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| 1 | Recent glacial retreat in High Asia in China and its impact on water resource in Northwest China显示文摘Under the impact of climatic warming, the glaciers in the High Asia in China have been retreating continuously with negative glacial mass balance in recent several decades. The retreat became more intensive in the past 10 years. The spatial pattern of the glacial retreat in the High Asia in China is that the smallest magnitude of retreat is in the inland of the Tibetan Plateau, the magnitude increases from the inland to the margin of the Tibetan Plateau, and the largest magnitude at the margin of the Tibetan Plateau. The glacial retreat in the High Asia in China has an important impact on the water resource of the arid regions in Northwest China. This study shows that the glacial retreat in the 1990s has caused an increase of 5.5% in river runoff in Northwest China. In the Tarim River basin, the increase of river runoff is higher than 5.5%. | YAO Tandong 1,2 ,WANG Youqing 2 ,LIU Shiying 2,1 ,PU Jianchen 2,1 ,SHEN Yongping 2 & LU Anxin 2,1 1.Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100029,China 2.Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences,Lanzhou 730000,China | 2004 | Science China Earth Sciences2004,47,12: | 117 |
| 2 | Phase stability in high entropy alloys:Formation of solid-solution phase or amorphous phase | Sheng GUO C.T. LIU | 2011 | Progress in Natural Science:Materials International2011,21,6: | 91 |
| 3 | THE EAST ASIA/PACIFIC PATTERN TELECONNECTION OF SUMMER CIRCULATION AND CLIMATE ANOMALY IN EAST ASIA显示文摘In this paper,many observations show that the thermal states including the SST,the convective activities in the west-ern Pacific warm pool largely influence the interannual and intraseasonal variations of summer circulation and the cli-mate anomalies in East Asia.Moreover,it is pointed out that there is a teleconnection pattern of summer circulationanomalies in the Northern Hemisphere,the so-called East Asia/Pacific pattern.The cause of the teleconnection pattern is studied by using the theory of quasi-stationary planetary wave propaga-tion,and it may be due to the propagation of quasi-stationary planetary waves forced by heat source around thePhilippines.Moreover,this pattern is well simulated by using a quasi-geostrophic,linear,spherical model and theIAP-GCM,respectively. | 黄荣辉 | 1992 | Acta meteorologica Sinica1992,6,1: | 58 |
| 4 | 造山带中成对出现的高压麻粒岩与榴辉岩及其地球动力学意义显示文摘在一些典型碰撞造山带中,高压麻粒岩与榴辉岩在空间和时间上密切相关,它们之间的关系对揭示碰撞造山带的造山过程和造山机制具有重要意义。本文以中国西部的南阿尔金、柴北缘及中部的北秦岭造山带为例,详细陈述了这3个地区榴辉岩和相关的高压麻粒岩的野外关系、变质演化和形成时代,目的是要建立大陆碰撞造山带中榴辉岩和相关高压麻粒岩形成的地球动力学背景模式。南阿尔金榴辉岩呈近东西向分布在江尕勒萨依-玉石矿沟一带,与含夕线石副片麻岩、花岗质片麻岩和少量大理岩构成榴辉岩-片麻岩单元,榴辉岩中含有柯石英假象,其峰期变质条件为P=2.8~3.0GPa,T=730~850℃,并在抬升过程中经历了角闪岩-麻粒岩相的叠加;大量年代学研究显示其峰期变质时代为485~500Ma。南阿尔金高压麻粒岩分布在巴什瓦克地区,包括高压基性麻粒岩和高压长英质麻粒岩,它们与超基性岩构成了一个大约5km宽的构造岩石单元,与周围角闪岩相的片麻岩为韧性剪切带接触。长英质麻粒岩和基性麻粒岩的峰期组合均具有蓝晶石和三元长石(已变成条纹长石),形成的温压条件为T=930~1020℃,P=1.8~2.5GPa,并在退变质过程中经历了中压麻粒岩相变质作用叠加。锆石SHRIMP测定显示巴什瓦克高压麻粒岩的峰期变质时代为493~497Ma。都兰地区的榴辉岩分布柴北缘HP-UHP变质带的东端,在榴辉岩和围岩副片麻岩中均发现有柯石英保存,形成的峰期温压条件为T=670~730℃和,P=2.7~3.25GPa,退变质阶段经过了角闪岩相的叠加;榴辉岩相变质时代为420~450Ma。都兰地区的高压麻粒岩分布在阿尔茨托山西部,高压麻粒岩包括基性麻粒岩长英质麻粒岩,基性麻粒岩的峰期矿物组合为Crt+Cpx+Pl±Ky±Zo+Rt±Qtz,长英质麻粒岩的峰期矿物组合为:Grt+Kf+Ky+Pl+Qtz。峰期变质条件为T=800~925℃,P=1.4~1.85GPa,退变质阶段经历了角闪岩-绿片岩的改造,高压麻粒岩的变质时代为420~450Ma。北秦岭榴辉岩分布在官坡-双槐树一带,榴辉岩的峰期变质组合为Grt+Omp±Phe+Qtz+Rt,所计算的峰期温压条件为T=680~770℃和P=2.25~2.65GPa,年代学数据显示榴辉岩的变质时代为500Ma左右。北秦岭高压麻粒岩分布在含榴辉岩单元的南侧松树沟一带,包括高压基性麻粒岩和高压长英质麻粒岩,与超基性岩在空间上密切伴生,高压麻粒岩的峰期温压条件为T=850~925℃,P=1.45~1.80GPa,锆石U-Pb年代学研究显示其峰期变质时代为485~507Ma。以上三个实例显示,出现在同一造山带、在空间上伴生的高压麻粒岩和榴辉岩有各自不同的变质演化历史,但榴辉岩中的榴辉岩相变质时代和相邻的高压麻粒岩中的高压麻粒岩相变质作用时代相同或相近,这种成对出现的榴辉岩和高压麻粒岩代表了它们同时形成在造山带中不同的构造环境中,即榴辉岩的形成于大陆俯冲带中,而高压麻粒岩可能形成在俯冲带之上增厚的大陆地壳根部。 | 张建新 于胜尧 孟繁聪 李金平 | 2009 | 岩石学报2009,25,9: | 46 |
| 5 | 东准噶尔卡拉麦里地区黄羊山花岗岩和包体LA-ICP-MS锆石U-Pb测年及地质意义显示文摘高精度LA-ICP-MS锆石U-Pb测年结果表明,黄羊山岩浆混合花岗岩加权平均^(206)Pb/^(238)U年龄为311±12Ma,首次获得闪长质微细粒包体加权平均^(206)Pb/^(238)U年龄为300±6Ma,在误差范围内完全一致,均属于晚石炭世,前者代表黄羊山岩浆混合花岗岩成岩年龄,后者代表暗色闪长质微粒包体的形成年龄,表明两者是同时代形成的,属于300Ma前后准噶尔周边地区后碰撞岩浆活动的产物。岩石地球化学研究表明,寄主岩石具有高硅、低铝、贫钙镁、富碱和高分异的特征,寄主岩石、包体和辉绿岩脉成分均落在了混合趋势线上,寄主岩富集Rb和Th等大离子亲石元素及Zr、Hf等高场强元素,亏损Ba、Sr、Ta和Ti等元素,δEu值(为0.01)极低,具有低的^(87)Sr/^(86)Sr初始比值和高正的ε_(Nd)(t)值。黄羊山碱性花岗岩是在后碰撞拉张的构造背景下,幔源岩浆发生底垫作用,由于幔源岩浆底垫作用,下地壳温度升高而熔融形成酸性壳源岩浆,部分幔源岩浆沿着地壳中的深断裂带上涌,发生不同程度壳幔混合形成的,其中闪长质微细粒包体就是基性的幔源岩浆和酸性的壳源岩浆不同程度的混合的记录者,研究区的辉绿岩脉是幔源岩浆直接分异演化的产物。 | 杨高学 李永军 吴宏恩 司国辉 金朝 张永智 | 2009 | 岩石学报2009,25,12: | 46 |
| 6 | Amplitude of climatic changes in Qinghai-Tibetan Plateau显示文摘On the basis of ice core and meteorological data from the Qinghai-Tibetan (Q-l) Plateau, this article focuses on the discussion of the problems related to the sensitivity of temporal and spatial changes of the climate in high-altitude regions, particularly in the Q-T Plateau. The features of abrupt climatic changes of the past 100 ka, 2 000 a and recent years indicate that the amplitude of these changes in the Q-T Plateau was obviously larger than that in low-altitude regions. The scope of temperature change above 6 000 m in the Q-T Plateau between glacial and interglacial stages could reach over 10C℃, but only about 4℃ in low-elevation regions close to sea level. During the last 2 000 a, the amplitude of temperature changes at Guliya (over 6 000 m a.s.l.) in the Q-T Plateau reached 7℃, in comparison with 2℃ in eastern China at low altitude. In the present age, apparent differences of climatic warming have been observed in the Q-T Plateau, indicating that the warming in high-elevation regions is | YAO Tandong LIU Xiaodong WANG Ninglian SHI Yafeng | 2000 | Chinese Science Bulletin2000,45,13: | 47 |
| 7 | Clinical application of DNA ploidy to cervical cancer screening: A review显示文摘Screening for cervical cancer with DNA ploidy assessment by automated quantitative image cytometry has spread throughout China over the past decade and now an estimated 1 million tests per year are done there. Compared to conventional liquid based cytology, DNA ploidy has competitive accuracy with much higher throughput per technician. DNA ploidy has the enormous advantage that it is an objective technology that can be taught in typically 2 or 3 wk, unlike qualitative cytology, and so it can enable screening in places that lack sufficient qualified cytotechnologists and cytopathologists for conventional cytology. Most papers on experience with application of the technology to cervical cancer screening over the past decade were published in the Chinese language. This review aims to provide a consistent framework for analysis of screening data and to summarize some of the work published from 2005 to the end of 2013. Of particular interest are a few studies comparing DNA ploidy with testing for high risk human papilloma virus(hrH PV) which suggest that DNA ploidy is at least equivalent, easier and less expensive than hrH PV testing. There may also be patient management benefits to combining hr HPV testing with DNA ploidy. Some knowledge gaps are identified and some suggestions are made for future research directions. | David Garner | 2014 | World Journal of Clinical Oncology2014,5,5: | 43 |
| 8 | 太行山南段符山高镁闪长岩的成因——拆沉陆壳物质熔融的熔体与地幔橄榄岩反应的结果显示文摘本文对太行山南段符山高镁闪长岩进行了年代学与地球化学研究,结合其中地幔橄榄岩包体的研究,对符山高镁闪长岩的成因和中生代岩石圈地幔的性质进行了探讨。研究表明,符山闪长岩体是由一套含橄榄石角闪闪长岩-角闪闪长岩-闪长岩构成。含橄榄岩包体的寄主岩——角闪闪长岩中的锆石可划分为两种:一是代表寄主岩浆结晶的锆石:内部结构均匀、呈条带状吸收、自形-半自形晶形,具有较高的Th/U比值(1.10~4.08),其^(206)Pb/^(238)U年龄介于123~128Ma之间,12个点的加权平均值为125±1Ma,这表明岩体的形成时代为早白垩世;二是捕获或继承锆石:具有核边结构、吸收程度不均匀、呈浑圆状和自形-半自形两种,它们的Th/U比值介于0.32~2.03之间,构成了3组^(207)Pb/^(206)Pb加权平均年龄:2503±11Ma、2181±26Ma和1778±36Ma。该类岩石的SiO_2和MgO含量分别介于56.69%~59.21%和3.60%~6.33%之间;且以高Mg~#(0.51~0.64)、富Na(Na_2O/K_2O大于1)、高Cr(93.1×10^(-6)~420×10^(-6))、Ni(35.1×10^(-6)~137×10^(-6))为特征。该类岩石强烈富集轻稀土元素和大离子亲石元素、明显亏损高场强元素,(^(87)Sr/^(86)Sr)_i、ε_(Nd)(t)值和(^(206)Pb/^(204)Pb)_i分别变化于0.70581~0.70641、-8.30~-16.56和17.052~17.512之间。综合上述特征,同时结合地慢橄榄岩包体的特征和古元古代捕获锆石的大量存在,认为符山高镁闪长岩的原始岩浆起源于拆沉陆壳物质的部分熔融,其后经历了与地幔橄榄岩的反应过程。 | 许文良 杨德彬 裴福萍 于洋 | 2009 | 岩石学报2009,25,8: | 39 |
| 9 | 藏北羌塘中部绒玛地区蓝片岩岩石学、矿物学和^(40)Ar/^(39)Ar年代学显示文摘藏北羌塘中部沿龙木错-双湖-线出露一条低温高压变质带,目前已有多处蓝片岩的报道。然而,除冈玛错地区产有典型的蓝闪石外,多数地区并没有典型蓝闪石的报道。绒玛蓝片岩位于羌塘中部高压变质带的中段,是该带中规模最大、保存最好的蓝片岩,对蓝片岩进行了详细的岩石学和矿物学研究,钠质角闪石主要为蓝闪石、青铝闪石、钠闪石和镁钠闪石。对蓝片岩中蓝闪石和多硅白云母进行了^(40)Ar/^(39)Ar定年,获得了227.3±3.8Ma和215±1.5Ma的坪年龄,分别代表蓝片岩快速俯冲消减和俯冲作用结束开始折返抬升的时代。绒玛蓝片岩岩石学、矿物学和^(40)Ar/^(39)Ar年代学研究为羌塘中部高压变质带的研究提供了新的资料。 | 翟庆国 李才 王军 陈文 张彦 | 2009 | 岩石学报2009,25,9: | 38 |
| 10 | 多壁碳纳米管固相萃取净化-高效液相色谱法测定猪肉和鸡肉中的磺胺多残留显示文摘建立了多壁碳纳米管为吸附剂的固相萃取净化-高效液相色谱-紫外检测测定猪肉和鸡肉中多种磺胺类药物多残留的方法。样品采用乙腈提取,多壁碳纳米管固相萃取净化,NaH2PO4缓冲溶液(pH5.5~6.0)溶解上样,5%(v/v)丙酮-正己烷淋洗,丙酮-二氯甲烷(1:1,v/v)洗脱。色谱分离以50mmol/LNaH2PO4-乙腈(7:3,v/v)为流动相,方法的线性范围为0.01~1.00mg/L,线性相关系数大于0.998,检出限(LOD)为0.003mg/L,定量限(LOQ)为0.01mg/L。在0.02~0.2mg/kg添加范围内,9种磺胺类药物的回收率高于70%,RSD低于8%,表明多壁碳纳米管对磺胺类药物具有较强的吸附富集能力。该方法简便、准确可用于动物组织及产品中磺胺药物残留的检测。 | 赵海香 刘海萍 闫早婴 | 2014 | 色谱2014,32,3: | 40 |
| 11 | Achieving over 16% efficiency for single-junction organic solar cells显示文摘To achieve high photovoltaic performance of bulk hetero-junction organic solar cells(OSCs), a range of critical factors including absorption profiles, energy level alignment, charge carrier mobility and miscibility of donor and acceptor materials should be carefully considered. For electron-donating materials, the deep highest occupied molecular orbital(HOMO) energy level that is beneficial for high open-circuit voltage is much appreciated. However, a new issue in charge transfer emerges when matching such a donor with an acceptor that has a shallower HOMO energy level. More to this point, the chemical strategies used to enhance the absorption coefficient of acceptors may lead to increased molecular crystallinity, and thus result in less controllable phase-separation of photoactive layer. Therefore, to realize balanced photovoltaic parameters, the donor-acceptor combinations should simultaneously address the absorption spectra, energy levels, and film morphologies. Here, we selected two non-fullerene acceptors, namely BTPT-4F and BTPTT-4F, to match with a wide-bandgap polymer donor P2F-EHp consisting of an imidefunctionalized benzotriazole moiety, as these materials presented complementary absorption and well-matched energy levels. By delicately optimizing the blend film morphology, we demonstrated an unprecedented power conversion efficiency of over 16% for the device based on P2F-EHp:BTPTT-4F, suggesting the great promise of materials matching toward high-performance OSCs. | Baobing Fan Difei Zhang Meijing Li Wenkai Zhong Zhaomiyi Zeng Lei Ying Fei Huang Yong Cao | 2019 | Science China Chemistry2019,62,6: | 38 |
| 12 | Study of the High Pressure Metamorphic Blueschist and Its Late Proterozoic Age in the Eastern Jiangnan Belt显示文摘Several blueschist outcrops, specially glaucophane-bearing ones, were found in Dexing, eastern Jiangnan belt. The latest researches suggest that the blueschists distributed in the Late Proterozoic ophiolite melange blocks of the northeastern Jiangxi fault zone between the Jiuling tectonic region and the Huaiyu tectonic region of volcanic are that is located near the frontier of Jiangxi, Zhejiang and Anhui provinces (Fig. 1). | 舒良树 周国庆 施央申 殷俊 | 1994 | Chinese Science Bulletin1994,39,14: | 32 |
| 13 | 超高效液相色谱-线性离子阱/静电场轨道阱高分辨质谱快速筛查化妆品中的24种激素显示文摘建立了超高效液相色谱-线性离子阱/静电场轨道阱组合式高分辨质谱联用(UPLC-LTQ/Orbitrap MS)快速筛查、定性识别化妆品中24种激素的分析方法。不同剂型的化妆品样品经甲醇超声提取,用Waters ACQUITY UPLC BEH C18色谱柱(50 mm×2.1 mm,1.7μm)分离,以乙腈和0.1%(v/v)甲酸水溶液为流动相进行梯度洗脱。通过静电场轨道阱全扫描得到激素化合物的准分子离子的精确质量数,实现对化妆品中激素的快速筛查;再以保留时间和数据依赖扫描(data dependent scan)模式获得的子离子质谱图进行定性确证。24种激素化合物的质量准确度误差小于3×10-6(3 ppm);线性良好,相关系数大于0.99;检出限≤10μg/kg(S/N=3),能满足实际化妆品样品的分析要求。应用该方法对不同剂型的50余种化妆品样品进行筛查分析,结果良好。该方法是化妆品中激素快速筛查、定性识别的有效方法。 | 李兆永 王凤美 牛增元 罗忻 张罡 陈军辉 | 2014 | 色谱2014,32,5: | 33 |
| 14 | Maize-soybean strip intercropping: Achieved a balance between high productivity and sustainability显示文摘Intercropping is one of the most vital practice to improve land utilization rate in China that has limited arable land resource. However, the traditional intercropping systems have many disadvantages including illogical field lay-out of crops, low economic value, and labor deficiency, which cannot balance the crop production and agricultural sustainability. In view of this, we developed a novel soybean strip intercropping model using maize as the partner, the regular maize-soybean strip intercropping mainly popularized in northern China and maize-soybean relay-strip intercropping principally extended in southwestern China. Compared to the traditional maize-soybean intercropping systems, the main innovation of field lay-out style in our present intercropping systems is that the distance of two adjacent maize rows are shrunk as a narrow strip, and a strip called wide strip between two adjacent narrow strips is expanded reserving for the growth of two or three rows of soybean plants. The distance between outer rows of maize and soybean strips are expanded enough for light use efficiency improvement and tractors working in the soybean strips. Importantly, optimal cultivar screening and increase of plant density achieved a high yield of both the two crops in the intercropping systems and increased land equivalent ratio as high as 2.2. Annually alternative rotation of the adjacent maize-and soybean-strips increased the grain yield of next seasonal maize, improved the absorption of nitrogen, phosphorus, and potasium of maize, while prevented the continuous cropping obstacles. Extra soybean production was obtained without affecting maize yield in our strip intercropping systems, which balanced the high crop production and agricultural sustainability. | DU Jun-bo HAN Tian-fu GAI Jun-yi YONG Tai-wen SUN Xin WANG Xiao-chun YANG Feng LIU Jiang SHU Kai LIU Wei-guo YANG Wen-yu | 2018 | Journal of Integrative Agriculture2018,17,4: | 34 |
| 15 | High intensity focused ultrasound in clinical tumor ablation显示文摘Recent advances in high intensity focused ultrasound(HIFU),which was developed in the 1940s as a viable thermal tissue ablation approach,have increased its popularity.In clinics,HIFU has been applied to treat a variety of solid malignant tumors in a well-defined volume,including the pancreas,liver,prostate,breast,uterine fibroids,and soft-tissue sarcomas.In comparison to conventional tumor/cancer treatment modalities,such as open surgery,radio-and chemo-therapy,HIFU has the advantages of non-invasion,non-ionization,and fewer complications after treatment.Over 100 000 cases have been treated throughout the world with great success.The fundamental principles of HIFU ablation are coagulative thermal necrosis due to the absorption of ultrasound energy during transmission in tissue and the induced cavitation damage.This paper reviews the clinical outcomes of HIFU ablation for applicable cancers,and then summarizes the recommendations for a satisfactory HIFU treatment according to clinical experience.In addition,the current challenges in HIFU for engineers and physicians are also included.More recent horizons have broadened the application of HIFU in tumor treatment,such as HIFU-mediated drug delivery,vessel occlusion,and soft tissue erosion(“histotripsy”).In summary,HIFU is likely to play a significant role in the future oncology practice. | Yu-Feng Zhou | 2011 | World Journal of Clinical Oncology2011,2,1: | 33 |
| 16 | Experimental study on the mechanical properties of rocks at high temperature显示文摘The mechanical properties of marble, limestone, and sandstone as well as the stress-strain curve, the varying characteristics of the peak strength, the peak strain and elastic modulus were studied by using the MTS810 Rock Mechanics Servo-controlled Testing System under the action of temperatures rang- ing from room temperature to 800℃ . Results show that (1) the peak strength and elastic modulus of marble fluctuate at the temperature from normal to 400 ℃ ; and they decrease gradually over 400℃ . (2) With the rise of the temperature, the peak strength and elastic modulus of limestone show downward trend from normal temperature to 200 ℃ ; have little change from 200 ℃ to 600 ℃; and decrease sharply over 600 ℃ . (3) The peak strength of sandstone shows a downward trend while a little change for elastic modulus at normal temperature to 200 ℃ ; and from 200 ℃ to 600 ℃ , the peak strength of sandstone in- creases while a little change for elastic modulus; the peak strength and elastic modulus decrease rap- idly at the temperature over 600 ℃ . (4) The peak strain of limestone shows little change at normal tem- perature to 600 ℃ , however, the peak strain increases rapidly over 600 ℃; and for marble and sandstone, the peak strain decreases with the rise of the temperature from normal temperature to 200℃ , the peak strain increases rapidly over 200℃. The result can provide valuable references for the rock engineering design at high temperature. | ZHANG LianYing MAO XianBiao LU AiHong | 2009 | Science China(Technological Sciences)2009,52,3: | 30 |
| 17 | PHYSICAL MODELING FOR THE MECHANISMS OF BEAD FORMATION DEFECTS BASED ON THE STABILITY OF LIQUID METAL显示文摘Based on the theory of stability of the liquid metal under the action of surface tension,a physical mod- el is established for the mechanisms of the bead formation deferct’ humping’, which is generated during high - speed welding.A boundary function is introduced to correct the model,theoretical results got by the model correspond well with the experimental phenomena. A two - dimensional conducting model is adoopted in the simulation of the temperature field during high - speed welding.Finally, the factors acting upon the stability of liquid metal are analyzed. | S. Y. Yin L. Feng J. Z. Ding and S. J. Chan( 1) Beijing Polytechnic University, Beijing 100022, China 2) National Key Laboratory of Advanced Wdlding Production Technology, HIT, Harbin 150001, China) | 2000 | Acta Metallurgica Sinica(English Letters)2000,13,1: | 28 |
| 18 | Improvement of tree-like network constructal method for heat conduction optimization显示文摘The analysis of the “tree-like network” construct method has been repeated. The high effective conduction channel distribution has been optimized again, without the premise that the new order assembly construct must be assembled by the optimized last order construct. It is proved that the “tree-like network” construct method is faultiness. A more optimal construct is obtained, and when the thermal conductivity and the proportion of the two heat conduction materials are constant, the limit of the minimum heat resistance is derived. All these conclusions can be used to guide the engineering application. | WU Wenjun CHEN Lingen SUN Fengrui | 2006 | Science China(Technological Sciences)2006,49,3: | 25 |
| 19 | 南秦岭大堡组奥陶纪洋岛玄武岩的识别及其构造意义:来自地球化学和年代学证据显示文摘秦岭造山带以商-丹构造带为界分为北秦岭和南秦岭构造带。大堡组位于南秦岭构造带内,由灰色-深灰色的泥岩、粉砂岩和炭硅板岩,以及夹含炭硅质岩、灰岩和基性火山岩块体组成。在大堡组中出露的能干上和蚂蝗峡基性岩块夹于黑色的泥岩之中,岩石地球化学分析结果表明,SiO_2含量为41.53%~53.59%,富TiO_2为2.14%~3.58%,REE的总量为∑REE=282.3×10^(-6),轻稀土元素较重稀土元素富集[(La/Yb)_N=8.34],略显Eu正异常(Eu~*=1.13~1.25),具有较高的Ti/Y(300~622)和Zr/Y(3.8~7.4)比值。大离子亲石元素Rb、Ba和K相对富集,无明显的Nb和Ta异常,其Nb和Ta值为N-MORB标准值的10~20倍,为典型洋岛玄武岩(OIB)地球化学特征。锆石SHRIMPⅡU-Pb测年获得能干上和蚂蝗峡基性岩块体分别形成于446Ma和455Ma。这些资料进一步表明,奥陶纪时期南秦岭存在着古洋盆。 | 王涛 王宗起 闫臻 闫全人 张英利 向忠金 | 2009 | 岩石学报2009,25,12: | 25 |
| 20 | Study on real working performance and overload safety factor of high arch dam显示文摘Considering the fact that high arch dams have problems such as complicated stress,high cost,and hazards after being damaged,this paper intends to study the effects of load,material strength,and safety analysis method on dam safety and working performance of arch dams.In this article,the effects of temperature,self weight exaction way and water loading on structure response are first discussed,and a more reasonable way of considering is then put forward.By taking into consideration the mechanical property of materials and comparing the effects of different yield criteria on overloading safety of high arch dams,this paper concludes that brittle characteristics of concrete should be fully considered when conducting safety assessment for high arch dams to avoid overestimating the bearing capacity of the dams.By comparing several typical projects,this paper works out a safety assessment system of multiple safety and relevant engineering analogical analysis methods,which is closer to the actual situation,and thus is able to assess the response of high arch dam structure in a more comprehensive way,elicit the safety coefficients in different situations,and provide a new way of considering the safety assessment of high arch dams. | ZHANG GuoXin,LIU Yi & ZHOU QiuJing Department of Structures and Materials,China Institute of Water Resources and Hydropower Research,Beijing 100038,China | 2008 | Science China(Technological Sciences)2008,51,S2: | 25 |