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^(40)Ar/^(39)Ar ages and stable isotopes of supergene jarosite from the Baiyin VHMS ore field, NE Tibetan Plateau with paleoclimatic implications

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Chinese Science Bulletin 2014年第24期59卷 2999-3009页

作者： Lei Chen jianwei li State Key Laboratory of lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Faculty of Earth Resources China University of Geosciences

Supergene jarosite is widely distributed in weathering profiles derived from hypogene sulfide ores.Precise40Ar/39Ar dating and determination of hydrogen and oxygen isotopes of supergene jarosite can not only place tight constraints on the timing and history of continental weathering and supergene enrichment of sulfide ore deposits,but also shed significant insights into paleoclimatic conditions and tectonic uplift responsible for the weathering.In this paper,we present a preliminary study of40Ar/39Ar geochronology and stable isotope geochemistry of supergene jarosite from the early Paleozoic Zheyaoshan volcanic-hosted massive sulfide deposit of the Baiyin ore field located in the eastern portion of the Qilian Mountain along the northeastern(NE)margin of the Tibetan Plateau in an attempt to better understand the climatic conditions prevailed during the pervasive weathering in the region.jarosite from the Zheyaoshan mining area occurs either as gravels within alluvial deposits over low-relief flat-top hills or cm-wide veins crosscutting weathered sulfide ores or their wall rocks.The gravels consist of massive jarosite aggregates with tabular crystal morphology and contain 8.21 wt%–8.31 wt%K2O on average.Two jarosite grains extracted from the gravels(08-02-2 and 08-02-5)yield well-defined40Ar/39Ar plateauages of 37.1±0.3 and 41.2±0.4 Ma(2r),respectively.They have dD values of-133%and-156%,and d18OSO4values of 2.6%and 2.5%.The vein-type jarosite consists of hexagonal pyramid crystals and contains much lower K2O,averaging at 2.44 wt%–2.72 wt%.Two jarosite veins(06-16-3 and 06-16-4)yield similar plateau ages of 3.2±0.1 and 3.3±0.1 Ma(2r),respectively.These jarosite veins have dD values of-158%and-160%,and d18OSO4values of 2.8%and 2.5%.The40Ar/39Ar ages indicate that sulfide ores of the Zheyaoshan deposit must have been brought to the surface since the late Eocene,and subsequently subjected to prolonged oxidation and supergene enrichment.The precipitation and preservation of jarosite in weathering profiles indicate that

关键词：稳定同位素地球化学青藏高原东北边缘黄钾铁矾白银矿田古气候意义表生年龄 VHMS

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Ubiquitin-Specific Protease 14 （UBP14） Is Involved in Root Responses to Phosphate Deficiency in Arabidopsis

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Molecular Plant 2010年第1期3卷 212-223页

作者： Wen-Feng li Paula j. Perry Nulu N. Prafulla Wolfgang Schmidt Institute of Plant and Microbial Biology Academia Sinica 115 Taipei

A mutant isolated from a screen of EMS-mutagenized Arabidopsis lines, per1, showed normal root hair development under control conditions but displayed an inhibited root hair elongation phenotype upon Pi deficiency. Additionally, the per1 mutant exhibited a pleiotropic phenotype under control conditions, resembling Pi-deficient plants in several aspects. Inhibition of root hair elongation upon growth on low Pi media was reverted by treatment with the Pi analog phosphite, suggesting that the mutant phenotype is not caused by a lack of Pi. Reciprocal grafting experiments revealed that the mutant rootstock is sufficient to cause the phenotype. Complementation analyses showed that the PER1 gene encodes an ubiquitin-specific protease, UBP14. The mutation caused a synonymous substitution in the 12th exon of this gene, resulting in a lower abundance of the UBP14 protein, probably as a consequence of reduced translation efficiency. Transcriptional profiling of per1 and wild-type plants subjected to short-term Pi starvation revealed genes that may be important for the signaling of Pi deficiency. We conclude that UBP14 function is crucial for adapting root development to the prevailing local availability of phosphate.

关键词： Phosphate deficiency root hairs ubiquitin-specific protease root development.

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Macrophage polarization in response to wear particles in vitro

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Cellular & Molecular Immunology 2013年第6期10卷 471-482页

作者： joseph K Antonios Zhenyu Yao Chenguang li Allison j Rao Stuart B Goodman Orthopaedic Research Laboratories Department of Orthopaedic Surgery Stanford University School of Medicine Stanford CA USA

Total joint replacement is a highly successful surgical procedure for treatment of patients with disabling arthritis and joint dysfunction. However, over time, with high levels of activity and usage of the joint, implant wear particles are generated from the articulating surfaces. These wear particles can lead to activation of an inflammatory reaction, and subsequent bone resorption around the implant （periprosthetic osteolysis）. Cells of the monocyte/macrophage lineage orchestrate this chronic inflammatory response, which is dominated by a pro-inflammatory （M 1） macrophage phenotype rather than an anti-inflammatory pro-tissue healing （M2） macrophage phenotype. While it has been shown that interleukin-4 （IL-4） selectively polarizes macrophages towards an M2 anti-inflammatory phenotype which promotes bone healing, rather than inflammation, little is known about the time course in which this occurs or conditions in which repolarization through I L-4 is most effective. The goal of this work was to study the time course of murine macrophage polarization and cytokine release in response to challenge with combinations of polymethyl methacrylate （PMMA） particles, lipopolysaccharide （LPS） and IL-4 in vitro. Treatment of particle-challenged monocyte/macrophages with IL-4 led to an initial suppression of pro-inflammatory cytokines and inducible nitric oxide synthase （iNOS） production and subsequent polarization into an M2 anti-inflammatory phenotype. This result was optimized when IL-4 was delivered before PMMA particle challenge, to an M 1 phenotype rather than to uncommitted （MO） macrophages. The effects of this polarization were sustained over a 5-day time course. Polarization of M1 macrophages into an M2 phenotype may be a strategy to mitigate wear particle associated periprosthetic osteolysis.

关键词： IL-4 macrophage polarization osteolysis PMMA particles total joint replacement

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Two-way shape memory effect in a Ti-Zr-Nb-Ta high-temperature shape memory alloy

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Rare Metals 2024年第3期43卷 1257-1262页

作者： Cheng-Yang Xiong Tuo li jun Wang Yan li School of Materials Science and Engineering Beihang UniversityBeijing100191China

The two-way shape memory effect in a Ti-18.5Zr-10Nb-3.5Ta high-temperature shape memory alloy was investigated.X-ray diffraction measurem ent shows that the alloy is composed of orthorhombicα"-martensite.ωphase is not found in Ti-18.5Zr-10Nb-3.5Ta alloy due to the suppressing effect of Ta element.Theα"-martensite laths are found in the transmission electron microscope observation;after the bending deformation,there appear a lot of dislocations.The alloy exhibits a shape memory strain of 3.8%aud a high reverse martensite transformation start temperature of 464 K.The maximum two-way shape memory strain of 1.2%is obtained in the alloy with the prebending training strain of 10%.The mechanism can be ascribed to the effect of internal stress field caused by dislocations.

关键词： Ti-Zr Shape memory alloys Two-way shape memory effect

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Efflcient machining of a complex blisk channel using a disc cutter

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Chinese journal of Aeronautics 2024年第1期37卷 414-437页

作者： Xiangyu li Zhaoyu li Dong HE junxue REN Qian FENG Kai TANG Department of Mechanical and Aerospace Engineering Hong Kong University of Science and TechnologyHong Kong 999077China Key Laboratory of High Performance Manufacturing for Aero Engine(Northwestern Polytechnical University) Ministry of Industry and Information TechnologyXi’an 710072China Xi’an Sanhang Power Technology Co. LtdXi’an 710000China HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute FutianShenzhen 518057China HKUST Shenzhen Research Institute Shenzhen 518057China

For rough machining of a complex narrow cavity,e.g.,a complex blisk channel on an aero-engine,the typically used cutting tools are the slender cylindrical cutter and conical cutter.Nevertheless,as neither of the two is particularly suited for rough machining,wherein the main purpose is to remove a large volume as quickly as possible,the machining efficiency is low,especially when the part materials are of hard-to-cut types(e.g.,Titanium-alloy)for which it often takes days to rough machine a blisk.Fortunately,disc machining provides a new and efficient roughing solution,since a disc cutter with a large radius enables a much larger cutting speed and thus a larger material removal rate.However,due to the large radius of the disc cutter,its potential collision with narrow and twisted channels becomes a serious concern.In this paper,we propose a novel twophase approach for efficiently machining a complex narrow cavity workpiece using a disc-shaped cutter,i.e.,3+2-axis disc-slotting of the channel by multiple layers(rough machining)+five-axis disc-milling of the freeform channel side surfaces(semi-finish machining).Both simulation and physical cutting experiments are conducted to assess the effectiveness and advantages of the proposed method.The experimental results show that,with respect to a same cusp-height threshold on the channel side surfaces,the total machining time of the tested part by the proposed method is about only 36%of that by the conventional approach of plunging-milling(for roughing)plus milling by a slender cylindrical cutter(for semi-finishing).

关键词： Blisk channel CNC machining Disc cutter Roughing efficiency Tool path planning

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Surface-effect on detection ability of fluorescent Eu(btc)metal-organic frameworks to metal ions

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journal of Rare Earths 2021年第4期39卷 446-452页

作者： jiaolong Peng Wei Zhou Heping Ding Huanhuan Du Shujing j.li Beijing Advanced Innovation Center for Food Nutrition and Human Health Beijing Technology and Business UniversityBeijing 100048China Department of Chemistry College of Chemistry and Materials EngineeringBeijing Technology and Business UniversityBeijing 100048China

Eu(btc)metal organic frameworks(MOFs)were prepared by co-precipitation method via 1,2,4-benzenetricarboxylic acids(H3btc)connecting with Eu^(3+)ions,and the morphology was controlled from compact spherical to irregular honeycomb by adjusting the pH of reaction solutions.The luminescence properties of Eu(btc)MOFs are found to be related to the surface morphology of products,and the compact spherical one performs stronger emission intensity.The sensing ability of Eu(btc)MOFs to 11 kinds of metal ions was investigated and a prominent quenching effect occurrs in Fe^(3+),or Ni^(2+)solutions.Based on UV—vis absorption analysis,an“ion-fence”model presents the competition to absorb exciting light between Eu(btc)MOFs and adsorbed metal ions.Based on Stern-Volmer equation,the Eu(btc)detection is found with higher Ksv value and a lower detection limit.Meanwhile,a higher sensing efficiency is confirmed in the Eu(btc)MOFs with loose honeycomb due to aggravating porous surface offering much more sites for metal ions.

关键词： MOF Surface-effect Detection Metal ions Rare earths

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High-precision orbit prediction and error control techniques for COMPASS navigation satellite

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Chinese Science Bulletin 2014年第23期59卷 2841-2849页

作者： Xiaojie li jianhua Zhou Rui Guo Beijing Satellite Navigation Center

A new satellite orbit prediction method based on artificial neural network(ANN)model is proposed to improve the precision of orbit prediction.In order to avoid the difficulty of amending the dynamical model,it is attempted to use ANN model to learn the variation of orbit prediction error,and then the prediction result of ANN model is used to compensate the predicted orbit based on dynamic model to form a final predicted orbit.The experiment results showed that the orbit prediction error based on ANN model was less than that based on dynamical model,and the improvement effects for different satellites and different time were different.The maximum rates of improvement of predicting 8,15,30 d were respectively 80%,77.77%,85%.The orbit prediction error control technique based on the method of back overlap arc compare was brought forward to avoid the risk that the precision of predicted orbit is even worse after it is compensated by ANN model.The phenomena of failure were basically eliminated based on this technique,and the rate of failure was reduced from 30%to 5%.This technique could ensure that the engineering application of ANN model could come true.

关键词：北斗导航卫星差错控制技术轨道预报高精度人工神经网络模型动力学模型轨道预测神经网络学习

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Geochemistry and possible origin of the hydrocarbons from Wells Zhongshen1 and Zhongshen1C, Tazhong Uplift

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Science China Earth Sciences 2016年第1期59卷 840-850页

作者： SONG DaoFu WANG TieGuan li Meijun State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum

In 2013, a great breakthrough of deep petroleum exploration was achieved in the Cambrian pre-salt intervals of Wells Zhongshen1(ZS1) and Zhongshen1C(ZS1C), Tazhong Uplift. However, the hydrocarbon discovery in the Cambrian pre-salt intervals has triggered extensive controversy regarding the source of marine oils in the Tarim Basin. The geochemistry and origin of the Cambrian pre-salt hydrocarbons in Wells ZS1 and ZS1 C were investigated using GC, GC-MS and stable carbon isotope technique. These hydrocarbons can be easily distinguished into two genetic families based on their geochemical and carbon isotopic compositions. The oil and natural gases from the Awatage Formation of Well ZS1 are derived from Middle-Upper Ordovician source rocks. In contrast, the condensate and gases from the Xiaoerbulake Formation of Wells ZS1 and ZS1 C probably originate from Cambrian source rocks. The recent discovery of these hydrocarbons with two different sources in Wells ZS1 and ZS1 C suggests that both Middle-Upper Ordovician-sourced hydrocarbons and Cambrian-sourced petroleums are accumulated in the Tazhong Uplift, presenting a great exploration potential.

关键词：地球化学塔中隆起烃源岩碳氢化合物 GC-MS 中上奥陶统深层油气勘探碳同位素技术

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Management of high-flow arteriovenous malformation in the maxillofacial region

Management of high-flow arteriovenous malformation in the ma...

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中华口腔医学会全科口腔医学专业委员会第六次学术会议暨广...

作者： Huang D Deng W Chen S Zhang X li X li j Chen X The first affiliated hospital of Sun Yat-Sen university

Management of high-flow arteriovenous malformation(AVM) in the oral and maxillofacial region, one of the greatest challenges facing oral and maxillofacial surgeons, is patient-specific in almost all cases. The aim of this study was to review our experience with superselective intra-arterial embolization followed by surgical resection and bone wax packing(BWP) of the bone cavity and curettage to manage AVM. Sixteen patients with AVM of the oral and maxillofacial region were included in this study. All patients were evaluated with preoperative angiography, and superselective intra-arterial embolization of the lesions was done in the same session by the same interventional radiologists. Forty-eight to 72 hours later, surgical resection of the soft-tissue vascular lesions and BWP of the bone cavity and curettage were performed. There were no complications related to either the preoperative angiography or the embolization procedure. The pulsation and noise were absent, and the hemorrhage disappeared. Followed up after the surgical treatment for a mean of38 months(range, 7-63 months), 14 cases were controlled and 2 were improved, and no case was persistent or recurred. Superselective intra-arterial embolization followed by surgical resection and BWP of the bone cavity and curettage was an effective therapy in the oral and maxillofacial region.

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蜜蜂停止信号可以根据威胁的严重程度进行调节,并作为蜂群警报信号（英文）

蜜蜂停止信号可以根据威胁的严重程度进行调节,并作为蜂群警报信...

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作者： Tan K Dong S li X liu X Wang C li j Nieh jC

报警通讯是社会性生物抵御捕食者和群体防御一种主要的适应性机制。在亚洲,体型最大的大胡蜂--金环胡蜂（Vespa mandarinia）和体型较小的小胡蜂--凹吻胡蜂（Vespavelutina）是东方蜜蜂的天敌,常捕食东方蜜蜂的采集蜂及内勤蜂。同西方...

报警通讯是社会性生物抵御捕食者和群体防御一种主要的适应性机制。在亚洲,体型最大的大胡蜂--金环胡蜂（Vespa mandarinia）和体型较小的小胡蜂--凹吻胡蜂（Vespavelutina）是东方蜜蜂的天敌,常捕食东方蜜蜂的采集蜂及内勤蜂。同西方蜜蜂一样,当受到捕食者攻击时,东方蜜蜂也会释放出一种震动性的停止信号,使招募同伴外出采集的舞蹈行为停止。大胡蜂的攻击对东方蜜蜂的危害程度和致死率较高。受到大胡蜂攻击的东方蜜蜂比受到小胡蜂攻击的东方蜜蜂每次能释放出更多的停止信号。而且,受大胡蜂攻击时所释放的停止信号具有更高的震动频率,对东方蜜蜂舞蹈行为的抑制作用更明显。当在巢门口发动攻击时,由采集蜂和守卫蜂所释放的终止信号的持续时间显著的长于由采集蜂释放的终止信号。蜂巢内部的蜜蜂会根据胡蜂的危险程度,释放出相应的停止信号,警示同伴要留在安全的巣内而不是外出。此外,蜜蜂释放的报警信息素会触发守卫蜂对入侵的胡蜂群起而攻之,结成蜂球将胡蜂包围。蜜蜂通过复杂的"舞蹈语言"将食物的方位、距离等信息传递给同伴。报警信号与蜜蜂精巧的舞蹈语言相匹配,构成了舞蹈的触发-表达-报警-停止的完整过程。这是首次在脊椎动物以外发现如此精确的语音报警信号,报警信号既包含了危险的程度也包含了危险的类型。

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