With the development of space technology,it is possible to build a space station in Earth-Moon space as a transit for Earth-Moon round-trip and entering in the deep space.Rendezvous and docking is one of the key techn...With the development of space technology,it is possible to build a space station in Earth-Moon space as a transit for Earth-Moon round-trip and entering in the deep space.Rendezvous and docking is one of the key technologies for building an Earth-Moon space station.A guidance strategy for rendezvous and docking from the Earth orbit to the space station in the Earth-Moon NRHO orbit is proposed in this paper,which is suitable for engineering applications.Firstly,the rendezvous and docking process is divided into three sections,i.e.,the large-range orbit transfer section,far-range guidance section,and close-range approaching section.The suitable terminal of large-range orbit transfer is selected according to the eigenvalue of NRHO orbit state transition matrix.The two-impulse guidance method based on the relative motion equation in the three-body problem is adopted for the far-range guidance section.The impulse time and amplitude are solved with the optimization algorithm.The linear constant three-body relative motion equation is proposed for the close-range approaching section,and the rendezvous and docking is completed by a two-stage linear approximation.Finally,a simulation analysis is carried out,and the simulation results show that the adopted dynamics equations and the designed guidance law are effective,and the three flight phases are naturally connected to accomplish the rendezvous and docking mission from the Earth orbit to the space station on the Earth-Moon NRHO.展开更多
A spacecraft attitude estimation method based on electromagnetic vector sensors(EMVS)array is proposed,which employs the orthogonally constrained parallel factor(PARAFAC)algorithm and makes use of measurements of the ...A spacecraft attitude estimation method based on electromagnetic vector sensors(EMVS)array is proposed,which employs the orthogonally constrained parallel factor(PARAFAC)algorithm and makes use of measurements of the two-dimensional direction-of-arrival(2D-DOA)and polarization angles,aiming to address the issues of incomplete,asynchronous,and inaccurate third-party reference used for attitude estimation in spacecraft docking missions by employing the electromagnetic wave’s three-dimensional(3D)wave structure as a complete third-party reference.Comparative analysis with state-ofthe-art algorithms shows significant improvements in estimation accuracy and computational efficiency with this algorithm.Numerical simulations have verified the effectiveness and superiority of this method.A high-precision,reliable,and cost-effective method for rapid spacecraft attitude estimation is provided in this paper.展开更多
In search of natural renewable resource-based bioactive molecules,20 hydroxamate inhibitors were designed and synthesized using cinamaldehyde as the starting material.Their structures were characterized by FT-IR,^(1)H...In search of natural renewable resource-based bioactive molecules,20 hydroxamate inhibitors were designed and synthesized using cinamaldehyde as the starting material.Their structures were characterized by FT-IR,^(1)HNMR,^(13)C NMR,and HRMS.And in vitro antifungal activity of the target compounds against 8 tested fungi was preliminarily evaluated by the agar dilution method.The bioassay results revealed that at the concentration of 50 mg/L,the target compounds exhibited certain inhibitory activity against 8 tested fungi,in which compounds 5r(R=o,o-Cl),5c(R=m-F),5b(R=o-F)and 5p(R=o,p-Cl)displayed better inhibitory activity of 93.3%,76.8%,75.3%and 72.3%,respectively,against P.piricola than that of the positive control chlorothalonil.At the same time,3D-quantitative structure-activity relationship(3D-QSAR)study was carried out to explore the relationship of the molecular structures with their antifungal activity against P.piricola.And a reasonable and effective 3D-QSAR model(r^(2)=0.980,q^(2)=0.501)has been established.Besides,molecular docking was also performed to reveal the binding mode of the target compound 5r(R=o,o-Cl)with succinate dehydrogenase(SDH).It was found that compound 5r could be well embedded in the active pocket of the receptor protein.This showed a similar mode with SDH inhibitors(SDHI)carboxin.展开更多
中药不论在直接抑制肿瘤生长,还是辅助西医治疗肿瘤方面都发挥着不容忽视的作用.本文经检索中国知网、万方、维普、Pubmed、Web of Science等数据库,纳入中药汤剂联合化疗治疗非小细胞肺癌(NSCLC)的随机对照试验,通过Meta、用药规律、...中药不论在直接抑制肿瘤生长,还是辅助西医治疗肿瘤方面都发挥着不容忽视的作用.本文经检索中国知网、万方、维普、Pubmed、Web of Science等数据库,纳入中药汤剂联合化疗治疗非小细胞肺癌(NSCLC)的随机对照试验,通过Meta、用药规律、网络药理学和细胞实验等分析方法系统评价中药联合化疗治疗NSCLC的疗效、安全性及作用机制,最终纳入56篇文献进行统计分析,共4992例患者、57首处方、172味中药.结果显示,中药联合化疗治疗组的1年生存率、肝功能损伤、总有效率、胃肠道不良反应等方面均优于单纯化疗组.用药频次>20的有7味:药味以甘苦为主,药性以寒温为主,主要归为肺经和肝经.得到5个高频药物聚类,关联规则分析得到置信度最高的4条药物组合为:天花粉-麦冬、玉竹-麦冬、北沙参-玉竹-麦冬、白术-黄芪-党参.收集到核心中药成分潜在作用靶点与NSCLC交集靶点126个;PPI分析得到3个核心靶点:AKT1、EGFR、SRC;KEGG分析表明关键通路为PI3K-Akt信号通路;筛选得到3个关键成分:木犀草素、槲皮素、山柰酚;分子对接结果表明关键成分和核心靶点均能稳定结合.细胞实验结果表明,木犀草素可有效抑制A549细胞的增殖、活力和迁移,诱导其发生凋亡,并使其形态发生变化.本文结果表明,中药联合化疗治疗NSCLC可以提高其临床疗效、降低化疗的毒副作用;黄芪、麦冬、党参、北沙参等核心中药多种成分可通过多靶点、多途径协同治疗NSCLC;关键中药的核心成分木犀草素可抑制A549细胞的增殖、活力和迁移,并可诱导其发生凋亡.展开更多
基金National Natural Science Foundation of China(U20B2054)。
文摘With the development of space technology,it is possible to build a space station in Earth-Moon space as a transit for Earth-Moon round-trip and entering in the deep space.Rendezvous and docking is one of the key technologies for building an Earth-Moon space station.A guidance strategy for rendezvous and docking from the Earth orbit to the space station in the Earth-Moon NRHO orbit is proposed in this paper,which is suitable for engineering applications.Firstly,the rendezvous and docking process is divided into three sections,i.e.,the large-range orbit transfer section,far-range guidance section,and close-range approaching section.The suitable terminal of large-range orbit transfer is selected according to the eigenvalue of NRHO orbit state transition matrix.The two-impulse guidance method based on the relative motion equation in the three-body problem is adopted for the far-range guidance section.The impulse time and amplitude are solved with the optimization algorithm.The linear constant three-body relative motion equation is proposed for the close-range approaching section,and the rendezvous and docking is completed by a two-stage linear approximation.Finally,a simulation analysis is carried out,and the simulation results show that the adopted dynamics equations and the designed guidance law are effective,and the three flight phases are naturally connected to accomplish the rendezvous and docking mission from the Earth orbit to the space station on the Earth-Moon NRHO.
文摘A spacecraft attitude estimation method based on electromagnetic vector sensors(EMVS)array is proposed,which employs the orthogonally constrained parallel factor(PARAFAC)algorithm and makes use of measurements of the two-dimensional direction-of-arrival(2D-DOA)and polarization angles,aiming to address the issues of incomplete,asynchronous,and inaccurate third-party reference used for attitude estimation in spacecraft docking missions by employing the electromagnetic wave’s three-dimensional(3D)wave structure as a complete third-party reference.Comparative analysis with state-ofthe-art algorithms shows significant improvements in estimation accuracy and computational efficiency with this algorithm.Numerical simulations have verified the effectiveness and superiority of this method.A high-precision,reliable,and cost-effective method for rapid spacecraft attitude estimation is provided in this paper.
文摘In search of natural renewable resource-based bioactive molecules,20 hydroxamate inhibitors were designed and synthesized using cinamaldehyde as the starting material.Their structures were characterized by FT-IR,^(1)HNMR,^(13)C NMR,and HRMS.And in vitro antifungal activity of the target compounds against 8 tested fungi was preliminarily evaluated by the agar dilution method.The bioassay results revealed that at the concentration of 50 mg/L,the target compounds exhibited certain inhibitory activity against 8 tested fungi,in which compounds 5r(R=o,o-Cl),5c(R=m-F),5b(R=o-F)and 5p(R=o,p-Cl)displayed better inhibitory activity of 93.3%,76.8%,75.3%and 72.3%,respectively,against P.piricola than that of the positive control chlorothalonil.At the same time,3D-quantitative structure-activity relationship(3D-QSAR)study was carried out to explore the relationship of the molecular structures with their antifungal activity against P.piricola.And a reasonable and effective 3D-QSAR model(r^(2)=0.980,q^(2)=0.501)has been established.Besides,molecular docking was also performed to reveal the binding mode of the target compound 5r(R=o,o-Cl)with succinate dehydrogenase(SDH).It was found that compound 5r could be well embedded in the active pocket of the receptor protein.This showed a similar mode with SDH inhibitors(SDHI)carboxin.
文摘中药不论在直接抑制肿瘤生长,还是辅助西医治疗肿瘤方面都发挥着不容忽视的作用.本文经检索中国知网、万方、维普、Pubmed、Web of Science等数据库,纳入中药汤剂联合化疗治疗非小细胞肺癌(NSCLC)的随机对照试验,通过Meta、用药规律、网络药理学和细胞实验等分析方法系统评价中药联合化疗治疗NSCLC的疗效、安全性及作用机制,最终纳入56篇文献进行统计分析,共4992例患者、57首处方、172味中药.结果显示,中药联合化疗治疗组的1年生存率、肝功能损伤、总有效率、胃肠道不良反应等方面均优于单纯化疗组.用药频次>20的有7味:药味以甘苦为主,药性以寒温为主,主要归为肺经和肝经.得到5个高频药物聚类,关联规则分析得到置信度最高的4条药物组合为:天花粉-麦冬、玉竹-麦冬、北沙参-玉竹-麦冬、白术-黄芪-党参.收集到核心中药成分潜在作用靶点与NSCLC交集靶点126个;PPI分析得到3个核心靶点:AKT1、EGFR、SRC;KEGG分析表明关键通路为PI3K-Akt信号通路;筛选得到3个关键成分:木犀草素、槲皮素、山柰酚;分子对接结果表明关键成分和核心靶点均能稳定结合.细胞实验结果表明,木犀草素可有效抑制A549细胞的增殖、活力和迁移,诱导其发生凋亡,并使其形态发生变化.本文结果表明,中药联合化疗治疗NSCLC可以提高其临床疗效、降低化疗的毒副作用;黄芪、麦冬、党参、北沙参等核心中药多种成分可通过多靶点、多途径协同治疗NSCLC;关键中药的核心成分木犀草素可抑制A549细胞的增殖、活力和迁移,并可诱导其发生凋亡.
