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1.
As the ion density at a solid–liquid interface changes, the interfacial tension varies accordingly, which can lead to a large energy density output, particularly when amplified by the high specific surface area of a nanoporous material. This concept is validated by the results of a controlled-temperature infiltration experiment on a hydrophobic zeolite immersed in a saturated aqueous solution of sodium acetate. As the temperature changes, the sodium acetate concentration varies significantly, which in turn causes a variation in infiltration pressure. Since the infiltration and defiltration are reversible, under the working pressure, this system exhibits a volume memory characteristic, with a non-monotonic temperature–volume relationship.  相似文献   

2.
气温与气温变化对心理健康的威胁和影响引起越来越多研究者的关注。气温及气温变化对情绪体验、抑郁症等情感障碍、精神分裂症、阿尔茨海默等脑器质性精神障碍、物质滥用与依赖、自杀意念与行为等心理健康指标具有直接或间接的影响。气象情绪效应、棕色脂肪组织理论和血清素理论从生理角度解释气温影响心理健康的机制, 健康保持行为理论则从行为角度解释气温与心理健康的关系。儿童青少年、老年人、工人是高温与高温压力的易感人群。气温变化对心理健康的影响还存在性别、年龄、社会经济地位等方面的差异。未来研究应进一步区分不同的气温指标, 增加对低温与心理健康关系的关注, 控制其它因素对气温与心理健康关系的干扰, 并揭示群体间差异。  相似文献   

3.
The purpose of this study was to compare the effects of restricted environmental stimulation using a flotation tank (Flotation REST) to the effects of a normal sensory environment on relaxation. All of the subjects were first introduced to a simple relaxation program to be used during the experimental sessions. The program consisted of guided point-to-point relaxation, breathing techniques, and visual imagery techniques. Subjects were then pre-tested on measurements of electromyogram (EMG), galvanic skin response (GSR), peripheral skin temperature, and systolic and diastolic blood pressure. The experimental group experienced ten 45-minute sessions practicing the relaxation program in a Flotation REST environment. The control subjects practiced the same relaxation program in a similar body position for 45 minutes in a normal sensory environment. All subjects answered a five-question Subjective Relaxation Questionnaire on trials five through ten and were then post-tested on EMG, GSR, skin temperature, and blood pressure. The results indicated significant differences between groups from pre-test to post-test on systolic and diastolic blood pressure; the experimental group showed greater reductions. Significant differences also were observed on three of five questions on the Subjective Relaxation Questionnaire; the experimental group reported greater subjective relaxation and trends in a similar direction on the remaining two questions. The results of this study indicate that flotation REST enhances point-to-point relaxation, breathing techniques, and visual imagery techniques and, when combined with these techniques, can be an effective means of teaching normal subjects to lower systolic and diastolic pressure and heighten their subjective perception of relaxation.  相似文献   

4.
The present study examines the effects of six weather parameters (temperature, wind power, sunlight, precipitation, air pressure, and photoperiod) on mood (positive affect, negative affect, and tiredness). Data were gathered from an online diary study (N = 1,233), linked to weather station data, and analyzed by means of multilevel analysis. Multivariate and univariate analyses enabled distinction between unique and shared effects. The results revealed main effects of temperature, wind power, and sunlight on negative affect. Sunlight had a main effect on tiredness and mediated the effects of precipitation and air pressure on tiredness. In terms of explained variance, however, the average effect of weather on mood was only small, though significant random variation was found across individuals, especially regarding the effect of photoperiod. However, these individual differences in weather sensitivity could not be explained by the Five Factor Model personality traits, gender, or age.  相似文献   

5.
Eight adult women volunteers viewed the same erotic film in two different sessions. Their resulting genital responses were recorded simultaneously by three different measures: vaginal pressure pulse, vaginal blood volume, and labial temperature change. During the erotic stimulation, the vaginal pressure pulse and labial responses always increased, and the vaginal blood volume response increased on all but two occasions. Although there was considerable intersubject variability in each genital measure, all three measures were found to have some intrasubject consistency over sessions with respect to either their response amplitudes or patterns, with labial temperature being the most consistent on both parameters. The relationship between the response patterns of the three measures during the film was also relatively consistent across sessions, as was the correspondence between subjective ratings of arousal and both vaginal pressure pulse and labial responses but not vaginal blood volume response. To overcome the problem of considerable intrasubject variability of response amplitudes, it was suggested that the inclusion in the data analysis of several parameters of response patterns, which were relatively stable over sessions, might facilitate the evaluation of a treatment.  相似文献   

6.
The purpose of the present study was to evaluate the efficiency of temperature variations as a measure against drivers' drowsiness. A system for regulation of the air temperature in the cab was installed in two trucks. Irregular temperature reductions of about 8 degrees C were introduced. The periods between the temperature reductions varied among 5, 6, 7, and 8 min. The periods for the temperature reductions varied between 2, 4, 6, and 8 min. The system was tested with 6 drivers on 54 trips. The system was applied for periods varying between 30 to 300 min. Changes in wakefulness were analysed using subjective ratings by the lorry drivers. The application of the system significantly improved subjectively rated wakefulness. The wakefulness was rated with a questionnaire completed after 10 min. use of a cooling system and at the end of its use. Analysis showed individual differences in the usefulness of the system: 3 of the 6 truck drivers reported positive reactions to the use of the temperature cooling system.  相似文献   

7.
不同干预方法对应激时身心状态的影响   总被引:1,自引:0,他引:1  
选取72名被试,随机分配到对照组、腹式呼吸组和忽视调节组中。采用重复一个因素的三因素混合实验设计,测量被试基线期、干预期、应激期、恢复期的指温、收缩压和应激前后的主观感受,探讨不同干预方法对应激的干预效果。结果表明,腹式呼吸能够降低男生的心血管反应,忽视调节能够降低女生的主观体验,同时也表明,个体生理反应升高并不必然伴随主观体验的升高。  相似文献   

8.
盖雯婷  周楚 《心理科学》2013,36(6):1296-1300
主要探讨推理中信息相关因素对分析系统与启发式系统的影响。通过两个实验考察信息的充分性和情绪性对突发事件情境下推理的影响。实验1任务无时间压力,结果发现:信息充分性对推理的影响显著,表现为信息越充分,被试推理的逻辑指数越高,更多使用了分析系统;且信息充分时,接受积极信息的被试的信念指数显著增高。实验2任务有时间压力,结果发现:信息的情绪性对推理的影响显著,表现为接受积极信息的被试推理的逻辑指数显著大于接受消极信息组,更多使用了分析系统。两个实验结果表明,信息的充分性主要通过分析系统对推理产生影响,而信息的情绪性可通过双系统影响推理过程,即积极信息在推理时间充裕时促进启发式系统,但在有时间压力下促进分析系统。  相似文献   

9.
Germanium has been processed by high-pressure torsion (HPT) under a nominal pressure of 24 GPa at room temperature and cryogenic temperature. The samples processed at room temperature were composed of a diamond-cubic Ge-I phase and a metastable tetragonal Ge-III phase. The formation of Ge-III was significantly suppressed and Ge-I and an amorphous phase, in addition to a small amount of body-centred-cubic Ge-IV, appeared in the case of cryogenic HPT processing at 100 K. The Ge-IV phase gradually disappeared at room temperature. These results indicated that shear strain and thermal energy are important for promoting the formation of Ge-III.  相似文献   

10.
We examined the basic question of whether pressure is stressful. We proposed that when examining the role of stress or pressure in cognitive performance, it is important to consider the type of pressure, the stress response, and the aspect of cognition assessed. In Experiment 1, outcome pressure was not experienced as stressful but did lead to impaired performance on a rule-based (RB) category-learning task, but not on a more procedural information-integration (II) task. In Experiment 2, the addition of monitoring pressure resulted in a modest stress response to combined pressure and impairment on both tasks. Across experiments, higher stress appraisals were associated with decreased performance on the RB, but not on the II, task. In turn, higher stress reactivity (i.e., heart rate) was associated with enhanced performance on the II, but not on the RB, task. This work represents an initial step toward integrating the stress cognition and pressure cognition literatures and suggests that integrating these fields may require consideration of the type of pressure, the stress response, and the cognitive system mediating performance.  相似文献   

11.
High-pressure X-ray diffraction studies on gadolinium sesquioxide (Gd2O3) have been carried out up to a pressure of ~25 GPa in a diamond-anvil cell at room temperature. Gadolinium oxide, which has a cubic or bixbyite structure under ambient conditions, undergoes an irreversible structural phase at around 12 GPa. The high-pressure phase has been identified as a hexagonal La2O3-type structure. The bulk modulus and its pressure derivative of this phase have been calculated.  相似文献   

12.
The effects of unilateral forced nostril breathing on the intraocular pressures of right and left eyes was studied in 24 male and 26 female right-handed adults. In men, the forced breathing through both the right and left nostrils significantly decreased the intraocular pressures of both right and left eyes. For women, the forced breathing through right nostril did not affect the intraocular pressures of right and left eyes, and the forced breathing through left nostril also had no effect on the intraocular pressure of right eye, although it decreased the intraocular pressure of left eye significantly. These results show that unilateral forced nostril breathing decreases intraocular pressure especially in men, perhaps increasing sympathetic nervous system activity.  相似文献   

13.
We examined several models representing the relations among parenting practices, family structure, peer pressure, and drug use in a sample of 443 seventh graders. The setting was an urban school system serving a high percentage of African American students from low-income families. Analyses using structural equation modeling supported a mediation model in which both peer pressure and parenting practices had direct effects on drug use, with peer pressure mediating the influence of parenting. Within this model, family structure had a significant direct effect on parenting, however, contrary to hypotheses, children from two-parent families were more likely to report that they received adequate parenting than were children from single-parent extended families. Several gender differences were also found. Peer pressure was more highly related to drug use for girls than for boys, and the relation between parenting and peer pressure was stronger for boys. Examination of a model that included moderator effects revealed that the relation between peer pressure and drug use increased as a function of poor parenting. Results of our study underscore the importance of drug prevention efforts focused on parenting practices.  相似文献   

14.
Human society has evolved to allow third parties—the court system, parents or other societal arbitrators—to punish norm violators and compensate victims. Few studies explore the effect of stress or time pressure on a third‐party judge. Under time pressure, people will likely show a more instinctual reaction or judgment style. We investigated third‐party punishment and compensation within the context of unfairly shared losses and gains in a dictator game under time pressure. Our results show that under no time pressure, participants were inclined to punish dictators who unfairly split windfall gains; however, participants chose to compensate victims more than punish the norm‐violating dictators in the context of unfairly shared losses. With added time pressure, third‐parties were disposed to inflict punishment upon the dictator in both the gain and loss contexts—punishment became the action of choice. Our results shed light on the way observed behavior and stress affect social cognition and decision making in the context of altruistic social interventions and the enforcement of social norms.  相似文献   

15.
A radiotelemetry system for continuous monitoring of the temperature and/or location of small animals is described. All the functions of system control are carried out by an on-line microcomputer (TRS-80 Model III), resulting in a versatile system capable of alternating recording the temperature/location of multiple subjects with other behavioral or physiological events, such as activity level. We describe the use of this system in monitoring body temperature in hamsters and in recording the incubation pattern of breeding ring doves.  相似文献   

16.
The pressure dependence of the electrical resistivity of three different samples of cassiterite, namely natural cassiterite SnO2, synthetic nanocrystalline SnO2 (with crystallite size 46?nm) and nanocrystalline Co-doped SnO2 (with crystallite size 32?nm), has been measured up to 7?GPa at room temperature. The resistivity of natural cassiterite SnO2 decreases from 2.5?×?104?Ωm at normal pressure and temperature to 1.7?×?104?Ωm at 7.0?GPa. The nanocrystalline SnO2 has a high resistivity 6.0?×?105?Ωm at normal pressure and temperature and decreases with pressure reaching a value of 2.98?×?105?Ωm at 7?GPa. The activation energy of the electrical conduction of the studied samples were found to be 0.32?eV for the natural SnO2, 0.40?eV for the nanocrystalline SnO2 sample and 0.28?eV for the nanocrystalline Co-doped SnO2. Measurements of the pressure dependence of the electrical resistivity of the Co-doped SnO2 showed a decrease from 3.60?×?105 to 5.4?×?104?Ωm at 7.0?GPa. We did not observe any pressure-induced phase transition in SnO2 up to 7?GPa. This study of the high-pressure phase stability of cassiterite corroborates the experimental findings of SnO2 nanoinclusions in diamonds.  相似文献   

17.
Presently available procedures for measuring blood pressure are not completely satisfactory for Es wishing to investigate the operant conditioning of cardiovascular activity. A system is described for measuring a correlate of the blood pressure information obtained with conventional sphygmomanometric systems. The procedure involves the measurement of speed of propagation through the arterial system of the pressure pulse from the heart’s contraction. This speed, the pulse wave velocity, is closely related to cuff-derived blood pressure. Many of the problems present with current sphygmomanometric systems are absent with this apparatus and procedure. The apparatus can be assembled from common instruments or constructed from integrated circuits. Data collected with the apparatus confirm earlier studies which indicate that pulse wave velocity is correlated with sphygmomanometrically measured blood pressure and is a valuable cardiovascular response measure.  相似文献   

18.
The transswitching paradigm was used in the present study to investigate the effects of tonic (long duration) environmental stimuli paired with opposing unconditional stimuli on human blood pressure. Sixty volunteers participated for two sessions, one week apart. Subjects were presented with a pseudorandom sequence of four trials of red lights (five minutes each) and four trials of blue lights (five minutes each) within each session. All subjects received the cold pressor test during the red lights. During the blue lights, half the subjects received warm water and the other half received a neutral temperature water. Subjects received the presentations of the water in one of three methods: as determined by the experimenter, preceded by a warning signal, or self-administered. The results indicated that conditional and unconditional responses during the red lights were progressive increases in blood pressure. During the blue lights associated with warm water, conditional and unconditional responses were often progressive decreases in blood pressure. The method of administration of the water affected the magnitude of the unconditional responses. Evidence for phasic stimulus control was not as unequivocal as tonic stimulus control. The present results indicated that it is possible to modify blood pressure in two directions (increases and decreases) when two high contrast, opposing unconditional stimuli are presented.  相似文献   

19.
ABSTRACT

Background and Objectives: While the potentially negative effects of pressure on skilled performance have been well studied in laboratory-based research, theoretically driven questions based on real-world performance data are lacking.

Design: We aimed to test the predictions of the newly developed Attentional Control Theory: Sport (ACTS), using archived play-by-play data from the past seven seasons of the National Football League (American Football).

Methods: An additive scoring system was developed to characterize the degree of pressure on 212,356 individual offensive plays and a Bayesian regression model was used to test the relationship between performance, pressure and preceding negative outcomes, as outlined in ACTS.

Results: There was found to be a clear increase in the incidence of failures on high pressure plays (odds ratio?=?1.20), and on plays immediately following a previous play failure (odds ratio?=?1.09). Additionally, a combined interactive effect of previous failure and pressure indicated that the feedback effect of negative outcomes was greater when pressure was already high (odds ratio?=?1.10), in line with the predictions of ACTS.

Conclusions: These findings reveal the importance of exploring momentary changes in pressure in real-world sport settings, and the role of failure feedback in influencing the pressure-performance relationship.  相似文献   

20.
A tether system has been developed for continuous monitoring of blood pressure in the micropig. The micropig is a suitable model for blood-pressure research because of the similarity of its cardiovascular system to that of humans and because of its sensitivity to high sodium intake. The system consists of a metal boom, attached via a universal joint to a wall 6 ft above floor level, that extends horizontally to the center of the enclosure. A fluid and electronic swivel affixed to the boom is connected to a flexible, hollow, metal tether that descends to a vest worn by the micropig. The vest contains a pressure transducer to which an indwelling arterial catheter is connected via a stopcock. The transducer cable and an infusion line ascend through the interior of the tether to the swivel. The system remains in equilibrium through a system of pulleys and counterweights. Continuous, 24-h recording shows a diurnal variation characterized by higher heart rate but lower blood pressure during the day than at night. The system has been found to be effective for continuous studies over intervals of a month or more.  相似文献   

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