硫铝酸盐水泥去除微污染水体中磷的性能及机理

微污染湖泊、水库等水体中磷的去除已成为水质研究的主要方向.磷是造成水体富营养化的关键因素,其浓度较低时即可导致水体富营养化与水华的发生,许多除磷方法对低浓度磷的去除效果不佳.因此,我们从22种天然矿物、火山灰质材料和水硬性材料中,筛选出了能高效去除低浓度磷的硫铝酸盐水泥(代号R.SAC 42.5,简称R),该材料在中性...     

IMERG卫星降水产品在我国梅雨极端降水期的适用性评估

为考察GPM卫星降水产品IMERG在梅雨极端降水期的适用性,以中国自动气象站观测数据与CMORPH降水产品融合的逐时降水量网格数据集资料作为参考,采用均方根误差RMSE和平均绝对误差MAE统计指标,对IMERG卫星降水产品在长江中下游地区2020年梅雨极端降水期的适用性进行评估。结果表明:IMERG卫星降水产品整体上与实测结果趋势一致,对于12 h和24 h累计降水,在强降水区域易出现高估。反演的3 h累计降水与实际降水一致性较好,累计降水量大于20、50、80、100 mm四种情况下的RMSE和MAE平均值均为10 mm左右。     

苏北盘石山、练山地幔捕虏体的PGE地球化学

通过锍镍火试金预富集法,分析了位于郯庐断裂带东侧的盘石山、练山地幔橄榄岩包体中铂族元素(PGE)和Au含量.不同于部分熔融残留成因地幔橄榄岩中通常所观察到的负斜率型或平坦型的分布模式,这两地的地幔橄榄岩以Pt、Pd、Ru相对富集,Ir、Rh相对亏损的"燕子型"分布模式为特征.Pt、Pd等不相容元素富集说明上地幔除经历过早期的部分熔融外,还经历了后期富Pt、Pd的高熔/岩比的熔(流)体的层析分离交代作用影响.盘石山地幔橄榄岩的PGE总量比练山高,Os的含量也比原始地幔值高;而练山地幔橄榄岩的Os含量比原始地幔值低,说明交代作用带走了练山地幔橄榄岩中的Os,却没有很大改变盘石山地幔橄榄岩中的Os含量,这可能与交代熔(流)体含硫量饱和程度有关.Rh的负异常可能与部分熔融过程中熔体较低的fo2有关.     

Response of riparian vegetation to water-table changes in the lower reaches of Tarim River, Xinjiang Uygur, China

The lower reaches of Tarim River in the Xinjiang Uygur region of western China had been dried out for more than 30 years before water began to be diverted from Konqi (Peacock) River via a 927-km-long channel in year 2000, aimed at improving the riparian ecological systems. Since then, eight intermittent water deliveries have been carried out. To evaluate the response of riparian vegetation to these operations, the groundwater regime and vegetation changes have been monitored along the 350-km-long stem of the river using a network of 40 dug wells at nine transects across the river and 30 vegetation plots at key sites. Results show that the water table rose remarkably, i.e. from a depth of 9.87 m before the water delivery to 3.16 m after the third water delivery. The lateral distance of affected water table extended to 1,050 m from the riverbank after the fourth water delivery. The riparian vegetation has changed in composition, type, distribution, and growing behavior. This shows that the water deliveries have had significant effects on restoration of riparian ecosystems.     

Low-mass and high-mass supermassive black holes in radio-loud AGNs are spun-up in different evolution paths

How supermassive black holes(SMBHs) are spun-up is a key issue in modern astrophysics. As an extension to the study in Wang et al., here we address the issue by comparing the host galaxy properties of nearby(z 0.05) radio-selected Seyfert 2 galaxies. With the two-dimensional bulge+disk decompositions for the SDSS r-band images, we identify a dichotomy in various host galaxy properties for radio-loud SMBHs. By assuming that radio emission from the jet reflects a high SMBH spin, which stems from the well-known Blandford-Znajek mechanism of jet production, high-mass SMBHs(i.e., MBH 107.9 M⊙)have a preference for being spun-up in classical bulges, and low-mass SMBHs(i.e., MBH = 106-107 M⊙)in pseudo-bulges. This dichotomy suggests and confirms that high-mass and low-mass SMBHs are spun-up in different ways, i.e., a major "dry" merger and a secular evolution respectively.     

深孔绳索取心安全打捞器的研制与应用

设计了一种可适用于深孔和干孔的绳索打捞、投放内管总成工具。介绍了深孔绳索取心安全打捞器的工作原理及结构组成;对工具内部的机械控制和井下脱卡控制原理进行了研究;介绍了打捞器井下脱卡的具体方法;最后通过野外试验证实了该打捞器可以减少处理事故的时间,性能稳定,拆装、维护方便。     

X-ray activity from different types of stars

X-ray emission is an important indicator of stellar activity. In this paper, we study stellar Xray activity using the XMM-Newton and LAMOST data for different types of stars. We provide a sample including 1259 X-ray-emitting stars, of which 1090 have accurate stellar parameter estimations. Our sample size is much larger than those used in previous works. We find a bimodal distribution of the X-ray to optical flux ratio(log(fX/fV)) for G and K stars. We interpret that this bimodality is due to two subpopulations with different coronal heating rates. Furthermore, using the full widths at half maxima calculated from Hα and Hβ lines, we show that these stars in the inactive peaks have smaller rotational velocities. This is consistent with the magnetic dynamo theory that presumes stars with low rotational velocities have low levels of stellar activity. We also examine the correlation between log(fX/fV) and luminosity of the excess emission in the Hα line, and find a tight relation between the coronal and chromospheric activity indicators.     

青田山口叶蜡石传压介质初步研究

采用青田山口叶蜡石作为超高压高温合成金刚石的传压介质，分析了其主要化学成分和矿物组成。对青田山叶蜡石粉压块粒度效应进行了研究，确定了该传压介质的粒度组成。超高压高温人造金刚石试验表明，青田山口叶蜡石的传压介质理想，金刚石合成效果较好。     

Study on rain-runoff process in the peripheral mountainous area of the Sichuan Basin

Studies on rain-runoff process in the peripheral mountainous area of the Sichuan Basin, which is regarded as a key ecological shelter, will contribute to flood control and environmental protection for the Upper Yangtze River Basin. In two typical catchments--the Fujiang River Catchment and the Wujiang River Catchment, rainfall simulations have been conducted to study the rain-runoff processes of yellow soil and limestone soil in three types of land use--forestland, farmland and grassland. Results showed that （1） within the same rainfall process, overland flow occurs first on farmland, then on grassland, and finally on forestland; （2） soil surface coverage has a great impact on the occurrence and amount of overland flow. The runoff amount can increase 2-4 times after the coverage is removed; （3） the infiltration before the occurrence of overland flow will decrease because of higher gravel contents of soil, but it takes no effect on infiltration once overland flow becomes stable; （4） the runoff coefficient of the limestone soil forestland is greater than that of the yellow soil forest land, but less than that of the farmland; （5） three empirical infiltration models, including Horton＇ model, Kostiakov＇ model, and modified Kostiakov＇ model, were compared by using the observed results under rainfall simulation. The results showed that the Kostiakov＇ model performed better than both the Horton＇ model and modified Kostiakov model. According to the results of this research, the Kostiakov＇s model can be used to simulate rainfall infiltration when water erosion is modeled in the peripheral mountainous area of the Sichuan Basin.     

内蒙古北山地区阿民乌素公婆泉组变质火山岩年代学、地球化学特征及地质意义

内蒙古北山地区阿民乌素一带公婆泉组变质火山岩主要由钠长阳起岩、斜长阳起岩和斜长阳起片岩组成.三者主量元素显示相对高钠w(Na2O)=0.32％～2.46％,低钾w(K2O)=0.08％～0.38％、钛w(TiO2)=0.93％～1.03％,略富镁 w(MgO)=9.61％～12.04％、钙 w(CaO)=9.96％～1...