软骨黏液样纤维瘤的影像分析

目的:探讨软骨黏液样纤维瘤（CMF）的影像学特征。资料与方法:回顾分析18例经手术病理证实的软骨黏液样纤维瘤的影像资料，女性12例，男性6例，平均年龄30岁，范围9岁～78岁。分析其平片（15例），CT（8例）及MRI（10例）表现特征。结果:发生于股骨3例，胫骨3例，肱骨2例，掌骨2例，颞骨2例，额骨2例，尺骨1例，腓骨1例，跟骨1例和胸椎1例；10例位于长骨，其中干骺端7例，骨端2例，骨干1例；11例呈类圆形或椭圆形，4例呈分叶多房状，3例呈不规则形，均呈不同程度膨胀。CMF在平片及CT上病灶均为溶骨破坏，平片显示4例（26.67%）钙化，CT显示6例（75%）钙化；在MRI的T1WI表现为低至中等信号，T2WI表现为不均匀中高信号，其中80%（8/10）为外周中高信号，中央区高信号，增强后呈不规则环形强化，20%（2/10）呈弥漫性不均匀中高信号，增强后呈弥漫不均匀强化。结论:CMF影像表现具有一定的特征，其MRI信号及强化特点在CMF诊断及鉴别诊断中有重要作用。      

贵州百花湖分层晚期有机质降解过程与溶解N2O循环

百花湖是一个具有季节性分层的富营养小型湖泊,在秋季湖水倒转期经常发生水质恶化事件,碳氮循环出现异常。文章研究特选择在秋初,湖泊分层开始消失时,测定了湖水中不同深度的N₂O,CH₄,CO₂,有机和无机碳同位素以及其他化学参数变化。结果发现:采样时百花湖在约6m和16m深度附近出现了两个温度不连续层(SDL和PDL),并影响到有机颗粒的沉降和分解。相对而言,有较多的有机质在这两个层内发生降解,但降解的途径有所不同,上部主要是有氧降解,下部则主要是无氧降解过程。N₂O的产生和消耗与有机质的降解过程完全对应:PDL层以上,ΔN₂O与AOU的线性关系反映了N₂O主要形成于硝化作用;PDL层以下反硝化作用导致N₂O严重不饱和;PDL内位于硝化作用和反硝化作用过渡带的N₂O峰,显然是硝化与反硝化联合作用的结果。PDL层内较大的CH₄浓度变化梯度,说明嗜甲烷细菌可能通过氧化NH+4贡献了部分N₂O。百花湖秋、冬季表层湖水N₂O都是过饱和的,都是大气N₂O的源,依据分子扩散模型计算湖泊N₂O的释放通量在12～14μmol/m·day之间,秋、冬季没有明显的差别。秋季底层湖水的反硝化作用是湖泊N₂O的汇,其消耗通量与表层的释放通量基本相当。     

杂卤石溶解性能的测定

通过测定25℃，50℃，75℃时液相K^ ，Ca^2 ，Mg^2 ，SO4^2-等组成浓度随时间的变化，考察杂卤石在水中的溶解行为，测试得25℃，50℃，75℃条件下杂卤石中K^ 在水中的平衡浓度分别为19．13，21．29，36．77(mg／m1)。K^ 溶解平衡浓度随着温度的升高而增大。实验研究25℃条件下杂卤石在CaCl2溶液中的溶解行为。在5％和10％CaCl2溶液中K^ 的平衡浓度分别为25．65，35．24(mg／m1)。明显大于在水中的平衡浓度。表明CaCl2对杂卤石具有明显的增溶作用，可作为杂卤石的良好溶浸剂。实验结果对不溶性或难溶性的钾矿资源的开发利用具有理论参考和实际应用价值。     

清丰水化站水中溶解气二氧化碳观测资料的研究

对清丰水化站地下水中溶解气CO2多年的观测资料序列进行了研究分析,其结果是:该测项对观测装置的改变及抽水量的变化反映灵敏;对本观测井所在构造带上的4.0级以上的地震,有明显的前兆异常;该测项与大气压力及气温的相关系数跟各时段的抽水量和抽水装置的吃水深度有关.     

~(40)Ar-~(39)Ar Age and Geological Significance of the Sawur Gold Belt in Northern Xinjiang, China

1 IntroductionThe Sawur gold belt is an eastward extending section ofthe Zarma-Sawur gold-copper belt in Kazakhstan, locatedin the Sawur Mountain, northern Xinjiang, and mainlycomprises two large- to medium-sized gold deposits,accompanied by five small gold deposits and a series ofgold ore spots (Yin et al., 1996, 2003; Wang et al., 1999; Liet al., 2000; Liu et al., 2003; Shen et al., 2004a). TheKuo'erzhenkuola and Bu'erkesidai gold deposits are thebiggest and most important ones in this …     

贵州喀斯特地区河水中溶解态微量元素地球化学

本文主要研究了贵州喀斯特地区乌江流域和沅江流域河水中溶解态微量元素Pb、Cu、Co、Ni、Fe、Mn、Zn、Rb、Sr、Ba和U等的组成.研究结果表明,流域盆地的地理岩性控制了河水的微量元素化学组成.由于河水的pH值较高,控制河水中溶解态微量元素的机制是吸附/解析-沉定-溶解平衡.     

Characteristics of natural low pH groundwater in the coastal aquifers near Beihai, China

Groundwater with low total dissolved solids （less than 200 mg/L） occurs in the unconfined and confined aquifers near Beihai in southern Guangxi, China. Under natural conditions the groundwater ranges in pH from 3,33 to 7,0 with an average value of 5.12. The pH in the unconfined aquifer varies from 3.67 to 7.0 with an average value of 5.17 and the pH in the confined aquifer is in the range 3.33-6.97 with an average value of 5.07. The pH in the groundwater does not show significantly increasing or decreasing trends with time. Fluctuations in pH exist at some of the monitoring wells and the pH in groundwater is a bit higher in the rainy season than in the dry season, Monitoring data show that the pH in rainwater is higher than in groundwater in the unconfined aquifer, whereas the pH in the latter is a bit higher than in the confined aquifer. A slightly decreasing trend in the pH was also found from the inland area to the coastal zone. The occurrence of weakly acidic groundwater in this area is attributed to the recharge from low pH precipitation and the multi-aquifer and leaky groundwater system.     

Quantification and characterization of condensed organic matter in sediments from the Pearl River Delta and Estuary, South China

Nonhydrolyzable carbon （NHC） and black carbon （BC） were measured upon treatments with the HCl/HF/trifluoroacetic acid method, and with the combustion method at 375 ℃, respectively in three contaminated soils from the urban area of Guangzhou and twenty-two bulk and size-fractionated sediments from the Pearl River Delta and Estuary, China. The isolated NHC and BC fractions were also characterized using elementary analysis, radiocarbon accelerated mass spectroscopy （AMS）, solid state ^13C cross-polarization and magic angle spinning unclear magnetic resonance spectroscopy （^13C-CP/MAS NMR）, Fourier transformed infrared spectroscopy （FTIR）, and Raman microspectrometry. The results showed that the NHC and BC accounted for 25.6%-84.7 % and 4.14%-17.3%, respectively, of the total organic carbon （OC） with averages of 51.9% and 11.2% in the soils and sediments. For the less contaminated, low OC fiver and estuary sediments （WR and C08）, the OC and NHC concentrations increased with decreasing particle size.