Geochemical Characteristics and Chemical Electron Microprobe U-Pb-Th Dating of Pitchblende Mineralization from Gabal Gattar Younger Granite, North Eastern Desert, Egypt

Pitchblende mineralization was studied in the younger granite samples collected from Gabal Gattar, north Eastern Desert, Egypt using electron scanning microscope (ESM) and electron probe microanalyses (EPMA). This study revealed that this pitchblende contains significant Zr content reaching up to (66.80% ZrO2), which suggests that volcanic rocks were probably the source of such a deposit. High level emplaced high-K Calc-alkaline plutons as Qattar granite may have been associated with their volcanic equivalent emplaced in the surrounding area or now eroded. Lead content of the pitchblende mineralization is high and with moderate volcanics (up to 7.71% PbO). In contrast, it is low in ThO2, Y2O3 and REE2O3. High Zr and Pb content associated with pitchblende mineralization from Gattar granite indicates that the source of this mineralization derived from volcanic magma not from granitic magma. According to the calculation of U-Pb chemical ages using U, Th and Pb content measured with an electron microprobe for this pitchblende yielded ages within 543 - 657 Ma indicating a Pan-African age for this mineralization. This is the first time that a Pan-African age (543 to 657 Ma) is recorded for a U-mineralization in Gabal Gattar younger granite in the north Eastern Desert, Egypt.

Rotate Two Different Mode of Actions of Green Chemicals to Combat Virachola livia （Klug） on Date Palm Fruit, Egypt

Alternation of two different modes of action of green chemicals： spinosad and methoxyfenozide to combat Virachola livia on dates in Dakhla Oasis, New Valley, Egypt, were done in 2010 and 2011. Based on infestation levels in fruit, the three spray programs including rotations with spinosad 24 SC at 20 mL/100 L were not significantly different. Based on minimum effective rotation doses, alternation of spinosad at 20 mL/100 L followed by methoxyfenozide 24 SC at 15 mL/100 L on a three-week interval showed 0.3% and 0.6% infestation, before harvest for 2010 and 2011, respectively, compared to check treatments which showed 33% and 70% infestations. Also, successful penetration and survival of V. livia （% live larvae） into the fruit by following a spinosad and methoxyfenozide rotation program resulted in 1.8% and 1% larvae, before harvest in 2010 and 2011, respectively, compared to fhait infestation levels of 97% and 89% in the untreated in 2010 and 2011, respectively. Fruit were penetrated by first instar larvae upon hatching, in case no chemical treatment. The last data reflect the excellent performance of this rotation. During the same period, reduction of the three rotation programs was 97.8%-100% and 99%-100% for 2010 and 2011, respectively. Both products proved to be working under dry hot temperatures in these areas.

Alternate Two Different Modes of Actions of Green Chemicals to Combat Batrachedra amydraula Meyrick and Cadra cautella Walk on Date Palm Fruit, Egypt

Alternate two different modes of actions of green chemicals： spinosad ＆ methoxyfenozide to combat the lesser date moth, Batrachedra amydraula and the Almond moth, Cadra cautella Walk on dates in Dakhla Oasis, New Valley, Egypt were done in 2010 and 201 I. Based on infestation of the early insect pest B. amydraula, the three-rotation program with basic 1st spray of spinosad 24 SC at 20 mL/100 L showed insignificant difference. Based on minimum effective rotation doses, alternating spinosad 24 SC at 20 mL/100 L, then methoxyfenozide 24 SC at 15 mL/100 L with two-week interval showed zero infestation and 1.8% at the last sample of 2010 and 2011, respectively. Based on infestation of the late insect pest, Cadra spp., tlhe same previous trend of the three-rotation results. Based on minimum effective rotation doses, alternating spinosad 24 SC at 20 mL/100 L, then methoxyfenozid 24 SC at 15 mL/100 L with three-week interval indicated less than 1% and 1% infestation during harvest for 2010 and 201 l, respectively. The last reflected important value when storing the fruit. Both products proved to be working under dry hot high temperatures.

Chemical Composition and Antioxidant Activity of Date Seeds from Different Tunisian Date Palm Cultivars

Chemical composition,polyphenolic and flavonoid contents,and antioxidant activity were determined in date seeds derived from four Tunisian date palm(Phoenix dactylifera)cultivars namely:Goundi,Chekena,Mnekher and Remtha.Sodium and potassium contents in date seeds were determined by flame photometry,phenolic compounds by the Folin-Ciocalteu method,flavonoids by colorimetric quantification,and the antioxidant activity by the DPPH free radical scavenging method.Crude protein content varied widely(p<0.001)between date seed varieties and ranged from 3.95(Goundi)to 7.51%DM(Chekena).No significant differences(p>0.001)were detected between seed varieties for their dry matter(DM)and ash contents.However,sodium,potassium and phosphorus varied widely(p<0.001)between varieties.The highest phenolic content(p<0.001)was observed in Goundi(39.4 mg gallic acid equivalent(GAE)/g DM)and Remtha(36.6 mg GAE/g DM)seed varieties.Likewise,Goundi had the highest(p<0.001)flavonoid content(16.4 mg quercetin equivalent(QE)/g DM)and antioxidant activity(1,807μM Trolox equivalent antioxidant capacity(TEAC)/g DM);however the lowest values(p<0.001)of phenolic(19.2 mg GAE/g DM),flavonoid(8.8 mg QE/g DM)and antioxidant activity(682μM TEAC/g DM)were observed for Chekena seeds.Further studies are needed to verify the potential of date seeds as alternative for animal nutrition.

Coal-based energychemicalengineering:Pay one’srespectsto Prof.KechangXie

Coal is of utmost importance for the energy and chemical engi-neering fields of China,as it contributes to 56.8%of primary energy supply in 2020 in the country.On the one hand,coal is the major source of energy and resources for its rich endowment in China;However,on the other hand,it is the major source of environmen-tal pollution due to the implementation of outdated technologies.Therefore,according to Professor Kechang Xie in 2004,“The only way out is to develop and promote the clean and efficient coal uti-lization technologies”.In the past 40 years,China has made a sig-nificant progress in research and development related to modern coal chemical engineering,including lab-scale fundamental research and industrial-scale construction of many giant chemical plants.

Comparative Study on Five Sudanese Date (<i>Phoenix dactylifera</i>L.) Fruit Cultivars

The date palm (Phoenix dactylifera L.) is one of mankind’s oldest cultivated plants. A date palm fruit is an important component of the diet in most of the hot arid and semi arid regions of the world. The present study aimed at investigating the physical and chemical properties as well as microbiological characteristics of five date palm cultivars cultivated in Sudan. The results showed that the physical characteristics like fruit weight, length, flesh thickness, seed weight differed significantly between the various cultivars. Although most of the cultivars had similar chemical components, there were some few differences. However, the microbiological analyses proved that no significant differences were found among the cultivars.

Effects of Transplanting Date on Growth, Development, Yield and Quality of Flue-cured Tobacco in Western Henan

With Yunyan 87 as an experimental material, the effects of different transplanting dates on the growth and development of tobacco plants and the yield and quality of cured tobacco leaves were studied in Lingbao City, Sanmenxia City. With the postponement of transplanting date, the growth period in field was prolonged, and the plant height and leaf area both increased at first and decreased then. TMV, weather fleck and brown spot all showed an incidence and a disease index decreased with the postponement of transplanting date. The total sugar and reducing sugar contents of the cured tobacco leaves from the upper and middle part increased at first and decreased then with the postponement of transplanting date. The main nitrogenous compounds decreased at first and increased then. The economic traits and leaf class were on the decrease.

Heavy Metals and the Alternate Bearing Effect in the Date Palm (<i>Phoenix dactylifera</i>)

The alternate bearing effect is when plants produce abundant crops of fruit in some years, but sparse yields in others. This review summarises recent studies that suggest a connection between the alternate bearing effect in the date palm, Phoenix dactylifera, and the presence of certain chemical elements (mostly metals) in the tree tissues. So far, there is evidence that levels of Ag, B, Ba, Ca, Cd, Cu, Fe, K, La, Mg, Mn, N, Na, Se, Tl, and Zn in the dates and leaflets are affected by the alternate bearing phenomenon. The significance of this work, therefore, emphasises the prospect of using our experimental data to overcome sparse yields, due to the alternate bearing effect, and producing more prolific growth of fruits. The potential agricultural, economic, environmental and health implications of these findings are considered.

Food Value of Soft Dates Cultivated in Tunisian Coastal Oases

Coastal date palm cultivars are interesting through their soft dates, their abundant and earliest production than continental cultivars. Maintaining bio-diversity in Tunisian oases has become a subject of first interest in date palm cultivation in Tunisia. Coastal oases still retain a very rich and varied plant biodiversity in comparison with the continental oases, weakened by the mono cultivation of ＂Deglet Nour＂ cultivar. Study of soft date＇s composition can make there well known to date consumers, help to valorize there and to help of sustainability of coastal oases ecosystem. Fresh dates from 15 cultivars was collected, dried by 80 ~C in 20-24 h. Acidity was determinate by pH meter. Sugars were appreciated by enzymatic method. Ash and minerals was calculated by photometer and spectrometer. Chemical date composition study showed that coastal date palm cultivars are predominantly rich of carbohydrates, have a low quantity of sucrose which gives them an important dietary value. Their pH varies from 5 to 6, classifies them as the best date quality for fresh consumption. Their richness in Total Nitrogen Matters and total minerals makes them at almost the same level as the other date palm eultivars analyzed by different authors in different areas of date palm production. Mineral composition showed that these dates are K and P-rich and relatively poor in Na and Ca.

湘东明月峰地区金管冲铀矿床沥青铀矿电子探针U Th Pb化学定年及其地质意义

金管冲铀矿床位于湘东明月峰地区,属花岗岩外接触带型铀矿床,主要铀矿化类型为沥青铀矿方解石和沥青铀矿微晶石英萤石。为厘定金管冲地区的铀成矿时代与成矿期次,开展了详细的野外地质调查、岩相学、电子探针化学分析以及U Th Pb化学定年研究。结果表明,两类沥青铀矿的UO_(2)含量高、PbO与SiO_(2)含量低,且w(CaO)与w(UO_(2)+PbO)、w(SiO_(2)+CaO+FeO)与w(PbO)以及沥青铀矿年龄均无明显相关性,表明沥青铀矿形成时较为稳定,受后期改造作用影响弱。金管冲铀矿床中沥青铀矿方解石型铀矿化加权平均年龄为(90.7±3.2)Ma(MSWD=1.9,n=17),沥青铀矿微晶石英萤石型铀矿化加权平均年龄为(70.1±2.4)Ma(MSWD=2.1,n=20),显示该矿床在晚白垩世至少经历了两阶段的铀成矿作用。综合前人已有数据,认为金管冲铀矿床铀成矿作用与华南岩石圈拉张减薄事件较为吻合,可能是古太平洋板块俯冲后的产物。

Effect of chemical composition on zircon radiation damage dating:Implications for low-temperature thermochronology

Zircon radiation damage dating is a low-temperature thermochronological method that can reveal the cooling histories of magmatic intrusions and discriminate sedimentary provenance in combination with other dating methods.This method has broad application prospects because of its advantages of nondestructive,high efficiency,and capable of double(or multiple)dating,involving only multiple measurements by Raman spectrometer and laser ablation-inductively coupled plasma-mass spectrometry.However,several factors,such as zircon chemical composition and the non-uniformity of radiation damage annealing kinetics,can cause poor precision when using this method and thus restricts its wide application.This study examined the effect of chemical composition(P,Ti,Dy,Th,U,and Hf)on Raman spectra using synthetic zircon crystals grown in a lithium-molybdate flux.The results show that the full width at half-maximum(FWHM)of the v_(3)(SiO_(4))band has positive linear correlations with the concentrations of P,Ti,Dy,Th,and U in decreasing order of influence,while the FWHM is unaffected by Hf at concentrations<1 wt.%but increases at concentrations>10 wt.%.Furthermore,the Raman shift is negatively correlated with Th,U,and Dy concentrations,positively correlated with Hf,and shows no obvious correlation with Ti and P.Thus,our study shows that chemical composition is a non-ignorable factor for calculating zircon radiation damage age using Raman spectroscopy,especially for zircon with relatively high concentrations of P,rare earth elements(REEs),Th,U,and Hf.The obtained multiple linear regression equation provides a potential means for estimating the FWHM at zero dose and implication for improving the dating precision of this method.In addition,the observed effects of REEs,Th,U,and Hf on the Raman shift of the v_(3)(SiO_(4))band indicate that chemical composition in zircon might affect the estimation of the P-T conditions of geological processes when using entrapped zircon inclusions in host minerals or the field of zircon as an in situ pressure sensor in hydrothermal experiments.Our study suggests that zircon radiation damage dating,excluding geochemical effects,will be more accurate for addressing lower-temperature geological processes.

光石沟铀矿床晶质铀矿电子探针化学定年研究

铀成矿年龄是铀矿床研究的重要内容,如何准确有效的测定铀矿床的成矿年龄一直是铀矿地质工作者不断探索的课题。应用电子探针化学定年方法对陕西丹凤光石沟伟晶岩型铀矿床中晶质铀矿进行了微区定年工作,光石沟铀矿床中晶质铀矿的微区特征及成分信息显示,晶质铀矿形成后一直处在封闭体系之中,后期没有经历热液流体的蚀变改造。本次获得两颗晶质铀矿的成矿年龄分别为(407.6±8)Ma和(416.9±10)Ma,与该矿床的U-Pb同位素稀释法测定的晶质铀矿年龄一致。

鄂尔多斯自流盆地地下水来源争议问题讨论

本文讨论了鄂尔多斯自流盆地地下水来源存在争议的两种学术观点,指出了前人关于鄂尔多斯地下水补给、径流、排泄模型所存在的问题:①在四水转化过程中缺少了最重要的研究内容——土壤水的运动,通过概念模型得到的地下水循环模型不能解释地下水分水岭与基底断裂带重合的事实。②部分学者在进行地球化学反向模拟的的研究中,没有对白云石、方解石中的同位素进行对比分析,碳同位素不支持模拟分析结果。③采用14C测定地下水年龄中受到深部CO2的干扰,在中国北方地区不适合采用14C测定地下水的年龄。笔者等通过黄土剖面土壤水中的氘—氧同位素与Cl-分布特征,指出鄂尔多斯盆地的降水非但不能补给到地下水中,而且土壤水的主要来源是地下水。鄂尔多斯自流盆地的主要补给源是外源水,深大断裂带是导水的主要通道。

电子探针化学测年法在晶质铀矿/沥青铀矿定年研究中的应用现状

简要介绍近年发展起来的各种微区测年方法及其优缺点,重点介绍不同时期电子探针化学测年法在晶质铀矿/沥青铀矿定年研究中的发展状况及前人使用的分析测试条件,并展望了该方法在晶质铀矿/沥青铀矿定年研究中的应用前景及可能存在的问题。通过系统研究,认为该方法在铀矿物定年研究中将大有作为,尤其是在微小铀矿物(<10μm)和多期次、多阶段铀矿体的微区定年研究中更能显示其优越性。

东海超高压榴辉岩中绿帘石、褐帘石、磷灰石和钍石集合体的电子探针成分和化学定年研究

中国大陆超深钻(CCSD)主孔从100米到3000米切穿含柯石英榴辉岩,为系统研究大陆深俯冲过程中含稀土元素副矿物提供了机会。本文报道了该钻孔榴辉岩存在发现的绿帘石、褐帘石、磷灰石和钍石复合颗粒。它们以同心环带结构为特征,从边部向中心依次为绿帘石、褐帘石和磷灰石;钍石既可包裹再磷灰石中,也可见于褐帘石中。电子探针分析显示,褐帘石不仅含有较高的轻稀土元素(LREE2O3=23．36wt％),而且可含有2．6wt％ThO2。根据绿帘石和褐帘石的电子探针高分辨U、Th、Pb成分计算得到绿帘石边部的形成年龄为738±88Ma,该年龄与大别-苏鲁地体榴辉岩的元古代源岩的年龄相当,因此,绿帘石可能为残留相。相反,褐帘石的年龄为220±41Ma,与大别-苏鲁超高压变质年龄相近。因此,褐帘石与磷灰石和钍石一起应该为超高压变质事件的产物。根据绿帘石、褐帘石及其共生的磷灰石和钍石的结构、成分特征和化学定年结果,我们推测绿帘石与可能已完全消耗的独居石很可能为变质副矿物组合的先驱矿物。独居石-绿帘石复合颗粒在榴辉岩相高压／超高压变质过程中反应形成磷灰石+钍石+褐帘石组合。

不同播期对烤烟品种产量和品质的影响

为了探索韶关烟区适宜的播种期和移栽期,以6个优质烤烟品种(品系)为材料,进行分期播种,塑造不同的光温气候条件,以优质中部烟叶化学成分为参考样,用指标赋值法对烤烟(等级为C3F)化学品质进行综合评分,依品质优劣将不同品种排序。结果表明:播期显著影响烤烟品种的产量和品质的形成。产量高低决定产值高低,适当推迟播期有利于提高烤烟产量和产值;但播种过迟会严重降低产量,降低烤后烟叶中上等烟比例,导致产值下降。烟叶化学品质中烟碱含量、总氮含量、淀粉含量、钾含量均受播期影响,随着播期延迟C3F烟叶的烟碱含量、总氮含量、钾含量减小,淀粉含量明显增加,影响烤烟品质;但3个播期中各品种的氮碱比、糖碱比、钾氯比变化因品种而异。在3个播期试验品种中,各品种的C3F品质平均综合评分表现为"云烟100"、"NX208"、"K326"的评分相对较高,C3F烟叶品质较好。适当的播种期使得烟叶化学成分的协调性好,利于提高烤烟的产量和品质。不同播期试验表明,韶关烟区适宜播种期为12月1日—12月10日,适宜移栽期为次年2月25日—3月5日。

一种简单的辉钼矿Re-Os同位素年龄测定中Re化学分离方法:“钽试剂”萃取法

介绍了一种简单的辉钼矿Re-Os同位素定年中Re的化学分离方法,采用"钽试剂"(N-苯甲酰基苯基羟胺)的氯仿溶液萃取辉钼矿中的主要基体和干扰元素,如Mo、Fe和W,达到Re与这些主要基体元素分离的目的。在此基础上,建立了Carius管溶样-四氯化碳萃取分离Os-"钽试剂"萃取分离Re以及同位素稀释电感耦合等离子体质谱法测定的分析流程。利用该分析流程,对辉钼矿标准物质JDC进行Re-Os同位素年龄测定研究,测得其Re、Os的平均含量及年龄分别为(17.6±0.2)μg/g、(25.9±0.3)ng/g和(140.1±2.4)Ma,该结果在误差范围内与标准参考值一致。与目前常用的辉钼矿Re-Os同位素定年方法相比,该方法具有操作简便、快速、高效以及成本低的优势,非常适合作为辉钼矿Re-Os同位素定年的化学分离常规方法。

电子探针化学测年技术及其在地学中的应用

主要对电子探针化学测年技术的基本原理及其相关技术作一介绍。并以其在地学中的具体应用 ,如对独居石、锆石的化学测年 ,证明它是一种分析快速、测试容易的技术 ,与传统的同位素法测得的年龄具可比性。此项技术对矿石的来源、不同矿物的不同环带、不同世代的成分演化乃至时间演化均可进行分析 ,并可使年龄数据点与成分数据严格对应 ,而且测试所需的样品量少 ,可进行单颗粒的测定。因此 ,当某些岩体的被测矿物有捕虏体成因、岩浆成因、地幔成因等各种来源时 ,可分别求出某单一事件的年龄。另外 ,利用碎屑独居石的 w( Pb O) /w( Th O*2 )比值来确定碎屑岩的源岩是一种新的方法 。

SigmaPlot软件在化学实验数据处理中的应用

SigmaPlot是功能强大的数据分析和科学绘图软件,通过实例,初步介绍了SigmaPlot处理实验数据的方法和结果。结果表明,用SigmaPlot对实验数据作处理,解决了化学实验中数据多、处理麻烦、手工作图误差大等问题,使处理过程简单、快捷,提高了效率和准确性。