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On Sentence Complexity in THE TIMES: A Comparative Study of SentenceLength and Sentence Complexity in the News Section and the Sports Section
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作者 赤列德吉 《海外英语》 2014年第15期3-4,共2页
My investigation will serve two purposes. First, I shall investigate the function of the subclauses in the corpus in relation to their complexity, and I shall establish whether there is a correlation between sentence ... My investigation will serve two purposes. First, I shall investigate the function of the subclauses in the corpus in relation to their complexity, and I shall establish whether there is a correlation between sentence length and sentence complexity.Second, I shall analyse the complexity of the subclauses collected from the two sections and compare the results from these sections, focusing on finite subclauses and non-finite subclauses. I hope to be able to point out some differences in style between the news and sports sections concerning the use of subordinate clauses in various syntactic functions in order to examine how the choice of linguistic structures differs in different sections of The Times. 展开更多
关键词 SENTENCE length SENTENCE COMPLEXITY style MARKER t
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The Effective Buckling Length on Numerical Study of Pipe-Sectioned Pier-Pile Integral Steel Structure
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作者 Takayuki Omori Akira Kasai Rei Kohara 《Open Journal of Earthquake Research》 2017年第4期159-167,共9页
Pier-Pile integral structures provide construction works with many environmental and landscape advantages. For example, the space required to construct these structures is smaller than that of other bridges due to the... Pier-Pile integral structures provide construction works with many environmental and landscape advantages. For example, the space required to construct these structures is smaller than that of other bridges due to the footing being removed, meaning that it is not necessity to greatly change the surroundings of these bridges. While there are environmental and landscape advantages, there are also a few demerits for the overall land-scape designs, including demerits in the design of this proposed structure which consists of relatively slender parts. This proposed structure has already been constructed in areas where possibility of a severe earthquake is low. However, some problems that have yet to be examined are related to the use of this proposed structure in areas where earthquakes are frequent. Lacking detailed studies of its behavior during severe earthquakes, it is currently difficult to construct these structures in Japan. Consequently, it is necessary to investigate in detail limited performance about compression and bending moment, and earthquake- resistant performance of these structures in order to resolve these problems. In this paper, It was clarified the relationship between the rigidity of the ground and the effective buckling length by buckling analysis and elasto- plastic finite deformation analysis. Moreover, it was proposed a simplified formula using a proposed characteristic value β and several factors for analysis accuracy. A simplified formula would support to determine the effective buckling length to design the pier using the load-bearing capacity curve based on the slenderness ratio parameter. 展开更多
关键词 Pire-Pile INTEGRAL Steel Structures EFFECTIVE BUCKLING length PIPE section
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Influence of anchorage length and pretension on the working resistance of rock bolt based on its tensile characteristics 被引量:3
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作者 Jucai Chang Kai He +3 位作者 Dongdong Pang Dong Li Chuanming Li Bingjun Sun 《International Journal of Coal Science & Technology》 EI CAS CSCD 2021年第6期1384-1399,共16页
In coal mining roadway support design,the working resistance of the rock bolt is the key factor affecting its maximum support load.Effective improvement of the working resistance is of great significance to roadway su... In coal mining roadway support design,the working resistance of the rock bolt is the key factor affecting its maximum support load.Effective improvement of the working resistance is of great significance to roadway support.Based on the rock bolt’s tensile characteristics and the mining roadway surrounding rock deformation,a mechanical model for calculating the working resistance of the rock bolt was established and solved.Taking the mining roadway of the 17102(3)working face at the Panji No.3 Coal Mine of China as a research site,with a quadrilateral section roadway,the influence of pretension and anchorage length on the working resistance of high-strength and ordinary rock bolts in the middle and corner of the roadway is studied.The results show that when the bolt is in the elastic stage,increasing the pretension and anchorage length can effectively improve the working resistance.When the bolt is in the yield and strain-strengthening stages,increasing the pretension and anchorage length cannot effectively improve the working resistance.The influence of pretension and anchorage length on the ordinary and high-strength bolts is similar.The ordinary bolt’s working resistance is approximately 25 kN less than that of the high-strength bolt.When pretension and anchorage length are considered separately,the best pretensions of the high-strength bolt in the middle of the roadway side and the roadway corner are 41.55 and 104.26 kN,respectively,and the best anchorage lengths are 1.54 and 2.12 m,respectively.The best anchorage length of the ordinary bolt is the same as that of the high-strength bolt,and the best pretension for the ordinary bolt in the middle of the roadway side and at the roadway corner is 33.51 and 85.12 kN,respectively.The research results can provide a theoretical basis for supporting the design of quadrilateral mining roadways. 展开更多
关键词 Working resistance of rock bolt PRETENSION Anchorage length Ordinary bolt High-strength bolt Quadrilateral section roadway
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Analysis of the mass of behind-armor debris generated by RHA subjected to normal penetration of variable cross-section EFP 被引量:4
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作者 Boyang Xing Dongjiang Zhang +7 位作者 Zhenyan Guo Yunhui Hou Rui Guo Rongzhong Liu Liang Chen Hao Zhou Yongliang Yang Jianhua Luo 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2019年第3期390-397,共8页
Analyzing the mass of behind-armor debris (BAD) generated by Rolled Homogeneous Armor (RHA) subjected to normal penetration of variable cross-section Explosively Formed Projectile (EFP) is the purpose of this paper. S... Analyzing the mass of behind-armor debris (BAD) generated by Rolled Homogeneous Armor (RHA) subjected to normal penetration of variable cross-section Explosively Formed Projectile (EFP) is the purpose of this paper. So theoretical analysis, numerical simulation and experimental data are combined to analyze the influence of variable cross-section characteristic on the time history of crater radius. Moreover the relationships between time history of crater radius (as well as mass of BAD) and the thickness of RHA (from 30mm to 70 mm) and the impact velocity of EFP (1650 m/s to 1860 m/s) are also investigated. The results indicate that: 1) being compared to the variable cross-section characteristic is ignored, the theoretical time history of crater radius is in better agreement with the simulation results when the variable cross-section characteristic is considered;2) being compared to the other three conditions of plug, the theoretical mass of BAD is in the best agreement with the simulation results when the shape of plug is frustum of a cone and the angle between generatrix and bottom is 45- and the axial length of mushroom is considered. 展开更多
关键词 Explosively formed PROJECTILE Behind-armor DEBRIS Variable CROSS-section characteristic Shape of plug Axial length of MUSHROOM theoretical model
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Determination of Telomere Length by the Quantitative Fluorescence <i>in Situ</i>Hybridization (Q-FISH) Method
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作者 Junko Aida Naotaka Izumiyama-Shimomura +6 位作者 Ken-ichi Nakamura Naoshi Ishikawa Masanori Terai Yoko Matsuda Shinsuke Aida Tomio Arai Kaiyo Takubo 《American Journal of Analytical Chemistry》 2014年第12期775-783,共9页
Telomeres are nucleoprotein complexes located at the ends of eukaryotic chromosomes and are shorten with aging or various causes. Shortened telomere plays an important role for chromosomal instability in carcinogenesi... Telomeres are nucleoprotein complexes located at the ends of eukaryotic chromosomes and are shorten with aging or various causes. Shortened telomere plays an important role for chromosomal instability in carcinogenesis, or a number of diseases in relation to aging. FISH using peptide-nucleic acid (PNA) probe is suitable for analyzing telomeres, because telomere is a part of DNA molecule and localized in chromosomal end in loop shape structure (T-loop). We introduce our telomere analysis for tissue sections and cultured cells in this paper. On the tissue sections, we analyze telomere length with telomere intensity to centromere intensity ratio (TCR), centromere as an inner control. In the cultured cells, we analyze telomere lengths on each chromosome with karyotyping. Those Q-FISH methods by PNA probe are an accurate and reliable tool for research on telomere lengths in various conditions in biology. 展开更多
关键词 TELOMERE TELOMERE length Q-FISH Tissue section CHROMOSOME
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Accurate calculation of the elastic scattering properties of ^7Li atoms at ultralow temperatures 被引量:2
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作者 孙金锋 张计才 王杰敏 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第3期531-535,共5页
The elastic scattering properties for collisions between two ^7Li atoms are investigated in the cold and ultracold regimes separately. Based on recent theoretical and experimental results, we present the improved hybr... The elastic scattering properties for collisions between two ^7Li atoms are investigated in the cold and ultracold regimes separately. Based on recent theoretical and experimental results, we present the improved hybrid potentials for the singlet X^1 ∑g^+ and triplet a^3 ∑u^+ ground states of the Li2, Our calculated values for the scattering lengths α and the effective ranges re are compared with previous ones, and found them to be in good agreement. The scattering lengths are 34.6α0 for the singlet state and -27.6α0 for the triplet state. Shape resonances occur in the collisions at low energies. We also calculate the total cross sections and the energy positions of shape resonances for both X^1 ∑g^+ and a^3 ∑u^+ states. 展开更多
关键词 scattering length elastic cross section shape resonance
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On stability of elastic domain during isothermal solid-solid phase transformationin a tube configuration 被引量:1
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作者 Liang Dong Qing-Ping Sun 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第3期683-694,共12页
Under isothermal quasi-static stretching the phase transition of a superelastic NiTi tube involves the formation (during loading) and vanishing (in unloading) of a high strain (martensite) domain. The two events... Under isothermal quasi-static stretching the phase transition of a superelastic NiTi tube involves the formation (during loading) and vanishing (in unloading) of a high strain (martensite) domain. The two events are accompanied by a rapid stress drop/rise due to the formation/vanishing of do- main fronts. From a thermodynamic point of view, both are instability phenomena that occur once the system reaches its critical state. This paper investigates the stability of a shrink- ing cylindrical domain in a tube configuration during unload- ing. The energetics and thermodynamic driving force of the cylindrical domain are quantified by using an elastic inclu- sion model. It is demonstrated that the two domain fronts ex- hibit strong interaction when they come close to each other, which brings a peak in the total energy and a sign change in the thermodynamic driving force. It is proved that such domain front interaction plays an important role in control- ling the stability of the domain and in the occurrence of stress jumps during domain vanishing. It is also shown that the pro- cess is governed by two nondimensional length scales (the normalized tube length and normalized wall-thickness) and that the length scale dependence of the critical domain length and stress jump for the domain vanishing can be quantified by the elastic inclusion model. 展开更多
关键词 cylindrical elastic domain Stability of domain Domain front Critical domain length Stress jump ~ ther-modynamic driving force
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Calculation of the elastic scattering properties for cold and ultracold 39K atoms in a triplet state
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作者 胡秋波 王晓飞 +1 位作者 孙金锋 朱遵略 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第8期2367-2370,共4页
The elastic scattering properties for collisions between cold and ultracold 39K atoms in a triplet state are investigated. Based on the recent theoretical and experimental results, the improved hybrid potential is pre... The elastic scattering properties for collisions between cold and ultracold 39K atoms in a triplet state are investigated. Based on the recent theoretical and experimental results, the improved hybrid potential is presented for a triplet α3∑u^+ ground state of K2. Our calculated value of the s-wave scattering length a by using the Numerov method for the triplet state is 79.578α0 and found to be in good agreement with the previous ones. The numbers of bound states are supported by the molecular potential. Pronounced shape resonances appear for the l = 3 partial waves for the α3∑u^+ state. Furthermore, the s-wave scattering cross section, the total cross section and energy positions of shape resonances for the α3∑u^+ state are calculated. 展开更多
关键词 scattering length effective range elastic cross section shape resonance
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Calculation of the elastic collision properties of Na and Li atoms at ultracold temperature
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作者 张计才 张莹 +1 位作者 杜丙阁 孙金锋 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第4期1486-1490,共5页
This paper firstly reports a theoretical study of elastic scattering properties in a mixture of 23Na and 7Li atoms at cold and ultracold temperatures in detail. Based on the new constructed accurate singlet X1∑g+ an... This paper firstly reports a theoretical study of elastic scattering properties in a mixture of 23Na and 7Li atoms at cold and ultracold temperatures in detail. Based on the new constructed accurate singlet X1∑g+ and the triplet a3∑u+ states interatomic potentials for 23Na7Li mixture, it calculates the scattering lengths and the effective ranges by three computational methods, and obtains good agreements. Using the mass scaling method, it also calculates 23Na6Li scattering lengths and s-wave and total elastic cross sections, whose rich resonance structures were found and interpreted in terms of quasibound diatomic levels trapped behind a centrifugal barrier. 展开更多
关键词 scattering length elastic cross section variable phase method
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Dynamic behavior of single-layer latticed cylindrical shells subjected to seismic loading 被引量:4
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作者 沈世钊 邢佶慧 范峰 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2003年第2期269-279,共11页
The single-layer latticed cylindrical shell is one of the most widely adopted space-fl'amed structures.In this paper,free vibration properties and dynamic response to horizontal and vertical seismic waves of singl... The single-layer latticed cylindrical shell is one of the most widely adopted space-fl'amed structures.In this paper,free vibration properties and dynamic response to horizontal and vertical seismic waves of single-layer latticed cylindrical shells are analyzed by the finite element method using ANSYS software.In the numerical study,where hundreds of cases were analyzed,the parameters considered included rise-span ratio,length-span ratio,surface load and member section size.Moreover,to better define the actual behavior of single-layer latticed shells,the study is focused on the dynamic stress response to both axial forces and bending moments.Based on the numerical results,the effects of the parameters considered on the stresses are discussed and a modified seismic force coefficient method is suggested.In addition,some advice based on these research results is presented to help in the future design of such structures. 展开更多
关键词 single-layer latticed cylindrical shell dynamic behaviors seismic force coefficient method rise-span ratio length-span ratio surface load intensity member section size
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Size-dependent surface tension of a cylindrical nanobubble in liquid Ar 被引量:1
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作者 闫红 朱如曾 魏久安 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第8期146-151,共6页
In view of the continued disputes on the fundamental question of whether the surface tension of a vapour bubble in liquid argon increases, or decreases, or remains unchanged with the increase of curvature radius, a cy... In view of the continued disputes on the fundamental question of whether the surface tension of a vapour bubble in liquid argon increases, or decreases, or remains unchanged with the increase of curvature radius, a cylindrical vapour bubble of argon is studied by molecular dynamics simulation in this paper instead of spherical vapour bubble so as to reduce the statistical error. So far, the surface tension of the cylindrical vapour bubble has not been studied by molecular dynamics simulation in the literature. Our results show that the surface tension decreases with radius increasing. By fitting the Tolman equation with our data, the Tolman length σ = -0.6225 sigma is given under cut-off radius 2.5σ, where σ = 0.3405 nm is the diameter of an argon atom. The Tolman length of Ar being negative is affirmed and the Tolman length of Ar being approximately zero given in the literature is negated, and it is pointed out that this error is attributed to the application of the inapplicable empirical equation of state and the neglect of the difference between surface tension and an equimolar surface. 展开更多
关键词 cylindrical nanobubble surface tension Tolman length molecular dynamics simulation
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Optical Path Length,Temperature,and Wavelength Effects Simulation on Ozone Gas Absorption Cross Sections towards Green Communications
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作者 Michael David mohd haniff ibrahim +3 位作者 Sevia Mahdaliza Idrus Nor Hafizah Ngajikin Asrul Izam Azmi Tay Ching En Marcus 《Journal of Electronic Science and Technology》 CAS CSCD 2016年第3期199-204,共6页
Ozone is a green house gas. Ozone absorption cross sections have been reported with discrepancies and inconsistencies. In this paper, simultaneous effects of the optical path length and temperature variations on ozone... Ozone is a green house gas. Ozone absorption cross sections have been reported with discrepancies and inconsistencies. In this paper, simultaneous effects of the optical path length and temperature variations on ozone gas absorption cross sections are investigated at different wavelengths. HITRAN 2012, the latest available line list on spectralcalc.com simulator, is used in this study to simulate ozone gas absorption cross sections in relation to the simultaneous effects of the optical path length and temperature at the wavelengths of 603 nm and 575 nm. Results obtained for gas cells with the optical path length from 10 cm to 120 cm show that the decrease in temperatures from 313 K to 103 K results in the increase in ozone gas absorption cross sections. At wavelengths of 603 nm and 575 nm, the percentage increase of ozone gas absorption cross sections is 1.22% and 0.71%, respectively. Results obtained in this study show that in the visible spectrum, at constant pressure, ozone gas absorption cross sections are dependent on the temperature and wavelength but do not depend on the optical path length. Analysis in this work addresses discrepancies in ozone gas absorption cross sections in relation to the temperature in the visible spectrum; thus, the results can be applied to get optimal configuration of high accuracy ozone gas sensors. 展开更多
关键词 Index Terms--Absorption cross sections length OZONE PRESSURE TRANSMITTANCE visible spectrum.
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Post-Buckling Behavior of Laminated Composite Cylindrical Shells Subjected to Axial, Bending and Torsion Loads 被引量:1
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作者 Yengula Venkata Narayana Jagadish Babu Gunda +1 位作者 Ravinder Reddy Pinninti Markandeya Ravvala 《World Journal of Engineering and Technology》 2015年第4期185-194,共10页
In present work, post-buckling behavior of imperfect (of eigen form) laminated composite cylindrical shells with different L/D and R/t ratios subjected to axial, bending and torsion loads has been investigated by usin... In present work, post-buckling behavior of imperfect (of eigen form) laminated composite cylindrical shells with different L/D and R/t ratios subjected to axial, bending and torsion loads has been investigated by using an equilibrium path approach in the finite element analysis. The Newton-Raphson approach as well as the arc-length approach is used to ensure the correctness of the equilibrium paths up to the limit point load. Post-buckling behavior of imperfect cylindrical shells with different L/D and R/t ratios of interest is obtained and the theoretical knock-down factors are reported for the considered cylindrical shells. 展开更多
关键词 POST-BUCKLING cylindrical Shells Eigen IMPERFECTION Shapes AXIAL Compressive LOAD BENDING LOAD Torsion LOAD Arc-length Method KNOCK-DOWN Factor
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Time Course of Postoperative Complications in Low-Risk Women after Planned Cesarean Section
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作者 Anne Raabjerg Kruse Linn Håkonsen Arendt +5 位作者 Christian Erikstrup Ulrik Schiøler Kesmodel Finn Friis Lauszus Niels Uldbjerg Iben Sundtoft Axel Forman 《Open Journal of Obstetrics and Gynecology》 2022年第5期394-407,共14页
Objectives: Length of hospital stay after cesarean section is today much shorter than previously, and a stay of only 1 day is used in many departments. However, complications requiring immediate treatment must be diag... Objectives: Length of hospital stay after cesarean section is today much shorter than previously, and a stay of only 1 day is used in many departments. However, complications requiring immediate treatment must be diagnosed before leaving hospital. We assessed the time interval from planned cesarean section to diagnosis of major complications in low-risk women to estimate a safe time of discharge. Methods: We performed a retrospective observational study among 5633 women undergoing planned cesarean section from 2001-2017 at Aarhus University Hospital, Denmark. The inclusion criterion was postoperative complication graded as Clavien-Dindo ≥ II. Exclusion criteria were preoperative comorbidity or problems during surgery indicative of need for prolonged stay. Time from cesarean section to suspicion of a postoperative complication was the primary endpoint. Results: The study population consisted of 116 women with unexpected postoperative complications, 47 classified as Clavien-Dindo II and 69 as Clavien-Dindo III-IV. In 63 of the 116, the diagnoses were suspected within 24 hours (Clavien-Dindo II: 25, Clavien-Dindo III-IV: 38). These included all cases of relaparotomy and uterine atony with immediate need of medical treatment. Acute colonic pseudo-obstruction was diagnosed within 2 days, while other complications were suspected and treated 2 to 10 days postoperatively. Conclusions: Among low-risk women with a postoperative complication, all cases requiring relaparotomy and medically treated uterine atony were suspected within 24 hours after surgery. Discharge 24 hours after planned cesarean section seems safe in low-risk patients. 展开更多
关键词 Cesarean section Postoperative Complications Postoperative Hemorrhage Early Discharge length of Hospital Stay
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Steric Effects in the Cl+CHD3(v1=1) Reaction
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作者 Fengyan Wang Kopin Liu 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2013年第6期705-709,I0004,共6页
最近的研究揭示了完整的 3dimentional 反应 C1+CHD3 (v1=1 ) 的反应散布图画当 Cl 原子从对拉长的 CH 各自的各种各样的方向攻击 CHD3,结合。报导 polarizationdependent 微分生气的节提供对反应的试剂排列的影响的最详细的描述。传... 最近的研究揭示了完整的 3dimentional 反应 C1+CHD3 (v1=1 ) 的反应散布图画当 Cl 原子从对拉长的 CH 各自的各种各样的方向攻击 CHD3,结合。报导 polarizationdependent 微分生气的节提供对反应的试剂排列的影响的最详细的描述。传送对一般化学家更可存取的 stereospecific 信息,我们这里出现由合适的对称考虑,怎么从大小检索相对积分和二很普通的碰撞几何学的微分生气的节:在端点对 sideon 攻击。结果,虽然 coarsegrained,提供不仅关于化学反应增强我们的直觉,而且打开更多的灯在上的一幅呼吁的图画常规(unpolarized ) 属性。 展开更多
关键词 反应散射 立体效果 CL 微分截面 化学反应性 反应路线 偏振相关 几何形状
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北京某三级甲等医院营养支持现状横断面调研分析
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作者 商永光 夏天一 +3 位作者 蒋心瑞 赖宗强 孔旭东 张镭 《中国医院用药评价与分析》 2024年第1期104-108,共5页
目的:对中日友好医院(以下简称“该院”)营养支持现状进行调研,评价营养支持的合理性,探讨营养支持对住院费用及住院时间的影响。方法:开展横断面研究,纳入2023年3月1—15日入住该院并接受营养支持的成人患者,收集患者基础信息,对患者... 目的:对中日友好医院(以下简称“该院”)营养支持现状进行调研,评价营养支持的合理性,探讨营养支持对住院费用及住院时间的影响。方法:开展横断面研究,纳入2023年3月1—15日入住该院并接受营养支持的成人患者,收集患者基础信息,对患者进行营养风险筛查与评估,评价营养支持指征的合理性;观察能量及蛋白摄入情况对患者血清白蛋白、住院时间及住院费用的影响。结果:共纳入602例患者,经筛查存在营养风险的患者所占比例为58.0%(349/602);与无营养风险的患者比较,有营养风险的患者住院时间长(P=0.008)、费用高(P=0.001),差异均有统计学意义;肠外营养应用比例为68.6%(413/602)。能量及蛋白摄入达60%目标需求的有290例(占48.2%),与能量及蛋白摄入不足60%目标需求的患者比较,达标患者营养支持后血清前白蛋白水平升高,差异有统计学意义(P=0.000)。存在营养风险的围手术期患者,充足的营养支持显著缩短其住院时间(P=0.041)。无营养风险的围手术期患者,营养支持显著增加其住院费用(P=0.006)。无营养风险的消化系统疾病患者,营养支持显著延长其住院时间(P=0.000),增加其住院费用(P=0.005)。结论:规范的营养支持与患者血清前白蛋白水平改善相关,可在不增加住院费用的前提下缩短围手术期患者住院时间。该院现阶段临床营养支持存在营养不良诊断不完善及方案不合理等问题,需要进一步完善营养支持路径,促进临床营养支持规范化。 展开更多
关键词 营养支持 围手术期 住院时间 营养风险 横断面研究
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基于可拓理论的隧道洞口段动力响应规律研究
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作者 周佳媚 李瑞涵 +2 位作者 黄柯 崔凯琪 岳飞翔 《地下空间与工程学报》 CSCD 北大核心 2024年第2期625-635,共11页
隧道洞口段存在偏压浅埋、围岩破碎等情况,为探究隧道洞口段在地震作用下的动力响应规律并给出安全性定量评估指标,以雅万高铁6号隧道为依托建立数值模型,分别输入雅万人工合成波、EI波、KB波以及WL波4个地震波,基于可拓理论,建立可拓... 隧道洞口段存在偏压浅埋、围岩破碎等情况,为探究隧道洞口段在地震作用下的动力响应规律并给出安全性定量评估指标,以雅万高铁6号隧道为依托建立数值模型,分别输入雅万人工合成波、EI波、KB波以及WL波4个地震波,基于可拓理论,建立可拓物元模型,对采用数值模拟方法得出的隧道洞口段在最不利地震波作用下的弯矩、轴力、相对位移、加速度4个安全评估指标结果创建分区,以综合定量指标对雅万高铁6号隧道洞口段进行安全性评估,并提出了抗震设防长度。同时,分析了在不同地震波作用下的雅万高铁6号隧道洞口段的动力响应规律。结果表明:(1)在雅万人工波作用下,隧道各评估点动力响应程度约为其余3种天然波作用下动力响应程度的1.2倍;(2)各地震波计算所得4个评估指标沿纵向方向变化规律基本相同,轴力及弯矩峰值均出现在拱肩拱脚位置,相对位移峰值均发生在洞口处仰拱至拱顶测线,评估指标峰值发生时刻略微滞后于地震波峰值加速度对应时刻;(3)在雅万人工合成波作用下,雅万高铁六号隧道洞口段抗震设防长度为45~55 m,为隧道洞径的3.5~4倍。研究成果可为通过综合定量指标对隧道洞口段进行抗震安全性评估提供参考。 展开更多
关键词 高速铁路 隧道洞口段 数值模拟 抗震设防长度 可拓理论
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深海无人系统大长径比环肋圆柱壳结构设计与试验研究
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作者 陈沙古 高原 +3 位作者 吴智睿 郁伟 周成 刘成 《海洋工程》 CSCD 北大核心 2024年第1期115-123,共9页
环肋圆柱壳是深海无人系统广泛采用的一种耐压结构形式,保障其结构安全是系统研制过程中非常重要的一环。针对环肋圆柱壳的结构特征推导了组合结构重量关系式和结构参数简化估算方法,并以一种超长型深海无人系统耐压结构为例,围绕大长... 环肋圆柱壳是深海无人系统广泛采用的一种耐压结构形式,保障其结构安全是系统研制过程中非常重要的一环。针对环肋圆柱壳的结构特征推导了组合结构重量关系式和结构参数简化估算方法,并以一种超长型深海无人系统耐压结构为例,围绕大长径比环肋圆柱壳的结构形式、设计计算、仿真分析、模型验证等开展研究。研究表明提出的大长径比环肋圆柱壳结构设计参数简化估算方法具有较好的适应性。相关计算和分析结果可以为该型深海无人系统结构设计提供技术支撑,也可以为其他类似耐压结构设计提供参考。 展开更多
关键词 环肋圆柱壳 大长径比 结构设计 耐压结构 深海无人系统
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平面截圆柱面截痕形状问题的探讨
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作者 杨传富 《高等数学研究》 2024年第2期53-54,共2页
本文探讨平面截圆柱面的截痕形状,旨在加强直观上对该问题的认知及运用.
关键词 圆柱面 截痕
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柱面坐标计算三重积分的截面法
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作者 张立国 《高等数学研究》 2024年第2期66-68,共3页
文章尝试利用柱面坐标的截面法计算三重积分,为学生理解和掌握三重积分的计算提供一点经验与帮助.
关键词 三重积分 柱面坐标系 截面法
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