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Investigation of Experimental Devices for Finger Active and Passive Tactile Friction Analysis
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作者 Xue Zhou Marc A.Masen +3 位作者 Jiliang Mo Xinyu Shi Yaosheng He Zhongmin Jin 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第2期129-139,共11页
Complicated tribological behavior occurs when human fingers touch and perceive the surfaces of objects.In this process,people use their exploration style with different conditions,such as contact load,sliding speed,sl... Complicated tribological behavior occurs when human fingers touch and perceive the surfaces of objects.In this process,people use their exploration style with different conditions,such as contact load,sliding speed,sliding direction,and angle of orientation between fingers and object surface consciously or unconsciously.This work addressed interlaboratory experimental devices for finger active and passive tactile friction analysis,showing two types of finger movement.In active sliding experiment,the participant slid their finger freely against the object surface,requiring the subject to control the motion conditions themselves.For passive sliding experiments,these motion conditions were adjusted by the device.Several analysis parameters,such as contact force,vibration acceleration signals,vibration magnitude,and fingerprint deformation were recorded simultaneously.Noticeable friction differences were observed when comparing active sliding and passive sliding.For passive sliding,stick-slip behavior occurred when sliding in the distal direction,evidenced by observing the friction force and the related deformation of the fingerprint ridges.The employed devices showed good repeatability and high reliability,which enriched the design of the experimental platform and provided guidance to the standardization research in the field of tactile friction. 展开更多
关键词 Finger friction Experimental device active sliding passive sliding Rotating
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Task-Oriented Topology System Synthesis of Reconfigurable Legged Mobile Lander Integrating Active and Passive Metamorphoses
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作者 Youcheng Han Ziyue Li +3 位作者 Gaohan Zhu Weizhong Guo Jianzhong Yang Wei Liu 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2023年第3期89-109,共21页
To explore hostile extraterrestrial landforms and construct an engineering prototype,this paper presents the task-oriented topology system synthesis of reconfigurable legged mobile lander(ReLML)with three operation mo... To explore hostile extraterrestrial landforms and construct an engineering prototype,this paper presents the task-oriented topology system synthesis of reconfigurable legged mobile lander(ReLML)with three operation modes from adjusting,landing,to roving.Compared with our preceding works,the adjusting mode with three rotations(3R)provides a totally novel exploration approach to geometrically matching and securely arriving at complex terrains dangerous to visit currently;the landing mode is redefined by two rotations one translation(2R1T),identical with the tried-and-tested Apollo and Chang'E landers to enhance survivability via reasonable touchdown buffering motion;roving mode also utilizes 2R1T motion for good motion and force properties.The reconfigurable mechanism theory is first brought into synthesizing legged mobile lander integrating active and passive metamorphoses,composed of two types of metamorphic joints and metamorphic execution and transmission mechanisms.To reveal metamorphic principles with multiple finite motions,the finite screw theory is developed to present the procedure from unified mathematical representation,modes and source phase derivations,metamorphic joint and limb design,to final structure assembly.To identify the prototype topology,the 3D optimal selection matrix method is proposed considering three operation modes,five evaluation criteria,and two topological subsystems.Finally,simulation verifies the whole task implementation process to ensure the reasonability of design. 展开更多
关键词 Legged mobile lander Topology synthesis active and passive metamorphoses Finite screw Metamorphic joint Reconfigurable mechanism
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Exploring Passive Exoskeleton-Induced Changes in Lumbar Muscle Activity
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作者 Ryo Fujitani Hiroko Kawasaki +7 位作者 Mika Suzuki Shogo Sakai Souma Hori Ryoga Muranishi Shinichi Noguchi Takumi Jiroumaru Michio Wachi Kouhei Okuyama 《Open Journal of Therapy and Rehabilitation》 2023年第4期149-157,共9页
Purpose: The purpose of this study was to evaluate the effect of using a passive exoskeleton on lumbar muscle activity during lifting movements, and to determine whether muscle activity remains altered after exoskelet... Purpose: The purpose of this study was to evaluate the effect of using a passive exoskeleton on lumbar muscle activity during lifting movements, and to determine whether muscle activity remains altered after exoskeleton removal. This study sought to identify the potential risks and benefits associated with the use of passive exoskeletons for the prevention and treatment of low back pain. Methods: Eighteen healthy adult participants lifted a 10 kg suitcase while wearing a passive exoskeleton. Muscle activity and postures were measured during lifting and before, during, and after exoskeleton use. This study examined whether the reduced muscle activity observed during exoskeleton use persisted after exoskeleton removal. Muscle activity was assessed using electromyography and postures were recorded using reflective markers and a camera. Results: The study found that Lumbar muscle activity decreased significantly (approximately 40%) during exoskeleton use compared to that without exoskeleton use. Importantly, lumbar muscle activity remained low after exoskeleton removal, at levels similar to those observed during exoskeleton use. This suggests that individuals adapted to the exoskeleton support and maintained altered muscle control, even without the exoskeleton. Conclusion: This study demonstrates that passive exoskeletons significantly reduce lumbar muscle activity during lifting tasks, and that this altered muscle control persists after exoskeleton removal. These findings contribute to the understanding of the risks and benefits of passive exoskeletons, potentially aiding their development and informing their use in the prevention and treatment of low back pain. 展开更多
关键词 passive Exoskeleton Low Back Pain Muscle activity ADAPTATION
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To explore patients’ perceptions about motivators and barriers of adherence to highly active antiretroviral therapy among people living with HIV: A qualitative study
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作者 Sonia GULATI Hariprasath PANDURANGAN Pulin Kumar GUPTA 《Journal of Integrative Nursing》 2023年第4期256-265,共10页
Objective:For people living with HIV(PLHIV),strict adherence to highly active antiretroviral therapy(HAART)is the key to effective treatment and retention in human immunodeficiency virus(HIV)care.There are many factor... Objective:For people living with HIV(PLHIV),strict adherence to highly active antiretroviral therapy(HAART)is the key to effective treatment and retention in human immunodeficiency virus(HIV)care.There are many factors which promote or halt the antiretroviral therapy(ART)adherence practices.Therefore,the present study aimed to examine the HAART adherence levels and to explore patients’views about barriers and facilitators to HIV treatment adherence.Methods:Semi-structured interviews were conducted among 15 PLHIV at the ART clinic of Dr.Ram Manohar Lohia Hospital,New Delhi.Interviews were audio-recorded in the local Hindi language,and bilingual experts(English and Hindi)transcribed verbatim.Qualitative data were coded for themes and subthemes and analyzed using a phenomenological approach as per thematic content analysis.Results:Feeling of hopelessness,delayed ART initiation,difficult initial phase of ART,forget to take ART on time,fear of disclosure of HIV diagnosis,lack of privacy and negative social support,and impact of lockdown due to COVID-19 were revealed as significant barriers to ART adherence.At the same time,commitment to raise and educate children,ART to increase life span,maintain oneself to be physically fit and healthy,only a single pill per day,very supportive counselors and health-care professionals,and hope to give birth to a healthy child were identified as facilitators of HIV retention.Conclusion:Understanding patient’s perception about ART adherence,its motivational and barrier factors which are directly affecting ART adherence and retention of PLHIV in HIV treatment and follow-ups are of utmost importance to improve ART adherence during HIV patient care services. 展开更多
关键词 ADHERENCE barriers highly active antiretroviral therapy human immunodeficiency virus motivATORS PERCEPTIONS
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A Study of Motivation in Active Performance in Class
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作者 赵晨 《科技视界》 2013年第12期91-91,共1页
Motivation was advanced by several researchers when talking of enhancing students' active class performance with better study efficiency and outcome. This essay would make the definitions and the classifications o... Motivation was advanced by several researchers when talking of enhancing students' active class performance with better study efficiency and outcome. This essay would make the definitions and the classifications of motivation in active and negative class performance. 展开更多
关键词 学生 学习效率 学习方法 教学方法
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Effects of active and passive training apparatus combined with rehabilitation training on lower limb function of stroke patients during recovery period 被引量:1
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作者 Yang Tian Lanfang Shi +3 位作者 Lei Jing Le Li Bin Chen Ke wei Zhao 《Neural Regeneration Research》 SCIE CAS CSCD 2007年第10期636-640,共5页
Stroke patients always spontaneously do some learning and training of motor functions; however, learning and training are not prompt and right, while patients do not have enough activity amounts. Active and passive mo... Stroke patients always spontaneously do some learning and training of motor functions; however, learning and training are not prompt and right, while patients do not have enough activity amounts. Active and passive motor training apparatus is aimed directly at lower limb training so as to stimulate nerve function through stimulating muscular movement. Based on motor mileage, motor time, various power supplies and velocity of active and passive training apparatus, we can understand the training condition and adjust training program. OBJECTIVE: To observe the effects of grade-III rehabilitation training combining with active and passive training apparatus on lower limb function, muscle strength and activity of daily living (ADL) in stroke patients during recovery period. DESIGN: Contrast observation. SETTING: Department of Rehabilitation, Jilin Academic Institute of Traditional Chinese Medicine. PARTICIPANTS: A total of 80 patients with stroke-induced hemiplegia after stabilizing vital signs for 2 weeks were selected from Department of Rehabilitation, Jilin Academic Institute of Traditional Chinese Medicine from January to June 2007. There were 47 males and 33 females, and their ages ranged from 41 to 75 years. All patients met the diagnostic criteria of the Fourth National Cerebrovascular Disease Academic Meeting in 1995 and were diagnosed as cerebral hemorrhage or cerebral infarction through CT or MRI examinations in clinic. Patients and their parents provided the confirmed consent. Based on therapeutic orders of hospitalization, patients were randomly divided into treatment group and control group with 40 patients in each group. METHODS: Patients in the control group received physical therapy and occupational therapy combining with rehabilitative treatment based on grade-III rehabilitative treatment program, which was set by the National Cerebrovascular Disease Topic Group. In addition, patients in the treatment group were trained with active and passive motor training apparatus based on therapeutic procedures in the control group. The active and passive motor training apparatus was designed as the therapeutic style of nervous system; otherwise, the treatment was performed once a day, 30 minutes once and 6 times per week. Four weeks were regarded as a course. MAIN OUTCOME MEASURES: Before treatment, at 2 weeks after treatment and after the first course, bare-handed muscle strength examination was used to check muscle strength and muscular tension; in addition, simple Fugl-Meyer assessment (FMA) and diagnostic criteria which were set by the Fourth National Cerebrovascular Disease Academic Meeting were used to evaluate motor function of limbs and total ADL. RESULTS: All 80 stroke patients were involved in the final analysis. ① Muscle strength of lower limbs was improved in both treatment group and control group. After the first course, muscle strength in the treatment group was obviously superior to that in the control group ( x^2=6.64, P 〈 0.05). ② After the first course, Fugl-Meyer scores in the treatment group were higher than those in the control group, and there was significant difference (t =2.82, P 〈 0.05). ③ Muscular tension of lower limbs was not changed in both treatment group and control group after treatment (P 〉 0.05). ④ After the first course, ADL in the treatment group was superior to that in the control group (P 〈 0.05). Among patients in the treatment group, 24 cases (60%) had obvious progress, 16 (40%) had progress, and 0 (0%) did not have any changes. On the other hand, among patients in the control group, 13 cases (32.5%) had obvious progress, 26 (65%) had progress, and 1 (2.5%) did not have any changes. CONCLUSION: Rehabilitation training combining with active and passive motor training apparatus can promote the recovery of lower limb disorder, increase muscle strength, control spasm, improve ADL and cause satisfactorily clinical effects in stroke patients during recovery period. 展开更多
关键词 active and passive training apparatus STROKE HEMIPLEGIA rehabilitation training
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Detection efficiency characteristics of free-running InGaAs/InP single photon detector using passive quenching active reset IC 被引量:1
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作者 郑福 王超 +1 位作者 孙志斌 翟光杰 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第1期460-464,共5页
InGaAs/InP avalanche photodiodes (APD) are rarely used in a free-running regime for near-infrared single photon detection. In order to overcome the detrimental afterpulsing, we demonstrate a passive quenching active... InGaAs/InP avalanche photodiodes (APD) are rarely used in a free-running regime for near-infrared single photon detection. In order to overcome the detrimental afterpulsing, we demonstrate a passive quenching active reset integrated circuit. Taking advantage of the inherent fast passive quenching process and active reset to reduce reset time, the integrated circuit is useful for reducing afterpulses and is also area-efficient. We investigate the free-running single photon detector's afterpulsing effect, de-trapping time, dark count rate, and photon detection efficiency, and also compare with gated regime operation. After correction for deadtime and afterpulse, we find that the passive quenching active reset free-running single photon detector's performance is consistent with gated operation. 展开更多
关键词 single photon detector free-running passive quenching active reset
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Hybrid Passive/Active Vibration Control of a Loosely Connected Spacecraft System 被引量:3
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作者 Xin Wang Xiaokui Yue +1 位作者 Haowei Wen Jianping Yuan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第1期61-87,共27页
In this paper,a hybrid passive/active vibration(HPAV)controller of a loosely connected spacecraft consisting of a servicing satellite,a target and an X-shape structure isolator is first proposed to suppress vibrations... In this paper,a hybrid passive/active vibration(HPAV)controller of a loosely connected spacecraft consisting of a servicing satellite,a target and an X-shape structure isolator is first proposed to suppress vibrations of the system when subjected to the impulsive external excitations during the on-orbit missions.The passive dynamic response of the combined system can be adjusted appropriately to achieve the desired vibration isolation performance by tuning the structural parameters of the bio-inspired X-shape structure.Moreover,the adaptive control design through dynamic scaling technique is selected as the active component to maintain high vibration isolation performance in the presence of parameter uncertainties such as mass of the satellite platform,the damping and rotation friction coefficients of the X-shape structure.Compared with the pure passive system and the traditional spring-mass-damper(SMD)isolator,the HPAV strategy witnesses lower transmissibility,smaller vibration amplitude and higher convergence rate when subjected to the post-capture impact.Numerical simulations demonstrate the feasibility and validity of the proposed hybrid control scheme in suppressing vibrations of the free-floating spacecraft. 展开更多
关键词 Hybrid passive/active vibration control X-shape structure adaptive control on-orbit capture
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HPR1000: Advanced Pressurized Water Reactor with Active and Passive Safety 被引量:24
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作者 Ji xing Daiyong Song Yuxiang Wu 《Engineering》 SCIE EI 2016年第1期79-87,共9页
HPR1000 is an advanced nuclear power plant(NPP)with the significant feature of an active and passive safety design philosophy,developed by the China National Nuclear Corporation.On one hand,it is an evolutionary desig... HPR1000 is an advanced nuclear power plant(NPP)with the significant feature of an active and passive safety design philosophy,developed by the China National Nuclear Corporation.On one hand,it is an evolutionary design based on proven technology of the existing pressurized water reactor NPP;on the other hand,it incorporates advanced design features including a 177-fuel-assembly core loaded with CF3 fuel assemblies,active and passive safety systems,comprehensive severe accident prevention and mitigation measures,enhanced protection against external events,and improved emergency response capability.Extensive verification experiments and tests have been performed for critical innovative improvements on passive systems,the reactor core,and the main equipment.The design of HPR1000fulfills the international utility requirements for advanced light water reactors and the latest nuclear safety requirements,and addresses the safety issues relevant to the Fukushima accident.Along with its outstanding safety and economy,HPR1000 provides an excellent and practicable solution for both domestic and international nuclear power markets. 展开更多
关键词 被动安全系统 先进压水堆 中国核工业集团公司 压水堆核电站 设计哲学 燃料组件 轻水反应堆 进化设计
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Effectiveness of a 12-Week Program of Active and Passive Stretching in Improving Low Back and Neck Pain in Japanese Sedentary Men 被引量:1
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作者 Yuna Naraoka Mikiyuki Katagiri Takuji Shirasawa 《Health》 2017年第3期493-505,共13页
Purpose: Muscle stretching is frequently prescribed in physical therapy to manage lower back and neck pain. However, there is no clear evidence regarding the differences in effectiveness of active and passive stretchi... Purpose: Muscle stretching is frequently prescribed in physical therapy to manage lower back and neck pain. However, there is no clear evidence regarding the differences in effectiveness of active and passive stretching. Therefore, we aimed to evaluate the relative effectiveness of a 12-week program of active and passive stretching on selected physical and mental stress variables of sedentary men with lower back and neck pain. Methods: A cohort of 28 sedentary men, 30 - 49 years old, were divided into two intervention groups: the passive stretching group (PSG, n = 15) and the active stretching group (ASG, n = 13). A trainer assisted with static passive stretching, while participants in the ASG were provided with an instructional video. The following outcomes were measured at the start and end of the first and twelfth week of the stretching program: physical measures (visual analogue scale score of lower back and neck pain;finger-to-floor distance, gravimetric assessment of pelvic tilt, muscle hardness of the biceps femoris, and straight-leg raising) and mental stress measures (α-amylase and cortisol levels in saliva samples). Results: Although both active and passive stretching produced acute changes in lower back and neck pain, only passive stretching yielded long-term improvement in pain, finger-to-floor distance, pelvic tilt, hardness of biceps femoris muscle and cortisol levels (p Conclusion: Passive stretching is superior to active stretching in reducing pain, increasing muscle extensibility and correcting posture among a group of sedentary men with lower back and neck pain. 展开更多
关键词 active STRETCHING passive STRETCHING Lower Back PAIN Neck PAIN
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Association between head-and-neck cancers and active and passive cigarette smoking 被引量:1
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作者 Yukiomi Kushihashi Yoshiyuki Kadokura +5 位作者 Syuhei Takiguchi Yoshiyuki Kyo Yoshihiro Yamada Miki Shino Masato Kano Harumi Suzaki 《Health》 2012年第9期619-624,共6页
Although there have been many reports on the toxicity of tobacco smoke, fewer studies have reported the relationship between the smoke and carcinogenesis of head-and-neck cancers. It is assumed that direct stimulation... Although there have been many reports on the toxicity of tobacco smoke, fewer studies have reported the relationship between the smoke and carcinogenesis of head-and-neck cancers. It is assumed that direct stimulations due to tobacco smoke, such as chemical and mechanical stimulations, strongly influence the epithelium of the nasal cavity, paranasal sinuses, pharynx, and larynx. We investigated the influence of active and passive cigarette smoking on head-and-neck cancers. The subjects were 283 head-and-neck cancer patients examined at the otolaryngology department of Showa University Northern Yokohama Hospital in a 9-year and 2-month period from April 2001 to June 2010, in whom the presence or absence of active and passive cigarette smoking could be confirmed in detail. The active and passive smoking rates and the Brinkman index were retrospectively investigated according to the primary cancer site, gender, and histopathological classification. The active and passive smoking rates were high (about 90%) in patients with hypopharyngeal, laryngeal, and cervical esophageal cancers, and the Brinkman index was high in all. Squamous cell carcinoma (SCC) patients accounted for a high ratio of the head-and-neck cancer patients, and the active and passive smoking rates were significantly higher in SCC than in non-squamous cell carcinoma (non-SCC) patients (p < 0.0003). The active and passive smoking rates and the Brinkman index were high in patients with head-and-neck cancers in regions receiving strong direct stimulation from tobacco smoke, and the Brinkman index was also high in these patients, suggesting that carcinogenesis of head-and-neck cancers is strongly influenced by direct tobacco smoke stimulation. 展开更多
关键词 Head-and-Neck CANCERS SQUAMOUS Cell Carcinoma active SMOKING RATE passive SMOKING RATE Brinkman Index
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Validation and application of soil moisture active passive sea surface salinity observation over the Changjiang River Estuary 被引量:2
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作者 Qiong Wu Xiaochun Wang +1 位作者 Wenhao Liang Wenjun Zhang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2020年第4期1-8,共8页
Using sea surface salinity(SSS)observation from the soil moisture active passive(SMAP)mission,we analyzed the spatial distribution and seasonal variation of SSS around Changjiang River(Yangtze River)Estuary for the pe... Using sea surface salinity(SSS)observation from the soil moisture active passive(SMAP)mission,we analyzed the spatial distribution and seasonal variation of SSS around Changjiang River(Yangtze River)Estuary for the period of September 2015 to August 2018.First,we found that the SSS from SMAP is more accurate than soil moisture and ocean salinity(SMOS)mission observation when comparing with the in situ observations.Then,the SSS signature of the Changjiang River freshwater was analyzed using SMAP data and the river discharge data from the Datong hydrological station.The results show that the SSS around the Changjiang River Estuary is significantly lower than that of the open ocean,and shows significant seasonal variation.The minimum value of SSS appears in July and maximum SSS in December.The root mean square difference of daily SSS between SMAP observation and in situ observation is around 3 in both summer and winter,which is much lower than the annual range of SSS variation.In summer,the diffusion direction of the Changjiang River freshwater depicted by SSS from SMAP is consistent with the path of freshwater from in situ observation,suggesting that SMAP observation may be used in coastal seas in monitoring the diffusion and advection of freshwater discharge. 展开更多
关键词 soil moisture active passive mission in situ observation soil moisture and ocean salinity mission sea surface salinity Changjiang River(Yangtze River)Estuary freshwater plume
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Active and passive smoking with breast cancer risk for Chinese females: a systematic review and meta-analysis 被引量:12
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作者 Chuan Chen Yu-Bei Huang +9 位作者 Xue-Ou Liu Ying Gao Hong-Ji Dai Feng-Ju Song Wei-Qin Li Jing Wang Ye Yan Pei-Shan Wang Yao-Gang Wang Ke-Xin Chen 《Chinese Journal of Cancer》 SCIE CAS CSCD 2014年第6期306-316,共11页
Previous studies suggested that smoking and passive smoking could increase the risk of breast cancer, but the results were inconsistent, especially for Chinese females. Thus, we systematically searched cohort and case... Previous studies suggested that smoking and passive smoking could increase the risk of breast cancer, but the results were inconsistent, especially for Chinese females. Thus, we systematically searched cohort and case-control studies investigating the associations of active and passive smoking with breast cancer risk among Chinese females in four English databases(PubMed, Embase, ScienceDirect, and Wiley) and three Chinese databases(CNKI, WanFang, and VIP). Fifty-one articles(3 cohort studies and 48 casecontrol studies) covering 17 provinces of China were finally included in this systematic review. Among Chinese females, there was significant association between passive smoking and this risk of breast cancer [odds ratio(OR): 1.62; 95% confidence interval(CI): 1.39–1.85; I2 = 75.8%, P < 0.001; n = 26] but no significant association between active smoking and the risk of breast cancer(OR: 1.04; 95% CI: 0.89–1.20; I2 = 13.9%, P = 0.248; n = 31). The OR of exposure to husband's smoking and to smoke in the workplace was 1.27(95% CI: 1.07–1.50) and 1.66(95% CI: 1.07–2.59), respectively. The OR of light and heavy passive smoking was 1.11 and 1.41, respectively, for women exposed to their husband's smoke(< 20 and ≥ 20 cigarettes per day), and 1.07 and 1.87, respectively, for those exposed to smoke in the workplace(< 300 and ≥ 300 min of exposure per day). These results imply that passive smoking is associated with an increased risk of breast cancer, and the risk seems to increase as the level of passive exposure to smoke increases among Chinese females. Women with passive exposure to smoke in the workplace have a higher risk of breast cancer than those exposed to their husband's smoking. 展开更多
关键词 被动吸烟 乳腺癌 风险 中国 女性 系统 工作场所 队列研究
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Effectiveness of a Passive-active Vibration Isolation System with Actuator Constraints 被引量:5
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作者 SUN Lingling SUN Wei +1 位作者 SONG Kongjie HANSEN Colin H 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2014年第3期567-574,共8页
In the prediction of active vibration isolation performance, control force requirements were ignored in previous work. This may limit the realization of theoretically predicted isolation performance if control force o... In the prediction of active vibration isolation performance, control force requirements were ignored in previous work. This may limit the realization of theoretically predicted isolation performance if control force of large magnitude cannot be supplied by actuators.The behavior of a feed-forward active isolation system subjected to actuator output constraints is investigated. Distributed parameter models are developed to analyze the system response, and to produce a transfer matrix for the design of an integrated passive-active isolation system. Cost functions comprising a combination of the vibration transmission energy and the sum of the squared control forces are proposed. The example system considered is a rigid body connected to a simply supported plate via two passive-active isolation mounts. Vertical and transverse forces as well as a rotational moment are applied at the rigid body, and resonances excited in elastic mounts and the supporting plate are analyzed. The overall isolation performance is evaluated by numerical simulation. The simulation results are then compared with those obtained using unconstrained control strategies. In addition, the effects of waves in elastic mounts are analyzed. It is shown that the control strategies which rely on tmconstrained actuator outputs may give substantial power transmission reductions over a wide frequency range, but also require large control force amplitudes to control excited vibration modes of the system. Expected power transmission reductions for modified control strategies that incorporate constrained actuator outputs are considerably less than typical reductions with unconstrained actuator outputs. In the frequency range in which rigid body modes are present, the control strategies can only achieve 5-10 dB power transmission reduction, when control forces are constrained to be the same order of the magnitude as the primary vertical force. The resonances of the elastic mounts result in a notable increase of power transmission in high frequency range and cannot be attenuated by active control. The investigation provides a guideline for design and evaluation of active vibration isolation systems. 展开更多
关键词 passive-active isolation transfer matrix control effort constraint feedforward control
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Helping Students Make a Shift from Passive Learning to Active Learning
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作者 李艳 《海外英语》 2015年第10期250-251,共2页
To cultivate the students' active learning strategy becomes the new challenge for English teaching reforms in China.The essay is to move from theory about motivation and beliefs that might underlie student resista... To cultivate the students' active learning strategy becomes the new challenge for English teaching reforms in China.The essay is to move from theory about motivation and beliefs that might underlie student resistance to active learning to practical suggestions that might counter that resistance. 展开更多
关键词 active LEARNING passive LEARNING CONSTRUCTIVIST activities
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An active-passive beam current transformer 被引量:1
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作者 ZHOU Wei SUN Baogen LU Ping WANG Xiaohui WANG Yong ZHANG Haiyan 《Nuclear Science and Techniques》 SCIE CAS CSCD 2008年第2期70-73,共4页
In this article,a new type current transformer was developed using an active-passive circuit to improve low frequency response of the system without impairing high frequency response.The active-passive current transfo... In this article,a new type current transformer was developed using an active-passive circuit to improve low frequency response of the system without impairing high frequency response.The active-passive current transformer with In-flange was fabricated.Theoretical analysis,numerical simulations and experimental results are given. 展开更多
关键词 电流 变压器 电路 频率反应
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Effective transport of passive particles induced by chiral-active particles in microchannel
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作者 华昀峰 何林李 章林溪 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第8期108-113,共6页
Transport of passive particles induced by chiral-active particles in microchannel is investigated by using the overdamped Langevin dynamics simulation in a two-dimensional model system. Due to the chirality of active ... Transport of passive particles induced by chiral-active particles in microchannel is investigated by using the overdamped Langevin dynamics simulation in a two-dimensional model system. Due to the chirality of active particles and special structure of microchannel, effective ratchet transport of passive particles is achieved. Effective transport of passive particles depends on the width of microchannel(d), the density(ρ), and the angular velocity(ω) of chiral-active particles.There exist optimal parameters for d and ω at which the transport efficiency for passive particles takes its maximal value.This investigation can help us understand the necessity of active motion for living systems to maintain a number of vital processes such as materials transport inside cells and the foraging dynamics of mobile organisms. 展开更多
关键词 TRANSPORT active particle passive particle overdamped Langevin dynamics simulation MICROCHANNEL
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Encouraging Active Viewing, Rather Than Passive Watching in the Audio-visual English Class 被引量:1
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作者 Yuwei Zeng 《Sino-US English Teaching》 2005年第2期33-37,共5页
关键词 英语教学 电影片段 主动语态 学习能力 教学方法
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Roughness correction method for salinity remote sensing using combined active/passive observations
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作者 Wentao Ma Guihong Liu +1 位作者 Yang Yu Yanlei Du 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2021年第11期189-195,共7页
Roughness-induced emission from ocean surfaces is one of the main issues that affects the retrieval accuracy of sea surface salinity remote sensing.In previous studies,the correction of roughness effect mainly depende... Roughness-induced emission from ocean surfaces is one of the main issues that affects the retrieval accuracy of sea surface salinity remote sensing.In previous studies,the correction of roughness effect mainly depended on wind speeds retrieved from scatterometers or those provided by other means,which necessitates a high requirement for accuracy and synchronicity of wind-speed measurements.The aim of this study is to develop a novel roughness correction model of ocean emissivity for the salinity retrieval application.The combined active/passive observations of normalized radar cross-sections(NRCSs)and emissivities from ocean surfaces given by the L-band Aquarius/SAC-D mission,and the auxiliary wind directions collocated from the National Centers for Environmental Prediction(NCEP)dataset are used for model development.The model is validated against the observations and the Aquarius standard algorithms of roughness-induced emissivity correction.Comparisons between model computations and measurements indicate that the model has better accuracy in computing wind-induced brightness temperature in the upwind/downwind directions or for the surfaces with smaller NRCSs,which can be better than 0.3 K.However,for crosswind directions and larger NRCSs,the model accuracy is relatively low.A model using HH-polarized NRCSs yields better accuracy than that using VV-polarized ones.For a fair comparison to the Aquarius standard algorithms using wind speeds retrieved from multi-source data,the maximum likelihood estimation is employed to produce results combining our model calculations and those using other sources.Numerical simulations show that combined results basically have higher accuracy than the standard algorithms. 展开更多
关键词 salinity remote sensing roughness correction Aquarius satellite active/passive
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Constraint dependence of average potential energy of a passive particle in an active bath
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作者 叶思敏 刘鹏 +3 位作者 魏子轩 叶方富 杨明成 陈科 《Chinese Physics B》 SCIE EI CAS CSCD 2020年第5期32-36,共5页
We quantify the mean potential energy of a passive colloidal particle harmonically confined in a bacterial solution using optical traps.We find that the average potential energy of the passive particle depends on the ... We quantify the mean potential energy of a passive colloidal particle harmonically confined in a bacterial solution using optical traps.We find that the average potential energy of the passive particle depends on the trap stiffness,in contrast to the equilibrium case where energy partition is independent of the external constraints.The constraint dependence of the mean potential energy originates from the fact that the persistent collisions between the passive particle and the active bacteria are influenced by the particle relaxation dynamics.Our experimental results are consistent with the Brownian dynamics simulations,and confirm the recent theoretical prediction. 展开更多
关键词 constraint dependence average potential energy active bath passive tracer optical trap
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