Results 11 to 20 of about 22,393 (164)
Zhongshan Daxue xuebao. Yixue kexue ban, 2023 目的探讨磁共振表观弥散系数（ADC）评估磁共振引导聚焦超声术（MRgFUS）治疗子宫肌瘤效果的价值。方法回顾性分析佛山市中医院2018年1月至2022年10月期间56例接受MRgFUS治疗子宫肌瘤患者治疗前、治疗3月后和6月后的MRI及临床资料，比较患者病灶ADC值与肌瘤的体积，症状严重评分（SSS）和子宫肌瘤症状-生活质量问卷（UFS-QOL）评分的相关性。使用方差分析比较治疗前后相关数据的差异，采用Pearson法进行数据的相关性分析。结果56例患者治疗前及治疗3个月后、6个月后病灶ADC值［（1 ...
曾雪伟 +6 more
doaj +2 more sources
Zhongguo shiyan zhenduanxue, 2020 目的评价尿有形成分分析在住院患者尿路感染(UTI)筛查中的应用价值。方法对2018年4月-2018年10月于大连大学附属中山医院住院疑似尿路感染的患者清洁中段尿标本497例进行尿有形成分分析、尿定量细菌培养及菌种鉴定。结果尿有形成分分析仪检测白细胞数和细菌数的阈值为白细胞数64个/μL和细菌数880.6个/μL,以该阈值筛检住院患者尿路感染,其敏感度分别为80.00%和85.19%,特异度分别为79.28%和87.39%。白细胞计数和细菌计数ROC曲线下面积分别为0.860和0.917。结论 UF ...
唐祯臻, 范世珍, 林洁, 于波海
doaj
Nonlinear finite element analysis for seismic performance of high-strength concrete beam-column joints with new reinforcement details [PDF]
, 2006 Because the factors that affect the behavior of the beam-column joints are complicated, an experimental study alone is not sufficient. Therefore, a nonlinear finite element analysis was conducted to provide better understanding of the performance of the ...
Gan, L, Li, J, Pam, HJ
core
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
, 1982 本文给出钝头细长锥无粘、平衡和非平衡高超声速绕流流场的数值分析。对存在化学反应的空气,考虑了13种气体组分和22个化学反应,包括N_2、O_2和NO的振动松弛与离介过程之间的耦合反应。头部亚-跨声速区和后身高超声速区分别用直线法和有限差分法进行计算。在来流条件M_∞=20～26,Re_∞=(p_∞u_∞α)/μ_∞=1.5×10~3～5.5×10~6(α为头部半径)的参数范围内,给出了绕流流场和等离子体鞘层诸特性,如激波形状 ...
周正瑾, 马文驹, 高智
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Representation of obligate groundwater‐dwelling copepod diversity in European protected areas
Conservation Biology, EarlyView.Abstract Groundwaters sustain diverse surface ecosystems and are populated by metazoan species, mostly invertebrates, that provide fundamental ecological functions and are often of prominent conservation value due to narrow endemism and high phylogenetic rarity.
Francesco Cerasoli +7 more
wiley +1 more source
Jump risk and bid-ask spread under different strike price [PDF]
, 2016 期权的买卖价差和风险溢价问题一直是一个热点的话题，尽管有很多文章做了相关的研究，但是目前国内外均没有从跳跃风险的角度来研究期权市场的买卖价差问题。本文主要研究了在非完全市场下，期权的行权价格对于期权做市商买卖价差的影响。首先，本文先回顾了Amin（1993）的模型，即在跳跃风险的方差可以分散的情况下，可以得到市场均衡的唯一买卖价格，这比布莱克-斯科尔斯模型中得到的均衡价格要大。然后，本文假设跳跃风险的方差是不可分散的，通过均衡市场的理论推导出静态对冲和动态对冲两种情况下，期权做市商最大化效用的买卖价差 ...
朱丛骁
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Conservation Biology, EarlyView.Abstract Achieving global conservation policy goals requires the ability to set and measure progress toward science‐based targets for biodiversity. The species threat abatement and restoration (STAR) metric was developed to enable actors to set science‐based targets for species.
Louise Mair +17 more
wiley +1 more source
The Extension of Dual-channel Supply Chain Model Based on Strategic Customer WTP [PDF]
, 2016 电子商务和物流业的快速发展增加了顾客购物的便利性，很多制造商会在传统零售渠道的基础上，增加电子渠道来迎合顾客购物足不出户的愿望，节约了顾客的时间，大大提高了交易的效率，比如苹果、三星、海尔、联想等都采用传统渠道与电子渠道相结合的销售方式。电子渠道不仅吸引了制造商，也吸引了传统零售商，从而形成产品多渠道销售的模式。同时顾客也在多渠道中权衡利弊，做出最有利于自身的购买选择。本论文以双渠道供应链的战略顾客选择模型为基础，分别在顾客类型、销售时期、产品类型、销售渠道四个方面进行扩展，综合应用顾客剩余效用分析法 ...
赵洋
core
International Journal of Applied Linguistics, EarlyView.ABSTRACT Previous research has established the relationships between motivation, anxiety, teachers’ support, and self‐regulated learning (SRL) in English‐as‐a‐foreign‐language (EFL) learning. Most of the studies, however, have taken a variable‐centered approach in addressing the variable correlations, while learners’ characteristics and variable links ...
Yuhong Jiao, Barry Bai, Jing Li
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