基于Hatch滤波的改进矩阵变换法在BDS多频模糊度解算中的应用

长基线条件下,空间相关性弱,电离层延迟残差和噪声影响变大,致使矩阵变换法模糊度解算过程中,窄巷组合受噪声影响大,单历元模糊度解算成功率低。因此,削弱电离层残差及噪声影响可以一定程度提高模糊度解算成功率。本文在分析矩阵变换算法基础上,利用Hatch滤波有效抑制伪距测量噪声和多径效应特点,结合弱电离层、低噪声的载波组合,通过相位平滑伪距代替组合伪距值参与解算,从而削弱电离层残差及观测噪声影响。通过实测数据分析,本文算法可有效提高矩阵变换法模糊度解算成功率。

tRNA^(Glu)-derived fragments from embryonic extracellular vesicles modulate bovine embryo hatching

Transfer RNA-derived small RNAs(tsRNAs)have been shown to be involved in early embryo development and repression of endogenous retroelements in embryos and stem cells.However,it is unknown whether tsRNAs also regulate embryo hatching.In this study,we mined the sequencing data of a previous experiment in which we demonstrated that the microRNA(miRNA)cargo of preimplantation embryonic extracellular vesicles(EVs)influences embryo development.We thus profiled the tsRNA cargo of EVs secreted by blastocysts and non-blastocysts.The majority of tsRNAs was identified as tRNA halves originating from the 5'ends of tRNAs.Among the 148 differentially expressed tsRNAs,the 19 nt tRNA fragment(tRF)tDR-14:32-Glu-CTC-1 was found to be significantly up-regulated in EVs derived from non-blastocysts.RT-qPCR assays confirmed its significant up-regulation in non-blastocyst embryos and their conditioned medium compared to the blastocyst group(P<0.05).Inhibition of tDR-14:32-Glu-CTC-1 by supplementing antagomirs to the conditioned medium improved embryo hatching(P<0.05).Transcriptomic analysis of embryos treated with tDR-14:32-Glu-CTC-1 antagomirs further showed differential expression of genes that are associated with embryo hatching and implantation.In summary,tDR-14:32-Glu-CTC-1 is up-regulated in non-blastocyst embryos and their secretions,and inhibition of tDR-14:32-Glu-CTC-1 promotes embryo hatching,while influencing embryo implantation-related genes and pathways.These results indicate that embryonic EVs containing specific tRFs may regulate preimplantation embryo development.

HATCH评分、APPLE评分在心房颤动患者射频消融术后复发的预测价值研究

目的探讨HATCH评分、APPLE评分在心房颤动(房颤)患者射频消融术后复发的预测价值。方法选取2018年5月至2020年6月于秦皇岛市第一医院心血管内科行射频消融术治疗的105例房颤患者的临床资料进行回顾性分析,观察手术时间、X线曝光时间、消融成功率及复发率;且根据术后3个月后是否出现持续时间≥30 s的快速性房性心律失常分为复发组(n=36)和未复发组(n=69),分析影响复发的危险因素,评估HATCH评分、APPLE评分及两项联合评估房颤患者术后复发的AUC值、敏感度、特异度。结果105例房颤患者均顺利完成射频消融术,消融成功率为65.71%,复发率为34.29%。复发组与未复发组在性别、年龄、病程、合并高血压、糖尿病、心力衰竭、估算的肾小球滤过率(eGFR)、持续性房颤、左心室大小、左室射血分数(LVEF)、右室前后径、升主动脉内径、肺动脉主干内径、室内隔厚度、左室后壁厚度、主动脉瓣口血流速度、肌酐等资料比较中,差异均无统计学意义(P>0.05);而在左心房大小、E峰、HATCH评分、APPLE评分等比较中,差异具有统计学意义(P<0.05)。二元Logistic回归分析显示,左心房大小、E峰、HATCH评分、APPLE评分是影响手术治疗后复发的独立危险因素(P<0.001)。ROC曲线分析显示,HATCH评分、APPLE评分及两项联合评估房颤患者术后复发的AUC值分别为(0.747、0.807、0.927,P<0.05);敏感度分别为44.40%、69.40%、94.40;特异度分别为91.30%、85.50%、84.10%。结论HATCH评分、APPLE评分预测房颤患者射频消融术后复发具有一定价值,且两项联合有利于提高敏感度,能为识别术后复发提供指导。

Effects of Dietary Straw Content on Growth and Development of Locusta migratoria and Its Egg Hatching

[Objectives]This study was conducted to investigate the effects of dietary straw content on the growth and development of oriental migratory locusts(Locusta migratoria),as well as the effects of temperature and substrate on their egg hatching.[Methods]The eggs of oriental migratory locusts were hatched at 15,20,25,30,35,and 40℃in sawdust,soil and sawdust+soil conditions,respectively,to determine suitable environmental conditions for artificial hatching of oriental migratory locusts.Rice straw was added at 0%,20%,40%,60%,80%and 100%to the basic diet,and the obtained diets was feed to oriental migratory locusts at the 4^(th)instar,to investigate the effects on their growth and development.[Results]The eggs of oriental migratory locusts had a good hatching rate at 25-30℃,and sawdust was the best choice for their hatching substrate.Adding 40%of rice straw to the diet could ensure the normal growth and development of oriental migratory locusts while consuming as much rice straw as possible.[Conclusions]This study explored a technical solution for efficiently producing insect protein from discarded crop straw(treating waste with insects,and turning waste into treasure),providing support for breeding of oriental migratory locusts and locust disaster prevention.

基于Hatch载波相位平滑算法的Galileo双频精密单点定位性能研究

为评估Hatch载波相位平滑算法对精密单点精度的影响,以多个MGEX跟踪站数据为解算数据,进行了滤波前后Galileo双频精密单点定位解算实验。实验结果表明,E1/E5a、E1/E5b双频组合精密单点定位精度可以达到厘米级,而E5a/E5b双频组合精密单点定位精度较差,不适合进行组合定位。Hatch载波相位平滑算法能在一定程度上提升Galileo双频精密单点定位精度,但提升程度较小,提升量都在10%以内。

HATCH评分系统对典型心房扑动导管消融术后患者新发心房颤动的预测价值

目的分析HATCH评分系统对典型心房扑动导管消融术后患者新发心房颤动的预测价值。方法选取2014年1月至2019年1月于河南省人民医院心血管内科接受导管消融的110例典型心房扑动患者为研究对象,所有患者均使用HATCH评分系统进行评分,并对导管消融后新发心房颤动发生情况随访。分析评分结果与新发心房颤动发生的关系,评价该评分系统对典型房扑导管消融术后新发心房颤动的预测价值。结果平均随访(28.85±18.26)个月后,43例患者(39.09%)发生新发心房颤动。多因素Cox回归分析显示HATCH积分与新发心房颤动独立相关(风险比:4.484;95%可信区间:2.152~9.343,P<0.001)。ROC曲线显示HATCH评分为2分时,AUC值最大,预激的敏感性、特异性分别为51.2%、85.1%。HATCH≥2分组新发房颤发生率显著高于HATCH<2分组(68.75%vs.26.92%,P<0.05)。结论HATCH评分系统可用于典型心房扑动导管消融术后患者新发心房颤动的危险分层。

阵发性房颤患者HATCH评分与心电图V1导联P波终末电势的相关性研究

目的探讨阵发性房颤进展风险评分（HATCH评分）与心电图V1导联P波终末电势（PTFV1）的相关性,为阵发性房颤患者风险提供理论依据和预测指标。方法采用回顾性研究,测量2013-2015年100例非瓣膜性阵发性房颤患者的HATCH评分及PTFV1。100例非瓣膜性阵发性房颤患者按照房颤进展分为阵发性房颤组（阵发组,95例）和由阵发性房颤进展的持续性房颤组（进展组,5例）,分别比较两组间HATCH评分及PTFV1的差异。按照房颤病因分为孤立性房颤组（孤立组,20例）与病理性房颤组（病理组,80例）,分别比较两组间HATCH评分及PTFV1的差异。采用Spearman等级相关分析PTFV1与HATCH评分的相关性。结果 1100例非瓣膜性阵发性房颤患者PTFV1,与HATCH评分呈显著正相关（r=0.537,P〈0.05）;2HATCH评分1分组PTFV1略高于HATCH评分0分组,但差异无统计学意义（P〉0.05）;HATCH评分≥2分组PTFV1明显高于HATCH评分1分组,差异有统计学意义（P〈0.01）;3平均随访1年,由阵发性房颤进展的持续性房颤患者（进展组）HATCH评分及PTFV1明显高于仍为阵发性房颤患者（阵发组）,差异有统计学意义（P〈0.001）;病理组PTFV1和HATCH评分高于孤立组,差异有统计学意义（P〈0.001）。结论 PTFV1作为一种无创检查指标,可对预测阵发性房颤向持续性房颤进展有重要的临床指导意义。

基于码载偏离度的改进自适应Hatch滤波算法

针对单频地基增强系统(GBAS)中载波相位平滑伪距精度易受电离层延时和伪距测量噪声影响的问题,分析卫星信号码载偏离度对Hatch滤波器平滑精度影响,提出一种基于码载偏离度的自适应Hatch滤波算法。根据伪距和载波相位观测值计算码减载波,建立其1阶线性模型;在此基础上采用最小二乘法估计电离层延时变化率,由此分离得到伪距测量噪声;建立平滑后伪距误差均方根与电离层延时变化率、伪距测量噪声标准差以及Hatch滤波器平滑时间三者之间的函数模型,并根据该函数表达式计算得到滤波器最优平滑时间。利用GBAS原理样机进行了验证实验,结果表明:自适应Hatch滤波算法能够根据实时计算得到的电离层延时变化率和伪距测量噪声标准差确定滤波器最优平滑时间,且在机载差分定位中采用自适应Hatch滤波算法平滑伪距后其位置精度相比传统固定平滑时间算法最大提高了53.19%,验证了所提算法的有效性。

基于Hatch滤波法的GPS伪距差分定位分析

利用Hatch滤波法对导航数据进行伪距差分定位研究,对单频接收机采用Hatch滤波法时电离层的影响做进一步研究,分析电离层风暴对定位精度的影响。为了提高定位精度,采用Hatch滤波法辅助的差分定位技术,对解算过程进行详细分析,并通过MATLAB软件对数据进行处理仿真,验证利用差分Hatch滤波法提高定位精度的可行性。

基于IPSO-HATCH的北斗相位平滑伪距定位算法

载波相位平滑伪距可以有效地提高北斗伪距定位的解算精度,传统的Hatch滤波由于平滑窗口大小是固定的,在持续定位解算中容易发散,因此必须合理地选择平滑窗口的大小。通过分析平滑因子的影响因素,利用改进的粒子群算法(IPSO)对每一历元的平滑窗口大小进行寻优,确定最优平滑窗口的大小。实验表明,利用改进粒子群和Hatch组合的算法(IPSO-HATCH)能够有效地提升滤波效果和定位精度,解决了Hatch滤波平滑窗口大小选择的问题,证明了算法的有效性、稳定性和可靠性。

GBAS中抑制电离层异常的改进自适应Hatch滤波算法

针对单频地基增强系统(Ground Based Augmentation System,GBAS)中电离层异常时Hatch滤波器平滑精度降低问题,系统分析了电离层延时对Hatch滤波器平滑精度的影响,提出一种改进自适应Hatch滤波算法。根据卫星信号计算码载偏离度,并利用二阶线性时不变低通滤波器抑制码载偏离度高频信号,以实现电离层异常实时检测;建立平滑后伪距误差均方根与电离层延时变化率、伪距测量噪声标准差以及平滑时间三者之间的函数模型,并由此确定出Hatch滤波器最优平滑时间。利用GBAS原理样机进行验证实验,结果表明:自适应Hatch滤波算法能够根据卫星信号电离层延时变化率确定滤波器最优平滑时间,且当电离层异常时,自适应Hatch滤波器机载位置误差最大由1.15 m减小为0.43 m,从而验证了所提算法的有效性。

Effects of Thermal and Hydric Conditions on Egg Incubation and Hatchling Phenotypes in Two Phrynocephalus Lizards

Flexible-shelled eggs of the lizards Phrynocephalus przewalskii and P. versicolor were incubated under different thermal and hydric conditions to elicit the effects of incubation environment on hatching success, embryonic development and duration as well as hatchling phenotypes. Embryogenesis of the two species was not sensitive to changes in the hydric environment except P. przewalskii incubated in 30°C group. Temperature significantly altered the duration of embryogenesis, with cooler temperatures leading to a longer incubation period. Hatching success was greater at 26 and 30°C than at 34°C. The hatchlings incubated at 26 and 30°C had longer snout-vent length, larger body mass, and better locomotor performance than those incubated at 34°C. Compared to P. przewalskii, P. versicolor had a shorter incubation period and yielded smaller hatchlings, which then had a higher survival rate in cooler and drier habitats. We conclude that an incubation temperature of 30°C would produce the best balance among developmental rate, hatching success, and post-hatching performance. We speculate that the upper temperature limit for incubation of P. versicolor eggs may be slightly higher than 34°C.

Effects of Varying Temperature and Constant Temperature on Hatching Result of Fertilized Peacock Eggs

In order to investigate the effect of temperature on hatching result of fertilized peacock eggs, they were hatched under conditions of varying temperature and constant temperature respectively. The result shows that the hatching rate in the varying temperature treatment group （Group Ⅰ） is higher than that in the constant temperature treatment group （Group Ⅱ）. It suggests that the varying temperature treatment （high temperature in the early period, medium temperature in the middle period, slightly lower temperature in the late period, and slightly higher temperature in the hulling period） is in line with the optimum temperature variation in the hatching of fertilized peacock eggs, contributing the hatching of fertilized peacock eggs.

基于改进的Hatch滤波GPS/BD组合系统单点定位

通过研究GPS与北斗组合系统伪距单点定位,利用平滑伪距的方法提高了组合系统伪距单点定位的精度。本文首先采取了P码对C/A码伪距单点定位进行修正,之后利用常用的Hatch滤波模型,利用载波进行伪距平滑,但对Hatch滤波解算进行了改进,也是本文的核心部分,单一频率分段滤波,不需要求解整周模糊度和电离层改正的基础上,降低定位时间和成本的基础上,精度提高,速度更快,对观测时间要求更低。

AUTOCAD软件二次开发Hatch命令的实现——基于ObjectArx的开发

AutoCad2002及其后续版本的ObjectArx二次开发是面向对象程序发展的结果,在机械、建筑等领域有着广泛的应用,有巨大的市场需求。AutoCad命令的开发是二次开发中的一项重要内容。本文论述了hatch命令二次开发的设计过程和实现技术要点。

Assigning hatchlings to eggs:Is relative mass assignment an accurate method?

Background: Accurately assigning hatchlings to the eggs from which they hatched is a prerequisite to understanding how the composition and environment of eggs affect the growth and survival of nestlings. Correctly assigning hatchlings to their eggs can be a challenging endeavor, however, because multiple eggs within the same clutch can hatch at essentially the same time. Egg and hatchling mass are highly correlated in most bird species, and thus assigning eggs to hatchlings using their relative mass(e.g., matching the heaviest hatchling to the heaviest candidate egg) could prove extremely useful.Methods: To assess its potential utility, I applied relative mass assignment(RMA) retrospectively to a dataset of 133 Common Grackle(Quiscalus quiscula) nests in which all egg-hatchling dyads were determined unequivocally.Results: I found that RMA correctly assigned approximately 90% of hatchlings to their eggs when 2-4 hatchlings were present between checks. The number of nests in which hatchlings could not be assigned to their egg, however, increased monotonically from 13 to 46 to 78% for nests containing 2, 3, and 4 hatchlings, respectively, due to the greater likelihood that the mass of hatchlings or their candidate eggs was identical.Conclusions: Although RMA correctly identified the vast majority of egg-hatchling dyads, researchers should use this method with caution, because it will always inflate positive egg-size effects and thus could potentially result in erroneously reporting significant effects.

美国Hatch-Waxman法案及其对我国药品注册制的启示

介绍美国Hatch-Waxman法案的立法背景和主要内容,分析我国当前药品注册中专利保护的现状,并通过比较中美两国专利保护方法,对我国专利保护工作提供参考性建议。

心房颤动患者臂-踝脉搏波传导速度与HATCH评分的相关性

目的分析比较不同类型的房颤患者臂-踝脉搏波传导速度(baPWV)值,及其与HATCH评分的相关性。方法2012~2014年在大连医科大学附属第一医院住院的143例房颤患者及70例接受baPWV检查的非房颤患者作为对照组,收集患者的临床资料,包括年龄、性别、合并疾病及心脏超声测量的左房内径、左室内径等数值。并测量baPWV值,计算HATCH评分。将患者分为阵发性房颤组和持续性房颤组,比较各组baPWV、HATCH评分。并按照HATCH评分0分、1分和≥2分将房颤患者进行分组,比较各组baPWV,运用Spearman相关系数,分析baPWV和HATCH评分的相关性。结果持续性房颤组、阵发性房颤组的baPWV较对照组明显增高(P<0.05)。持续性房颤组、阵发性房颤组的HATCH评分较对照组明显增高,持续性房颤组的HATCH评分较阵发性房颤组明显增高(P<0.05)。baPWV与HATCH评分呈显著正相关(r=0.178,P=0.025)。结论baPWV与房颤的进展可能存在一定的相关性,并为临床判断房颤患者的转归提供新的参考。

改进的Hatch滤波平滑算法及RAIM性能分析

在比较不同Hatch滤波定权方法的基础上,提出了一种基于改正数、验后单位权中误差和卫星高度角适应权因子的Hatch滤波改进算法,该算法精度较高、具有一定的抗差性,能够解决基于高度角的Hatch滤波在高高度角卫星发生周跳时滤波不平滑的问题。实验结果表明,改进的Hatch滤波平滑算法的精度优于传统的Hatch滤波和基于高度角的Hatch滤波,有良好的伪距修复效果。当存在伪距偏差时,改进的Hatch滤波能够提高滑动开窗RAIM的可用性。