Responses of chlorophyll fluorescence and nitrogen level of Leymus chinensis seedling to changes of soil moisture and temperature

Controlled experiment of Leymus chinensis seedlings grown in the environmental growth chambers at 3 soil moisture levels and 3 temperature levels was conducted in order to improve the understanding how leaf photosynthetic parameters will respond to climatic change. The results indicated that soil drought and high temperature decreased the photochemical efficiency of photosystem ( Fw/Fm ), the overall photochemical quantum yield of PSIl(yield), the coefficient of photochemical fluorescence quenching(qp), but increased the coefficient of non-photochemical fluorescence quenching( q, ). Severe soil drought would decrease Fv/Fm and yield by 3.12% and 37.04% under 26% condition, respectively, and 6.60% and 73.33% under 32% condition, respectively,suggesting that higher temperature may enhance the negative effects of soil drought. All the soil drought treatments resulted in the decline in leaf nitrogen content. There was no significant effect of temperature on leaf nitrogen level,but higher temperature significantly reduced the root nitrogen content and the ratio of root nitrogen to leaf nitrogen,indicating the different strategies of adaptation to soil drought and temperature. It was also implied that higher temperature would enhance the effect of soil drought on leaf photosynthetic capacity, decrease the adaptability of Leymus chinensis to drought.     

Effects of traffic pollution on the genetic structure of Poa annua L. populations

The genetic composition of Poa annua L, populations with a series of traffic pollution was studied by starch electrophoresis. Five enzyme systems were stained. The results showed that: (1) Traffic pollution can dramatically change genotypic frequencies at some loci of P. annua populations. Significant deviations from HardyWeinberg equilibrium were observed on loci Fe - 1 and Me due to the excess of heterozygotes in some populations.(2) The effective number of alleles per locus and the observed and expected heterozygosity were higher in the pollution series than in the clear control site(Botanic Park population), but the increase was not related with the pollution extent. (3) Most genetic variation was found within populations, and only 6.21% was among populations of the polluted series. Slightly higher differentiation( FST = 7.98%) was observed when the control population was included. (4) The calculated gene flow(Nm) is 2.8841 per generation. The mean of genetic identity is 0.9864 and the genetic distance average to 0.0138.     

做职业健康管理工程师

“一个大型国有企业的三级甲等医院,拿出相当一部分力量从事职业健康技术服务工作,是由我们医院的发展定位所决定的。”中国石油中心医院院长兼中国石油集团石油职业卫生技术服务中心主任姜杉教授在接受记者采访时开门见山地说,“我们中心作为中国石油的职业病防治机构,列入中国石油中心医院的序列,业务上接受中国石油安全环保部指导。     

中国人力资源市场信息监测中心发布2010年第三季度部分城市公共就业服务机构市场供求状况分析（下）

五、进入市场求职的人员中,失业人员和外来务工人员是主体;与上季度和去年同期相比,新成长失业青年、外埠人员均有较大幅度增长。     

宁波：1794个服务室让求职更便捷

近年来,浙江省宁波市高度重视城乡统筹就业工作,把公共就业服务均等化作为统筹城乡发展的主要任务来抓,在全市建立起了市、县（市）区、街道（乡镇）、社区（村）四级公共就业服务网络。到去年底,全市62个街道、90个乡镇、456个社区全部建立了基层劳动保障服务站（室）,2612个行政村中有1794个建立了劳动保障服务室,并且绝大部分与各级公共职业介绍机构联网,实现了就业信息资源的共享。无论是农民还是城镇居民,     

"启迪注册安全工程师事务所"在京成立

"北京启迪注册安全工程师事务所",即北京启迪注安技术服务有限公司,是北京市工商局正式注册的安全工程师事务所性质的专业中介服务机构。"启迪注安事务所"的成立是启迪中心多年来从事企业职     

服务区域经济发展 维护国家南海主权——北部湾海事联合巡航执法之我见

广西背靠大西南,南濒北部湾,东邻粤港澳．面向东南亚,具有“承东启西、连接东盟”的巨大区位优势。随着国家深入实施西部大开发战略和中央批准实施《广西北部湾经济区发展规划》．自治区党委、政府按照中央给广西北部湾经济区“充分发挥连接多区域的重要通道、交流桥梁和合作平台作用”的功能定位要求,广西北部湾风生水起,     

中间站调车作业安全的探讨

文章从中间站调车事故发生的概率情况分析入手,剖析了中间站调车作业中存在的问题,提出了调车作业安全的针对性措施,建议通过综合治理,最大限度消除隐患,确保中间站调车作业的安全。     

扬中市采取有力措施强化企业主体责任落实

本刊讯 连云区安监局把服务经济社会发展作为安全监管工作的根本出发点和落脚点,寓监管于服务之中,想方设法为企业生产服务,努力实现安全监管与企业发展共赢。为此,对连云港中彩多晶硅有限公司、赛孚燃油等重点建设项目,明确专人跟踪服务,及时了解和发现项目建设中存在有关安全生产问题,并主动帮助企业解决。     

南通市通州区工伤保险浮动费率7月起正式实行

连云港市审批中心安监窗口严格遵循高效便民的行政审批原则,始终把办事群众满意度作为工作的出发点和落脚点,切实落实审批提质加速的各项要求。通过强化告知承诺制,深化行政公开举措,推行“延时服务、限时服务、预约服务、便捷服务、重点服务”等个性化服务,积极加入重大项目服务绿色通道建设,进一步创新简化审批程序,全力提高办事效能。