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The transport of water in subduction zones

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Science China Earth Sciences 2016年第4期59卷 651-682页

作者： ZHENG YongFei CHEN RenXu XU Zheng zhang shaobing School of Earth and Space Sciences University of Science and Technology of China

The transport of water from subducting crust into the mantle is mainly dictated by the stability of hydrous minerals in subduction zones. The thermal structure of subduction zones is a key to dehydration of the subducting crust at different depths. Oceanic subduction zones show a large variation in the geotherm, but seismicity and arc volcanism are only prominent in cold subduction zones where geothermal gradients are low. In contrast, continental subduction zones have low geothermal gradients, resulting in metamorphism in cold subduction zones and the absence of arc volcanism during subduction. In very cold subduction zone where the geothermal gradient is very low(?5?C/km), lawsonite may carry water into great depths of ?300 km. In the hot subduction zone where the geothermal gradient is high(>25?C/km), the subducting crust dehydrates significantly at shallow depths and may partially melt at depths of <80 km to form felsic melts, into which water is highly dissolved. In this case, only a minor amount of water can be transported into great depths. A number of intermediate modes are present between these two end-member dehydration modes, making subduction-zone dehydration various. Low-T/low-P hydrous minerals are not stable in warm subduction zones with increasing subduction depths and thus break down at forearc depths of ?60–80 km to release large amounts of water. In contrast, the low-T/low-P hydrous minerals are replaced by low-T/high-P hydrous minerals in cold subduction zones with increasing subduction depths, allowing the water to be transported to subarc depths of 80–160 km. In either case, dehydration reactions not only trigger seismicity in the subducting crust but also cause hydration of the mantle wedge. Nevertheless, there are still minor amounts of water to be transported by ultrahigh-pressure hydrous minerals and nominally anhydrous minerals into the deeper mantle. The mantle wedge overlying the subducting slab does not partially melt upon water influx

关键词： Subduction zones Oceanic crust Mantle wedge Thermal structure Hydrous minerals Water transport Arc magmatism

SHRIMP zircon U-Pb dating for two episodes of migmatization in the Dabie orogen

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Chinese Science Bulletin 2007年第13期52卷 1836-1842页

作者： WU YuanBao TANG Jun zhang shaobing ZHAO ZiFu State Key Laboratory of Geological Processes and Mineral Resources Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China CAS Key Laboratory of Crust-Mantle Materials and Environments School of Earth and Space Sciences University of Science and Technology of China Hefei 230026 China Beijing SHRIMP Center Chinese Academy of Geological Sciences Beijing 100037 China

Zircon CL imaging and SHRIMP U-Pb dating were carried out for migmatite in the Dabie orogen. Zircons from the Manshuihe migmatite show clear core-rim structures. The cores display sector or weak zoning and low Th/U ratios of 0.01 to 0.17, indicating their precipitation from metamorphic fluid. They yield a weighted mean age of 137±5 Ma. By contrast, the rims exhibit planar or nebulous zoning with relatively high Th/U ratios of 0.35 to 0.69, suggesting their growth from metamorphic melt. They give a weighted mean age of 124±2 Ma. Zircons from the Fenghuangguan migmatite also display core-rim structures. The cores are weakly oscillatory zoned or unzoned with high Th/U ratios of 0.21 to 3.03, representing inherited zircons of magmatic origin that experienced different degrees of solid-state recrystallization. SHRIMP U-Pb analyses obtain that its protolith was emplaced at 768±12 Ma, consistent with middle Neoproterozoic ages for protoliths of most UHP metaigneous rocks in the Dabie-Sulu orogenic belt. By contrast, the rims do not show significant zoning and have very low Th/U ratios of 0.01 to 0.09, typical of zircon crystallized from metamorphic fluid. They yield a weighted 206Pb/238U age of 137±4 Ma. Taking the two case dates together, it appears that there are two episodes of zircon growth and thus migmati-tization at 137±2 Ma and 124±2 Ma, respectively, due to metamorphic dehydration and partial melting. The appearance of metamorphic dehydration corresponds to the beginning of tectonic extension thus to the tectonic switch from crustal compression to extension in the Dabie orogen. On the other hand, the partial melting is responsible for the extensional climax, resulting in formation of coeval migmatite, granitoid and granulite. They share the common protolith, the collision-thickened continental crust of mid-Neoproterozoic ages.

关键词：混合岩锆石脱水处理溶解作用

Multifunctional N,S-doped and methionine functionalized carbon dots for on−off−on Fe^(3+)and ascorbic acid sensing,cell imaging,and fluorescent ink applying

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Nano Research 2023年第4期16卷 5401-5411页

作者： Zheng Yang Tiantian Xu shaobing zhang Hui Li Yali Ji Xiaodan Jia Jianli Li Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education College of Chemistry&Materials ScienceNorthwest UniversityXi’an 710127China College of Chemistry and Chemical Engineering Xi’an University of Science and TechnologyXi’an 710054China Key Laboratory of Coal Resources Exploration and Comprehensive Utilization Ministry of Land and ResourcesXi’an 710012China

Fluorescent carbon dots(CDs)have been identified as potential nanosensors and attracted tremendous research interests in wide areas including anti-counterfeiting,environmental and biological sensing and imaging in considering of the attractive optical *** this work,we present a CDs based fluorescent sensor from polyvinylpyrrolidone,citric acid,and methionine as precursors by hydrothermal *** selective quantifying of Fe^(3+)and ascorbic acid(AA)are based on the fluorescent on-off-on process,in which the fluorescent quenching is induced by the coordination of the Fe^(3+)on the surface of the CDs,while the fluorescence recovery is mainly attributed to redox reaction between Fe^(3+)and AA,breaking the coordination and bringing the fluorescence *** by the good water solubility and biocompatibility,significant photostability,superior photobleaching resistance as well as high selectivity,sensitivity,and interference immunity,which are constructed mainly from the N,S-doping and methionine surface functionalization,the CDs have not only been employed as fluorescence ink in multiple anticounterfeiting printing and confidential document writing or transmitting,but also been developed as promising fluorescence sensors in solution and solid by CDs doped test strips and hydrogels for effectively monitoring and removing of Fe^(3+)and AA in environmental aqueous *** CDs have been also implemented as effective diagnostic candidates for imaging and tracking of Fe^(3+)and AA in living cells,accelerating the understanding of their function and importance in related biological processes for the prevention and treatment specific diseases.

关键词： carbon dots fluorescent sensors Fe^(3+) ascorbic acid fluorescent ink message encryption

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水酶法从菜籽中提取油及水解蛋白的研究

农业工程学报 2007年第9期23卷 213-219页

作者：章绍兵王璋江南大学食品科学与安全教育部重点实验室无锡214036

为了同时从菜籽中提取清油和水解蛋白,依次使用复合细胞壁多糖酶和碱性蛋白酶（Alcalase 2.4 L）水解湿磨菜籽浆,并利用大孔吸附树脂纯化水解蛋白液.结果表明：经过酶解（复合细胞壁多糖酶：浓度3%（v/w）,pH 5.0,48℃,5 h;Alcalase 2.... 详细信息

为了同时从菜籽中提取清油和水解蛋白,依次使用复合细胞壁多糖酶和碱性蛋白酶（Alcalase 2.4 L）水解湿磨菜籽浆,并利用大孔吸附树脂纯化水解蛋白液.结果表明：经过酶解（复合细胞壁多糖酶：浓度3%（v/w）,pH 5.0,48℃,5 h;Alcalase 2.4 L：浓度1.5%（v/w）,初始pH 9.0,60℃,3 h）、洗渣和破乳后总菜籽清油提取率为88%～90%,总水解蛋白提取率为93%～95%.和溶剂萃取油相比,水酶法提取油的酸价偏高,颜色略深,但过氧化值低,两者皂化价,碘价和脂肪酸组成均接近.菜籽水解蛋白分子量小于1500的组分约占96%,其中小于600的约占87%.经过大孔吸附树脂纯化后,菜籽肽中糖和灰分含量显著降低,硫苷和植酸均未检出.

关键词：水酶法油菜籽菜籽油菜籽水解蛋白油品质大孔吸附树脂

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水酶法提取菜籽乳化油的工艺研究

农业工程学报 2006年第11期22卷 250-253页

作者：章绍兵王璋江南大学食品科学与安全教育部重点实验室无锡214036

为获得温和的制油工艺,该文采用了多种细胞壁多糖酶制剂对湿磨菜籽浆进行水相酶解法提油。同时对菜籽内源硫苷酶的湿热灭活条件及硫苷的湿热稳定性进行了研究,并优化了酶解的工艺条件。结果表明沸水处理5min可以有效钝化菜籽内源硫苷酶... 详细信息

为获得温和的制油工艺,该文采用了多种细胞壁多糖酶制剂对湿磨菜籽浆进行水相酶解法提油。同时对菜籽内源硫苷酶的湿热灭活条件及硫苷的湿热稳定性进行了研究,并优化了酶解的工艺条件。结果表明沸水处理5min可以有效钝化菜籽内源硫苷酶,此时硫苷的降解率为11.28%;果胶酶、纤维素酶和β-葡聚糖酶经复配(4∶1∶1)后处理菜籽比单一酶制剂的作用效果好,复合酶解最适工艺条件为固液比1∶5,加酶量3%,酶解时间5h,在此条件下乳化油得率为92.45%。

关键词：水酶法菜籽油硫苷酶

扬子陆核的生长和再造:锆石U-Pb年龄和Hf同位素研究

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岩石学报 2007年第2期23卷 393-402页

作者：张少兵郑永飞中国科学技术大学地球和空间科学学院中国科学院壳幔物质与环境重点实验室合肥230026

对宜昌三峡附近崆岭杂岩中混合岩、片麻岩和变沉积岩以及莲沱砂岩进行了锆石U-Pb和Hf-O同位素研究,研究结果深化了我们对扬子陆核生长和再造的认识。在莲沱砂岩中发现了老达3.8Ga的碎屑锆石,说明扬子陆块可能存在这个年龄的地壳物质;其H... 详细信息

对宜昌三峡附近崆岭杂岩中混合岩、片麻岩和变沉积岩以及莲沱砂岩进行了锆石U-Pb和Hf-O同位素研究,研究结果深化了我们对扬子陆核生长和再造的认识。在莲沱砂岩中发现了老达3.8Ga的碎屑锆石,说明扬子陆块可能存在这个年龄的地壳物质;其Hf同位素组成指示初生地壳生长出现在4.0Ga。崆岭杂岩中混合岩和片麻岩的U-Pb年龄表明,在3.2～3.3Ga和2.9～3.0Ga有两期重要的岩浆活动,指示扬子陆核可能于中太古代就开始形成。锆石Hf同位素研究则指示,其原岩至少从3.5Ga就开始从亏损地幔分异出来。混合岩和变沉积岩中所记录的1.9～2.0Ga变质事件,是扬子陆核再造并发生克拉通化的主要时期。而广泛分布于扬子陆块周边的新元古代岩浆活动不仅导致了许多太古宙和古元古宙地壳重熔,而且引起了初生地壳的快速再造。

关键词：扬子陆块前寒武纪大陆生长与再造锆石U-Pb年龄锆石Hf同位素

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低δ^(18)O岩浆岩的成因

岩石学报 2011年第2期27卷 520-530页

作者：张少兵郑永飞中国科学院壳幔物质与环境重点实验室中国科学技术大学地球和空间科学学院合肥230026

具有显著低于正常幔源岩浆δ18O值的岩浆岩是地球上比较罕见的一种岩石,其形成需要特殊的岩浆过程。虽然岩浆分异过程基本上不改变氧同位素组成,但水岩反应可以明显改变岩石的氧同位素组成,高温水岩反应会导致岩石的氧同位素组成显著降... 详细信息

具有显著低于正常幔源岩浆δ18O值的岩浆岩是地球上比较罕见的一种岩石,其形成需要特殊的岩浆过程。虽然岩浆分异过程基本上不改变氧同位素组成,但水岩反应可以明显改变岩石的氧同位素组成,高温水岩反应会导致岩石的氧同位素组成显著降低,这得到了理论计算的支持。对黄石高原流纹岩和冰岛玄武岩这两个典型的低δ18O岩浆实例的长期研究发现,在地表遭受了高温热液蚀变的低δ18O岩石部分熔融或者被岩浆同化是形成低δ18O岩浆的重要机制,这通常通过裂谷构造带破火山口的垮塌来实现。塞舌尔和碾子山代表了结晶于低δ18O岩浆的花岗岩实例,其形成需要源区有亏损18O的地壳物质参与。大别-苏鲁造山带超高压变质岩亏损18O的幅度和这些亏损18O岩石的分布面积都非常令人瞩目。对这些超高压变质岩的原岩进行氧同位素研究,能够为其这些低δ18O岩石的成因提供有力的制约。目前已经在北淮阳花岗岩中报道了具有新元古代年龄和低δ18O值的锆石。研究显示,这些花岗岩可能经历了两次高温水岩反应,第一次导致了低18O岩浆的形成和低δ18O值锆石的结晶,第二次则进一步降低了其它矿物的δ18O值,导致了氧同位素不平衡。对这些低δ18O花岗岩的深入研究,特别是进行原位微区分析,不仅有助于我们深入认识低δ18O岩浆的形成机理,而且有助于进一步理解水岩反应中元素和同位素的地球化学行为。

关键词：低δ18O岩浆氧同位素水岩反应锆石

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pH值对水剂法提取花生蛋白凝胶特性的影响

河南工业大学学报（自然科学版） 2019年第5期40卷 53-58页

作者：李侠章绍兵河南工业大学粮油食品学院

采用水剂法提取花生蛋白,研究pH值对花生蛋白热致凝胶特性(凝胶硬度、持水性、动态流变性质、凝胶作用力)和部分结构性质(表面疏水性、游离巯基、内源荧光光谱)的影响。结果表明:pH值为3时花生蛋白凝胶具有最大的凝胶硬度、持水性和储... 详细信息

采用水剂法提取花生蛋白,研究pH值对花生蛋白热致凝胶特性(凝胶硬度、持水性、动态流变性质、凝胶作用力)和部分结构性质(表面疏水性、游离巯基、内源荧光光谱)的影响。结果表明:pH值为3时花生蛋白凝胶具有最大的凝胶硬度、持水性和储能模量;在中性和碱性范围内,pH值为8时花生蛋白凝胶的硬度、持水性和储能模量最高。花生蛋白凝胶溶解度测定结果表明,疏水相互作用在花生蛋白凝胶形成过程中发挥最主要的作用,二硫键其次。分析花生蛋白的结构性质可知,pH值为3时花生蛋白的表面疏水性和游离巯基含量最高,且花生蛋白内源荧光光谱发生了明显的红移;而在中性和碱性范围内,pH值为8时花生蛋白表面疏水性最强,游离巯基含量较高。

关键词：花生蛋白 pH值热致凝胶特性

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自旋式土层锚杆在西安地铁中的应用

城市轨道交通研究 2010年第1期13卷 66-69页

作者：张少兵西安市地下铁道有限责任公司西安工程师710016

自旋锚杆作为一种安全可靠、经济可行、快速简便且可回收复用的基坑支护新技术,已在深基坑开挖支护过程中得到应用。结合西安地铁2号线深基坑自旋锚杆支护技术的应用,介绍了自旋式锚杆的结构、锚固原理、工程特点,分析了自旋锚杆在地铁... 详细信息

自旋锚杆作为一种安全可靠、经济可行、快速简便且可回收复用的基坑支护新技术,已在深基坑开挖支护过程中得到应用。结合西安地铁2号线深基坑自旋锚杆支护技术的应用,介绍了自旋式锚杆的结构、锚固原理、工程特点,分析了自旋锚杆在地铁深基坑中的受力性能。通过试验锚杆计算值与实测值的对比分析,确定了自旋式锚杆的参数,为进一步研究深基坑自旋锚杆支护力学性能及稳定问题打下了良好的基础。

关键词：自旋式锚杆深基坑支护体系