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| 1 | Destruction of the North China Craton显示文摘A National Science Foundation of China(NSFC) major research project,Destruction of the North China Craton(NCC),has been carried out in the past few years by Chinese scientists through an in-depth and systematic observations,experiments and theoretical analyses,with an emphasis on the spatio-temporal distribution of the NCC destruction,the structure of deep earth and shallow geological records of the craton evolution,the mechanism and dynamics of the craton destruction.From this work the following conclusions can be drawn:(1) Significant spatial heterogeneity exists in the NCC lithospheric thickness and crustal structure,which constrains the scope of the NCC destruction.(2) The nature of the Paleozoic,Mesozoic and Cenozoic sub-continental lithospheric mantle(CLM) underneath the NCC is characterized in detail.In terms of water content,the late Mesozoic CLM was rich in water,but Cenozoic CLM was highly water deficient.(3) The correlation between magmatism and surface geological response confirms that the geological and tectonic evolution is governed by cratonic destruction processes.(4) Pacific subduction is the main dynamic factor that triggered the destruction of the NCC,which highlights the role of cratonic destruction in plate tectonics. | ZHU RiXiang XU YiGang ZHU Guang ZHANG HongFu XIA QunKe ZHENG TianYu | 2012 | Science China Earth Sciences2012，55，10： | 119 |
| 2 | On the timing and duration of the destruction of the North China Craton显示文摘The timing and duration of the destruction of the North China Craton, which is pivotal to understanding the destruction mechanism and its geodynamic controlling factors, still remain controversial. On the basis of the principles of magma genesis and evolution, first we outline magmatic expressions that can be related to cratonic destruction, then use magmatic and basin evolution trends to constrain the timescale of the lithospheric thinning in North China. The main conclusions include: (1) the thinning of the lithosphere beneath the North China Craton might have started, at least locally, since late Carboniferous-late Triassic, attained its climax during the late Jurassic-early Cretaceous, and continued till the end of late Cretaceous-early Cenozoic. The destruction of the North China Craton was a relatively slow, rather than a dramatic process. (2) The weakened lithospheric zones along the margins and interiors of the craton played an important role in cratonic destruction, partly accounting for the heterogeneous pattern of cratonic destruction. (3) The tectonic factors that controlled the destruction of the North China Craton may be multiple. The late Carboniferous southward subduction of the Paleo-Asian plate and the late Triassic collision between North China and South China may have re-activated the craton by influencing the thermal and integral structure of the craton. The Pacific subduction underneath the eastern Asian continent played a determinant role in the cratonic destruction, governing the distribution patterns of post-Mesozoic basins and major tectonic configuration, temporal change of magmatism and formation of the North-South gravity lineament. | XU YiGang LI HongYan PANG ChongJin HE Bin | 2009 | Chinese Science Bulletin2009，54，19： | 70 |
| 3 | Opening and evolution of the South China Sea constrained by studies on volcanic rocks:Preliminary results and a research design显示文摘The South China Sea (SCS) is characterized by abundant seamounts, which provide important information about the evolution of the SCS and related deep processes. Cenozoic volcanism in the SCS and its surroundings comprises three stages relative to the spreading of the SCS:prespreading (>32 Ma), syn-spreading (32-16 Ma), and post-spreading (<16 Ma). The pre-spreading magmatism predominantly occurs on the northern margin of the SCS and in South China coastal areas and shows a bi-modal affinity. The syn-spreading magmatic activity was very limited on the periphery of the SCS, but may be concentrated in the SCS. However, seafloor samples of this stage are not available yet because of overlying thick sedimentary deposits. Post-spreading magmatism is widespread in the central and southwest sub-basins of the SCS, Hainan Island, Leizhou Peninsula, Thailand, and Vietnam. These are mainly alkali basalts with subordinate tholeiites, and display OIB-type geochemical characteristics. The Dupal isotope anomaly and presence of high-magnesian olivine phenocrysts suggests their possible derivation from the Hainan mantle plume. The temporal and spatial distribution of Cenozoic volcanism in the SCS and its surroundings may be accounted for either by plate stress re-organization before and after SCS spreading, or by ridge suction of plume flow during opening of the SCS. If the latter is the case, the volcanic rocks within the SCS basin may not be typical mid-ocean ridge basalts (MORB). It remains puz-zling, however, that the transition between the South China continental margin and the SCS basin does not have features typical of a volcanic rifted margin. Clearly, the relationship between mantle plume and SCS opening needs further evaluation. A better un-derstanding of the link between deep processes and opening of the SCS not only requires enhanced studies on igneous petrogene-sis, but also is heavily dependent on systematic sampling of seafloor rocks. | XU YiGang WEI JingXian QIU HuaNing ZHANG HuiHuang HUANG XiaoLong | 2012 | Chinese Science Bulletin2012，57，24： | 43 |
| 4 | Crustal velocity structure in the Emeishan large igneous province and evidence of the Permian mantle plume activity显示文摘The Emeishan large igneous province(ELIP) in SW China is interpreted to be associated with an ancient mantle plume. Most of the constraints on the role of mantle plume in the generation of the Emeishan flood basalts were provided by geological and geochemical methods, but the geophysical investigation is very limited. In order to better understand the deep structure and features of ELIP, we have studied the crustal velocity structure using the data acquired from the Lijiang-Panzhihua-Qingzhen wide-angle seismic profile. This profile crosses the three sub-zones of the ELIP(the inner, intermediate, and outer zones), divided based on the differential erosion and uplift of the Maokou limestone. The results provided by the active source seismic experiment demonstrate:(1) The average depth of the crystalline basement along the profile is about 2 km.(2) The middle crust in the Inner Zone is characterized by high-velocity anomalies, with the average velocity of 6.2-6.6 km/s, which is about 0.1– 0.2 km/s higher than the normal one. The velocity of the lower crust in the inner zone is 6.9-7.2 km/s, higher than those observed in the intermediate and outer zones(6.7-7.0 km/s). Relatively low velocity anomalies appear in the upper, middle and lower crusts near the junction of the inner zone and intermediate zone, probably due to the effect of the Xiaojiang fault(XJF).(3) The average velocity of the crust is comparatively low on both sides of XJF, especially on the east side, and the average velocity of the consolidated continental crust is also low there. This may suggest that the XJF extends at least down to 40 km deep, even beyond through the crust.(4) The depth to the Moho discontinuity decrease gradually from 47-53 km in the inner zone, via 42-50 km in the intermediate zone to 38-42 km in the outer zone. In the inner zone, the Moho uplifts locally and the(consolidated) crust is characterized by high-velocity anomalies, which are likely related to intensive magma intrusion and underplating associated with melting of plume head. Overall the crustal velocity structure in the study area recorded the imprint left by the Permian Emeishan mantle plume. | XU Tao ZHANG ZhongJie LIU BaoFeng CHEN Yun ZHANG MingHui TIAN XiaoBo XU YiGang TENG JiWen | 2015 | Science China Earth Sciences2015，58，7： | 36 |
| 5 | The subduction of the west Pacific plate and the destruction of the North China Craton显示文摘While a general concensus has recently been reached as to the causal relationship between the subduction of the west Pacific plate and the destruction of the North China Craton, a number of important questions remain to answer, including the initial subduction of west Pacific plate beneath the eastern Asian continent, the position of west Pacific subduction zone during the peak period of decratonization(i.e., Early Cretaceous), the formation age of the big mantle wedge under eastern Asia, and the fate of the subducted Pacific slab. Integration of available data suggests that the subduction of the western Pacific plate was initiated as early as Early Jurrasic and the subduction zone was situated to 2,200 km west of the present-day trench in the Early Creataceous, as a result of eastward migration of the Asian continent over a distance of ca. 900 km since the Early Cretaceous.The retreat of the subducting west Pacific plate started ~145 Ma ago, corresponding to the initial formation of the big mantle wedge system in the Early Cretaceous. The subduction of the Pacific slab excerted severe influence on the North China Craton most likely through material and energy echange between the big mantle wedge and overlying cratonic lithosphere. The evolution history of the west Pacific plate was reconstructed based on tectonic events. This allows to propose that the causes of phases A and B for the Yanshanian orogeny were respectively related to rapid low-angle subduction and to lowering subduction angle of the west Pacific plate. At ca. 130–120 Ma, the subduction of the west Pacific plate was characterized by increasing subducting angle, slab rollback and rapid trench retreat, leading to the final stagnation of the subducting slab within the mantle transition zone. This process may have significantly affected the physical property and viscosity of the mantle wedge above the stagnant slab, resulting in non-steady mantle flows. The ingression of slab-released melts/fluids would significantly lower the viscosity of the mantle wedge and overlying lithosphere, inducing decratonization. This study yields important bearings on the relationship between the subduction of the west Pacific plate and the evolution of the lithospheric mantle beneath the North China Craton. | Rixiang ZHU Yigang XU | 2019 | Science China Earth Sciences2019，62，9： | 38 |
| 6 | Thinning and destruction of the cratonic lithosphere:A global perspective显示文摘It has been proposed that the North China Craton(NCC)was thinned up to a thickness of>100 km during the Phanerozoic,and underwent an associated craton destruction.Evidently,it is an important topic worthy of future study to understanding the mechanism of cratonic destruction and its role played in the continental evolution.After synthesized the global cratons of India,Brazil,South Africa,Siberia,East Europe(Baltic)and North America,we found that lithospheric thinning is common in the cratonic evolution,but it is not always associated with craton destruction.Most cratons was thinned by thermal erosion of mantle plume or mantle upwelling,which,however,may not cause craton destruction.Based on the studies of the North American and North China Cratons,we suggest that oceanic subduction plays an important role in caton destruction.Fluids or melts released by dehydration of the subducted slabs metasomatize the mantle wedge above and trigger extensive partial melting.More importantly,the metasomatized mantle lost its original rigidity and make craton easier to be deformed and then to be destoyed.Therefore,we suggest that the widespread crust-derived granite and large-scale ductile deformation within the continental crust can be regarded as the petrological and structural indicators of craton destruction,respectively. | WU FuYuan XU YiGang ZHU RiXiang ZHANG GuoWei | 2014 | Science China Earth Sciences2014，57，12： | 33 |
| 7 | Preparation and coagulation efficiency of polyaluminium ferric silicate chloride composite coagulant from wastewater of high-purity graphite production显示文摘The aim of the present work was to produce a polyaluminium ferric silicate chloride (PAFSiC) coagulant from acidic and alkaline wastewater of purifying graphite by roasting, and subsequently to evaluate coagulation efficiency of the reagent by treating surface water from the Yellow River as well as municipal wastewater in comparison with the conventional coagulant polyaluminium chloride (PAC). The PAFSiC coagulant was prepared by co-polymerization. The effects of (Al+Fe)/Si molar ratio, OH/(Al+Fe) molar ratio (i.e., γ value), coagulant dosage and pH value of test suspension on the coagulation behavior of FAFSiC and the stability of the PAFSiC were also examined. Results showed that PAFSiC performed more efficiently than PAC in removing turbidity, chemical oxygen demand (COD), and total phosphate (TP). The PAFSiC with a γ value of 2.0 and (Al+Fe)/Si ratio of 5 (PAFSiC 2.0/5) showed excellent coagulation effect for both turbidity and COD, while PAFSiC 1.0/5 was the best for TP. The optimum coagulation pH range of PAFSiC 2.0/5 was 5.0–9.0, slightly wider than that of PAC (6.0–8.0). The process can be easily incorporated into high-purity graphite production plants, thereby reducing wastewater pollution and producing a valuable coagulant. | Xiaoxia Niu Xili Li Jihong Zhao Yigang Ren Yanqin Yang | 2011 | Journal of Environmental Sciences2011，23，7： | 23 |
| 8 | Domains and enrichment mechanism of the lithospheric mantle in western Yunnan: A comparative study on two types of Cenozoic ultrapotassic rocks显示文摘Geochemical comparison of two suites of Cenozoic potassic volcanic rocks in western Yunnan reveals the existence of two mantle domains beneath this region, which corre- spond to their respective tectonic affinity. The Erhai ultrapotassic rocks (42—24Ma) in western Yangtze Craton are characterized by LILE enrichment, HFSE depletion, low TiO2 content (<1%), high initial Sr/86Sr (0.7064—0.7094) and negative εNd (?3.84—?4.64). Geochemically similar to 87 K-rich volcanism in subduction setting, they were probably originated from a refractory spinel harzburgitic source metasomatized by subduction-related fluids. In contrast, the Maguan potas- sic magmas (<16Ma) in the South China Block show an OIB-type trace elemental signature, high TiO2 content (>2%), low initial 87 Sr/86Sr (0.7041—0.7060) and positive εNd (5.46—7.03). These features resemble the typical intraplate potassic rocks around the world. These rocks are thus interpreted as melting products of a fertile garnet lherzolitic source which has been infiltrated by small-volume, asthenosphere-derived silicate melts. The temporal and spatial distribution of these two types of K-rich rocks cannot be explained by any unified tectonic model. It is proposed that the Oligocene magmatism in the Erhai area may have resulted from convective thinning of the thickened lithosphere, whereas the post-Miocene volcanism in the Maguan area was related to the opening of South China Sea. | XIA Ping XU Yigang | 2005 | Science China Earth Sciences2005，48，3： | 19 |
| 9 | LITHOSPHERE-ASTHENOSPHERE INTERACTION: A COMPARATIVE STUDY ON CENOZOIC AND MESOZOIC BASALTS AROUND BOHAI AREA | Yigang Xu Weiming Fan and Ge Lin( Guangzhou Institute of Geochemistry , Chinese Academy of Sciences , Guangzhou , P. R, China)(Department of Gedegy, Royal Holoway Univoersity of London, Egham, Surrey, TW20OEX , UK)(Changsha Institute of Geotectonics,Chin | 1995 | Geotectonica et Metallogenia1995，19，4： | 16 |
| 10 | Ways to sparse representation:An overview显示文摘Many algorithms have been proposed to find sparse representations over redundant dictionaries or transforms. This paper gives an overview of these algorithms by classifying them into three categories:greedy pursuit algorithms,lp norm regularization based algorithms,and iterative shrinkage algorithms. We summarize their pros and cons as well as their connections. Based on recent evidence,we conclude that the algorithms of the three categories share the same root:lp norm regularized inverse problem. Finally,several topics that deserve further investigation are also discussed. | YANG JingYu PENG YiGang XU WenLi DAI QiongHai | 2009 | Science in China(Series F)2009，52，4： | 15 |
| 11 | Generation of Cenozoic intraplate basalts in the big mantle wedge under eastern Asia显示文摘The roles of subduction of the Pacific plate and the big mantle wedge(BMW) in the evolution of east Asian continental margin have attracted lots of attention in past years. This paper reviews recent progresses regarding the composition and chemical heterogeneity of the BMW beneath eastern Asia and geochemistry of Cenozoic basalts in the region, with attempts to put forward a general model accounting for the generation of intraplate magma in a BMW system. Some key points of this review are summarized in the following.(1) Cenozoic basalts from eastern China are interpreted as a mixture of high-Si melts and low-Si melts. Wherever they are from, northeast, north or south China, Cenozoic basalts share a common low-Si basalt endmember, which is characterized by high alkali, Fe_2O_3~T and TiO_2 contents, HIMU-like trace element composition and relatively low ^(206)Pb/^(204)Pb compared to classic HIMU basalts. Their Nd-Hf isotopic compositions resemble that of Pacific Mantle domain and their source is composed of carbonated eclogites and peridotites. The high-Si basalt endmember is characterized by low alkali, Fe_2O_3~T and TiO_2 contents, Indian Mantle-type Pb-Nd-Hf isotopic compositions, and a predominant garnet pyroxenitic source. High-Si basalts show isotopic provinciality, with those from North China and South China displaying EM1-type and EM2-type components, respectively, while basalts from Northeast China containing both EM1-and EM2-type components.(2) The source of Cenozoic basalts from eastern China contains abundant recycled materials, including oceanic crust and lithospheric mantle components as well as carbonate sediments and water. According to their spatial distribution and deep seismic tomography, it is inferred that the recycled components are mostly from stagnant slabs in the mantle transition zone,whereas EM1 and EM2 components are from the shallow mantle.(3) Comparison of solidi of garnet pyroxenite, carbonated eclogite and peridotite with regional geotherm constrains the initial melting depth of high-Si and low-Si basalts at <100 km and^300 km, respectively. It is suggested that the BMW under eastern Asia is vertically heterogeneous, with the upper part containing EM1 and EM2 components and isotopically resembling the Indian mantle domain, whereas the lower part containing components derived from the Pacific mantle domain. Contents of H_2O and CO_2 decrease gradually from bottom to top of the BMW.(4) Melting of the BMW to generate Cenozoic intraplate basalts is triggered by decarbonization and dehydration of the slabs stagnated in the mantle transition zone. | Yigang XU Hongyan LI Lubing HONG Liang MA Qiang MA Mingdao SUN | 2018 | Science China Earth Sciences2018，61，7： | 13 |
| 12 | Mantle upwelling beneath the South China Sea and links to surrounding subduction systems显示文摘The evolution of the South China Sea(SCS)is directly linked to the complex subduction systems of the surrounding Pacific,Philippine Sea and Indo-Australian Plates(Fig.1a).Major advances in the last several years are providing new insights into the SCSmantle dynamics,through regional seismic imaging of the upper mantle[1,2],unprecedented IODP drilling expeditions(349/367/368/368X)[3-5]that obtained the oceanic basement basalt samples for the first time,geochemical analyses of the SCS-mantle source compositions[6-8]and geodynamic modeling[9,10]. | Jian Lin Yigang Xu Zhen Sun Zhiyuan Zhou | 2019 | National Science Review2019，6，5： | 13 |
| 13 | Geochronologic and petrochemical evidence for the genetic link between the Maomaogou nepheline syenites and the Emeishan large igneous province显示文摘The Maomaogou nepheline syenite is located at the inner zone of the Emeishan large igneous province and exhibits intrusive contact with the Emeishan basalts. SHRIMP U-Pb dating on zircons from this syenite yields an age of 261.6±4.4 Ma, in agreement with the age of the Panzhihua layered intrusion and the eruption age of the Emeishan basalts as constrained by stratigraphic data. Geochemical data fur-ther suggest that the Maomaogou syenite has a source analogue to the Emeishan basalt, and may have been formed by partial melting of gabbroic cumulates underplated in the lower crust. As s result, tem-poral and spatial relationships and petrogenetic constraints provide evidence for the genetic link be-tween basalts, mafic/ultramafic and intermediate/acidic intrusives in the Panxi area. | LUO ZhenYu XU YiGang HE Bin SHI YuRuo HUANG XiaoLong | 2007 | Chinese Science Bulletin2007，52，7： | 12 |
| 14 | Activation of northern margin of the North China Craton in Late Paleozoic:Evidence from U-Pb dating and Hf isotopes of detrital zircons from the Upper Carboniferous Taiyuan Formation in the Ningwu-Jingle basin显示文摘LA-MC-ICPMS U-Pb dating has been performed on detrital zircons from the Upper Carboniferous Tai-yuan Formation (N-8) in the Ningwu-Jingle Basin, west of the North China Craton (NCC). The ages of 72 detrital zircon grains are divided into three groups: 303―320 Ma (6 grains), 1631―2194 Ma (37 grains, peaked at 1850 Ma), 2318―2646 Ma (29 grains, peaked at 2500 Ma). Detrital zircons of Group 2 and Group 3 were likely derived from the basement of the NCC. Group 1 zircons exhibit 176Hf/177Hf ratios ranging from 0.281725 to 0.282239, with corresponding negative εHf(t) values of -12.4―-30.3 and old Hf model ages of 1.4―2.2 Ga. These characteristics show a strong resemblance to those of Carboniferous igneous zircons from the Inner Mongolia Paleo-uplift (IMPU) on the northern margin of the NCC, but differ significantly from those of the Xing-Meng Orogenic Belt, suggesting that the source of the Tai-yuan Formation partly came from the IMPU. All detrital zircons of Group 1 have relatively high Th/U ratios (> 0.67), indicating a magmatic origin. The mean age (304 ± 6 Ma) of the two youngest grains is close to the depositional age of the Taiyuan Formation, suggesting a strong tectonic uplift and magmatism in the IMPU during the Late Carboniferous. This paper provides important geological evidence for the activation of the northern margin of the NCC in the Late Paleozoic. | LI HongYan XU YiGang HUANG XiaoLong HE Bin LUO ZhenYu YAN Bin | 2009 | Chinese Science Bulletin2009，54，4： | 12 |
| 15 | A linear ridgelet network approach for fault diagnosis of analog circuit显示文摘A linear ridgelet network combining ridgelet, linear term and the standard feed-forward neural network used for diagnosing the faults of analog circuit is constructed, and a training algorithm based on the steepest gradient descent method and momentum method for this network and the procedure for diagnosing these faults are proposed. The resulting linear ridgelet network can learn more rapidly from training samples and handle more effectively the complicated fault information of circuit under test than wavelet network and ridgelet network, classifying these faults effeciently and correctly and achieving a high classification accuracy. The simulation results demonstrate the effectiveness of this approach. | XIAO YingQun& HE YiGang College of Electrical and Information Engineering, Hunan University, Changsha 410082, China | 2010 | Science China(Information Sciences)2010，53，11： | 10 |
| 16 | Distribution and deposition of polycyclic aromatic hydrocarbons in precipitation in Guangzhou, South China显示文摘Polycyclic aromatic hydrocarbons (PAHs) were measured in precipitation from March to August 2005 in Guangzhou, South China. Fourteen PAHs were studied, and their total concentrations varied from 616.6 to 3486.7 ng/L in dissolved phase and from 403.8 to 3125.5 ng/L in particulate phase. The estimated deposition loading of PAHs was 3568 μg/m2 during the monitoring period. The deposition of PAHs was a potential source for Pearl River comparing with the contents of surface water. In addition, the high concentration in precipitation here implied that PAHs pollution was a potential environmental problem in Guangzhou. Most precipitation concentrations of PAHs in March (the last month in winter in Guangzhou) were higher than in the other months (in rainy season). PAHs inclined to be adsorbed to particulate phase with the increase of molecular weight in rainwater. Combustion of fossil fuel and biomass might be the major source of PAHs, while the direct leakage or volatilization from petroleum products might be insignificant. | HUANG Deyin PENG Ping'an XU Yigang DENG Yunyun DENG Hongmei | 2009 | Journal of Environmental Sciences2009，21，5： | 9 |
| 17 | Precise measurement of stable (δ^(88/86)Sr) and radiogenic (^(87)Sr/^(86)Sr) strontium isotope ratios in geological standard reference materials using MC-ICP-MS显示文摘A new method for high-precision measurements of stable (δ88/86Sr) and radiogenic (87Sr/86Sr) Sr isotope ratios was developed on the MC-ICP-MS using a standard-sample-standard bracketing protocol. By carefully monitoring and controlling the accumulation of the on-peak backgrounds (i.e. the carryover memory) on the instrument, our method can provide an external precision of around 0.010‰ to 0.014‰ for 88/86 Sr measurements. Such precision is comparable to that achieved by double-spike TIMS method (DS-TIMS), and 2-3 times better than those of the previously reported results by MC-ICP-MS without spiking. The results of the standard seawater IAPSO are also identical to those by DS-TIMS. However, our method is more advantageous, efficient and convenient to use for routine Sr isotopic analysis than the DS-TIMS method as there is no need to prepare and calibrate the 84Sr-87 Sr double spike. Using this method, we measured the δ88/86Sr values in a series of international geological rock standards, which show large variability, with the lowest value (0.20‰) registered in JG-2, a terrestrial granite, and the highest value (0.539‰) in UB-N, a serpentinite. This may provide an additional means for isotopic characterization of geological processes, adding a new dimension over the traditional use of radiogenic Sr isotopic ratio 87Sr/86Sr. | MA JinLong WEI GangJian LIU Ying REN ZhongYuan XU YiGang YANG YongHong | 2013 | Chinese Science Bulletin2013，58，25： | 9 |
| 18 | A NEURAL-BASED NONLINEAR L_1-NORM OPTIMIZATION ALGORITHM FOR DIAGNOSIS OF NETWORKS*显示文摘Based on exact penalty function, a new neural network for solving the L1-norm optimization problem is proposed. In comparison with Kennedy and Chua’s network(1988), it has better properties.Based on Bandler’s fault location method(1982), a new nonlinearly constrained L1-norm problem is developed. It can be solved with less computing time through only one optimization processing. The proposed neural network can be used to solve the analog diagnosis L1 problem. The validity of the proposed neural networks and the fault location L1 method are illustrated by extensive computer simulations. | He Yigang (Department of Electrical Engineering, Hunan University, Changsha 410082)Luo Xianjue Qiu Guanyuan(School of Electrical Engineering, Xi’an Jiaotong University, Xi’an 710049) | 1998 | Journal of Electronics(China)1998，15，4： | 8 |
| 19 | Study of action mechanisms and properties of Cr^(3+) cross-linked polymer solution with high salinity显示文摘Performance characteristics of partially hydrolyzed polyacrylamide (HPAM) and cross-linked polymer (CLP, Cr 3+ as the cross linker) solutions have been investigated. A Brookfield viscometer, rheometer, dynamic light scattering system, and core flow device have been used to measure the viscosity, viscoelasticity, polymer coil dimensions, molecular configuration, flow characteristics, and profile modification. The results show that, under conditions of high salinity and low HPAM and Cr 3+ concentrations, cross-linking mainly occurred between different chains of the same HPAM molecule in the presence of Cr 3+ , and a cross-linked polymer (CLP) system with a local network structure was formed. Compared with an HPAM solution of the same concentration, the apparent viscosity of the CLP solution increased slightly or remained almost unchanged, but its viscoelasticity (namely storage modulus, loss modulus, and first normal stress difference) increased, and the resistance coefficient and residual resistance coefficient increased significantly. This indicates that the CLP solution exhibits a strong capability to divert the sequentially injected polymer flood from high-permeability zones to low-permeability zones in a reservoir. Under the same HPAM concentration conditions, the dimensions of polymer coils in the CLP solution increased slightly compared with the dimensions of polymer coils in HPAM solution, which were smaller than the rock pores, indicating that the cross-linked polymer solution was well adapted to reservoir rocks. Core flood experiments show that at the same cost of reagent, the oil recovery by CLP injection (HPAM-1, Cr 3+ as the cross linker) is 3.1% to 5.2% higher than that by HPAM- 2 injection. | Lu Xiangguo Liu Jinxiang Wang Rongjian Liu Yigang Zhang Song | 2012 | Petroleum Science2012，9，1： | 8 |
| 20 | Classification of the Gut Microbiota of Patients in Intensive Care Units During Development of Sepsis and Septic Shock显示文摘The gut microbiota of intensive care unit(ICU)patients displays extreme dysbiosis associated with increased susceptibility to organ failure,sepsis,and septic shock.However,such dysbiosis is difficult to characterize owing to the high dimensional complexity of the gut microbiota.We tested whether the concept of enterotype can be applied to the gut microbiota of ICU patients to describe the dysbiosis.We collected 131 fecal samples from 64 ICU patients diagnosed with sepsis or septic shock and performed 16S rRNA gene sequencing to dissect their gut microbiota compositions.During the development of sepsis or septic shock and during various medical treatments,the ICU patients always exhibited two dysbiotic microbiota patterns,or ICU-enterotypes,which could not be explained by host properties such as age,sex,and body mass index,or external stressors such as infection site and antibiotic use.ICU-enterotype I(ICU E1)comprised predominantly Bacteroides and an unclassified genus of Enterobacteriaceae,while ICU-enterotype II(ICU E2)comprised predominantly Enterococcus.Among more critically ill patients with Acute Physiology and Chronic Health Evaluation II(APACHE II)scores>18,septic shock was more likely to occur with ICU E1(P=0.041).Additionally,ICU E1 was correlated with high serum lactate levels(P=0.007).Therefore,different patterns of dysbiosis were correlated with different clinical outcomes,suggesting that ICU-enterotypes should be diagnosed as independent clinical indices.Thus,the microbial-based human index classifier we propose is precise and effective for timely monitoring of ICU-enterotypes of individual patients.This work is a first step toward precision medicine for septic patients based on their gut microbiota profiles. | Wanglin Liu Mingyue Cheng Jinman Li Peng Zhang Hang Fan Qinghe Hu Maozhen Han Longxiang Su Huaiwu He Yigang Tong Kang Ning Yun Long | 2020 | Genomics, Proteomics & Bioinformatics2020，18，6： | 7 |
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