首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 140 毫秒
1.
以 6-甲氧基 - 8-氨基喹啉为原料 ,经重氮化后与间苯二酚偶联 ,合成了有机试剂 4- (6-甲氧基 - 8-喹啉偶氮 ) -间苯二酚 (简称 MQAR) ,用 DMF重结晶精制。通过TL C、EA、UV- VIS、IR、1 HNMR等分析手段 ,对合成产物进行分析和结构鉴定 ,确证得到了 MQAR纯品 ,产品熔点为 1 94℃。  相似文献   

2.
基于建立的需求-排放-成本模型,结合情景分析,评估海南省房间空调行业温室气体协同减排潜力与成本。研究表明,海南省房间空调器行业在氢氟碳化物(HFCs)制冷剂转型的同时推进能效提升,既可大幅度减少直接和间接排放,实现房间空调制冷剂近零排放,同时通过节电获得相对收益。在基加利修正案能效情景与加速转型能效情景中,2021—2060年海南省房间空调器行业可分别累计减排50~62MtCO2-eq和77~94MtCO2-eq,直接减排量占比分别约为30%和55%,平均减排成本分别为-219.3~-219.1元/t和-115.6~-112.8元/t。  相似文献   

3.
以2012年六盘水市烤烟种植面积、产生的经济效益为指标,采用中国气象局颁布的《高炮人工防雹增雨作业业务规范》中的火箭人工增雨作业影响区范围、人工催化后最大增雨量及有效增雨量、直接经济效益估算法作为人工增雨效果评价的方法,并以2012年5月9日和6月6日共两次人工增雨作业为例,进行实际计算。结果表明:两次人工增雨作业,共取得7 140万元最大经济效益,672万元的有效经济效益,增加有效水量约为0.224亿t,最大限度地缓解了主要烟区的旱情,为六盘水市烤烟生产提供了良好的条件,烤烟种植面积8 764.93 hm2,收购烟叶29.75万担,上等烟比例为44.93%,中等以上烟叶比例为92.07%,取得总产值2.99亿元的经济效益。所采用的评价方法,简单易懂,适宜基层气象部门做好人工增雨的专业气象服务效益评估。  相似文献   

4.
根据1961—2009年新疆博州4个国家基本气象站的日最低气温资料,用气候趋势系数t、检验研究了终霜冻、初霜冻和无霜冻期的特征、长期变化趋势及突变时间。结果表明:除阿拉山口外,博州自东向西随地势的由低到高终霜冻逐渐推迟,初霜冻逐渐提前,无霜冻期逐渐缩短。终霜冻除温泉为微弱的推迟趋势外,其他地区均呈提前趋势,但不显著;初霜冻以2.5~4.2 d/10 a的显著趋势推迟;无霜冻期以2.2~4.8 d/10 a的速率延长,除温泉外均为显著趋势。  相似文献   

5.
云中闪电及云下部正电荷的初步分析   总被引:10,自引:10,他引:10  
1986年夏季,我们在兰州中川机场附近对雷暴过程中的闪电进行了3站电场、电场变化及声光差的同步观测。本文定量分析了8月3日和4日两次雷暴过程中的7个云闪放电。结果表明,除一个为云中负电荷区和其上部正电荷区之间的放电外,其余都是负电荷区和云下部范围很大的正电荷区之间的放电。放电中心在海拔高度为3.8—6km之间(对应环境温度为7.6—-13.5℃),中和电矩约18—48Ckm。云下部的这种放电现象在文献中还很少见报道。  相似文献   

6.
了解涂装行业挥发性有机物(VOCs)的排放特征是制定山东地区臭氧(O3)和PM2.5防控策略的重要环节.本研究在山东地区测定了两家典型食品金属包装企业喷涂过程中VOCs的排放组成,企业产品以饮料罐和罐头为主.结果表明:两家企业排放的总VOCs质量浓度水平相当,质量浓度变化范围在50~1 500 μg/m3;但两家企业喷涂过程中VOCs的排放组成具有一定的差异,以生产铝罐和马口铁罐为主的企业中的含氧挥发性有机物(OVOCs)含量最多,占比89.71%(质量分数,下同);而生产铝罐的企业芳香烃(56.15%)是首要的排放种类,其次是OVOCs (32.32%).通过分析两家企业内外喷涂工艺的VOCs源成分谱,发现同一企业不同工艺之间有一定差异,多种罐生产企业的内、外喷涂中乙醇占比最高,分别为94.28%、84.46%;单铝罐生产企业的内喷涂2-丁酮(24.33%)是重要组分,外喷涂中甲苯(36.40%)含量较高.  相似文献   

7.
为保障饮用水源地闹德海水库的水质安全,通过选取不同氮磷允许负荷量的测算模式进行综合分析。结果表明:闹德海水库实际负荷量总氮为139.98 t/a、总磷为28.28 t/a,目前已处于中—富营养化状态;水库若要达到贫—中营养化状态,应削减总氮129.96 t/a,总磷27.27 t/a。为此,从发展农业节水、综合防治化肥、农药、畜禽养殖业污染及治理水土流失等方面提出了科学的污染防治思路及削减对策。  相似文献   

8.
基于水生态文明建设的要求,二连浩特市供水(改扩建)工程净水厂选取了3种氟化物去除工艺,并进行技术比较分析。结果表明:3种降氟处理工艺均能满足现行国家标准《生活饮用水卫生标准》(GB5749-2006)的规定;采用方案一,活性氧化铝除氟、吸附、再生都是在吸附滤池中进行的,容易自动化控制,而且土木工程建投资少,并且具有处理水量大、效果运行可靠、成本低廉、管理简便、一专多能的特点,其余两个方案作为参考。  相似文献   

9.
农业气象观测的最优化问题是一个综合性的问题。在解决这个问题时,必须考虑观测目的、天气气候变化和农业对象的地区性与统计结构。它本身包括以下几个问题:确定农业气象观测的允许误差;评定气象要素的时空变化;解决气象观测合理的时空分布。一般来说,农业生产过程可以表达为(dД)/(dt)=f(M_t,W_t,R_t) (1)Д——由 t 时刻前的环境条件所决定的最高产量(潜在产量),它等于Д=integral from t to t_0 f(M_t,W_t,R_t)dt (2)M_t,W_t——在 t 时刻的农业对象和环境状况;R_t——在同一时刻农业措施的影响;t_0——t的初始时刻。  相似文献   

10.
利用德州2008年1-12月逐日气温(t150表示)与70cm温度(t70表示)资料分析得出:08时,1、2、12月,t70≤t150;3-11月,t70>t150。14时,全年t70>t150;20时,全年t70相似文献   

11.
周万福  牛生杰 《气象科学》2006,26(5):509-516
由高斯烟羽模式推导出的标准浓度分布推算源强分布的反演模式方法,计算了西宁市北郊地区环境空气中氟化物的环境容量。计算结果表明:拟建或已经在生产的各铝厂氟化物排放量均不超过按城市标准计算出的环境容量值,但均超过按农业区标准计算出的环境容量值。为了保护该地区农业生态环境,需要对现有的各铝厂氟化物排放量进行削减。  相似文献   

12.
为了研究一种新的环保型消暖雾催化剂RC/XW的消雾性能,同时选取无水氯化钙(CaCl2)和氯化钠(NaCl)2种吸湿性物质作为对比物,对它们进行室内试验研究。其中RC/XW粒子直径主要集中在12um;将无水氯化钙和氯化钠分别粉碎成10um、15um、20um和30um4个不同的直径。结果表明:不同种类的催化剂、同种类不同尺度的催化剂之间消雾效果都存在很大差异。消雾效果与播撒剂量直接相关。RC/XW适用于消除含水量在0.3g·m^-3以上的严重影响视程的暖雾,且播撒剂量要〉1g·m^-3。  相似文献   

13.
高平市地质灾害与气象条件的浅析   总被引:1,自引:0,他引:1       下载免费PDF全文
利用高平市地质灾害资料和降水资料,分析了地质灾害发生的时空分布特征,探讨了地质灾害发生发展的规律,得出:高平市境内的地质灾害种类不同,其地理分布不同,产生的天气背景也不同,掌握规律,做好天气预报,为减少灾害提供科学的依据。  相似文献   

14.
In this work, the X-ray Photoelectron Spectroscopy (XPS) technique is utilized to analyze the surface chemical composition of particulate matter (PM) which was collected from various locations at Jeddah, Saudi Arabia. The main elements found on the surface of PM are carbon (C), oxygen (O) and silicon (Si) with combined percentage of 89.4–94.9 while traces of nitrogen (N), calcium (Ca), aluminum (Al), sodium (Na), chlorine (Cl), manganese (Mg), and sulfur (S) were also present. The analyzed XPS chemical state of C, O and Si was further used to determine their bonding with other elements occurring over the surface of PM. Carbon was found in the form of carbides (18.86%), fluorides (2.39%) and carbonates (78.75%); oxygen was observed as oxides (21.05%) and hydroxides (73.42%) of other metals; and silicon was detected as silicones (12.16%), nitrides (82.53%) and silicates (5.25%). The particle size of a PM is also of great concern for health issues, and thus has been investigated by the Field Emission Scanning Electron Microscope (FESEM). The Energy Dispersive X-ray Spectroscopy (EDS) was employed for cross verification of detected elements by XPS.  相似文献   

15.
In order to determine if pollutants from the Wollongong-Sydney-Newcastle industrial area in southeastern Australia can be transported northwards, affecting precipitation quality to the north, a preliminary study of fog and rainwater quality was carried out from January to April 1989. Samples were collected from two sites in the state of New South Wales, one in the Barrington Tops and the other near Dorrigo. These samples were analyzed for the cations sodium, calcium, magnesium, potassium, and ammonium, and the anions chloride, nitrate, sulfate, methanesulfonate, formate and acetate, as well as pH and conductivity.The mean pH of fogwater from the two sites was 5.48, compared to 5.62 for rainwater. Fogwater also had concentrations of ions 2–6 times those in rainwater. For both fog and rain the ions sodium, chloride, magnesium, and methanesulfonate at both sites were essentially entirely sea-salt derived, while only 5–50% of potassium, calcium, and sulfate were derived from sea-salt. The acid-base balance was adequately described (r=0.76) by a balance between the acidity contributed by sulfuric and nitric acids, neutralized by the alkalinity of ammonia and (soil dust-derived) calcium carbonate. Comparing this study with others, both within Australia and overseas, fog and rainwater at both sites are not polluted, with acidity only slightly greater than background and concentrations of anthropogenic pollutants very low, and with sea-salt influences accounting for the majority of ionic loading.  相似文献   

16.
简单介绍了由多普勒天气雷达径向风资料反演平均散度和径向散度的计算方法,以2004年7月11—12日暴雨过程为例说明两种散度在迎风坡暴雨跟踪、预报中的综合应用。分析结果表明:①平均散度可以作为降水跟踪、预测的背景场。降水出现之前,低层平均散度存在辐合;低层辐合加强或维持,整个区域降水将加强;辐合高度抬升到中层并维持,降水达到最强;辐合减弱并开始出现辐散,区域降水将逐渐结束。②根据径向散度的分布情况,可以提前2 h以上预报强降水的落区。强降水落在径向辐合大值区后部的较弱辐合区内,且弱辐合区强度越强,未来降水强度越大。因此,综合分析平均散度和径向散度随时间的变化,可以跟踪、预测降水的发展演变,特别是可以给出暴雨的大致落区。  相似文献   

17.
在智能网格气象预报产品的基础上,采用B/S+C/S混合架构,建立了"环广西"赛道气象服务产品共享平台。通过共享平台,快速完成精细化气象服务产品的制作和发布,为做好重大活动气象服务保障提供借鉴和参考。  相似文献   

18.
The foundations of modern society are based on metals, yet their production is currently placing considerable strain on the Earth’s carrying capacity. Here, we develop a century-long scenario for six major metals (iron, aluminum, copper, zinc, lead, and nickel) harmonized with climate goals, with the goal of establishing science-based targets. We show that for the metal sector to contribute proportionally to emission reductions targets of the industrial sector, global in-use metal stocks need to converge from the current level of around 4 t/capita to about 7 t/capita. This will require today’s high-income countries to contract their per capita stock from current levels of about 12 t/capita to make room for growth in countries that are presently classified as middle- and low-income countries. In such a contraction and convergence scenario, primary production of all six metals will peak by 2030, and secondary production will surpass primary production by at least 2050. Consequently, cumulative ore requirements over the 21st century will remain below currently identified resources, implying that natural ore extraction will be limited by emissions budgets before existing resources can be depleted. Importantly, realizing such system changes will require urgent and concerted international efforts involving all countries, but specific responsibilities will vary according to income level. Namely, wealthy countries will need to use existing metal stocks more intensively and for longer periods to reduce stock replacement demand, while poor countries will need to develop long-lasting and material-efficient infrastructure to curtail stock expansion demand in the first half of the 21st century.  相似文献   

19.
International regulations are under consideration for methyl bromide because of its high time dependent ozone depletion potential. Geocycling of the species is not well understood, and removal may occur in several types of natural water incuding the oceanic and those in soils. The hydrolysis reaction is a dominant loss pathway in environmental aqueous systems, but rate constants have generally been reported only in distilled water and at greater than room temperature. Here we present measurements in sodium chloride solutions and in seawater in addition to pure water, and at temperatures across the oceanographic range. The reaction could be followed even in solutions near the freezing point because product methanol was monitored in the method of initial rates. Time constants for methyl bromide hydrolysis fall between 10 and 1000 days over the temperatures of the sea, and are always within an order of magnitude of the fastest abiotic destruction mode, chlorination. Activation energies for the two processes are similar so that the ratio of their time scales does not vary with oceanic location. Hydrolysis rate constants are also listed for the closely related compounds methyls iodide and chloride. Solvolysis of the methyl halides in natural waters acts as a source of methanol to the ocean and atmosphere.  相似文献   

20.
The reaction coefficients of nitrogen dioxide and nitrous acid with monodisperse sodium chloride and ammonium sulphate aerosols have been measured in a flow reactor at atmospheric pressure. These experiments were performed at relative humidities above and below the deliquescence points of both aerosols (r.h. 50 and 85%) at 279 K. The results for NO2 afford a reaction coefficient in the range (2.8–10) × 10-4 and for HONO, (2.8–4.6) × 10-3. For both species, there appears to be an enhancement of the reaction coefficient on sodium chloride aerosol at 50% r.h. The results are compared with reaction coefficients determined by other experimental methods. A good agreement is found for both gases between this method and the coated denuder method previously developed in our research laboratories (Msibi et al., 1993) and with the majority of other published data for NO2. In the case of HONO, our estimate of reaction coefficient is smaller than, or at the lower limits of the ranges reported by other published studies.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号