Underemployment is a global problem. This study aimed to assess the short- and long-term effects of underemployment (hidden unemployment) on workers’ health, using data from the China Labor-force Dynamic Survey (CLDS) 2016 and 2014. Indicators reflecting workers’ self-rated health, mental health, prevalence of illness over time, and employment status were analyzed using logit regression models, propensity score matching methods, and instrumental variable methods. Empirical analyses showed that: (1) In the short-term, the impact on health is multidimensional, with underemployment significantly associated with a decline in workers’ self-rated health, an increase in the propensity for depression, and an increase in the prevalence of illness over a certain period of time. (2) In the long-term, the experience of underemployment two years in the past is associated with a current decline in workers’ mental health. That is, the negative effects of underemployment on workers’ mental health persist and do not disappear rapidly over time. The results demonstrated that underemployment is detrimental to workers’ health in the short- and long-term. In the context of epidemic prevention and control, the government and society should focus on this expanding group, establish labor protection mechanisms, and reduce the multiple effects of underemployment on workers’ health.

采用2010～2018年海南岛天气分型资料和闪电定位数据,统计分析在南海低压槽影响下海南岛地闪发生概率和地闪频次的时空分布特征.结果显示:4～10月南海低压槽是影响海南岛天数最多的天气分型,产生的地闪频次仅于华南沿海槽,列第二位;南海低压槽影响的月份主要为5～10月份,地闪频次以8月最多,5和10月较少;海南岛地闪发生概率和地闪频次时段分布曲线均呈单峰特征,高值区分布在12:00～21:00时段,15:00～18:00时段为高峰期,在12:00～21:00时段过程中后2 d的地闪发生概率要比过程中前2 d的稍高,但地闪频次要明显低于过程中前2 d;海南岛地闪发生概率月分布曲线呈单峰特征,8月份地闪发生概率最高,5和10月相对较低;海南岛21:00～次日12:00时段地闪发生概率高值区主要分布在东南沿海并随时间逐渐向西北扩展,概率值在5％以下,12:00～21:00时段地闪发生概率高值中心主要分布在昌江、白沙、儋州等海南岛西部市县,15:00～18:00时段概率中心值达40％.

Biases of aerosol simulation by models participating the Aerosol and Chemistry Model Intercomparison Project (AerChemMIP) were identified over China. Although the yearly trend of simulated aerosol optical depth (AOD) agrees with the MODIS satellite retrievals for the country-wide averages, this agreement is an offset between the underestimation of AOD over eastern China and the overestimation of AOD over western China. The AODs were underestimated over the Northeastern China Plain and the North China Plain all year along and overestimated over Sichuan Basin in the winter. These model biases were persistent over multiple years from 2002 to 2015. We attempt to evaluate the impact of emission uncertainties on model simulated aerosol properties and aerosol radiative forcing by comparing the simulations by the Community Earth System Model version 2 (CESM2) with the default inventory developed by the Community Emission Data System (CEDS) and with a country-level inventory (Multi-resolution Emission Inventory for China, MEIC). It turns out that the differences between simulations with the two emission inventories are much smaller than the differences between simulations and observations. Low-bias of precursor gases (e.g., SO2), too strong convergence of wind field, too strong dilution and transport by summer monsoon circulation, too much wet scavenging by precipitation, and too weak aerosol swelling due to low-biased relative humidity are suggested to be responsible for the biased AOD in eastern China. This indicates that the influence of emission inventory uncertainties on aerosol radiative forcing can be overwhelmed by influences of biased meteorology and aerosol processes. Therefore, it is necessary for climate models to perform reasonably well in the dynamical, physical and chemical processes in order to estimate the aerosol radiative forcing.

采用2014-2018年6-8月海口多普勒雷达、闪电定位、海南省天气分型等数据资料,分析海南岛分别在西南低压槽、南海低压槽、华南沿海槽影响下40 dBZ回波伸展到0℃层高度的概率,0℃层上强度≥40 dBZ的回波面积,地闪次数与0℃层上强度≥40 dBZ的回波面积比值,地闪次数及地闪发生概率等变量的时空分布特征,结果表明:(1)0℃层上强度≥40 dBZ的回波面积与地闪次数呈正相关.(2)午后40 dBZ回波伸展到0℃层高度的概率与地闪发生概率呈正相关.(3)午后40 dBZ回波伸展到0℃层高度的概率中心与地闪发生概率中心完全重合.(4)在华南沿海槽影响下,0℃层上强度≥40 dBZ的回波面积最大,同时地闪次数最多,午后地闪发生概率中心分布在以海口市南部为中心的海南岛东北部内陆.(5)在南海低压槽影响下,40 dBZ回波伸展到0℃层高度的概率最高,同时午后地闪发生概率最高,午后地闪发生概率中心分布在以儋州市南部为中心的海南岛西北部内陆.(6)在西南低压槽影响下,午后40 dBZ回波伸展到0℃层高度的概率、0℃层上强度≥40 dBZ的回波面积、地闪发生概率、地闪次数等指标在3种天气分型中最低,午后地闪发生概率中心分布在以澄迈县南部为中心的海南岛北部内陆.

ABSTRACT Tropospheric ozone plays an important role in atmospheric processes. However, the acquisition of tropospheric ozone content from satellite observations is a crucial challenge for atmospheric pollution research. In this study, the 0.25° × 0.25° tropospheric ozone column products over China were determined from total ozone columns measured by the Ozone Monitoring Instrument (OMI) and ozone profiler of the Microwave Limb Sounder (MLS). Calculation results were then validated with similar satellite products, Electrochemical Concentration Cell (ECC) ozonesonde observations, and simulation results from the Regional Atmospheric Modelling System – Community Multiscale Air Quality Model (RAMS-CMAQ). Validations shows that OMI-MLS calculation results correlate well with ozonesonde data, the correlation coefficient reached to 0.92. Compared to RAMS-CMAQ, OMI-MLS presents consistent distribution and the correlation coefficients range from 0.52 to 0.82.

A sounding system with electrical field and precipitation particles in thunderstorm is used for measuring humidity, temperature, the vertical component of electric field (E-field) and particle video. The ground system is used to continuously receive several signals sent by the sounding by tracking the GPS information carried by the sounding. This sounding system operated in a public frequency band of 2.4 GHz and used a fixed channel with the bandwidth of 20MHz to realize the point-to-point full-duplex communication. The ground system was connected to a parabolic directional antenna with high-gain of 27dBi. The real test showed that the maximum communication distance is about 15km which can well guarantee the field observation. The sounding was composed of GPS, temperature and humidity sensors, airborne vertical electric field measurement device, and precipitation particle video device.. GPS signal is very important for locating the balloon position and synchronously tracing sounding by antenna, and the measurement of vertical electric field used the corona probe as the sensor, and the ice phase precipitation particles were captured by a camera with frame rate of 25fl/s. A case of thunderstorm was obtained in the Pingliang of China. The results indicated that the balloon ascend through seven charge areas. A negative one located close to ground and a positive zone was above it in the warm cloud area. Other zones appeared at the area above melting layer and polarity of these was alternative changing. Another case showed the thunderstorm should have four charge regions with the lowest one is negative. However in actual observation, it still exists insufficient in recording the information of ice phase particles.

Analysis of soil resistivity in Haikou City for nearly one year, the soil moisture data, and the meteorological data information provided by automatic meteorological station, the results show that soil resistivity of Haikou shows the distribution features of the east side lower than the west; soil resistivity of volcanic ash soil changes in inverse u-shaped curve with the seasons, while the red soil and sand soil resistivity changes with the seasons in u-shaped curve, and soil resistivity of the volcanic ash is not reduced due to the rainy season, instead it increases; soil resistivity of volcanic ash rises with the increase of soil humidity, while the soil resistivity of red soil and sand soil decreases with the increase of soil humidity. The soil resistivity of volcanic ash and red soil decreases with the increase of soil temperature, while the soil resistivity of sand soil rises with the increase of soil temperature. The soil resistivity of volcanic ash and red soil rises with precipitation, while soil resistivity of sand and red soil rises with precipitation. The decline of red soil was most pronounced.

利用海南省地闪定位网获取的4年(2010年1月至2013年12月)地闪定位资料,详细分析海南岛地闪活动的时空分布特征,结果显示,海南岛的地闪活动主要发生在4-10月;呈双峰特征,峰值分别出现于5月和8月,分别约占全年总地闪数的23％和18％;地闪活动在6-7月明显地间歇性减少.从日变化特征来看,地闪在14:00-20:00时段最为频繁.16:00左右达到峰值,而5:00左右有一个较弱的峰值,2个峰值所占比例分别约为11.3％和4.2％.通过对比分析各地区的地闪活动,发现日变化呈现双峰特征的区域主要集中在东、南和西部沿海地区,而中部内陆及靠近琼州海峡的北部沿海地区呈单峰值特征.海南岛中部内陆山区的地闪密度大,沿海地区地闪密度小,并且存在2个地闪密度高值区.

Characteristics of lightning disaster in Hainan Island from 1999 to 2011 are analyzed by using nationwide lightning disaster data, thunderstorm data, lightning location data, and statistical yearbook of Hainan Province.The results show that 727 lightning disaster accidents are reported, which result in 405 casualties including 157 deaths and 248 injuries.Lightning casualty ratio is 1.58:1.The lightning disasters of Hainan Island mainly occur between 1:00pm and 6:00pm from April to September, which is in accord with lightning activity of Hainan Island.Haikou and Qiongzhong report the most lightning disaster accidents.Lightning disaster with casualty usually occur in field, simple shed, rural residential, water area and under the tree in sequence.Lightning disaster with damages occur most frequently in the power, petrochemical industries and three others, which account for 22.2% of the lightning disaster with damage.The hotel accounted for the largest proportion (34.7%) of the direct economic losses caused by lightning disaster.Lightning disasters with casualty and damage have no significant correlation with thunderstorm day, but lightning disasters with casualty and damage are positively correlated with life fragile module and economic vulnerability module.

Based on the cloud-to-ground (CG) flashes data from 2010 to 2013 obtained- by the VLF lightning locating networks in Hainan Province, the temporal and spatial characteristics of cloud-to-ground (CG) flashes activities were analyzed. The results indicated that more than 99% of CG flashes occurred between April and October and two peaks of CG activity appeared in May (23%) and August (30%).The CG flashes occur clearly with a characteristic of daily and monthly variation, in which there are two peaks. The peaks of daily variation occur at 5:00 am and 16:00 (Beijing time) almost. In terms of areas, the CG activities in the most coastal areas present the changing characteristic of double peaks. However, there is only a single peak in the inland areas and the northern coastal areas near the Qingzhou Strait. The first peak (the early peak) occur between 2:00 and 7:00 am, and the second one (the late peak) occur during the period from 12:00 to 17:00, where the CG activities present the double-peak characteristic. The spatial distribution of CG flashes presents certain regularity that the CG flashes density is the largest in the inland mountainous areas and the density becomes more and more small as the spatial position further outspread forward the coastal areas. In addition, there are two high value centers of the CG flashes density, and the spatial distribution of flashes density exist differences at different times especially in the south of Hainan Island and on the north of Wuzhishan mountain.

利用全国雷电灾害汇编数据,结合人工观测雷暴资料、闪电定位资料和海南省统计年鉴数据,统计分析了1999至2011年海南岛的雷电灾害特征.结果表明:1999至2011年间,海南岛共上报了727起雷电灾害事故,导致了405人伤亡,其中死亡157人,受伤248人,雷击人员伤亡比率为1.58:1;海南岛雷灾事故主要发生在4至9月的午后13至18时,这与海南岛的雷电活动规律一致;海南岛雷灾事故发生最多的依次是海口和琼中;人员伤亡雷灾事故依次主要发生在田野、简易工棚、农村民居、水域和树下;财产损失雷灾事故最频繁发生在电力、石化等五大行业,占总财产损失雷灾事故的22.2％,雷灾造成的直接经济损失中酒店类最多(占34.7％);人员伤亡雷灾和财产损失雷灾与雷暴日的相关性不显著,但与生命易损模数和经济易损模数呈现较好的正相关.

From the national collected data of lightning disasters from 1998 to 2009, the observational thunderstorm data of 18 meteorological stations, and lightning locating networks data and economy and population data in statistical yearbook of Hainan Province, the indices representing hazard-formative factor, hazard pregnant environment and hazard-affected body of lightning was selected. Through R-Cluster analysis, the indices influencing vulnerability were screened and checked. Based on 5 indices, i. e., thunderstorm days, lightning density above 50 kA, thunderstorm frequency, casualty frequency and regional vulnerability economic modulus as basic variables, similarity measures of samples were calculated. With Ward's method in Q-Cluster, the hierarchy cluster analysis was carried out and Q-iterative cluster was adopted to explain and testify the result of the cluster. Finally the zoning of lightning risk in Hainan Island was constructed. Results show that Haikou City is within the first category zone, whose vulnerability is extremely high, with comprehensive vulnerability as high as 3. 89; Wencang, Chenmai, Linggao, Dingan, Tuncang and Qionghai are in the second category zone, whose vulnerability is just next to the extremely high zones; Danzhou, Qiongzhong, Baisha, Tongshi, Baoting are in the third category zone with moderate risks; Changjiang, Dongfang, Ledong,Wannin, Lingshui and Sanya are in the fourth category zone with weak risks.

With the observed thunderstorm data of 18 meteorological stations and VLF lightning locating networks data in Hainan Province, the thunderstorm environment and the characteristics of the thunderstorm activities were analyzed for the Wenchang Rocket Launching Site. The results indicate that the thunderstorm activities in the central and northern parts are stronger than those in the western, eastern and the southern coast. The Wenchang Rocket Launching Site is located in the northern area where thunderstorm activities are strong. Fitting results using the Krigine method shows that annual thunderstorm days ( Td ) of the Wenchang Rocket Launch Site have reduced gradually after 1982. Thunderstorm activities occur all the year round, and are much stronger in months from April to October than in other months, west, northwest and north of the Launch Site have stronger thunderstorm activities than other areas. 79% of the lightning currents have the strength lower than 40 kA, while only 5. 9% of the lightning currents have the strength higher than 60 kA. The occurrence of the lightning flashes has two peak time intervals in a day, one appears from 5:00 am to 6:00 am, and the another appears from 2:00 pm to 6:00 pm. The highest frequency of lightning flash activities occurs around 3:00pm in the afternoon.

According to the data of lightning disasters from 1997 to 2010 and lightning observation by TRMM satellite,feature of national injuries and deaths from lightning is analyzed and the results indicate that lightning causes 460 deaths and 425 injuries every year on average.The mortality rate is 0.36 per million people and 0.48 per ten thousand square kilometers every year.Three indexes about lightning casualties reports,the number of lightning fatalities per ten thousand square kilometers and the number of lightning fatalities per million people have good correlation.Lightning-related casualties have increased for the period of 1997—2007 and then begin to decrease since 2008.Casualties anomaly percent is positive in the year of 2002,2004,2005,2006 and 2007,with the maximum value in 2007,when the ratio is 78%more than normal years. In order to reveal the vulnerability of lightning which lead to injuries and deaths in different region,Rcluster analysis is used for sifting the 8 indexes affected by vulnerability evaluation.Lightning density, casualties frequency,population,and region areas are selected as variables.Comparability measures of each sample are calculated by using Euclidean distance,and then the method of Q-cluster is used to analyze and calculate these date.Finally the results of 6 different kinds of risk zones of lightning that lead to injuries and deaths in China are given.Guangdong and Hainan pertain to vulnerability evaluation extreme high areas.In these areas,the comprehensive vulnerability evaluation of cluster reaches up to 5.017,where both the average density of lightning and personnel casualty rate is the highest in the six categories.In the opposite,the northwest and northeast of China are areas with the lowest vulnerability.Finally,Ward's method of Q-cluster is adopted to explain and testify the result of cluster,showing the cluster solution is not only stable but also reliable.The result of the classification is appropriate,and preferably reflects regional vulnerability characteristics of lightning-caused casualties.

Ground lightning flash density Ng is one of most important parameters in lightning risk assessment.The conventional method of lightning risk assessment is to adopt the observed annual-mean number of thunder days(Td) from local meteorological stations to calculate Ng and consider it a constant for one city or even a certain area,which is of certain limitations as the distribution of lightning is depended on the topographical,geological,edaphic,meteorological,and environmental features.Based on the conception of Ng,the processed data from the calibrated lightning location system and the calculated Td by Kriging interpolation,a corresponding program is developed by the C# language to obtain more reliable values of Ng in a more convenient way for the use of lightning risk assessment.

根据琼海市广播电视台建筑物地理分布、结构及雷击环境、气象状况、土壤电阻率等综合条件,分析雷击隐患和防护需要,从整体上提出针对性的防护措施,为电视台整体雷电防护提供参考.

Basing the lightning risk business systems of Hainan,east longitude 110.367 and degrees north latitude 18.8 degrees of Wanning city urban were selected as reference points.Using Kriging method with 1km grid density,Month and year variation of thunderstorms were calculated and analyzed as well as daily variations in flash intensity and the distribution of lightning current.A number of lightning protection measures were put forward.

Hydrosphere movement in coastal zone performs as salty and fresh water mutual function. The Longkou city coastal zone which moves in the humanity under the intervention, has initiated the large-scale sea water intrusion, and therefore was especially under severe circumstances since 1980s. Until the end of 1980s and the beginning of the 90's, the sea water intrusion zone has formed the belt which spread fast from several hundred meters to several thousand meters along the coastal zone of Longkou city. Taking the landsat TM images in 2000 as data sources, first we applied the principal components transformation and analysis to analyze the six TM wave bands, and then use the histogram equalizing to deal with them. We use the two-value approach to be possible to remove the villages and small towns, the path, the pond (fishpond), the vegetables greenhouses, the rivers, the sand very conveniently. We take wave band as the research band, TM3, TM4 and TM5, which passed through correlation coefficient confirmation. Using the principal components analysis method to determine vegetation degree of coverage, the bare land index and the green index, the humidity analyzed in turn as four factors of the sea water intrusion. Inversion model of sea water intrusion is build up with the four factors. Finally a case study on the Longkou city, the analysis is obtained that the results have a very good correlation with the field measurements, and in accordance with the extent of the intrusion is divided into four categories.

With the use of lightning location data,combined with manual observations,automatic weather station data and climate monitoring terrain information of Hainan Island in 2007,the characteristics of lightning frequency,intensity, mechanism,distribution were preliminary analyzed.The monthly frequency of lightning,the intensity changes,the main mechanism and the main factors affecting distribution were also discussed.