二位点酶联免疫测定血浆P-选择素方法的建立及临床意义

血小板活化与血管内皮细胞损伤在动脉血栓形成中起着重要的作用。P-选择素是血小板α-颗粒膜蛋白,它在血小板活化和释放过程中随着α-颗粒膜与血小板浆膜的融合暴露在血小板表面,成为体内血小板活化和血栓形成的特异标志。P-选择素有两种形式,其一是具有跨膜区域的整合型,另一种为缺乏跨膜区的游离型,后者在血小板活化时,释放到血浆内,成为血浆P-选择素的主要来源。因此,测定血浆内P-选择素的浓度变化,对体内血小板活化及血栓形成亦具有重要诊断价值。我们利用二株抗P-选择素的单克隆抗体,建立了双克隆抗体二位点酶联免疫测定血浆内P-选择素的方法,并测定了正常人和某些血栓性疾病病人血浆内P-选择素的浓度,为血栓性疾病的诊断提供了一个新的方法。

葡萄叶片SPAD值与测定位置及光合色素含量的关系

为了实时、准确、无损地检测葡萄叶片中叶绿素的含量水平,以评价葡萄生长发育与营养状况,确保栽培的科学和施肥的合理,以‘夏黑’‘巨玫瑰’‘户太8号’‘阳光玫瑰’‘金手指’‘摩尔多瓦’这6个品种葡萄叶片为试验材料,采用叶绿素测定仪测定了6个葡萄品种叶片不同位置的SPAD值,使用分光光度计测定了葡萄叶片光合色素含量,探寻了葡萄叶片SPAD值的最适测量位点,分析了SPAD值与光合色素含量的关系,并建立了SPAD值与光合色素含量的线性函数拟合方程。结果表明:6个品种葡萄叶片的SPAD值,叶片顶部的均最高,中部的均次之,基部的均最小;其中,葡萄叶片中部的SPAD值最具有代表性。6个品种葡萄叶片的SPAD值与叶绿素a、叶绿素b、总叶绿素和类胡萝卜素含量均显著相关,其与叶绿素a含量的相关性最高;在不同品种葡萄叶片的SPAD值与叶绿素a、叶绿素总含量、类胡萝卜素含量的线性函数拟合方程中,‘户太8号’的拟合方程决定系数值最高,其叶绿素a、叶绿素总含量、类胡萝卜素含量的决定系数值分别为0.903 5、0.867 2、0.749 9;在叶绿素b与葡萄叶片SPAD值的拟合方程中,‘金手指’的拟合方程为y=0.034 7x-0.084 0,其决定系数R2值(0.773 4)最高。单一品种葡萄叶片的SPAD值与光合色素含量的回归模型的拟合准确率比6个葡萄品种汇总拟合回归模型的要高。

Transmission cable fault detector based on waveform reconstruction

In order to improve the accuracy of cable fault position location at a low cost and make the testing results intuitive, a cable fault detector based on wave form reconstruction is designed. In this detector, the cable fault position is located based on the time-domain pulse reflection （TDR） principle. A pulse waveform is injected in the tested cable, and a high-speed comparator with changeable reference voltages is used to binarize the test pulse waveform to a binary sequence on a certain voltage. Through scanning the reference voltage in a full voltage range, multi-sequences are acquired to reconstruct the pulse waveform transmission in the cable, and then the pulse attenuation feature, electrical open circuit fault, electrical short circuit fault, and the fault position of the cable are diagnosed. Experimental results show that the designed cable fault detector can determine the fault type and its position of the cable being tested, and the testing results are intuitive.

The Research of Indoor Positioning Based on Visible Light Communication

The key techniques in indoor positioning based on visible light communication and the state of the art of this research were surveyed. First, the significance of indoor positioning based on visible light communication from two aspects of the limitations of current indoor positioning technology and the advantages of visible light communication was discussed; And then, the main four technology of indoor positioning based on visible light communication were summarized and the triangulation of RSS method and the principle of image positioning were introduced in detail; Next, the performance characteristics of various typical algorithms were compared and analyzed; In the end, several suggestions on future research of indoor positioning based on visible light communication were given.

Land deformation monitoring in mining area with PPP-AR

The mining area deformation monitoring theory and method using precise point positioning （PPP） ambi- guity resolution （AR） were studied, and an ambiguity fixing model with satellite and receiver combina- tion phase delay （CPD） was proposed for zero-differenced PPP ambiguity fixing and its corresponding formula derivation was given. The data processing results for I h at six IGS stations in China show that 93% of ambiguities can be fixed within 10 min and all ambiguities can be fixed within 15 min. After ambi- guity fixing, the positioning accuracy is improved by more than 85% in the E and N directions, with abso- lute positioning accuracy reaching millimeter level, and it was improved by 70% in the U direction, reaching centimeter level; the proposed zero-differenced ambiguity fixing model can effectively improve the convergence rate and positioning accuracy in PPP. Data monitoring continuously conducted for half a year at four COPS stations of Shanxi China Coal Pingshuo Group validated the feasibility of using PPP in mining area deformation monitoring.

Position Group Contribution Method for Predicting the Normal Boiling Point of Organic Compounds

A new position group contribution model is proposed for the estimation of normal boiling data of organic compounds involving a carbon chain from C2 to C18.The characteristic of this method is the use of position distribution function.It could distinguish most of isomers that include cis-or trans-structure from organic compounds.Contributions for hydrocarbons and hydrocarbon derivatives containing oxygen,nitrogen,chlorine,bromine and sulfur,are given.Compared with the predictions,results made use of the most common existing group contribution methods,the overall average absolute difference of boiling point predictions of 417 organic compounds is 4.2 K;and the average absolute percent derivation is 1.0%,which is compared with 12.3 K and 3.2% with the method of Joback,12.1 K and 3.1% with the method of Constantinou-Gani.This new position contribution groups method is not only much more accurate but also has the advantages of simplicity and stability.

An RSSl Gradient-based AP Localization Algorithm

Recent rapid rise of indoor location based services for smartphones has further increased the importance of precise localization of Wi-Fi Access Point(AP).However,most existing AP localization algorithms either exhibit high errors or need specialized hardware in practical scenarios.In this paper,we propose a novel RSSI gradient-based AP localization algorithm.It consists of the following three major steps:firstly,it uses the local received signal strength variations to estimate the direction(minus gradient) of AP,then employs a direction clustering method to identify and filter measurement outliers,and finally adopts triangulation method to localize AP with the selected gradient directions.Experimental results demonstrate that the average localization error of our proposed algorithm is less than 2meters,far outperforming that of the weighted centroid approach.

灌木柳耐盐SNP位点的快速鉴定与标记开发

【目的】对灌木柳(Salix spp.)耐盐相关位点进行快速鉴定并开发单核苷酸多态性(SNP)标记,为耐盐灌木柳早期鉴定与品种选育提供参考。【方法】以耐盐和敏盐灌木柳无性系为亲本材料建立杂交组合,对子代进行盐胁迫并分别构建耐盐和敏盐混池,利用特定位点参数扩增测定(SLAF-seq)技术对亲本及混池进行简化基因组测序,开发多态性SLAF标签并利用SNP-index法进行关联分析。对候选SLAF标签序列进行功能注释,针对SNP位点设计引物并进行重测序验证。【结果】4个样本(含2个亲本及2个混池)SLAF测序平均Q30值为94.36%,GC含量为39.39%,测序深度为48.57×。测序共获得175468个SLAF标签,其中多态性标签25675个,占比14.63%。关联分析共筛选出与耐盐性状显著关联的SLAF标签18个,包含25个SNP位点。功能注释显示有6、4、3和1个标签序列分别在Nt、NOG、KEGG和Swiss-Prot数据库中有比对结果。重测序结果表明,开发的10个SNP标记在耐盐个体和敏盐个体间发生了碱基位点的替换,与原SLAF测序结果一致。【结论】本研究利用BSA分析方法结合SLAF测序技术可快速、有效地对目标性状进行初步定位与鉴别,可为柳树功能标记的开发及分子标记辅助育种提供理论依据和技术支持。

Extraction of line-of-sight ionospheric observables from GPS data using precise point positioning

Here we propose a method for extracting line-of-sight ionospheric observables from GPS data using precise point positioning(PPP).The PPP-derived ionospheric observables(PIOs) have identical form with their counterparts obtained from leveling the geometry-free GPS carrier-phase to code(leveling ionospheric observables,LIOs),and are affected by the satellite and receiver inter-frequency biases(IFBs).Based on the co-location experiments,the effects of extracting error arising from the observational noise and multipath on the PIOs and the LIOs are comparatively assessed,and the considerably reduced effects ranging from 70% to 75% on the PIOs with respect to the LIOs can be verified in our case.In addition,based on 26 consecutive days' GPS observations from two international GNSS service(IGS) sites(COCO,DAEJ) during disturbed ionosphere period,the extracted PIOs and LIOs are respectively used as the input of single-layer ionospheric model to retrieve daily satellite IFBs station-by-station.The minor extracting errors underlying the PIOs in contrast to the LIOs can also be proven by reducing day-to-day scatter and improving between-receiver consistency in the retrieved satellite IFBs values.

Orbit Fitting Based on Helmert Transformation

Orbit fitting is used in many GPS applications. For example, in Precise Point Positioning (PPP), GPS orbits (SP3 orbits) are normally retrieved either from IGS or from one of its Analysis Centers (ACs) with 15 minutes’ sampling, which is much bigger than the normal observation sampling. Therefore, algorithms should be derived to fit GPS orbits to the observation time. Many methods based on interpolation were developed. Using these methods the orbits fit well at the sampling points. However, these methods ignore the physical motion model of GPS satellites. Therefore, the trajectories may not fit the true orbits at the periods in between 2 sampling epochs. To solve this problem, we develop a dynamic approach, in which a model based on Helmert transformation is developed in GPS orbit fitting. In this orbit fitting approach, GPS orbits at sampling points are treated as pseudo-observations. Thereafter, Helmert transformation is built up between the pseudo-observations and dynamically integrated orbits at each epoch. A set of Helmert parameters together with corrections of GPS initial orbits are then modeled as unknown parameters. Results show that the final fit orbits have the same precision as the IGS final orbits.