检索结果-南通市图书馆

腹主动脉预置球囊辅助凶险性前置胎盘伴胎盘植入剖宫产的临床应用研究

在线全文

学校读者我要写书评

暂无评论

海南医学 2024年第6期35卷 804-809页

作者：宋瑞香肖飒苗红艳三门峡市中心医院产科河南三门峡472000

目的探讨腹主动脉预置球囊术对凶险性前置胎盘(PPP)伴胎盘植入剖宫产产妇应激反应、凝血功能及母婴结局的影响。方法选取2021年1月至2023年6月三门峡市中心医院收治的62例PPP伴胎盘植入产妇,按照随机数表法分为观察组和对照组各31例。... 详细信息

目的探讨腹主动脉预置球囊术对凶险性前置胎盘(PPP)伴胎盘植入剖宫产产妇应激反应、凝血功能及母婴结局的影响。方法选取2021年1月至2023年6月三门峡市中心医院收治的62例PPP伴胎盘植入产妇,按照随机数表法分为观察组和对照组各31例。两组产妇均行剖宫产术,对照组行髂内动脉预置球囊术,研究组行腹主动脉预置球囊术。比较两组产妇的手术指标、手术前后的应激反应指标[肾上腺素(E)、促肾上腺皮质激素(ACTH)、皮质醇(Cor)、去甲肾上腺素(NE)]、凝血功能[凝血酶原时间(PT)、凝血酶时间(TT)、活化部分凝血活酶时间(APTT)、纤维蛋白原(FIB)]、血红蛋白(Hb)、红细胞压积(HCT)水平,同时比较两组新生儿的相关情况及产妇的子宫切除率和并发症发生率。结果研究组产妇的手术时间、透视耗时、住院时间分别为(111.63±15.59)min、(15.67±3.27)s、(6.04±0.53)d,明显短于对照组的(128.75±20.03)min、(28.96±5.11)s、(6.65±0.74)d,放射剂量、术中与术后24 h出血量、术中输血量分别为(4.21±0.74)mGy、(752.31±153.66)mL、(135.47±20.37)mL、(357.92±32.40)mL,明显少于对照组的(15.63±2.39)mGy、(1026.47±212.52)mL、(328.19±38.92)mL、(950.30±85.61)mL,差异均有统计学意义(P<0.05);术后24 h,研究组产妇的血清Cor、ACTH、E、NE水平明显低于对照组,APTT、TT、PT、FIB、Hb、HCT明显高于对照组,差异均有统计学意义(P<0.05);出生1 min、5 min,研究组新生儿Apgar评分分别为(9.02±0.27)分、(9.52±0.24)分,明显高于对照组的(8.74±0.33)分、(9.13±0.30)分,新生儿窒息率为0,明显低于对照组的19.35%,差异均有统计学意义(P<0.05);研究组产妇的子宫切除率、并发症发生率分别为6.45%、6.45%,明显低于对照组的29.03%、32.26%,差异均有统计学意义(P<0.05)。结论腹主动脉预置球囊可减少PPP伴胎盘植入剖宫术中放射剂量、出血量及输血量,减少应激反应,改善凝血功能,促进术后早期恢复,同时提高手术安全性,改善新生儿分娩结局,降低窒息与子宫切除风险。

关键词：凶险性前置胎盘胎盘植入腹主动脉预置球囊术髂内动脉预置球囊术应激反应凝血功能新生儿情况子宫切除率并发症

Multicolor circularly polarized phosphorescence of axially chiral binuclear platinum(Ⅱ) complexes

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第11期67卷 3757-3766页

作者： Jintong song rui Zeng Hui Xiao Hailiang Ni Zong-xiang Xu Haifeng xiang College of Chemistry and Materials Science Sichuan Normal University Department of Chemistry Southern University of Science and Technology College of Chemistry Sichuan University

D-A charge transfer, including through-bond charge transfer and through-space charge transfer between two different electron donors（D） and electron acceptors（A）, is a fundamental and powerful tool to tune the optical properties of organic dyes. Herein,we demonstrate a unique strategy to tune phosphorescence and circularly polarized luminescence properties of axially chiral binuclear Pt（Ⅱ） complexes through long-range charge transfer, even though these molecules have two totally identical segments on either side of the chiral core. The presence of axial chirality would break not only the symmetry of molecular structure and π-conjugation system but also the symmetry of charge distribution for long-range charge transfer. These binaphthyl-based Pt（Ⅱ）complexes bearing coordinated atoms far away from chiral axis exhibit no Pt-Pt interactions but colorful concentrationdependent phosphorescence with quantum yield up to 86.4% and could be applied as emitters in highly efficient solutionprocessed organic light-emitting diodes to achieve luminance, luminance efficiency, power efficiency, external quantum efficiency, and asymmetry factor up to 8.94 × 10～3cd m-2, 41.9 cd A-1, 18.8 lm W-1, 12.6% and 2.98 × 10-3, respectively. Therefore,the present work affords a new and simple way to utilize the inherently asymmetric advantage of chirality for the design of D-Abased organic dyes.

关键词： Pt(II) complexes organic light-emitting diodes circularly polarized phosphorescence axial chirality

S1-supported Pd@CeO_(2) quasi-core@shell materials as advanced catalysts for selective hydrogenation of furfural

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第3期35卷 493-496页

作者： xiang Chu Lingling Zhang Ke Wang rui Zhang Xiao Wang Shuyan song Hongjie Zhang State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Bare Pd metal nanoparticles invariably suffer from poor selectivity in furfural hydrogenation by forming flat configurations,with the aromatic ring of the substrate molecules parallel to the metal ***,we put forward a promising solution by using CeO_(2)as promoters to modify Pd nanoparticles for modulating the adsorption behaviors of furfural *** achieve the highly-desired ultra-small Pd@CeO_(2)core@shell nanostructure,a“constrained auto-redox”synthesis is developed,in which silicalite-1 supports play the key role of providing their surface as the landing place of PdO_(x)precursors for inhibiting the overgrowth and the *** the best of our knowledge,this is one of the smallest core@shell materials obtained from aqueous *** evaluated as catalysts,Pd@CeO_(2)/S-1 gives 98.9%conversion of furfural with 94.3%selectivity for furfural alcohol in 15 h,which is much better than that of Pd/S-1(88.6%conversion with 44.3%selectively).The DFT simulation reveals a strong interaction between the defects of CeO_(2)and the oxygen atom of the–CHO group in furfural molecules,which benefits the selective hydrogenation occurred in the–CHO group rather than the furan ring.

关键词： Core@shell Palladium Ceria Auto-redox synthesis Hydrogenation

Analysis of pile rows on noise reduction of building vibration caused by subway operation

在线全文

学校读者我要写书评

暂无评论

Yantu Lixue/Rock and Soil Mechanics 2020年 41卷 209-218页

作者： Wu, Yu-Bin song, rui-xiang Wu, Ya-Nan He, Lei Liu, Bi-Ding Beijing Municipal Institute of Labour Protection Beijing 100054 China

With the rapid development of subway construction, the impacts of vibration of neighboring subway and structure-borne noise on building get more and more obvious. Pile rows have gradually become one of the effective methods on controlling the vibration of metro. The vibration isolation mechanism, efficiency of pile rows on site soil environmental vibration and design parameters have been studied relatively mature. However, the controlling effect of pile rows on floor vibration and noise of indoor structure is rarely reported. In this paper, taking the new building near the ground line of throat area in metro depot as an object, on the basis of vibration test of building floor and site soil, the 3D finite element model is applied to systematically study the controlling effect of pile rows on the vibration of building floor and indoor secondary structure noise, and also the parameter impacts. It shows that the configuration location of pile rows and buried depth have obvious impacts on isolating the indoor vibration of buildings and structure-borne noise. The controlling effect is affected by the dynamic characteristics of buildings and floors. The control effect of different floors and rooms differs greatly. It is necessary to carry out special design in engineering application. The results can provide useful information for engineering design of pile rows in controlling the vibration of subway. © 2020, Science Press. All right reserved.

关键词： Piles

Weighted Composition Operators That Preserve Frames On Weighted Hardy Spaces

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第7期40卷 1645-1654页

作者： Ya Li Dong rui Liu Guo xiang Lu School of Mathematical Sciences and LPMC Nankai UniversityTianjin300071P.R.China School of Statistics and Mathematics Zhongnan University of Economics and LawWuhan430073P.R.China

In this paper, we characterize weighted composition operators that preserve frames on the weighted Hardy spaces in the unit disk. In particular, we obtain the symbol properties of the bounded invertible weighted composition operators. Moreover, we establish the equivalence between bounded invertible operators and frame-preserving operators. Furthermore, we show that weighted composition operator preserves frames if and only if it preserves the Riesz bases property. Additionally,we investigate the weighted composition operators that preserve tight or normalized tight frames on the Dirichlet space.

关键词： Weighted composition operators Weighted Hardy spaces frames invertible

Parameterization of height-diameter and crown radius-diameter relationships across the globe

在线全文

学校读者我要写书评

暂无评论

Journal of Plant Ecology 2024年第2期17卷 36-48页

作者： xiang song Jinxu Li Xiaodong Zeng International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China School of Mathematics and Statistics North China University of Water Resources and Electric PowerZhengzhou 450046China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The tree height-diameter at breast height(H-DBH)and crown radius-DBH(CR-DBH)relationships are key for forest carbon/biomass estimation,parameterization in vegetation models and vegetation-atmosphere *** the H-DBH relationship has been widely investigated on site or regional scales,and a few of studies have involved CR-DBH relationships based on plot-level data,few studies have quantitatively verifed the universality of these two relationships on a global *** study evaluated the ability of 29 functions to ft the H-DBH and CR-DBH relationships for six different plant functional types(PFTs)on a global scale,based on a global plant trait *** showed that most functions were able to capture the H-DBH relationship for tropical PFTs and boreal needleleaf trees relatively accurately,but slightly less for temperate PFTs and boreal broadleaf trees(BB).For boreal PFTs,the S-shaped Logistic function ftted the H-DBH relationship best,while for temperate PFTs the Chapman-Richards function performed *** tropical needleleaf trees,the fractional function of DBH satisfactorily captured the H-DBH relationship,while for tropical broadleaf trees,the Weibull function and a composite function of fractions were the best *** CR-DBH,the ftting capabilities of all the functions were comparable for all PFTs except *** Logistic function performed best for two boreal PFTs and temperate broadleaf trees,but for temperate needleleaf trees and two tropical PFTs,some exponential functions demonstrated higher *** work provides valuable information for parameterization improvements in vegetation models and forest feld investigations.

关键词： tree height diameter at breast height crown radius ftting function parameterization vegetation model

A Weakly-Supervised Crowd Density Estimation Method Based on Two-Stage Linear Feature Calibration

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第4期11卷 965-981页

作者： Yong-Chao Li rui-Sheng Jia Ying-xiang Hu Hong-Mei Sun the College of Computer Science and Engineering Shandong University of Science and TechnologyQingdao 266590 the Faculty of Information Science and Engineering Ocean University of ChinaQingdao 266000China the College of Computer Science and Engineering Shandong University of Science and TechnologyQingdao 266590China the College of Computer Science and Engineering Nanjing University of Science and TechnologyNanjing 210000China

In a crowd density estimation dataset,the annotation of crowd locations is an extremely laborious task,and they are not taken into the evaluation *** this paper,we aim to reduce the annotation cost of crowd datasets,and propose a crowd density estimation method based on weakly-supervised learning,in the absence of crowd position supervision information,which directly reduces the number of crowds by using the number of pedestrians in the image as the supervised *** this purpose,we design a new training method,which exploits the correlation between global and local image features by incremental learning to train the ***,we design a parent-child network(PC-Net)focusing on the global and local image respectively,and propose a linear feature calibration structure to train the PC-Net simultaneously,and the child network learns feature transfer factors and feature bias weights,and uses the transfer factors and bias weights to linearly feature calibrate the features extracted from the Parent network,to improve the convergence of the network by using local features hidden in the crowd *** addition,we use the pyramid vision transformer as the backbone of the PC-Net to extract crowd features at different levels,and design a global-local feature loss function(L2).We combine it with a crowd counting loss(LC)to enhance the sensitivity of the network to crowd features during the training process,which effectively improves the accuracy of crowd density *** experimental results show that the PC-Net significantly reduces the gap between fullysupervised and weakly-supervised crowd density estimation,and outperforms the comparison methods on five datasets of Shanghai Tech Part A,ShanghaiTech Part B,UCF_CC_50,UCF_QNRF and JHU-CROWD++.

关键词： Crowd density estimation linear feature calibration vision transformer weakly-supervision learning

Flexible polydimethylsiloxane pressure sensor with micro-pyramid structures and embedded silver nanowires:A novel application in urinary flow measurement

在线全文

学校读者我要写书评

暂无评论

Nanotechnology and Precision Engineering 2024年第3期7卷 1-12页

作者： Ben-song Wang Ang Gao song-Wei Huang Qi-Hong Ning Cheng Zhou Qi-xiang song Da-xiangCui School of Electronic Information and Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Department of Urology Renji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200240China

Flexible pressure sensors are lightweight and highly sensitive,making them suitable for use in small portable devices to achieve precise measurements of tiny *** article introduces a low-cost and easy-fabrication strategy for piezoresistive flexible pressure *** embedding silver nanowires into a polydimethylsiloxane layer with micro-pyramids on its surface,a flexible pressure sensor is created that can detect low pressure (17.3 Pa) with fast response (<20 ms) and high sensitivity (69.6 mA kPa-1).Furthermore,the pressure sensor exhibits a sensitive and stable response to a small amount of water flowing on its *** this basis,the flexible pressure sensor is innovatively combined with a micro-rotor to fabricate a novel urinary flow-rate meter (uroflowmeter),and results from a simulated human urination experiment show that the uroflowmeter accurately captured all the essential shape characteristics that were present in the pump-simulated urination *** ahead,this research provides a new reference for using flexible pressure sensors in urinary flow-rate monitoring.

关键词： Flexible pressure sensor Silver nanowires Portable device Uroﬂowmeter Healthcare

Capacity Market Mechanism Design,Considering Network Optimization and Energy Transition

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2024年第4期10卷 1676-1687页

作者： Nan Shang Yihang song xiang Zhang You Lin China Southern Power Grid Co. Ltd.Guangzhou 510663China Southern Methodist University Junkins 3086251 Airline Road DallasTX 75205US

The coordination of enrgy transition,fixed cost recovery,and sufficient generation supply leads to a new challenge for a traditional capacity market ***,in order to better match network expansion at the same time,it is crucial to redesign the capacity market mechanism considering system *** this paper,a novel capacity market mechanism is proposed considering spot market operations,network expansion,and energy transition,which can minimize the total cost of capacity investment,network expansion,and generation operations,while satisfying the energy transition constraints and topology ***,the capacity market mechanism co-ordinated with spot market operations is illustrated,in which the energy transition and network constraints are ***,a bi-level optimization model is established where the trade organizers minimize the total cost of both investment and operations,subject to the spot power market simultaneously minimizing the local dispatching *** numerical results of a test system show that more economical capacity portfolios can be obtained by constructing reasonable transmission lines,thereby obtaining a more optimal market cost.A detailed multi-scenario simulation is further analyzed to verify the effectiveness of the proposed market mechanism.

关键词： Capacity market energy transition network expansion spot market operation