The characteristics of rain electricity in Nigeria. I — Magnitudes and variations

The characteristics of rain and point charges based on routine measurements extending over four rainy seasons are presented. An average rain current density of (1.0±0.1)×10^–10 A m^–2 and charge per unit volume of rain water of (0.43±0.02)×10^–4 C m^–3 for the locality are obtained, which are compared with data obtained elsewhere by other workers. The point-discharge current measurements lead to a revised estimate of (0.86±0.08)×10^–9 A m^–2 for the average point discharge current below storm clouds.     

棉花耗水规律和灌溉随机控制

根据5年田间试验资料,分析了棉花产量与耗水量的抛物线关系,确定了棉花最佳耗水量;根据棉花植株在不同土壤湿度情况下气孔阻力、蒸腾强度和蕾铃脱落率的变化,确定了不同生育阶段的适宜水分指标和干旱指标。在此基础上,研制了棉花灌溉随机控制模型,可以动态预报棉田土壤有效水分含量和实际蒸散量,并从经济效益和水分利用效率的角度提出优化灌溉决策。     

On the relationship between small atmospheric ions concentration and (1) smoke, (2) sulfur dioxide and (3) wind speed

In the present study the influence of smoke and sulfur dioxide concentrations and of wind velocity on the concentration of small positive and negative ions above Athens area (=37°58.3N, =23°43E,h=107 m) is examined.Between the above mentioned elements simple linear correlation and multiple linear correlation is attempted. This correlation is based on mean daily values of the elements, for the two-year period 1971–1972, for each month separately.From the above examination it has been ascertained that small ions concentration increases as smoke and/or sulfur dioxide concentration decreases. Also, small ions concentration increases as wind velocity increases.In addition, it was ascertained that sulfur dioxide contributes the least to the determination of the variance of small ions concentration, whilst the greatest contribution is made by smoke for the positive small ions or by wind velocity for the negative ones.     

Time fluctuations of small ion number density in the atmospheric surface layer

The standard deviations and time-spectra of small ion number density have been measured at ground level under different atmospheric stability conditions. The auto-correlation correlograms and the time-spectra imply a scale of fluctuations corresponding to 1 to 4 min. No clear relationships between standard deviations of small ion number density and micro-meteorological parameters are observed. Thus the results are not a support for Monin-Obukhov similarity theory. For the highest frequencies the slopes of the spectra seem to follow the –5/3-law fairly well and the frequencies of the peak values of individual spectra lnfS(f) increase when the atmosphere stability increases, which is valid for ordinary micrometeorological parameters.     

基于MSP430F135的货车防盗报警系统设计

针对当前铁路运营的实际情况,设计并实现了基于MSP430F13x系列单片机的货车防盗报警系统.详细介绍了系统的原理和软、硬件设计.系统在货车遭遇破封的情况下触发报警器,并将报警信息以无线电信号发射出去.接收机接收报警信息并将其在LCD上显示出来,以便民警即时处理.经实际应用证明系统性能良好.     

温度和盐度对埋栖性双壳类泥蚶(Tegillarca granosa) 呼吸、排泄的影响

在人工条件下采用静水封闭呼吸瓶的方法研究了温度、盐度对泥蚶(Tegillarca granosa)呼 吸、排泄的影响, 并综合分析了温度、盐度交互作用对呼吸、排泄的影响程度, 为泥蚶基础生物学研 究积累了资料。结果表明, 在设定的不同温度条件下泥蚶耗氧率变化范围0.63-4.47mg/(g·h), 单因 素方差分析结果显示4 个盐度条件下泥蚶耗氧率的差异均极显著(P<0.01); 排氨率的变化范围 123.11-955.68μg/(g·h), 排氨率受温度的影响也均极显著(P<0.01); 经回归发现, 在温度13-31℃ 范 围内, 耗氧率和排氨率均与温度的变化呈显著的指数相关。除温度为18℃ 时, 其它各温度条件下, 不同盐度梯度间的耗氧率差异不显著(P>0.05), 盐度对排氨率影响的变化趋势不一致。在温度 (13-31℃)和盐度(18-28)时, 温度和盐度对耗氧率、排氨率的影响均存在交互作用, 耗氧率(Y)、排 氨率(Y)与温度(T)和盐度(S)之间的二元线性回归关系为Y=a+bT+cS+dT×S.泥蚶呼吸排泄的O:N 比 在4.50-13.07 之间, 平均值为7.16.泥蚶呼吸排泄的代谢活动受温度、盐度的影响显著。     

Precious corals become more precious in the northwestern pacific: Urgent need for integrated policy

The limited precious coral (Coralliidae) resources in the Northwestern Pacific have been managed by Taiwan with a comprehensive management plan, by Japan with a strengthened set of management measures, and by China through the listing of such coral as a Category I national treasures. However, continuous increases in coral consumption and coral prices have stimulated overexploitation and poaching of the resource, and hence have undermined the effectiveness of these management schemes. This article discusses the current precious corals supply chain and suggests that the rise of China in purchasing substantial amounts of coral products was the underlying cause for overexploitation and poaching. Several gaps in the management schemes are also identified and discussed. The article finally concludes that there is an urgent need for establishing a cross-disciplinary integrated conservation policy and a regional management platform consisting of the three participating states to address all the relevant social and ecological issues.     

The seafood market in Portugal: Driving forces and consequences

Portugal has the third highest seafood consumption per capita in the world and current patterns of seafood consumption are linked to how seafood products were embodied in the Portuguese society. The objective of this research is to understand Portuguese seafood consumption's main drivers and its consequences. For that official statistics were analyzed and a literature review on seafood consumption was undertaken. Portuguese seafood consumption is characterized by a wide diversity of species and preparing modes, when compared to other countries in Europe. Cod (salted and dried), does not exist in Portuguese waters but due to several factors, such as politics, religion and tradition, became the main species in Portuguese seafood consumption, representing around 38% of the national seafood demand. Five drivers are suggested to explain why Portuguese eat so much seafood: geography, marine resources, fisheries, social forces and politics; and consequences for the environment, economy and health are discussed. Hence while most dietary recommendations advise an increase in fish consumption is not applicable to Portugal and a more sustainable seafood consumption for the future is advocated.     

一种电费管理系统的设计与实现

针对供电部门所辖范围内的用户,开发出一种能完成电费管理、信息管理等功能的综合管理系统.该电费管理系统采用B/S模式(浏览器/服务器模式),面向对象语言Java作为编程开发语言,动态网页采用JSP技术来制作,网络数据库则使用MySQL,同时采用JDBC接口连接MySQL数据库,Tomcat作为Web服务器,集成开发环境选择MyEclipse6.6.该系统可以较大地降低电力部门的管理成本,减轻供电系统日常管理的压力.     

Zn2+对日本沼虾(Macrobrachium nipponensis)的急性致毒效应

在水温(27.4±1.3)℃条件下,以体长(33.23±1.66)mm、体质量(0.7893±0.1518)g的日本沼虾为实验动物,采用静水停食法开展了Zn2+对日本沼虾的急性毒性实验,并以此为基础,测定了Zn2+不同质量浓度水平下日本沼虾的耗氧率与窒息点.结果表明:(1)Zn2+对日本沼虾的急性致死效应与其呼吸生理代谢受阻密切相关;(2) Zn2+对日本沼虾24h、48h、72h、96h的半致死质量浓度依次为1.493、0.844、0.643和0.464mg/L; (3) Zn2+对日本沼虾昼均、夜均和日均耗氧率均无显著影响的阈值为0.046mg/L,该值为Zn2+对日本沼虾急性毒性的安全质量浓度;(4) Zn2+对日本沼虾产生轻度胁迫和中度胁迫的质量浓度范围分别为0.046-0.064mg/L和0.064-0.082mg/L.