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Novel indole and quinoline alkaloids from Melodinus yunnanensis

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Natural Products and Bioprospecting 2011年第1期1卷 25-28页

作者： Xiang-Hai CAI Yan li Jia SU Ya-Ping liU xiao-ning li xiao-Dong LUO State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China

6/7-Seco rearranged spiro-indolone alkaloids,meloyunines A(1)and B(2)and a monoterpenoid quinoline alkaloid meloyunine C(3)together with its possible intermediate 14,15-dehydromelohenine B(4),and their precursorΔ14-vincamenine(5)were isolated from Melodinus *** structures were elucidated based on NMR,FTIR,UV,and MS spectroscopic *** isolation of monoterpenoid indole,quinoline,and its immediate from the same plant chemically supported the biosynthesis of quinoline from *** 2 was cytotoxic against several human cancer cell lines.

关键词： spiro-indolone quinoline meloyunine Melodinus yunnanensis

Effects of the long wavelength-filtered continuousspectrum on natural refractive development in juvenile guinea pigs

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International Journal of Ophthalmology(English edition) 2019年第6期12卷 883-891页

作者： Rui-Qin li Wei-Zhong Lan xiao-ning li Hao-Ran Wu Qing-lin Xu Hong Zhong Wen-Tao li Zhi-Kuan Yang Aier School of Ophthalmology Central South UniversityChangsha 410015Hunan ProvinceChina Aier Institute of Optometry and Vision Science Changsha 410015Hunan ProvinceChina Huizhou Third People’s Hospital Guangzhou Medical UniversityHuizhou 516002Guangdong ProvinceChina

AIM: To investigate the effects of spectral composition and light intensity on natural refractive development in guinea ***: A total of 124 pigmented guinea pigs(2-week-old) were randomly assigned to three groups at high(Hi;4000 lx), medium(Me;400 lx) and low(Lo;50 lx) light intensities under a 12:12 light/dark cycle for 6 wk. Each group was subdivided into subgroups with the following spectra: broad spectrum Solux halogen light(BS), 600 nm above-filtered continuous spectrum(600F), 530 nm above-filtered continuous spectrum(530F), and 480 nm above-filtered continuous spectrum(480F;HiBS: n=10, Hi600F: n=10, Hi530F: n=10, Hi480F: n=10, MeBS: n=10, Me600F: n=10, Me530F: n=10, Me480F: n=10, LoBS: n=11, Lo600F: n=12, Lo530F: n=10, Lo480F: n=11). Refractive error, corneal curvature radius, and axial dimensions were determined by cycloplegic retinoscopy, photokeratometry, and A-scan ultrasonography before and after 2, 4, and 6 wk of treatment. Average changes from both eyes in the ocular parameters and refractive error were compared among different ***: After 6 wk of exposure, high-intensity lighting enhanced hyperopic shift;medium-and low-intensity lighting enhanced myopic shift(Plight intensity group than in the medium and high light intensity groups(HiBS: 0.65±0.02 mm, MeBS: 0.67±0.01 mm, LoBS:0.82±0.02 mm;Hi600 F: 0.64±0.02 mm, Me600F: 0.67±0.01 mm, Lo600F: 0.81±0.01 mm;Hi530F: 0.64±0.02 mm, Me530F: 0.67±0.01 mm, Lo530F: 0.73±0.02 mm;Hi480F: 0.64±0.01 mm, Me480F: 0.66±0.01 mm, Lo480F: 0.72±0.02 mm;Plighting, high light intensity rather than spectrum distributions that inhibits axial increase. Under medium-and low-intensity lighti

关键词： myopia wavelength spectral composition light intensity refractive development

Effect of Y_(2)O_(3) on microstructure and properties of CoCrFeNiTiNb high entropy alloy coating on Ti-6Al-4V surface by laser cladding

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Journal of Rare Earths 2024年第3期42卷 586-599,I0006页

作者： Zhen li Wei Zhao Kedong Yu ning Guo Guangchun xiao Zhiming Wang Hui Zhang College of Mechanical Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan250353China Shandong Institute of Mechanical Design and Research Jinan250031China

The effects of Y_(2)O_(3) on the microstructure, microhardness, wear resistance, high-temperature oxidation resistance, hot corrosion resistance, and electrochemical corrosion behaviour of CoCrFeNiTiNb high entropy alloy coatings formed on Ti-6Al-4V alloy surfaces were studied. The results show that the addition of Y_(2)O_(3) changes the proportion of the phase but does not change its type. The average grain size is only 1/4.7 of that of the high entropy alloy(HEA) coating, and the fine-grained strengthening leads to increases in the microhardness and wear resistance of 21.8% and 26.9%, respectively. The addition of Y_(2)O_(3) enhances the denseness and bonding properties of the oxide and corrosion product layers, reducing the oxidation and hot corrosion rates by 60.3% and 40.3%, respectively. The addition of Y_(2)O_(3) doubles the corrosion resistance which is attributed to the refinement of the grains, the increased proportion of HCP and TiN, and the weakening of galvanic coupling corrosion.

关键词： Laser cladding High entropy alloy coatings Rare earths Wear properties High temperature properties Electrochemical corrosion

An Improved Modulation Strategy for Single-phase Three-level Neutral-point-clamped Converter in Critical Conduction Mode

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 981-990页

作者： ning li Yujie Cao xiaokang liu Yan Zhang Ruotong Wang lin Jiang xiao-Ping Zhang School of Electrical Engineering Xi’an University of TechnologyXi’anChina the Department of Electronics Information and BioengineeringPolitecnico di MilanoMilanItaly Xi’an Jiaotong University Xi’anChina the Department of Electrical Engineering and Electronics University of LiverpoolLiverpoolU.K. the Department of Electronic Electrical and Systems EngineeringUniversity of BirminghamBirminghamU.K.

Two-level totem-pole power factor correction(PFC)converters in critical conduction mode(CRM)suffer from the wide regulation range of switching ***,in highfrequency applications,the number of switching times increases,resulting in significant switching *** solve these issues,this paper proposes an improved modulation strategy for the single-phase three-level neutral-point-clamped(NPC)converter in CRM with *** optimizing the discharging strategy and switching state sequence,the switching frequency and its variation range have been efficiently *** detailed performance analysis is also presented regarding the switching frequency,the average switching times,and the effect of voltage gain.A 2 k W prototype is built to verify the effectiveness of the proposed modulation strategy and analysis *** with the totem-pole PFC converter,the switching frequency regulation range of the three-level PFC converter is reduced by 36.48%and the average switching times is reduced by 45.10%.The experimental result also shows a 1.2%higher efficiency for the three-level PFC converter in the full load range.

关键词： Critical conduction mode(CRM) on-board charger switching frequency range switching times power factor correction(PFC) three-level converter

Graph-decomposed k-NN searching algorithm on road network

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Frontiers of Computer Science 2024年第3期18卷 243-245页

作者： Wei JIANG Bo ning Guanyu li Mei BAI xiao JIA Fangliang WEI Faculty of Information Science and Technology Dalian Maritime UniversityDalian 116026China Jiangxing Intelligence Inc. Shenzhen 518100China

1 Introduction The k-NN(k Nearest Neighbors)searching problem on road network constitutes a crucial aspect of location-oriented services,which has boasted the practical implications.

关键词： services searching network

Autonomous Recommendation of Fault Detection Algorithms for Spacecraft

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IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 273-275页

作者： Wenbo li Baoling ning the National Key Laboratory of Science and Technology on Space Intelligent Control Beijing Institute of Control EngineeringBeijing 100094China the School of Data Science and Technology Heilongjiang UniversityHarbin 150001China

Dear Editor, This letter deals with the problem of algorithm recommendation for online fault detection of spacecraft. By transforming the time series data into distributions and introducing a distribution-aware measure, a principal method is designed for quantifying the detectabilities of fault detection algorithms over special datasets.

关键词： fault introducing letter

Performance enhancement of perovskite solar cells:surface is the key

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Science China Materials 2024年第1期67卷 375-376页

作者： Wenzhuo li Zhijun ning School of Physical Science and Technology Shanghaitech UniversityShanghai 201210China

Metal halide perovskite solar cells(PSCs)stand out as one of the most promising contenders among photovoltaic technologies for the *** the past decade,PSCs with high power conversion efficiency(PCE)predominantly adopted the normal(ni-p)device ***,a common p-type organic small molecule,Spiro-OMe TAD,which is widely employed at the top layer of n-i-p devices[1],faces issues such as susceptibility to water absorption and poor thermal stability.

关键词： structure stability perovskite

Subchronic Toxicity Study on Soy Isoflavones in Rats

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Biomedical and Environmental Sciences 2009年第3期22卷 259-264页

作者： WEN-ZHONG ZHANG WEN-MING CUI XIN ZHANG WEI WANG XU-DONG JIA xiao-PENG ZHANG ning li Institute of Nutrition and Food Safety Chinese Center for Disease Control and Prevention Beijing 100021 China

Objective To investigate the subchronic toxicity of soy isoflavones （SIF） in male rats. Method Fifty Sprague-Dawley rats were randomly divided into 5 groups, 10 rats per group. SIF were given to rats in different groups by gavage at dose of 0, 0.2, 0.5, 1.5, and 4.5 g/kg bw, respectively for 13 weeks. Clinical manifestations, body weight, and food consumption were observed weekly. At the end of the study, urinalysis, hematology, clinical chemistry, total testosterone, and follicle-stimulating hormone were tested, and histopathological examinations were performed. Results No mortality, ophthalmic abnormalities or treatment-related clinical signs were identified during the study. As compared with the control group, significantly lower body weights and food consumption were observed in 1.5 and 4.5 g/kg bw groups. In clinical chemistry tests, triglyceride was significantly decreased and high-density lipoprotein cholesterol was significantly increased in all SIF-treated groups. Total testosterone levels were significantly lower in 0.50, 1.50, and 4.5 g/kg bw dose groups than in the control group. Microscopic examination showed that the mammary glands exhibited hyperplasia and excreted latex in rats of the 4.5 g/kg bw group. No changes attributable to treatment of SIF in other parameters were found. Conclusion SIF at high dosages caused significant endocrine disruption in male rats. The no observed adverse effect level （NOAEL） of SIF to male rats in this study is considered to be 0.20 g/kg bw.

关键词： Soy isoflavone Rat Subchronic toxicity

Impact of non-ideal UE hardware on cell-free massive MIMO network with centralized operation

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Science China(Information Sciences) 2024年第4期67卷 255-271页

作者： ning li Pingzhi FAN Institute of Mobile Communications Southwest Jiaotong University

This paper investigates the impact of non-ideal user equipment(UE) hardware on a cell-free(CF) massive MIMO(mMIMO) network with centralized operation under spatially correlated channels. The minimum mean-squared error(MMSE) estimator can be derived with the help of the generic non-ideal UE hardware model. It is demonstrated that even if the effective signal-to-noise ratio approaches infinity, pilot contamination and imperfect hardware can cause a non-zero estimation error floor. After that, a lower bound is determined for the ergodic uplink capacity of the centralized CF mMIMO network under non-ideal UE hardware. Moreover, the optimal receive combining vector is obtained to maximize the uplink spectral efficiency(SE). The maximum ratio(MR) and regularized zero-forcing(RZF) combining schemes are offered as alternatives in light of the computational complexity of the MMSE receiver. Comparing the RZF to the MMSE scheme under different levels of hardware impairments, our findings indicate that the RZF receiver suffers a negligible loss in total SE. For MR combining, a novel closed-form uplink achievable SE expression is obtained based on the MMSE estimator and the use-and-then-forget bounding technique. This expression gives vital insights into the achievable uplink performance with UE hardware impairments. Besides, for various hardware impairment factors, the impact of pilot sequence length on average sum SE is disclosed for different receive combining schemes. To increase the overall SE of the max-min fairness scheme, a heuristic fractional power control scheme with UE hardware impairments is developed, which can essentially avoid sacrificing the SE of other UEs while maximizing the SE of the unluckiest UE in the whole network. Finally,our theoretical performance analysis and power control algorithm are validated by simulation results, and fundamental design guidelines are provided for selecting hardware satisfying the practical UE requirements.

关键词： cell-free massive MIMO centralized operation spatially correlated channels hardware impairments channel estimation uplink spectral efficiency optimal receive combining pilot length design fractional power control