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血液高RDW和高N-MID OC/β-CTX比值在老年女性椎体骨折中的诊断价值 被引量:1
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作者 邹明 池继敏 +4 位作者 唐敏 桑阳 陈永丽 邓顺 岳建彪 《西部医学》 2024年第2期268-273,共6页
目的 探讨血液红细胞分布宽度(RDW)及骨钙素N段中分子片段(N-MID OC)/Ⅰ型胶原羧基端肽β特殊序列(β-CTX)比值联合检测对老年女性骨质疏松椎体骨折(OPVF)的诊断价值。方法 纳入2021年1月—2021年12月我院≥60岁女性骨质疏松住院患者786... 目的 探讨血液红细胞分布宽度(RDW)及骨钙素N段中分子片段(N-MID OC)/Ⅰ型胶原羧基端肽β特殊序列(β-CTX)比值联合检测对老年女性骨质疏松椎体骨折(OPVF)的诊断价值。方法 纳入2021年1月—2021年12月我院≥60岁女性骨质疏松住院患者786例,分为无骨折组(A组,378例)和OPVF组(B组,388例)。N-MID OC、β-CTX、NMID-OC/β-CTX比值、红细胞计数(RBC)、红细胞压积(HCT)、血红蛋白(Hb)、红细胞平均体积(MCV)、平均血红蛋白浓度(MCHC)、平均血红蛋白量(MCH)、红细胞分布宽度(RDW-CV)、钙(Ca)、磷(P)及镁(Mg)。结果 与A组相比,B组Ca、P、Hb、HCT、MCV、MCH、MCHC含量降低,RDW-CV、N-MID OC/β-CTX含量增加,差异有统计学意义(均P<0.05)。OPVF与β-CTX、Ca、P呈负相关,与RDW-CV、N-MID OC/β-CTX呈正相关(均P<0.05)。骨折患者RDW与N-MID OC、β-CTX、Ca、P、Mg呈负相关(均P<0.05)。RDW、N-MID-OC/β-CTX为OPVF的风险因素(均P<0.05),OR分别为1.38、1.005。二者含量越高,椎体骨折风险越高,最高层是最低层的约3倍和2倍,OR为2.818,1.734。二者联合检测可提高对OPVF的诊断性能,其AUC敏感性、特异性、阳性预示值、阴性预示值分别为0.64、42.78%、82.01%、70.9%、58.3%。结论 血液高RDW和高N-MID OC/β-CTX比值与老年女性骨质疏松性椎体骨折明显相关,是其危险因素,可用于辅助诊断及预测其发生。 展开更多
关键词 红细胞分布宽度 骨钙素n段中分子片段/Ⅰ型胶原羧基端肽β特殊序列 老年女性 骨质疏松 椎体骨折
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Hb Lepore-Boston-Washington型杂合缺失的诊断分析及文献复习
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作者 唐斌 王继成 +9 位作者 秦丹卿 姚翠泽 梁杰 梁凯玲 陈柯艺 詹文丽 梁丽华 柴慧颖 郭浩 杜丽 《中国产前诊断杂志(电子版)》 2024年第2期25-30,共6页
目的报道国内罕见的Hb Lepore-Boston-Washington杂合缺失病例并探讨毛细管电泳法和高效液相色谱法对其筛查时需要注意的问题,结合文献探讨该病的血液学特点和临床表型,以期为临床诊疗提供参考。方法采集外周血进行血液学分析。采用全... 目的报道国内罕见的Hb Lepore-Boston-Washington杂合缺失病例并探讨毛细管电泳法和高效液相色谱法对其筛查时需要注意的问题,结合文献探讨该病的血液学特点和临床表型,以期为临床诊疗提供参考。方法采集外周血进行血液学分析。采用全自动毛细管电泳系统检测血红蛋白组分。应用PCR-流式荧光杂交法对常见的α-珠蛋白基因3种缺失、3种突变、β-珠蛋白基因17种突变进行检测。应用DNA测序分析HBB突变类型。结果该患者血液学表型为HGB:136 g/L、RBC:5.8×10^(12)/L、MCV:71.4 fL、MCH:23.4 pg。毛细管电泳结果显示:Hb A:84.7%;Hb A_(2):2.3%;Hb F:2.9%;Hb D:10.1%。DNA测序结果显示为Hb Lepore-Boston-Washington型杂合缺失。结论该病例为β珠蛋白基因第二内含子基因序列与δ珠蛋白基因序列发生了融合,不等交换重组位点发生在δ-基因87位与β-基因IVS-II nt 8之间。该类型突变在中国人群中属于罕见型,确诊需要依赖基因诊断。在地中海贫血(地贫)高危人群中,尤其是当其配偶疑似为β-地贫携带者时,要警惕此类地贫基因突变的筛查和检测,避免重型β-地贫患儿的出生。 展开更多
关键词 Hb Lepore-Boston-washington δ珠蛋白 Β珠蛋白 基因重组 罕见型
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时效时间对Ni-W-Al-Ti高密度合金组织与性能的影响
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作者 高达 张丽辉 +4 位作者 侯振昌 聂志华 齐闯 张楚博 张强 《机械工程材料》 CAS CSCD 北大核心 2024年第6期81-87,共7页
基于面心立方结构及细小弥散相强化原理,设计了一种新型Ni-W-Al-Ti高密度合金(密度为10.8 g·cm^(-3)),将其在750℃下进行不同时间(0,8,16,24,32 h)的时效处理,研究了时效时间对合金显微组织和拉伸性能的影响。结果表明:时效处理后,... 基于面心立方结构及细小弥散相强化原理,设计了一种新型Ni-W-Al-Ti高密度合金(密度为10.8 g·cm^(-3)),将其在750℃下进行不同时间(0,8,16,24,32 h)的时效处理,研究了时效时间对合金显微组织和拉伸性能的影响。结果表明:时效处理后,Ni-W-Al-Ti高密度合金中析出了长程有序的D1_(a)型Ni_(4)W和L1_(2)型Ni_(3)Al强化相,随着时效时间延长,Ni_(4)W相尺寸增大,形状由球状变为椭球状,Ni_(3)Al相数量增多;随着时效时间延长,合金的屈服强度先增加后趋于稳定,抗拉强度无明显变化,断后伸长率减小;当时效时间为24 h时,合金的屈服强度最大,为740 MPa,抗拉强度和断后伸长率适中,分别为886 MPa,9%,综合拉伸性能较佳。 展开更多
关键词 高密度合金 时效处理 ni4w ni3Al相 拉伸性能
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Grain yield and N uptake of maize in response to increased plant density under reduced water and nitrogen supply conditions 被引量:1
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作者 Jingui Wei Qiang Chai +5 位作者 Wen Yin Hong Fan Yao Guo Falong Hu Zhilong Fan QimingWang 《Journal of Integrative Agriculture》 SCIE CSCD 2024年第1期122-140,共19页
The development of modern agriculture requires the reduction of water and chemical N fertilizer inputs.Increasing the planting density can maintain higher yields,but also consumes more of these restrictive resources.H... The development of modern agriculture requires the reduction of water and chemical N fertilizer inputs.Increasing the planting density can maintain higher yields,but also consumes more of these restrictive resources.However,whether an increased maize density can compensate for the negative effects of reduced water and N supply on grain yield and N uptake in the arid irrigated areas remains unknown.This study is part of a long-term positioning trial that started in 2016.A split-split plot field experiment of maize was implemented in the arid irrigated area of northwestern China in 2020 to 2021.The treatments included two irrigation levels:local conventional irrigation reduced by 20%(W1,3,240 m^(3)ha^(-1))and local conventional irrigation(W2,4,050 m^(3)ha^(-1));two N application rates:local conventional N reduced by 25%(N1,270 kg ha^(-1))and local conventional N(360 kg ha^(-1));and three planting densities:local conventional density(D1,75,000 plants ha^(-1)),density increased by 30%(D2,97,500 plants ha-1),and density increased by 60%(D3,120,000 plants ha^(-1)).Our results showed that the grain yield and aboveground N accumulation of maize were lower under the reduced water and N inputs,but increasing the maize density by 30% can compensate for the reductions of grain yield and aboveground N accumulation caused by the reduced water and N supply.When water was reduced while the N application rate remained unchanged,increasing the planting density by 30% enhanced grain yield by 13.9% and aboveground N accumulation by 15.3%.Under reduced water and N inputs,increasing the maize density by 30% enhanced N uptake efficiency and N partial factor productivity,and it also compensated for the N harvest index and N metabolic related enzyme activities.Compared with W2N2D1,the N uptake efficiency and N partial factor productivity increased by 28.6 and 17.6%under W1N1D2.W1N2D2 had 8.4% higher N uptake efficiency and 13.9% higher N partial factor productivity than W2N2D1.W1N2D2 improved urease activity and nitrate reductase activity by 5.4% at the R2(blister)stage and 19.6% at the V6(6th leaf)stage,and increased net income and the benefit:cost ratio by 22.1 and 16.7%,respectively.W1N1D2 and W1N2D2 reduced the nitrate nitrogen and ammoniacal nitrogen contents at the R6 stage in the 40-100 cm soil layer,compared with W2N2D1.In summary,increasing the planting density by 30% can compensate for the loss of grain yield and aboveground N accumulation under reduced water and N inputs.Meanwhile,increasing the maize density by 30% improved grain yield and aboveground N accumulation when water was reduced by 20% while the N application rate remained constant in arid irrigation areas. 展开更多
关键词 water and n reduction plant density MAIZE grain yield n uptake compensation effect
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旋转锻造加工高比重W-Ni-Fe合金的退火工艺研究
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作者 李天瑞 冯宏伟 +4 位作者 黄滢秋 刘晓彬 黄伟 周朝红 陈子明 《热加工工艺》 北大核心 2024年第6期62-66,71,共6页
使用粉末冶金工艺制备Ni/Fe为7∶3的W-Ni-Fe高比重钨合金,在使用旋转锻造方法进行形变强化后进行热处理。结果表明,锻造态W-Ni-Fe合金经过一定温度的锻后退火,强度有所提高,而塑性下降。样品的强度在一定的退火温度和保温时间范围内能... 使用粉末冶金工艺制备Ni/Fe为7∶3的W-Ni-Fe高比重钨合金,在使用旋转锻造方法进行形变强化后进行热处理。结果表明,锻造态W-Ni-Fe合金经过一定温度的锻后退火,强度有所提高,而塑性下降。样品的强度在一定的退火温度和保温时间范围内能得到提升,更高温度和更高时间的保温会使样品强度下降。不同钨含量的W-Ni-Fe合金,强度提升最大的退火温度和时间条件不同。SEM图像显示,退火前样品钨颗粒因旋转锻造变形呈现长条状织构,退火后钨颗粒的形状无明显变化。这些现象说明,锻造变形的合金样品经过锻后退火发生应变时效现象,使强度得到提升。研究明确了不同钨含量的W-Ni-Fe合金最佳的锻后退火工艺参数。 展开更多
关键词 高比重钨合金 w-nI-FE合金 旋转锻造 退火
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18Cr2Ni4W钢的热变形行为及热加工图
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作者 蔡述巧 王勇帆 +3 位作者 陈克鑫 纪宏志 谷大鹏 刘鑫刚 《材料热处理学报》 CAS CSCD 北大核心 2024年第7期201-211,共11页
在变形温度为850~1200℃,应变速率为0.005~0.5 s^(-1)及真应变为0.8的条件下,采用Gleeble-3800型热模拟试验机对18Cr2Ni4W钢进行热压缩试验,分析其真实应力-应变曲线,基于双曲正弦函数,建立了18Cr2Ni4W钢的热变形本构方程;采用动态材料... 在变形温度为850~1200℃,应变速率为0.005~0.5 s^(-1)及真应变为0.8的条件下,采用Gleeble-3800型热模拟试验机对18Cr2Ni4W钢进行热压缩试验,分析其真实应力-应变曲线,基于双曲正弦函数,建立了18Cr2Ni4W钢的热变形本构方程;采用动态材料模型(DMM),建立了18Cr2Ni4W钢在真应变为0.8时的热加工图。结果表明:18Cr2Ni4W钢在热加工过程中发生了动态再结晶,流变应力随着变形温度的升高而降低,随着应变速率的增加而增加;峰值应力随应变速率的降低和变形温度的升高而降低。失稳区主要集中分布于变形温度为860~950℃、应变速率为0.03~0.5 s^(-1)的范围内,其显微组织为沿变形方向拉长的带状组织,并存在局部流动性,对应的功率耗散η值较低,小于0.2;安全区的显微组织是典型动态再结晶组织,功率耗散η值较高,在0.28~0.49之间。在真应变为0.8时,18Cr2Ni4W钢最佳的热加工工艺为:变形温度为975~1050℃、应变速率为0.01~0.14 s^(-1)以及变形温度为1050~1200℃、应变速率为0.01~0.5 s^(-1)。 展开更多
关键词 18Cr2ni4w 热变形行为 本构方程 热变形组织 热加工图
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(Cr_(0.87),V_(0.13))_(2)(C,N)含量对WC-10Co硬质合金微观组织及力学性能的影响
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作者 李祥坤 王璐 叶金文 《工具技术》 北大核心 2024年第6期50-55,共6页
通过添加一种新型抑制剂(Cr_(0.87),V_(0.13))_(2)(C,N)制备出室温和高温下均性能优异的WC-10Co硬质合金,并研究(Cr_(0.87),V_(0.13))_(2)(C,N)含量对WC-10Co硬质合金微观组织、室温力学性能和高温硬度的影响。结果表明,添加(Cr_(0.87),... 通过添加一种新型抑制剂(Cr_(0.87),V_(0.13))_(2)(C,N)制备出室温和高温下均性能优异的WC-10Co硬质合金,并研究(Cr_(0.87),V_(0.13))_(2)(C,N)含量对WC-10Co硬质合金微观组织、室温力学性能和高温硬度的影响。结果表明,添加(Cr_(0.87),V_(0.13))_(2)(C,N)具有良好的细化WC晶粒的效果,随着(Cr_(0.87),V_(0.13))_(2)(C,N)含量增加,WC晶粒不断细化,硬度逐渐增加,断裂韧性降低,抗弯强度(TRS)先升高后降低,当(Cr_(0.87),V_(0.13))_(2)(C,N)的添加量为0.6wt.%时,抗弯强度最高为3840.5MPa。抑制剂(Cr_(0.87),V_(0.13))_(2)(C,N)的加入对高温硬度具有积极影响,随着(Cr_(0.87),V_(0.13))_(2)(C,N)含量增加,高温硬度逐渐增加;当(Cr_(0.87),V_(0.13))_(2)(C,N)含量不变时,随着温度升高,硬度逐渐降低。 展开更多
关键词 (Cr_(0.87) V_(0.13))_(2)(C n) 微观组织 室温力学性能 高温硬度
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元素添加对两步烧结W-6Ni-4Co合金组织和力学性能的影响
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作者 户晓南 董洪峰 李培友 《稀有金属与硬质合金》 CAS CSCD 北大核心 2024年第1期17-23,37,共8页
采用粉末冶金技术制备W-6Ni-4Co-2X(X=Nb、Ta、Hf、Mo、Ti)合金,研究添加Nb、Ta、Hf、Mo和Ti元素对W-6Ni-4Co合金组织和力学性能的影响。结果表明:W-6Ni-4Co-2X合金的显微组织主要由基体相(W相)和黏结相组成,且黏结相的种类和含量与烧... 采用粉末冶金技术制备W-6Ni-4Co-2X(X=Nb、Ta、Hf、Mo、Ti)合金,研究添加Nb、Ta、Hf、Mo和Ti元素对W-6Ni-4Co合金组织和力学性能的影响。结果表明:W-6Ni-4Co-2X合金的显微组织主要由基体相(W相)和黏结相组成,且黏结相的种类和含量与烧结过程W相在黏结相(Ni,Co)中的溶解析出有关。W-6Ni-4Co-2Ta、W-6Ni-4Co-2Hf合金组织W晶粒呈不规则多边形,W-6Ni-4Co-2Nb、W-6Ni-4Co-2Ti合金组织W晶粒呈椭球形,并分散分布在黏结相中。W-6Ni-4Co-2Ta合金组织均匀、晶粒细小、W/黏结相界面结合良好,使其硬度、抗弯强度和屈服强度较高。W-6Ni-4Co-2Mo合金组织W晶粒呈网状排列,连续W骨架结构与延性黏结相协同降低了合金的应变硬化程度,使其具有较好的抗应变硬化性能。因此,向W-6Ni-4Co合金中添加合适的过渡金属元素是提高其力学性能的一种有效途径。 展开更多
关键词 w-ni-Co合金 金属元素添加 两步烧结 微观组织 力学性能
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用于金刚石摩擦化学抛光的Ni-W合金盘制备
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作者 牛昊 金洙吉 +1 位作者 沈煜 杨辉鹏 《金刚石与磨料磨具工程》 CAS 北大核心 2024年第1期39-49,共11页
为探究镀液成分、工艺条件等因素对Ni-W合金镀层的影响,制备出低内应力、高硬度的Ni-W合金盘,用于金刚石的摩擦化学抛光。采用单一性实验分别探究络合剂浓度、溶液pH、糖精钠浓度对镀层内应力、钨含量、硬度以及沉积速率的影响,并探究... 为探究镀液成分、工艺条件等因素对Ni-W合金镀层的影响,制备出低内应力、高硬度的Ni-W合金盘,用于金刚石的摩擦化学抛光。采用单一性实验分别探究络合剂浓度、溶液pH、糖精钠浓度对镀层内应力、钨含量、硬度以及沉积速率的影响,并探究不同添加剂对镀层表面整平的效果。最终选用水杨醛为整平剂,并采用反向脉冲电流降低了镀层表面粗糙度,制备出硬度达HV 713,镀层厚度约为0.66 mm的Ni-W合金盘。使用合金盘对金刚石进行摩擦化学抛光,并探究合适的抛光工艺参数。在合金盘转速为8000 r/min,压力为40 N时,金刚石的抛光效果较好,其材料去除率为5.56μm/min,磨削比达0.394,金刚石表面粗糙度Sa为3.7 nm。使用传统铸铁盘对金刚石进行摩擦化学抛光,通过对比磨损参数发现,Ni-W合金盘能够达到更好的抛光效果。 展开更多
关键词 金刚石 nI-w合金 镀层内应力 摩擦化学抛光
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深冷轧制变形对新型Ni-W-Co-Ta高密度合金显微组织与性能的影响
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作者 舒康豪 熊毅 +5 位作者 厉勇 岳赟 陈正阁 查小琴 韩顺 王春旭 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第4期1214-1225,共12页
采用熔炼-浇铸-锻造流程制备新型Ni-W-Co-Ta高强度合金,并对Ni-W-Co-Ta合金经深冷轧制变形后的显微组织及力学性能演变规律进行表征。结果表明:随着变形量的增加,新型Ni-W-Co-Ta高密度合金中等轴晶粒沿轧制方向不断被拉长,同时产生大量... 采用熔炼-浇铸-锻造流程制备新型Ni-W-Co-Ta高强度合金,并对Ni-W-Co-Ta合金经深冷轧制变形后的显微组织及力学性能演变规律进行表征。结果表明:随着变形量的增加,新型Ni-W-Co-Ta高密度合金中等轴晶粒沿轧制方向不断被拉长,同时产生大量的滑移带以协调剧烈的塑性变形,并最终形成纤维组织。变形量的增大导致位错密度急剧增大,位错交互作用显著加强,进而使晶粒尺寸细化至纳米量级;合金强度、硬度随着变形量的增加而显著提高,伸长率则急剧下降。断口形貌则由韧性断裂(未变形)向准解理-韧性混合型断裂转变(90%变形量)。 展开更多
关键词 ni-w-Co-Ta高密度合金 深冷轧制 纤维组织 力学性能 准解理-韧性混合型断裂
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2023年塔吉克斯坦M_(W)7.2地震InSAR同震形变场与滑动分布
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作者 字城岱 滕兴发 +3 位作者 关舒丹 闫高翔 刘森平 白运峰 《大地测量与地球动力学》 CSCD 北大核心 2024年第3期234-239,共6页
利用Sentinel-1A卫星SAR影像数据,对2023年塔吉克斯坦M_(W)7.2地震开展同震形变提取,基于弹性位错模型进行断层反演,并以本文反演得到的右旋节面解为接收面,计算不同深度的静态库仑应力。同震形变结果显示,升轨LOS向最大形变量达15 cm,... 利用Sentinel-1A卫星SAR影像数据,对2023年塔吉克斯坦M_(W)7.2地震开展同震形变提取,基于弹性位错模型进行断层反演,并以本文反演得到的右旋节面解为接收面,计算不同深度的静态库仑应力。同震形变结果显示,升轨LOS向最大形变量达15 cm,降轨LOS向最大形变量达16 cm。断层反演结果表明,此次地震最优发震断层走向为131.1°、倾角为85.7°,同震主滑移区分布在深度10~30 km范围内,以右旋走滑为主,最大滑移位置位于地下约20 km深度处,滑移量为3.49 m,未破裂至地表,矩震级为M_(W)7.16。库仑应力结果显示,该区域库仑应力符合帕米尔高原已有的应力场及地质学研究结果,随着深度增加,其影响范围以发震断层为中心向外扩张,且自5 km深度往下,应力加载区逐渐侵蚀应力卸载区,并开始以加载区为主,在约10 km深度处开始发生余震活动,与本次发震断层相邻的2条断层未来短时间内地震风险性较小。 展开更多
关键词 塔吉克斯坦M_(w)7.2地震 InSAR同震形变场 断层滑动模型反演 同震静态库仑应力 地震风险性
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Stable multi-electron reaction stimulated by W doping VS_(4)for enhancing magnesium storage performance
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作者 Yuxin Tian Jiankang Chen +7 位作者 Guofeng Wang Bing Sun Alan Meng Lei Wang Guicun Li Jianfeng Huang Shiqi Ding Zhenjiang Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第2期89-98,I0004,共11页
Rechargeable magnesium batteries(RMBs)hold promise for offering higher volumetric energy density and safety features,attracting increasing research interest as the next post lithium-ion batteries.Developing high perfo... Rechargeable magnesium batteries(RMBs)hold promise for offering higher volumetric energy density and safety features,attracting increasing research interest as the next post lithium-ion batteries.Developing high performance cathode material by inducing multi-electron reaction process as well as maintaining structural stability is the key to the development and application of RMBs.Herein,multielectron reaction occurred in VS_(4)by simple W doping strategy.W doping induces valence of partial V as V^(2+)and V^(3+)in VS_(4)structure,and then stimulates electrochemical reaction involving multi-electrons in 0.5%W-V-S.The flower-like microsphere morphology as well as rich S vacancies is also modulated by W doping to neutralize structure change in such multi-electron reaction process.The fabricated 0.5%W-V-S delivers higher specific capacity(149.3 m A h g^(-1)at 50 m A g^(-1),which is 1.6 times higher than that of VS_(4)),superior rate capability(76 mA h g^(-1)at 1000 mA g^(-1)),and stable cycling performance(1500cycles with capacity retention ratio of 93.8%).Besides that,pesudocapaticance-like contribution analysis as well as galvanostatic intermittent titration technique(GITT)further confirms the enhanced Mg^(2+)storage kinetics during such multi-electron involved electrochemical reaction process.Such discovery provides new insights into the designing of multi-electron reaction process in cathode as well as neutralizing structural change during such reaction for realizing superior electrochemical performance in energy storage devices. 展开更多
关键词 Multi-electron reaction w doping Stable structure CATHODE Rechargeable magnesium batteries
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Potassium alleviated high nitrogen-induced apple growth inhibition by regulating photosynthetic nitrogen allocation and enhancing nitrogen utilization capacity
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作者 Xinxiang Xu Guangyuan Liu +10 位作者 Jingquan Liu Mengxue Lyu Fen Wang Yue Xing Hao Meng Min Li Yu Jiang Ge Tian Zhanling Zhu Yuanmao Jiang Shunfeng Ge 《Horticultural Plant Journal》 SCIE CAS CSCD 2024年第1期1-14,共14页
There is a close relationship between potassium(K)and nitrogen(N).However,the roles of K under high N conditions remain unclear.Using a hydroponics approach,we monitored the morphological,physiological,and molecular c... There is a close relationship between potassium(K)and nitrogen(N).However,the roles of K under high N conditions remain unclear.Using a hydroponics approach,we monitored the morphological,physiological,and molecular changes in M9T337 apple(Malus domestica)rootstocks under different nitrate(10 and 30 mmol·L^(-1)NO_(3)^(-))and K supply(0.5,6,10,and 20 mmol·L_(-1)K^(+))conditions.Results revealed that high nitrate inhibited the root growth of M9T337 rootstocks,downregulated the expressions of K transporter genes(MdPT5,MdHKT1,and MdATK1),and reduced the net NO3-and K+influx at the surface of roots,thereby resulting in an N/K imbalance in rootstocks.Further investigation showed that 10 mmol·L^(-1)K increased the activity of N metabolic enzymes(NR,GS,NiR,and GOGAT),upregulated the expressions of genes related to nitrate uptake and transport(MdNRT1.1,MdNRT1.2,MdNRT1.5,and MdNRT2.4),promoted15N transport from the roots to the shoots,optimized leaf N distribution,and improved photosynthetic N utilization efficiency under high nitrate conditions.These results suggest that the negative effects of high nitrate may be related to the N/K imbalance and that reducing N/K in plants by increasing K supply level can effectively alleviate the inhibition of N assimilation by high nitrate stress. 展开更多
关键词 Apple rootstock K level High nitrate stress n metabolism ^(15)n
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Effect of high-energy Ne ions irradiation on mechanical properties difference between Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5)metallic glass and crystalline W
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作者 李娜 张立松 +3 位作者 张小楠 宫丽悦 羌建兵 梅显秀 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第6期14-21,共8页
In this paper,high-energy Ne ions were used to irradiate Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) metallic glass(MG)and crystalline W to investigate their difference in mechanical response after irradiation.The results showed t... In this paper,high-energy Ne ions were used to irradiate Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) metallic glass(MG)and crystalline W to investigate their difference in mechanical response after irradiation.The results showed that with the irradiation dose increased,the tensile micro-strain increased,nano-hardness increased from 7.11 GPa to 7.90 GPa and 8.62 GPa,Young’s modulus increased,and H3/E2 increased which indicating that the plastic deformability decreased in crystalline W.Under the same irradiation conditions,the Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) MG still maintained the amorphous structure and became more disordered despite the longer range and stronger displacement damage of Ne ions in Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) MG than in crystalline W.Unlike the irradiation hardening and embrittlement behavior of crystalline W,Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) MG showed the gradual decrease in hardness from 6.02 GPa to 5.89 GPa and 5.50 GPa,the decrease in modulus and the increase in plastic deformability with the increasing dose.Possibly,the irradiation softening and toughening phenomenon of Zr_(63.5)Cu_(23)Al_(9)Fe_(4.5) MG could provide new ideas for the design of nuclear materials. 展开更多
关键词 heavy ions irradiation displacement damage metallic glass crystalline w mechanical property
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软装设计用铜合金的表面Ni-W-P镀层与性能研究
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作者 杨凱智 宗彦 吴克凡 《电镀与精饰》 CAS 北大核心 2024年第5期65-71,共7页
针对软装设计用铜合金复杂服役环境的使用需求,为解决铜合金表面硬度低、耐腐蚀性能差等问题,采用化学镀的方法在软装设计用铜合金表面制备了Ni-W-P镀层。研究了Na_(2)WO_(4)浓度对化学镀层沉积速率、表面形貌、物相组成、硬度和耐腐蚀... 针对软装设计用铜合金复杂服役环境的使用需求,为解决铜合金表面硬度低、耐腐蚀性能差等问题,采用化学镀的方法在软装设计用铜合金表面制备了Ni-W-P镀层。研究了Na_(2)WO_(4)浓度对化学镀层沉积速率、表面形貌、物相组成、硬度和耐腐蚀性能的影响。结果表明:随着Na_(2)WO_(4)浓度从15 g/L增加至65 g/L,铜合金表面镀层的沉积速率先增后减,在Na_(2)WO_(4)浓度为35 g/L时取得最大值。镀层中P元素含量逐渐减小,W元素含量先增加后减小。不同Na_(2)WO_(4)浓度的镀层中都可见Ni和Ni_(5)P_(4)衍射峰,镀层硬度高于未添加Na_(2)WO_(4)的镀层。且随着Na_(2)WO_(4)浓度增加,镀层硬度先增后减,在Na_(2)WO_(4)浓度为35 g/L时取得最大值。随着Na_(2)WO_(4)浓度从15 g/L上升至65 g/L,铜合金表面镀层的腐蚀电位先正向移动后负向移动,腐蚀电流密度先减小后增大。在Na_(2)WO_(4)浓度为35 g/L时,取得腐蚀电流密度最小值和电荷转移电阻最大值。电化学阻抗谱与极化曲线测试结果相吻合,Na_(2)WO_(4)浓度为35 g/L时具有最佳的耐腐蚀性能。 展开更多
关键词 铜合金 na_(2)wO_(4)浓度 ni-w-P镀层 显微形貌 耐腐蚀性能
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Inactivated H9N2 vaccines developed with early strains do not protect against recent H9N2 viruses:Call for a change in H9N2 control policy
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作者 Yanjing Liu Qingqing Yu +8 位作者 Xiangyu Zhou Wenxin Li Xinwen He Yan Wang Guohua Deng Jianzhong Shi Guobin Tian Xianying Zeng Hualan Chen 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第6期2144-2148,共5页
H9N2 virus has been widely distributed in wild birds and poultry around the world since its first emergence in the United States of America in 1966(Gu et al.2017;Carnaccini and Perez 2020).The virus appeared in chicke... H9N2 virus has been widely distributed in wild birds and poultry around the world since its first emergence in the United States of America in 1966(Gu et al.2017;Carnaccini and Perez 2020).The virus appeared in chickens in China in the early 1990s,and over the last two decades has gradually become the dominant epidemic subtype(Sun and Liu 2015;Bi et al.2020).Although H9N2 virus infection alone cannot cause severe disease or death in poultry,H9N2 virus-infected birds experience a degree of egg production drop and can be easily infected by other pathogens,thus causing economic losses for poultry industry. 展开更多
关键词 H9n2 POULTRY policy
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Comparative Study on Microstructure and Mechanical Properties of Coarse-grained WC-based Cemented Carbides Sintered with Ultrafine WC or (W+C) as Additives
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作者 于淞百 闵凡路 +6 位作者 LI De NOUDEM Guillaume Jacques ZHANG Hailong MA Jichang ZHAO Kui YAO Zhanhu 张建峰 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第2期399-409,共11页
The effects of ultrafine WC(WC_(UF),0.5μm) or W(1μm) and C(0.3μm)(W+C)_(UF) additives on the densification,microstructure and mechanical properties of coarse-grained cemented carbides were compared systematically.O... The effects of ultrafine WC(WC_(UF),0.5μm) or W(1μm) and C(0.3μm)(W+C)_(UF) additives on the densification,microstructure and mechanical properties of coarse-grained cemented carbides were compared systematically.Overall,the cemented carbides with WC_(UF)/(W+C)_(UF) additives are almost fully densification to be higher than 99%,and the average grain size is kept above 2.8μm.The WC_(UF) additive assists grains to(truncated)trigonal prism shape by two dimensional(2D) growth,whereas the(W+C)_(UF) additive assists grains to rounded shape by three dimensional(3D) growth,lowers WC contiguity and increases face-centered-cubic Co.The hardness and bending strength of(75WC_(C)-15WC_(UF))-10Co are 86.6 HRA and 2 272 MPa,respectively,both higher than those of(75WC_(C)-15(W+C)_(UF))-10Co,which could be ascribed to the enhanced densification and unblemished grains.However,the fracture toughness of the(75WC_(C)-15(W+C)_(UF))-10Co is 23.5 MPa·m^(1/2),higher than that of the(75WC_(C)-15WC_(UF))-10Co due to the uniform WC-Co structure and flexible binder phase. 展开更多
关键词 coarse-grained wC-based cemented carbide ultrafine wC ultrafine(w+C) microstructure mechanical properties
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Impact on Soil Organic C and Total Soil N from Cool- and Warm-Season Legumes Used in a Green Manure-Forage Cropping System
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作者 Clark B. Neely Francis M. Rouquette Jr. +3 位作者 Cristine L.S. Morgan Frank M. Hons William L. Rooney Gerald R. Smith 《Agricultural Sciences》 2024年第3期333-357,共25页
Annual forage legumes are important components of livestock production systems in East Texas and the southeastern US. Forage legumes contribute nitrogen (N) to cropping systems through biological N fixation, and their... Annual forage legumes are important components of livestock production systems in East Texas and the southeastern US. Forage legumes contribute nitrogen (N) to cropping systems through biological N fixation, and their seasonal biomass production can be managed to complement forage grasses. Our research objectives were to evaluate both warm- and cool-season annual forage legumes as green manure for biomass, N content, ability to enhance soil organic carbon (SOC) and soil N, and impact on post season forage grass crops. Nine warm-season forage legumes (WSL) were spring planted and incorporated as green manure in the fall. Forage rye (Secale cereale L.) was planted following the incorporation of WSL treatments. Eight cool-season forage legumes (CSL) were fall planted in previously fallow plots and incorporated as green manure in late spring. Sorghum-sudangrass (Sorghum bicolor x Sorghum bicolor var. sudanense) was planted over all treatments in early summer after forage rye harvest and incorporation of CSL treatments. Sorghum-sudangrass was harvested in June, August and September, and treatments were evaluated for dry matter and N concentration. Soil cores were taken from each plot, split into depths of 0 to 15, 15 to 30 and 30 to 60 cm, and soil C and N were measured using combustion analysis. Nylon mesh bags containing plant samples were buried at 15 cm and used to evaluate decomposition rate of above ground legume biomass, including change in C and N concentrations. Mungbean (Vigna radiata L. [Wilczek]) had the highest shoot biomass yield (6.24 t DM ha<sup>-1</sup>) and contributed the most total N (167 kg∙ha<sup>-1</sup>) and total C (3043 kg∙ha<sup>-1</sup>) of the WSL tested. Decomposition rate of WSL biomass was rapid in the first 10 weeks and very slow afterward. Winter pea (Pisum sativum L. spp. sativum), arrow leaf clover (Trifolium vesiculosum Savi.), and crimson clover (Trifolium incarnatum L.) were the most productive CSL in this trial. Austrian winter pea produced 8.41 t DM ha<sup>-1</sup> with a total N yield of 319 kg N ha<sup>-1</sup> and total C production of 3835 kg C ha<sup>-1</sup>. The WSL treatments had only small effects on rye forage yield and N concentration, possibly due to mineralization of N from a large SOC pool already in place. The CSL treatments also had only minimal effects on sorghum-sudangrass forage production. Winter pea, arrow leaf and crimson clover were productive cool season legumes and could be useful as green manure crops. Mungbean and cowpea (Vigna unguiculata [L.] Walp.) were highly productive warm season legumes but may include more production risk in green manure systems due to soil moisture competition. 展开更多
关键词 Annual Legumes Soil n Soil Organic C Green Manure Deer Browse Forage Cropping Systems
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Source model of the 2018 M_(w)7.5 Papua New Guinea earthquake constrained by InSAR measurements: Insight into a blind rupture beneath the New Guinea Highlands
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作者 Wei Chen Tianchen Sheng Wei Xiong 《Geodesy and Geodynamics》 EI CSCD 2024年第4期315-325,共11页
The Southern Highland Fold and Thrust Belt(SHFTB),the boundary of the Australian plate and the New Guinea Highland block,significantly contributes to the convergent deformation along the plate bound-ary.However,due to... The Southern Highland Fold and Thrust Belt(SHFTB),the boundary of the Australian plate and the New Guinea Highland block,significantly contributes to the convergent deformation along the plate bound-ary.However,due to the lack of observation data,the detailed slip pattern of the SHFTB and the orogenic mechanism beneath the New Guinea Highlands remains controversial.On 25 February 2018,the M_(w)7.5 Papua New Guinea(PNG)earthquake struck the southeastern segment of the SHFTB.The detailed rupture characteristics of this event is significant for further clarifying the inter-seismic slip pattern along the SHFTB.Here,the coseismic deformation field of this earthquake was obtained using high-resolution ALOS-2 satellite images.We find that the 2018 M_(w)7.5 PNG earthquake ruptured a large-scaled fault(SHFTB)extending to the lower crust(deeper than 20 km)beneath the New Guinea Highlands,with a dip angle of 24°.The slips on the fault plane are equivalent to moment magnitudes of M_(w)7.51.Three major asperities with thrust-dominated slip of up to 3.94 m are detected on the fault plane.This finding implies that the slip pattern on the eastern segment of the SHFTB is dominated by thrust,rather than with significant sinistral movement,as previously reported.The tectonic deformation across the New Guinea Highlands is possibly concentrated on the large-scale fault SHFTB and primarily controls the intra-continental orogeny in the central Papua New Guinea. 展开更多
关键词 2018M_(w)7.5PapuanewGuineaearthquake The Southern Highlands Fold-and-Thrust Belt InSAR Slipdistribution Seismicrisk
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花岗岩Sn-W-Nb-Ta-Rb-Cs-Li成矿作用的研究方法——以滇西南大同山稀土矿区土壤化探异常查证为例
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作者 顾光明 李杭 +6 位作者 严城民 周家喜 马重辉 罗伟 周坤 高爱奎 雷星 《矿产勘查》 2024年第7期1204-1214,共11页
滇西南大同山稀土矿区位于临沧花岗岩中南段,基岩主要为三叠纪黑云母二长花岗岩,属“S”型花岗岩,形成于同碰撞环境。临沧花岗岩分布区为Sn、W、Bi、B、Li、Rb、Cs、Pb、As、Sb高丰度区,在矿区内La-Y-Nb组合异常,但未进行检查。在矿区1... 滇西南大同山稀土矿区位于临沧花岗岩中南段,基岩主要为三叠纪黑云母二长花岗岩,属“S”型花岗岩,形成于同碰撞环境。临沧花岗岩分布区为Sn、W、Bi、B、Li、Rb、Cs、Pb、As、Sb高丰度区,在矿区内La-Y-Nb组合异常,但未进行检查。在矿区1∶50 000土壤地球化学调查中,圈定了16个综合异常。异常查证中,在13个综合异常区的半风化—微风化花岗岩中共采集19件化学分析样,分析了与综合异常相关的7种元素(Sn、W、Nb、Ta、Rb、Cs、Li)。本研究中总结了4种方法:(1)经岩石类型分析数值比较,除中粗粒黑云母二长花岗岩(ηγ^(c)T)与Cs_(2)O矿化有较密切关系外,其他岩石类型与矿化无明显关系;(2)通过样品分析数值比较,将样品划分为矿化元素、矿化程度不同的4种类型;(3)通过矿化系数分析,矿区可能存在Sn-W矿化、Rb-Cs矿化;(4)通过成矿系数分析,矿种的平均成矿系数由大至小为Rb_(2)O(0.6929)→Nb_(2)O_(5)(0.1445)→Cs_(2)O(0.0626)→Ta_(2)O_(5)(0.0378)→WO_(3 )(0.0195)→Sn(0.0101)→Li_(2)O(0.0098)。这4种研究方法对研究临沧花岗岩的成矿作用、进行成矿预测有较为重要的指导作用。在地质背景相似的地区寻找相似矿种,也可借鉴本文提出的研究方法。 展开更多
关键词 花岗岩 Sn-w-nb-Ta-Rb-Cs-Li 分析数值比较 矿化系数分析 成矿系数分析 大同山稀土矿床
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