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基于Alpha Shapes轮廓点云识别算法的洞室表面形变区域提取方法 被引量:1
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作者 张雨婷 郑德华 李思远 《南京信息工程大学学报》 北大核心 2025年第2期181-190,共10页
针对三维激光扫描密集点云提取洞室表面变形信息的问题,本文提出一种基于改进的Alpha Shapes算法识别洞室轮廓点云和多尺度模型到模型的点云比对(Multiscale Model-to-Model Cloud Comparison,M3C2)的洞室表面变形监测方法.首先对获取... 针对三维激光扫描密集点云提取洞室表面变形信息的问题,本文提出一种基于改进的Alpha Shapes算法识别洞室轮廓点云和多尺度模型到模型的点云比对(Multiscale Model-to-Model Cloud Comparison,M3C2)的洞室表面变形监测方法.首先对获取到的两期洞室表面点云数据进行配准,采用改进的Alpha Shapes算法识别洞室表面外轮廓点云.获得的两期洞室表面外轮廓点云经精配准后,再采用M3C2算法进行各点变形值计算,最后进行距离聚类提取连续形变区域.实验结果表明:该方法能够有效剔除点云中细小沟壑处的点及受到混合像元影响的点,在洞室截面到扫描仪距离10 m的范围内,两期点云剔除率分别为14.17%及13.52%,在70 m范围内,分别为6.25%及6.42%;该方法能够准确高效地提取出2倍配准误差以上的洞室表面形变区域. 展开更多
关键词 洞室变形监测 轮廓点云识别 Alpha shapes算法 M3C2算法
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Combing the Entropy Weight Method with Fuzzy Mathematics for Assessing the Quality and Post-Ripening Mechanism of High-Temperature Daqu during Storage 被引量:1
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作者 YANG Junlin YANG Shaojuan +8 位作者 WU Cheng YIN Yanshun YOU Xiaolong ZHAO Wenyu ZHU Anran WANG Jia HU Feng HU Jianfeng WANG Diqiang 《食品科学》 北大核心 2025年第9期48-62,共15页
This study investigated the physicochemical properties,enzyme activities,volatile flavor components,microbial communities,and sensory evaluation of high-temperature Daqu(HTD)during the maturation process,and a standar... This study investigated the physicochemical properties,enzyme activities,volatile flavor components,microbial communities,and sensory evaluation of high-temperature Daqu(HTD)during the maturation process,and a standard system was established for comprehensive quality evaluation of HTD.There were obvious changes in the physicochemical properties,enzyme activities,and volatile flavor components at different storage periods,which affected the sensory evaluation of HTD to a certain extent.The results of high-throughput sequencing revealed significant microbial diversity,and showed that the bacterial community changed significantly more than did the fungal community.During the storage process,the dominant bacterial genera were Kroppenstedtia and Thermoascus.The correlation between dominant microorganisms and quality indicators highlighted their role in HTD quality.Lactococcus,Candida,Pichia,Paecilomyces,and protease activity played a crucial role in the formation of isovaleraldehyde.Acidic protease activity had the greatest impact on the microbial community.Moisture promoted isobutyric acid generation.Furthermore,the comprehensive quality evaluation standard system was established by the entropy weight method combined with multi-factor fuzzy mathematics.Consequently,this study provides innovative insights for comprehensive quality evaluation of HTD during storage and establishes a groundwork for scientific and rational storage of HTD and quality control of sauce-flavor Baijiu. 展开更多
关键词 microbial community high-temperature Daqu comprehensive quality evaluation entropy weight method maturation process
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Study on the formation characteristics of underwater hemispherical shaped charge jet and its penetration performance into concrete 被引量:1
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作者 Chao Cao Jinxiang Wang +5 位作者 Lingquan Kong Kui Tang Yujie Xiao Yangchen Gu Ming Yang Jian Wang 《Defence Technology(防务技术)》 2025年第5期180-196,共17页
Shaped charge has been widely used for penetrating concrete.However,due to the obvious difference between the propagation of shock waves and explosion products in water and air,the theory governing the formation of sh... Shaped charge has been widely used for penetrating concrete.However,due to the obvious difference between the propagation of shock waves and explosion products in water and air,the theory governing the formation of shaped charge jets in water as well as the underwater penetration effect of concrete need to be studied.In this paper,we introduced a modified forming theory of an underwater hemispherical shaped charge,and investigated the behavior of jet formation and concrete penetration in both air and water experimentally and numerically.The results show that the modified jet forming theory predicts the jet velocity of the hemispherical liner with an error of less than 10%.The underwater jets exhibit at least 3%faster and 11%longer than those in air.Concrete shows different failure modes after penetration in air and water.The depth of penetration deepens at least 18.75%after underwater penetration,accompanied by deeper crater with 65%smaller radius.Moreover,cracks throughout the entire target are formed,whereas cracks exist only near the penetration hole in air.This comprehensive study provides guidance for optimizing the structure of shaped charge and improves the understanding of the permeability effect of concrete in water. 展开更多
关键词 shaped charge jet Underwater penetration Formation characteristic Concrete failure
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Benchmarking the composite performance of distinct shapes of ferrometallic gold nanoshells:photothermal cancer therapy 被引量:1
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作者 Sara I.Abdelsalam Essam T.Abdelwahab +2 位作者 I.M.Eldesoky Ramzy M.Abumandour M.M.Ahmed 《Acta Mechanica Sinica》 2025年第6期3-15,共13页
This article presents a detailed theoretical hybrid analysis of the magnetism and the thermal radiative heat transfer in the presence of heat generation affecting the behavior of the dispersed gold nanoparticles(AuNPs... This article presents a detailed theoretical hybrid analysis of the magnetism and the thermal radiative heat transfer in the presence of heat generation affecting the behavior of the dispersed gold nanoparticles(AuNPs)through the blood vessels of the human body.The rheology of gold-blood nanofluid is treated as magnetohydrodynamic(MHD)flow with ferromagnetic properties.The AuNPs take different shapes as bricks,cylinders,and platelets which are considered in changing the nanofluid flow behavior.Physiologically,the blood is circulated under the kinetics of the peristaltic action.The mixed properties of the slip flow,the gravity,the space porosity,the transverse ferromagnetic field,the thermal radiation,the nanoparticles shape factors,the peristaltic amplitude ratio,and the concentration of the AuNPs are interacted and analyzed for the gold-blood circulation in the inclined tube.The appropriate model for the thermal conductivity of the nanofluid is chosen to be the effective Hamilton-Crosser model.The undertaken nanofluid can be treated as incompressible non-Newtonian ferromagnetic fluid.The solutions of the partial differential governing equations of the MHD nanofluid flow are executed by the strategy of perturbation approach under the assumption of long wavelength and low Reynolds number.Graphs for the streamwise velocity distributions,temperature distributions,pressure gradients,pressure drops,and streamlines are presented under the influences of the pertinent properties.The practical implementation of this research finds application in treating cancer through a technique known as photothermal therapy(PTT).The results indicate the control role of the magnetism,the heat generation,the shape factors of the AuNPs,and its concentration on the enhancement of the thermal properties and the streamwise velocity of the nanofluid.The results reveal a marked enhancement in the temperature profiles of the nanofluid,prominently influenced by both the intensified heat source and the heightened volume fractions of the nanoparticles.Furthermore,the platelet shape is regarded as most advantageous for heat conduction owing to its highest effective thermal conductivity.AuNPs proved strong efficiency in delivering and targeting the drug to reach the affected area with tumors.These results offer valuable insights into evaluating the effectiveness of PTT in addressing diverse cancer conditions and regulating their progression. 展开更多
关键词 Peristaltic flow NANOFLUID AuNPs MAGNETISM shape factor Gravity Heat transfer Porous medium
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Experimental and numerical investigation of cavity characteristics in behind-armor liquid-filled containers under shaped charge jet impact 被引量:1
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作者 Shixin Ma Xiangdong Li Lanwei Zhou 《Defence Technology(防务技术)》 2025年第5期242-259,共18页
The cavity characteristics in liquid-filled containers caused by high-velocity impacts represent an important area of research in hydrodynamic ram phenomena.The dynamic expansion of the cavity induces liquid pressure ... The cavity characteristics in liquid-filled containers caused by high-velocity impacts represent an important area of research in hydrodynamic ram phenomena.The dynamic expansion of the cavity induces liquid pressure variations,potentially causing catastrophic damage to the container.Current studies mainly focus on non-deforming projectiles,such as fragments,with limited exploration of shaped charge jets.In this paper,a uniquely experimental system was designed to record cavity profiles in behind-armor liquid-filled containers subjected to shaped charge jet impacts.The impact process was then numerically reproduced using the explicit simulation program ANSYS LS-DYNA with the Structured Arbitrary Lagrangian-Eulerian(S-ALE)solver.The formation mechanism,along with the dimensional and shape evolution of the cavity was investigated.Additionally,the influence of the impact kinetic energy of the jet on the cavity characteristics was analyzed.The findings reveal that the cavity profile exhibits a conical shape,primarily driven by direct jet impact and inertial effects.The expansion rates of both cavity length and maximum radius increase with jet impact kinetic energy.When the impact kinetic energy is reduced to 28.2 kJ or below,the length-to-diameter ratio of the cavity ultimately stabilizes at approximately 7. 展开更多
关键词 Cavity characteristics shaped charge jet Behind-armor liquid-filled container Impact kinetic energy Hydrodynamic ram
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Stability Prediction in Smart Grid Using PSO Optimized XGBoost Algorithm with Dynamic Inertia Weight Updation
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作者 Adel Binbusayyis Mohemmed Sha 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第1期909-931,共23页
Prediction of stability in SG(Smart Grid)is essential in maintaining consistency and reliability of power supply in grid infrastructure.Analyzing the fluctuations in power generation and consumption patterns of smart ... Prediction of stability in SG(Smart Grid)is essential in maintaining consistency and reliability of power supply in grid infrastructure.Analyzing the fluctuations in power generation and consumption patterns of smart cities assists in effectively managing continuous power supply in the grid.It also possesses a better impact on averting overloading and permitting effective energy storage.Even though many traditional techniques have predicted the consumption rate for preserving stability,enhancement is required in prediction measures with minimized loss.To overcome the complications in existing studies,this paper intends to predict stability from the smart grid stability prediction dataset using machine learning algorithms.To accomplish this,pre-processing is performed initially to handle missing values since it develops biased models when missing values are mishandled and performs feature scaling to normalize independent data features.Then,the pre-processed data are taken for training and testing.Following that,the regression process is performed using Modified PSO(Particle Swarm Optimization)optimized XGBoost Technique with dynamic inertia weight update,which analyses variables like gamma(G),reaction time(tau1–tau4),and power balance(p1–p4)for providing effective future stability in SG.Since PSO attains optimal solution by adjusting position through dynamic inertial weights,it is integrated with XGBoost due to its scalability and faster computational speed characteristics.The hyperparameters of XGBoost are fine-tuned in the training process for achieving promising outcomes on prediction.Regression results are measured through evaluation metrics such as MSE(Mean Square Error)of 0.011312781,MAE(Mean Absolute Error)of 0.008596322,and RMSE(Root Mean Square Error)of 0.010636156 and MAPE(Mean Absolute Percentage Error)value of 0.0052 which determine the efficacy of the system. 展开更多
关键词 Smart Grid machine learning particle swarm optimization XGBoost dynamic inertia weight update
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孔掏槽爆破Shape-effect损伤理论分析及优化
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作者 秦辉峰 赵岩 +1 位作者 王海龙 何健辉 《工程爆破》 北大核心 2025年第2期21-31,46,共12页
为探究在不同形状的空孔下的掏槽爆破机理,基于空孔效应、应力集中效应及空间碎胀原理,建立了改进后的Shape-effect分段爆破二维损伤理论计算模型,结合模拟和试验分析爆破作用下掏槽区的围岩损伤情况,并以此给出“方空孔掏槽理论分析模... 为探究在不同形状的空孔下的掏槽爆破机理,基于空孔效应、应力集中效应及空间碎胀原理,建立了改进后的Shape-effect分段爆破二维损伤理论计算模型,结合模拟和试验分析爆破作用下掏槽区的围岩损伤情况,并以此给出“方空孔掏槽理论分析模型”优化方案。结果表明:改进后的圆空孔壁随时间变化的荷载函数γq 2 sinθ符合孔壁的实际应力,理论计算与数值模拟结果和试验的变化趋势基本一致。通过优化掏槽区的爆破效果,将圆空孔换为方孔空后,方孔空周围的岩体损伤分布均匀,破裂充分。掏槽区岩体空孔形状的改变影响周围岩体的应力分布,圆孔壁附近岩体产生“间隔环状”破坏,反射波的拉伸作用受到阻抗。方孔空掏槽爆破产生的纵波使孔壁大范围内岩体产生拉剪破坏,其在第二段应力波的影响下向内坍缩,空孔空间的利用率达63.527%。 展开更多
关键词 掏槽损伤 理论分析 数值模拟 shape-effect模型 动态演化
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Association Between Low Birth Weight and Dementia Risk:A Large-scale Prospective Study
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作者 YU Xinyue XUE Qingping +10 位作者 LI Jingyi ZHANG Peiqi OUYANG Qingqing LUO Xiaoxue HE Qian WANG Yongliu ZHAO Ying HE Xiangwang LI Fan YANG Yunhaonan PAN Xiongfei 《四川大学学报(医学版)》 北大核心 2025年第3期697-710,共14页
Objective To investigate the association between birth weight and dementia risk and the mediating roles of chronic diseases,and to assess potential biological pathways underlying the birth weight-associated dementia r... Objective To investigate the association between birth weight and dementia risk and the mediating roles of chronic diseases,and to assess potential biological pathways underlying the birth weight-associated dementia risk based on large-scale proteomics.Methods We used data from 279743 participants aged 40 to 69 years enrolled in the UK Biobank.Birth weight was categorized into low birth weight(≤2500 g),normal birth weight(2500-3999 g),and macrosomia(≥4000 g).Multivariable Cox proportional hazards regression models were used to assess the associations between birth weight categories and all-cause dementia and its subtypes(Alzheimer's disease and vascular dementia).Proteomics analyses were conducted to identify proteins and the potential pathways involved.Results Low birth weight was associated with higher risks for all-cause dementia and its subtypes.The hazard ratios were 1.18(95%CI,1.08-1.30)for all-cause dementia,1.14(95%CI,1.00-1.31)for Alzheimer's disease,and 1.22(95%CI,1.01-1.48)for vascular dementia.A non-linear relationship was observed between birth weight and dementia risk(P for nonlinearity<0.001).Certain cardiometabolic diseases in middle-aged adults,such as diabetes,stroke,hypertension,and dyslipidemia,played a significant mediating role in the relationship between low birth weight and dementia risk,with the mediation proportion being 6.3%to 15.8%.Proteomic analyses identified 21 proteins linked to both low birth weight and all-cause dementia risk,which were significantly enriched in the pathways for viral protein interaction with cytokines and cytokine receptors,adipocytokine signaling,and cytokine-cytokine receptor interaction.Conclusion Low birth weight is positively associated with dementia risk.Cardiometabolic diseases in middle-aged adults may mediate the relationship between low birth weight and dementia risk.A number of proteins and the associated pathways underscore the relationship between low birth weight and dementia risk. 展开更多
关键词 Birth weight DEMENTIA PROTEOMICS Alzheimer's disease Vascular dementia
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Effect of Co Content on Microstructure and Mechanical Properties of High-Entropy High-Temperature Shape Memory Alloy
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作者 Zhao Yanchun Jin Bo +4 位作者 Feng Yuanfei Ma Huwen Yu Zhiqi Feng Li Liaw Peter K 《稀有金属材料与工程》 北大核心 2025年第1期10-16,共7页
(TiZrHf)_(50)Ni_(30)Cu_(20-x)Co_(x)(x=2,4,6,at%)high-entropy high-temperature shape memory alloys were fabricated by watercooled copper crucible in a magnetic levitation vacuum melting furnace,and the effects of Co co... (TiZrHf)_(50)Ni_(30)Cu_(20-x)Co_(x)(x=2,4,6,at%)high-entropy high-temperature shape memory alloys were fabricated by watercooled copper crucible in a magnetic levitation vacuum melting furnace,and the effects of Co content on microstructure and mechanical properties were investigated.The results indicate that the grain size of the alloy decreases with increasing the Co content.In the as-cast state,the alloy consists primarily of the B19′phase,with a trace of B2 phase.The fracture morphology is predominantly composed of the B19′phase,whereas the B2 phase is nearly absent.Increasing the Co content or reducing the sample dimensions(d)markedly enhance the compressive strength and ductility of the alloy.When d=2 mm,the(TiZrHf)_(50)Ni_(30)Cu_(14)Co_(6) alloy demonstrates the optimal mechanical properties,achieving a compressive strength of 2142.39±1.8 MPa and a plasticity of 17.31±0.3%.The compressive cyclic test shows that with increasing the compressive strain,the residual strain of the(TiZrHf)_(50)Ni_(30)Cu_(14)Co_(6) alloy increases while the recovery ability declines.The superelastic recovery capability of the alloy is continuously enhanced.The superelastic recovery rate increases from 1.36%to 2.12%,the residual strain rate rises from 1.79%to 5.52%,the elastic recovery rate ascends from 3.86%to 7.36%,while the total recovery rate declines from 74.48%to 63.20%. 展开更多
关键词 high-temperature shape memory alloy high-entropy alloy MICROSTRUCTURE mechanical property
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A Note for Weighted Local Hardy Spaces
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作者 ZHAO Haijing LI Baode 《数学进展》 北大核心 2025年第5期1095-1101,共7页
Inhomogeneous Calderon-Zygmund operator T maps each atom into an approximate molecule of weighted local Hardy space if and only if some approximate cancellation condition holds for T.An equivalent norm for weighted Le... Inhomogeneous Calderon-Zygmund operator T maps each atom into an approximate molecule of weighted local Hardy space if and only if some approximate cancellation condition holds for T.An equivalent norm for weighted Lebesgue space which has vanishing moments up to order s plays an important role,where s∈N. 展开更多
关键词 local Hardy space Calderon-Zygmund operator Muckenhoupt weight
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The Paley-Wiener Theorem for General Weighted Hardy Spaces on Tube Domains
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作者 HUANG Yun ZHANG Dawei 《应用数学》 北大核心 2025年第3期841-849,共9页
In this paper,the Paley-Wiener theorem is extended to the analytic function spaces with general weights.We first generalize the theorem to weighted Hardy spaces Hp(0<p<∞)on tube domains by constructing a sequen... In this paper,the Paley-Wiener theorem is extended to the analytic function spaces with general weights.We first generalize the theorem to weighted Hardy spaces Hp(0<p<∞)on tube domains by constructing a sequence of L^(1)functions converging to the given function and verifying their representation in the form of Fourier transform to establish the desired result of the given function.Applying this main result,we further generalize the Paley-Wiener theorem for band-limited functions to the analytic function spaces L^(p)(0<p<∞)with general weights. 展开更多
关键词 Paley-Wiener Theorem Fourier transform weighted Hardy space Tube domain
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The molecular weight of carbon dots calculated from colligative properties and their application in estimating surface adsorption capacity
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作者 Ting Sun Xinzhi Liang +3 位作者 Minghao Pang Xia Xin Ning Feng Hongguang Li 《日用化学工业(中英文)》 北大核心 2025年第4期422-429,共8页
Since the discovery of carbon dots(CDs)in 2004,the unique photoluminescence phenomenon of CDs has attracted widespread attention.However,the molecular weight of CDs has not been adequately quantified at present,due to... Since the discovery of carbon dots(CDs)in 2004,the unique photoluminescence phenomenon of CDs has attracted widespread attention.However,the molecular weight of CDs has not been adequately quantified at present,due to CDs are atomically imprecise and their molecular weight distribution is broad.In this paper,a series of Pluronic-modified CDs were prepared and the structure of the CDs was briefly analyzed.Subsequently,a molecular weight measurement method based on colligative properties was developed,and the correction coefficient in the algorithm was briefly analyzed.The calculated molecular weight was applied to the determination of surface adsorption capacity.This work provided a method for averaging the molecular weight of atomically imprecise particulate materials,which is expected to provide new opportunities in related fields. 展开更多
关键词 carbon dots molecular weight colligative properties surface adsorption capacity
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Products of multiplication,composition and differentiation on weighted Bergman spaces in the unit ball
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作者 ZHANG Chao QIN Yuehai 《中山大学学报(自然科学版)(中英文)》 北大核心 2025年第2期160-169,共10页
The boundness and compactness of products of multiplication,composition and differentiation on weighted Bergman spaces in the unit ball are studied.We define the differentiation operator on the space of holomorphic fu... The boundness and compactness of products of multiplication,composition and differentiation on weighted Bergman spaces in the unit ball are studied.We define the differentiation operator on the space of holomorphic functions in the unit ball by radial derivative.Then we extend the Sharma's results. 展开更多
关键词 composition operator multiplication operator differentiation operator weighted Bergman space
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Association between Maternal Anthropometry and Neonatal Birth Weight among Women Who Came for Delivery in a Tertiary Health Facility, South East Nigeria
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作者 Chibueze Ogbodo Nweke Chijioke Stanley Anyigor-Ogah +7 位作者 Nnaemeka Christopher Oguejiofor Idika Mba Idika John Okafor Egede Ikenna Alphonsus Ozioko Chika Christiana Agunanne Augustina Chinweoke Anyigor-Ogah Chukwuemeka Benjamin Agunanne Chinyere Chibuzor Duru 《Advances in Reproductive Sciences》 2025年第1期24-36,共13页
Background: Birth weight has been identified as one of the most significant predictors of a child’s physical growth, development, and survival in later life. A quest to provide an answer on the impact of maternal ant... Background: Birth weight has been identified as one of the most significant predictors of a child’s physical growth, development, and survival in later life. A quest to provide an answer on the impact of maternal anthropometry on neonatal birth weight necessitated this study. Materials and methods: It is a cross-sectional descriptive hospital based study that involved 130 participants selected using a systematic sampling method, utilizing a semi-structured, pre-tested interviewer administered questionnaire. Data were collected using a standard procedure and were summarized using proportions, and the Chi square test was used to explore the association between categorical variables. Predictors of birth weight were determined using logistic regression. The level of statistical significance was set at p Results: Participants had a mean age of 28.6 ± 5.1 years, mean weight of 72.2 ± 11.2 kg and mean height of 1.63 ± 0.07m while the mean fetal birth weight was 3.10 ± 0.56 kg. There was a significant association between maternal delivery body mass index and neonatal birth weight (p Conclusion: The prevalence of low birth weight and macrosomia in this study population was high. The focus should be geared towards balanced nutrition support for all mothers at booking so as to mitigate the risks associated with these extremes of birth weight. 展开更多
关键词 MATERNAL ANTHROPOMETRY NEONATAL Birth weight Delivery
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2-complex Symmetric Weighted Composition Operators on Fock Space of C^(N)
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作者 JIANG Zhijie 《数学进展》 北大核心 2025年第1期37-49,共13页
The aim of the present paper is to study 2-complex symmetric bounded weighted composition operators on the Fock space of C^(N) with the conjugations J and J_(t,A,b) defined by ■ respectively,where k(z_(1),...,z_N)=(... The aim of the present paper is to study 2-complex symmetric bounded weighted composition operators on the Fock space of C^(N) with the conjugations J and J_(t,A,b) defined by ■ respectively,where k(z_(1),...,z_N)=(■,...,■),t∈C,b∈C^(N) and A is a linear operator on C^(N).An example of 2-complex symmetric bounded weighted composition operator with the conjugation J_(t,A,b) is given. 展开更多
关键词 Fock space weighted composition operator 2-complex symmetric operator reproducing kernel function
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Research on Construction of combined model weighting function and its application on aeromagnetic 3D inversion modeling
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作者 Gao Xiu-he Xiong Sheng-qing +2 位作者 Sun Si-yuan Zeng Zhao-fa Yu Chang-chun 《Applied Geophysics》 2025年第2期342-353,556,共13页
In the 3D inversion modeling of gravity and magnetic potential field data,the model weighting function is often applied to overcome the skin eff ect of inversion results.However,divergence occurs at the the deep area,... In the 3D inversion modeling of gravity and magnetic potential field data,the model weighting function is often applied to overcome the skin eff ect of inversion results.However,divergence occurs at the the deep area,and artificial weak negative anomalies form around the positive anomalies in the horizontal direction,resulting in a reduction in the overall resolution.To fully utilize the model weighting function,this study constructs a combined model weighting function.First,a new depth weighting function is constructed by adding a regulator into the conventional depth weighting function to overcome the skin eff ect and inhibit the divergence at the deep area of the inversion results.A horizontal weighting function is then constructed by extracting information from the observation data;this function can suppress the formation of artificial weak anomalies and improve the horizontal resolution of the inversion results.Finally,these two functions are coupled to obtain the combined model weighting function,which can replace the conventional depth weighting function in 3D inversion.It improves the vertical and horizontal resolution of the inversion results without increasing the algorithm complexity and calculation amount,is easy to operate,and adapts to any 3D inversion method.Two model experiments are designed to verify the effectiveness,practicability,and anti-noise of the combined model weighting function.Then the function is applied to the 3D inversion of the measured aeromagnetic data in the Jinchuan area in China.The obtained inversion results are in good agreement with the known geological data. 展开更多
关键词 horizontal weighting depth weighting combined weighting aeromagnetic data 3D inversion Jinchuan Orefield
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Shape Memory Properties of Short-Glass Fiber Reinforced Epoxy Composite Programmed below Glass Transition Temperature
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作者 Kartikey Shahi Velmurugan Ramachandran +1 位作者 Ranjith Mohan Boomurugan Ramachandran 《Journal of Polymer Materials》 2025年第2期477-496,共20页
A Shape Memory Polymer Composite(SMPC)is developed by reinforcing an epoxy-based polymer with randomly oriented short glass fibers.Diverging from previous research,which primarily focused on the hot programming of sho... A Shape Memory Polymer Composite(SMPC)is developed by reinforcing an epoxy-based polymer with randomly oriented short glass fibers.Diverging from previous research,which primarily focused on the hot programming of short glass fiber-based SMPCs,this work explores the potential for programming below the glass transition temperature(Tg)for epoxy-based SMPCs.To mitigate the inherent brittleness of the SMPC during deformation,a linear polymer is incorporated,and a temperature between room temperature and Tg is chosen as the deformation temperature to study the shape memory properties.The findings demonstrate an enhancement in shape fixity and recovery stress,alongside a reduction in shape recovery,with the incorporation of short glass fibers.In addition to tensile properties,thermal properties such as thermal conductivity,specific heat capacity,and glass transition temperature are investigated for their dependence on fiber content.Microscopic properties,such as fiber-matrix adhesion and the dispersion of glass fibers,are examined through Scanning Electron Microscope imaging.The fiber length distribution and mean fiber lengths are also measured for different fiber fractions. 展开更多
关键词 shape memory polymer composite glass fiber composite shape fixity shape recovery thermomechanical cycle
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Body Weight Management
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作者 PAN ZIYI ADIBASE RAPHAEL 《ChinAfrica》 2025年第7期60-61,共2页
The Double Take column looks at a single topic from an African and Chinese perspective.This month,we explore how young people respond to the increasing focus on body weight management.As obesity rates climb,body weigh... The Double Take column looks at a single topic from an African and Chinese perspective.This month,we explore how young people respond to the increasing focus on body weight management.As obesity rates climb,body weight management has become a growing concern in China.The government is introducing targeted policies,hospitals are setting up dedicated clinics,and health experts are speaking out.But weight is no longer just a medical issue-it’s increas-ingly tied to identity,confidence,and social image.We examine the cultural forces shaping how young people in China and Africa approach weight-what drives their choices,how ideals are formed,and where health meets appearance in today’s shifting societies. 展开更多
关键词 cultural forces HEALTH body weight managementas weight management young people China obesity rates body weight management
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Equivalent Conditions of Complete Convergence for Weighted Sums of Sequences of i.i.d.Random Variables under Sublinear Expectations
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作者 XU Mingzhou CHENG Kun 《应用概率统计》 北大核心 2025年第3期339-352,共14页
The complete convergence for weighted sums of sequences of independent,identically distributed random variables under sublinear expectation space is studied.By moment inequality and truncation methods,we establish the... The complete convergence for weighted sums of sequences of independent,identically distributed random variables under sublinear expectation space is studied.By moment inequality and truncation methods,we establish the equivalent conditions of complete convergence for weighted sums of sequences of independent,identically distributed random variables under sublinear expectation space.The results complement the corresponding results in probability space to those for sequences of independent,identically distributed random variables under sublinear expectation space. 展开更多
关键词 complete convergence weighted sums i.i.d.random variables sublinear expectation
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On shape coexistence and possible shape isomers of nuclei around^(172)Hg
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作者 Xin Guan Jing Guo +2 位作者 Qi-Wen Sun Bożena Nerlo-Pomorska Krzysztof Pomorski 《Nuclear Science and Techniques》 2025年第7期191-203,共13页
This study explores the phenomenon of shape coexistence in nuclei around^(172)Hg,with a focus on the isotopes^(170)Pt,^(172)Hg,and^(174)Pb,as well as the^(170)Pt to^(180)Pt isotopic chain.Utilizing a macro-microscopic... This study explores the phenomenon of shape coexistence in nuclei around^(172)Hg,with a focus on the isotopes^(170)Pt,^(172)Hg,and^(174)Pb,as well as the^(170)Pt to^(180)Pt isotopic chain.Utilizing a macro-microscopic approach that incorporates the Lublin-Strasbourg Drop model combined with a Yukawa-Folded potential and pairing corrections,we analyze the potential energy surfaces(PESs)to understand the impact of pairing interaction.For^(170)Pt,the PES exhibited a prolate ground state,with additional triaxial and oblate-shaped isomers.In^(172)Hg,the ground-state deformation transitions from triaxial to oblate with increasing pairing interaction,demonstrating its nearlyγ-unstable nature.Three shape isomers(prolate,triaxial,and oblate)were observed,with increased pairing strength leading to the disappearance of the triaxial isomer.^(174)Pb exhibited a prolate ground state that became increasingly spherical with stronger pairing.While shape isomers were present at lower pairing strengths,robust shape coexistence was not observed.For realistic pairing interaction,the ground-state shapes transitioned from prolate in^(170)Pt to a coexistence ofγ-unstable and oblate shapes in^(172)Hg,ultimately approaching spherical symmetry in^(174)Pb.A comparison between Exact and Bardeen-Cooper-Schrieffer(BCS)pairing demonstrated that BCS pairing tends to smooth out shape coexistence and reduce the depth of the shape isomer,leading to less pronounced deformation features.The PESs for even-even^(170)-180 Pt isotopes revealed significant shape evolution.^(170)Pt showed a prolate ground state,whereas^(172)Pt exhibited both triaxial and prolate shape coexistence.In^(174)Pt,the ground state was triaxial,coexisted with a prolate minimum.For^(176)Pt,aγ-unstable ground state coexists with a prolate minimum.By 178 Pt and 180Pt,a dominant prolate minimum emerged.These results highlight the role of shape coexistence andγ-instability in the evolution of nuclear structure,especially in the mid-shell region.These findings highlight the importance of pairing interactions in nuclear deformation and shape coexistence,providing insights into the structural evolution of mid-shell nuclei. 展开更多
关键词 Macro-micro-model shape coexistence shape isomers Exact and BCS pairing solutions
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