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R-Factor Analysis of Data Based on Population Models Comprising R- and Q-Factors Leads to Biased Loading Estimates
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作者 André Beauducel 《Open Journal of Statistics》 2024年第1期38-54,共17页
Effects of performing an R-factor analysis of observed variables based on population models comprising R- and Q-factors were investigated. Although R-factor analysis of data based on a population model comprising R- a... Effects of performing an R-factor analysis of observed variables based on population models comprising R- and Q-factors were investigated. Although R-factor analysis of data based on a population model comprising R- and Q-factors is possible, this may lead to model error. Accordingly, loading estimates resulting from R-factor analysis of sample data drawn from a population based on a combination of R- and Q-factors will be biased. It was shown in a simulation study that a large amount of Q-factor variance induces an increase in the variation of R-factor loading estimates beyond the chance level. Tests of the multivariate kurtosis of observed variables are proposed as an indicator of possible Q-factor variance in observed variables as a prerequisite for R-factor analysis. 展开更多
关键词 R-Factor Analysis q-Factor Analysis Loading Bias model Error Multivariate Kurtosis
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Effects of mesenchymal stem cell on dopaminergic neurons,motor and memory functions in animal models of Parkinson's disease:a systematic review and meta-analysis 被引量:4
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作者 Jong Mi Park Masoud Rahmati +2 位作者 Sang Chul Lee Jae Il Shin Yong Wook Kim 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第7期1584-1592,共9页
Parkinson’s disease is chara cterized by the loss of dopaminergic neurons in the substantia nigra pars com pacta,and although restoring striatal dopamine levels may improve symptoms,no treatment can cure or reve rse ... Parkinson’s disease is chara cterized by the loss of dopaminergic neurons in the substantia nigra pars com pacta,and although restoring striatal dopamine levels may improve symptoms,no treatment can cure or reve rse the disease itself.Stem cell therapy has a regenerative effect and is being actively studied as a candidate for the treatment of Parkinson’s disease.Mesenchymal stem cells are considered a promising option due to fewer ethical concerns,a lower risk of immune rejection,and a lower risk of teratogenicity.We performed a meta-analysis to evaluate the therapeutic effects of mesenchymal stem cells and their derivatives on motor function,memory,and preservation of dopamine rgic neurons in a Parkinson’s disease animal model.We searched bibliographic databases(PubMed/MEDLINE,Embase,CENTRAL,Scopus,and Web of Science)to identify articles and included only pee r-reviewed in vivo interve ntional animal studies published in any language through J une 28,2023.The study utilized the random-effect model to estimate the 95%confidence intervals(CI)of the standard mean differences(SMD)between the treatment and control groups.We use the systematic review center for laboratory animal expe rimentation’s risk of bias tool and the collaborative approach to meta-analysis and review of animal studies checklist for study quality assessment.A total of 33studies with data from 840 Parkinson’s disease model animals were included in the meta-analysis.Treatment with mesenchymal stem cells significantly improved motor function as assessed by the amphetamine-induced rotational test.Among the stem cell types,the bone marrow MSCs with neurotrophic factor group showed la rgest effect size(SMD[95%CI]=-6.21[-9.50 to-2.93],P=0.0001,I^(2)=0.0%).The stem cell treatment group had significantly more tyrosine hydroxylase positive dopamine rgic neurons in the striatum([95%CI]=1.04[0.59 to 1.49],P=0.0001,I^(2)=65.1%)and substantia nigra(SMD[95%CI]=1.38[0.89 to 1.87],P=0.0001,I^(2)=75.3%),indicating a protective effect on dopaminergic neurons.Subgroup analysis of the amphetamine-induced rotation test showed a significant reduction only in the intracranial-striatum route(SMD[95%CI]=-2.59[-3.25 to-1.94],P=0.0001,I^(2)=74.4%).The memory test showed significant improvement only in the intravenous route(SMD[95%CI]=4.80[1.84 to 7.76],P=0.027,I^(2)=79.6%).Mesenchymal stem cells have been shown to positively impact motor function and memory function and protect dopaminergic neurons in preclinical models of Parkinson’s disease.Further research is required to determine the optimal stem cell types,modifications,transplanted cell numbe rs,and delivery methods for these protocols. 展开更多
关键词 ANIMAL animal experimentation mesenchymal stem cells models Parkinson’s disease stem cell transplantation
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May ChatGPT be a tool producing medical information for common inflammatory bowel disease patients’questions?An evidencecontrolled analysis 被引量:2
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作者 Antonietta Gerarda Gravina Raffaele Pellegrino +6 位作者 Marina Cipullo Giovanna Palladino Giuseppe Imperio Andrea Ventura Salvatore Auletta Paola Ciamarra Alessandro Federico 《World Journal of Gastroenterology》 SCIE CAS 2024年第1期17-33,共17页
Artificial intelligence is increasingly entering everyday healthcare.Large language model(LLM)systems such as Chat Generative Pre-trained Transformer(ChatGPT)have become potentially accessible to everyone,including pa... Artificial intelligence is increasingly entering everyday healthcare.Large language model(LLM)systems such as Chat Generative Pre-trained Transformer(ChatGPT)have become potentially accessible to everyone,including patients with inflammatory bowel diseases(IBD).However,significant ethical issues and pitfalls exist in innovative LLM tools.The hype generated by such systems may lead to unweighted patient trust in these systems.Therefore,it is necessary to understand whether LLMs(trendy ones,such as ChatGPT)can produce plausible medical information(MI)for patients.This review examined ChatGPT’s potential to provide MI regarding questions commonly addressed by patients with IBD to their gastroenterologists.From the review of the outputs provided by ChatGPT,this tool showed some attractive potential while having significant limitations in updating and detailing information and providing inaccurate information in some cases.Further studies and refinement of the ChatGPT,possibly aligning the outputs with the leading medical evidence provided by reliable databases,are needed. 展开更多
关键词 Crohn’s disease Ulcerative colitis Inflammatory bowel disease Chat Generative Pre-trained Transformer Large language model Artificial intelligence
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基于全局响应面算法的Q235B钢的Johnson-Cook模型参数最优
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作者 苏绍娟 武玉杰 +4 位作者 王国回 苗哲 熊野萍 郭方昕 刘海波 《哈尔滨工程大学学报(英文版)》 CSCD 2024年第2期470-478,共9页
This study investigates the mechanical properties of Q235B steel through quasi-static tests at both room temperature and elevated temperature.The initial values of the Johnson-Cook model parameters are determined usin... This study investigates the mechanical properties of Q235B steel through quasi-static tests at both room temperature and elevated temperature.The initial values of the Johnson-Cook model parameters are determined using a fitting method.The global response surface algorithm is employed to optimize and calibrate the Johnson-Cook model parameters for Q235B steel under both room temperature and elevated temperature conditions.A simulation model is established at room temperature,and the simulated mechanical performance curves for displacement and stress are monitored.Multiple optimization algorithms are applied to optimize and calibrate the model parameters at room temperature.The global response surface algorithm is identified as the most suitable algorithm for this optimization problem.Sensitivity analysis is conducted to explore the impact of model parameters on the objective function.The analysis indicates that the optimized material model better fits the experimental values,aligning more closely with the actual test results of material strain mechanisms over a wide temperature range. 展开更多
关键词 q235B Mechanical property test Numerical simulation Johnson cook model Global response surface algorithm
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Elevation transition of aquatic insects closely matches a thermal feature in the Yungas of Northwestern Argentina
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作者 Alexandra BUITRAGO-GUACANAME Carlos MOLINERI +1 位作者 Andrés LIRA-NORIEGA Daniel Andrés DOS SANTOS 《Journal of Mountain Science》 SCIE CSCD 2024年第2期433-448,共16页
Temperature is a key factor that shapes the distribution of organisms.Having knowledge about how species respond to temperature is relevant to devise strategies for addressing the impacts of climate change.Aquatic ins... Temperature is a key factor that shapes the distribution of organisms.Having knowledge about how species respond to temperature is relevant to devise strategies for addressing the impacts of climate change.Aquatic insects are particularly vulnerable to climate change,yet there is still much to learn about their ecology and distribution.In the Yungas ecoregion of Northwestern Argentina,cold-and warm-adapted species of the orders Ephemeroptera,Plecoptera,and Trichoptera(EPT)are segregated by elevation.We modeled the ecological niche of South American EPT species in this region using available data and projected their potential distribution in geographic space.Species were grouped based on their ecogeographic similarity,and we analyzed their replacement pattern along elevation gradients,focusing on the ecotone where opposing thermal preferences converge.Along this interface,we identified critical points where the combined incidence of cold and warm assemblages maximizes,indicating a significant transition zone.We found that the Montane Cloud Forest holds the interface,with a particularly greater suitability at its lower boundary.The main axis of the interface runs in a N-S direction and falls between 14°C-16°C mean annual isotherms.The probability of a particular location within a basin being classified as part of the interface increases as Kira’s warmth index approaches a score around 150.Understanding the interface is critical for defining the thermal limits of species distribution and designing biomonitoring programs.Changes in the location of thermal constants related to mountainous ecotones may cause vertical displacement of aquatic insects and vegetation communities.We have recognized significant temperature thresholds that serve as indicators of suitability for the interface.As global warming is anticipated to shift these indicators,we suggest using them to monitor the imprints of climate change on mountain ecosystems. 展开更多
关键词 Austral Yungas Ecological Niche model EPHEMEROPTERA Kira’s warmth index PLECOPTERA TRICHOPTERA
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A Model of Grand Unified Theory: Suggested Solution for CP-Violation Using Ideas of Phase Paths
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作者 Hung-Te Henry Su Po-Han Lee 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第4期1878-1902,共25页
This study demonstrates that beyond standard model (BSM) cosmic fundamental interactions—weak, strong, and electromagnetic forces—can be unified through a common basis of representation. This unification allows for ... This study demonstrates that beyond standard model (BSM) cosmic fundamental interactions—weak, strong, and electromagnetic forces—can be unified through a common basis of representation. This unification allows for the derivation of the fine structure constant with running points of α(t) ≈ 1/(136.9038) at high energy scales, based on electroweak interactions. Through the application of the Ising model, the running point of the elementary charge e at high energy scales is determined, and Coulomb’s law is actually derived from the Yukawa potential. Theoretically, based on S. Weinberg’s electroweak interaction theory, this study unifies the strong and electromagnetic forces by representing them with rYuka, and further advances the reconstruction of the SU(3)C×SU(1)L×U(1)EMframework on the basis of electroweak interaction concepts. In fact, the cosmic fundamental forces can interchange at the mass gap, defined as the Yukawa turning phase at rYuka ≃1.9404 fm, with the SU(3)Diag structural constant fijk on glueballs calculated, estimating a spectrum mass gap of ∆0 > 0. 展开更多
关键词 BsM ELECTROWEAK GLUEBALLs Ising model Mass Gap s. Weinberg
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Real-Time Co-optimization of Gear Shifting and Engine Torque for Predictive Cruise Control of Heavy-Duty Trucks
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作者 Hongqing Chu Xiaoxiang Na +4 位作者 Huan Liu Yuhai Wang Zhuo Yang Lin Zhang Hong Chen 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第2期294-317,共24页
Fuel consumption is one of the main concerns for heavy-duty trucks.Predictive cruise control(PCC)provides an intriguing opportunity to reduce fuel consumption by using the upcoming road information.In this study,a rea... Fuel consumption is one of the main concerns for heavy-duty trucks.Predictive cruise control(PCC)provides an intriguing opportunity to reduce fuel consumption by using the upcoming road information.In this study,a real-time implementable PCC,which simultaneously optimizes engine torque and gear shifting,is proposed for heavy-duty trucks.To minimize fuel consumption,the problem of the PCC is formulated as a nonlinear model predictive control(MPC),in which the upcoming road elevation information is used.Finding the solution of the nonlinear MPC is time consuming;thus,a real-time implementable solver is developed based on Pontryagin’s maximum principle and indirect shooting method.Dynamic programming(DP)algorithm,as a global optimization algorithm,is used as a performance benchmark for the proposed solver.Simulation,hardware-in-the-loop and real-truck experiments are conducted to verify the performance of the proposed controller.The results demonstrate that the MPC-based solution performs nearly as well as the DP-based solution,with less than 1%deviation for testing roads.Moreover,the proposed co-optimization controller is implementable in a real-truck,and the proposed MPC-based PCC algorithm achieves a fuel-saving rate of 7.9%without compromising the truck’s travel time. 展开更多
关键词 Heavy-duty truck Predictive cruise control model predictive control Pontryagin’s maximum principle Real-truck implementation
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Evaluating the role of large language models in inflammatory bowel disease patient information
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作者 Eun Jeong Gong Chang Seok Bang 《World Journal of Gastroenterology》 SCIE CAS 2024年第29期3538-3540,共3页
This letter evaluates the article by Gravina et al on ChatGPT’s potential in providing medical information for inflammatory bowel disease patients.While promising,it highlights the need for advanced techniques like r... This letter evaluates the article by Gravina et al on ChatGPT’s potential in providing medical information for inflammatory bowel disease patients.While promising,it highlights the need for advanced techniques like reasoning+action and retrieval-augmented generation to improve accuracy and reliability.Emphasizing that simple question and answer testing is insufficient,it calls for more nuanced evaluation methods to truly gauge large language models’capabilities in clinical applications. 展开更多
关键词 Crohn’s disease Ulcerative colitis Inflammatory bowel disease Chat generative pre-trained transformer Large language model Artificial intelligence
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The Collaboratory for the Study of Earthquake Predictability in China:Experiment Design and Preliminary Results of CSEP2.0
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作者 ZHANG Shengfeng ZHANG Yongxian +3 位作者 Maximilian J.WERNER Kenny G.RAHAM David A.RHOADES JoséA.BAYONA 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第S01期94-97,共4页
Since the inaugural international collaboration under the framework of the Collaboratory for the Study of Earthquake Predictability(CSEP)in 2007,numerous forecast models have been developed and operated for earthquake... Since the inaugural international collaboration under the framework of the Collaboratory for the Study of Earthquake Predictability(CSEP)in 2007,numerous forecast models have been developed and operated for earthquake forecasting experiments across CSEP testing centers(Schorlemmer et al.,2018).Over more than a decade,efforts to compare forecasts with observed earthquakes using numerous statistical test methods and insights into earthquake predictability,which have become a highlight of the CSEP platform. 展开更多
关键词 earthquake forecasting seismicity modeling CsEP2.0 Pattern Informatics(PI)algorithm long-to-intermediate-term forecast Relative Intensity(RI)algorithm Completeness Magnitude s test N test
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基于UPLC-Q-TOF-MS/MS及网络药理学探讨多裂骆驼蓬治疗阿尔茨海默病的有效成分和作用机制
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作者 程亚敏 黄丹蓉 +3 位作者 任静玉 冯紫涵 周文斌 申刚义 《天然产物研究与开发》 CAS CSCD 北大核心 2024年第10期1787-1799,共13页
本研究通过超高效液相色谱-四极杆飞行时间串联质谱法(UPLC-Q-TOF-MS/MS)、网络药理学及分子对接技术探讨多裂骆驼蓬抗阿尔茨海默病(Alzheimer′s disease,AD)药效物质基础及作用机制。利用UPLC-Q-TOF-MS/MS技术对多裂骆驼蓬进行定性研... 本研究通过超高效液相色谱-四极杆飞行时间串联质谱法(UPLC-Q-TOF-MS/MS)、网络药理学及分子对接技术探讨多裂骆驼蓬抗阿尔茨海默病(Alzheimer′s disease,AD)药效物质基础及作用机制。利用UPLC-Q-TOF-MS/MS技术对多裂骆驼蓬进行定性研究;结合质谱分析结果,利用SWISS ADME、GeneCards等数据库筛选多裂骆驼蓬活性成分、对应靶点及疾病靶点;利用Venn绘制平台获取交集靶点,并导入STRING在线分析平台和Cytoscope3.9.1软件,进行蛋白质相互作用分析,构建药物-成分-靶点网络;利用AlzDate数据库差异表达模块分析靶点的表达与β-淀粉样蛋白(β-amyloids,Aβ)和微管相关蛋白(Tau)相关病理学的关系;通过DAVID数据库进行GO和KEGG通路富集分析;利用Autodock Vina软件实现核心靶点与有效成分分子对接模型的构建。从多裂骆驼蓬中共鉴定出34个主要成分,包括生物碱类10种,黄酮类5种,氨基酸类5种,萜类5种,核苷类2种,酚酸类3种,其他类化合物4种。网络药理学分析结果显示,吴茱萸碱、β-谷甾醇、β-豆甾醇酮和去氢骆驼蓬碱等活性成分可通过作用靶点调节一系列与AD发病机制相关的生物学过程、分子功能和信号通路,进而调节胆碱能系统和功能、减少Aβ损伤、调节微循环及神经元结构和功能发挥治疗AD的作用。分子对接显示有效成分吴茱萸碱、β-谷甾醇、β-豆甾醇酮和去氢骆驼蓬碱与核心靶点MAPK3和STAT3均具有良好的结合活性。该研究初步揭示了多裂骆驼蓬治疗AD的药效物质基础及作用机制,为临床应用和药物开发提供了依据。 展开更多
关键词 多裂骆驼蓬 阿尔茨海默病 UPLC-q-TOF-Ms/Ms技术 网络药理学
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Solving the Olbers’s Paradox, Explaining the “Red-Shift”, and Challenging the Relativities by “Sun Matters Theory” and “Sun Model of Universe”, an Evolution of the Einstein’s Static Universe Model
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作者 Wanpeng Sun 《Natural Science》 2024年第2期7-18,共12页
Olbers’s paradox, known as the dark night paradox, is an argument in astrophysics that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. Big-Bang theory was used ... Olbers’s paradox, known as the dark night paradox, is an argument in astrophysics that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. Big-Bang theory was used to partially explain this paradox, while introducing new problems. Hereby, we propose a better theory, named Sun Matters Theory, to explain this paradox. Moreover, this unique theory supports and extended the Einstein’s static universe model proposed by Albert Einstein in 1917. Further, we proposed our new universe model, “Sun Model of Universe”. Based on the new model and novel theory, we generated innovative field equation by upgrading Einstein’s Field Equation through adding back the cosmological constant, introducing a new variable and modifying the gravitationally-related concepts. According to the Sun Model of Universe, the dark matter and dark energy comprise the so-called “Sun Matters”. The observed phenomenon like the red shift is explained as due to the interaction of ordinary light with Sun Matters leading to its energy and frequency decrease. In Sun Model, our big universe consists of many universes with ordinary matter at the core mixed and surrounded with the Sun Matters. In those universes, the laws of physics may be completely or partially different from that of our ordinary universe with parallel civilizations. The darkness of night can be easily explained as resulting from the interaction of light with the Sun Matters leading to the sharp decrease in the light intensity. Sun Matters also scatter the light from a star, which makes it shining as observed by Hubble. Further, there is a kind of Sun Matters named “Sun Waters”, surrounding every starts. When lights pass by the sun, the Sun Waters deflect the lights to bend the light path. According to the Sun Model, it is the light bent not the space bent that was proposed in the theory of relativities. 展开更多
关键词 Olberss Paradox sun Matters Theory sun model of Universe Einstein’s Universe Dark Mass
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Geology and mineralization of the Hongqiling large magmatic nickel-copper-cobalt deposit(22×10^(4)t)in Jilin Province,China:A review
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作者 Cong Chen Yu-chao Gu +14 位作者 Di Zhang Tao-tao Wu Ai Li Yun-sheng Ren Qing-qing Shang Jian Zhang Xiong-fei Bian Fei Su Jia-lin Yang Qiu-shi Sun Xiao-hai Li Wan-zhen Liu Zhen-ming Sun Sen Zhang Yu-hui Feng 《China Geology》 CAS CSCD 2024年第4期762-796,共35页
The Hongqiling large nickel-copper-cobalt deposit(hereafter referred to as the Hongqiling deposit),a typical mafic-ultramafic copper-nickel deposit in China,boasts proven Ni(Ni)resources of approximately 22×10^(4... The Hongqiling large nickel-copper-cobalt deposit(hereafter referred to as the Hongqiling deposit),a typical mafic-ultramafic copper-nickel deposit in China,boasts proven Ni(Ni)resources of approximately 22×10^(4)t,associated copper resources of 2×10^(4)t,and associated cobalt(Co)resources of 0.5×10^(4)t,with Ni reserves ranking 10th among China's magmatic nickel deposits.Geotectonically,the Hongqiling deposit is situated in the superimposed zone between the Xing'an-Mongolian orogenic belt and the circum-Western Pacific's active continental margin belt.Its ore-bearing plutons occur within the metamorphic rocks of the Ordovician Hulan Group,with the emplacement of plutons and the locations of orebodies governed by the deep-seated Huifahe fault and its secondary NW-trending Fujia-Hejiagou-Beixinglong-Changsheng fault zone.In the deposit,the rock assemblages of ore-bearing plutons predominantly encompass gabbro-pyroxenite-olivine pyroxenite-pyroxene peridotite(pluton No.1)and norite-orthopyroxenite-harzburgite(pluton No.7),with ore-bearing lithofacies consisting primarily of olivine pyroxenite and pyroxenite facies.The Hongqiling deposit hosts stratoid,overhanging lentoid,veined,and pure-sulfide veined orebodies.Its ores principally contain metallic minerals including pyrrhotite,pentlandite,chalcopyrite,violarite,and pyrite.Despite unidentified magma sources of ore-bearing mafic-ultramafic rocks,it is roughly accepted that the magmatic evolution in the Hongqiling deposit primarily involved fractional crystallization and crustal contamination.The ore-forming materials were primarily derived from the upper mantle,mixed with minor crustal materials.The ore-bearing mafic-ultramafic rocks in the deposit,primarily emplaced during the Indosinian(208-239 Ma),were formed in an intense extension setting followed by the collisional orogeny between the North China Plate and the Songnen-Zhangguangcai Range Block during the Middle-Late Triassic.From the perspective of the metallogenic geological setting,surrounding rocks,ore-controlling structures,and rock assemblages,this study identified one favorable condition and seven significant indicators for prospecting for Hongqiling-type nickel deposits and developed a prospecting model of the Hongqiling deposit.These serve as valuable references for exploring similar nickel deposits in the region,as well as the deep parts and margins of the Hongqiling deposit. 展开更多
关键词 Nickel-copper-cobalt deposit Fractional crystallization Crustal contamination MAGMATIC MINERALIZATION Re-Os isotopic age sulfur isotopic Metallogenic mode Prospecting model Western Pacific’s active continental margin Mineral exploration engineering Hongqiling Jilin
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由Sălăvgean-q微分算子定义的具有对称共轭点的单叶调和函数类
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作者 马丽娜 李书海 《理论数学》 2024年第7期103-112,共10页
在单复变函数几何理论的研究中,构造函数类及研究它的几何性质是目前国内外重要的研究课题。本文首先定义了一个Sălăgean-q微分算子,利用该算子,我们构建了一类具有特殊性质的倒结构单叶调和函数,这类函数具有对称共轭点。我们进一步推... 在单复变函数几何理论的研究中,构造函数类及研究它的几何性质是目前国内外重要的研究课题。本文首先定义了一个Sălăgean-q微分算子,利用该算子,我们构建了一类具有特殊性质的倒结构单叶调和函数,这类函数具有对称共轭点。我们进一步推导出了这类函数的系数条件,并得到了相应的Fekete-Szegö不等式,这一发现有效地拓展了现有的知识范畴。这一成果不仅丰富了单复变函数的理论内容,也为调和函数的研究提供了新的视角和方法。更重要的是,这一研究可能为未来在信号处理、图像处理等领域的实际应用提供新的数学模型和算法基础。 展开更多
关键词 对称共轭点 sălăgean q微分算子 调和函数 Fekete-szegö不等式
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Hubble Tension Explanation from This Cosmological Model AΛΩ (Slow Bang Model, SB)
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作者 Jean Perron 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第1期106-125,共20页
In this article we present a model of Hubble-Lemaître law using the notions of a transmitter (galaxy) and a receiver (MW) coupled to a model of the universe (Slow Bang Model, SB), based on a quantum approach of t... In this article we present a model of Hubble-Lemaître law using the notions of a transmitter (galaxy) and a receiver (MW) coupled to a model of the universe (Slow Bang Model, SB), based on a quantum approach of the evolution of space-time as well as an equation of state that retains all the infinitesimal terms. We find an explanation of the Hubble tension H<sub>0</sub>. Indeed, we have seen that this constant depends on the transceiver pair which can vary from the lowest observable value, from photons of the CMB (theoretical [km/s/Mpc]) to increasingly higher values depending on the earlier origin of the formation of the observed galaxy or cluster (ETG ~0.3 [Gy], ~74 [km/s/Mpc]). We have produced a theoretical table of the values of the constant according to the possible pairs of transmitter/receiver in the case where these galaxies follow the Hubble flow without large disturbance. The calculated theoretical values of the constant are in the order of magnitude of all values mentioned in past studies. Subsequently, we applied the models to 9 galaxies and COMA cluster and found that the models predict acceptable values of their distances and Hubble constant since these galaxies mainly follow the Hubble flow rather than the effects of a galaxy cluster or a group of clusters. In conclusion, we affirm that this Hubble tension does not really exist and it is rather the understanding of the meaning of this constant that is questioned. 展开更多
关键词 model of the Universe Cosmological Constant Hubble Constant Hubble’s Tension Hubble-Lemaître Law Hubble’s Flow
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基于UHPLC-Q-TOF/MS技术分析肿节风总黄酮提取物促进巨核细胞分化的效应成分
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作者 张钟康 卢晓南 +4 位作者 卢震 胡佳 刘慧珍 卢婷 尚广彬 《中药新药与临床药理》 CAS CSCD 北大核心 2024年第1期56-64,共9页
目的筛选肿节风总黄酮提取物促进巨核细胞分化的效应成分。方法(1)以人巨核细胞白血病细胞(Dami)与人骨髓基质细胞(HS-5)共培养的方式建立巨核细胞分化障碍模型作为评价体系,实验分组:Dami组(Dami)、对照组(Dami+HS-5)、PMA组[Dami+HS-5... 目的筛选肿节风总黄酮提取物促进巨核细胞分化的效应成分。方法(1)以人巨核细胞白血病细胞(Dami)与人骨髓基质细胞(HS-5)共培养的方式建立巨核细胞分化障碍模型作为评价体系,实验分组:Dami组(Dami)、对照组(Dami+HS-5)、PMA组[Dami+HS-5+5 ng·mL-1佛波醇12-十四酸酯13-乙酸酯(PMA)]、模型组[Dami+HS-5+1%兔抗大鼠血小板血清(APS)+5 ng·mL-1PMA],培养48 h。采用流式细胞术检测巨核细胞分化成熟表面标记分子CD41a、CD61的表达情况。(2)将49只SD雄性大鼠随机分为空白血浆组、15 min组、30 min组、60 min组、90 min组、120 min组、240 min组,每组7只。各给药组大鼠灌胃肿节风总黄酮提取物1.26 g·kg^(-1),在6个设定时间点(15、30、60、90、120、240 min)采血制备肿节风总黄酮提取物经时含药血浆。(3)采用超高效液相色谱-四极杆串联飞行时间质谱法(UHPLC-Q-TOF/MS)对肿节风总黄酮提取物经时含药血浆进行分析,以峰面积构建肿节风总黄酮提取物经时含药血浆中的化学成分随时间变化量矩阵(X矩阵)。将所采集的6个不同时间点的肿节风总黄酮经时含药血浆对巨核细胞分化成熟障碍模型进行干预,采用流式细胞术检测细胞表面分子CD41a、CD61的表达水平,构建肿节风总黄酮提取物经时含药血浆效应矩阵(Y矩阵)。(4)将X矩阵和Y矩阵数据标准化处理后,采用偏最小二乘法(Partial least squares,PLS)计算分析量效关系,以变量重要性投影(Variable importance for projection,VIP)>1为阈值,筛选与细胞表面分子CD41a、CD61变化相关的效应成分,并进行化学成分鉴定,作为肿节风总黄酮提取物中促进巨核细胞分化的潜在效应成分,最后回归评价体系验证其药效。结果(1)与Dami组比较,对照组Dami细胞表面的CD41a表达水平明显升高(P<0.05)。与对照组比较,PMA组Dami细胞表面的CD41a、CD61表达水平均显著升高(P<0.01)。与PMA组比较,模型组Dami细胞表面的CD41a、CD61表达水平均显著降低(P<0.01)。(2)与空白血浆组比较,15、30、60、90、120、240 min各时间点Dami细胞表面分子CD41a、CD61表达水平均显著升高(P<0.01),且CD41a、CD61均在30 min组表达水平最高。在正、负离子模式下筛选出VIP值>1的潜在效应成分,并选取540.3638@12.25与559.2991@11.53两个成分进行药效学验证。559.2991@11.53被鉴定为胡萝卜苷(Daucosterol,Dau),540.3638@12.25被鉴定为迷迭香酸-4-O-β-D-葡萄糖(Rosmarinic acid 4-O-β-Dglucoside,Ros)。Ros、Dau分别干预巨核细胞分化成熟障碍模型后,与模型组比较,Ros及Dau低、中、高剂量组(40、60、80μg·mL-1)的Dami细胞表面的CD41a、CD61表达水平均显著升高(P<0.05,P<0.01)。结论Ros、Dau可能是肿节风总黄酮提取物促进巨核细胞分化的效应成分。 展开更多
关键词 肿节风总黄酮提取物 免疫性血小板减少症 巨核细胞分化障碍模型 人巨核白血病细胞 人骨髓基质细胞 超高效液相色谱-四极杆串联飞行时间质谱法 偏最小二乘法 胡萝卜苷 迷迭香酸-4-O-β-D-葡萄糖
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小直径钢管桩Q-s曲线的数值模拟与分析
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作者 郭琦 仲伟秋 +2 位作者 申永康 卜延渭 曹聪 《科技通报》 2024年第9期18-22,28,共6页
目前小直径钢管桩在工程领域内得到了广泛应用,但是为确定小直径钢管桩竖向承载力,通常需要采用静力荷载试验获取其荷载-沉降曲线作为其判断依据,然而原位试验不仅过程复杂,而且耗时较长,同时需要投入大量的人力和物力。利用理论模型推... 目前小直径钢管桩在工程领域内得到了广泛应用,但是为确定小直径钢管桩竖向承载力,通常需要采用静力荷载试验获取其荷载-沉降曲线作为其判断依据,然而原位试验不仅过程复杂,而且耗时较长,同时需要投入大量的人力和物力。利用理论模型推导获得小直径钢管桩的Q-s曲线,不仅可以省去现场试验的必要性,而且能提高设计和施工的效率。本文结合前人的研究,在桩土接触面单元的建立过程中参考了无厚度Goodman界面单元法,理论推导小直径钢管桩的Q-s曲线,并与实测结果对比分析,证明了该理论方法的适用性,并分析了结果存在误差的原因,鉴于较小的沉降对小直径钢管桩承载力的影响较小,因此工程实践中可以通过理论方法获取Q-s曲线。 展开更多
关键词 小直径钢管桩 q-s曲线 静载荷试验 刚度矩阵 沉降
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Analysis of Porter’s Five Forces Competitive Model in China’s Property Rights Trading Market
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作者 Weinong Wang 《Proceedings of Business and Economic Studies》 2024年第3期206-211,共6页
In recent years,China’s property rights trading market has been extremely competitive,but there are also new contradictions and challenges.This paper aims to analyze the external and internal competitive market of th... In recent years,China’s property rights trading market has been extremely competitive,but there are also new contradictions and challenges.This paper aims to analyze the external and internal competitive market of the property rights market through Porter’s five forces competition model,then find out the problems and defects in the development,thereby promoting the better development and progress of China’s property rights trading market. 展开更多
关键词 Porter’s five forces competitive model Market optimization Innovative development
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Q345R+S32168复合板压力容器的焊接工艺研究及应用
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作者 危永福 晏君文 刘丁华 《中国重型装备》 2024年第3期52-56,共5页
根据承制设备的结构,从材料分析、焊接材料及焊接方法选择、焊接工艺评定、焊接过程控制措施等方面,通过理论分析与现场生产的结合,对Q345R+S32168不锈钢复合板压力容器上的焊接工艺进行研究,并将研究成果在承制设备上成功进行应用。
关键词 q345R%PLUs%s32168复合板 压力容器 焊接
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基于Q-s曲线的大型LNG储罐桩板基础沉降计算方法
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作者 司漪 《化工与医药工程》 CAS 2024年第3期20-27,共8页
试桩Q-s曲线体现了现场桩基荷载和沉降的关系。文章以某LNG储罐桩板基础为背景,提出利用Q-s曲线求出桩端土层变形模量的方法,并考虑桩板共同作用的求解桩板基础沉降的方法。该方法将桩基模拟为非线性弹簧,弹簧刚度取自Q-s曲线,采用MIDA... 试桩Q-s曲线体现了现场桩基荷载和沉降的关系。文章以某LNG储罐桩板基础为背景,提出利用Q-s曲线求出桩端土层变形模量的方法,并考虑桩板共同作用的求解桩板基础沉降的方法。该方法将桩基模拟为非线性弹簧,弹簧刚度取自Q-s曲线,采用MIDAS进行建模求解,可得到设计需要的筏板和桩基的沉降等高线图以及轴力和弯矩图,用于指导设计。与仅考虑线性地弹簧系数的规范方法进行对比,该方法精度更高,与实际情况更加相符。该方法可针对不同位置的桩基输入不同的非线性弹簧,可用于解决复杂不均匀地层桩筏基础沉降计算的问题。 展开更多
关键词 q-s曲线 大型LNG储罐 桩板基础沉降 复杂地层 非线性弹簧
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Quantification of Ride Comfort Using Musculoskeletal Mathematical Model Considering Vehicle Behavior
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作者 Junya Tanehashi Szuchi Chang +4 位作者 Takahiro Hirosei Masaki Izawa Aman Goyal Ayumi Takahashi Kazuhito Misaji 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第6期2287-2306,共20页
This research aims to quantify driver ride comfort due to changes in damper characteristics between comfort mode and sport mode,considering the vehicle’s inertial behavior.The comfort of riding in an automobile has b... This research aims to quantify driver ride comfort due to changes in damper characteristics between comfort mode and sport mode,considering the vehicle’s inertial behavior.The comfort of riding in an automobile has been evaluated in recent years on the basis of a subjective sensory evaluation given by the driver.However,reflecting driving sensations in design work to improve ride comfort is abstract in nature and difficult to express theoretically.Therefore,we evaluated the human body’s effects while driving scientifically by quantifying the driver’s behavior while operating the steering wheel and the behavior of the automobile while in motion using physical quantities.To this end,we collected driver and vehicle data using amotion capture system and vehicle CAN and IMU sensors.We also constructed a three-dimensional musculoskeletal mathematical model to simulate driver movements and calculate the power and amount of energy per unit of time used for driving the joints and muscles of the human body.Here,we used comfort mode and sport mode to compare damper characteristics in terms of hardness.In comfort mode,damper characteristics are soft and steering stability is mild,but vibration from the road is not easily transmitted to the driver making for a lighter load on the driver.In sport mode,on the other hand,damper characteristics are hard and steering stability is comparatively better.Still,vibration from the road is easily transmitted to the driver,whichmakes it easy for a load to be placed on the driver.As a result of this comparison,it was found that a load was most likely to be applied to the driver’s neck.This result in relation to the neck joint can therefore be treated as an objective measure for quantifying ride comfort. 展开更多
关键词 Human engineering BIOMECHANICs driver’s sense of fatigue double lane change musculoskeletal mathematical model
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