期刊文献+
共找到21,746篇文章
< 1 2 250 >
每页显示 20 50 100
Curative effect of hydrogen peroxide combined with silver ion disinfection on pelvic floor dysfunction
1
作者 Wei Zhou Hua Guo 《World Journal of Clinical Cases》 SCIE 2024年第21期4508-4517,共10页
BACKGROUND Pelvic floor dysfunction(PFD)is related to muscle fiber tearing during childbirth,negatively impacting postpartum quality of life of parturient.Appropriate and effective intervention is necessary to promote... BACKGROUND Pelvic floor dysfunction(PFD)is related to muscle fiber tearing during childbirth,negatively impacting postpartum quality of life of parturient.Appropriate and effective intervention is necessary to promote PFD recovery.AIM To analyze the use of hydrogen peroxide and silver ion disinfection for vaginal electrodes in conjunction with comprehensive rehabilitation therapy for postpartum women with PFD.METHODS A total of 59 women with PFD who were admitted to the hospital from May 2019 to July 2022 were divided into two groups:Control group(n=27)received comprehensive rehabilitation therapy and observation group(n=32)received intervention with pelvic floor biostimulation feedback instrument in addition to comprehensive rehabilitation therapy.The vaginal electrodes were disinfected with hydrogen peroxide and silver ion before treatment.Intervention for both groups was started 6 weeks postpartum,and rehabilitation lasted for 3 months.Pelvic floor muscle voltage,pelvic floor muscle strength,vaginal muscle voltage,vaginal muscle tone,pelvic floor function,quality of life,and incidence of postpartum PFD were compared between the two groups.RESULTS Before comprehensive rehabilitation treatment,basic data and pelvic floor function were not significantly different between the two groups.After treatment,the observation group showed significant improvements in the maximum voltage and average voltage of pelvic floor muscles,contraction time of type I and type II fibers,pelvic floor muscle strength,vaginal muscle tone,vaginal muscle voltage,and quality of life(GQOLI-74 reports),compared with the control group.The observation group had lower scores on the pelvic floor distress inventory(PFDI-20)and a lower incidence of postpartum PFD,indicating the effectiveness of the pelvic floor biostimulation feedback instrument in promoting the recovery of maternal pelvic floor function.CONCLUSION The combination of the pelvic floor biostimulation feedback instrument and comprehensive rehabilitation nursing can improve pelvic floor muscle strength,promote the recovery of vaginal muscle tone,and improve pelvic floor function and quality of life.The use of hydrogen peroxide and silver ion disinfectant demonstrated favorable antibacterial efficacy and is worthy of clinical application. 展开更多
关键词 Pelvic floor biostimulation feedback instrument Comprehensive rehabilitation therapy Postpartum pelvic floor dysfunction Vaginal electrode Disinfection with hydrogen peroxide and silver ion Nanocolloidal silver
下载PDF
Restraint effect of partition wall on the tunnel floor heave in layered rock mass
2
作者 YANG Yunyun HUANG Da +2 位作者 ZHONG Zhu LIU Yang PENG Jianbing 《Journal of Mountain Science》 SCIE CSCD 2024年第7期2462-2479,共18页
The presence of horizontal layered rocks in tunnel engineering significantly impacts the stability and strength of the surrounding rock mass,leading to floor heave in the tunnel.This study focused on preparing layered... The presence of horizontal layered rocks in tunnel engineering significantly impacts the stability and strength of the surrounding rock mass,leading to floor heave in the tunnel.This study focused on preparing layered specimens of rock-like material with varying thickness to investigate the failure behaviors of tunnel floors.The results indicate that thin-layered rock mass exhibits weak interlayer bonding,causing rock layers near the surface to buckle and break upwards when subjected to horizontal squeezing.With an increase in the layer thickness,a transition in failure mode occurs from upward buckling to shear failure along the plane,leading to a noticeable reduction in floor heave deformation.The primary cause of significant deformation in floor heave is upward buckling failure.To address this issue,the study proposes the installation of a partition wall in the middle of the floor to mitigate heave deformation of the rock layers.The results demonstrate that the partition wall has a considerable stabilizing effect on the floor,reducing the zone of buckling failure and minimizing floor heave deformation.It is crucial for the partition wall to be sufficiently high to prevent buckling failure and ensure stability.Through simulation calculations on an engineering example,it is confirmed that implementing a partition wall can effectively reduce floor heave and enhance the stability of tunnel floor. 展开更多
关键词 Layered rock floor heave Horizontal compression test Failure behavior Partition wall
原文传递
Botulinum toxin type A injection combined with biofeedback in the treatment of spastic pelvic floor syndrome
3
作者 Fei-Fei Sun Yong-Qiang Chen +1 位作者 Zong-Lin Jiang Lin Ma 《World Journal of Clinical Cases》 SCIE 2024年第22期4905-4912,共8页
BACKGROUND Spastic pelvic floor syndrome(SPFS)is a refractory pelvic floor disease characterized by abnormal(uncoordinated)contractions of the external anal sphincter and puborectalis muscle during defecation,resultin... BACKGROUND Spastic pelvic floor syndrome(SPFS)is a refractory pelvic floor disease characterized by abnormal(uncoordinated)contractions of the external anal sphincter and puborectalis muscle during defecation,resulting in rectal emptation and obstructive constipation.The clinical manifestations of SPFS are mainly characterized by difficult defecation,often accompanied by a sense of anal blockage and drooping.Manual defecation is usually needed during defecation.From physical examination,it is commonly observed that the patient's anal muscle tension is high,and it is difficult or even impossible to enter with his fingers.AIM To investigate the characteristics of anorectal pressure and botulinum toxin A injection combined with biofeedback in treating pelvic floor muscle spasm syndrome.METHODS Retrospective analysis of 50 patients diagnosed with pelvic floor spasm syndrome.All patients underwent pelvic floor surface electromyography assessment,anorectal dynamics examination,botulinum toxin type A injection 100 U intramuscular injection,and two cycles of biofeedback therapy.RESULTS After the botulinum toxin A injection combined with two cycles of biofeedback therapy,the patient's postoperative resting and systolic blood pressure were significantly lower than before surgery(P<0.05).Moreover,the electromyography index of the patients in the resting stage and post-resting stages was significantly lower than before surgery(P<0.05).CONCLUSION Botulinum toxin A injection combined with biofeedback can significantly reduce pelvic floor muscle tension in treating pelvic floor muscle spasm syndrome.Anorectal manometry is an effective method to evaluate the efficacy of treatment objectively.However,randomized controlled trials are needed. 展开更多
关键词 Spastic pelvic floor syndrome Botulinum toxin A BIOFEEDBACK Anorectal pressure measurement Agachan constipation score
下载PDF
Basic Characteristics of an Appropriate Waste Fillers for Solvent Free and Water-Borne Industrial Polymer Floors and Their Utilization
4
作者 Jana Kosikova 《Journal of Civil Engineering and Architecture》 2024年第3期141-147,共7页
Recently the manufacture of epoxy coating and flooring materials begun to be under strong pressure to use more environmentally friendly raw materials in its composition.First tendency to reduce of solvents and diluent... Recently the manufacture of epoxy coating and flooring materials begun to be under strong pressure to use more environmentally friendly raw materials in its composition.First tendency to reduce of solvents and diluents contained in the materials appeared at the end of 90´s.This situation was supported by the Council of Europe in 2004 to reduce VOC emissions to zero till 2020.Solvent materials were thus largely replaced by solvent free materials from which the volatile substances are not released into the air.But pressure continued to increase,and over the past decade began to take centre stage water-based epoxy.On the Czech market solvent based material is still occasionally used,but predominant are solvent free materials.There are no commonly used materials containing wastes as fillers in new water-borne and solvent-free epoxy materials.Characteristics identification of the waste material as a potential filler is a set of properties that determine the limits of secondary raw materials or waste as a filler.This paper describes the basic characteristics which must be selected to meet the requirements,to affect negatively the workability,sedimentation,properties and behavior of the final floor system.Some materials must comply with special requirements,such as resistance to chemicals,etc.Next part of paper talks about utilization of polymer floors and their mechanical properties. 展开更多
关键词 Industrial polymer flooring materials waster fillers building materials
下载PDF
Further Analysis of Machine Tool Dimensional Accuracy and Thermal Stability under Varying Floor Temperature
5
作者 Joel Arumun Shadrack Abiola 《World Journal of Engineering and Technology》 2024年第2期258-273,共16页
Machining is as old as humanity, and changes in temperature in both the machine’s internal and external environments can be of great concern as they affect the machine’s thermal stability and, thus, the machine’s d... Machining is as old as humanity, and changes in temperature in both the machine’s internal and external environments can be of great concern as they affect the machine’s thermal stability and, thus, the machine’s dimensional accuracy. This paper is a continuation of our earlier work, which aimed to analyze the effect of the internal temperature of a machine tool as the machine is put into operation and vary the external temperature, the machine floor temperature. Some experiments are carried out under controlled conditions to study how machine tool components get heated up and how this heating up affects the machine’s accuracy due to thermally induced deviations. Additionally, another angle is added by varying the machine floor temperature. The parameters mentioned above are explored in line with the overall thermal stability of the machine tool and its dimensional accuracy. A Robodrill CNC machine tool is used. The CNC was first soaked with thermal energy by gradually raising the machine floor temperature to a certain level before putting the machine in operation. The machine was monitored, and analytical methods were deplored to evaluate thermal stability. Secondly, the machine was run idle for some time under raised floor temperature before it was put into operation. Data was also collected and analyzed. It is observed that machine thermal stability can be achieved in several ways depending on how the above parameters are joggled. This paper, in conclusion, reinforces the idea of machine tool warm-up process in conjunction with a carefully analyzed and established machine floor temperature variation for the approximation of the machine tool’s thermally stability to map the long-time behavior of the machine tool. 展开更多
关键词 Dimensional Accuracy Machine Tool Machine floor Thermal Stability TEMPERATURE Thermal Deviation
下载PDF
Maxillary sinus floor augmentation: a review of current evidence on anatomical factors and a decision tree 被引量:1
6
作者 Mingyue Lyu Dingyi Xu +1 位作者 Xiaohan Zhang Quan Yuan 《International Journal of Oral Science》 SCIE CAS CSCD 2023年第3期347-354,共8页
Maxillary sinus floor augmentation using lateral window and crestal technique is considered as predictable methods to increase the residual bone height;however,this surgery is commonly complicated by Schneiderian memb... Maxillary sinus floor augmentation using lateral window and crestal technique is considered as predictable methods to increase the residual bone height;however,this surgery is commonly complicated by Schneiderian membrane perforation,which is closely related to anatomical factors.This article aimed to assess anatomical factors on successful augmentation procedures.After review of the current evidence on sinus augmentation techniques,anatomical factors related to the stretching potential of Schneiderian membrane were assessed and a decision tree for the rational choice of surgical approaches was proposed.Schneiderian membrane perforation might occur when local tension exceeds its stretching potential,which is closely related to anatomical variations of the maxillary sinus.Choice of a surgical approach and clinical outcomes are influenced by the stretching potential of Schneiderian membrane.In addition to the residual bone height,clinicians should also consider the stretching potential affected by the membrane health condition,the contours of the maxillary sinus,and the presence of antral septa when evaluating the choice of surgical approaches and clinical outcomes. 展开更多
关键词 STRETCHING floor TREE
下载PDF
Minimally invasive techniques for lateral maxillary sinus floor elevation: small lateral window and one-stage surgery—a 2–5-year retrospective study
7
作者 Shaojingya Gao Yao Jiang +2 位作者 Yangxue Yao Songhang Li Xiaoxiao Cai 《International Journal of Oral Science》 SCIE CAS CSCD 2023年第3期401-410,共10页
This study aimed to introduce a minimally invasive technique for maxillary sinus floor elevation using the lateral approach(lSFE)and to determine the factors that influence the stability of the grafted area in the sin... This study aimed to introduce a minimally invasive technique for maxillary sinus floor elevation using the lateral approach(lSFE)and to determine the factors that influence the stability of the grafted area in the sinus cavity.Thirty patients(30 implants)treated with lSFE using minimally invasive techniques from 2015 to 2019 were included in the study.Five aspects of the implant(central,mesial,distal,buccal,and palatal bone heights[BHs])were measured using cone-beam computed tomography(CBCT)before implant surgery,immediately after surgery(T0),6 months after surgery(T1),and at the last follow-up visit(T2).Patients’characteristics were collected.A small bone window(height,(4.40±0.74)mm;length,(6.26±1.03)mm)was prepared.No implant failed during the follow-up period(3.67±1.75)years.Three of the 30 implants exhibited perforations.Changes in BH of the five aspects of implants showed strong correlations with each other and BH decreased dramatically before second-stage surgery.Residual bone height(RBH)did not significantly influence BH changes,whereas smoking status and type of bone graft materials were the potentially influential factors.During the approximate three-year observation period,lSFE with a minimally invasive technique demonstrated high implant survival rate and limited bone reduction in grafted area.In conclusion,lSFE using minimally invasive techniques was a viable treatment option.Patients who were nonsmokers and whose sinus cavity was filled with deproteinized bovine bone mineral(DBBM)had significantly limited bone resorption in grafted area. 展开更多
关键词 SURGERY viable floor
下载PDF
Experimental Mode and Vibration Comfort Analysis of High-Rise Glulam Building Floor Structure
8
作者 Yuhang He Rongzhuo Zhang +1 位作者 Yifan Zhang Zheng Wang 《Journal of Renewable Materials》 SCIE EI 2023年第6期2729-2743,共15页
In order to better meet the objective requirements of the use safety of the high-rise glulam building floor structure and the living comfort of the residents,the transient excitation,environmental excitation and frequ... In order to better meet the objective requirements of the use safety of the high-rise glulam building floor structure and the living comfort of the residents,the transient excitation,environmental excitation and frequency spectrum identification methods were used to carry out experimental modal test in-site on the three rooms numbered A,B and C of the same glulam structural building.The three rooms have different functions,different floor sizes and different floor supporting structures.The research results have shown that the first-order bending frequency of the floor structure of Room A is 27.50 Hz,the transverse second-order bending frequency is 34.75 Hz,the longitudinal second-order bending frequency is 53.25 Hz,and the first-order torsional frequency is 56.25 Hz.The reinforced wooden beam at the bottom of the floor of Room A increases the transverse stiffness of the floor structure,but does not offset the anisotropy caused by the longitudinally installed glulam floors.The fundamental frequency values of the floor structures of the three rooms numbered A,B,and C are 27.5,13 and 18 Hz,respectively.This has a relatively high innovation and reference significance for integrating the theory of structural dynamic characteristics with the dynamic testing technology,improving the design level of high-rise glulam structure buildings,and improving the living comfort of residents. 展开更多
关键词 Glulam building wooden floor experimental mode vibration comfort fundamental frequency
下载PDF
Reporting Children’s Development below the Test Floor: Looking Back and Forth to Describe Individual Strengths and Needs
9
作者 Elizabeth M. Green Louise A. Stroud 《Health》 CAS 2023年第2期122-133,共12页
The test floor effects seen in standardised tests lead to a standardised score of 1 or less with a flat profile that hides a child’s individual strengths and needs. The Griffiths III community of practitioners reques... The test floor effects seen in standardised tests lead to a standardised score of 1 or less with a flat profile that hides a child’s individual strengths and needs. The Griffiths III community of practitioners requested advice on the reporting of children’s development below the floor of the test, so that individual strengths and needs can be described. This paper reports the third phase of research following an earlier Scoping Review and a wider literature review. To confirm quality control, Phase 3 was conducted in a retrospective manner using the same methodology as the earlier phases but in a reverse direction. Peer reviewer comments and key elements from the Scoping Review and keywords from the publications were tabulated. Data analysis included a change of perspective to that of the child and their individual rights with respect to the literature themes already described in Phase 2. These confirmed that there is little specific guidance in the literature, but that computational advances for homogeneous populations and especially disaggregated data offer some solutions. A greater balance between broad biopsychosocial models and standardised models of assessment should be sought by practitioners together with the use of disaggregated data to highlight issues that pertain to individual subsets of results. This will ensure that the child’s right for their individual strengths and needs to be described together with a plan for management, may be met. 展开更多
关键词 Developmental Assessment Children with Severe Disability Disaggregated Data Pattern and Needs Identification Below Test floor
下载PDF
Effects of High Risk Pregnancy Factors on Pelvic Floor Muscle Weakness and Changes of PG, ACTH and CRP
10
作者 Yu Han Haiyan Lin +6 位作者 Jiu Du Lianfang Chen Xianmei Wei Peijia Wei Biyun Zhou Xiangli Feng Siran Chen 《Open Journal of Obstetrics and Gynecology》 2023年第9期1569-1579,共11页
Objective: To investigate the effects of different delivery modes on perinatal pelvic floor muscle strength, PG, ACTH and CRP of high-risk pregnant women. Methods: 380 high-risk pregnant women who gave birth in our ho... Objective: To investigate the effects of different delivery modes on perinatal pelvic floor muscle strength, PG, ACTH and CRP of high-risk pregnant women. Methods: 380 high-risk pregnant women who gave birth in our hospital from March 2021 to February 2022 were selected as subjects, including 100 vaginal natural delivery, 156 forceps assisted delivery and 124 cesarean section. Pelvic floor pressure, PG, ACTH, CRP, IL-6, TNF-α and IL-4, IL-10 levels were evaluated and compared. The perinatal occurrence of pelvic floor functional disease (PFD) in high-risk pregnant women in each group was analyzed and evaluated. Results: There were statistical differences in the amount of postpartum blood loss (P 0.0001, F = 99.01), postpartum blood loss 24 h (P = 0.0004, F = 19.54) and hospital stay (P 0.0001, F = 70.81) among the three groups of high-risk women in natural vaginal delivery, forceps delivery and cesarean section. In addition, there were 72, 134 and 70 cases of abnormal pelvic floor fatigue in natural vaginal delivery, forceps assisted delivery and cesarean section (P 0.0001, χ<sup>2</sup> = 30.16). There were 36, 79 and 21 cases of muscle injury, respectively (P 0.0001, χ<sup>2</sup> = 34.16). There were 49, 98 and 43 cases of dysmuscular contraction, respectively (P 0.0001, χ<sup>2</sup> = 21.94). There were 65, 120 and 41 cases with vaginal dynamic pressure 80 cm H<sub>2</sub>O (P 0.0001, χ<sup>2</sup> = 56.86), respectively. The. 展开更多
关键词 High-Risk Pregnant Women Pelvic floor Muscle Strength Stress Response Inflammatory Response
下载PDF
Two Cases of Epidermoid Cyst of the Buccal Floor Simulating: A Tumour of the Submandibular Gland
11
作者 Aminata Mbaye Ndeye Fatou Thiam +3 位作者 Ababacar Diegane Faye Mouminatou Seye Houra Ahmed Cire Ndiaye 《International Journal of Otolaryngology and Head & Neck Surgery》 2023年第5期301-308,共8页
Dermoid cyst of the oral floor is rare benign tumour, who having three histological aspects: dermoid, teratoid and epidermoid. This one is characterized by the presence of a squamous stratified epithelium with cutaneo... Dermoid cyst of the oral floor is rare benign tumour, who having three histological aspects: dermoid, teratoid and epidermoid. This one is characterized by the presence of a squamous stratified epithelium with cutaneous remnants. It may occur in any part of the body, however their frequency in the ENT sphere is relatively scarce. Seven per cent (7%) only of epidermoid cysts occur in the cervico-facial area, 1.6% of which locate at the floor level. When they are located submandibular, they can pose diagnostic difficulties and look like a tumour of the submaxillary gland. We report two cases of epidermoid cyst of the floor. Both patients suffered from swelling of the submandibular gland. Magnetic Resonance Imaging was not requested due to lack of resources. However, surgery allowed in both cases the excision of a cyst next to a normal submandibular gland. Patients did well post operatively. 展开更多
关键词 Epidermoid Cyst Mouth floor Submandibular Gland SURGERY TUMOUR
下载PDF
Suitable retention and recovery technology of floor coal at ends of fully mechanized face with great mining heights 被引量:3
12
作者 Zhang Nenghu Wu Qi +1 位作者 YuanYong Bai Qingsheng 《Mining Science and Technology》 EI CAS 2011年第2期281-285,共5页
Gateways at faces of great mining heights are mostly driven along the roof of coal seams.For gateway height restrictions,a 1-3 m floor coal is retained,leaving a triangular floor coal at the face ends,causing a loss o... Gateways at faces of great mining heights are mostly driven along the roof of coal seams.For gateway height restrictions,a 1-3 m floor coal is retained,leaving a triangular floor coal at the face ends,causing a loss of coal.In order to improve coal recovery rates and to ensure efficiency of equipment at coal mining faces,we investigated suitable retention methods and recovery technology of floor coal at face ends.The upper floor coal can directly be recovered by a shearer with floor dinting.The lower floor coal is recovered by shearer with floor dinting after advanced floor dinting and retaining a step for protecting coal sides in a haulage gateway.Field practice shows that this method can improve the coal recovery rates at fully mechanized working faces with great mining heights. 展开更多
关键词 Great mining heights floor coal at face ends floor coal recovery floor dinting Step for protecting coal side
下载PDF
Experimental study of low-temperature electrical radiant floor heating system
13
作者 孔祥强 李瑛 胡松涛 《Journal of Southeast University(English Edition)》 EI CAS 2010年第2期287-291,共5页
To evaluate the thermal performance of a low-temperature electrical radiant floor heating system,an experimental facility equipped with a constant temperature chamber and different specimen floors is designed and buil... To evaluate the thermal performance of a low-temperature electrical radiant floor heating system,an experimental facility equipped with a constant temperature chamber and different specimen floors is designed and built.The heating cable is installed in the floor slab with a unit-rated power of 30 W/m.Twenty-four different schemes are worked out and tested,which include three kinds of composite floor structures and eight kinds of cable distances.The cable distances are 30,40,50,60,80,100,130,150 mm.The main affective factors of the thermal performance and their influencing regularity are discussed.The experimental results show that the system has good stability and reliability,and the ratio of the radiation heat-transfer rate to the gross heat-transfer rate is greater than 50%.When the floor structure and the cable distance are fixed,the gross heat-transfer rate of the upper floor surface has a maximum value at an optimal cable distance.Under the experimental conditions in this paper,the optimal cable distance is 50 mm. 展开更多
关键词 electrical radiant floor heating floor structure cable distance thermal performance
下载PDF
Application of the coal mine floor rating(CMFR)to assess the floor stability in a Central Appalachian Coal Mine 被引量:1
14
作者 Sena Cicek Ihsan Berk Tulu +2 位作者 Mark Van Dyke Ted Klemetti Joe Wickline 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2021年第1期83-89,共7页
Estimating the overall floor stability in a coal mine using deterministic methods which require complex engineering properties of floor strata is desirable,but generally it is impractical due to the difficulty of gath... Estimating the overall floor stability in a coal mine using deterministic methods which require complex engineering properties of floor strata is desirable,but generally it is impractical due to the difficulty of gathering essential input data.However,applying a quantitative methodology to describe floor quality with a single number provides a practical estimate for preliminary assessment of floor stability.The coal mine floor rating(CMFR)system,developed by the University of New South Wales(UNSW),is a rockmass classification system that provides an indicator for the competence of floor strata.The most significant components of the CMFR are uniaxial compressive strength and discontinuity intensity of floor strata.In addition to the competence of the floor,depth of cover and stress notch angle are input parameters used to assess the preliminary floor stability.In this study,CMFR methodology was applied to a Central Appalachian Coal Mine that intermittently experienced floor heave.Exploratory drill core data,overburden maps,and mine plans were utilized for the study.Additionally,qualitative data(failure/non-failure)on floor conditions of the mine entries near the core holes was collected and analyzed so that the floor quality and its relation to entry stability could be estimated by statistical methods.It was found that the current CMFR classification system is not directly applicable in assessing the floor stability of the Central Appalachian Coal Mine.In order to extend the applicability of the CMFR classification system,the methodology was modified.A calculation procedure of one of the CMFR classification system’s components,the horizontal stress rating(HSR),was changed and new parameters were added to the HSR. 展开更多
关键词 Rock mass classification Coal mine floor rating(CMFR) floor heave floor failure Buckling failure mechanism
下载PDF
Turbulence regime near the forest floor of a mixed broad leaved/Korean pine forest in Changbai Mountains 被引量:5
15
作者 张军辉 丁之慧 +2 位作者 韩士杰 邹春静 周玉梅 《Journal of Forestry Research》 SCIE CAS CSCD 2002年第2期119-122,164,共4页
The measurement and observation for this study were carried out by using a three-dimensional (u, v, w) Sonic anemometer (IAP-SA 485), at Forest Ecosystem Opened Research Station of Changbai Mountains (12828扙 and 4224... The measurement and observation for this study were carried out by using a three-dimensional (u, v, w) Sonic anemometer (IAP-SA 485), at Forest Ecosystem Opened Research Station of Changbai Mountains (12828扙 and 4224?N, Jilin Province, P. R. China) in August 2001. The basic characteristics of turbulence, such as turbulence intensity, atmospheric stability, time scales, and convection state, near the forest floor were analyzed. It is concluded that the airflow near forest floor is characterized by high intermittence and asymmetry, and the active and upward movement takes the leading position. Near forest floor, the vertical turbulence is retained and its time scale and length scale are much less than that of u, v components. The eddy near forest floor shows a flat structure and look like a ’Disk’. Buoyancy plays a leading role in the generation and maintenance of local turbulence 展开更多
关键词 Forest floor Velocity statistics Atmospheric stability Convection states
下载PDF
A HOLONIC FRAMEWORK OF RECONFIGURABLE SHOP FLOOR CONTROL SYSTEMS IN AUTOMATED MANUFACTURING SYSTEMS 被引量:4
16
作者 周燕飞 姬鹏华 +1 位作者 范澄 冷晟 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1999年第1期61-69,共9页
The agility and the flexibility of the current shop floor control systems have been limited so far, owing to the lack of structural flexibility and agility in its control software layer. Most of them are based on trad... The agility and the flexibility of the current shop floor control systems have been limited so far, owing to the lack of structural flexibility and agility in its control software layer. Most of them are based on traditional hierarchical architecture and the top down approach and depend structurally on their specific configuration and job scheduling. Not only can they hardly satisfactorily adapt to these increasing changes and disturbances, but also make the redevelopment and maintenance of shop floor control system (SFCS) to need high cost and much time. And SFCS based on the heterarchical architecture don′t provide a predictable and high performance system, especially not in the heterogeneous environments, where the resources are scarce and the current decisions have serious repercussions on the future performances. For this reason, the heterarchical control is hardly applied in industry. Obviously, it is necessary to develop a new structural framework of reconfigurable SFCS to improve their agility, flexibility and maintainability. This paper presents a holonic framework of reconfigurable SFCS based on holonic manufacturing concepts. The framework is composed of resource holons, product holons and other staff holons. The model of each holon and the co operative mechanisms of holons are described. To verify the proposed approach experimentally, a prototype reconfigurable SFCS for a flexible manufacturing shop floor producing discrete parts is implemented. 展开更多
关键词 holarchy automated manufacturing system shop floor control control system
下载PDF
Floor stress evolution laws and its effect on stability of floor roadway 被引量:20
17
作者 Zhang Hualei Cao Jianjun Tu Min 《International Journal of Mining Science and Technology》 SCIE EI 2013年第5期631-636,共6页
According to the distribution of abutment stress in a stope,this research established the mechanical model of mining abutment pressure transmission in floor base on the theory of semi-infnite plate body in elasticity.... According to the distribution of abutment stress in a stope,this research established the mechanical model of mining abutment pressure transmission in floor base on the theory of semi-infnite plate body in elasticity.This study takes the 762 working face of Haizi Coal Mine as a case in point,and analyzed the dynamic evolution law of seam floor stress during the mining process.With an organic combination of the mining floor stress and surrounding rock stress,the study obtained the change laws of the maximum principle stress and the minimum one for the floor roadway surrounding rock when mining the upper working face.Considering the non-constant pressure force state and the cracks revolution mechanisms of floor roadway surrounding rock,the research built the mechanical model of roadway stress.Simulation results verify the reliability of the above conclusions.Moreover,this model could provide the theoretical basis and technical support for controlling floor roadway surrounding rock. 展开更多
关键词 floor Mining abutment pressure floor roadway Cracks evolution mechanisms
下载PDF
Mechanical model of water inrush from coal seam floor based on triaxial seepage experiments 被引量:35
18
作者 Yihui Pang Guofa Wang Ziwei Ding 《International Journal of Coal Science & Technology》 EI CAS 2014年第4期428-433,共6页
In order to study the mechanism of confined water inrush from coal seam floor,the main influences on permeability in the process of triaxial seepage experiments were analyzed with methods such as laboratory experiment... In order to study the mechanism of confined water inrush from coal seam floor,the main influences on permeability in the process of triaxial seepage experiments were analyzed with methods such as laboratory experiments,theoretical analysis and mechanical model calculation.The crack extension rule and the ultimate destruction form of the rock specimens were obtained.The mechanism of water inrush was explained reasonably from mechanical point of view.The practical criterion of water inrush was put forward.The results show that the rock permeability "mutation" phenomenon reflects the differences of stress state and cracks extension rate when the rock internal crack begins to extend in large-scale.The rock ultimate destruction form is related to the rock lithology and the angle between crack and principal stress.The necessary condition of floor water inrush is that the mining pressure leads to the extension and transfixion of the crack.The sufficient condition of floor water inrush is that the confined water’s expansionary stress in normal direction and shear stress in tangential direction must be larger than the internal stress in the crack.With the two conditions satisfied at the same time,the floor water inrush accident will occur. 展开更多
关键词 Triaxial permeability experiment floor water innush model floor water inrush mechanism Necessary and sufficient conditions of water inrush
下载PDF
Concentrations and seasonal dynamics of dissolved organic carbon in forest floors of two plantations (Castanopsis kawakamii and Cunninghamia lanceolata) in subtropical China 被引量:7
19
作者 ZHANG Jiang-shan GUO Jian-fen +1 位作者 CHEN Guang-shui QIAN Wei 《Journal of Forestry Research》 SCIE CAS CSCD 2005年第3期205-208,共4页
The concentrations and seasonal dynamics of DOC in forest floors of monoculture plantations of Castanopsis kawakamii and Chinese fir (Cunninghamia lanceolata) were assessed in Sanming, Fujian, China (26°11′30... The concentrations and seasonal dynamics of DOC in forest floors of monoculture plantations of Castanopsis kawakamii and Chinese fir (Cunninghamia lanceolata) were assessed in Sanming, Fujian, China (26°11′30″N, 117°26′00″E). Forest floor samples were taken in January, April, July and October in 2002 and divided into undecomposed material (horizon Oi), partially decomposed organic material (horizon Oe), and fully decomposed organic material (horizon Oa). Upon collection. DOC concentrations of samples were analyzed by a High Temperature TOC. The results showed that the annual average DOC concentration of Chinese fir (1341.7 mg·kg^-1) in the forest floor was higher than that of Castanopsis kawakamii ( 1178.9 mg·kg^-1). Difference in DOC concentrations was observed among three horizons of the forest floor. DOC concentration of forest floor in the two forests was the highest in horizon Oe. Seasonal trends of DOC concentrations in different horizons of forest floors were similar and the maximal value occurred in autumn (or winter). The concentration and temporal change of DOC in studied forests were probably related to the variation in moisture, temperature, biological activity and quantity of organic matter in the forest floor. 展开更多
关键词 Dissolved organic carbon (DOC) Seasonal dynamics Forest floor Castanopsis kawakamii Cunninghamia lanceolata matter in the forest floor.
下载PDF
Experimental investigation on heat transfer characteristics of a new radiant floor system with phase change material 被引量:1
20
作者 夏燚 张小松 《Journal of Southeast University(English Edition)》 EI CAS 2015年第4期496-500,共5页
In order to improve the heat transfer characteristics of the traditional phase change material(PCM) floor, a new double-layer radiant floor system with PCM is proposed, which can store thermal or cold energy in the ... In order to improve the heat transfer characteristics of the traditional phase change material(PCM) floor, a new double-layer radiant floor system with PCM is proposed, which can store thermal or cold energy in the off-peak period and use them in the peak period. An experimental setup was developed to study the heat transfer characteristics of the new system under both cooling and heating modes. The experimental results show that the double-layer radiant floor system with PCM can meet both the cold and thermal requirements of users. Moreover, with the same duration of the thermal energy storage process, the increase of water temperature supplied to the system can improve the heat transfer characteristics of the system but lead to the discomfort of users. On the other hand, if the air temperature at the end of the thermal energy storage process is the same under different conditions, the increase of supplied water temperature will decrease the thermal energy storage time and ensure the comfort of users. 展开更多
关键词 ENERGY-SAVING radiant floor phase changematerial DOUBLE-LAYER heat transfer characteristics
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部