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枸杞茶醋醋酸发酵工艺优化及抗氧化活性研究
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作者 强晓 张紫瑗 +3 位作者 耿贝贝 李天萌 袁宇轩 夏婷 《中国酿造》 CAS 北大核心 2024年第3期151-156,共6页
该研究以枸杞芽茶和玉米须为原料,采用巴氏醋杆菌(Acetobacter pasteurianus)AC-2005发酵制备枸杞茶醋,以总酸含量为评价指标,通过单因素试验及正交试验优化枸杞茶醋醋酸发酵工艺,对其理化指标进行测定,并对其发酵前后的功能活性成分和... 该研究以枸杞芽茶和玉米须为原料,采用巴氏醋杆菌(Acetobacter pasteurianus)AC-2005发酵制备枸杞茶醋,以总酸含量为评价指标,通过单因素试验及正交试验优化枸杞茶醋醋酸发酵工艺,对其理化指标进行测定,并对其发酵前后的功能活性成分和抗氧化活性变化进行分析。结果表明,枸杞茶醋的最优醋酸发酵工艺为初始酒精度9%vol,巴氏醋杆菌AC-2005接种量10%,发酵温度30℃,初始pH值3.5。在此优化条件下,枸杞茶醋的总酸含量为7.10 g/100 mL,pH值为3.56,还原糖含量为1.70 g/100 mL,可溶性固形物含量为9.28 g/100 mL,其理化指标符合相关标准要求。与发酵前相比,枸杞茶醋中的总酚(2.27 mg/mL)和总黄酮含量(0.94 mg/mL)显著升高(P<0.05),甜菜碱含量(2.30 mg/mL)无显著变化(P>0.05),类胡萝卜素含量(0.62 mg/mL)显著降低(P<0.05);抗氧化能力显著升高(P<0.05),1,1-二苯基-2-三硝基苯肼(DPPH)、2,2’-联氮-双-3-乙基苯并噻唑啉-6-磺酸(ABTS)自由基清除率和铁离子还原/抗氧化能力(FRAP)分别为20.27%、12.71%和11.68%。 展开更多
关键词 枸杞茶醋 醋酸发酵 工艺优化 功能活性成分 抗氧化活性
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Multi-Objective Optimization of Aluminum Alloy Electric Bus Frame Connectors for Enhanced Durability
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作者 Wenjun Zhou Mingzhi Yang +3 位作者 Qian Peng Yong Peng Kui Wang qiang xiao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第7期735-755,共21页
The widespread adoption of aluminumalloy electric buses,known for their energy efficiency and eco-friendliness,faces a challenge due to the aluminum frame’s susceptibility to deformation compared to steel.This issue ... The widespread adoption of aluminumalloy electric buses,known for their energy efficiency and eco-friendliness,faces a challenge due to the aluminum frame’s susceptibility to deformation compared to steel.This issue is further exacerbated by the stringent requirements imposed by the flammability and explosiveness of batteries,necessitating robust frame protection.Our study aims to optimize the connectors of aluminum alloy bus frames,emphasizing durability,energy efficiency,and safety.This research delves into Multi-Objective Coordinated Optimization(MCO)techniques for lightweight design in aluminum alloy bus body connectors.Our goal is to enhance lightweighting,reinforce energy absorption,and improve deformation resistance in connector components.Three typical aluminum alloy connectors were selected and a design optimization platform was built for their MCO using a variety of software and methods.Firstly,through three-point bending experiments and finite element analysis on three types of connector components,we identified optimized design parameters based on deformation patterns.Then,employing Optimal Latin hypercube design(OLHD),parametric modeling,and neural network approximation,we developed high-precision approximate models for the design parameters of each connector component,targeting energy absorption,mass,and logarithmic strain.Lastly,utilizing the Archive-based Micro Genetic Algorithm(AMGA),Multi-Objective Particle Swarm Optimization(MOPSO),and Non-dominated SortingGenetic Algorithm(NSGA2),we explored optimized design solutions for these joint components.Subsequently,we simulated joint assembly buckling during bus rollover crash scenarios to verify and analyze the optimized solutions in three-point bending simulations.Each joint component showcased a remarkable 30%–40%mass reduction while boosting energy absorption.Our design optimization method exhibits high efficiency and costeffectiveness.Leveraging contemporary automation technology,the design optimization platform developed in this study is poised to facilitate intelligent optimization of lightweight metal components in future applications. 展开更多
关键词 Aluminum connectors three-point bending simulation parametric design model multi-objective collaborative optimization
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枸杞果醋饮料的配方优化及品质分析 被引量:10
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作者 王怡明 夏婷 +6 位作者 强晓 耿贝贝 李少鹏 郑宇 乔长晟 岳思君 王敏 《中国酿造》 CAS 北大核心 2022年第8期190-194,共5页
以枸杞为原料制备枸杞汁、枸杞醋,并添加白砂糖及菊花提取液制备枸杞果醋饮料,通过单因素试验及正交试验优化枸杞果醋饮料配方,并对其感官、理化及微生物指标进行分析。结果表明,枸杞果醋饮料的最佳配方为:枸杞醋8%,枸杞汁15%,白砂糖6%... 以枸杞为原料制备枸杞汁、枸杞醋,并添加白砂糖及菊花提取液制备枸杞果醋饮料,通过单因素试验及正交试验优化枸杞果醋饮料配方,并对其感官、理化及微生物指标进行分析。结果表明,枸杞果醋饮料的最佳配方为:枸杞醋8%,枸杞汁15%,白砂糖6%,菊花提取液15%。在最优配方条件下,枸杞果醋饮料感官评分为95.47分,枸杞果醋饮料口感柔和、酸甜爽口。总酸、不挥发酸及氨基酸态氮含量分别为0.66 g/100 m L、0.36 g/100 m L、0.07 g/100 m L,总糖、蛋白质、脂肪含量分别为9.62 g/100 m L、0.48 g/100 m L、0.06 g/100 m L,其理化及微生物指标均符合国家农业部标准NY/T 2987—2016《绿色食品果醋饮料》要求。 展开更多
关键词 枸杞 果醋饮料 配方优化 品质分析
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AECOPD患者T淋巴细胞与肺功能及炎症指标的相关性研究 被引量:3
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作者 董素素 梅牧 +4 位作者 王天立 谭亚芬 肖强 张旋 李秋平 《数理医药学杂志》 CAS 2023年第7期543-548,共6页
目的 探讨慢性阻塞性肺疾病急性加重期(acute exacerbation of chronic obstructive pulmonary disease,AECOPD)患者T淋巴细胞亚群与肺功能、超敏C反应蛋白(C-reactive protein,CRP)、一年急性加重次数的关系。方法 对66例AECOPD老年患... 目的 探讨慢性阻塞性肺疾病急性加重期(acute exacerbation of chronic obstructive pulmonary disease,AECOPD)患者T淋巴细胞亚群与肺功能、超敏C反应蛋白(C-reactive protein,CRP)、一年急性加重次数的关系。方法 对66例AECOPD老年患者和63例健康老年人的资料进行分析,比较超敏CRP、总T淋巴细胞数目(CD3)、辅助性T淋巴细胞(CD4)、杀伤性T淋巴细胞(CD8)及辅助与杀伤细胞比值(CD4/CD8)的差异。将AECOPD患者按慢性阻塞性肺疾病全球倡议(Global Initiative for Chronic Obstructive Lung Disease,GOLD)分级分为I—Ⅱ级组和Ⅲ—Ⅳ级组,比较不同组CD3、CD4、CD8、CD4/CD8、超敏CRP的差异。分析CD3、CD4、CD8、CD4/CD8与FEV1%pred、FEV1/FVC、超敏CRP、一年急性加重次数的相关性。结果 AECOPD组和健康对照组的体重指数、FEV1%pred、CD3、CD4、CD8、CD4/CD8、超敏CRP差异均有显著性(P <0.05);Ⅰ—Ⅱ级组、Ⅲ—Ⅳ级组的CD3、CD4、CD4/CD8、超敏CRP水平不同(P <0.05);CD3、CD4、CD4/CD8与FEV1%pred、FEV1/FVC呈正相关,与超敏CRP、急性加重次数呈负相关(P <0.05)。结论 AECOPD患者外周血CD3、CD4、CD4/CD8与肺功能、急性加重次数存在相关性,T淋巴细胞亚群或可作为判断COPD患者预后的指标。 展开更多
关键词 T淋巴细胞 肺功能 慢性阻塞性肺疾病急性加重期 超敏C反应蛋白 炎症指标
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转录组学技术在急性白血病诊治中的应用研究进展 被引量:1
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作者 强晓 耿贝贝 +1 位作者 刘四喜 夏婷 《实用医学杂志》 CAS 北大核心 2023年第22期3010-3014,共5页
近年来转录组学技术飞速发展,利用该技术对急性白血病(acute leukemia,AL)的转录组进行分析,能够客观准确地检测AL细胞中的异常基因和功能变化,对深入揭示AL发生发展的分子机制具有重要意义。RNA测序(RNA-sequencing,RNA-seq)技术即转... 近年来转录组学技术飞速发展,利用该技术对急性白血病(acute leukemia,AL)的转录组进行分析,能够客观准确地检测AL细胞中的异常基因和功能变化,对深入揭示AL发生发展的分子机制具有重要意义。RNA测序(RNA-sequencing,RNA-seq)技术即转录组测序技术,不仅能够识别出新的致癌基因融合和特征分子标志物,对AL进行更准确的分类和风险评估,还可以针对识别出的异常基因或细胞亚群,采用对应的靶向治疗方案以改善AL患者的预后。此外,转录组学技术与其他组学技术联用,能够从不同层次监测AL的多元组学变化,更全面地解析AL发生发展的分子机制。随着RNA-seq技术的不断应用,将为AL治疗提供新的精准靶点和临床策略。 展开更多
关键词 转录组学 急性白血病 RNA测序技术 基因融合
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Reversal of multidrug resistance in gastric cancer cells by CDX2 downregulation 被引量:10
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作者 Lin-Hai Yan xiao-Tong Wang +6 位作者 Jie Yang Chao Lian Fan-Biao Kong Wei-Yuan Wei Wen Luo qiang xiao Yu-Bo Xie 《World Journal of Gastroenterology》 SCIE CAS 2013年第26期4155-4165,共11页
AIM: To explore the role of CDX2 in the multi-drug resistance (MDR) process of gastric cancer in vitro and in vivo . METHODS: A cisplatin-resistant gastric cancer cell line with stable downregulation of CDX2 was estab... AIM: To explore the role of CDX2 in the multi-drug resistance (MDR) process of gastric cancer in vitro and in vivo . METHODS: A cisplatin-resistant gastric cancer cell line with stable downregulation of CDX2 was established. mRNA and protein expression levels of CDX2, survivin, cyclin D1, and c-Myc were detected by western blotting and semi-quantitative reverse-transcriptase polymerase chain reaction (RT-PCR). The influence of downregulation of CDX2 on MDR was assessed by measuring IC50 of SGC7901/DDP cells to cisplatin, doxorubicin, and 5-fluorouracil, rate of doxorubicin efflux, apoptosis, and cell cycle progression detected by flow cytometry. In addition, we determined the in vivo effects of CDX2 small interfering RNA (siRNA) on tumor size, and apoptotic cells in tumor tissues were detected by deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling and hematoxylin and eosin staining. RESULTS: CDX2 siRNA led to downregulation of endogenous CDX2 mRNA (0.31 ± 0.05 vs 1.10 ± 0.51, 0.31 ± 0.05 vs 1.05 ± 0.21, P = 0.003) and protein (0.12 ± 0.08 vs 0.51 ± 0.07, 0.12 ± 0.08 vs 0.55 ± 0.16, P = 2.57 × 10 -4) expression. It significantly promoted the sensitivity of SGC7901/DDP cells to cisplatin (0.12 ± 0.05 vs 0.33 ± 0.08, 0.12 ± 0.05 vs 0.39 ± 0.15, P = 0.001), doxorubicin (0.52 ± 0.13 vs 4.11 ± 1.25, 0.52 ± 0.13 vs 4.05 ± 1.44, P = 2.81 × 10-4), and 5-fluorouracil (0.82 ± 0.13 vs 2.81 ± 0.51, 0.82 ± 0.13 vs 3.28 ± 1.03, P = 1.71 × 10-4). Flow cytometry confirmed that the percentage of apoptotic cells increased after CDX2 downregulation (32.15% ± 2.15% vs 17.63% ± 3.16%, 32.15% ± 2.15% vs 19.3% ± 2.25%, P = 1.73 × 10-6). This notion was further supported by the observation that downregulation of CDX2 blocked entry into the S-phase of the cell cycle (31.53% ± 3.78% vs 65.05% ± 7.25%, 31.53% ± 3.78% vs 62.27% ± 5.02%, P = 7.55 × 10-7). Furthermore, downregulation of CDX2 significantly increased intracellular accumulation of doxorubicin (0.21 ± 0.06 vs 0.41 ± 0.11, 0.21 ± 0.06 vs 0.40 ± 0.08, P = 0.003). In molecular studies, semiquantitative RT-PCR and western blotting revealed that CDX2 downregulation could inhibit expression of c-Myc, survivin and cyclin D1. CONCLUSION: CDX2 may be involved in regulating multiple signaling pathways in reversing MDR, suggesting that CDX2 may represent a novel target for gastric cancer therapy. 展开更多
关键词 HOMEOBOX gene CDX2 RNA interference Gastric cancer Drug resistance Murine model
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E2F-1 overexpression inhibits human gastric cancer MGC-803 cell growth in vivo 被引量:10
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作者 Wei-Yuan Wei Lin-Hai Yan +7 位作者 xiao-Tong Wang Lei Li Wen-Long Cao xiao-Shi Zhang Ze-Xu Zhan Han Yu Yu-Bo Xie qiang xiao 《World Journal of Gastroenterology》 SCIE CAS 2015年第2期491-501,共11页
AIM: To evaluate the influence of E2F-1 on the growth of human gastric cancer(GC) cells in vivo and the mechanism involved. METHODS: E2F-1 recombinant lentiviral vectors were injected into xenograft tumors of MGC-803 ... AIM: To evaluate the influence of E2F-1 on the growth of human gastric cancer(GC) cells in vivo and the mechanism involved. METHODS: E2F-1 recombinant lentiviral vectors were injected into xenograft tumors of MGC-803 cells in nude mice, and then tumor growth was investigated. Overexpression of transcription factor E2F-1 was assessed by reverse transcription-polymerase chain reaction(RT-PCR) and Western blotting analysis. Apoptosis rates were determined using a terminal deoxynucleotidyl transferase-mediated d UTP-biotin nick end labeling(TUNEL) assay. Expression levels of certain cell cycle regulators and apoptosis-related proteins, such as Bax, survivin, Bcl-2, cyclin D1, S-phase kinaseassociated protein 2, and c-Myc were examined by Western blotting and RT-PCR. RESULTS: Xenograft tumors of MGC-803 cells in nude mice injected with E2F-1 recombinant lentiviral vectors stably overexpressed the E2F-1 gene as measured by semi-quantitative RT-PCR(relative m RNA expression: 0.10 ± 0.02 vs 0.05 ± 0.02 for control vector and 0.06 ± 0.03 for no infection; both P < 0.01) and Western blotting(relative protein expression: 1.90 ± 0.05 vs 1.10 ± 0.03 in control vector infected and 1.11 ± 0.02 for no infection; both P < 0.01). The growth-curve of tumor volumes revealed that infection with E2F-1 recombinant lentiviral vectors significantly inhibited the growth of human GC xenografts(2.81 ± 1.02 vs 6.18 ± 1.15 in control vector infected and 5.87 ± 1.23 with no infection; both P < 0.05) at 15 d after treatment. TUNEL analysis demonstrated that E2F-1 overexpression promoted tumor cell apoptosis(18.6% ± 2.3% vs 6.7% ± 1.2% in control vector infected 6.3% ± 1.2% for no infection; both P < 0.05). Furthermore, lentiviral vector-mediated E2F-1 overexpression increased theexpression of Bax and suppressed survivin, Bcl-2, cyclin D1, Skp2, and c-Myc expression in tumor tissue.CONCLUSION: E2F-1 inhibits growth of GC cells via regulating multiple signaling pathways, and may play an important role in targeted therapy for GC. 展开更多
关键词 E2F-1 GASTRIC cancer LENTIVIRAL vector Mouse model
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siRNA targeting of Cdx2 inhibits growth of human gastric cancer MGC-803 cells 被引量:14
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作者 xiao-Tong Wang Yu-Bo Xie qiang xiao 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第16期1903-1914,共12页
AIM:To investigate the effects of small interference RNA(siRNA) targeting of Cdx2 on human gastric cancer MGC-803 cells in vitro and in vivo.METHODS:The recombinant pSilencer 4.1-Cdx2 siRNA plasmids were constructed a... AIM:To investigate the effects of small interference RNA(siRNA) targeting of Cdx2 on human gastric cancer MGC-803 cells in vitro and in vivo.METHODS:The recombinant pSilencer 4.1-Cdx2 siRNA plasmids were constructed and transfected into gastric cancer MGC-803 cells in vitro.The stable transfectants were selected.The effects of Cdx2 siRNA on growth,proliferation,cell cycle,apoptosis,migration and invasiveness of human gastric cancer MGC-803 cells were evaluated and the expression of phosphatase and tensin homolog(PTEN),caspase-9 and caspase-3 was observed in vitro by reverse transcription polymerase chain reaction(RT-PCR) and Western blotting analysis.We also investigated the effect of Cdx2 siRNA on growth of MGC-803 cells in nude mice in vivo.RESULTS:Cdx2 siRNA led to inhibition of endogenous Cdx2 mRNA and protein expression as determined by RT-PCR and Western blotting analysis.Cdx2 siRNA significantly inhibited cell growth and proliferation,blocked entry into the S-phase of the cell cycle,induced cell apoptosis,and reduced the motility and invasion of MGC-803 cells.Cdx2 siRNA also increased PTEN expression,and activated caspase-9 and caspase-3 in MGC-803 cells in vitro.In addition,siRNA targeting of Cdx2 inhibited the growth of MGC-803 cells and promoted tumor cell apoptosis in vivo in nude mice tumor models.CONCLUSION:Cdx2 was involved in regulating progression of human gastric cancer cells MGC-803.Manipulation of Cdx2 expression may be a potential therapeutic strategy for gastric cancer. 展开更多
关键词 CDX2 Gastric cancer GROWTH Small interference RNA
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New insights into the functions and localization of the homeotic gene CDX2 in gastric cancer 被引量:10
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作者 Lin-Hai Yan Wei-Yuan Wei +1 位作者 Yu-Bo Xie qiang xiao 《World Journal of Gastroenterology》 SCIE CAS 2014年第14期3960-3966,共7页
Gastric cancer is one of the most frequent cancers, and it ranks the third most common cancer in China. The most recently caudal-related homeobox transcription factor 2 (CDX2) is expressed in a large number of human g... Gastric cancer is one of the most frequent cancers, and it ranks the third most common cancer in China. The most recently caudal-related homeobox transcription factor 2 (CDX2) is expressed in a large number of human gastrointestinal cancers. In addition, gastric epithelial cell mutations in CDX2 result in tumor promotion, which is characterized by cellular drug resistance and a high proclivity for developing cancer. A series of publications over the past years suggests a mechanism by which CDX2 overexpression results in multidrug resistance. CDX2 appears to forward control regenerating IV and the multidrug resistance 1 expression signaling pathway for regulation of cell drug resistance. 展开更多
关键词 Caudal-related homeobox transcription factor 2 Gastric cancer Intestinal metaplasia Apoptosis Drug resistance
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Joint Modulations of Electromagnetic Waves and Digital Signals on a Single Metasurface Platform to Reach Programmable Wireless Communications 被引量:2
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作者 Xiang Wan Chaokun xiao +10 位作者 He Huang qiang xiao Wei Xu Yueheng Li Joerg Eisenbeis Jiawei Wang Ziai Huang qiang Cheng Shi Jin Thomas Zwick Tiejun Cui 《Engineering》 SCIE EI 2022年第1期86-95,共10页
In current wireless communication and electronic systems,digital signals and electromagnetic(EM)radiation are processed by different modules.Here,we propose a mechanism to fuse the modulation of digital signals and th... In current wireless communication and electronic systems,digital signals and electromagnetic(EM)radiation are processed by different modules.Here,we propose a mechanism to fuse the modulation of digital signals and the manipulation of EM radiation on a single programmable metasurface(PM).The PM consists of massive subwavelength-scale digital coding elements.A set of digital states of all elements forms simultaneous digital information roles for modulation and the wave-control sequence code of the PM.By designing digital coding sequences in the spatial and temporal domains,the digital information and farfield patterns of the PM can be programmed simultaneously and instantly in desired ways.For the experimental demonstration of the mechanism,we present a programmable wireless communication system.The same system can realize transmissions of digital information in single-channel modes with beamsteerable capability and multichannel modes with multiple independent information.The measured results show the excellent performance of the programmable system.This work provides excellent prospects for applications in fifth-or sixth-generation wireless communications and modern intelligent platforms for unmanned aircrafts and vehicles. 展开更多
关键词 Joint radar and communication Programmable metasurface Massive multiple-in and multiple-out
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Convenient and Efficient Synthesis of L-Rhamnopyranosyl Phosphoramidates via H-Phosphonate 被引量:1
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作者 Qi SUN qiang xiao +1 位作者 Yong JU Yu Fen ZHAO 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第7期685-688,共4页
The a-L-rhamnopyranosyl phosphomonoesters conjugated with L-amino acid methyl esters were stereoselectively synthesized in a convenient route by utilizing H-phosphonate intermediate.
关键词 H-PHOSPHONATE L-rhamnose phosphoramidate.
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An Improved Method of Total Synthesis of 2-Methoxypodocarpane-8,11,13-triene
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作者 qiang xiao Yu Xin CUI Peng Fei TU 《Chinese Chemical Letters》 SCIE CAS CSCD 2001年第3期197-198,共2页
12-Methoxypodocarpane-8,11,13-triene 1, the key intermediate in the synthesis of some important diterpenes, was synthesized in an efficient way, which has the characteristics of short route simple operation and high y... 12-Methoxypodocarpane-8,11,13-triene 1, the key intermediate in the synthesis of some important diterpenes, was synthesized in an efficient way, which has the characteristics of short route simple operation and high yield. 展开更多
关键词 Synthesis DITERPENES 12-methoxypodocarpane-8 11 13-triene cyclization.
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A Concise Approach to the Synthesis of Carnosic Acid Type Diterpenes
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作者 Yu Xin CUI qiang xiao Peng Fei TU 《Chinese Chemical Letters》 SCIE CAS CSCD 2001年第3期203-204,共2页
10-vinyl-8,11,13-podocatriene 8, which is a modal of Carnosic acid type diterpenes, has been synthesized by an expeditious convergent synthetic approach.
关键词 Carnosic acid SYNTHESIS DITERPENES CYCLIZATION ANTI-HIV
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Metabolome profiling of stratified seeds provides insight into the regulation of dormancy in Davidia involucrata
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作者 Shiming Deng qiang xiao +4 位作者 Cigui Xu Jian Hong Zhijun Deng Dan Jiang Shijia Luo 《Plant Diversity》 SCIE CAS CSCD 2022年第4期417-427,共11页
Dove tree(Davidia involucrata),a tertiary vestige species,is well-adapted to cool conditions.Dormancy in D.involucrata seed lasts for an extremely long period of time,typically between 3 and 4 years,and this character... Dove tree(Davidia involucrata),a tertiary vestige species,is well-adapted to cool conditions.Dormancy in D.involucrata seed lasts for an extremely long period of time,typically between 3 and 4 years,and this characteristic makes the species an excellent model for studying the mechanisms of seed dormancy.The molecular mechanisms governing germination control in D.involucrata are still unknown.Seed stratification have been reported to enhance germination in recalcitrant seeds.We performed a widely targeted metabolome profiling to identify metabolites and associated pathways in D.involucrata seeds from six different moist sand stratification durations(0-30 months) using the ultra-high-performance liquid chromatography-Q Exactive Orbitrap-Mass spectrometry.There was an increasing germination rate with prolonged stratification durations(12-30 months).Furthermore,we detected 10,008 metabolites in the stratified seeds.We also detected 48 differentially accumulated metabolites(DAMs) between all stratification periods in the seeds,with 10 highly conserved metabolites.Most of the differentially accumulated metabolites between unstratified and stratified seeds were enriched in purine metabolism,pyrimidine metabolism,flavone and flavonol biosynthesis,phenylpropanoid biosynthesis,and arginine biosynthesis pathways.Key phytohormones,abscisic acid,indole-3 acetic acid,and sinapic acid were differentially accumulated in the seeds and are predicted to regulate dormancy in D.involucrata.We have provided extensive metabolic information useful for future works on dove tree germination study. 展开更多
关键词 Dove tree METABOLOME DORMANCY Abscisic acid STRATIFICATION
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Driving forest succession in karst areas of Chongqing municipality over the past decade
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作者 qiang xiao Yang xiao +1 位作者 Yuan Liu Jianping Tao 《Forest Ecosystems》 SCIE CSCD 2020年第1期26-36,共11页
Background:Karst areas in southwestern China exhibit ecological degradation in the form of rocky desertification.Local governments launched large-scale afforestation and other ecological restoration programs to curb t... Background:Karst areas in southwestern China exhibit ecological degradation in the form of rocky desertification.Local governments launched large-scale afforestation and other ecological restoration programs to curb this trend.Soil thickness is a key limiting factor for vegetation restoration in Karst areas,but the relationship between ecological restoration and soil thickness remains unclear.Further,afforestation consumes large amounts of water,which impacts water supply in karst areas.In this study,we used GIS and statistical analyses to determine rocky desertification sensitivity and its driving factors in karst areas of Chongqing municipality over the past decade.Results:Soil thickness is one of the key factors that restrict ecological restoration of rocky desertification.From 2000 to 2010,rocky desertification sensitivity in karst areas was on the rise along with an increase in afforestation.Areas of high sensitivity were mainly distributed in Pengshui County,Wulong District,and Youyang County;Shizhu County had the lowest overall incidence of desertification.Spatial distribution of rocky desertification was significantly affected by rainfall and soil thickness.Regression analysis showed that the main factors controlling changes in rocky desertification in natural forest over time were precipitation which explained 23.73%of total variance,and soil thickness which explained 23.42%of total variance.Soil thickness and soil water content had a higher correlation coefficient(at 0.516)in natural forests than in planted forests.Conclusion:This study showed that increases in soil thickness in a karst area had a significant positive impact on the fragile ecological environment.This indicates that ecosystem restoration in karst areas will benefit from addressing soil thickness. 展开更多
关键词 Rocky DESERTIFICATION GIS KARST areas ECOLOGICAL restoration ECOLOGICAL DRIVERS
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Numerical simulation of flow field characteristics and the improvement of pressure oscillation of rotating detonation engine
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作者 Xin-pei Han Quan Zheng +6 位作者 Bao-xing Li qiang xiao Han Xu Fang Wang Hao-long Meng Wen-kang Feng Chun-sheng Weng 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第8期191-202,共12页
Due to the inherent working mode of rotating detonation engine(RDE),the detonation flow field has the characteristics of pressure oscillation and axial kinetic energy loss,which makes it difficult to design nozzle and... Due to the inherent working mode of rotating detonation engine(RDE),the detonation flow field has the characteristics of pressure oscillation and axial kinetic energy loss,which makes it difficult to design nozzle and improve propulsion performance.Therefore,in order to improve the characteristics of detonation flow field,the three-dimensional numerical simulation of annular chamber and hollow chamber is carried out with premixed hydrogen/air as fuel in this paper,and then tries to combine the two chambers to weaken the oscillation characteristics of detonation flow field through the interaction of detonation flow field,which is a new method to regulate the detonation flow field.The results show that there are four states of velocity vectors at the outlet of annular chamber and hollow chamber,which makes RDE be affected by rolling moment and results in the loss of axial kinetic energy.In the external flow field of combined chamber,the phenomenon of cyclic reflection of expansion wave and compression wave on the free boundary is observed,which results in Mach disk structure.Moreover,the pressure monitoring points are set at the external flow field.The pressure signal shows that the high-frequency pressure oscillation at the external flow field of the combined chamber has been greatly weakened.Compared to the annular chamber,the relative standard deviation(RSD) has been reduced from 14.6% to5.6%.The results thus demonstrate that this method is feasible to adjust the pressure oscillation characteristics of the detonation flow field,and is of great significance to promote the potential of RDE and nozzle design. 展开更多
关键词 Detonation flow field Combined chamber Pressure oscillation Velocity vector
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Preparation and Properties of Chinese Lacquer Modified by Methylolureas
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作者 qiang xiao Yanjun Cao +6 位作者 Hailu Tan Qiaoling Feng Xinyue Gu Jianhua Lyu Hui xiao Ming Chen Yuzhu Chen 《Journal of Renewable Materials》 SCIE EI 2023年第2期1003-1016,共14页
In this study,different molar of methylolureas(MMU)were used to improve the properties and drying speed of the raw lacquer(RL).The drying time,gloss,pencil hardness and impact resistance of the lacquer film were teste... In this study,different molar of methylolureas(MMU)were used to improve the properties and drying speed of the raw lacquer(RL).The drying time,gloss,pencil hardness and impact resistance of the lacquer film were tested.The thermal behaviors and chemical structures of the lacquer membrane were also discussed by thermal gravimetric analysis(TGA),fourier infrared spectrometer(FT-IR)and nuclear magnetic resonance(NMR)analysis,respectively.The results demonstrated that lower molar ratio MMU can significantly improve the properties of lacquer.The TGA analysis showed that the modified lacquer had high thermal stability than that of the control.The FT-IR and 13C NMR analysis revealed that the structures of the modified lacquer were significantly improved by cross-linking with the hydroxymethyl groups and methylene methyl ethers of MMU.In addition,through scanning electron microscopy(SEM)characterization,it was found that the introduction of MMU can effectively improve the surface smoothness of the lacquer film. 展开更多
关键词 Raw lacquer methylolureas PROPERTIES thermal behavior chemical structure
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Recent advances in electrocatalytic generation of indole-derived radical cations and their applications in organic synthesis
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作者 Wei Zhou Xi Chen +3 位作者 Lin Lu Xian-Rong Song Mu-Jia Luo qiang xiao 《Chinese Chemical Letters》 SCIE CAS CSCD 2024年第4期106-123,共18页
Indole-derived radical cations, open-shell reactive species, display distinctive dual reactivity due to the carbon-centered radical and more electrophilic carbocation, which frequently appear in a variety of single el... Indole-derived radical cations, open-shell reactive species, display distinctive dual reactivity due to the carbon-centered radical and more electrophilic carbocation, which frequently appear in a variety of single electron oxidation reactions for synthesizing structurally diverse functionalized indoles and indolines. Electrocatalysis is considered as a synthetically attractive and environmentally friendly alternative for driving the single electron oxidation of indoles. Remarkable achievements in electrocatalytic indolederived radical cation-mediated indole functionalization have been realized so far. This review comprehensively summarizes the recent progresses in the applications of electrocatalytic indole radical cations,including C(sp~2)–H functionalization, dearomative 2,3-difunctionalization, and ring-opening reaction, emphasizing the vital single electron oxidation steps of indoles, the substrates scope and limitations, and the reaction mechanisms. 展开更多
关键词 ELECTROCATALYSIS Indole radical cation C-H functionalizatin Dearomative 2 3-difunctionalization
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Performance test of a half-feed peanut-cleaning picker suitable for clay hill areas in southern China
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作者 Shenying Wang Zhaoyan You +3 位作者 Dawei Sun qiang xiao Qiaojun Luo Lin He 《International Journal of Agricultural and Biological Engineering》 SCIE 2024年第4期156-164,共9页
To solve the problems of excessive soil lumps,broken branches and seedlings in pods and difficulty in removing impurities in the harvested pods of peanuts in the hilly areas of southern China,which is due to the high ... To solve the problems of excessive soil lumps,broken branches and seedlings in pods and difficulty in removing impurities in the harvested pods of peanuts in the hilly areas of southern China,which is due to the high soil viscosity and easy hardening,and to improve the soil removal effect of the peanut half-feed pod picker in hilly areas of China,this article designed a half-feed peanut-cleaning picker suitable for southern clay hilly areas and provided a detailed introduction to the overall structure,working principle,and adjustment methods of various operating parameters.Through field measurement experiments,the influencing factors and laws of soil removal performance indicators,such as the comprehensive soil removal rate and POD drop rate,were studied.The results showed that the comprehensive soil removal rate gradually increased with increasing soil patting frequency,soil patting amplitude,and picking roller speed,first increased and then decreased with increasing picking roller gap and gradually decreased with increasing soil patting plate gap and clamping conveyor chain speed.The comprehensive soil removal rate of the soil patting plate using the opposite patting method was greater than that of the swinging patting method.The soil removal pod drop rate increased gradually with increasing soil patting frequency and amplitude and decreased with increasing soil patting plate gap and clamping conveyor chain speed.The soil removal pod drop rate of the soil patting plate using swing patting was lower than that using the opposite patting method.The speed and gap of the picking roller had no effect on the soil removal pod drop rate.The frequency,amplitude,form,and gap of the soil patting plate had extremely significant impacts on the rate of decrease in the number of soil removal pod drop rate.The clamping conveyor chain speed had a significant impact,while the speed and gap of the picking roller had no significant impact.The influence of all factors on the comprehensive soil removal rate was extremely significant.This study provides a theoretical basis and technical reference for parameter optimization research on peanut-cleaning picking machines in the clay hilly areas of southern China. 展开更多
关键词 PEANUT southern clay hilly areas PICKER comprehensive soil removal rate soil removal pod drop rate
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Two-cut system suggested for tall wheatgrass to balance herbage yield and quality in the coastal saline–alkaline land around the Bohai Sea
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作者 Wei Li qiang xiao +4 位作者 Hongwei Li Hao Chang Qi Zheng Bin Li Zhensheng Li 《Grassland Research》 2024年第2期132-146,共15页
Background:Tall wheatgrass is a perennial salt-tolerant bunchgrass,which is a promising candidate for establishing a“Coastal Grass Belt”in China,particularly in the coastal saline–alkaline soils surrounding the Boh... Background:Tall wheatgrass is a perennial salt-tolerant bunchgrass,which is a promising candidate for establishing a“Coastal Grass Belt”in China,particularly in the coastal saline–alkaline soils surrounding the Bohai Sea.Methods:Seven harvesting treatments were performed to explore the optimal harvesting time and frequency for tall wheatgrass in coastal area.The dry matter yield(DMY)and forage nutritional values were investigated for each cut.The correlation between harvesting time and frequency thereof among the investigated traits was also determined.Results:The results showed that the two-cut on June 18 and October 29 produced the highest DMY.Another two-cut on May 26 and October 29 produced a relatively high crude protein(CP)yield.The DMY,contents of neutral detergent fiber(NDF),acid detergent fiber(ADF),and crude cellulose(CC)as well as CP yield were positively correlated to plant height,while the CP content and the relative feed value(RFV)were negatively correlated to plant height.The accumulating growing degree days,accumulated precipitation,and sunshine duration were positively correlated with plant height,DMY,contents of NDF,ADF,and CC as well as CP yield,but negatively correlated with CP content and RFV for the first cut.Conclusions:The two-cut treatment at the end of May and October may be suitable for tall wheatgrass in the“Coastal Grass Belt”targeted area. 展开更多
关键词 Coastal Grass Belt Elytrigia elongata saline and alkaline soils tall wheatgrass Thinopyrum ponticum
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