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Experimental Study on Phase Characteristics of CO2 Injection in BZ13-2 Strong Volatile Oil Reservoir in Bohai Sea Buried Hills
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作者 Zhennan Gao Lei Zhang +2 位作者 yong jiang Jingtao Wu Chenxu Yang 《Open Journal of Geology》 2023年第7期763-772,共10页
BZ13-2 oil field is a deep submerged strongly volatile reservoir in Bohai Sea. This oil reservoir has the characteristics of high gas oil ratio and small difference in formation pressure and saturation point pressure.... BZ13-2 oil field is a deep submerged strongly volatile reservoir in Bohai Sea. This oil reservoir has the characteristics of high gas oil ratio and small difference in formation pressure and saturation point pressure. It usually adopts gas injection development to avoid crude oil degassing and fast decreasing production capacity. However, the phase characteristics and miscibility mechanism of this high-temperature and high-pressure fluid after gas injection are not clear. Therefore, it is necessary to study the feasibility of CO<sub>2</sub> injection to improve oil recovery in near critical volatile oil reservoirs through CO<sub>2</sub> injection experiments. In the early stage of the depletion experiment, the content of heavy components in the remaining oil increased significantly, so the depletion method is not conducive to the development of such reservoirs. With the increase of CO<sub>2</sub> injection, the volumetric expansion coefficient of formation crude oil increases significantly, while the saturation pressure and formation crude oil viscosity remain basically unchanged. The minimum miscible pressure experiment shows that CO<sub>2</sub> injection under formation pressure conditions can achieve multiphase miscibility. Based on experimental research results, the BZ13-2 oilfield is suitable for early gas injection development and can significantly improve recovery. 展开更多
关键词 Bohai Buried Hills Strongly Volatile Reservoir Gas Injection and Development Phase Characteristics Fine Tube Experiment
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依赖环境的氢化钛相稳定性:第一性原理预测
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作者 沈春雷 刘艺 +5 位作者 宫裕祥 刘正卿 江勇 许灿辉 周晓松 龙兴贵 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2023年第10期3017-3026,共10页
在充分考虑所有可能的H原子构型的条件下,构建各种TiH_(x)(x=1-2)相结构,并基于第一性原理能量学,计算评估各相的形成能力及其力学和热力学稳定性,进而构建稳定和亚稳TiH_(x)的相稳定性图。结果显示,很多稳定和亚稳TiH_(x)相具有非常接... 在充分考虑所有可能的H原子构型的条件下,构建各种TiH_(x)(x=1-2)相结构,并基于第一性原理能量学,计算评估各相的形成能力及其力学和热力学稳定性,进而构建稳定和亚稳TiH_(x)的相稳定性图。结果显示,很多稳定和亚稳TiH_(x)相具有非常接近的形成能,可能同时共存。这些相的相对稳定性强烈依赖于环境温度(T)和氢分压(p(H_(2)))。在整个感兴趣的T和p(H_(2))范围内,只可能存在γ-TiH和γ-TiH_(2)2种稳定相,以及ε-TiH、γ-TiH_(1.5)、ε-TiH_(1.75)、δ-TiH_(1.75)和ε-TiH_(2)5种亚稳相。这些亚稳相均满足力学稳定性,且在热力学上具有不断吸收或释放H,向平衡相γ-TiH_(2)或γ-TiH发生转化的趋势。 展开更多
关键词 氢化钛 相稳定性 亚稳相 第一性原理
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高分子分散剂对分散聚合制备聚甲基丙烯酸甲酯微球分散效果的影响
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作者 孙春雨 苏海棠 +2 位作者 韩雪莲 姜勇 王志飞 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2023年第7期1-7,共7页
以甲基丙烯酸甲酯为聚合单体、偶氮二异丁腈为引发剂,通过分散聚合方法在甲醇/水介质中制备了1~2μm的聚甲基丙烯酸甲酯(PMMA)微球,研究了4种高分子分散剂对微球粒径和均匀性的影响并探讨了其影响机制。通过傅里叶变换红外光谱仪和扫描... 以甲基丙烯酸甲酯为聚合单体、偶氮二异丁腈为引发剂,通过分散聚合方法在甲醇/水介质中制备了1~2μm的聚甲基丙烯酸甲酯(PMMA)微球,研究了4种高分子分散剂对微球粒径和均匀性的影响并探讨了其影响机制。通过傅里叶变换红外光谱仪和扫描电子显微镜对微球的化学组成和形貌进行了表征,结果表明,不同分散剂对微球尺寸及其分布有着显著影响,以聚乙烯醇(PVA)作分散剂时体系容易失稳,产生颗粒沉降,有小颗粒产生,微球平均粒径(Dn)为1.2μm、多分散系数(PDI)为0.045;以聚乙烯吡咯烷酮(PVP)作分散剂微球均一性较差,体系也会产生颗粒聚并沉降,Dn为1.45μm、PDI为0.105;以聚丙烯酸(PAA)作分散剂,得到均一性更差的微球,Dn为1.85μm、PDI为0.3;以聚乙二醇(PEG)为分散剂则能得到均匀的微球,Dn为1.15μm、PDI为0.041,微球粒径和多分散系数随着PEG相对分子质量的增大呈先减小后增大的趋势;粒径随PEG浓度增加呈先增大后减小趋势,在添加量超过20%后,粒径随浓度增加而减小,PDI随PEG浓度的变化趋势与粒径基本一致。 展开更多
关键词 聚甲基丙烯酸甲酯微球 分散聚合 分散剂 单分散
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流动电极微生物电合成提高产物生成速率及降低能量消耗
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作者 褚娜 王东麟 +5 位作者 王厚锋 梁勤军 常佳丽 高瑜 蒋永 曾建雄 《Engineering》 SCIE EI CAS CSCD 2023年第6期157-167,M0007,共12页
微生物电合成(microbial electrosynthesis,MES)利用可再生电力驱动微生物固定CO_(2)合成化学品,在推进碳循环经济中具有一定潜力,受到广泛关注。但是,很少有研究通过高效反应器设计来促进产乙酸并降低能耗。本研究中,新型流动电极MES... 微生物电合成(microbial electrosynthesis,MES)利用可再生电力驱动微生物固定CO_(2)合成化学品,在推进碳循环经济中具有一定潜力,受到广泛关注。但是,很少有研究通过高效反应器设计来促进产乙酸并降低能耗。本研究中,新型流动电极MES反应器的总产乙酸速率[(16±1)g·m^(-2)·d^(-1)]比无粉末活性炭(powder activated carbon,PAC)对照[(8±3)g·m^(-2)·d^(-1)]高两倍。流动电极MES反应器的库伦效率为43.5%±3.1%,能量消耗为(0.020±0.005)k Wh·g^(-1),产乙酸的能量效率为18.7%±1.3%。基于PAC的流动电极能够降低水跨膜通量、传质阻力,但是对装置电压、流变行为、乙酸吸附的影响较小。流动电极MES反应器中,能量代谢相关基因高表达,Acetobacterium的丰度增加。MES反应器中同时存在用于碳固定的还原性乙酰辅酶A途径(Wood–Ljungdahl pathway,WLP)与还原性三羧酸循环途径(reductive citric acid cycle,r TCA)。堆叠型流动电极MES中的乙酸浓度达7.0 g·L^(-1)。本研究提供一种构建可扩展MES反应器的新方法,促进CO_(2)利用以及产物生成。 展开更多
关键词 微生物电合成 乙酸浓度 能量消耗 三羧酸循环 传质阻力 生成速率 能量效率 粉末活性炭
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Comprehensive evaluation of chemical breakers for multistage network ultra-high strength gel
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作者 Zheng Kang Hu Jia +4 位作者 Zhong-Guo Li Biao Xia Yi Wang yong jiang Han-Lin Peng 《Petroleum Science》 SCIE EI CSCD 2023年第5期2864-2878,共15页
Polymer gels have been accepted as a useful tool to address many sealing operations such as drilling and completion,well stimulation,wellbore integrity,water and gas shutoff,etc.Previously,we developed an ultra-high s... Polymer gels have been accepted as a useful tool to address many sealing operations such as drilling and completion,well stimulation,wellbore integrity,water and gas shutoff,etc.Previously,we developed an ultra-high strength gel(USGel)for medium to ultra-low temperature reservoirs.However,the removal of USGel is a difficult problem for most temporary plugging operations.This paper first provides new insights into the mechanism of USGel,where multistage network structure and physical entanglement are the main reasons for USGel possessing ultra-high strength.Then the effects of acid breakers,encapsulated breakers,and oxidation breakers(including H_(2)O_(2),Na_(2)S_(2)O_(8),Ca(ClO)_(2),H_(2)O_(2)+NaOH,Na_(2)S_(2)O_(8)+NaOH,and Ca(ClO)_(2)+NaOH)were evaluated.The effects of component concentration and temperature on the breaking solution were studied,and the corrosion performance,physical simulation and formation damage tests of the breaking solution were carried out.The final formulation of 2%-4%NaOH+4.5%-6%H_(2)O_(2) breaking solution was determined,which can make USGel completely turn into water at 35e105C.The combinations of“acid t breaking solution”,“acid+encapsulated breaker”and“encapsulated breaker+breaking solution”were evaluated for breaking effect.The acid gradually reduced the volume of USGel,which increased the contact area between breaking solution and USGel,and the effect of“4%acid+breaking solution”was 23 times higher than that of breaking solution alone at 35C.However,the acid significantly reduced the strength of USGel.This paper provides new insights into the breaking of high-strength gels with complex network structures. 展开更多
关键词 Gel breaking Polymer gel Ultra-high strength Chemical breakers Multistage network
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Metal-organic decomposition growth of thin film metastable perovskite nickelates with kinetically improved quantum transitions
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作者 Haiyan Li Yuzhao Wang +7 位作者 Fanqi Meng Wei Mao Xingzhong Cao Yi Bian Hao Zhang yong jiang Nuofu Chen Jikun Chen 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第12期2441-2450,共10页
The multiple quantum transitions within d-band correlation oxides such as rare-earth nickelates(RENiO_(3))triggered by critical temperatures and/or hydrogenation opened up a new paradigm for correlated electronics app... The multiple quantum transitions within d-band correlation oxides such as rare-earth nickelates(RENiO_(3))triggered by critical temperatures and/or hydrogenation opened up a new paradigm for correlated electronics applications,e.g.ocean electric field sensor,bio-sensor,and neuron synapse logical devices.Nevertheless,these applications are obstructed by the present ineffectiveness in the thin film growth of the metastable RENiO_(3)with flexibly adjustable rare-earth compositions and electronic structures.Herein,we demonstrate a metal-organic decompositions(MOD)approach that can effectively grow metastable RENiO_(3)covering a large variety of the rare-earth composition without introducing any vacuum process.Unlike the previous chemical growths for RENiO_(3)relying on strict interfacial coherency that limit the film thickness,the MOD growth using reactive isooctanoate percussors is tolerant to lattice defects and therefore achieves comparable film thickness to vacuum depositions.Further indicated by positron annihilation spectroscopy,the RENiO_(3)grown by MOD exhibit large amount of lattice defects that improves their hydrogen incorporation amount and electron transfers,as demonstrated by the resonant nuclear reaction analysis and near edge X-ray absorption fine structure analysis.This effectively enlarges the magnitude in the resistance regulations in particular for RENiO_(3)with lighter RE,shedding a light on the extrinsic regulation of the hydrogen induced quantum transitions for correlated oxides semiconductors kinetically via defect engineering. 展开更多
关键词 metal-insulator transition rare earth nickelates lattice defects hydrogen incorporation metal-organic decomposition
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Tuning composite solid-state electrolyte interface to improve the electrochemical performance of lithium-oxygen battery
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作者 Hao Ouyang Shan Min +6 位作者 Jin Yi Xiaoyu Liu Fanghua Ning Jiaqian Qin yong jiang Bing Zhao Jiujun Zhang 《Green Energy & Environment》 SCIE EI CAS CSCD 2023年第4期1195-1204,共10页
Thin and flexible composite solid-state electrolyte(SSE) is considered to be a prospective candidate for lithium-oxygen(Li-O_(2)) batteries with the aim to address the problems of unsatisfied safety, terrible durabili... Thin and flexible composite solid-state electrolyte(SSE) is considered to be a prospective candidate for lithium-oxygen(Li-O_(2)) batteries with the aim to address the problems of unsatisfied safety, terrible durability as well as inferior electrochemical performance. Herein, in order to improve the safety and durability, a succinonitrile(SN) modified composite SSE is proposed. In this SSE, SN is introduced for eliminating the boundary between ceramic particles, increasing the amorphous region of polymer and ensuring fast ionic transport. Subsequently, the symmetric battery based on the proposed SSE achieves a long cycle life of 3000 h. Moreover, the elaborate cathode interface through the SN participation effectively reduces the barriers to the combination between lithium ions and electrons, facilitating the corresponding electrochemical reactions.As a result, the solid-state Li-O_(2)battery based on this SSE and tuned cathode interface achieves improved electrochemical performance including large specific capacity over 12,000 m Ah g^(-1), enhanced rate capacity as well as stable cycle life of 54 cycles at room temperature. This ingenious design provides a new orientation for the evolution of solid-state Li-O_(2)batteries. 展开更多
关键词 Solid-state Li-O_(2)battery Composite electrolyte Cathode interface Room temperature SUCCINONITRILE
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Role of biochemical markers and autoantibodies in diagnosis of early-stage primary biliary cholangitis
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作者 Yu-Jin Zhu Jing Li +5 位作者 yong-Gang Liu yong jiang Xiao-Jing Cheng Xu Han Chun-Yan Wang Jia Li 《World Journal of Gastroenterology》 SCIE CAS 2023年第34期5075-5081,共7页
BACKGROUND Primary biliary cholangitis(PBC)is a chronic progressive autoimmune cholestatic disease.The main target organ of PBC is the liver,and nonsuppurative inflammation of the small intrahepatic bile ducts may eve... BACKGROUND Primary biliary cholangitis(PBC)is a chronic progressive autoimmune cholestatic disease.The main target organ of PBC is the liver,and nonsuppurative inflammation of the small intrahepatic bile ducts may eventually develop into cirrhosis or liver fibrosis.AIM To explore the clinical characteristics of early-stage PBC,identify PBC in the early clinical stage,and promptly treat and monitor PBC.METHODS The data of 82 patients with PBC confirmed by pathology at Tianjin Second People’s Hospital from January 2013 to November 2021 were collected,and the patients were divided into stage I,stage II,stage III,and stage IV according to the pathological stage.The general data,serum biochemistry,immunoglobulins,and autoimmune antibodies of patients in each stage were retrospectively analyzed.RESULTS In early-stage(stages I+II)PBC patients,50.0%of patients had normal alanine aminotransferase(ALT)levels,and 37.5%had normal aspartate aminotransferase(AST)levels.For the remaining patients,the ALT and AST levels were mildly elevated;all of these patients had levels of<3 times the upper limit of normal values.The AST levels were significantly different among the three groups(stages I+II vs stage III vs stage IV,P<0.05).In the early stage,29.2%of patients had normal alkaline phosphatase(ALP)levels.The remaining patients had different degrees of ALP elevation;6.3%had ALP levels>5 times the upper limit of normal value.Moreover,γ-glutamyl transferase(GGT)was more robustly elevated,as 29.2%of patients had GGT levels of>10 times the upper limit of normal value.The ALP values among the three groups were significantly different(P<0.05).In early stage,the jaundice index did not increase significantly,but it gradually increased with disease progression.However,the above indicators were significantly different(P<0.05)between the early-stage group and the stage IV group.With the progression of the disease,the levels of albumin and albumin/globulin ratio tended to decrease,and the difference among the three groups was statistically significant(P<0.05).In early-stage patients,IgM and IgG levels as well as cholesterol levels were mildly elevated,but there were no significant differences among the three groups.Triglyceride levels were normal in the early-stage group,and the differences among the three groups were statistically significant(P<0.05).The early detection rates of anti-mitochondria antibody(AMA)and AMA-M2 were 66.7%and 45.8%,respectively.The positive rate of anti-sp100 antibodies was significantly higher in patients with stage IV PBC.When AMA and AMA-M2 were negative,in the early stage,the highest autoantibody was anti-nuclear antibody(ANA)(92.3%),and in all ANA patterns,the highest was ANA centromere(38.5%).CONCLUSION In early-stage PBC patients,ALT and AST levels are normal or mildly elevated,GGT and ALP levels are not elevated in parallel,GGT levels are more robustly elevated,and ALP levels are normal in some patients.When AMA and AMA-M2 are negative,ANA especially ANA centromere positivity suggests the possibility of early PBC.Therefore,in the clinic,significantly elevated GGT levels with or without normal ALP levels and with ANA(particularly ANA centromere)positivity(when AMA and AMA-M2 are negative)may indicate the possibility of early PBC. 展开更多
关键词 Primary biliary cholangitis Early stage Biochemical makers AUTOANTIBODIES Pathology
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AdaptNF: Adaptive service chain scheduling with stateless migration and NF consolidation
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作者 Qing Li He Huang +1 位作者 yong jiang Jingpu Duan 《Digital Communications and Networks》 SCIE CSCD 2023年第2期462-472,共11页
The combination of network function virtualization and software-defined networking allows various network functions to process flows according to their characteristics and requirements.Due to the highly dynamic nature... The combination of network function virtualization and software-defined networking allows various network functions to process flows according to their characteristics and requirements.Due to the highly dynamic nature of the workload,the network infrastructure needs to properly schedule the underlying resources in order to respond to workload changes in a timely manner.However,the existing NFV platform lacks a comprehensive solution for how to scale under workload variation,which may seriously hurt the overall system performance.To improve the scalability of the NFV platform and ensure consistent high performance under dynamic workloads,we propose AdaptNF,a novel NFV platform designed to support a combination of course-grained and fine-grained resource scheduling strategies.To deal with resource imbalance,which is the essential scheduling problem that leads to insufficient NFV performance,AdaptNF adopts a novel algorithm that can efficiently balance the workload among multiple network function instances through stateless flow migration.Our controlled experiments show that the AdaptNF scheme can optimize resource allocation and ensure outstanding performance after scaling.In terms of network throughput and latency,AdaptNF significantly improves the performance of the underlying NFV platform. 展开更多
关键词 Network function virtualization Software-defined networking Service chain Flow migration Dynamic scale
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Filtering for SNPs with high selective constraint augments mid-parent heterosis predictions in wheat(Triticum aestivum L.)
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作者 Abhishek Gogna Jie Zhang +3 位作者 yong jiang Albert W.Schulthess Yusheng Zhao Jochen C.Reif 《The Crop Journal》 SCIE CSCD 2023年第1期166-176,共11页
To extend the contemporary understanding into the grain yield heterosis of wheat, the current study investigated the contribution of deleterious alleles in shaping mid-parent heterosis(MPH). These alleles occur at low... To extend the contemporary understanding into the grain yield heterosis of wheat, the current study investigated the contribution of deleterious alleles in shaping mid-parent heterosis(MPH). These alleles occur at low frequency in the genome and are often missed by automated genotyping platforms like SNP arrays. The deleterious alleles herein were detected using a quantitative measurement of evolutionary conservation based on the phylogeny of wheat and investigations were made to:(1) assess the benefit of including deleterious alleles into MPH prediction models and(2) understand the genetic underpinnings of deleterious SNPs for grain yield MPH using contrasting crosses viz. elite × elite(Exp. 1) and elite × plant genetic resources(PGR;Exp. 2). In our study, we found a lower allele frequency of moderately deleterious alleles in elites compared to PGRs. This highlights the role of purifying selection for the development of elite wheat cultivars. It was shown that deleterious alleles are informative for MPH prediction models: modelling their additive-by-additive effects in Exp. 1 and dominance as well as associated digenic epistatic effects in Exp. 2 significantly boosts prediction accuracies of MPH. Furthermore,heterotic-quantitative trait loci's underlying MPH was investigated and their properties were contrasted in the two crosses. Conclusively, it was proposed that incomplete dominance of deleterious alleles contributes to grain yield heterosis in elite crosses(Exp. 1). 展开更多
关键词 Hybrid wheat Genomic evolutionary rate profiling Deleterious SNP Heterotic Quantitative trait loci
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Progress in research on tumor microenvironment-based spatial omics technologies
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作者 FANGMEI XIE NAITE XI +12 位作者 ZEPING HAN WENFENG LUO JIAN SHEN JINGGENG LUO XINGKUI TANG TING PANG YUBING LV JIABING LIANG LIYIN LIAO HAOYU ZHANG yong jiang YUGUANG LI JINHUA HE 《Oncology Research》 SCIE 2023年第6期877-885,共9页
Spatial omics technology integrates the concept of space into omics research and retains the spatial information of tissues or organs while obtaining molecular information.It is characterized by the ability to visuali... Spatial omics technology integrates the concept of space into omics research and retains the spatial information of tissues or organs while obtaining molecular information.It is characterized by the ability to visualize changes in molecular information and yields intuitive and vivid visual results.Spatial omics technologies include spatial transcriptomics,spatial proteomics,spatial metabolomics,and other technologies,the most widely used of which are spatial transcriptomics and spatial proteomics.The tumor microenvironment refers to the surrounding microenvironment in which tumor cells exist,including the surrounding blood vessels,immune cells,fibroblasts,bone marrow-derived inflammatory cells,various signaling molecules,and extracellular matrix.A key issue in modern tumor biology is the application of spatial omics to the study of the tumor microenvironment,which can reveal problems that conventional research techniques cannot,potentially leading to the development of novel therapeutic agents for cancer.This paper summarizes the progress of research on spatial transcriptomics and spatial proteomics technologies for characterizing the tumor immune microenvironment. 展开更多
关键词 Spatial omics Spatial transcriptomics Spatial proteomics Tumor microenvironment
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QoS-Aware Congestion Control with Online Learning
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作者 Lei Zhang Kewei Zhu +1 位作者 yong Cui yong jiang 《China Communications》 SCIE CSCD 2023年第2期168-178,共11页
In emerging applications such as industrial control and autonomous driving,end-to-end deterministic quality of service(QoS)transmission guarantee has become an urgent problem to be solved.Internet congestion control a... In emerging applications such as industrial control and autonomous driving,end-to-end deterministic quality of service(QoS)transmission guarantee has become an urgent problem to be solved.Internet congestion control algorithms are essential to the performance of applications.However,existing congestion control schemes follow the best-effort principle of data transmission without the perception of application QoS requirements.To enable data delivery within application QoS constraints,we leverage an online learning mechanism to design Crimson,a novel congestion control algorithm in which each sender continuously observes the gap between current performance and pre-defined QoS.Crimson can change rates adaptively that satisfy application QoS requirements as a result.Across many emulation environments and real-world experiments,our proposed scheme can efficiently balance the different trade-offs between throughput,delay and loss rate.Crimson also achieves consistent performance over a wide range of QoS constraints under diverse network scenarios. 展开更多
关键词 congestion control quality of service online learning
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Papillary thyroid carcinoma with nodular fasciitis-like stroma-an unusual variant with distinctive histopathology:A case report
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作者 Jun Hu Fei Wang +1 位作者 Wei Xue yong jiang 《World Journal of Clinical Cases》 SCIE 2023年第24期5797-5803,共7页
BACKGROUND Papillary thyroid carcinoma(PTC)is regarded as a fairly common endocrine malignancy,which can be divided into different multiple variants due to wide morphologic differences.The majority of PTC variants hav... BACKGROUND Papillary thyroid carcinoma(PTC)is regarded as a fairly common endocrine malignancy,which can be divided into different multiple variants due to wide morphologic differences.The majority of PTC variants have been reported,but PTC with nodular fasciitis-like stroma(NFS)is a rare pathological variant and has been infrequently reported in the relevant literature.This condition involves abundant reactive stromal components rich in spindle cells,which may account for 60%-80%of the tumor along with a typical papillary carcinoma.CASE SUMMARY A 44-year-old man presented with a 4-mo history of a palpable mass over the anterior aspect of the left neck,the tumor demonstrated gradual enlargement but was painless during the 4 mo prior to discovery.Thyroid function test results were normal.Physical examination showed an enormous and firm nodular mass in the left lobe of the thyroid gland extending to the level of the hyoid bone.Ultrasonography of the neck revealed a well-defined heterogeneous lesion measuring around 5.0 cm×4.0 cm with a hypoechoic complex nodule,decreased vascularity and speckles of microcalcification.The patient underwent left thyroidectomy with central compartment lymph node dissection.Final histopathological examination confirmed the diagnosis of PTC with extensive fibromatosis-like stroma combined with typical PTC.The patient was asymptomatic at the 3-mo follow-up.CONCLUSION PTC-NFS is a rare pathological variant and its diagnosis and prognosis may be similar to typical papillary carcinoma. 展开更多
关键词 Papillary thyroid carcinoma Nodular fasciitis-like stroma Spindle cell METAPLASIA Neck ultrasound Differential diagnosis Case report
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Cr、Ti掺杂Cu/石墨烯界面结合性能的第一性原理预测(英文) 被引量:5
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作者 刘洋 王刚 +2 位作者 王怡人 江勇 易丹青 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2019年第8期1721-1727,共7页
基于密度泛函理论,对过渡金属Cr、Ti掺杂的Cu/石墨烯界面结合性能进行第一性原理预测,构建并对比一系列不同Cu/石墨烯界面的三明治和表面模型。计算结果表明,界面位相关系对界面结合强度影响不大。两种界面模型的计算结果均显示top-fcc... 基于密度泛函理论,对过渡金属Cr、Ti掺杂的Cu/石墨烯界面结合性能进行第一性原理预测,构建并对比一系列不同Cu/石墨烯界面的三明治和表面模型。计算结果表明,界面位相关系对界面结合强度影响不大。两种界面模型的计算结果均显示top-fcc配位模型是最稳定的界面结构,并具有较低的界面结合能。Cr掺杂倾向于偏析到界面上取代Cu,而Ti惨杂倾向于占据界面处的填隙位。虽然这两种元素的偏析趋势都较弱,其偏析可以显著提高界面的结合性能,从而强化界面。 展开更多
关键词 石墨烯 掺杂 界面 第一性原理
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Structural Characteristics and Evolution Process of the Metamorphic Buried Hill: A Case of BZ Oilfield in Bohai Bay, China
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作者 Hua Zheng Xuwei Bie +2 位作者 Xinfei Song yong jiang Wenchao Liu 《International Journal of Geosciences》 2022年第1期1-11,共11页
Bozhong oilfield which is abbreviated as BZ oilfield is the first oilfield with deep metamorphic buried hill that is discovered reserves of billion-ton in Bohai Bay. Affected by multi-stage tectonic movements, the dis... Bozhong oilfield which is abbreviated as BZ oilfield is the first oilfield with deep metamorphic buried hill that is discovered reserves of billion-ton in Bohai Bay. Affected by multi-stage tectonic movements, the distribution of fractures is very complex in this area, therefore it is significant to study the evolution of structures for understanding the distribution of fractures. In view of the complexity on the tectonic evolution of the buried hill region in the study area, the influence of tectonic movements on the formation of fractured reservoir is analyzed, and the research results lay the foundation for the efficient development in this type of the oilfield. The results show that main faults, which is formed during early Indosinian and Yanshanian period, are mainly developed in the BZ oilfield area, and the fracture strike has mainly east-west and north-east-east trend. Based on the analysis of the relationship among tectonic evolution, regional stress field and fracture development, it is considered that Indosinian extrusion is the main reason for the formation of main direction faults in the study area. Yanshanian strike-slip transformation and Himalayan reactivation further controlled the development of the fractured reservoirs in the later stage, and formed the present fracture network system. Well block 5 is located in passive plate system during Indosinian period, it is affected by Himalayan stretching and long-term activation of large faults in the later stage, so that the effective fractures are relatively developed. The result plays an important role in guiding the overall plan deployment of the BZ oilfield. 展开更多
关键词 Bohai Bay BZ Oilfield Metamorphic Rock Buried Hill Tectonic Evolution STRESS
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Existence of Traveling Waves in Lattice Dynamical Systems
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作者 Xiaojun Li yong jiang Ziming Du 《Journal of Applied Mathematics and Physics》 2016年第7期1231-1236,共6页
Existence of traveling wave solutions for some lattice differential equations is investigated. We prove that there exists  c<sub>*</sub>>0 such that for each c≥c*</sub>, the systems und... Existence of traveling wave solutions for some lattice differential equations is investigated. We prove that there exists  c<sub>*</sub>>0 such that for each c≥c*</sub>, the systems under consideration admit monotonic nondecreasing traveling waves. 展开更多
关键词 Traveling Wave Lattice Dynamical Systems Schauder’s Fixed Point Theorem
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密排六方钛中基面堆垛层错导致的孪晶界滑移、孪生台阶及孪晶生长:第一性原理研究 被引量:3
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作者 钱琦 刘正卿 +3 位作者 江勇 王怡人 安星龙 宋旼 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第2期382-390,共9页
基于第一性原理计算研究密排六方结构钛中{101n}共格孪晶界和滑移孪晶界的结构和能量,探讨滑移孪晶界的形成机理及其与孪晶生长的关系。结果表明,共格孪晶界与基面堆垛层错的相互作用可使共格孪晶界产生滑移,从而形成对应的滑移孪晶界... 基于第一性原理计算研究密排六方结构钛中{101n}共格孪晶界和滑移孪晶界的结构和能量,探讨滑移孪晶界的形成机理及其与孪晶生长的关系。结果表明,共格孪晶界与基面堆垛层错的相互作用可使共格孪晶界产生滑移,从而形成对应的滑移孪晶界。这种滑移最终能在孪晶界处形成一对单层孪生台阶,并恢复共格孪晶界的结构。孪生台阶的塞积可导致高分辨率透射电镜观察到的孪晶界上的台阶宽化,进一步促进孪晶的生长。此外,还评估多种合金化元素对孪晶界滑移的钉扎效应,为钛合金的强化设计提供指导。 展开更多
关键词 孪晶界 层错 孪生台阶 孪晶生长 第一性原理
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改进朴素贝叶斯算法在火灾预警中的应用 被引量:3
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作者 贺香勇 蒋勇 胡勇 《中国科学技术大学学报》 CAS CSCD 北大核心 2022年第6期48-56,I0003,共10页
为解决实际场景中传统火灾预警系统识别准确率低的问题,提出了一种新的朴素贝叶斯(NB)算法,即改进朴素贝叶斯(INB)。用基于属性权重和正交矩阵相结合的优化方法对NB加以改进。属性权重考虑了每个决策类别下各个属性的不同取值对分类性... 为解决实际场景中传统火灾预警系统识别准确率低的问题,提出了一种新的朴素贝叶斯(NB)算法,即改进朴素贝叶斯(INB)。用基于属性权重和正交矩阵相结合的优化方法对NB加以改进。属性权重考虑了每个决策类别下各个属性的不同取值对分类性能的影响,正交矩阵弱化了属性间的线性关系,降低了属性间的关联性,使其更贴近条件属性独立性假设。利用美国国家标准与技术研究院(NIST)有关火灾研究的报告资料作为仿真数据,构建了八个不同规模的数据集,滤波、归一化处理后用于INB的训练与测试。十次十折交叉验证结果表明,当数据集中含190组样本时,INB已得到有效训练,并展示出稳F_(1)定的火灾预警能力。换句话说,INB可以在小样本下得到充分训练。选取支持向量机(SVM)、反向传播(BP)神经网络和NB进行对比研究,结果表明,新改进的INB算法的识别正确率、平均查准率、平均召回率和平均值在四种算法中最高,分别为96.1%、97.3%、97.2%和97.3%。此外,与其他算法相比,INB在具有更好性能的情况下,其训练时间更短,响应迅速。综上所述,INB具有良好且稳定的火灾预警性能,可以作为火灾预警系统的核心算法。 展开更多
关键词 改进朴素贝叶斯(INB) 条件独立性假设 小样本数据 识别准确率 火灾预警
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普惠性学前教育的内涵辨析与发展路径创新 被引量:51
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作者 姜勇 李芳 庞丽娟 《学前教育研究》 CSSCI 北大核心 2019年第11期13-21,共9页
全面建设普惠性学前教育公共服务体系是我国近中期关于学前教育事业的重要战略规划和部署,但是对于"何谓普惠性学前教育",目前人们的认识还未完全统一,由政府政策、学术研究、社会公众表达的三种话语形态对"何谓普惠性... 全面建设普惠性学前教育公共服务体系是我国近中期关于学前教育事业的重要战略规划和部署,但是对于"何谓普惠性学前教育",目前人们的认识还未完全统一,由政府政策、学术研究、社会公众表达的三种话语形态对"何谓普惠性学前教育"的解读存在较大分歧,影响了各地普惠性学前教育公共服务体系的建设。基于教育公平的价值追求,普惠性学前教育应当包括"付得起""达得到""配得齐""顾得广""适得度"五个方面的内涵,其中"付得起"指对于不同收入群体来说收费合理,可以接受;"达得到"指家庭可以较低的交通成本通过便捷的交通方式把幼儿从居所送到园所;"配得齐"指幼儿园配备的设施数量与质量有保证;"顾得广"指面向所有儿童,实现"广覆盖";"适得度"指坚持"适度普惠"的基本原则,分层次、有重点地推进普惠性学前教育公共服务体系建设。从此内涵出发,除了要坚持大力扶持、兴办公办性质幼儿园的传统路径之外,各地在建设普惠性学前教育公共服务体系的过程中还应创新发展路径,强调"特惠先行"的着力方向,积极设立面向贫困家庭、弱势家庭的中国版"开端计划",落实"强在起点"的教育强国梦。 展开更多
关键词 普惠性学前教育 学前教育公共服务体系 教育公平
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MgO中间层增强Mg/石墨烯界面结合性能的第一性原理预测和分析 被引量:1
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作者 王维澄 刘金龙 +4 位作者 赵晗晗 袁秋红 罗岚 江勇 刘勇 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第2期472-482,共11页
石墨烯增强镁基复合材料面临镁/石墨烯界面结合弱的难题。本文作者采用第一性原理计算评估通过引入原位生成的MgO中间层来改善Mg/石墨烯结合的可行性。计算的界面结合强度由高到低的顺序为Mg(0001)/MgO(111)>MgO(111)/石墨烯>Mg(0... 石墨烯增强镁基复合材料面临镁/石墨烯界面结合弱的难题。本文作者采用第一性原理计算评估通过引入原位生成的MgO中间层来改善Mg/石墨烯结合的可行性。计算的界面结合强度由高到低的顺序为Mg(0001)/MgO(111)>MgO(111)/石墨烯>Mg(0001)/石墨烯。Mg/MgO/石墨烯界面结合的增强可以归因于在Mg/MgO和MgO/石墨烯界面上新形成的离子键和共价键的强烈相互作用取代了原来镁和石墨烯之间极弱的范德华力作用。 展开更多
关键词 镁基复合材料 石墨烯 氧化镁 界面 第一性原理
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