Results 31 to 40 of about 9,018 (165)
Methods in Ecology and Evolution, Volume 15, Issue 8, Page 1408-1421, August 2024.Abstract Environmental DNA (eDNA) monitoring of species distribution has become a critical tool in ecology, conservation biology and fisheries for identifying the presence and distribution of diverse organisms, including important, threatened and invasive species.
Jiwei Yang +4 more
wiley +1 more source
Guangtongxin yanjiu, 2008 文章介绍了与全球移动通信系统（GSM）接收灵敏度和有线接入移频直放站相关的基本概念,完整地计算出了极限工程应用环境下基站和直放站的接收灵敏度,并分析了不同的直放站上行链路增益分配对整个系统灵敏度的影响,最后给出直放站工程应用中合理分配链路增益以优化系统灵敏度的方法。
皮永辉, 彭显旭
doaj
Guangtongxin yanjiu, 2020 针对光纤布拉格光栅（FBG）超声探测传感器测量灵敏度和量程相互制约的问题,文章提出了一种基于法布里珀罗（FP）腔和π相移FBG（π-FBG）的解调方案。文章分析了利用FP腔解调的原理并进行了详细的数值仿真分析。理论分析表明,利用FP腔的两个纵模作为一组解调器同时解调,可将系统灵敏度提高两倍,并且具有很好的线性度。扩展到多个纵模时可构建解调器阵列,从而极大地提高了系统的量程,有效地解决了测量灵敏度和量程相互制约的问题。数值仿真结果表明,该方案在实际可操作参数范围内切实可行,并具有灵敏度高和响应速度快等优势。
高在青 +3 more
doaj
Greenhouse gas emissions from croplands of China [PDF]
, 2003 China possesses cropland of 1.33 million km 2. Cultivation of the cropland not only altered the biogeochemical cycles of carbon (C) and nitrogen (N) in the agroecosystems but also affected global climate.
Bohan, Liao +13 more
core +1 more source
Ultrasound in Obstetrics &Gynecology, Volume 64, Issue 1, Page 36-43, July 2024.ABSTRACT Objective Although remarkable strides have been made in fetal medicine and the prenatal diagnosis of congenital heart disease, around 60% of newborns with isolated coarctation of the aorta (CoA) are not identified prior to birth. The prenatal detection of CoA has been shown to have a notable impact on survival rates of affected infants.
C. A. Taksøe‐Vester +8 more
wiley +1 more source
Zhongguo shiyan zhenduanxue, 2013 目的利用结核分支杆菌噬菌体裂解法检测结核杆菌对利福平、异烟肼、链霉素敏感性。方法选用传统方法判定为利福平、异烟肼、链霉素的耐药或敏感菌株,采用噬菌体裂解法检测其对以上三种药物的敏感性,对比其特异性和敏感度。结果运用噬菌体裂解法检测结果显示,异烟肼药物浓度为1μg/ml时,其灵敏度为87.0%,特异度为93.3%,与传统方法的符合率为92.0%;链霉素药物浓度为4μg/ml时,其灵敏度为96.2%,特异度为92.0%,与传统方法的符合率为92.9%;利福平药物浓度为5μg/ml时,其灵敏度为91.4 ...
于宏波, 宋阳, 齐红, 韩忠波
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Preparation and Characterization of Semaphorin3Fc Monoclonal Antibody and the Preliminary Application [PDF]
, 2015 研究背景和目的 抑癌基因发生异常是癌症发生的机制之一。人类基因的很多区域发生改变时可导致细胞失控性生长。Sema3F作为肺癌19个候选抑癌基因之一，是Ⅲ型Semaphorin（即神经导向因子，最初作为Neuropilins的配体在神经系统中发挥排斥神经节轴突和调节神经系统发育的作用）家族的一个成员。目前有研究发现，与正常组织相比Sema3F蛋白在肿瘤细胞中的表达普遍存在下调的趋势，并在血管形成以及肿瘤增殖、凋亡、粘附和转移等中起着负向调节作用。此外，诸多体内或者体外实验已经证明 ...
李哲
core
Ultrasound in Obstetrics &Gynecology, Volume 64, Issue 1, Page 71-78, July 2024.ABSTRACT Objective To validate externally the QUiPP App v.2 algorithms in an independent cohort of high‐risk asymptomatic women attending a preterm birth (PTB) surveillance clinic in Ireland. Methods This was a retrospective, single‐center, observational study assessing discrimination and calibration of the QUiPP App v.2 at six predetermined clinical ...
L. Creswell +4 more
wiley +1 more source
Guangtongxin yanjiu, 2005 结合IEEE 802.3 ah标准中的以太无源光网络（EPON）接收灵敏度指标,着重分析了接收灵敏度光调制幅度（OMA）,该OMA指标的采用有利于系统降低对消光比的要求,使发射机和接收机的设计更加简单;最后,简要讨论了OMA和增强型接收灵敏度的测试,指出增强型测试更有实际意义。
杨立伟, 寿国础
doaj
Guangtongxin yanjiu, 2020 针对光纤温度传感装置普遍结构复杂且灵敏度偏低的问题,文章提出并仿真验证了一种具有高灵敏度的椭圆形气孔温度传感装置。利用表面等离子体技术与光纤温度传感技术相结合实现温度传感。在光纤外侧包覆一层金属膜,待测物质使用氯仿酒精混合物作为温度感应物质,通过有限元矢量软件COMSOL进行模拟仿真。仿真结果表明,当入射波长由0.5μm增加到1.0μm时,其温度测量区间为-20～120℃,可以得到最大光谱灵敏度6 nm/℃,分辨率为1 337.12 RIU-1,测量精度为2.85×10-5 RIU。
魏方皓, 张祥军, 唐守锋
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