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Phase Residual Estimations for PCVs of Spaceborne GPS Receiver Antenna and Their Impacts on Precise Orbit Determination of GRACE Satellites

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Chinese Journal of Aeronautics 2012年第4期25卷 631-639页

作者： tu jia GU Defeng WU Yi YI Dongyun College of Science National University of Defense TechnologyChangsha 410073China

In-flight phase center systematic errors of global positioning system（GPS） receiver antenna are the main restriction for improving the precision of precise orbit determination using dual-frequency *** approach is one of the valid methods for in-flight calibration of GPS receiver antenna phase center variations（PCVs） from ground *** this paper,followed by the correction model of spaceborne GPS receiver antenna phase center,ionosphere-free PCVs can be directly estimated by ionosphere-free carrier phase post-fit residuals of reduced dynamic orbit *** the data processing of gravity recovery and climate experiment（GRACE） satellites,the following conclusions are ***,the distributions of ionosphere-free carrier phase post-fit residuals from different periods have the similar systematic ***,simulations show that the influence of phase residual estimations for ionosphere-free PCVs on orbit determination can reach the centimeter ***,it is shown by in-flight data processing that phase residual estimations of current period could not only be used for the calibration for GPS receiver antenna phase center of foretime and current period,but also be used for the forecast of ionosphere-free PCVs in future period,and the accuracy of orbit determination can be well improved.

关键词： global positioning system precise orbit determination phase center variations phase residual estimation GRACE

Spaceborne GPS receiver antenna phase center offset and variation estimation for the Shiyan 3 satellite

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Chinese Journal of Aeronautics 2016年第5期29卷 1335-1344页

作者： Gu Defeng Lai Yuwang Liu Junhong Ju Bing tu jia College of Sciences National University of Defense Technology

In determining the orbits of low Earth orbit （LEO） satellites using spaceborne GPS, the errors caused by receiver antenna phase center offset （PCO） and phase center variations （PCVs） are gradually becoming a major limiting factor for continued improvements to accuracy. Shiyan 3, a small satellite mission for space technology experimentation and climate exploration, was developed by China and launched on November 5, 2008. The dual-frequency GPS receiver payload delivers 1 Hz data and provides the basis for precise orbit determination within the range of a few centimeters. The antenna PCO and PCV error characteristics and the principles influencing orbit determination are analyzed. The feasibility of PCO and PCV estimation and compensation in different directions is demonstrated through simulation and in-flight tests. The values of receiver antenna PCO and PCVs for Gravity Recovery and Climate Experiment （GRACE） and Shiyan 3 satellites are estimated from one month of data. A large and stable antenna PCO error, reaching up to 10.34 cm in the z-direction, is found with the Shiyan 3 satellite. The PCVs on the Shiyan 3 satellite are estimated and reach up to 3.0 cm, which is slightly larger than that of GRACE satellites. Orbit validation clearly improved with independent k-band ranging （KBR） and satellite laser ranging （SLR） measurements. For GRACE satellites, the average root mean square （RMS） of KBR residuals improved from 1.01 cm to 0.88 cm. For the Shiyan 3 satellite, the average RMS of SLR residuals improved from 4.95 cm to 4.06 cm.

关键词： GRACE Phase center offset Phase center variations Shiyan 3 Spaceborne GPS

Root stoichiometric dynamics and homeostasis of invasive species Phyllostachys edulis and native species Cunninghamia lanceolata in a subtropical forest in China

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Journal of Forestry Research 2021年第5期32卷 2001-2010页

作者： Chao Peng jia tu Ming Yang Yong Meng Meiqun Li Wensheng Ai Institute of Bamboo Research Hunan Academy of ForestryChangsha 410004Hunan ProvinceP.R.China

The community species abundance and diversity declined with bamboo invasion had been widely reported ***,the physiological strategies used during root competition between native species and invasive bamboo are poorly *** clarify the mechanisms underlying such strategies,the stoichiometric dynamics and homeostasis of nitrogen,phosphorus,organic carbon in root orders of Phyllostachys edulis(I du[=Ⅰ-Pe,years 1 and 2];Ⅱdu[=Ⅱ-Pe,years 3 and 4]),Cunninghamia lanceolata in transition and pure forests were *** increasing intensity of bamboo invasion,N,P,and C content of *** root orders declined,N and P content in *** rhizome orders declined,while C increased,the stoichiometric ratios in mixed forest interface mainly increased,and the stoichiometric differences within native and invasive species root orders ***,the stoichiometric homeostasis index(H)of elements in the same root order and even the same elements in different root orders were not consistent.H of most root orders(except some HP)was greater than 4,the H ranked order wasⅠ-Pe>Cl>Ⅱ-Pe in mixed interfaces,and the N:P ratio of most species root orders was greater than 16,despite being affected by *** research concluded that the bamboo invasion narrows stoichiometric differences within root orders,and the juvenile bamboo rhizome has a stronger capacity for homeostatic regulation than in adult bamboo and ***,which is a key determinant of bamboo invasion success.

关键词： Bamboo invasion Root orders Nutrient dynamics Homeostatic regulation coefficient

Optimization and characterization of deoxypodophyllotoxin loaded mPEG-PDLLA micelles by central composite design with response surface methodology

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Chinese Journal of Natural Medicines 2018年第6期16卷 471-480页

作者： YU Ying-Lan LI Ya-Nan ZHANG Yong SUN Ru-Ning tu jia-Sheng SHEN Yan Department of Pharmaceutics School of PharmacyChina Pharmaceutical UniversityNanjing 210009China Children's Hospital of Nanjing Medical University Nanjing 210008China Department of Professional Institute China Pharmaceutical UniversityNanjing 210009China

The therapeutic application of deoxypodophyllotoxin(DPT) is limited due to its poor water solubility and stability. In the present study, the micelles assembled by the amphiphilic block copolymers(m PEG-PDLLA) were constructed to improve the solubility and safety of DPT for their in vitro and in vivo application. The central composite design was utilized to develop the optimal formulation composed of 1221.41 mg m PEG-PDLLA, the weight ratio of 1 : 4(m PEG-PDLLA : DPT), 30 m L hydration volume and the hydration temperature at 40 oC. The results showed that the micelles exhibited uniformly spherical shape with the diameter of 20 nm. The drug-loading and entrapment efficiency of deoxypodophyllotoxin-polymeric micelles(DPT-PM) were about(20 ± 2.84)% and(98 ± 0.79)%, respectively, indicating that the mathematical models predicted well for the results. Compared to the free DPT, the cytotoxicity showed that blank micelles possessed great safety for Hela cells. In addition, the DPT loaded micelle formulation achieved stronger cytotoxicity at the concentration of 1 × 10^(-7) mol·L^(-1), which showed significant difference from free DPT(P tumor therapy with DPT.

关键词： Deoxypodophyllotoxin Central composite design Micelles Cytotoxicity

Lysophosphatidylcholine binds α-synuclein and prevents its pathological aggregation

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National Science Review 2024年第6期11卷 119-128页

作者： Chunyu Zhao jia tu Chuchu Wang Wenbin Liu Jinge Gu Yandong Yin Shengnan Zhang Dan Li jiajie Diao Zheng-jiang Zhu Cong Liu Interdisciplinary Research Center on Biology and Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences University of Chinese Academy of Sciences Bio-X Institutes Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders Ministry of Education Shanghai Jiao Tong University Zhangjiang Institute for Advanced Study Shanghai Jiao Tong University Department of Cancer Biology University of Cincinnati College of Medicine

Accumulation of aggregated α-synuclein(α-syn) in Lewy bodies is the pathological hallmark of Parkinson's disease(PD). Genetic mutations in lipid metabolism are causative for a subset of patients with Parkinsonism. The role of α-syn's lipid interactions in its function and aggregation is recognized, yet the specific lipids involved and how lipid metabolism issues trigger α-syn aggregation and neurodegeneration remain unclear. Here, we found that α-syn shows a preference for binding to lysophospholipids(LPLs),particularly targeting lysophosphatidylcholine(LPC) without relying on electrostatic interactions. LPC is capable of maintaining α-syn in a compact conformation, significantly reducing its propensity to aggregate both in vitro and within cellular environments. Conversely, a reduction in the production of cellular LPLs is associated with an increase in α-syn accumulation. Our work underscores the critical role of LPLs in preserving the natural conformation of α-syn to inhibit improper aggregation, and establishes a potential connection between lipid metabolic dysfunction and α-syn aggregation in PD.

关键词： α-synuclein Parkinson's disease lysophosphatidylcholine, aggregation

放大转发OFDM中继系统的一种叠加导频辅助信道估计和联合数据检测算法

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高技术通讯 2011年第2期21卷 124-131页

作者：屠佳蔡跃明解放军理工大学通信工程学院南京210007

针对源节点和目的节点之间没有直接路径的放大转发（AF）OFDM中继系统，提出了一种利用叠加导频（SP）进行信道估计和联合数据检测的算法。该算法首先将接收信号通过白化滤波器进行信号白化，然后利用SP获得等效信道的信道状态信息（CS... 详细信息

针对源节点和目的节点之间没有直接路径的放大转发（AF）OFDM中继系统，提出了一种利用叠加导频（SP）进行信道估计和联合数据检测的算法。该算法首先将接收信号通过白化滤波器进行信号白化，然后利用SP获得等效信道的信道状态信息（CSI）初始估计值，并联合目的节点上的最大比合并（MRC）接收机，通过判决反馈迭代操作不断改进信道估计的性能。据此算法推导出了使用白化滤波器的AFOFDM系统平均误符号率（ASER）的理论闭式表达式。理论分析和仿真结果表明，由于使用叠加导频，此算法在提高系统频谱利用率的同时，能够获得较好的信道估计和数据检测性能。

关键词：放大转发(AF) 中继正交频分复用(OFDM) 叠加导频(SP) 信道估计

Small Interfering RNA Targeting MDR1 Inhibits Ovarian Cancer Growth and Increases Efficacy of Chemotherapy in vivo

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Chinese Journal of Cancer Research 2009年第4期21卷 318-324页

作者： Fu-jun LIU Guo-lan Gao Kai-jia tu Li-qun Yu Jun Gao Department of Obstetrics and Gynecology the First Affiliated Hospital Nanchang University Nanchang 330006 China Department of Obstetrics and Gynecology the Second Affiliated Hospital Nanchang University Nanchang 330006 China.

Objective： To further validate a knockdown approach for circumventing the multidrug resistance gene （MDR1）, we used small interfering RNA（siRNA） targeting MDR1 gene to inhibit the expression of MDR1 gene and P-glycoprotein（P-gp） in vivo. Methods： Ascite tumor xenografts were established by implanting human ovarian carcinoma cells SKOV3/AR intraperitoneally into the nude mice. The mice were randomized into the following three treatment groups with each group six mice respectively： Taxol, Taxol with lipofectamine and Taxol with siRNA/MDR1- lipofectamine intraperitoneal injection. The tumor growth rate and the ascite growth rate of mice were investigated. The expressions of MDR1 gene and P-gp in mice were determined by reverse transcription-polymerase chain reaction（RT-PCR） and immunohistochemistry respctively. Results： The growth of tumors and ascites in mice treated with Taxol and siRNA/MDR1- lipofectamine was significantly inhibited compared with those in mice of other groups. After 28 days＇ treatment, the average tumor weight and ascite volume decreased by 43.6% and 29.7% in the group treated with Taxol and siRNA/MDRl-lipofectamine compared with these treated with Taxol alone （P〈0.001）. The expressions of MDR1 gene and P-gp in the group treated with Taxol and siRNA/MDRl-lipofectamine were also decreased compared with those in the group treated with Taxol alone （P〈0.001）. Conclusion： Small interfering RNA targeting-MDR1 can effectively and specifically suppress the expression of MDRl（P-glycoprotein） and inhibit ovarian cancer growth in vivo.

关键词： RNA interference siRNA MDR1 gene Ovarian cancer Nude mice

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聚山梨酯80组分与其溶血性的关系

中国药科大学学报 2012年第3期43卷 231-235页

作者：李畅涂家生中国药科大学药剂学教研室南京210009

研究聚山梨酯80(Tween 80)的溶血不良反应与其成分的母体结构间的关系。Tween 80合成第一步中可能会产生3种相关母核结构:山梨醇、一失水山梨醇酐和二失水异山梨醇酐。经与油酸酯化、聚氧乙烯化后形成多成分混合物。本文通过质谱法以及... 详细信息

研究聚山梨酯80(Tween 80)的溶血不良反应与其成分的母体结构间的关系。Tween 80合成第一步中可能会产生3种相关母核结构:山梨醇、一失水山梨醇酐和二失水异山梨醇酐。经与油酸酯化、聚氧乙烯化后形成多成分混合物。本文通过质谱法以及溶血性考察对单一母核合成物山梨醇聚氧乙烯油酸酯(polyoxyethylene sorbitol oleate,POS)和异山梨醇酐聚氧乙烯油酸酯(polyoxyethylene isosorbide oleate,POI)进行了成分和溶血性比较。结果证明:山梨醇聚氧乙烯油酸酯具有极低的溶血不良反应,而异山梨醇酐聚氧乙烯油酸酯具有极高的溶血性。同时,萃取法进一步证明上述结果的正确性。

关键词：聚山梨酯80 溶血性山梨醇聚氧乙烯油酸酯异山梨醇酐聚氧乙烯油酸酯

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危机干预话语的论辩修辞机制

大连理工大学学报（社会科学版） 2014年第2期35卷 109-114页

作者：涂家金福建工程学院人文学院福建福州350108

危机干预话语是在个体或机构遭到质疑、批判而导致形象受损时所进行的驳斥与自我证当的修辞行动,是作为说服的最关键要素的修辞人格的修护,因而也必然具有论辩的维度。Perelman的论辩思想和古典修辞争议点理论可以在论辩基础、论辩施为... 详细信息

危机干预话语是在个体或机构遭到质疑、批判而导致形象受损时所进行的驳斥与自我证当的修辞行动,是作为说服的最关键要素的修辞人格的修护,因而也必然具有论辩的维度。Perelman的论辩思想和古典修辞争议点理论可以在论辩基础、论辩施为过程方面对危机干预和形象修护的话语机制作出更系统更合理的解释。由此整合而成的包含了推定层、争议层和技术层的危机干预话语模型也可用于指导修辞批评,因而具有理论和实践双重意义。危机干预话语的论辩修辞属性也表明了以或然性、情境性和受众性为基本特征的修辞理性在科学理性主导的社会的不可替代性。

关键词：修辞论辩危机修辞批评