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The Stochastic Asymptotic Stability Analysis in Two Species Lotka-Volterra Model
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作者 yuqin li Yuehua He 《Applied Mathematics》 2023年第7期450-459,共10页
The asymptotic stability of two species stochastic Lotka-Volterra model is explored in this paper. Firstly, the Lotka-Volterra model with random parameter is built and reduced into the equivalent deterministic system ... The asymptotic stability of two species stochastic Lotka-Volterra model is explored in this paper. Firstly, the Lotka-Volterra model with random parameter is built and reduced into the equivalent deterministic system by orthogonal polynomial approximation. Then, the linear stability theory and Routh-Hurwitz criterion for nonlinear deterministic systems are applied to the equivalent one. At last, at the aid of Lyapunov second method, we obtain that as the random intensity or statistical parameter of random variable is changed, the stability about stochastic Lotka-Volterra model is different from the deterministic system. 展开更多
关键词 Asymptotic Stability Stochastic Lotka-Volterra Model Lyapunov Method
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Effects of ion-exchange on the pervaporation performance and microstructure of NaY zeolite membrane
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作者 Meihua Zhu Xingguo An +3 位作者 Tian Gui Ting Wu yuqin li Xiangshu Chen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第7期176-181,共6页
Pervaporation performance of NaY zeolite membranes is improved by ion-exchange with di-valent nitrate salt.Different nitrate salts,including Co(NO_(3))_(2),Mg(NO_(3))_(2),Zn(NO_(3))_(2),Ca(NO_(3))_(2),Cu(NO_(3))_(2),K... Pervaporation performance of NaY zeolite membranes is improved by ion-exchange with di-valent nitrate salt.Different nitrate salts,including Co(NO_(3))_(2),Mg(NO_(3))_(2),Zn(NO_(3))_(2),Ca(NO_(3))_(2),Cu(NO_(3))_(2),KNO_(3),and AgNO_(3),have great effects on the channel structure and water affinity of the NaY zeolite membrane.When the concentration of nitrate salt,ion-exchange temperature and time are 0.1 mol·L^(-1),50℃and 2 h,the ion-exchange degree order of NaY zeolites is Ag^(+)>K^(+)>Ca^(2+)>Zn^(2+)>>Co^(2+)>Mg^(2+).Especially,Ag^(+)and K^(+)cation exchange degree of NaY zeolites are achieved to 96.54% and 82.77% in this work.BET surface,total pore capacity,pore size distribution and water contact angle of the ion-exchanged NaY zeolites are all disordered by mono-and di-valent cations.Di-valent nitrate salt is favor for increasing the dehydration performance of NaY zeolite membranes by ion-exchange.When the ion-exchange solution is Zn(NO_(3))_(2),the total flux variation and separation factor variation of the NaY membrane(M-5)are -45% and 230% for separation of 10%(mass)H_(2)O/EtOH mixture by pervaporation,and the ion-exchanged membranes showed good reproducibility. 展开更多
关键词 NaY zeolite membrane Ion-exchange PERVAPORATION
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Growth process and short chain alcohol separation performance of fluoride-containing NaY zeolite membrane 被引量:1
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作者 Xiaopan Chen Meihua Zhu +7 位作者 Sitong Xiang Tian Gui TingWu yuqin li NaHu Izumi Kumakiri Xiangshu Chen Hidetoshi Kita 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第1期154-159,共6页
Growth process of the NaY zeolite membranes was investigated by fluoride-containing precursor synthesis gel.Compared with the fluoride-free precursor synthesis gel,the irregular NaY zeolite crystals were dissolved int... Growth process of the NaY zeolite membranes was investigated by fluoride-containing precursor synthesis gel.Compared with the fluoride-free precursor synthesis gel,the irregular NaY zeolite crystals were dissolved into amorphous by the fluoride-containing precursor synthesis gel initially,the amorphous contained the Y-type zeolite characteristic bands by the IR characterization.The fine square NaY zeolite crystals arose from the amorphous,which were accumulated and gradually grew into a dense NaY zeolite layer on the support surface after 6.5 h.Because the excessive NaY zeolites were dissolved by the strong alkaline and fluoride-containing precursor synthesis gel,there was plenty of amorphous on NaY zeolites layer for prolonging the crystallization time.The assynthesized NaY zeolite membranes had a good separation performance and repeatability for separation of 10 wt%methanol(MeOH)/methyl methacrylate(MMA) mixture by pervaporation,the flux and separation factor were(1.27 ± 0.07) kg·M^(-2)·h^(-1) and(4900 ± 1500) at 323 K,respectively.Besides,the NaY zeolite membranes were applied to separate the other short chain alcohol from the various alcohol/organic ester and alcohol/organic ether mixtures,the NaY zeolite membranes showed high short chain alcohol perm-selectivity. 展开更多
关键词 NaY zeolite membrane Growth process Fluoride-containing Short chain alcohols PERVAPORATION
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军校《机械原理》课程教学改革浅谈
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作者 杨竹芳 李玉琴 安志斌 《教育研究前沿(中英文版)》 2017年第4期229-232,共4页
本文针对机械原理课程教学现状所出现的问题做出分析,就信息化建设下机械原理课程教学模式与教学内容进行研究,并提出了改革方案和措施,为军队院校机械原理课程的教学质量提高做了探讨,提高了学员发现问题、分析问题和解决问题的能力.
关键词 机械原理 教学改革 教学内容
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非小细胞肺癌小活检标本质量与EGFR基因突变检出率关系分析 被引量:3
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作者 李玉勤 顾莹莹 姜桔红 《中国肺癌杂志》 CAS CSCD 北大核心 2021年第5期331-337,共7页
背景与目的表皮生长因子受体(epidermal growth factor receptor, EGFR)是非小细胞肺癌(non-small celllungcancer,NSCLC)患者中突变率最高的基因,准确检测出其突变类型有助于指导患者接受靶向药物治疗从而延长患者生存期。为了得到准... 背景与目的表皮生长因子受体(epidermal growth factor receptor, EGFR)是非小细胞肺癌(non-small celllungcancer,NSCLC)患者中突变率最高的基因,准确检测出其突变类型有助于指导患者接受靶向药物治疗从而延长患者生存期。为了得到准确的检查结果,基因检测平台对标本质量有一定要求。已有文献报道标本的肿瘤细胞数量及其比例等会影响EGFR基因突变检出率,本研究旨在分析NSCLC小活检标本质量与突变扩增系统(amplification refractory mutation system, ARMS)法检测EGFR基因突变检出率的关系。方法收集299例小活检肺腺癌病例的临床特征、在显微镜下评估切片的肿瘤细胞数量及比例、标本提取的DNA浓度、EGFR基因突变检测结果,分析标本质量与EGFR基因突变检出率的关系。结果肿瘤细胞数≤500组与>500组EGFR基因突变阳性率分别为40.7%(11/27)、43.8%(119/272),两者间无统计学差异(P=0.764)。DNA浓度≤20.4 ng/μL组及>20.4 ng/μL组的基因突变阳性率分别为42.7%(64/150)、44.3%(66/149),两者间无统计学差异(P=0.776)。肿瘤细胞比例≤30%及>30%组的阳性率分别为29.4%(20/68)、47.6%(110/231),两者间存在统计学差异(P=0.008)。多因素Logistic分析显示男性、甲状腺转录因子1(thyroid transcription factor-1, TTF-1)阴性、有吸烟史及肿瘤细胞比例<30%是影响EGFR基因突变低检出率的主要因素。结论在达到检测的最低要求后,肿瘤细胞比例仍可影响EGFR基因突变检出率。有必要在基因检测切片后再次评估最后一张切片的肿瘤细胞比例,对于肿瘤细胞比例过低的标本,建议通过显微切割等方法富集肿瘤细胞,提高其肿瘤细胞比例,得出更准确的检测结果。对于无法进行肿瘤细胞富集的标本,可行循环肿瘤DNA(circulating tumor DNA, ct DNA)检测作为补充,若结果仍为阴性才需考虑再次活检获取足够的肿瘤标本进行分子检测。 展开更多
关键词 肺肿瘤 表皮生长因子受体突变 肿瘤细胞数量 肿瘤细胞比例
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Feeding citrus flavonoid extracts decreases bacterial endotoxin and systemic inflammation and improves immunometabolic status by modulating hindgut microbiome and metabolome in lactating dairy cows
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作者 Yuchao Zhao Shiqiang Yu +4 位作者 liuxue li Huiying Zhao yuqin li linshu Jiang Ming liu 《Animal Nutrition》 SCIE CAS CSCD 2023年第2期386-400,共15页
The objectives of this study were to determine the effects of dietary supplementation with citrus flavonoid extracts(CFE)on milk performance,serum biochemistry parameters,fecal volatile fatty acids,fecal microbial com... The objectives of this study were to determine the effects of dietary supplementation with citrus flavonoid extracts(CFE)on milk performance,serum biochemistry parameters,fecal volatile fatty acids,fecal microbial community,and fecal metabolites in dairy cows.Eight multiparous lactating Holstein cows were used in a replicated 4×4 Latin square design(21-day period).Cows were fed a basal diet without addition(CON)or basal diet with added CFE at 50(CFE50),100(CFE10),and 150 g/d(CFE150).Feeding CFE up to 150 g/d increased milk yield and milk lactose percentage.Supplementary CFE linearly decreased milk somatic cell count.Serum cytokines interleukin-1β(IL-1β),IL-2,IL-6,and tumor necrosis factor-α(TNF-α)concentrations decreased linearly as the levels of CFE increased.Cows in CFE150 had lower serum lipopolysaccharide and lipopolysaccharide binding protein compared with CON.These results indicate feeding CFE decreased systemic inflammation and endotoxin levels in dairy cows.Furthermore,feeding CFE linearly increased the concentrations of total volatile fatty acids,acetate,and butyrate in feces.The relative abundances of beneficial bacteria Bifidobacterium spp.,Clostridium coccoides-Eubacterium rectale group,and Faecalibacterium prausnitzii in feces increased linearly with increasing CFE supplementation.The diversity and community structure of fecal microbiota were un-affected by CFE supplementation.However,supplementing CFE reduced the relative abundances of genera Ruminococcus_torques_group,Roseburia,and Lachnospira,but increased genera Bacteroides and Phascolarctobacterium.Metabolomics analysis showed that supplementary CFE resulted in a significant modification in the fecal metabolites profile.Compared with CON,fecal naringenin,hesperetin,hippuric acid,and sphingosine concentrations were greater in CFE150 cows,while fecal GlcCer(d18:1/20:0),Cer(d18:0/24:0),Cer(d18:0/22:0),sphinganine,and deoxycholic acid concentrations were less in CFE150 cows.Predicted pathway analysis suggested that"sphingolipid metabolism"was significantly enriched.Overall,these results indicate that citrus flavonoids could exert health-promoting effects by modulating hindgut microbiome and metabolism in lactating cows. 展开更多
关键词 Citrus flavonoid Dairy cow Fecal microbiota Systemic inflammation Volatile fatty acid
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Problems and Challenges Associated with Renaming Non-alcoholic Fatty Liver Disease to Metabolic Associated Fatty Liver Disease
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作者 Minghui Zeng lin Chen +2 位作者 yuqin li Yuqiang Mi liang Xu 《Infectious Diseases & Immunity》 CSCD 2023年第3期105-113,共9页
Non-alcoholic fatty liver disease(NAFLD)has become the world’s largest chronic liver disease in the 21st century,affecting 20%-30%of the world’s population.As the epidemiology,etiology,and pathogenesis of NAFLD have... Non-alcoholic fatty liver disease(NAFLD)has become the world’s largest chronic liver disease in the 21st century,affecting 20%-30%of the world’s population.As the epidemiology,etiology,and pathogenesis of NAFLD have been studied in-depth,it has been gradually recognized that most patients with NAFLD have one or more combined metabolic abnormalities known as metabolic syndrome.In 2020,the international expert group changed the name of NAFLD to metabolic-associated fatty liver disease(MAFLD)and proposed new diagnostic criteria for MAFLD and MAFLD-related liver cirrhosis,as well as the conceptual framework of other cause-related fatty liver diseases to avoid diagnosis based on the exclusion of other causes and better reflect its pathogenesis.However,there are still many ambiguities in the term,and changing the name does not address the unmet key needs in the field.The change from NAFLD to MAFLD was not just a change of definition.The problems and challenges are summarized as follows:epidemiology,children,rationality of"metabolism,"diagnostic criteria,double/multiple causes,drug discovery,clinical trials,and awareness raising.Metabolic-associated fatty liver disease has complex disease characteristics,and there are still some problems that need to be solved. 展开更多
关键词 Non-alcoholic fatty liver disease CHALLENGE HEPATIC Metabolic-associated fatty liver disease RENAME
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Transcriptomic and Macroscopic Architectures of Multimodal Covariance Network Reveal Molecular–Structural–Functional Co-alterations
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作者 lin Jiang Yueheng Peng +11 位作者 Runyang He Qingqing Yang Chanlin Yi yuqin li Bin Zhu Yajing Si Tao Zhang Bharat B.Biswal Dezhong Yao Lan Xiong Fali li Peng Xu 《Research》 SCIE EI CSCD 2024年第1期471-487,共17页
Human cognition is usually underpinned by intrinsic structure and functional neural co-activation in spatially distributed brain regions.Owing to lacking an effective approach to quantifying the covarying of structure... Human cognition is usually underpinned by intrinsic structure and functional neural co-activation in spatially distributed brain regions.Owing to lacking an effective approach to quantifying the covarying of structure and functional responses,how the structural–functional circuits interact and how genes encode the relationships,to deepen our knowledge of human cognition and disease,are still unclear.Here,we propose a multimodal covariance network(MCN)construction approach to capture interregional covarying of the structural skeleton and transient functional activities for a single individual.We further explored the potential association between brain-wide gene expression patterns and structural–functional covarying in individuals involved in a gambling task and individuals with major depression disorder(MDD),adopting multimodal data from a publicly available human brain transcriptomic atlas and 2 independent cohorts.MCN analysis showed a replicable cortical structural–functional fine map in healthy individuals,and the expression of cognition-and disease phenotype-related genes was found to be spatially correlated with the corresponding MCN differences.Further analysis of cell type-specific signature genes suggests that the excitatory and inhibitory neuron transcriptomic changes could account for most of the observed correlation with task-evoked MCN differences. 展开更多
关键词 alterations EVOKED spatially
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Corrosion mechanism investigation of TiN/Ti coating and TC4 alloy for aircraft compressor application 被引量:11
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作者 Zhiping SUN Guangyu HE +2 位作者 Qingjie MENG yuqin li Xiaodong TIAN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2020年第6期1824-1835,共12页
It is imperative to develop multifunctional erosion and corrosion resistant coatings for compressor blades of aircraft engines in harsh environment.PVD(Physical Vapor Deposition)technology has the advances in processi... It is imperative to develop multifunctional erosion and corrosion resistant coatings for compressor blades of aircraft engines in harsh environment.PVD(Physical Vapor Deposition)technology has the advances in processing erosion-resistant coatings;however,the performance of PVD coatings to combat corrosion depends on various coating defects.Determining and comparing the corrosion performances of PVD TiN/Ti coating and uncoated TC4 alloy was the main objective of present work.The 960 h salt spray corrosion and 116 h hot corrosion tests were conducted to simulate the grounding and working environments of the aircraft compressors.The corrosion mechanisms due to the coating defects such as pinhole,columnar boundary and large grain were analyzed based on the OM,Confocal microscope,electrochemical measurements,SEM,XRD and EDS results.Owing to the disordered state associated with the columnar boundary and the coating defect,nitrogen could be easily replaced by oxygen in the hot corrosion process,these structures were channels for fast diffusion of oxygen.Moreover,the Gibbs energy changes of Ti oxidation and TiN oxidation were thermodynamically calculated according to the working condition of aircraft compressors,and considerable research effort was focused on mapping out the phase diagram of Ti,TiN and high pressure gases.The findings of this research can provide insights into developing multifunctional coatings for future aircraft engines. 展开更多
关键词 Coaling defects Hot corrosion MICROSTRUCTURE Salt spray corrosion TiN/Ti coating
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Sedimentary and hydrological studies of the Holocene palaeofloods in the middle reaches of the Jinghe River 被引量:3
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作者 Xiaochun Zha Chunchang Huang +1 位作者 Jiangli Pang yuqin li 《Journal of Geographical Sciences》 SCIE CSCD 2012年第3期470-478,共9页
Palaeo 水文学领域调查在 Jinghe 河的中间的活动范围被执行。一套 palaeoflood slackwater 存款床在河岸在 Holocene 黄土土壤顺序被识别。沉积样品从侧面,和粒子尺寸分发被收集,磁性的危险性, loss-on-ignition 在实验室被分析。... Palaeo 水文学领域调查在 Jinghe 河的中间的活动范围被执行。一套 palaeoflood slackwater 存款床在河岸在 Holocene 黄土土壤顺序被识别。沉积样品从侧面,和粒子尺寸分发被收集,磁性的危险性, loss-on-ignition 在实验室被分析。分析结果证明 palaeoflood slackwater 存款在 Jinghe 河山谷记录了非凡的洪水事件。根据 stratigraphic 关联并且 OSL 标明日期, palaeoflood 事件被标明日期到 41004000 一 BP。palaeoflood 山峰分泌物被估计是由使用水文学模型的 19,41022,280 m3/s 并且由不同途径检查。这些结果把 Jinghe 河的洪水数据顺序扩大了到 10,000 年的时间规模。它在 Jinghe 河排水盆为水力的工程并且为洪水危险的缓解提供了重要数据。 展开更多
关键词 泾河流域 全新世黄土 古水文 沉积物 洪水事件 古土壤序列 实验室分析 光释光测年
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TRIM28 protects CARM1 from proteasome-mediated degradation to prevent colorectal cancer metastasis 被引量:1
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作者 Jinyuan Cui Jia Hu +5 位作者 Zhilan Ye Yongli Fan yuqin li Guobin Wang lin Wang Zheng Wang 《Science Bulletin》 SCIE EI CAS CSCD 2019年第14期986-997,共12页
TRIM28 (Tripartite motif-containing protein 28), a member of TRIM family, is aberrantly expressed and reportedly has different functions in many types of human cancer. However, the biological roles of TRIM28 and relat... TRIM28 (Tripartite motif-containing protein 28), a member of TRIM family, is aberrantly expressed and reportedly has different functions in many types of human cancer. However, the biological roles of TRIM28 and related mechanism in colorectal cancer (CRC) remain unclear. Here, we showed that TRIM28 was downregulated in colorectal cancer compared with normal mucosa, especially at advanced stages, and acted as an independent prognostic factor of favorable outcome. Functional studies demonstrated that TRIM28 restrained CRC migration and invasion in vitro and in vivo. Mechanistically, we reported that CARM1 (co-activator-associated arginine methyltransferase1) was a critical player downstream of TRIM28. TRIM28 interacted with CARM1, and protected CARM1 from proteasome-mediated degradation through physical protein-protein interaction to suppress CRC metastasis. Further, TRIM28 suppressed the migration and invasion of CRC cells through inhibiting WNT/β-catenin signaling in a CARM1-dependent manner, but independent of CARM1′s methyltransferase activity. The protein expression of CARM1 was positively correlated with TRIM28 in CRC tissues. Patients with high levels of TRIM28 and CARM1 had improved prognosis, whereas patients with low TRIM28 and CARM1 expression had the poor outcomes. Thus, our study reveals an inhibitory role of TRIM28 in CRC metastasis, which was achieved through a TRIM28-CARM1-WNT/β-catenin axis. This work provides potential prognostic and therapeutic targets for CRC treatment. 展开更多
关键词 COLORECTAL cancer Metastasis TRIM28 CARMI UBIQUITINATION WNT/Β-CATENIN
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Simultaneous extraction of level 2 and level 3 characteristics from latent fingerprints imaged with quantum dots for improved fingerprint analysis
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作者 yuqin li Chaoying Xu +2 位作者 Chang Shu Xiandeng Hou Peng Wu 《Chinese Chemical Letters》 SCIE CAS CSCD 2017年第10期1961-1964,共4页
Fingerprints are unique and life-long to everyone, so they occupy very important statuses in forensic science. However, due to the limit of current imaging technologies and instruments, recognition and matching of fin... Fingerprints are unique and life-long to everyone, so they occupy very important statuses in forensic science. However, due to the limit of current imaging technologies and instruments, recognition and matching of fingerprints are mostly based on their level 2 structures(bifurcation, crossover, and etc.).Moreover, in real-world cases, fingerprints collected in the field are often incomplete or damaged, which adds further difficulty in fingerprint analysis. Quantum dots(QDs) are superior fluorescent imaging agents for latent fingerprints, which can provide both level 2 and level 3(sweat pores) details. Here, we used red-emitting N-acetylcysteine-capped Cd Te QDs as imaging agent for staining of eccrine LFPs. The numbers of level 2 and level 3 features that can be mapped are significantly larger than those obtained by cyanoacrylate fuming, a standard technique being adopted at forensic scene. Therefore, the level 2 and level 3 characteristics from QD-staining were simultaneously extracted for improved fingerprint analysis.A preliminary fingerprint matching based modified Pore Matching algorithm was thus developed based on the integration of both level 2 and level 3 characteristics. Satisfactory results of fingerprint matching were obtained, demonstrating the advantage of the QD-staining for advanced fingerprint analysis. 展开更多
关键词 Quantum dots Latent fingerprints Sweat pore Fluorescent imaging Fingerprint matching
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