期刊文献+
共找到2,343篇文章
< 1 2 118 >
每页显示 20 50 100
Effects of Nitrogen Management on the Yield of Winter Wheat in Cold Area of Northeastern China 被引量:10
1
作者 LI Lian-peng LIU Yuan-ying +1 位作者 LUO Sheng-guo PENG Xian-long 《Journal of Integrative Agriculture》 SCIE CSCD 2012年第6期1020-1025,共6页
A plot experiment including four treatments, CK (N 105 kg ha-1 as urea, including a basal N application of 35 kg ha-I and a topdressing N 70 kg ha-1 at turned green stage) and optimized N management (OPT1, OPT2 and... A plot experiment including four treatments, CK (N 105 kg ha-1 as urea, including a basal N application of 35 kg ha-I and a topdressing N 70 kg ha-1 at turned green stage) and optimized N management (OPT1, OPT2 and OPT3, applied two-thirds, one-third and two-fifths N at jointing stage, respectively, total N 60 kg ha-l), was conducted to evaluate the effects of nitrogen management on growth and N uptake of winter wheat (Triticum aestivum), Dongnong 1, which is the first highly cold tolerant winter wheat in China. Index of population quality, N uptake and yield were determined. The ear-bearing tiller rate was increased by above 12%, and the leaf area index, biomass and N uptake were significantly decreased (P〈O.05) at jointing stage. OPT treatments increased the grain to leaf area ratio at heading stage, the dry matter weight and N uptake after heading by 14.3-27.9%, 11.6-28.7% and 118.1-161.8 %, respectively. The yield of the OPT treatments was increased by 14.2-37.5% compared with CK, and there was a significant difference (P〈0.05) between CK and OPT1 treatments. Harvest index and N partial factor productivity (PFP, kg grain yield per kg N applied) was clearly enhanced from 0.4 and 35.6 kg, respectively for CK to an average of 0.48 (P〈0.05) and 77.6 kg (P〈0.05) in the OPT treatments. These results indicated that the optimized N management increased the harvest index, yield and N use efficiency by decreasing the N application rate and postponing N application time, improved wheat population quality, controlled excessive growth in the vegetative stages and increased dry matter and N accumulation rates after heading. 展开更多
关键词 cold area winter wheat (Triticum aestivum) N management population quality YIELD
下载PDF
Effects of Site-Specific Nitrogen Management on Yield and Dry Matter Accumulation of Rice from Cold Areas of Northeastern China 被引量:6
2
作者 PENG Xian-long LIU Yuan-ying +3 位作者 LUO Sheng-guo FAN Li-chun SONG Tian-xing GUO Yan-wen 《Agricultural Sciences in China》 CAS CSCD 2007年第6期715-723,共9页
The effects of yield increase and mechanism of site-specific nitrogen management (SSNM) in five rice varieties from cold areas of northeastern China were studied. Plot experiment for critical SPAD value and experime... The effects of yield increase and mechanism of site-specific nitrogen management (SSNM) in five rice varieties from cold areas of northeastern China were studied. Plot experiment for critical SPAD value and experiments of two fertilization methods, SSNM and farmer's fertilization practice (FFP) were conducted to study their effects on the quality and dry matter accumulation of rice population, as well as N uptake. Compared with FFP, SSNM significantly decreased the average N rate by 33.8%, significantly increased average ear-bearing tiller rate and LAI for grain-filling stage by 12.3% and 14.1-27.6%, correspondingly, improved dry matter weight and N uptake after heading period by 4.3-29.1% and 11.8-55.1% (P 〈 0.05), and heightened recovery efficiency and agronomic efficiency by 38.5-133.4% (P 〈 0.05) and 39.8-194.3% (P 〈 0.05), respectively, as well as increased the average yield by 9.8% in 2004 and 2005. The results indicated that the accumulation rate of dry matter and N increased the rice yield and N use efficiency, because of improving rice population quality and increasing LAI after heading period. 展开更多
关键词 cold areas RICE site-specific nitrogen management YIELD dry matter N use efficiency
下载PDF
Discussion on the model of community management of chronic diseases in cold areas 被引量:1
3
作者 Rui Jiang Yuquan Zhao Yongchen Wang 《Frigid Zone Medicine》 2021年第1期17-22,共6页
Because of the overbearing low temperature,cold areas increase the morbidity and mortality of chronic non-communicable diseases(chronic diseases)in exposed populations.With the growth of the aging population and the s... Because of the overbearing low temperature,cold areas increase the morbidity and mortality of chronic non-communicable diseases(chronic diseases)in exposed populations.With the growth of the aging population and the superposition of lifestyle risk factors,the number of people with chronic diseases in cold areas is climbing,and the family and social burdens are rising.These health-threatening circumstances in the cold areas render the general practitioners to face serious challenges and difficulties in the community management of chronic diseases.This paper summarizes the current situation of chronic disease management in cold areas and explores the relevant management models so as to provide a useful reference for regional health construction,graded diagnosis and treatment,and prevention and control of chronic diseases in China. 展开更多
关键词 cold area chronic disease community management general practitioner
下载PDF
Effects of Rice Yield and Quality Across Accumulated Temperature Zone Planting in Cold Area
4
作者 Wang Qiu-ju Liu Feng +4 位作者 Gao Pan Gao Zhong-chao Chang Ben-chao Liu Yan-xia Zhang Li-li 《Journal of Northeast Agricultural University(English Edition)》 CAS 2015年第2期1-7,共7页
Five rice varieties were planted to determine the variation of the yield and quality traits in five different regions in a cold area of China. The results showed that the number of the panicles, the number of grains p... Five rice varieties were planted to determine the variation of the yield and quality traits in five different regions in a cold area of China. The results showed that the number of the panicles, the number of grains per panicle and percentage of head-milled rice displayed quadratic curves against the accumulated temperature, and the sterile rate decreased with greater accumulated temperature. However, 1 000-grain weight had no correlation with the accumulated temperature and protein content, amylose content and taste also had no obvious relation with the accumulated temperature. The results from the accumulated temperature differed with rice variety, so the temperature insensitive type variety should be proposed for production. 展开更多
关键词 RICE YIELD accumulated temperature cold area
下载PDF
Saving Strategy and Simulation Analysis of Green Log Walls in Severe Cold Area
5
作者 Hong-Peng Xu Si Li 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2014年第5期46-51,共6页
Log house is a traditional type of vernacular dwelling in Chinese cold area. It contains distinct regional characteristics and architectural cultures. In recent years,log house has come into vogue softly with the deve... Log house is a traditional type of vernacular dwelling in Chinese cold area. It contains distinct regional characteristics and architectural cultures. In recent years,log house has come into vogue softly with the development of wood techniques. However,log houses expend too much wood materials. There are also many negative aspects of this type of wood building which go against the criteria of energy conservation,and its high prime cost hinders the application as well. To solve these problems, the paper emphasizes using more environmental standardized techniques which save cost at the same time,and put forward technical strategy to improve the log walls. The optimization schemes are mainly divided into two categories: internal insulation and filled insulation. Each type of insulation is respectively derived two schemes through changing the thickness of main structure layers and insulation layer. Firstly,we use Weto software to calculate the timber volume of the four schemes,and it concludes that all the optimizations can save more timber than the prototype log wall with the section of 200 mm × 200 mm. Secondly,thermal comfort of each scheme is insulated in Design Builder.The results show that thermal insulation of filling type represents better than the other schemes. At last,we use thermal calculating formula to calculate thermal resistance of every scheme. Contrast to the energy efficiency standards of Heilongjiang Province, the data show that the four schemes meet the requirements of the specification. 展开更多
关键词 sever cold area log wall green wood building thermal comfort simulation
下载PDF
Contemporary understanding of the risk factors for chronic kidney disease in cold area
6
作者 Xinrui Wei Yongchen Wang 《Frigid Zone Medicine》 2022年第4期204-213,共10页
The management of chronic kidney disease(CKD)patients in cold areas is an important task in the daily practice of primary medical and health institutions.An important way to reduce the burden of CKD is to achieve earl... The management of chronic kidney disease(CKD)patients in cold areas is an important task in the daily practice of primary medical and health institutions.An important way to reduce the burden of CKD is to achieve early identification of and implement timely intervention on the relevant risk factors.Studies have shown that diet,alcohol,tobacco,air,sedentary and other factors in cold areas have negative impacts on human kidneys;yet,our current understanding of the effect of cold stimulation on CKD remains blurry.This paper introduces the research progress of risk factors related to CKD in cold areas and analytically summarizes the pathogenesis of CKD caused by cold stimulation,aiming to provide a reference work for the prevention,screening,evaluation,and management of CKD in cold areas. 展开更多
关键词 chronic kidney disease cold areas eating habits LIFESTYLE cold stimulation
下载PDF
Advances in the research field of osteoporosis in cold areas
7
作者 Ping Zhou Hanlu Zhang +2 位作者 Yizhen Nie Yimeng Zhang Yongchen Wang 《Frigid Zone Medicine》 2022年第1期1-9,共9页
While osteoporosis is a chronic disease caused by multiple factors,it is also a risk factor for fractures.At present,numerous risk factors for osteoporosis and secondary fractures have been identified,including sunlig... While osteoporosis is a chronic disease caused by multiple factors,it is also a risk factor for fractures.At present,numerous risk factors for osteoporosis and secondary fractures have been identified,including sunlight,physical fitness,gender,age,trauma,dietary habits,tobacco,alcohol,drugs,air quality,and genetics.Despite that factors such as long winters,short daylight hours,less daily physical activity,air pollution,low calcium and high salt diet,and sedentary lifestyle could negatively impact the bones of residents in the alpine regions of northern China,the direct effect of low-temperature stimulation on bone growth and development remains unclear.In this study,by reviewing current research progress related to osteoporosis and fracture risk in northern China,we proposed appropriate preventive measures for different risk factors to reduce the occurrence of osteoporosis and fracture in cold areas of northern China. 展开更多
关键词 OSTEOPOROSIS cold areas cold stimulation bone metabolism
下载PDF
Thermal adaptation in overheated residential buildings in severe cold area in China 被引量:6
8
作者 Zhaojun Wang Yuchen Ji +1 位作者 Jing Ren 侯恩哲 《建筑节能》 CAS 2017年第7期10-10,共1页
The winter in the severe cold area of China is long and cold. The mean outdoor temperature is about-10. 0 ℃ during the winter in Harbin,while the indoor air temperature is often above24 ℃. How does the indoor enviro... The winter in the severe cold area of China is long and cold. The mean outdoor temperature is about-10. 0 ℃ during the winter in Harbin,while the indoor air temperature is often above24 ℃. How does the indoor environment influence human thermal comfort and adaptation in such an overheated environment?A combined approach of spot-reading measurements and occupant interview s w as adopted in nine residential buildings of five communities during the heating period in 2013-2014. Tw enty residents w ere chosen as respondents. Totally 308 valid questionnaires w ere collected. The heating periods w ere separated into three phases based on the outdoor temperature.The results show that the mean indoor air temperatures in theearly-,mid-and late-heating periods w ere 23. 6 ℃,24. 3 ℃and 25. 0 ℃,respectively,w hich w ere larger than or close to the upper limit recommended by thermal comfort standards, and slightly higher than the related thermal neutral temperatures. With the heating process,the mean clothing insulation of residents decreased. Opening w indow s and reducing clothing w ere mainly taken by the residents to adapt to the overheated environment.The thermal neutral temperature has an upw ard tendency w ith the increasing indoor air temperature. On the other hand,overheating in residential buildings w ould make residents open w indow s,w hich may cause thermal discomfort and energy w aste. Therefore,the low er limit of the comfort indoor air temperature range should be suggested as the heating temperature,w hich could fully arouse residents' adaptation and achieve sustainable building designs. 展开更多
关键词 建筑节能 建筑设计 建筑风格 建筑材料
下载PDF
Study on Energy-saving Technology and Design Optimization of Facade in Cold and Severe Cold Area
9
作者 Wei Li Xin Zheng 《International Journal of Technology Management》 2013年第2期53-55,共3页
关键词 严寒地区 优化设计 节能技术 建筑围护结构 住宅节能 农村地区 寒冷地区 适宜技术
下载PDF
Occupancy of rooms in urban residential buildings by users in cold areas of China 被引量:1
10
作者 Qi Dong Zikai Ma Cheng Sun 《Building Simulation》 SCIE EI CSCD 2023年第3期483-497,共15页
Occupancy is used to represent the movements and locations of users among various zones of buildings,and it is the basis of all other daily energy consumption behaviors.This study investigated eight families in cold a... Occupancy is used to represent the movements and locations of users among various zones of buildings,and it is the basis of all other daily energy consumption behaviors.This study investigated eight families in cold areas of China based on occupancy measurements obtained in four main rooms,i.e.,living room,bedroom,kitchen,and bathroom.In particular,we analyzed the duration of user occupancy and hourly mean occupancy,and characterized their regular and random features.According to the results,we developed an event-based occupancy model using an inhomogeneous Markov chain,where the rooms were modeled and daily events were divided into three categories according to their randomness.We established a new method for conversion between event characteristic parameters and a transition probability matrix,as well as an overlap avoidance method for active events.The model was then validated using real data.The results showed that the model performed well in terms of two evaluation criteria.The model should improve the accuracy of simulations of occupancy. 展开更多
关键词 EVENT OCCUPANCY urban residential building SIMULATION cold areas of China
原文传递
Construction Technology of Warm Mix Asphalt Pavement in Cold High-Altitude Areas
11
作者 Guangxi Wu 《Journal of Architectural Research and Development》 2023年第5期27-33,共7页
With the continuous development of domestic highway construction,highway civil engineering and service level quality have attracted much attention.Good pavement quality and high-quality service make people feel comfor... With the continuous development of domestic highway construction,highway civil engineering and service level quality have attracted much attention.Good pavement quality and high-quality service make people feel comfortable and smooth when traveling.High-quality pavement can significantly reduce the probability of traffic accidents.At present,there is a direct relationship between pavement quality and pavement construction operations.Carrying out pavement construction operations in cold high-altitude areas requires a reasonable selection of construction equipment and methods.The application of warm-mix asphalt pavement construction technology can ensure pavement quality.Therefore,this paper analyzes the advantages of warm-mix technology,the environmental characteristics of cold high-altitude areas,and construction preparations,and discusses the construction technology of warm-mix asphalt pavement in cold high-altitude areas in detail,to improve the overall road quality of cold high-altitude areas. 展开更多
关键词 cold high-altitude areas Warm mix asphalt Pavement construction technology
下载PDF
Effects of cold climate on growth and development
12
作者 Chun Xing Yidong Wang Yongchen Wang 《Frigid Zone Medicine》 2023年第2期77-82,共6页
Climate is one of the environmental conditions on which people live.Climate conditions impact every aspect of people's daily life and production activities,even the survival of humankind.In recent years,human acti... Climate is one of the environmental conditions on which people live.Climate conditions impact every aspect of people's daily life and production activities,even the survival of humankind.In recent years,human activities have adversely changed the climate.The emergence of global warming and extreme weather has prompted people to pay attention to the impact of climate on life.The adverse climate issues include reduced quality of air and food,facilitated spread of diseases and increased mortality of the population.Being more orientated to climate changes in the past,research has been less alerted to the negative impacts that climate changes could bring to human health.This could be ascribed to that after living in a region for a long time,the human body has"adapted"to climate.And after adaptation,routine health outcomes such as disease incidence and hospitalization rate become less obvious,making the habitants blind from the undesirable impacts of climate on the health status.This review article summarizes the impacts of cold climate on human development,including maternal/fetal factors,lifestyle factors,etc.,and delineates the relationship between cold climate and human health. 展开更多
关键词 cold areas human development climate and health
下载PDF
Settlement Control Technology of High Filled Soil-Rock Embankment in Alpine and High-Altitude Areas
13
作者 Guangxi Wu 《Journal of World Architecture》 2023年第4期75-81,共7页
China's infrastructure has gradually achieved large-scale development,and transportation construction has also shifted from east to west,transitioning from plains to mountainous areas.High-fill embankments of diff... China's infrastructure has gradually achieved large-scale development,and transportation construction has also shifted from east to west,transitioning from plains to mountainous areas.High-fill embankments of different sizes in mountainous areas are unavoidable,and the settlement of high-fill embankments is usually the most concerned issue in high-fill projects.According to the current research of highway projects,most of the high embankments in mountainous areas are soil-rock mixed embankments or rock-filled embankments,and their post-construction settlements are directly related to construction technology and the type of filler used.In this paper,the problems in the settlement control of earth-filled embankment and related factors are analyzed in detail.The settlement control technology of high-fill embankment in high-cold and high-altitude areas is also discussed,so as to ensure the overall quality of high-fill embankment. 展开更多
关键词 High-altitude and cold areas High soil-rock embankment Settlement control technology
下载PDF
TOOTH CURVES AND ENTIRE CONTACT AREA IN PROCESS OF SPLINE COLD ROLLING 被引量:7
14
作者 ZHANG Dawei LI Yongtang FU Jianhua 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2008年第6期94-97,共4页
In spline rolling process, the contact area between roller and workpiece plays an important role in calculating rolling-force and rolling-moment. For the purpose of studying the contact area, contact state between rol... In spline rolling process, the contact area between roller and workpiece plays an important role in calculating rolling-force and rolling-moment. For the purpose of studying the contact area, contact state between roller and workpiece in process of spline cold rolling based upon cross rolling is analyzed. According to the suitable hypothesis, the mathematic model of roller-tooth-curve in optional position of rolling process is established. Combing the theory of conjugate curves with the theory of envelope curve, the corresponding mathematic model of workpiece-tooth-curve is established. By utilizing establishing mathematic models, the algorithm of entire contact area in rolling process is created. On the basis of the algorithm, calculation-program is compiled under MATLAB program language environment. The calculation-program actualizes quantitative analysis and quantitative calculation of contact areas. Utilizing the calculation-program, the influence of parameters on contact area is analyzed, and the tendency is consistent with the manufacturing experience. In consideration of rolling-force optimization, the primary process parameters may be selected according to results of calculation. The result of the present study may provide basis for research on rolling-force and rolling-moment. 展开更多
关键词 SPLINE cold rolling Contact area Mathematic model MATLAB
下载PDF
Study on the Improvement Strategies of Physical Environment for Square in Severe Cold Regions' Rural Areas 被引量:1
15
作者 Xin-Yu Zhang Hong Jin 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2014年第4期18-23,共6页
To improve the comfortable physical environment for square in severe cold regions' rural areas. This paper applies the methods of questionnaires,field testing and statistical analysis to compare and analyze two di... To improve the comfortable physical environment for square in severe cold regions' rural areas. This paper applies the methods of questionnaires,field testing and statistical analysis to compare and analyze two different square cases of Qingyunpu in Liaoning Province,and conclude the main factors which affect the physical environmental comfort. The improvement strategies for physical environment of rural square are put forward from the aspects of site selection,road position,orientation,landscape design,and ground pavement material selection,aiming to provide the design basis for the physical environment of square in severe cold regions' rural areas. 展开更多
关键词 rural areas of severe cold regions SQUARES physical environment improvement strategies
下载PDF
Research on the Development of Green Building Technology in Hot Summer and Cold Winter Area under the Background of Carbon Neutrality:A Case Study of Zhuzhou City
16
作者 Chen Haiyan Liu Shuange +2 位作者 Zhou Hao Chen Zhengsheng Liu Jianlong 《Journal of Energy and Power Engineering》 2022年第4期166-174,共9页
Carbon sequestration and emission reduction in the construction industry plays an important role in China’s goal of achieving carbon neutrality.Research in Zhuzhou city scored 42 since the assessment of the green bui... Carbon sequestration and emission reduction in the construction industry plays an important role in China’s goal of achieving carbon neutrality.Research in Zhuzhou city scored 42 since the assessment of the green building project situation as the research object,in hot summer and cold winter areas of analysis and evaluation on the development of green building technology,and then sums up the carbon neutral background the priority areas and tasks for the development of green building techniques,optimization of the construction industry into a new era under the background of green development to provide the reference. 展开更多
关键词 Carbon neutrality hot summer and cold winter area green building technology
下载PDF
不同土壤条件下秸秆还田量对土壤还原性物质及水稻生长的影响 被引量:1
17
作者 彭显龙 董强 +4 位作者 张辰 李鹏飞 李博琳 刘智蕾 于彩莲 《中国水稻科学》 CAS CSCD 北大核心 2024年第2期198-210,共13页
[目的]在不同土壤上研究水稻秸秆还田后还原性物质的形成及其与水稻生长的关系。[方法]在砂壤土(S1)和粉壤土(S2)上进行2年盆栽试验,模拟低(RL)中(RM)高(RH)产量下秸秆全量还田,以秸秆不还田(R0)为对照,测定土壤还原性物质总量、Eh、亚... [目的]在不同土壤上研究水稻秸秆还田后还原性物质的形成及其与水稻生长的关系。[方法]在砂壤土(S1)和粉壤土(S2)上进行2年盆栽试验,模拟低(RL)中(RM)高(RH)产量下秸秆全量还田,以秸秆不还田(R0)为对照,测定土壤还原性物质总量、Eh、亚铁离子、锰离子和铵态氮含量,分析水稻分蘖、根系干质量、根系活力和水稻产量等指标。[结果]秸秆还田后生育前期土壤Eh显著降低,还原性物质数量增加,S2的还原性物质高于砂壤土。与对照相比,2021年在移栽后56d之前秸秆还田处理还原性物质总量、铁和锰离子含量分别提高了8.36%~199.64%、1.43%~160.03%和8.43%~57.68%。2022年在移栽后45 d前对应增加了2.95%~163.61%、0.77%~19.74%和3.28%~64.96%。随着秸秆还田量增加,还原性物质总量、铁和锰含量有增加趋势。在移栽后56 d前(2021年)和35 d前(2022年)秸秆还田显著增加了土壤铵态氮含量11.28%~50.67%和10.79%~351.53%。秸秆还田使水稻分蘖期和拔节期的根系干质量降低15.06%~45.80%,秸秆还田显著降低了砂壤土上水稻分蘖期和拔节期的根系活力,在S2土壤上RL和RM增加了拔节期根系活力,RH降低了根系活力。秸秆还田后水稻分蘖数在水稻生育期降低了7.23%~48.44%,干物质积累量降低了3.59%~43.57%。RL和RM处理第二年水稻产量降低不明显,RH处理2年均显著减产。砂壤土中氧化还原电位高于S2,S2还原性物质总量、锰离子含量、铵态氮含量、根系干质量、根系活力、分蘖数、干物质积累量和产量均高于砂壤土。[结论]在本研究条件下,秸秆还田显著增加还原性物质总量,抑制水稻早期生长。黏重土壤上秸秆全量还田引起减产,砂壤土上中低产量下秸秆全量还田不会造成穗数显著降低,因促进大穗形成不会造成显著减产。采取有效措施减少秸秆还田下还原性物质危害是秸秆还田技术优化的重点。 展开更多
关键词 秸秆还田 寒地 水稻 还原性物质 产量
下载PDF
Annual variation in Calanus sinicus abundance and population structure in the northern boundary area of the Yellow Sea Cold Water Mass 被引量:2
18
作者 尹洁慧 张光涛 +2 位作者 赵增霞 王世伟 万艾勇 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2013年第6期1284-1294,共11页
The Yellow Sea Cold Water Mass(YSCWM) was suggested as an over-summering site of the dominant copepod species Calanus sinicus in coastal Chinese seas.Population abundance and structure were investigated by monthly sam... The Yellow Sea Cold Water Mass(YSCWM) was suggested as an over-summering site of the dominant copepod species Calanus sinicus in coastal Chinese seas.Population abundance and structure were investigated by monthly sampling along three transects across the northern boundary of the YSCWM during 2009–2010.Results show that thermal stratification existed from June to October and that the vertical thermal difference increased with depth.Generally,total abundance was lowest in October and highest in June,and the female/male sex ratio was highest in February and lowest in August.Evident spatial differences in abundance were observed during the existence of the YSCWM.In June,total abundance averaged 158.8 ind/m3at well-stratified stations,and 532.1 ind/m3at other stations.Similarly,high abundances of 322.0 and 324.4 ind/m3were recorded from July to August inside the YSCWM,while the abundance decreased from 50.4 to 1.9 ind/m3outside the water mass.C.sinicus distribution tended to even out over the study area in September when the YSCWM disappeared.We believe that the YSCWM may retard population recruitment in spring and preserve abundant cohorts in summer.The summer population was transported to neritic waters in autumn.In addition to low temperatures,stable vertical structure was also an essential condition for preservation of the summer population.C.sinicus can survive the summer in marginal areas in high abundance,but the population structure is completely different in terms of C5 proportion and sex ratio. 展开更多
关键词 中华哲水蚤 黄海冷水团 种群结构 丰度 周年变化 边界 垂直结构 人口结构
下载PDF
严寒地区空气源热泵耦合电磁能系统模拟运行研究
19
作者 冯国会 贾敏 +2 位作者 张磊 李旭林 赫娜 《沈阳建筑大学学报(自然科学版)》 CAS 北大核心 2024年第2期322-329,共8页
目的 为了促进空气源热泵耦合电磁能供热系统在严寒地区住宅建筑中的应用,研究该系统的运行性能和稳定性。方法 以沈阳地区某住宅建筑为例,应用Trnsys软件建立了空气源热泵耦合电磁能供热系统仿真模型,并用实测值对模型进行了验证;深入... 目的 为了促进空气源热泵耦合电磁能供热系统在严寒地区住宅建筑中的应用,研究该系统的运行性能和稳定性。方法 以沈阳地区某住宅建筑为例,应用Trnsys软件建立了空气源热泵耦合电磁能供热系统仿真模型,并用实测值对模型进行了验证;深入探讨空气源热泵耦合电磁能供热系统在供热期的运行特点,并与空气源热泵和电磁能供热系统分别进行比较。结果 空气源热泵耦合电磁能供热系统模型可靠,相对误差可以控制在15%以内;在供热期,室内平均温度可保持在17.97~21.84℃;空气源热泵耦合电磁能供热系统比电磁能供热系统的COP提高了59.17%,空气源热泵耦合电磁能供热系统CO_(2)减排量比空气源热泵和电磁能供热系统分别提高1.47%和59.50%。结论 空气源热泵耦合电磁能供热系统运行和COP变化更为稳定,系统环境效益更佳,室内热舒适性更高。 展开更多
关键词 空气源热泵 电磁能系统 COP 严寒地区 耦合系统
下载PDF
种植方式对寒地水稻抗倒伏性状的影响
20
作者 张喜娟 王文龙 +11 位作者 孟英 唐傲 董文军 刘猷红 徐英哲 王立志 姜树坤 杨贤莉 刘凯 姜辉 任洋 来永才 《中国农学通报》 2024年第3期16-25,共10页
为了探索不同种植方式对寒地水稻抗倒伏能力的影响,以‘龙粳21’和‘龙稻18’为试材,比较研究了水直播、旱直播和插秧栽培模式下水稻的抗倒伏特性。种植方式对寒地水稻的抗倒伏特性有显著影响,但两品种表现不一致。其中,‘龙粳21’N1至N... 为了探索不同种植方式对寒地水稻抗倒伏能力的影响,以‘龙粳21’和‘龙稻18’为试材,比较研究了水直播、旱直播和插秧栽培模式下水稻的抗倒伏特性。种植方式对寒地水稻的抗倒伏特性有显著影响,但两品种表现不一致。其中,‘龙粳21’N1至N4节间的倒伏指数为插秧>水直播>旱直播,单茎抗推力为旱直播>插秧>水直播。‘龙稻18’N1、N3和N4节间的倒伏指数为插秧>旱直播>水直播,N2节间为旱直播>插秧>水直播,单茎抗推力均为水直播>插秧>旱直播。相关分析表明,提高寒地水稻抗倒伏能力应适当降低株高、重心高度和N1、N2节间的长度,不宜攻大穗。在寒地稻区,通过选择适宜的品种及合理地构建多穗和小穗的群体结构,既利于直播稻获得较高的产量,也有利于提高抗倒伏性。 展开更多
关键词 寒地 水稻 种植方式 倒伏指数 单茎抗推力
下载PDF
上一页 1 2 118 下一页 到第
使用帮助 返回顶部