open access: yes, 2015
唾液酸类化合物是以九碳糖神经氨酸(5-amino-3,5-dideoxy-D-glycero-D-galactononulsonicacid)为基本结构的一族衍生物的总称。目前,已分离和鉴定的有50余种,包括N-乙酰基神经氨酸(N-acetylneuraminicacid,Neu5Ac)、N-羟乙酰基神经氨酸(N-glycoulylneuraminicacid,Neu5Gc)和2-酮基-3-脱氧九酮糖酸(2-keto-3-deoxy-nonulosonicacid,KDN)三种核心单体 ...
范杏丹
core  

Optimizing the Surface Coordination of Pd‐Cu Nanoalloy Through Chemical Ordering to Enhance Hydrogenation Selectivity

open access: yesRare Metals, EarlyView.
ABSTRACT Precise control of chemical ordering in bimetallic nanocatalysts offers a route to decouple activity and selectivity in acetylene hydrogenation, but direct atomic‐scale evidence linking surface order to catalytic performance is scarce. Here, we tune Pd‐Cu nanoalloys from chemically disordered to highly ordered states by composition control and
Fan Xue   +5 more
wiley   +1 more source

多级电涌保护器对负载有效性试验分析

open access: yesDianci bileiqi, 2014
针对多级电涌保护器(SPD)安装在电源线路时可能对负载电压起到抑制作用,而导致SPD达不到预期的有效性保护的问题,通过组合波发生器(1.2/50μs、8/20μs)模拟雷电流,对负载分别为阻性、容性、感性时,特性阻抗值相同、长度不同的RVVP电缆做冲击试验,研究负载与RVVP电缆特性阻抗匹配关系及波电缆中的折反射现象,分析电缆的长度与不同特性负载的关系,得出当负载为阻性时,多级电涌保护器的有效防护距离与电阻值呈负相关;当负载为容性时,多级电涌保护器的有效防护距离与电容值呈先负相关后正相关;当负载为感性时,
周中山   +4 more
doaj  

我国城市大气PM2.5与O3浓度相关性的时空特征分析

open access: yesChinese Science Bulletin, 2021
Yanting Qiu   +13 more
semanticscholar   +1 more source

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