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New Resolution to Coupling Loss Factor of Beam Plate Structure
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作者 刘景泉 姚德源 《Journal of Beijing Institute of Technology》 EI CAS 2000年第3期267-272,共6页
The transmission of transverse vibrational energy of a vertically rigid beam plate coupled structure is analyzed to get the theoretical results of coupling loss factor(CLF), a very important parameter in statistical ... The transmission of transverse vibrational energy of a vertically rigid beam plate coupled structure is analyzed to get the theoretical results of coupling loss factor(CLF), a very important parameter in statistical energy analysis(SEA). The modal analysis method is used to discuss the vibration energy of the typical model, as well as the power flow between the two subsystems. Furthermore, the resolution to the coupling loss factor is also derived and compared with the measured values. The analytical results of the coupling loss factor agree with the measured ones fully, this new resolution is significant for the application of SEA. 展开更多
关键词 statistical energy analysis coupling loss factor modal analysis method
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Loss Factors and their Effect on Resonance Peaks in Mechanical Systems 被引量:1
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作者 Roman Vinokur 《Sound & Vibration》 EI 2023年第1期1-13,共13页
The loss factors and their effects on the magnitude and frequency of resonance peaks in various mechanical sys-tems are reviewed for acoustic,vibration,and vibration fatigue applications.The main trends and relationsh... The loss factors and their effects on the magnitude and frequency of resonance peaks in various mechanical sys-tems are reviewed for acoustic,vibration,and vibration fatigue applications.The main trends and relationships were obtained for linear mechanical models with hysteresis damping.The well-known features(complex module of elasticity,total loss factor,etc.)are clarified for practical engineers and students,and new results are presented(in particular,for 2-DOF in-series models with hysteresis friction).The results are of both educational and prac-tical interest and may be applied for NVH analysis and testing,mechanical and aeromechanical design,and noise and vibration control in buildings. 展开更多
关键词 Mechanical loss factor resonance peak ACOUSTICS VIBRATION structural failure noise NVH engineering systems
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Simulation of higher order modes and loss factor of a new type of 500-MHz single cell superconducting cavity at SSRF 被引量:3
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作者 YU Haibo LIU Jianfei +5 位作者 HOU Hongtao LU Changwang WEI Yelong MA Zhenyu FENG Ziqiang MAO Dongqing 《Nuclear Science and Techniques》 SCIE CAS CSCD 2011年第5期257-260,共4页
In this paper,higher order modes(HOMs) and loss factor of a new type of 500-MHz superconducting cavity is studied,by simulating its broadband HOMs damping at different positions of the ferrite HOM-absorber and differe... In this paper,higher order modes(HOMs) and loss factor of a new type of 500-MHz superconducting cavity is studied,by simulating its broadband HOMs damping at different positions of the ferrite HOM-absorber and different lengths of the ferrite.The results show that the impedance and Q value of the HOMs in transverse and longitudinal modes could be greatly reduced.The HOM longitudinal impedance could be damped to meet the requirement of SSRF beam instability threshold.The calculated loss factor of the new SC cavity was compared with cavities at SSRF.It was estimated that the HOM absorber could absorb a total power of 3.16 kW at 4-mm beam bunch length. 展开更多
关键词 损耗因子 高阶模 超导腔 光源 上海 模拟 单细胞 纵向阻抗
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On-line Monitoring of Insulation Dielectric Loss Factor Based on Balance Principle
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作者 Tianxiang CHEN Zhenhua SHAO +1 位作者 Shaozhen QIN Hong TIAN 《电力系统自动化》 EI CSCD 北大核心 2013年第21期180-183,共4页
关键词 介质损耗因数 平衡原则 在线监测 绝缘 相位误差 高精确度 电流传感器 位移传感器
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Identification of Modal Loss Factor of a Sandwich Composite Structure with Polyethylene Terephthalate Core in the Aspect of Core Properties Determination
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作者 Krzysztof Marynowski Katarzyna Grochowska 《Materials Sciences and Applications》 2015年第6期473-488,共16页
Comparison of the loss factor determination methods of the sandwich composite structure with polyethylene terephthalate core in the aspect of core material rheological parameters identification was the purpose of the ... Comparison of the loss factor determination methods of the sandwich composite structure with polyethylene terephthalate core in the aspect of core material rheological parameters identification was the purpose of the study. Three frequency bandwidths n dB: 1 dB, 2 dB, 3 dB methods, the resonant amplitude method and the fit method of the response of the one degree of freedom model system are taken into considerations. Identification procedure, according to ASTM E756-2005 [1] based on experimental studies of the forced vibrations of the composite structure was presented in the paper. To determine the function of the complex shear modulus of the core material, the Nelder-Mead method is applied. Shear modulus and loss factor identification results were presented on the plots in the frequency domain. The results in a quantitative manner set the applied methods and their practical utility in order. 展开更多
关键词 Composite Material RHEOLOGICAL Fractional Model VISCOELASTICITY loss factor Shear MODULUS
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Analysis of the causes of formation of negative loss factors 被引量:4
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作者 SUN Zhaohui SUN Jincai WANG Chong and SHENG Meiping(Institute of Acoustic Engineering, Northwestern Polytechnical University Xi’an, 710072) 《Chinese Journal of Acoustics》 1996年第3期239-246,共8页
Based on classical energy balance equations for two coupled systems in Statistical Energy Analyis (SEA), the possibility of causing negative loss factors in measuring SEA parameters by using the equations is analyzed.... Based on classical energy balance equations for two coupled systems in Statistical Energy Analyis (SEA), the possibility of causing negative loss factors in measuring SEA parameters by using the equations is analyzed. The physical causes of formation of negative loss factors are theoretically invstigated by vibration analysis of the two non-conservatively coupled oscillator sets. Mom the analytical results, it is shown that the necessary condition of foedng negatbo loss factors is that the coupling of the coupled systems is non-conservative and strong and the suffiient condition is that the excitation frequency of the external force is not equal to the natural frequencies of the two oscillators at the sam tAne or the parameters of the two oscillators are much different. The absolute values of the negative loss factors increase with the increase of the coupling pararneters. 展开更多
关键词 SEA Negative loss factor SEA parameters
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The coupling loss factors for non-conservatively coupled structures 被引量:3
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作者 SHENG Meiping(Institute of Acoustic Enmneering, Northwestern Polytechnzcal Uniuersity Xi’an 710072)Wang Minqing(Institute of Vibration and Noise Control, Xi ’an Jiaotong University Xi’an’ 710049)SUN Jincai(Institute of Aconstic Engineering, Northwestern P 《Chinese Journal of Acoustics》 1998年第4期299-306,共8页
The method to calculate the coupling loss factors for non-conservatively coupled structures by using the mobilities of substructures is studied. By using the form of the energy balance equations of conservatively coup... The method to calculate the coupling loss factors for non-conservatively coupled structures by using the mobilities of substructures is studied. By using the form of the energy balance equations of conservatively coupled systems, the relationship between the coupling loss factors and the energy ratios in non-conservatively coupled systems is derived. The method to calculate the energy ratios by using the mobilities of substructures is introduced, and experiment verification is carried out. The test data agree well with the predicted results. 展开更多
关键词 ACTA The coupling loss factors for non-conservatively coupled structures
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Power Transformer No-Load Loss Prediction with FEM Modeling and Building Factor Optimization 被引量:2
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作者 Ehsan Hajipour Pooya Rezaei +1 位作者 Mehdi Vakilian Mohsen Ghafouri 《Journal of Electromagnetic Analysis and Applications》 2011年第10期430-438,共9页
Estimation of power transformer no-load loss is a critical issue in the design of distribution transformers. Any deviation in estimation of the core losses during the design stage can lead to a financial penalty for t... Estimation of power transformer no-load loss is a critical issue in the design of distribution transformers. Any deviation in estimation of the core losses during the design stage can lead to a financial penalty for the transformer manufacturer. In this paper an effective and novel method is proposed to determine all components of the iron core losses applying a combination of the empirical and numerical techniques. In this method at the first stage all computable components of the core losses are calculated, using Finite Element Method (FEM) modeling and analysis of the transformer iron core. This method takes into account magnetic sheets anisotropy, joint losses and stacking holes. Next, a Quadratic Programming (QP) optimization technique is employed to estimate the incomputable components of the core losses. This method provides a chance for improvement of the core loss estimation over the time when more measured data become available. The optimization process handles the singular deviations caused by different manufacturing machineries and labor during the transformer manufacturing and overhaul process. Therefore, application of this method enables different companies to obtain different results for the same designs and materials employed, using their historical data. Effectiveness of this method is verified by inspection of 54 full size distribution transformer measurement data. 展开更多
关键词 BUILDING factor CORE lossES FINITE ELEMENT Method Power Transformer
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Activation of hypoxia-inducible factor 1 attenuates periapical inflammation and bone loss 被引量:26
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作者 Kimito Hirai Hisako Furusho +1 位作者 Kiichi Hirota Hajime Sasaki 《International Journal of Oral Science》 SCIE CAS CSCD 2018年第2期92-101,共10页
Hypoxia(low oxygen level) is an important feature during infections and affects the host defence mechanisms. The host has evolved specific responses to address hypoxia, which are strongly dependent on the activation... Hypoxia(low oxygen level) is an important feature during infections and affects the host defence mechanisms. The host has evolved specific responses to address hypoxia, which are strongly dependent on the activation of hypoxia-inducible factor 1(HIF-1).Hypoxia interferes degradation of HIF-1 alpha subunit(HIF-1α), leading to stabilisation of HIF-1α, heterodimerization with HIF-1 beta subunit(HIF-1β) and subsequent activation of HIF-1 pathway. Apical periodontitis(periapical lesion) is a consequence of endodontic infection and ultimately results in destruction of tooth-supporting tissue, including alveolar bone. Thus far, the role of HIF-1 in periapical lesions has not been systematically examined. In the present study, we determined the role of HIF-1 in a wellcharacterised mouse periapical lesion model using two HIF-1α-activating strategies, dimethyloxalylglycine(DMOG) and adenovirusinduced constitutively active HIF-1α(CA-HIF1 A). Both DMOG and CA-HIF1 A attenuated periapical inflammation and tissue destruction. The attenuation in vivo was associated with downregulation of nuclear factor-κappa B(NF-κB) and osteoclastic gene expressions. These two agents also suppressed NF-κB activation and subsequent production of proinflammatory cytokines by macrophages. Furthermore, activation of HIF-1α by DMOG specifically suppressed lipopolysaccharide-stimulated macrophage differentiation into M1 cells, increasing the ratio of M2 macrophages against M1 cells. Taken together, our data indicated that activation of HIF-1 plays a protective role in the development of apical periodontitis via downregulation of NF-κB, proinflammatory cytokines, M1 macrophages and osteoclastogenesis. 展开更多
关键词 CA Activation hypoxia-inducible factor attenuates periapical inflammation bone loss HIF
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Factor value determination and applicability evaluation of universal soil loss equation in granite gneiss region
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作者 Wen-hai ZHANG Xing-nan ZHANG Zhi-dong GAO 《Water Science and Engineering》 EI CAS 2009年第2期87-97,共11页
Six types of runoff plots were set up and an experimental study was carried out to examine natural rate of soil and water loss in the granite gneiss region of northern Jiangsu Province in China. Through correlation an... Six types of runoff plots were set up and an experimental study was carried out to examine natural rate of soil and water loss in the granite gneiss region of northern Jiangsu Province in China. Through correlation analysis of runoff and soil loss during 364 rainfall events, a simplified and convenient mathematical formula suitable for calculating the rainfall erosivity factor (R) for the local region was established. Other factors of the universal soil loss equation (USLE model) were also determined. Relative error analysis of the soil loss of various plots calculated by the USLE model on the basis of the observed values showed that the relative error ranged from -3.5% to 9.9% and the confidence level was more than 90%. In addition, the relative error was 5.64% for the terraced field and 12.36% for the sloping field in the practical application. Thus, the confidence level was above 87.64%. These results provide a scientific basis for forecasting and monitoring soil and water loss, for comprehensive management of small watersheds, and for soil and water conservation planning in the region. 展开更多
关键词 granite gneiss region soil erosion universal soil loss equation factor value applicability evaluation
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Analysis on the Influence Factors of Capacitor Voltage Transformer Dielectric Loss Measurement
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作者 Yongdong Li Qing-da Meng +3 位作者 Po Yang Zheyuan Zhao Wei Zhang Zhuo Pan 《Energy and Power Engineering》 2013年第4期1240-1242,共3页
Capacitor voltage transformer (CVT), which is with simple structure, convenient maintenance, functional diversity and high impact pressure strength, is widely used. And its capacitance and dielectric loss Angle measur... Capacitor voltage transformer (CVT), which is with simple structure, convenient maintenance, functional diversity and high impact pressure strength, is widely used. And its capacitance and dielectric loss Angle measurement is an important test on testing the insulation of the equipment. This paper is mainly to introduce and discuss one of the CVT test methods——the “self excitation method”, combined with the actual situation encountered in the work, sums up and expounds the maintenance of CVT and preventive test of influence factors. 展开更多
关键词 Capacitive VOLTAGE TRANSFORMER DIELECTRIC loss the Influencing factorS
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Effects of Orlistat - induced Weight Loss on Cardiovascular Risk Factors in Obese Chinese Subjects
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作者 徐明彤 吴木潮 +3 位作者 黎锋 周淑娴 程桦 傅祖植 《South China Journal of Cardiology》 CAS 2003年第1期1-4,共4页
Objectives To observe the influence of weight loss induced by orlistat on several cardiovascular diseases risk factors in obese Chinese subjects. Methods Sixty obese Chinese patients participated in a 24 week clinical... Objectives To observe the influence of weight loss induced by orlistat on several cardiovascular diseases risk factors in obese Chinese subjects. Methods Sixty obese Chinese patients participated in a 24 week clinical trial. Participants were prescribed a slightly hypocaloric diet and exercise, then they were randomly assigned double -blind treatment with either orlistat 120 mg three times a day or placebo. Their body weight, blood pressure, fasting glucose, insulin, HbA1c, and serum lipid profile were performed before and after the weight loss intervention. Results After 24 weeks, orlistat -treated group lost more of their body weight than placebo group (6. 66 ± 0. 52 kg, 8. 44±4.08% and 1. 98 ± 0. 44 kg, 2. 44±1. 74 % , respectively, P < 0. 05) . Moreover, after treatment, orlistat - treated patients showed significant decreases in serum levels of total cholesterol, low density lipoprotein - cholesterol and high density lipoprotein - cholesterol ( P < 0.01), but in placebo group we found no change. Both systolic blood pressure and diastolic blood pressure fell significantly in orlistat - treated group. Fasting glucose and HOMA - IR in orlistat - treated group was distinctly reduced if compared with placebo group. Conclusions Weight loss resulting from orlistat treatment and slightly hypocaloric diet has produced favorable effects on several cardiovascular risk factors in obese Chinese subjects. 展开更多
关键词 Orlistat Weight loss Cardiovascular risk factors
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Investigation of Pile Construction and Productivity Loss: An Analysis of Macro Impact Factor
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作者 Minhaz Ahmed Wang Xu 《World Journal of Engineering and Technology》 2023年第4期932-964,共33页
Pile foundations are challenging to build due to subsurface obstacles, contractor ignorance, and difficulties with site planning. Given the unpredictable environment of the construction site, productivity losses durin... Pile foundations are challenging to build due to subsurface obstacles, contractor ignorance, and difficulties with site planning. Given the unpredictable environment of the construction site, productivity losses during pile work are to be thought possible. Prior to finishing a site pre-investigation, a foundation’s area is usually sampled for statistical reasons. There are studies on pile construction outside of Bangladesh that are supported by relevant empirical data in the literature. Since Bangladesh, which is regarded as a third-world country, is ignored in this regard, the literature currently available about pile building and the associated productivity loss is unable to provide adequate information or appropriate empirical data. Due to this pile-building sector in Bangladesh has been experiencing a decline in production for quite some time now. Before attempting to increase productivity in pile construction, it is essential to investigate the potential losses and the variables that might have an influence. This study aims to accomplish the following objectives: 1) identify the primary factors that have an impact on pile construction;2) develop an SVR model that accurately predicts productivity loss;and 3) figure out the projected loss by basing it on the historical scenario that is the most comparable to the current one. A Support Vector Regression (SVR) model was developed after a study of the relevant literature. This model enabled the collection of 110 pile building projects from five significant locations in Bangladesh. The model was constructed using a list of eight inputs in addition to a list of five macro elements (labor, management, environment, material, and equipment) (soil condition, pile type, pile material, project size, project location, pile depth, pile quantity, and equipment quantity). Using 10-way cross validation, the SVR achieves an accuracy of 87.2% in its predictions. On the basis of what has occurred in the past, we are able to estimate that there will be a loss of around 18.55 percent of the total output. A new perspective for engineers studying the delay factors with productivity loss is provided by the outcome of important tasks as it relates to loss in productivity and overall factors faced. In the building construction industry, effective management should place more emphasis on the correlation between productivity loss and the factors that cause it. Therefore, to represent the effect on productivity loss, real factors can be summed up as a decline in productivity loss. The findings of the study would urge specialists to concentrate on waste as a means of increasing overall production. 展开更多
关键词 Productivity loss Macro-Effect factor Pile Construction Regression Model SVR Model
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Sensitivity of Pion versus Parton-Jet Nuclear Modification Factors to the Path-Length Dependence of Jet-Energy Loss at RHIC and LHC
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作者 Barbara Betz Miklos Gyulassy 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第12期30-34,共5页
We compare the jet-path length and beam-energy dependence of the pion nuclear modification factor and a patton-jet nuclear modification factor at RHIC and LHC, and contrast the predictions based on a linear pQCD and a... We compare the jet-path length and beam-energy dependence of the pion nuclear modification factor and a patton-jet nuclear modification factor at RHIC and LHC, and contrast the predictions based on a linear pQCD and a highly non-linear hybrid AdS holographic model of jet-energy loss. It is found that both models require a reduction of the jet-medium coupling from RHIC to LHC to account for the measured pion nuclear modification factor. In the case of the parton-jet nuclear modification factor, however, which serves as a lower bound for the LO jet nuclear modification factor of reconstructed jets, the extracted data can be characterized without a reduced jet-medium coupling at LHC energies. It is concluded that when the reconstructed jets are sensitive to both quarks and gluons and thus provide more information than the pion nuclear modification factor, their information regarding the jet-medium coupling is limited due to the superposition with NLO and medium effects. Hence, a detailed description of the underlying physics requires both the leading hadron and the reconstructed jet nuclear modification factor. Unfortunately, the results for both the pion and the parton-jet nuclear modification factor are insensitive to the jet-path dependence of the models considered. 展开更多
关键词 LHC Sensitivity of Pion versus Parton-Jet Nuclear Modification factors to the Path-Length Dependence of Jet-Energy loss at RHIC and LHC
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Selective deletion of the soluble Colony-Stimulating Factor 1 isoform in vivo prevents estrogen-deficiency bone loss in mice
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作者 Gang-Qing Yao Nancy Troiano +1 位作者 Christine A Simpson Karl L Insogna 《Bone Research》 SCIE CAS CSCD 2017年第4期367-374,共8页
Neutralizing CSF1 in vivo completely prevents ovariectomy (OVX)-induced bone loss in mice. There are two isoforms of CSF1, soluble (sCSF1), and membrane-bound (mCSF1), but their individual biological functions a... Neutralizing CSF1 in vivo completely prevents ovariectomy (OVX)-induced bone loss in mice. There are two isoforms of CSF1, soluble (sCSF1), and membrane-bound (mCSF1), but their individual biological functions are unclear. It had been previously reported that mCSF1 knockout (K/O) and wild type (Wt) female mice experience the same degree of bone loss following OVX. In Wt mice the expression of sCSF1 was elevated fourfold in skeletal tissue following OVX while expression of mCSF1 was unchanged. To examine the role of sCSF1 in OVX-induced bone loss, mice were engineered in which sCSF1 was not expressed but expression of mCSF1 was unaffected (sCSF1 K/O). Isoform-specific reverse transcription PCR confirmed the absence of transcripts for sCSF1 in bone tissue isolated from these animals and no circulating CSF1 was detected by ELISA. Surprisingly, there were no significant differences in bone mineral density (BMD) between sCSF1 K/O mice and Wt controls as assessed by dual-energy X-ray absorptiometry and micro-CT. However, one month after OVX, femoral, spinal and total BMD had declined by 11.2%, 8.9%, and 8.7% respectively in OVX-Wt animals as compared to Sham-OVX. In contrast OVX sCSF1 K/O mice showed changes of +0.1%, - 2.4%, and +2.3% at the same 3 sites compared to Sham-OVX sCSF1 K/O mice. These data indicate important non-redundant functions for the two isoforms of CSF1 and suggest that sCSF1, but not mCSF1, plays a key role in estrogen-deficiency bone loss. 展开更多
关键词 CSF Selective deletion of the soluble Colony-Stimulating factor 1 isoform in vivo prevents estrogen-deficiency bone loss in mice
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Evaluation of C and P Factors in Universal Soil Loss Equation on Trapping Sediment: Case Study of Santubong River 被引量:3
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作者 Kelvin K. K. Kuok Darrien Y. S. Mah P. C. Chiu 《Journal of Water Resource and Protection》 2013年第12期1149-1154,共6页
Universal Soil Loss Equation (USLE) is the most comprehensive technique available to predict the long term average annual rate of erosion on a field slope. USLE was governed by five factors include soil erodibility fa... Universal Soil Loss Equation (USLE) is the most comprehensive technique available to predict the long term average annual rate of erosion on a field slope. USLE was governed by five factors include soil erodibility factor (K), rainfall and runoff erodibility index (R), crop/vegetation and management factor (C), support practice factor (P) and slope length-gradient factor (LS). In the past, K, R and LS factors are extensively studied. But the impacts of factors C and P to outfall Total Suspended Solid (TSS) and % reduction of TSS are not fully studied yet. Therefore, this study employs Buffer Zone Calculator as a tool to determine the sediment removal efficiency for different C and P factors. The selected study areas are Santubong River, Kuching, Sarawak. Results show that the outfall TSS is increasing with the increase of C values. The most effective and efficient land use for reducing TSS among 17 land uses investigated is found to be forest with undergrowth, followed by mixed dipt. forest, forest with no undergrowth, cultivated grass, logging 30, logging 10^6, wet rice, new shifting agriculture, oil palm, rubber, cocoa, coffee, tea and lastly settlement/cleared land. Besides, results also indicate that the % reduction of TSS is increasing with the decrease of P factor. The most effective support practice to reduce the outfall TSS is found to be terracing, followed by contour-strip cropping, contouring and lastly not implementing any soil conservation practice. 展开更多
关键词 Universal Soil loss Equation Crop/Vegetation and Management factor (C) Support Practice factor (P) OUTFALL TOTAL Suspended SOLID % Reduction of TOTAL Suspended SOLID
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新方法计算经椎间孔腰椎椎体间融合围术期隐性失血及风险因素
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作者 彭煜健 谢玉 +1 位作者 王前亮 蒋凤仙 《中国组织工程研究》 北大核心 2026年第21期5549-5555,共7页
背景:经椎间孔腰椎椎体间融合是治疗腰椎间盘突出、腰椎管狭窄和腰椎滑脱等腰椎退行性疾病主要的手术方式之一。隐性失血是指患者隐匿性丧失的血量,往往被人们忽视。目的:使用新方法评估经椎间孔腰椎椎体间融合围术期总失血量情况,基于... 背景:经椎间孔腰椎椎体间融合是治疗腰椎间盘突出、腰椎管狭窄和腰椎滑脱等腰椎退行性疾病主要的手术方式之一。隐性失血是指患者隐匿性丧失的血量,往往被人们忽视。目的:使用新方法评估经椎间孔腰椎椎体间融合围术期总失血量情况,基于新方法计算得出隐性失血量,并分析其危险因素。方法:回顾性分析2023年10月至2024年10月于苏州大学附属第二医院脊柱外科住院治疗的93例腰椎退行性疾病(腰椎管狭窄、腰椎间盘突出及腰椎滑脱等)患者的病历资料。收集患者一般资料如年龄、性别、身高、体质量、体质量指数以及是否合并有高血压、糖尿病;手术资料如手术节段数目、手术时间、美国麻醉师协会麻醉分级;实验室检查如凝血酶原时间、活化部分凝血活酶时间、国际标准化比率、血小板计数、纤维蛋白原、D-二聚体水平。采用Pearson或Spearman相关性分析探讨患者特征与术后隐性失血之间的相关性,以多元线性回归分析确定术后隐性失血的独立危险因素。结果与结论:①新方法计算出经椎间孔腰椎椎体间融合的平均隐性失血量为(284.24±352.76)mL,占总失血量的58.6%;而传统手术方法计算出平均隐性失血量为(165.77±339.89)mL,占总失血量的34.15%,两者之间差异有显著性意义(P<0.05);②单因素分析中,隐性失血量与节段数目(r=0.213,P=0.040)和手术时间(r=0.210,P=0.043)呈正相关,与血小板计数呈负相关(r=-0.324,P=0.018);③多元线性回归分析中,血小板计数减少是影响隐性失血的独立危险因素(P=0.016);④提示新方法对于隐性失血量的估计更准确,隐性失血为围术期总失血量的重要组成部分;节段数目增多、手术时间延长、血小板计数减少是经椎间孔腰椎椎体间融合隐性失血的危险因素,其中血小板计数减少是独立危险因素。 展开更多
关键词 隐性失血 新方法 经椎间孔腰椎椎体间融合术 危险因素 围术期失血
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Properties of Defect Modes in Periodic Lossy Multilayer with Negative-Index-Materials
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作者 Alireza Aghajamal Mahmood Barati 《Communications in Theoretical Physics》 SCIE CAS CSCD 2013年第7期80-86,共7页
Employing the characteristic matrix method, this study investigates transmission properties of onedimensional defective lossy photonic crystals composed of negative and positive refractive index layers with one lossle... Employing the characteristic matrix method, this study investigates transmission properties of onedimensional defective lossy photonic crystals composed of negative and positive refractive index layers with one lossless defect layer at the center of the crystal. The results of the study show that as the refractive index and thickness of the defect layer increase, the frequency of the defect mode decreases. In addition, the study shows that the frequency of the defect mode is sensitive to the incidence angle, polarization, and physical properties of the defect layer, but it is insensitive to the small lattice loss factor. The peak of the defect mode is very sensitive to the loss factor, incidence angle, polarization, refractive index, and thickness of the defect layer. This study also shows that the peak and the width of the defect mode are affected by the numbers of the lattice period and the loss factor. The results can lead to designing new types of narrow filter structures and other optical devices. 展开更多
关键词 one-dimensional photonic crystal defect mode loss factor negative index material
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敲低Linc00052表达对成骨细胞增殖、迁移和凋亡的影响
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作者 齐鲁 王俊杰 +1 位作者 邓钦高 王星 《中国组织工程研究》 北大核心 2026年第12期2949-2956,共8页
背景:Linc00052与多种疾病的发生和发展密切相关,包括癌症和炎症性疾病。研究发现,Linc00052靶向miR-145发挥人关节软骨细胞损伤的保护作用。目的:观察敲低Linc00052对成骨细胞增殖、迁移和凋亡的影响方法:(1)收集30例人根尖周炎骨组织... 背景:Linc00052与多种疾病的发生和发展密切相关,包括癌症和炎症性疾病。研究发现,Linc00052靶向miR-145发挥人关节软骨细胞损伤的保护作用。目的:观察敲低Linc00052对成骨细胞增殖、迁移和凋亡的影响方法:(1)收集30例人根尖周炎骨组织与30例人健康根尖周骨组织,RT-qPCR检测Linc00052、miR-145表达。(2)将第3代CP-H111成骨细胞分2组培养:实验组转染慢病毒敲低Linc00052表达,对照组转染空载慢病毒阴性对照,转染72 h后,RT-qPCR检测Linc00052、miR-145表达,Western blot检测肿瘤坏死因子α与转化生长因子β/SMAD2/SMAD3信号通路蛋白表达,CCK-8实验检测细胞增殖,划痕实验、Transwell小室实验检测细胞迁移,流式细胞术检测细胞凋亡。结果与结论:(1)根尖周炎根尖周骨组织中Linc00052表达高于健康根尖周骨组织(P<0.05),miR-145表达低于健康根尖周骨组织(P<0.05);(2)实验组细胞内Linc00052表达、细胞凋亡与肿瘤坏死因子α蛋白表达低于对照组(P<0.05),miR-145表达与转化生长因子β1、p-SMAD2、p-SMAD3蛋白表达高于对照组,细胞迁移能力强于对照组;(3)结果表明,敲低Linc00052可通过负调控miR-145表达降低肿瘤坏死因子α蛋白表达、激活转化生长因子β/SMAD2/SMAD3信号通路,促进成骨细胞的增殖、迁移并抑制细胞凋亡。 展开更多
关键词 Linc00052 成骨细胞 肿瘤坏死因子Α 转化生长因子β/SMAD2/SMAD3信号通路 根尖周炎骨缺损
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老年牙列缺损患者口腔健康素养调查及影响因素分析
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作者 闵玉娣 李英 +1 位作者 肖瑞 罗葳 《中华老年口腔医学杂志》 2026年第1期25-30,共6页
目的系统评估老年牙列缺损患者的口腔健康素养水平,同时深入探究影响因素,为制定精准化的口腔健康教育与干预措施提供依据。方法便利抽样法选取2024年1月至2025年6月于北京大学人民医院口腔科就诊的老年牙列缺损患者578例,采用一般资料... 目的系统评估老年牙列缺损患者的口腔健康素养水平,同时深入探究影响因素,为制定精准化的口腔健康教育与干预措施提供依据。方法便利抽样法选取2024年1月至2025年6月于北京大学人民医院口腔科就诊的老年牙列缺损患者578例,采用一般资料调查表收集患者的基本信息,并使用简约版口腔健康素养量表(health literacy dental scale,HeLD-14)评估其口腔健康素养水平,运用单因素分析对比不同特征老年牙列缺损患者的HeLD-14评分,并借助多因素线性回归模型识别其关键影响因素。结果578例老年牙列缺损患者HeLD-14总分为(44.15±10.80)分。单因素分析结果表明,不同医保类型、文化程度、年收入、吸烟及牙列缺损时间的老年牙列缺损患者HeLD-14总分存在显著差异(P<0.05)。进一步的多因素线性回归分析结果表明,文化程度、年收入、吸烟习惯以及牙列缺损时间是影响老年牙列缺损患者口腔健康素养水平的显著独立因素(P<0.05)。结论老年牙列缺损患者其口腔健康素养处于中等水平HeLD-14总分[(44.15±10.80)分],其中文化程度、年收入、吸烟及牙列缺损时间是关键预测因子。建议以教育赋能、行为矫正与修复时效性为关键靶点构建精准化口腔健康干预体系,形成多要素协同干预路径。 展开更多
关键词 老年患者 牙列缺损 口腔健康素养 口腔健康 影响因素
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