Optimized energy storage performance in BF-BT-based lead-free ferroelectric ceramics with local compositional fluctuation

BiFeO₃-based lead-free ferroelectric is considered a potential candidate for energy storage applications owing to its high spontaneous polarization. To tackle the compromise between high polarization and energy storage density, NaNbO₃ (NN) was introduced into 0.7BiFeO₃-0.3Ba(Hf_0.05Ti_0.95)O₃ (BF-BHfT) ceramics, where Nb⁵⁺ ions enter the BF-BHfT lattices and enhance resistivity, while Na⁺ ions occupied on the A-sites and smash the long-range ferroelectric order into polar nanoregions. Consequently, the ceramics could maintain high maximum polarization and low remanent polarization. High recoverable energy density (W_rec) of 5.2 J/cm³ and efficiency (88%) were recorded in 0.53BF-0.3BHfT-0.17NN ceramics. Besides, it exhibited good thermostability up to 120 °C (W_rec variation < 5%), frequency stability from 10 to 200 Hz (W_rec variation < 7%) and excellent fatigue resistance after 10⁴ cycles (W_rec variation < 0.2%). Under different electric fields the efficiency still maintains nearly constant. In charge-discharge test a W_dis of 3.7 J/cm³ was recorded, which proved 0.5³BF-0.3BHfT-0.17NN ceramics a promising candidate for energy storage applications.     

非均质三维模型水驱剩余油试验研究

为了明晰储层非均质性对水驱油采出程度的影响,运用人造物理模型制作技术制作了三维物理模型,并用恒速法对不同的三维非均质模型进行水驱油试验。试验发现:纵向非均质模型的水驱油采出程度最高,平面非均质模型的水驱油采出程度最低;平面非均质模型中2个渗透层间窜流是剩余油过多的主要因素,运用微凝胶调驱后,可改善水驱波及体积,大幅度提高采出程度。采用数值模拟方法,模拟了不同的三维非均质模型水驱油过程及其在不同含水阶段采出程度、剩余油分布情况。模拟结果表明,亲水反韵律模型水驱采出程度最高,剩余油分布均匀,各油层水洗程度也均匀;亲水正韵律模型水驱采出程度最低,剩余油集中分布在上部低渗透层段。剩余油的数量、分布情况受油层沉积韵律类型、重力作用、毛管力作用、油层渗透率、水驱强度等多种因素的制约。     

Remote sensing techniques for predicting evapotranspiration from mixed vegetated surfaces

Evapotranspiration (ET) is a key component of the hydrological cycle however it is also the most difficult factor to quantify. In recent decades, estimating ET has been improved by advances in remote sensing, particularly in agricultural studies. However, quantifying ET from mixed vegetation environs, particularly urban parklands, is still challenging due to the heterogeneity of plant species, canopy covers, microclimates, and because of costly methodological requirements. Several studies have recently been conducted in agriculture and forestry which may be useful for mixed landscape vegetation studies with some modifications. This review describes general remote sensing-based approaches to estimate ET and describes their advantages and disadvantages. Most of these approaches need extensive time investment, medium to high skill levels and are quite expensive. However, in addition to the reviewed methods, the authors recommend combining remotely sensed vegetation indices and ground-based techniques for ET estimation of mixed landscape vegetation such as urban parklands.     

盘古梁地区侏罗系油藏稳产技术研究

从盘古梁地区侏罗系油藏的开发特征出发,利用油藏工程及注采调整方法,总结该油藏合理的开发技术政策及注采调整技术,有效提高了该油藏的开发效果,为同类油藏的稳产提供可借鉴的依据。     

The Geostatistical Modeling of a Terminal Fan in the Lower Second Member of the Shahejie Formation

A large number of cores observations, analyses reveal that the sedimentary system of Wen25 block is terminal fan system. This area is now at a high water cut period, and the reservoir heterogeneity has affected the development. In order to accurately describe the reservoir, this paper built the structural model, the microfacies model using truncated Gaussian stochastic method and physical property model using facies-controlled technology. The comparison between facies-controlled and non-facies-controlled modeling reveals the former is more reliable in describing reservoir heterogeneity and can provide realistic and rational geological models for later numerical simulation and forecast.     

Analyzing heterogeneity in conjoint estimates of residential preferences

Conjoint estimates of residential preferencesare typically based on aggregate responses. Forreasons of segmentation or to differentiatebetween non-significant housing attributes andattributes that are characterized byconflicting preferences, further analysis isrequired. In this paper, the heterogeneity inthe conjoint estimates of residentialpreferences of families is analyzed. It isexamined how the estimated part-worth utilitiesof the housing attributes are related to thesocio-economic variables and current housingattributes by applying regression analysis.Although the explained variance was rather low,suggesting that residential preferences offamilies are highly idiosyncratic, therelationships that were significant could beinterpreted well.     

Exploring feature-based approaches in PET images for predicting cancer treatment outcomes

Accumulating evidence suggests that characteristics of pre-treatment FDG-PET could be used as prognostic factors to predict outcomes in different cancer sites. Current risk analyses are limited to visual assessment or direct uptake value measurements. We are investigating intensity-volume histogram metrics and shape and texture features extracted from PET images to predict patient's response to treatment. These approaches were demonstrated using datasets from cervix and head and neck cancers, where AUC of 0.76 and 1.0 were achieved, respectively. The preliminary results suggest that the proposed approaches could potentially provide better tools and discriminant power for utilizing functional imaging in clinical prognosis.     

Genome-Wide Investigation of Multifocal and Unifocal Prostate Cancer—Are They Genetically Different?

Prostate cancer is widely observed to be biologically heterogeneous. Its heterogeneity is manifested histologically as multifocal prostate cancer, which is observed more frequently than unifocal prostate cancer. The clinical and prognostic significance of either focal cancer type is not fully established. To investigate prostate cancer heterogeneity, the genetic profiles of multifocal and unifocal prostate cancers were compared. Here, we report observations deduced from tumor-tumor comparison of copy number alteration data of both focal categories. Forty-one fresh frozen prostate cancer foci from 14 multifocal prostate cancers and eight unifocal prostate cancers were subjected to copy number variation analysis with the Affymetrix SNP 6.0 microarray tool. With the investigated cases, tumors obtained from a single prostate exhibited different genetic profiles of variable degrees. Further comparison identified no distinct genetic pattern or signatures specific to multifocal or unifocal prostate cancer. Our findings suggest that samples obtained from multiple sites of a single unifocal prostate cancer show as much genetic heterogeneity and variability as separate tumors obtained from a single multifocal prostate cancer.     

油田高含水期窜流通道定量描述方法

油田开发进入高含水期,储层的非均质性和储层的敏感性导致孔喉增大,注入水沿着高渗透带形成窜流通道,严重地影响了开发效果。根据储层参数、微观孔隙结构的变化,阐述了综合分析窜流通道的定性方法。引入大孔道综合指数的概念,应用模糊综合评判的方法,定量识别了窜流通道的分布规律。     

分层多种示踪剂井间监测技术在坨11南断块的应用

简介了题示示踪剂井间监测技术的原理、示踪剂用量设计及所得资料解释方法。在胜坨油田11南断块沙二8砂层组,相隔22或23天,将3组不同的非分配型 分配型示踪剂分别注入3-9-271注水井的沙二81、沙二82、沙二83层,在周围生产不同层位的9口采油井进行监测。以沙二81层为例说明示踪剂产出浓度曲线拟合效果较好。监测资料表明沙二8层的平面和纵向非均质性均较强,有几口井内有窜槽现象。由监测资料确定了3个小层的主要水驱方向。通过监测数据的综合解释,得到该井组的井间高渗层渗透率、厚度、喉道半径、主流通道、波及体积及系数等储层参数,表明井间主流道均为长期注水冲刷形成的高渗层。井区非均质性强,83层尤其突出。根据综合解释结果修正地质模型,应用示踪数值模拟方法,得到了井组3个小层的剩余油饱和度分布图。图6表5参3。