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1.
城市不同绿地垂直热力效应比较   总被引:14,自引:2,他引:14  
城市绿地改变了城市地表面的辐射状况以及近地面大气的辐射状况,使绿地附近大气热力特性发生变化,产生绿地与非绿地之间的温度差异,形成局地小气候环流。不同类型城市绿地热力效应不同,产生的局地环流强度也存在差异,对城市生态环境的改善效果也各不相同。研究不同类型城市绿地热力特征,揭示不同类型城市绿地的小气候效应差异,将有助于城市园林绿地规划与管理,有助于改善城市生态环境。试验者在太原市区选择了3种不同的城市绿地——城市森林、灌丛、草坪。在氢气球上悬挂测绳,利用测绳上系有的温湿度记录仪对不同绿地周边温度时、空变化进行测试。通过对所得试验数据分析,得出昼间不同绿地热力变化规律以及14:00—15:30不同绿地空间温度场分布特点。结果表明:不同绿地周边都存在明显的热力效应;森林周边热力效应较其它绿地更明显,14:00—15:30冷源效应在1.5、3m高度可影响到距林缘14m处,17:00—18:30森林有明显的热源效应;灌丛和草坪的冷热源效应较森林明显减弱,影响的高度和距离也明显减小;14.00—15:30,不同绿地周边气温垂直结构中都存在一个高温中心和低温中心,说明绿地与非绿地之间应该存在着局地小气候环流。这些研究结果为进一步研究不同城市绿地小气候环流提供了依据。  相似文献   

2.
Analysis of the catechol-O-methyltransferase (COMT) enzyme in human RBC lysates from 15 samples exhibiting inherited variations in level of activity and thermal stability was performed. Electrophoretic blotting and immune fixation was carried out following sodium dodecyl sulfate polyacrylamide gel electrophoresis or isoelectric focusing of lysate protein. These techniques did not reveal a major structural alteration of the protein that could account for the observed variation in enzyme activity or thermal stability. Future studies utilizing molecular genetic techniques should make it possible to determine the basis for inherited variations in human RBC COMT activity and thermal stability.  相似文献   

3.
数据挖掘在生物信息学中的应用   总被引:6,自引:0,他引:6  
借助各种应用数学和计算机技术 ,将大量积累并急需处理的生物信息数据利用起来 ,探索生物信息中的规律 ,是当前国内国际生物信息学研究的热点和重点。其中数据挖掘技术在生物信息研究中发挥着巨大的作用。  相似文献   

4.
Mallakpour S  Barati A 《Amino acids》2012,42(4):1287-1295
In this investigation, poly(vinyl alcohol) was chemically modified by the introduction of different amounts of N-phthaloyl-l-phenylalanine. The modification was carried out by the reaction of PVA hydroxyl groups with (2S)-3-phenyl-2-phthalimidylpropanoyl chloride using N,N-dimethyl acetamide/lithium chloride as a reaction media. The novel copolymers obtained were characterized by spectroscopic techniques, elemental analysis, X-ray diffraction and thermal methods. Optical rotation and viscosities were also measured. The degree of esterification was determined by 1H-NMR. The influence of reagent molar ratio on the degree of modification was also evaluated. The vinyl(3-phenyl-2-phthalimidopropanoate) content in the copolymer was attained up to 52%. Thermal stability of the copolymers was checked by thermogravimetric analysis and differential thermogravimetric analysis. All copolymers displayed improved thermal stability compared to the parent polymer.  相似文献   

5.
In the present article the influence of salts and additives, such as trehalose, NaCl, ornithine, sodium phosphate and ammonium sulphate, on ornithine carbamoyltransferase (OCTase) is investigated in order to study the OCTase stabilization process as a function of solutes and to point out the fundamental role played by an enhancement of hydrophobic interactions. The synergic use of different techniques, such as neutron spectroscopy, UV–vis spectroscopy, activity and thermal measurements, allows to highlight the cosolute capability to avoid thermal inactivation, to induce important changes in secondary and tertiary enzyme structure and to stabilize biological macromolecules.  相似文献   

6.
This study was carried out to determine the possibility of the psychrophilic methane fermentation of the excess sludge produced from fish-processing wastewater treatment. Three different kinds of seed sludge, named M seed sludge, K seed sludge and KL seed sludge were used for batch methane fermentation in Erlenmeyer flasks. M seed sludge was mesophilic, while the other two were prepared in our laboratory by soil collection to obtain a psychrophilic biological community. The effects of temperature on the total volume of biogas generated and on the rate of biogas generation were examined. The activity of K seen sludge with respect to gas yield at 15°C was found to be 1.6-fold higher than that of M seed sludge. Enrichment techniques were then used to accumulate psychrophilic bacteria in KL seed sludge, and the activity at 15°C increased by about two times due to these techniques. Comparison of the three kinds of seed sludge indicates that methane fermentation at low temperature may be feasible, and therefore further study to isolate the psychrophilic bacteria in anaerobic digestion is needed.  相似文献   

7.
All biological bodies live in a thermal environment with the human body as no exception, where skin is the interface with protecting function. When the temperature moves out of normal physiological range, skin fails to protect and pain sensation is evocated. Skin thermal pain is one of the most common problems for humans in everyday life as well as in thermal therapeutic treatments. Nocicetors (special receptor for pain) in skin play an important role in this process, converting the energy from external noxious thermal stimulus into electrical energy via nerve impulses. However, the underlying mechanisms of nociceptors are poorly understood and there have been limited efforts to model the transduction process. In this paper, a model of nociceptor transduction in skin thermal pain is developed in order to build direct relationship between stimuli and neural response, which incorporates a skin thermomechanical model for the calculation of temperature, damage and thermal stress at the location of nociceptor and a revised Hodgkin-Huxley form model for frequency modulation. The model qualitatively reproduces measured relationship between spike rate and temperature. With the addition of chemical and mechanical components, the model can reproduce the continuing perception of pain after temperature has returned to normal. The model can also predict differences in nociceptor activity as a function of nociceptor depth in skin tissue.  相似文献   

8.
灰霉病由灰葡萄孢侵染所致,化学防治是目前最常用的治理方法,而随着杀菌剂的广泛使用,抗药菌株频繁出现。本文就近年来已研究报道的灰葡萄孢菌的抗药分子位点进行了系统总结,包括六大类杀菌剂,涉及5个基因;对灰霉病菌抗药位点的分子检测方法进行了综述,包括测序法、CAPS、ARMS、Tetra primer ARMS-PCR、AS real-time PCR、ASPPAA PCR和双杂交探针法,通过对不同检测方法进行比较分析,指出现有技术存在的问题并展望未来高通量的检测方法的发展方向。  相似文献   

9.
The distribution of thermoreceptor systems that initiate step-up and step-down thermophobic responses in bisected cells of Blepharisma was examined. Anterior cell fragments responded by ciliary reversal to a step-down in temperature and by repression of spontaneous ciliary reversal to a step-up. Posterior fragments responded by ciliary reversal to a step-up in thermal stimulation and by repression of spontaneous ciliary reversal in response to step-down stimulation. Results indicate that two kinds of thermoreceptor systems exist in the anterior half of each cell; one is responsible for ciliary reversal induced by step-down stimulation, and the other is responsible for repression of the ciliary reversal caused by step-up thermal stimulation. Likewise, there are also two kinds of thermoreceptor systems in the posterior half of the cell; one is responsible for ciliary reversal in response to a step-up in temperature, and the other is responsible for the repression of ciliary reversal on a step-down in thermal stimulation. Below about 27°C, intact cells showed ciliary reversal only when a step-down in thermal stimulation occurred, while above about 27°C cells only responded to a step-up in thermal stimulation. At about 27°C there was a switch in the dominant response from the anterior to the posterior half of an individual cell.  相似文献   

10.
董翠玲  刘建  王方忠  于涛 《四川动物》2007,26(4):878-880
山东昆嵛山国家森林公园有丰富的野生动植物资源,优美的景色,丰厚的文化底蕴,优越的地理位置,是开展生态旅游的理想之地。本文在综合评价昆嵛山独特的生态旅游资源优势的基础上,分析了旅游业可能给当地生态环境带来的负面影响,并提出了昆嵛山生态旅游资源保护与可持续开发利用的对策建议,以期推动昆嵛山生态旅游业发展。  相似文献   

11.
In recent years, there has been a tremendous increase in the papers published on synthetic recognition elements. Molecularly imprinted polymers (MIPs), also referred to as “man‐made mimics” of antibodies, are able to rebind their template molecules with high affinity. Advantages compared with those of natural receptors include their excellent thermal and chemical stability, low cost, and ease of the production process. However, their use in commercial biosensors is limited owing to the difficulty to incorporate MIPs into suitable sensing platforms and traditional detection techniques, such as chromatography, that require bulky and sophisticated equipment. In this review, we evaluate the potential to use MIPs combined with thermal read‐out for the detection of low‐weight organic molecules. We discuss thermal methods to study MIP‐template complexation and to determine neurotransmitters concentrations. In particular, we highlight the heat‐transfer method, a recent technique that is straightforward and low cost and requires minimal instrumentation. Until now, sample preparation involves a 2‐step process, making it time‐consuming, and measuring biological samples is difficult owing to the noise in the signal. Different sample preparation methods are discussed, and it will be demonstrated how this affects the thermal response. An outlook is given in novel methods that can simplify and speed up sample preparation. Finally, we show a novel thermal technique, which is based on the analysis of transport of thermal waves rather than evaluating the fixed heat‐transfer resistance. Through applying the concept of thermal waves, signal‐noise ratio is significantly increased, which results in lower detection limits and has potential for the study of biological samples.  相似文献   

12.
This mini-review has investigated the recent progress regarding gold nanostructures capacities of energy absorption for thermal therapy applications. Unselective thermal therapy of malignant and normal tissues could lead to irreversible damage to healthy tissues without effective treatment on target malignant tissues. In recent years, there has been a considerable progress in the field of cancer thermal therapy for treating target malignant tissues using nanostructures. Due to the remarkable physical properties of the gold nanoparticle, it has been considered as an exceptional element for thermal therapy techniques. Different types of gold nanoparticles have been used as energy absorbent for thermal therapy applications under several types of energy exposures. Electromagnetic, ultrasound, electric and magnetic field are examples for these energy sources. Well-known plasmonic photothermal therapy which applies electromagnetic radiation is under clinical investigation for the treatment of various medical conditions. However, there are many other techniques in this regard which should be explored.  相似文献   

13.
Three kinds of experiments were carried out in a climatic chamber: experiments with warm load on the whole body at 36 degrees C (4 subjects); experiments at 36 degrees C with reduction of thermal load (28 degrees C) on the left leg (right leg at 36 degrees C) (8 subjects); and experiments at 36 degrees C with antisymmetric thermal load on the legs of 44 degrees C (right leg) and 28 degrees C (left leg), which resulted in additional thermal loads of +/- 30 W/leg (8 subjects). The additional thermal loads, which were applied via two climatic boxes, produced measurable effects on sweat rate when applied to one leg only. In comparison to the experiment 1, experiment 2 brought about a significant reduction of local evaporation on the left leg. With antisymmetric thermal loads on both legs (experiment 3), which did not influence the overall thermal balance, there was no significant influence on local evaporation, although significant changes of local temperatures were measured. It is suggested that the well-known regulatory models, declaring local, mean skin, and core temperatures as local evaporation drive should be supplemented with an important additional feature: local control of evaporation by local skin temperature may be blocked by an overall thermal balance.  相似文献   

14.
Cognitive Structure and Informant Accuracy   总被引:5,自引:0,他引:5  
The problem of informant accuracy is examined in light of principles of memory organization from cognitive psychology. These principles turn out to be powerful, not only in explaining overall patterns of informant error, but in predicting details about the types of errors made. Predictions are made in terms both of different kinds of informants and different kinds of objects. All the predictions are strongly supported by the data. Finally, in the light of these results, two strategies are developed. The "best" informants, it seems, can be used to reveal long-range stable patterns of events, and the "worst" informants can be used to reveal the details of a particular event of special interest.  相似文献   

15.
Summary A study of karyotypes and neutrophil alkaline phosphatase (NAP) was carried out for 66 parents (33 couples) of trisomy 21 children and for 60 control parents (30 couples). Enzyme activity was determined simultaneously by biochemical and cytochemical techniques. In the mothers of trisomy 21 children we found: (a) by biochemical techniques, a significant increase of NAP activity in polymorphonuclear leukocyte (PMN) homogenates (P<0.01) and a lower supernatant/pellet ratio (P<0.01); (b) by cytochemical techniques (with or without thermal and urea treatments) NAP activity was significantly higher (P<0.001) than in control mothers; in the fathers, the two techniques gave normal NAP activity results.  相似文献   

16.
基于Biolog-FF技术的金霉素降解真菌的碳代谢特征研究   总被引:1,自引:0,他引:1  
【目的】利用Biolog-FF技术对4种不同金霉素降解真菌代谢95种碳源特征进行测定分析。【方法】测定不同时段4种真菌对95种碳源代谢的吸光值,并将4种真菌分别接种到金霉素药渣固废中,测定不同发酵时间药渣中的总有机碳含量。【结果】4种真菌利用碳源种类和活性差异较大,桔青霉LJ318、哈茨木霉LJ245、小刺青霉LJ236、草酸青霉LJ302能够利用碳源数量依次为41、39、15和14种;菌株LJ245和LJ318利用碳源的平均活性显著高于菌株LJ236和LJ302;4种真菌能够较好利用的碳源类型为糖类、氨基酸类、聚合物类等物质。【结论】菌株LJ245和LJ318代谢药渣中的碳源明显快于菌株LJ236和LJ302,这与Biolog方法测定结果趋势一致。Biolog-FF技术是一种快速测定真菌单菌落碳代谢特征的有效方法。研究为探讨真菌碳代谢特征与生物降解环境残留金霉素提供了科学依据。  相似文献   

17.
城市热环境定量评价技术研究进展及发展趋势   总被引:1,自引:1,他引:0  
自“城市热岛”概念提出以来,城市热环境定量评价一直是城市气候与环境研究领域的重要内容.随着空间信息技术与计算机模拟技术的不断发展,城市热环境定量评价的技术手段和方法也取得了长足进步.从最初单一利用气象站历史数据对城市宏观尺度热环境进行数理统计分析,逐步发展到综合利用地面气象观测、热红外遥感、数值模式模拟等多种技术对不同尺度热环境进行动态模拟与预测.本文系统回顾了地面气象观测、热红外遥感、数值模式模拟3类城市热环境定量评价技术的发展历程,并总结了各类技术的优缺点、适用性及发展趋势,以期为今后的城市热环境评价与优化研究提供参考.  相似文献   

18.
Calling behaviour is strongly temperature‐dependent and critical for sexual selection and reproduction in a variety of ectothermic taxa, including anuran amphibians, which are the most globally threatened vertebrates. However, few studies have explored how species respond to distinct thermal environments at time of displaying calling behaviour, and thus it is still unknown whether ongoing climate change might compromise the performance of calling activity in ectotherms. Here, we used new audio‐trapping techniques (automated sound recording and detection systems) between 2006 and 2009 to examine annual calling temperatures of five temperate anurans and their patterns of geographical and seasonal variation at the thermal extremes of species ranges, providing insights into the thermal breadths of calling activity of species, and the mechanisms that enable ectotherms to adjust to changing thermal environments. All species showed wide thermal breadths during calling behaviour (above 15 °C) and increases in calling temperatures in extremely warm populations and seasons. Thereby, calling temperatures differed both geographically and seasonally, both in terrestrial and aquatic species, and were 8–22 °C below the specific upper critical thermal limits (CTmax) and strongly associated with the potential temperatures of each thermal environment (operative temperatures during the potential period of breeding). This suggests that calling behaviour in ectotherms may take place at population‐specific thermal ranges, diverging when species are subjected to distinct thermal environments, and might imply plasticity of thermal adjustment mechanisms (seasonal and developmental acclimation) that supply species with means of coping with climate change. Furthermore, the thermal thresholds of calling at the onset of the breeding season were dissimilar between conspecific populations, suggesting that other factors besides temperature are needed to trigger the onset of reproduction. Our findings imply that global warming would not directly inhibit calling behaviour in the study species, although might affect other temperature‐dependent features of their acoustic communication system.  相似文献   

19.

1. 1. Thermal comfort investigations have been carried out in Hungary from the second half of the 1970s, partly in laboratories and partly in the field, with humans and thermal manikins.

2. 2. The most important series of measurements have been made in the following fields: comparison of different heating systems from the point of view of thermal comfort, energy consumption and local discomfort; comparison of different heat and sunshine protection formulations; determination of acceptable temperature for different activities; checking different kinds of ventilation; examination of the thermal comfort conditions of disabled persons; determination of different clothing, e.g. the clo values of uniforms and polar suits, etc.

3. 3. This paper deals with the methods and results of laboratory and site examinations.

Author Keywords: Thermal comfort; heating systems; manikin; energy consumption; disabled persons  相似文献   


20.
Abstract Bioleaching is carried out by chemolithotrophic microorganisms, most of them belonging to the genera Thiobacillus and Leptospirillum . The role of the mixotrophic species T. cuprinus in this process is controversial, since its ecological study applying classical detection techniques to natural or industrial environments is very difficult. For this reason, we have developed an alternative method based on PCR-mediated detection using specific oligonucleotide primers that target variable regions of the 23S rRNA coding gene and of the 16S/23S intergenic spacer region. Specificity and sensitivity of PCR amplifications performed with both kinds of primers were studied.  相似文献   

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