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基于Bootstrap-GA-ELM算法的清香型白酒发酵过程酒醅淀粉和水分含量区间预测模型
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作者 张贵宇 向星睿 +3 位作者 张磊 王怡博 严俊 张云龙 《现代食品科技》 北大核心 2026年第3期211-222,共12页
针对清香型白酒发酵过程酒醅淀粉和水分含量信息难以获取的困境,且传统点预测模型仅提供单一预测值而难以量化结果的可靠度的问题,提出一种发酵过程酒醅淀粉和水分含量区间预测模型。首先,从黄水理化参数和酒醅温度等易测潜在解释变量中... 针对清香型白酒发酵过程酒醅淀粉和水分含量信息难以获取的困境,且传统点预测模型仅提供单一预测值而难以量化结果的可靠度的问题,提出一种发酵过程酒醅淀粉和水分含量区间预测模型。首先,从黄水理化参数和酒醅温度等易测潜在解释变量中,通过相关系数、最小角回归(LARS)综合分析确定酒醅淀粉和水分预测模型的输入参数。其次,通过遗传算法(GA)优化极限学习机(ELM)的隐层权值和阈值,建立精度较高的酒醅淀粉和水分点预测模型。最后,通过4种不同自助法(Bootstrap)对点预测结果、系统误差以及随机误差进行估计,以此构建不同置信度下的酒醅淀粉和水分含量预测区间。结果表明,在99%置信度下,基于Residual Bootstrap方法建立的区间预测模型效果最好,在酒醅淀粉和水分测试集上,点预测的判定系数(R^(2))和均方根误差(RMSE)分别为0.9989、0.1091,0.9203、0.8021,预测区间的区间覆盖率(PICP)和平均预测区间宽度(MPIW)分别为100%、0.7280%,100%、4.3399%。该研究可对清香型白酒发酵过程酒醅淀粉和水分含量进行可靠预测,为白酒生产指导和发酵过程透明化提供参考。 展开更多
关键词 酒醅 淀粉 水分 黄水 相关性 点预测 区间预测 bootstrap方法
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Hyponormal Block Toeplitz Operators on the Weighted Bergman Space with Circulant Symbols
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作者 FU Guangyang ZHOU Jiang 《数学进展》 北大核心 2026年第1期183-191,共9页
In this paper,we present a necessary and sufficient condition for hyponormal block Toeplitz operators T on the vector-valued weighted Bergman space with symbolsΦ(z)=G^(*)(z)+F(z),where F(z)=∑^(N)_(i)=1 A_(i)z^(i)and... In this paper,we present a necessary and sufficient condition for hyponormal block Toeplitz operators T on the vector-valued weighted Bergman space with symbolsΦ(z)=G^(*)(z)+F(z),where F(z)=∑^(N)_(i)=1 A_(i)z^(i)and G(z)=∑^(N)_(i)=1 A_(−i)z^(i),A_(i)ae culants. 展开更多
关键词 block Toeplitz operator hyponormal weighted Bergman space CIRCULANT COMMUTATOR
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乳腺癌TOMO计划设计及Block的应用方式研究
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作者 姜亚洲 杨潍铭 +1 位作者 王俭 李舰波 《生物医学工程与临床》 2026年第2期168-173,共6页
目的利用螺旋断层放射治疗(TOMO)计划系统制定乳腺癌保乳术后放射治疗计划,比较Block不同设计方法和径照功能对靶区和危及器官(OAR)剂量的影响。方法选择2024年2月至2025年2月宁波明州医院左侧乳腺癌保乳术后放射治疗女性患者15例,年龄3... 目的利用螺旋断层放射治疗(TOMO)计划系统制定乳腺癌保乳术后放射治疗计划,比较Block不同设计方法和径照功能对靶区和危及器官(OAR)剂量的影响。方法选择2024年2月至2025年2月宁波明州医院左侧乳腺癌保乳术后放射治疗女性患者15例,年龄34~66岁,平均年龄52岁;经病理明确诊断为左侧乳腺癌,其中病理分期TNMⅠ期4例,TNMⅡ期11例。基于TOMO计划系统为每例患者制定3种TOMO计划,第一种计划设计过程中应用了半挡Direction Block(DB)模式,第二种计划应用全挡Complete Block(CB)模式,第三种应用螺旋断层径照射(TD)模式制作计划;比较3种计划的剂量参数,包括靶区的适形度指数(HI)、均匀度指数(CI)、平均剂量、最大剂量;肺、心脏、健侧乳腺及脊髓等OAR剂量差异。结果在靶区剂量方面,DB组和CB组均具有较优异的均匀性和适形性,对比TD组计划差异有统计学意义(CI:0.861±0.041 vs 0.741±0.047、0.871±0.041 vs 0.741±0.047;HI:1.036±0.006 vs 1.052±0.007、1.037±0.004 vs 1.052±0.007)(P<0.05);OAR剂量方面,CB组计划的左肺V_(5)、V_(20)、D_(mean)和心脏V_(10)、V_(20)、D_(mean)均明显优于其他两组,差异均有统计学意义(P<0.05)。比较脊髓的最大剂量(D_(max)),CB组和TD组相对DB组较低,差异有统计学意义[(1.47±1.48)Gy vs(8.66±2.89)Gy、(0.46±0.13)Gy vs(8.66±2.89)Gy](P<0.05)。TD组计划的右肺V_(5),右侧乳腺平均剂量优于DB、CB两组,差异均有统计学意义[V_(5):(0.36±0.48)%vs(17.32±3.47)%、(0.36±0.48)%vs(10.66±4.10)%;右侧乳腺平均剂量:(1.53±0.88)Gy vs(6.79±1.41)Gy、(1.53±0.88)Gy vs(4.89±0.99)Gy](P<0.05)。但TD组心脏V_(10)、V_(10)较DB组、CB组计划高[V_(10):(12.39±4.39)%vs(9.72±5.03)%、(12.39±4.39)%vs(5.09±1.13)%;V_(10):(6.68±4.17)%vs(2.35±1.38)%、(6.68±4.17)%vs(1.47±0.78)%]。时间方面,CB组治疗时间最长,与DB组、TD组差异均有统计学意义[(15.18±2.31)min vs(9.68±1.43)min、(15.18±2.31)min vs(9.88±3.15)min](P<0.05)。结论针对左侧乳腺癌的3种计划比较,DB相对无明显优势,CB的优势表现在能明显降低患侧肺和心脏、脊髓的受量,TD则对保护对侧肺、乳腺能起更好的效果,但CB治疗时间较长,TD靶区适形性均匀性较差,可根据患者实际情况选择计划方式。 展开更多
关键词 螺旋断层放射治疗 block 乳腺癌 剂量学 断层径照
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Enhancing the performance of AlGaN deep-ultraviolet laser diodes without an electron blocking layer by using a thin undoped Al_(0.8)Ga_(0.2)N strip layer structure
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作者 SANG Xi-en WANG Fang +1 位作者 LIU Jun-jie LIU Yu-huai 《中国光学(中英文)》 北大核心 2026年第2期421-433,共13页
AlGaN-based deep-ultraviolet(DUV)laser diodes(LDs)face performance challenges due to elec-tron leakage and poor hole injection which is often worsened by polarization effects from conventional elec-tron blocking layer... AlGaN-based deep-ultraviolet(DUV)laser diodes(LDs)face performance challenges due to elec-tron leakage and poor hole injection which is often worsened by polarization effects from conventional elec-tron blocking layers(EBLs).To overcome these limitations,we propose an EBL-free DUV LD design incor-porating a 1-nm undoped Al_(0.8)Ga_(0.2)N thin strip layer after the last quantum barrier.Using PICS3D simula-tions,we evaluate the optical and electrical characteristics.Results show a significant increase in effective electron barrier height(from 158.2 meV to 420.7 meV)and a reduction in hole barrier height(from 149.2 meV to 62.8 meV),which enhance hole injection and reduce electron leakage.The optimized structure(LD3)achieves a 14%increase in output power,improved slope efficiency(1.85 W/A),and lower threshold current.This design also reduces the quantum confined Stark effect and forms dual hole accumulation regions,im-proving recombination efficiency. 展开更多
关键词 ALGAN deep ultraviolet laser diodes undoped thin strip structure without an electron blocking layers
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A case report with the progression from atrial fibrillation to complete AV block, heart failure and electrical storm
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作者 Shi-Xing LI Xiang-Min SHI +1 位作者 Jian LI Chuang ZHANG 《Journal of Geriatric Cardiology》 2026年第1期65-68,共4页
When patients initially present with atrial fibrillation along with an enlarged heart and heart failure, followed by atrioventricular block, it's essential to consider genetic factors.^([1])Genetic testing can off... When patients initially present with atrial fibrillation along with an enlarged heart and heart failure, followed by atrioventricular block, it's essential to consider genetic factors.^([1])Genetic testing can offer crucial diagnostic evidence, aiding in prognosis assessment and the adoption of appropriate treatment strategies. 展开更多
关键词 heart failure atrial fibrillation enlarged heart atrioventricular block genetic factors genetic testing adoption appropriate treatment strategies complete av block prognosis assessment
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Engineering repairable nanoporous functional coatings on arbitrary substrates by manipulating phase behaviors of block copolymers
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作者 Jiemei Zhou Xiang Ying +3 位作者 Daiwen Li Mingjie Wei Xiangyue Ye Yong Wang 《Chinese Journal of Chemical Engineering》 2026年第1期36-46,共11页
Nanoporous polymers are extensively coated on various substrates to deliver optical,permselective,or other functions.However,it remains desired to fast produce uniform nanoporous polymer coatings on substrates with co... Nanoporous polymers are extensively coated on various substrates to deliver optical,permselective,or other functions.However,it remains desired to fast produce uniform nanoporous polymer coatings on substrates with complex surfaces.Herein,by manipulating the interactions between block copolymers and selective solvents,we prepare repairable nanoporous polymers on arbitrary substrates.This is realized by an extremely simple sequential coating process:sequential coating of block copolymers and their swelling agents on substrate surfaces.The swelling agents are comprised of two solvents that swell the constituent blocks of the copolymers to different degrees,rapidly producing polymer coatings with uniform,interconnected,sub-50 nm pores.This sequential coating process is able to conformally build nanoporous polymers on nonplanar substrates with large lateral sizes and complex surface features,and also to in situ repair defects arising during usages.We further demonstrate that the nanoporous coatings show excellent antireflective and membrane separation performances.This sequential coating process is dictated by polymer–solvent interactions,and is expected to find applications in diverse fields for its simplicity,adaptability,and the capability to produce well-defined nanoporosities. 展开更多
关键词 Nanoporous coating block copolymers Selective swelling Polymer-solvent interactions ANTIREFLECTION
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Engineering stimuli-responsive block copolymers for multimodal bioimaging
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作者 Lizhuang Zhong Ming Liu +3 位作者 Shilong Su Dongxin Zeng Jing Hu Zhiqian Guo 《Chinese Chemical Letters》 2026年第1期116-124,共9页
The diagnostic efficacy of contemporary bioimaging technologies remains constrained by inherent limitations of conventional imaging agents,including suboptimal sensitivity,off-target biodistribution,and inherent cytot... The diagnostic efficacy of contemporary bioimaging technologies remains constrained by inherent limitations of conventional imaging agents,including suboptimal sensitivity,off-target biodistribution,and inherent cytotoxicity.These limitations have catalyzed the development of intelligent stimuli-responsive block copolymers-based bioimaging agents,which was engineered to dynamically respond to endogenous biochemical cues(e.g.,p H gradients,redox potential,enzyme activity,hypoxia environment) or exogenous physical triggers(e.g.,photoirradiation,thermal gradients,ultrasound(US)/magnetic stimuli).Through spatiotemporally controlled structural transformations,stimuli-responsive block copolymers enable precise contrast targeting,activatable signal amplification,and theranostic integration,thereby substantially enhancing signal-to-noise ratios of bioimaging and diagnostic specificity.Hence,this mini-review systematically examines molecular engineering principles for designing p H-,redox-,enzyme-,light-,thermo-,and US/magnetic-responsive polymers,with emphasis on structure-property relationships governing imaging performance modulation.Furthermore,we critically analyze emerging strategies for optical imaging,US synergies,and magnetic resonance imaging(MRI).Multimodal bioimaging has also been elaborated,which could overcome the inherent trade-offs between resolution,penetration depth,and functional specificity in single-modal approaches.By elucidating mechanistic insights and translational challenges,this mini-review aims to establish a design framework of stimuli-responsive block copolymersbased for high fidelity bioimaging agents and accelerate their clinical translation in precise diagnosis and therapy. 展开更多
关键词 STIMULI-RESPONSIVE block copolymers Molecular engineering Multimodal bioimaging Diagnosis and therapy
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ResghostNet:Boosting GhostNet with Residual Connections and Adaptive-SE Blocks
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作者 Yuang Chen Yong Li +2 位作者 Fang Lin Shuhan Lv Jiaze Jiang 《Computers, Materials & Continua》 2026年第2期1524-1541,共18页
Aiming at the problem of potential information noise introduced during the generation of ghost feature maps in GhostNet,this paper proposes a novel lightweight neural network model called ResghostNet.This model constr... Aiming at the problem of potential information noise introduced during the generation of ghost feature maps in GhostNet,this paper proposes a novel lightweight neural network model called ResghostNet.This model constructs the Resghost Module by combining residual connections and Adaptive-SE Blocks,which enhances the quality of generated feature maps through direct propagation of original input information and selection of important channels before cheap operations.Specifically,ResghostNet introduces residual connections on the basis of the Ghost Module to optimize the information flow,and designs a weight self-attention mechanism combined with SE blocks to enhance feature expression capabilities in cheap operations.Experimental results on the ImageNet dataset show that,compared to GhostNet,ResghostNet achieves higher accuracy while reducing the number of parameters by 52%.Although the computational complexity increases,by optimizing the usage strategy of GPU cachememory,themodel’s inference speed becomes faster.The ResghostNet is optimized in terms of classification accuracy and the number of model parameters,and shows great potential in edge computing devices. 展开更多
关键词 Residual connections adaptive-SE blocks lightweight neural network GPU memory usage
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The Magic of Organocatalytic Synergism in Switchable Polymerization:One-pot Synthesis of Block Copolymers with Programmable Sequences and Compositions
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作者 Shuai-Shuai Zhu Mao-Ji Zhao +1 位作者 Ying-Jie Yuan Yong Wang 《Chinese Journal of Polymer Science》 2026年第1期68-78,I0010,共12页
Switchable polymerization is emerging as a powerful tool to construct block copolymers directly from mixtures of monomers.However,current achievements typically iterate between two polymerization cycles to afford prod... Switchable polymerization is emerging as a powerful tool to construct block copolymers directly from mixtures of monomers.However,current achievements typically iterate between two polymerization cycles to afford products with fixed sequences and compositions.Herein,we report the triethylborane/1,8-diazabicyclo[5.4.0]undec-7-ene(Et_3B/DBU)pair-mediated four-component switchable polymerization of propylene oxide(PO),CO_(2),phthalic anhydride(PA),and racemic lactide(rac-LA),which enables the on-demand synthesis of four different block copolymers,i.e.,poly(propylene phthalate)-b-polylactide(PPE-b-PLA),PPE-b-PLA-b-poly(propylene carbonate)(PPC),PPE-b-PPC-b-PLA,and PPE-b-PPCb-poly(propylene oxide)(PPO),through rationally modulating the Lewis pair(LP)ratio.Core to this protocol is that increasing the loading of Et_(3)B accelerates the ring-opening of PO while impeding the reactivity of rac-LA,thus allowing for fine-tuning of the thermodynamic and kinetic of the switchable polymerization.Therefore,the four polymerization cycles involving PO/PA ring-opening copolymerization(ROCOP),PO/CO_(2) ROCOP,rac-LA ring-opening polymerization(ROP),and PO ROP can be connected and discriminated in precisely programmed manners. 展开更多
关键词 Switchable polymerization Organic Lewis pair block copolymers Ring-opening copolymerization Multicomponent reaction
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Optimal orthogonal block designs for threecomponent symmetric general blending models in mixture experiment
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作者 Jiawei Bao Yu Tang 《Statistical Theory and Related Fields》 2026年第1期117-134,共18页
In mixture experiments,the observed response is determined by the relative proportions of the components,consequently rendering the experimental region a simplex.This paper focuses primarily on the optimal designs of ... In mixture experiments,the observed response is determined by the relative proportions of the components,consequently rendering the experimental region a simplex.This paper focuses primarily on the optimal designs of mixture experiments that involve process variables.Prior research has extensively delved into optimal orthogonal block designs for some classic mixture models with process variables.Based on the framework of general blending models,this paper proposes a class of symmetric linear mixture models,which can be regarded as a generalization of many existing ones.Under the orthogonal blocking conditions,orthogonal block designs are devised through Latin squares in the presence of process variables.TheD-,A-,and E-optimality criteria are utilized to obtain optimal designs at the boundary of the simplex in the case of 3 components.As the values of the exponents change,numerically derived optimal design points are presented to illustrate the pattern of their variations,and to verify the consistency of the results with previous research on some specific symmetric general blending models. 展开更多
关键词 Mixture experiments general blending models optimal designs orthogonal Latin squares block designs
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Evaluation of bonded block models as a tool for support design in underground coal mines
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作者 Sankhaneel Sinha Gabriel Walton 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第3期1755-1767,共13页
The failure and collapse of coal pillar ribs represent a significant hazard in the mining industry,with the associated risk of fatalities and injuries anticipated to rise as mining operations advance to greater depths... The failure and collapse of coal pillar ribs represent a significant hazard in the mining industry,with the associated risk of fatalities and injuries anticipated to rise as mining operations advance to greater depths.The development of support guidelines through an enhanced understanding of pillar damage and rock–support interaction mechanisms is crucial to resolving this issue.Bonded block models(BBMs)represent a convenient tool for this purpose,as they can reasonably reproduce the rock fracturing process;however,it is not known to what extent this modeling technique can be applied to simulate pillar failure mechanisms and support interaction in anisotropic rock masses,such as coal.To bridge this gap in research,hypothetical coal pillar BBMs of different width-to-height ratios were developed and calibrated to match Mark–Bieniawski's pillar strength equation,along with a few other attributes from the literature(stress levels at the edge of pillars and the transition from brittle to strain-hardening behavior with increasing width-to-height ratio).Elongated blocks were employed to capture the anisotropic behavior of coal mass.With the reliability of the model established,a few different support patterns were evaluated to ensure that the outputs are broadly consistent with expectations.Finally,simulations of roadway development and additional mining activities were completed considering geo-mining conditions representative of underground coal mines in the USA.The good consistency between model response and expected behaviors per field observation demonstrates the potential of BBMs to be used as a support design tool. 展开更多
关键词 Bonded block model(BBM) Ground control Coal mining Anisotropic rock Support design
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Slope rockbolting using key block theory:Force transfer and artificial intelligence-assisted multi-objective optimisation
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作者 Jessica Ka Yi Chiu Charlie Chunlin Li +1 位作者 Ole Jakob Mengshoel Vidar Kveldsvik 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第1期73-91,共19页
This paper presents a novel artificial intelligence(AI)-assisted two-stage method for optimising rock slope stability by integrating advanced 3D modelling with rock support design,aiming at minimising risks,material u... This paper presents a novel artificial intelligence(AI)-assisted two-stage method for optimising rock slope stability by integrating advanced 3D modelling with rock support design,aiming at minimising risks,material usage,and costs.In the first stage,an extended key block analysis identifies key blocks and key block groups,accounting for progressive failure and force interactions.The second stage uses AI algorithms to optimise rockbolting design,balancing stability,cost,and material use.The most efficient algorithms include the multi-objective tree-structured Parzen estimator(MOTPE)and non-dominated sorting genetic algorithms(NSGA-II and NSGA-III).Applied to the Larvik rock slope,the optimised solution uses 18 pre-tensioned cablebolts,providing 13.2 MN of active force and achieving a factor of safety of 1.31 while reducing the average anchorage length by approximately 16%compared to traditional design.The AI-assisted approach also reduces computation time by over 90%compared to Quasi-Monte Carlo(QMC)methods,demonstrating its efficiency for small-scale civil engineering projects and large-scale mining operations.The developed tool is practical,compatible with Building Information Modelling(BIM),and ready for engineering implementation,supporting sustainable and cost-effective rock slope stabilisation.While the method is largely automated,professional judgement remains crucial for verifying ground conditions and selecting the final solution.Future work will focus on integrating data uncertainties,addressing complex block deformation mechanisms,refining optimisation objectives,and improving the performance of multi-objective optimisation for slope rockboling applications to further enhance the method's versatility. 展开更多
关键词 Rock anchoring Slope stability 3D modelling Key block Parametric design Bio-inspired artificial intelligence(AI)
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Preparation of low-expansion high-performance Si-C composites based on porous advantage of detoxified and purified waste cathode graphite blocks
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作者 Guoqing Yu Mingzhuang Xie +4 位作者 Zhihao Zheng Zegang Wu Yi Wang Hongliang Zhao Fengqin Liu 《International Journal of Minerals,Metallurgy and Materials》 2026年第2期716-726,共11页
Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphi... Waste graphitization cathode carbon blocks are a type of hazardous solid waste generated during the aluminum electrolysis process,and their proper disposal is a key step in the resource utilization of discarded graphite.This study utilizes the porous“defect advantage”of a cathode carbon block matrix to prepare silicon-doped and asphalt-coated detoxified and purified waste graphitization cathode carbon blocks for use as high-performance silicon/carbon composite anode materials.The results show that the uniformly silicondoped silicon/carbon composite material features a unique amorphous carbon-encapsulated“locked silicon”structure,which effectively addresses issues such as cathode volume expansion,excessive growth of the solid electrolyte interphase(SEI)film,and poor electrical contact between active materials.Consequently,electrochemical performance is enhanced.After assembly in a half-cell,the PSCC/10%Si@C(purified waste graphitization cathode carbon/10%Si@C)material exhibits optimal electrochemical stability,with an initial charging specific capacity of 514.5 mAh/g at 0.1 C(1 C=170 mA/g)and a capacity retention rate of 95.1%after 100 cycles.At a charge rate of 2.0 C,a specific capacity of 216.9 mAh/g is achieved.This technology provides a new pathway for the economical and high-value utilization of waste cathode carbon blocks and the development of low-cost,high-performance anode materials. 展开更多
关键词 waste graphitization cathode carbon blocks defect advantage silicon/carbon anode materials hazardous waste resource util-ization
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Star-shaped Block Copolymers of Poly-2-alkyl-5,6-dihydrooxazines:Synthesis,Conformational Characteristics,Thermoresponsiveness and Complexation with Curcumin
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作者 Tatyana U.Kirila Serafim V.Rodchenko +2 位作者 Nina D.Kozina Andrey V.Tenkovtsev Alexander P.Filippov 《Chinese Journal of Polymer Science》 2026年第2期423-436,I0012,共15页
Star-shaped six-arm polymers with hexaaza[2_(6)]orthoparacyclophane core and arms of block copolymers of poly-2-ethyl-5,6-dihydrooxazine with poly-2-isopropyl-5,6-dihydrooxazine were synthesized successfully using cat... Star-shaped six-arm polymers with hexaaza[2_(6)]orthoparacyclophane core and arms of block copolymers of poly-2-ethyl-5,6-dihydrooxazine with poly-2-isopropyl-5,6-dihydrooxazine were synthesized successfully using cationic ring-opening polymerization.The ratio of blocks,the order of their attachment to the core,and arm length were varied.Conformation of synthesized stars was determined by methods of molecular hydrodynamics and optics.It has been shown that star-shaped molecules were characterized by high intramolecular density,and the arm folding increased with their lengthening.The influence of the structure of block copolymers and their molar mass on the critical micelle concentration has been established.Complexes of synthesized star-shaped block copolymers with curcumin were obtained and the efficient binding of curcumin to polymer molecules was demonstrated.The behavior of the aqueous solutions of the prepared polymer stars and their complexes with curcumin was investigated by light scattering and turbidimetry methods.The influence of the structure and molar mass of star polymers on their thermoresponsiveness and the phase separation temperatures in aqueous solutions was analyzed.A slight increase in the phase separation temperature was found on passage from polymer solutions to solutions of polymer complexes with hydrophobic curcumin. 展开更多
关键词 Thermoresponsive star-shaped polymers block copolymer of poly-2-alkyl-5 6-dihydrooxazine Aqueous solutions Complex of polymer with curcumin Phase separation
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基于Bootstrap-DEA模型的陕西省三级综合医院技术效率实证研究
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作者 张洁铭 陈鹏岗 《中国卫生信息管理杂志》 2026年第1期168-176,共9页
目的在公立医院高质量发展的政策背景下,探究陕西省三级综合医院技术效率并分析其影响因素,为完善政策和保障医院高质量发展提供决策参考。方法选取陕西省48所综合三级医院作为研究对象,运用Max DEA软件中的Bootstrap模块测算纠偏前后... 目的在公立医院高质量发展的政策背景下,探究陕西省三级综合医院技术效率并分析其影响因素,为完善政策和保障医院高质量发展提供决策参考。方法选取陕西省48所综合三级医院作为研究对象,运用Max DEA软件中的Bootstrap模块测算纠偏前后医院的相对效率值,选取的投入指标包括职工总数和实际开放床位数,产出指标包括年诊疗人次数、年出院人次数和病床使用率。运用Tobit模型分析技术效率的影响因素,选取有关医院高质量发展的医院运行管理指标,包括医院类型、城市类型、资源配置、工作负荷和工作效率,对医院的技术效率影响因素进行回归分析。结果陕西省48所综合三级医院间职工数和床位数差异较大,采用Bootstrap纠偏后,所有三级医院的技术效率得分均降低,纠偏前得分(均值0.767)高于纠偏后得分(均值0.643)。公立医院的纠偏后技术效率得分(均值0.654)高于民营医院的得分(均值0.566),但差异无统计学意义(P=0.327);位于省会城市的医院纠偏后技术效率得分(均值0.615)低于非省会城市的得分(均值0.666),但差异无统计学意义(P=0.180)。Tobit模型分析显示,资源配置维度的在职职工数与医院技术效率得分呈负相关,工作负荷与工作效率维度的总诊疗人次数、病床使用率和医院技术效率得分呈正相关。结论陕西省综合三级医院运行效率尚未达到最优,建议三级医院加强精细化管理,着重提高三级公立医院的总诊疗人次、加强医院床位管理、培育优秀临床人才。 展开更多
关键词 bootstrap-DEA模型 技术效率 陕西省 TOBIT模型 医院管理 医院信息挖掘
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基于Block-Bootstrap仿真技术的基金选股能力 被引量:5
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作者 许宁 刘志新 柴文义 《系统工程》 CSCD 北大核心 2009年第3期46-52,共7页
传统评价基金选股能力方法通常假定残差服从正态分布,但现实数据往往不满足此假设条件,非参数Block-Bootstrap仿真技术可以对此修正。本文以2004年1月至2008年4月1我国153支开放式偏股型基金月度数据为样本,对基金选股能力进行研究。结... 传统评价基金选股能力方法通常假定残差服从正态分布,但现实数据往往不满足此假设条件,非参数Block-Bootstrap仿真技术可以对此修正。本文以2004年1月至2008年4月1我国153支开放式偏股型基金月度数据为样本,对基金选股能力进行研究。结果表明利用Block-Bootstrap方法剔除掉"伪"选股能力基金后,确实存在具备显著选股能力的基金。 展开更多
关键词 开放式基金 选股能力 block-bootstrap
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B股相对于A股的市场投资价值研究——基于均值-方差张成与Block-Bootstrap模拟的分析 被引量:4
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作者 李传乐 王美今 《数理统计与管理》 CSSCI 北大核心 2010年第5期899-908,共10页
本文采用均值-方差张成的方法研究B股相对于A股的市场投资价值。首先,通过MonteCarlo模拟研究了均值-方差张成检验的小样本性质,发现模型的GMM-Wald检验存在显著的小样本偏倚,故采用基于残差再抽样的Block-Bootstrap方法模拟Wald统计量... 本文采用均值-方差张成的方法研究B股相对于A股的市场投资价值。首先,通过MonteCarlo模拟研究了均值-方差张成检验的小样本性质,发现模型的GMM-Wald检验存在显著的小样本偏倚,故采用基于残差再抽样的Block-Bootstrap方法模拟Wald统计量的分布以克服小样本偏倚的影响;接着分别对A、B股构造规模资产组合作为其资产的代理变量,利用模拟的Wald统计量进行实证研究,结果发现:B股未向国内居民开放前,相对于A股具有投资价值,向国内居民开放后,相对于A股不再具有投资价值。文章最后对B股投资价值的这种变化作出了经济解释,并提出相应的政策建议。 展开更多
关键词 张成资产 规模组合 Mote CARLO模拟 block-bootstrap方法
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Block Bootstrap方法在季节时间序列单位根检验中的应用 被引量:1
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作者 赵春艳 严方笠 《统计与决策》 CSSCI 北大核心 2019年第23期17-22,共6页
传统的参数类检验方法存在参数极限分布非标准、参数解析式推导烦琐、差分平稳后序列均值难估计等问题。为了避免上述问题,文章改进季节时间序列单位根检验方法,首先基于非参数Block Bootstrap方法提出BB-HEGY检验统计量,并给出临界值;... 传统的参数类检验方法存在参数极限分布非标准、参数解析式推导烦琐、差分平稳后序列均值难估计等问题。为了避免上述问题,文章改进季节时间序列单位根检验方法,首先基于非参数Block Bootstrap方法提出BB-HEGY检验统计量,并给出临界值;其次,通过比较BB-HEGY统计量和传统的HEGY统计量的有限样本性质,发现BB-HEGY统计量具有更好功效和检验水平,尤其在季节频率上有更明显的优势;最后,通过对中国宏观经济指标的实证检验,进一步证明BB-HEGY检验统计量的优越性。 展开更多
关键词 季节性单位根 block bootstrap 检验水平 功效
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Twin-block矫治器对不同舌位下颌后缩患者上气道的改善作用
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作者 周志翀 《医师在线》 2026年第1期87-90,共4页
目的探讨静息舌位是否会影响Twin-block矫治器对下颌后缩患者上气道的扩张作用。方法选取2021年1月至2022年10月于上海市静安区牙病防治所正畸科就诊并使用Twin-block矫治器行功能矫治(以下颌前导为主)的40例患者作为研究对象。所有患... 目的探讨静息舌位是否会影响Twin-block矫治器对下颌后缩患者上气道的扩张作用。方法选取2021年1月至2022年10月于上海市静安区牙病防治所正畸科就诊并使用Twin-block矫治器行功能矫治(以下颌前导为主)的40例患者作为研究对象。所有患者均行锥形束CT(CBCT)检查,经三维重建后获取正中矢状面图像。根据舌体与上腭的位置关系分为两组:舌体与上腭紧密贴合者为舌高位组,舌体与上腭分离者为舌低位组,每组20例。观察两组患者的气道二维测量(最小横截面积)及气道三维测量(气道体积)值及变化量。结果舌低位组治疗后鼻咽段、腭咽段最小横截面积、体积及总体积均较治疗前显著增加(P<0.05);舌咽段最小横截面积、体积治疗前后比较,差异无统计学意义(P>0.05)。舌高位组治疗后鼻咽段、腭咽段最小横截面积、体积及总体积均较治疗前显著增加(P<0.05);舌咽段最小横截面积、体积治疗前后比较,差异无统计学意义(P>0.05)。组间比较显示,舌高位组腭咽段最小横截面积、体积的变化量显著大于舌低位组(P<0.05);两组鼻咽段及舌咽段最小横截面积、体积及总体积变化量比较,差异均无统计学意义(P>0.05)。结论Twin-block矫治器对下颌后缩患者上气道有扩张作用,且舌高位组患者较舌低位组患者的腭咽段气道扩张效果更为明显。 展开更多
关键词 TWIN-block矫治器 下颌后缩 气道体积 儿童
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Block Bootstrap面板单位根检验理论方法 被引量:1
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作者 胥莉 《统计与决策》 CSSCI 北大核心 2015年第14期26-30,共5页
Block bootstrap面板单位根检验是一种区别于且优于传统基于渐近理论推断的面板单位根检验方法,不仅比渐近检验更稳健,还能应用于更一般的截面相依的面板数据,是有效分析跨国或跨地区面板数据的一种更可靠的检验方法。文章阐述block boo... Block bootstrap面板单位根检验是一种区别于且优于传统基于渐近理论推断的面板单位根检验方法,不仅比渐近检验更稳健,还能应用于更一般的截面相依的面板数据,是有效分析跨国或跨地区面板数据的一种更可靠的检验方法。文章阐述block bootstrap面板单位根检验的理论、方法及其应用,并将其用于国内尚待系统研究的失业回滞现象。基于我国28省21年的面板数据,检验我国劳动力市场上是否存在失业回滞现象,结果显示,我国存在显著的失业回滞现象。 展开更多
关键词 block bootstrap 面板单位根检验 失业回滞
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