期刊文献+
共找到5篇文章
< 1 >
每页显示 20 50 100
徐水区耕地质量制约因素以及对策分析
1
作者 杜艳芹 《农家致富顾问》 2021年第10期253-253,共1页
耕地质量是影响农业发展的重要因素,对于农业发展而言有非常重要的作用。本文主要针对徐水区耕地质量现状进行分析,主要阐述徐水区耕地现状以及制约因素,同时针对徐水区耕地质量制约因素提出解决问题的意见对策,对于徐水地区的农业发展... 耕地质量是影响农业发展的重要因素,对于农业发展而言有非常重要的作用。本文主要针对徐水区耕地质量现状进行分析,主要阐述徐水区耕地现状以及制约因素,同时针对徐水区耕地质量制约因素提出解决问题的意见对策,对于徐水地区的农业发展有非常重要的作用。 展开更多
关键词 徐水区 耕地质量 制约因素
原文传递
徐水区玉米肥效田间试验研究
2
作者 杜艳芹 《农家致富顾问》 2021年第8期113-113,共1页
近些年,随着农业产业结构的调整力度不断加大,如何提升单位面积内玉米的产量和品质,成为科技工作者需要重点攻克的难题。大量研究结果表明,施肥对玉米产量和品质的提升有着较为明显的影响,为了进一步了解玉米施肥的相关参数,准确掌握化... 近些年,随着农业产业结构的调整力度不断加大,如何提升单位面积内玉米的产量和品质,成为科技工作者需要重点攻克的难题。大量研究结果表明,施肥对玉米产量和品质的提升有着较为明显的影响,为了进一步了解玉米施肥的相关参数,准确掌握化肥的使用情况,实现化肥减量食用增加玉米产量,在保定市徐水区的个种植户中开展玉米施肥田间试验,并对试验数据进行针对性的分析。 展开更多
关键词 徐水区 玉米肥效 田间试验
原文传递
保定启示:区域一体化下教育发展的经验
3
作者 周彩丽 《教育家》 2019年第38期54-56,共3页
京津冀协同发展战略实施以来,保定市抢抓机遇,着力解决保定教育发展水平与京津落差大、办学基础条件和管理水平薄弱等短板问题,积极对外开放,通过观念、管理、资源、开放和服务"五个对接",引入、承接京津优质资源,扩大、完善... 京津冀协同发展战略实施以来,保定市抢抓机遇,着力解决保定教育发展水平与京津落差大、办学基础条件和管理水平薄弱等短板问题,积极对外开放,通过观念、管理、资源、开放和服务"五个对接",引入、承接京津优质资源,扩大、完善优质教育体系,加快优质教育资源共建共享,推动教育均衡发展,提升教育整体水平。京津冀协同下,保定教育实现跨越式发展。保定教育对接京津,取得成功的因素是什么?我们能从中获得哪些启示? 展开更多
关键词 保定市 幼儿园 阜平县 名校长 徐水区 集团化办学 京津冀协同 优质校 区域一体化 理念引领
下载PDF
Application of HEMS cooling technology in deep mine heat hazard control 被引量:46
4
作者 HE Man-chao 《Mining Science and Technology》 EI CAS 2009年第3期269-275,共7页
This paper mainly deals with the present situation, characteristics, and countermeasures of cooling in deep mines.Given existing problems in coal mines, a HEMS cooling technology is proposed and has been successfully ... This paper mainly deals with the present situation, characteristics, and countermeasures of cooling in deep mines.Given existing problems in coal mines, a HEMS cooling technology is proposed and has been successfully applied in some mines.Because of long-term exploitation, shallow buried coal seams have become exhausted and most coal mines have had to exploit deep buried coal seams.With the increase in mining depth, the temperature of the surrounding rock also increases, resulting in ever increasing risks of heat hazard during mining operations.At present, coal mines in China can be divided into three groups, i.e., normal temperature mines, middle-to-high temperature mines and high temperature mines, based on our investigation into high temperature coal mines in four provinces and on in-situ studies of several typical mines.The principle of HEMS is to extract cold energy from mine water inrush.Based on the characteristics of strata temperature field and on differences in the amounts of mine water inrush in the Xuzhou mining area, we proposed three models for controlling heat hazard in deep mines:1) the Jiahe model with a moderate source of cold energy;2) the Sanhejian model with a shortage of source of cold energy and a geothermal anomaly and 3) the Zhangshuanglou model with plenty of source of cold energy.The cooling process of HEMS applied in deep coal mine are as follows:1) extract cold energy from mine water inrush to cool working faces;2) use the heat extracted by HEMS to supply heat to buildings and bath water to replace the use of a boiler, a useful energy saving and environmental protection measure.HEMS has been applied in the Jiahe and Sanhejian coal mines in Xuzhou, which enabled the temperature and humidity at the working faces to be well controlled. 展开更多
关键词 deep mine heat hazard mine classification mine water inrush heat hazard control model
下载PDF
Chromium leaching mechanism of coal mine water—a modeling study based on Xuzhou-Datun coal mine district 被引量:5
5
作者 SHAN Yao QIN Yong, WANG Wenfeng School of Resource and Earth Science, China University of Mining & Technology, Xuzhou 221116, China 《Mining Science and Technology》 EI CAS 2010年第1期97-102,共6页
In order to investigate chromium contamination of coal mine water, to analyze chromium leaching mechanism and to evaluate environment pollution potential of coal mine water, we perform site investigations, physical an... In order to investigate chromium contamination of coal mine water, to analyze chromium leaching mechanism and to evaluate environment pollution potential of coal mine water, we perform site investigations, physical and computer modeling in the Xuzhou-Datun coal mine district. The result of our test samples shows that chromium concentration was 9 μg/L in roof leachate and 3 μg/L in coal leachate. The host rock has a higher pollution potential than that of coal seams. Leaching experiments and XRD test results indicate that chromium is released from the process of transforming illite to kaolinite. The pH, pe and temperature of coal mine water affect the chromium leaching behavior. Modeling results suggest that the adsorption of adsorbents controls chromium concentration in coal mine water. The chromium adsorption ratio is quite low in both an acid and in an alkaline environment. Therefore, coal mine water has a high pollution potential. Under other conditions, chromium adsorption is stronger in a neutral water environment, so that chromium concentrations may be very low. 展开更多
关键词 CHROMIUM coal mine water LEACHING
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部