Dual-Roof Solar Greenhouse—A Novel Design for Improving the Heat Preserving Capacity in Northern China

Dual-roof solar greenhouse, a new style of solar greenhouse, was designed in this study intending to reduce heat loss in cold time and improve land use efficiency in Beijing, the Capital city of China. Designing and applying the dual-roof greenhouse in metropolitan area had dual effects of saving energy and enhancing land use efficiency. According to the monitoring study and analysis conducted in winter of 2012, the averaged night temperature of south room was about 12.1°C in December, which was satisfying for growing average leaf vegetables. Total energy saved by dual-roof in whole winter was quantified as 1.1 × 107 MJ&#46yr-1 (winter), potentially about 37.4 t coal was saved in Beijing area during whole winter-growing period. Considering the application of north room, the land use efficiency was improved by 62.5% in dual-roof solar greenhouse.

Seasonality of PSII thermostability and water use e ffi ciency of in situ mountainous Norway spruce(Picea abies)

The stability of monocultural,even-aged spruce forests at lower altitudes in Central Europe is seriously threatened by the prospects of global climate change.The thermostability and water use efficiency of their photo synthetic apparatus might play a vital role in their successful acclimation.In this study,photo systemⅡ(PSⅡ)performance(OJIP transient,rapid light curves)and thermostability were analyzed in Norway spruce(Picea abies(L.)Karst.)throughout the growing season of the exceptionally warm year 2018(May-September)in the Western Carpathians,Slovakia.These measurements were accompanied by analysis of pigment concentrations in the needles.In addition,gas-exchange temperature curves were produced weekly from June until September to obtain intrinsic water use efficiencies.At the beginning of the growing season,needles exposed to heat stress showed significantly higher basal fluorescence and lower quantum yield,performance index,critical temperature thresholds of PSII inactivation and nonphotochemical yield in comparison to other months.The overall thermostability(heat-resistance)of PSII peaked in July and August,reflected in the lowest basal fluorescence and the highest quantum yield of PSII,critical temperature thresholds and yield of non-photochemical quenching under heat stress.Additionally,the ratio between chlorophyll and carotenoids was the highest in August and had a positive impact on PSII thermostability.Moreover,the high-temperature intrinsic water use efficiency was significantly higher during July and August than in June.Results show that15-year-old trees of Picea abies at 840 m a.s.l.exhibited acclimative seasonal responses of PSII thermostability and intrinsic water use efficiency during an exceptionally warm year.Our results suggest that mountainous P.abies at lower altitudes can acclimate their photosynthetic apparatus to higher temperatures during summer.

Yields,growth and water use under chemical topping in relations to row configuration and plant density in drip-irrigated cotton

Background Water deficit is an important problem in agricultural production in arid regions.With the advent of wholly mechanized technology for cotton planting in Xinjiang,it is important to determine which planting mode could achieve high yield,fiber quality and water use efficiency(WUE).This study aimed to explore if chemical topping affected cotton yield,quality and water use in relation to row configuration and plant densities.Results Experiments were carried out in Xinjiang China,in 2020 and 2021 with two topping method,manual topping and chemical topping,two plant densities,low and high,and two row configurations,i.e.,76 cm equal rows and 10+66 cm narrow-wide rows,which were commonly applied in matching harvest machine.Chemical topping increased seed cotton yield,but did not affect cotton fiber quality comparing to traditional manual topping.Under equal row spacing,the WUE in higher density was 62.4%higher than in the lower one.However,under narrow-wide row spacing,the WUE in lower density was 53.3%higher than in higher one(farmers’practice).For machine-harvest cotton in Xinjiang,the optimal row configuration and plant density for chemical topping was narrow-wide rows with 15 plants m-2 or equal rows with 18 plants m-2.Conclusion The plant density recommended in narrow-wide rows was less than farmers’practice and the density in equal rows was moderate with local practice.Our results provide new knowledge on optimizing agronomic managements of machine-harvested cotton for both high yield and water efficient.

Urban Heat Island and Land Use/Cover Dynamics Evaluation in Enugu Urban, Nigeria

This study specifically estimated the effect of land use/cover change (LULC) processes on land surface temperature (LST) in Enugu urban and its suburbs. With Landsat images and supervised classification technique, four LULC classes comprising built-up areas, vegetation, rock outcrop, bare ground/farmland areas were delineated. The LST was extracted from the thermal bands of the images. The rate of change in land cover classes between 2009 and 2018 showed that from 2009 to 2013, built-up areas increased from 31.65% to about 47.5%, while vegetation cover decreased from 18.43% to 11.23%. Also, the periods witnessed about 8.69 km2 of vegetation being converted to other land surfaces. The trend in the LST in Enugu urban showed the highest mean temperatures of 34.5°C in 2018 and 32.26°C in 2015. However, in 2013 there was a slight decrease in mean LST to 31.65°C which further decreased to 31.26°C in 2009. This change in temperature suggests that urbanisation could have significant effect on the micro-climate of Enugu city. Result also revealed weak relationships between LULC classes and the LST throughout the years. The results of the surface heat intensity for the urban and rural areas showed general increase over the years and this suggests that rural areas are also experiencing high temperature which could be due to the loss of vegetation, increase in artificial surfaces and urban encroachment. Findings from this study could be useful for effective urban land-use planning, policy development and management in Nigeria, and elsewhere.

Spatiotemporal dynamics of land use/land cover(LULC)changes and its impact on land surface temperature:A case study in New Town Kolkata,eastern India

Rapid urbanization creates complexity,results in dynamic changes in land and environment,and influences the land surface temperature(LST)in fast-developing cities.In this study,we examined the impact of land use/land cover(LULC)changes on LST and determined the intensity of urban heat island(UHI)in New Town Kolkata(a smart city),eastern India,from 1991 to 2021 at 10-a intervals using various series of Landsat multi-spectral and thermal bands.This study used the maximum likelihood algorithm for image classification and other methods like the correlation analysis and hotspot analysis(Getis–Ord Gi^(*) method)to examine the impact of LULC changes on urban thermal environment.This study noticed that the area percentage of built-up land increased rapidly from 21.91%to 45.63%during 1991–2021,with a maximum positive change in built-up land and a maximum negative change in sparse vegetation.The mean temperature significantly increased during the study period(1991–2021),from 16.31℃to 22.48℃in winter,29.18℃to 34.61℃in summer,and 19.18℃to 27.11℃in autumn.The result showed that impervious surfaces contribute to higher LST,whereas vegetation helps decrease it.Poor ecological status has been found in built-up land,and excellent ecological status has been found in vegetation and water body.The hot spot and cold spot areas shifted their locations every decade due to random LULC changes.Even after New Town Kolkata became a smart city,high LST has been observed.Overall,this study indicated that urbanization and changes in LULC patterns can influence the urban thermal environment,and appropriate planning is needed to reduce LST.This study can help policy-makers create sustainable smart cities.

Variation of fluxes of water vapor, sensible heat and carbon dioxide above winter wheat and maize canopies

Surface energy fluxes were measured using Bowen-Ratio Energy Balance technique (BREB) and eddy correlation system at Luancheng of Hebei Province, on the North China Plain from 1999 to 2001. Average diurnal variation of surface energy fluxes and CO2 flux for maize showed the inverse “U” type. The average peak fluxes did not appear at noon, but after noon. The average peak CO2 flux was about 1.65 mg m-2 s-1. Crop water use efficiency (WUE) increased quickly in the morning, stabilized after 10:00 and decreased quickly after 15:00 with no evident peak value. The ratio of latent heat flux (λE) to net solar radiation (Rn) was always higher than 70% during winter wheat and maize seasons. The seasonal average ratio of sensible heat flux (H) divided byR n stayed at about 15% above the field surface; the seasonal average ratio of conductive heat flux (G) divided by Rn varied between 5% and 13%, and the averageG/R> n from the wheat canopy was evidently higher than that from the maize canopy. The evaporative fraction (EF) is correlated to the Bowen ratio in a reverse function.EF for winter wheat increased quickly during that revival stage, after the stage, it gradually stabilized to 1.0, and fluctuated around 1.0. EF for maize also fluctuated around 1.0 before the later grain filling stage, and decreased after that stage.

Effects of biodegradable mulch on soil water and heat conditions,yield and quality of processing tomatoes by drip irrigation

To combat the problem of residual film pollution and ensure the sustainable development of agriculture in oasis areas,a field experiment was carried out in 2019 at the Wuyi Farm Corps Irrigation Center Test Station in Urumqi,Northwest China.Four types of biodegradable mulches,traditional plastic mulchs and a control group(bare land;referred to as CK)were compared,including a total of six different treatments.Effects of mulching on soil water and heat conditions as well as the yield and quality of processing tomatoes under drip irrigation were examined.In addition,a comparative analysis of economic benefits of biodegradable mulches was performed.Principal component analysis and gray correlation analysis were used to evaluate suitable mulching varieties for planting processing tomatoes under drip irrigation.Our results show that,compared with CK,biodegradable mulches and traditional plastic mulch have a similar effect on retaining soil moisture at the seedling stage but significantly increase soil moisture by 0.5%-1.5%and 1.5%-3.0%in the middle and late growth periods(P<0.050),respectively.The difference in the thermal insulation effect between biodegradable mulch and plastic mulch gradually reduces as the crop grows.Compared with plastic mulch,the average soil temperature at 5-20 cm depth under biodegradable mulches is significantly lowered by 2.04°C-3.52°C and 0.52°C-0.88°C(P<0.050)at the seedling stage and the full growth period,respectively,and the water use efficiency,average fruit yield,and production-investment ratio under biodegradable mulches were reduced by 0.89%-6.63%,3.39%-8.69%,and 0.51%-6.33%(P<0.050),respectively.The comprehensive evaluation analysis suggests that the black oxidized biological double-degradation ecological mulch made from eco-benign plastic is the optimal film type under the study condition.Therefore,from the perspective of sustainable development,biodegradable mulch is a competitive alternative to plastic mulch for large-scale tomato production under drip irrigation in the oasis.

A reversibly used cooling tower with adaptive neuro-fuzzy inference system

An adaptive neuro-fuzzy inference system(ANFIS) for predicting the performance of a reversibly used cooling tower(RUCT) under cross flow conditions as part of a heat pump system for a heating mode in winter was demonstrated.Extensive field experimental work was carried out in order to gather enough data for training and prediction.The statistical methods,such as the correlation coefficient,absolute fraction of variance and root mean square error,were given to compare the predicted and actual values for model validation.The simulation results predicted with the ANFIS can be used to simulate the performance of a reversibly used cooling tower quite accurately.Therefore,the ANFIS approach can reliably be used for forecasting the performance of RUCT.

Study of Urban Heat Island Trends to Aid in Urban Planning in Nakuru County-Kenya

Urban Heat Island (UHI) is a phenomenon characterized by higher surface and atmospheric temperatures in urbanized areas as compared to the surrounding rural areas. This phenomenon is a consequence of increase in Land Surface Temperatures (LST) as a result of trapped heat energy on the surface. The objective of this study is establishing the trends in and relationship between LST and land use/land cover in Nakuru County as it seeks to achieve the ultimate goal to contain the UHI effect. Urban heat island inference was based on the generation of a time series set of Landsat imagery, with particular emphasis on the thermal band. Land use/land cover mapping was conducted using maximum likelihood classification techniques, and this, like the LST, is generated in a time series fashion from 1989 to 2015. Accuracy assessment was conducted in order to give confidence in the classification results. The accuracy of the development was assessed using observed temperature data as recorded by the ground stations at the Kenya Meteorological Department. This study employed Normalized NDVI and NDBI to investigate the variation land use/land cover. Results revealed that over the years, settlement has been on an upward trend in terms of area whereas forests have been decreasing due to deforestation. Also, the land surface temperatures have been increasing over the years. In order to qualify this, the correlation between LST and Land Use change was conducted and it indicated that changes to settlement/urban increased proportionately with Land Surface Temperature.

Role of Turbulent Heat Fluxes over Land in the Monsoon over East Asia

Atmospheric heat and moisture over land are fundamental drivers of monsoon circulations. However, these drivers are less frequently considered in explaining the development and overall intensity of monsoons than heat and moisture over the ocean. In this study, the roles of turbulent heat fluxes over land in the monsoon system over East Asia are examined using Climatic Research Unit observations and European Centre for Medium-Range Weather Forecasts reanalysis, and they are further explored using simulated sensible (H) and latent (LE) heat fluxes from an ecosystem model (Predicting Ecosystem Goods and Services Using Scenarios or PEGASUS). Changes in the H fluxes over the land during the pre-monsoon season (March-May: MAM) affect the differential heating between land and ocean, which in turn controls monsoon development. In July, an intensified contrast of the mean sea level pressure between land and ocean is observed during the years of stronger land-sea H contrast in MAM, which results in enhanced onshore flows and more rainfall over southern East Asia. After monsoon onset, the contrast of H is influenced by monsoon rainfall through the cooling effect of precipitation on surface air temperature. During the monsoon season (June-September: JJAS), LE fluxes are more important than H fluxes, since LE fluxes over land and ocean affect overall monsoon intensity through changes in the land-sea contrast of turbulent heat fluxes. Significantly increased monsoon rainfall over western East Asia is observed during the years of larger LE over the land in JJAS. In ecosystem modeling, we find that the monsoon can be weakened as potential (natural) vegetation is converted to bare ground or irrigated cropland. Simulated H fluxes in MAM and LE fluxes in JJAS over the land significantly decrease in irrigated crop and bare ground scenarios, respectively, which play crucial roles in controlling monsoon development and overall intensity.

Augmenting the Heat Sink for Better Heat Dissipation

Heat sinks were invented to absorb heat from an electronic circuit conduct, and then to dissipate or radiate this heat to the surrounding supposedly, ventilated space, at a rate equal to or faster than that of its buildup. Ventilation was not initially recognized as an essential factor to thermal dispersion. However, as electronic circuit-boards continued to heat up, circuit failure became a problem, forcing the inclusion of miniaturized high speed fans. Later, heat sinks with fins and quiet fans were incorporated in most manufactured circuits. Now heat sinks come in the form of a fan with fans made to function as fins to disperse heat. Heat sinks absorb and radiate excess heat from circuit-boards in order to prolong the circuit’s life span. The higher the thermal conductivity of the material used the more efficient and effective the heat sink is. This paper is an attempt to theoretically design a heat sink with a temperature gradient lower than that of the circuit board’s excess heat.

Climate &Sustainability Implications of Land Use Alterations in an Urbanizing Region: Raleigh-Durham, North Carolina

Urban climate is the most immediate manifestation of the warming global climate for the majority of people on earth. Nearly half of those people live in small to medium sized cities, an understudied scale in urban climate research. Widespread characterization would be useful to decision makers in planning and design for land use decisions. Using a multi-method approach, the mesoscale UHI in the study region is characterized and the secular trend over the last sixty years evaluated. Under isolated ideal conditions the findings indicate a UHI of 5.3℃ ± 0.97℃ to be present in the study area, the magnitude of which is growing over time.

涡轮叶片前腔冲击/气膜复合冷却与单一气膜冷却结构对比实验研究

为了对比前腔冲击/气膜复合冷却结构和单一气膜冷却结构对涡轮叶片冷却特性的影响,本文以完整叶片为测试对象,针对低导热系数叶片进行了内外耦合综合冷却换热实验。测试叶片前腔压力面采用单一气膜冷却和冲击/气膜复合冷却结构。实验采用红外热像仪测量了叶片表面的温度分布,分析了吹风比(M)对于叶片综合冷却效率的影响。研究了不同工况下两种冷却结构对涡轮叶片冷却特性的影响。实验结果表明,由于叶片表面压力分布不均匀,更靠近前缘的第一排气膜孔处冷却效率小于第二排,且吹风比越小该现象越明显。相较于传统的气膜冷却叶片,冲击/气膜复合冷却叶片在M=0.4,1.2,2.0的情况下,冷却效率分别提升了3.45%,6.33%,5.64%。同时,冲击冷却造成的冷却剂动能损失能够削弱高吹风比下冷却剂出流后脱离壁面的情况发生。

醒脑开窍针刺法干预实验性脑梗塞大鼠热休克蛋白基因表达的研究

目的 :揭示醒脑开窍针刺法治疗脑梗塞的分子机制。方法 :采用分子杂交的技术 ,观察了实验性脑梗塞大鼠缺血区脑组织HSP70 mRNA的转录水平 ,并观察了醒脑开窍针刺法对缺血区脑组织HSP70 mRNA表达的干预作用。 结果 :发现醒脑开窍针刺法可增加梗塞区皮质、纹状体、海马HSP70 基因的表达。证实了醒脑开窍针刺法对缺血后的脑细胞的保护作用优于常规针刺法 。

热敏穴灸治疗肌筋膜疼痛综合征：多中心随机对照研究

目的:观察热敏穴灸治疗肌筋膜疼痛综合征(MPS)的临床疗效,以期肯定该项新疗法治疗MPS的高效性。方法:采用3个中心、单盲、随机、对照研究方法,将107例患者随机分为观察组(57例)和对照组(50例)。观察组给予热敏穴灸治疗,对照组给予针刺加拔罐加TDP常规治疗。采用简化麦吉尔疼痛量表为观察指标,以治疗前后疼痛评定指数(PRI)、视觉模拟评分(VAS)和现时疼痛强度(PPI)的变化来评价疗效。结果:观察组的愈显率为86.0%,优于对照组的24.0%(P<0.001)。2组PRI、VAS、PPI积分较治疗前有极显著改善(P<0.001),且观察组优于对照组(P<0.001)。结论:热敏穴灸疗法对MPS具有高效性。

灸法治疗热证的研究进展

文章概述了建国以来临床应用灸法治疗热证及其原理研究情况。所治疗病症涉及内、外、皮、儿、五官、传染等二十余种,证型包括实热证和虚热证。近年来,临床研究取得新进展,部分报道设立了对照组和观察指标;实验研究表明灸法能提高机体免疫功能,增加白细胞计数,具有抑菌、退热和改善微循环的作用,为重新评价灸法的适应证提供了科学依据。

清热解毒活血法外治类风湿关节炎的临床研究

目的:评价清热解毒活血法外治类风湿关节炎(RA)活动期关节炎症的临床疗效和安全性。方法:纳入120例辨证为热毒蕴结、气滞血瘀型RA活动期的患者。随机分为治疗组60例,对照组60例,治疗组采用具有清热解毒活血作用的消炎止痛膏,对照组采用安慰剂,1贴/d,选择1个受累关节外用。每个疗程7 d,共治疗2个疗程,观察关节肿痛总积分(包括疼痛、肿胀、关节发热、压痛等);疼痛视觉模拟评分法(Visual Analogue Scale/Score,简称VAS评分)及血沉(ESR)变化。结果:治疗组总效率(60.4%)明显优于对照组(20.0%)。完成治疗后治疗组的关节症状总积分、VAS评分均明显改善(P<0.01),且显著优于对照组(P<0.01)。治疗组ESR较治疗前明显下降(P<0.01),但与对照组比较无统计学意义(P>0.05)。2组不良事件无统计学意义。结论:清热解毒活血外治法能明显改善类风湿关节炎活动期关节红肿热痛症状,起效较快,安全性好,值得进一步深入研究并在临床推广应用。

中低温余热与甲醇化学间冷相结合热力循环研究

本文基于探讨中低温余热与清洁合成燃料间接燃烧相结合的能量释放新思路,揭示同时降低燃烧过程品位损失和提高低品位能的功能力的机理。采用图象佣分析方法,明确地指出甲醇间接燃烧佣损失减少的原因。从系统集成角度,探讨燃气轮机循环中利用压气机间冷的低温热与甲醇吸热裂解相结合的热力循环,并研究和揭示该循环热力特性规律。本文为能量释放新机理的研究和构思新颖中低温余热的热力循环提供基础依据。

烧结多孔层通道内沸腾传热特性研究

用试验研究并分析了垂直烧结多孔层通道内通道间隙、粒度、层厚及视观高度对沸腾传热的影响。研究表明，对在同一热流下存在一个最佳通道间隙及粉末粒度范围。适当增大多孔层厚度将有利于沸腾传热系数的提高，而热虹吸高度的降低将不利于沸腾传热系数的增大。

针罐埋线与电针治疗胃肠实热型单纯性肥胖临床疗效对比

目的:寻找能够提高治疗胃肠实热型单纯性肥胖临床疗效的方法。方法:将82例胃肠实热型单纯性肥胖症患者随机分成A组(40例)、B组(42例)。A组采用电针加走罐、埋线法治疗;B组单纯采用电针治疗。两组电针取穴相同(中脘、下脘、气海等),A组除电针外在任、督、脾、胃、膀胱经脉走罐和穴位埋线。对其疗效、主要症状、体重指标、腰围、臀围和腰臀比值进行对比观察。结果:A组总有效率为90.0%,明显优于B组的78.6%(P<0.01),在体重、体质指数(BMI)和腰围、臀围值下降方面,两组比较差异亦有显著性意义(P<0.05,P<0.01);对消谷善饥、大便秘结、颜面痤疮等主要症状的改善方面,A组亦优于B组(P<0.01)。结论:针罐埋线并用治疗胃肠实热型单纯性肥胖能提高疗效,是治疗本病较佳的方法。