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| Articles
by
Shuang Li |
Total Records (
4 ) for
Shuang Li |
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Shuang Li
,
Yuming Peng
,
Yuping Lu
,
Liu Zhang
and
Yufei Liu
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Pin-point landing is considered as a key technology for future manned Mars landing and Mars base missions. The traditional inertial navigation system (INS) based guidance, navigation and control (GNC) mode used in the Mars entry, descent and landing (EDL) phase has no ability to achieve the precise and safe Mars landing, so novel EDL GNC methodologies should be investigated to meet this goal. This paper proposes the MCAV/IMU integrated navigation scheme for the powered descent phase of Mars EDL. The Miniature Coherent Altimeter and Velocimeter (MCAV) is adopted to correct the inertial bias and drift and improve the performance of integrated navigation. Altitude and velocity information derived from MCAV and the lander’s state information sensed by inertial measurement unit (IMU) are integrated in extended Kalman filter algorithm. The validity of the proposed navigation scheme is confirmed by computer simulation. |
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Xia Hu
,
Min Zhou
and
Shuang Li
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As is growing interest in the conduct of business transactions
by electronic means through the Internet and dedicated networks this is often
referred to as Electronic Commerce (EC). This paper reviews developments in
electronic commerce with a particular focus on its applicability and uptake
within the construction industry. Electronic commerce business models are reviewed
and the enablers and barriers to their uptake in the construction sector presented.
Therefore this paper concludes with future trends in electronic commerce and
the need for construction organizations to make the necessary investments that
will enable them to take advantage of these and further aiming to contributing
in solving this problem by applying automated safety rule checking to enterprise
information construction and countermeasure research under the environment of
electronic commerce. |
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Qi Zhao
,
Shuang Li
,
Fei Xue
,
Yilong Zou
,
Cheng Chen
,
Mark Bartlam
and
Zihe Rao
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The newly emergent human coronavirus HKU1 (HCoV-HKU1) was first identified in Hong Kong in 2005. Infection by HCoV-HKU1 occurs worldwide and causes syndromes such as the common cold, bronchitis, and pneumonia. The CoV main protease (Mpro), which is a key enzyme in viral replication via the proteolytic processing of the replicase polyproteins, has been recognized as an attractive target for rational drug design. In this study, we report the structure of HCoV-HKU1 Mpro in complex with a Michael acceptor, inhibitor N3. The structure of HCoV-HKU1 provides a high-quality model for group 2A CoVs, which are distinct from group 2B CoVs such as severe acute respiratory syndrome CoV. The structure, together with activity assays, supports the relative conservation at the P1 position that was discovered by sequencing the HCoV-HKU1 genome. Combined with structural data from other CoV Mpros, the HCoV-HKU1 Mpro structure reported here provides insights into both substrate preference and the design of antivirals targeting CoVs. |
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Yourong Ye
,
Jie Sun
,
Shuang Li
,
Zongsheng Zhao
,
Daquan Li
and
Jinfu Wang
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Researchers investigated the effects of Estrogen (E2) and Progesterone (P4) on the morphology,
growth and proliferation of chicken endometrial cells in vitro. Type I collagenase digestion was used to isolate
endometrial epithelial and stromal cells and the cells were identified by immunohistochemistry. MTT assays
(MTT, [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide]) were performed to analyze the effects
of the sex hormones on the proliferation of the endometrial cells in vitro and growth curves were constructed
to demonstrate the growth rules of endometrial cells cultured in vitro. The epithelial and stromal cells tested
positive for keratin CK18 and vimentin, respectively, in the immunohistochemical analysis. The MTT
experiments showed that the growth rate of the chicken endometrial cells began to increase logarithmically on
day 2, reaching the plateau phase on day 6 or 7. The endometrial epithelial cells treated with 100 nM E2 and/or
100 nM P4 proliferated at a significantly higher rate p<0.05) than the control cells. However, although, the
stromal cells treated with 100 nM P4 proliferated at a significantly higher rate (p<0.05) than the control cells,
the E2-treated endometrial stromal cells did not. |
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