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1.
In the beach well intake system, heat is transferred from soil to fluid when seawater is filtered through the aquifer, providing higher temperature source water to the seawater source heat pump (SWHP) system in winter. A 3-D coupled seepage and heat transfer model for studying beach well intake system is established by adopting the computer code FLUENT. Numerical results of this model are compared with the experimental results under the same conditions. Based on the experiment-verified coupled model, numerical simulation of the supply water temperature is studied over a heating season. Results show that the minimum temperature of supply water is 275.2 K when this intake system continuously provides seawater with flow rate of 35 m3/h to SWHP. Results also indicate that the supply water temperature is higher than seawater, and that the minimum temperature of supply water lags behind seawater, ensuring effective and reliable operation of SWHP.  相似文献   

2.
Consumption of food pellets was examined in four water-deprived rats during 1-h sessions in which water was presented once every 30, 60, or 120 sec independently of the rats’ behavior according to three fixed-time (FT) schedules. Correlated with each FT condition was a continuous reinforcement (CRF) control condition in which the rats received, at the start of the session, the number of dipper presentations that were programmed to occur during the corresponding FT condition. During both the FT and CRF conditions, pellets per dipper presentation decreased and food intake rate increased with rate of water presentation, and there was a direct linear relation between log food intake and log water intake. For each of these three measures there was less eating under the FT condition than under the CRF condition, but the difference between the FT and CRF functions decreased at shorter FT values. These data are discussed in terms of the effects of amount of water on food consumption and the principle of temporal summation.  相似文献   

3.
In two experiments, the hypothesis that frustration mediates the production of schedule-induced polydipsia was tested. In Experiment I, a group in which reward was reduced from 6 to 2 pellets of food in an operant chamber was found to increase water intake compared to a group maintained at 2 pellets reward. In Experiment II, rats trained to approach food on a partial reinforcement schedule in a runway subsequently showed lower levels of water intake in the operant test for polydipsia than rats given continuous reinforcement during runway training. The results are interpreted as supporting a frustration hypothesis of schedule-induced polydipsia and are discussed within the context of persistence theory.  相似文献   

4.
以江西数个火电厂取水管道工程为例,详细介绍了取水管道敷设时容易遇见的问题,针对存在的问题给出了有效的处理方法,为其他取水管道工程的设计提供了参考。  相似文献   

5.
Blue Baby Syndrome or Methemoglobinemia is caused by decreased ability of blood to carry oxygen, resulting in oxygen deficiency in different body parts. Infants are more susceptible than adults. The disease can be caused by intake of water and vegetables high in nitrate, exposure to chemicals containing nitrate, or can even be hereditary. Groundwater gets contaminated by leaching of nitrate generated from fertilizer used in agricultural lands and waste dumps in rural and urban areas. Prevention of water contamination, abstention from drinking contaminated water and controlling nitrate levels in drinking water by water treatment are effective preventive measures against nitrate poisoning.  相似文献   

6.
氟是人体重要的微量元素,对维持骨骼和牙齿健康有重要作用.适量的氟摄入对人体健康有利,但过多的摄入氟会导致氟中毒.长期饮用浓度高于1 mg/L的水将会引起氟斑牙病、氟骨病等.我国是一个典型的地方性氟中毒地区之一.所以研究高效、经济的饮用水中微量氟离子的去除方法具有具有重要的科学价值和社会意义.本文综合各类氟离子去除方法,提出应用钙盐沉淀结合活性炭法来去除饮用水中的微量氟离子,并通过实验研究了其可行性,从而得出一种有效,经济的氟离子去除方法.  相似文献   

7.
It was demonstrated that an odor presented to rats in a distinctive environment can interfere with toxicosis-based conditioning to the environmental cues. Rats poisoned when they drank unflavored water in a black compartment odorized with oil of eucalyptus exhibited no suppression of water intake when they were subsequently tested in the same compartment minus the odor. In contrast, rats poisoned in the same compartment minus the odor later exhibited reduced water consumption in that environment. Oil of eucalyptus proved to be as effective an overshadowing stimulus as a taste cue (a 1.5% NaCl solution).  相似文献   

8.
Kenya experienced a severe drought and temporary food shortage during a study on mild malnutrition. Effects of the temporary food shortage on energy intake, weight, and behaviors were evaluated in schoolchildren and in toddlers and their mothers. Schoolchildren were seriously affected, showing significant declines in their energy intake, age-corrected weight, activity on the playground, and classroom attention. Toddlers appear to have been somewhat protected since their energy intake, weight, and play and language behaviors were stable. Maternal caregiving of toddlers declined for the group as a whole, but individually those mothers who maintained family food levels delegated responsibility for toddlers to other caregivers. While the food shortage affected poorer families more than those of higher SES, declines in the behaviors of schoolchildren occurred regardless of SES and previous level of nutrition, suggesting that food shortages can have behavioral consequences for schoolchildren in all communities.  相似文献   

9.
The present study aimed to evaluate the anti-diabetic property of peanut shell polyphenol extracts (PSPEs). Diabetic rats were oral-administrated with PSPE at doses of 50, 100, and 200 mg/kg body weight (BW) per day for 28 consecutive days, with metformin (Met) as a positive control. The results showed that, similar to the Met treatment, administration of PSPE caused significant decreases in food intake, water intake, fasting blood glucose, total cholesterol, triglyceride, low-density lipoprotein cholesterol, and methane dicarboxylic aldehyde in serum, and significant increases in BW, insulin level, high-density lipoprotein cholesterol, superoxide dismutase, glutathione, and liver glycogen. Further, glucose tolerance was markedly improved in the PSPE-treated diabetic groups. Histopathological results showed that PSPE improved cellular structural and pathological changes in liver, kidney, and pancreatic islets. Collectively, the results indicated that the hypoglycemic effects of PSPE on high-fat diet/streptozotocin (HFD/STZ)- induced diabetes are comparable to Met, though their exact mechanism actions are still under investigation. Therefore, the current study suggests that PSPE could be a potential health-care food supplement in the management of diabetes.  相似文献   

10.
从泵站规划、水泵、电动机及辅助设备、进、出水建筑物、变电所及输电线路等方面对陕西省东雷一期抽黄、宝鸡峡、交口等8处大型泵站工程分析,提出陕西省大型泵站工程现状存在的主要问题,为陕西省大型泵站工程更新改造规划提供必要的改造思路。  相似文献   

11.
Hong Kong has introduced a senior intake admission scheme which is similar to the US model of credit transfer from community college programmes to university bachelor programmes. The study aimed to assess the outcomes, in terms of generic capabilities, of introducing a senior intake articulation scheme to a bachelor of nursing curriculum in Hong Kong. One hundred and seventy-four nursing students completed and returned the Student Engagement Questionnaire. The senior intake students reported significantly higher scores in creative thinking, active learning, teaching for understanding, feedback to assist learning, and relationship between teachers and students than the mainstream students. Self-managed learning and relationship with other students were positively and significantly related to academic performance. The senior intake students appeared to adjust well in university education. Greater effort should be made to nurture their relationship with other students and a review of the denseness of the mainstream curriculum is warranted.  相似文献   

12.
为了提高学生对"提高反刍动物粗饲料采食量重要性"的认识,在进行该论点的讲述过程中,首先采用传统的说教式(灌输式)教学方法对上述论点进行了定性论述,对学生产生第1次听觉刺激;在此基础上,以肉羊为研究对象,构建反映平均日增重与饲料采食量关系数学模型,进一步揭示提高反刍动物粗饲料采食量对生产性能影响的量化关系,通过这种定量描述对学生产生第2次听觉刺激;最后结合相关图表的配套应用,在对听觉系统产生刺激的基础上,同时刺激视觉系统。通过上述综合刺激,使学生加深了对提高反刍动物粗饲料采食量重要性的理解,取得良好的教学效果。  相似文献   

13.
农村职业技术教育发展现状及出路   总被引:3,自引:0,他引:3  
由于各方面条件制约,我国农村职业技术教育发展陷入困境.为解决发展出路问题,地方政府要认真落实农职教政策法规;职业学校应加强农村劳动力的创业教育和培训,促进农村劳动力转移;政府提供中介服务、城乡职校联合办学,以出口拉动入口,增加农村职校的吸引力;基地建设与"双师型"师资培养并重,加强农村职教师资队伍建设.  相似文献   

14.
Following ingestion of either water (Experiment 1) or saccharin (Experiment 2), experimental groups of rats were poisoned with lithium chloride and acquired an aversion to the ingested fluid. This aversion gradually extinguished and, in both experiments, was not reacquired when fluid intake was again followed by poisoning. These results are in marked contrast to usual findings of very rapid relearning following extinction with conditioning preparations other than taste-aversion learning.  相似文献   

15.
16.
Two related studies addressed college students' persistence and progress in psychotherapy. In Study 1, using emotional health variables assessed at intake, students who persisted in counseling and demonstrated clinical improvement were compared with those who either did not return for their first session or who did return but stopped before improvement. Findings showed that those counseling completers, compared with the other two groups, reported at intake significantly higher levels of confidence that therapy will help, degree of well-being, and levels of life functioning. Study 2, focusing on students who received at least eight counseling sessions, found improvement on variables reflecting distress and life functioning, with students who rated themselves highly distressed at intake reporting the most benefit. The findings suggest approaches to improve realistic expectations for and engagement in counseling.  相似文献   

17.
EGSB反应器处理模拟啤酒废水,启动实验表明:接种消化污泥的反应器运行2个月能够启动成功。为了尽快形成活性高、沉降性能好的颗粒污泥,EGSB的启动宜采用先低后高的进水浓度,并逐渐提高反应器内的上升流速和有机负荷。  相似文献   

18.
Four experiments examined whether or not spontaneous recovery could occur after extinction in the conditioned taste-aversion paradigm. After three extinction trials, spontaneous recovery was obtained over an 18-day retention interval (Experiments 1, 2, and 3). The effect was not due to changes in the unconditioned preference for saccharin over the retention interval (Experiment 2) or to an increase in a nonextinguished aversion over time, as indicated by tests with both the original, nonextinguished aversion (Experiment 1) and with a weaker one (Experiment 3). Spontaneous recovery was not obtained when extinction was overtrained (eight trials) and a 49-day retention interval was used (Experiment 4). However, saccharin intake at asymptote reached the level of baseline water intake, and not the highly preferred level shown by never-conditioned controls. Results of all four experiments suggest that extinction does not return an averted taste to the status of an unconditioned one.  相似文献   

19.
Based on the desilting research of one scheduling project in the southwest of China, the method of setting grid desilting gallcry before the desilting tunnel is put forward to expand the scope of the scouring funnel before the dam and solve the problem of sediment deposition at the power station water intake. The experimental results show that, in the design of a grid desilting gallery, the width of the grid gallery should not be smaller than that of the desilting bottom in-take, the size of the grid orifice should be in the range of 1.5 m-2.0 m along the flow direction, and the grid spacing should be 3-5 times the size of the grid orifice. The discharging ability of the desilting bottom intake will decrease after the grid desilting gallery is added. The average of the decrease rates is about 5%-10%. The scouring funnel draws in the longitudinal direction before the dam obviously after the construction of the grid desilting gallery.  相似文献   

20.
Regional drought analysis provides useful information for sustainable water resources management. In this paper, a standardized precipitation index (SPI) at multiple time scales was used to investigate the spatial patterns and trends of drought in the Han River Basin, one of the largest tributaries of Yangtze River, China. It was found that, in terms of drought severity, the upper basin of the Han River is the least, while the growing trend is the most conspicuous; a less conspicuous growing trend can be observed in the middle basin; and there is an insignificant decreasing trend in the lower basin. Meanwhile, the impact of drought on the Middle Route of the South-to-North Water Transfer Project was investigated, and it is suggested that water intake must be reduced in times of drought, particularly when successive or simultaneous droughts in the upper and middle basins of the Han River Basin occur. The results can provide substantial information for future water allocation schemes of the South-to-North Water Transfer Project.  相似文献   

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