基于流固耦合作用的砂岩地浸采铀效果数值模拟分析

为探究低渗砂岩铀矿在不同因素下的产量变化情况,根据储层有效应力与渗流特性的关系,建立有效应力-渗流数值模型。通过日产水量分析流固耦合作用下储层的产量变化规律,并结合变异系数法分析注入压力、初始渗透率和井间距对产量的影响。研究表明：考虑流固耦合作用下的储层产量会更快进入稳定状态,产量更高;应力敏感性系数越大,有效应力减小对地层渗透率影响越明显。注入压力越大,地层有效应力减小区域下降幅度增大,使地层渗透率增大区域升高幅度增大,导致产量逐渐增多;流固耦合作用下产量随着初始渗透率增大而增多且增长速度较快;流固耦合作用下,随着井间距的增大,注采井间有效应力减小的影响减弱,注采井间渗透率增大趋势也在下降,导致产量逐渐降低。结合各因素变异系数变化可得,注入压力对产量效果影响更明显。本研究有助于建立完整的砂岩铀矿地浸采铀生产方案。     

Uranium Superconductivity Redux

Since the discovery of heavy-fermion superconductivity in uranium compounds in the early 1980s, other uranium compounds have been discovered that are fully as interesting to study. However, as we look forward in the year 2000, we now have higher-purity, single crystals of the element itself. Preliminary resistivity and ac susceptibility measurements show the improved quality of the samples and thus hold the promise of understanding many aspects of its superconductivity, which have remained untouched for almost 25 years.     

某铀矿井场抽注液控制的数字化技术应用

在地浸采铀生产过程中,控制抽注液平衡和高效识别抽注液异常状态是保障浸出效能和井场的安全重要措施。以内蒙古某铀矿为例,介绍了该铀矿抽注液平衡联动控制与抽注液异常监测方面数字化技术的应用情况,探讨了应用数字化技术前后该铀矿山抽注液管控效能的变化。结果表明,应用数字化技术进行抽注液平衡控制能有效解决抽注液调控过程中人工控制所存在的劳动强度大、调控不及时和精度不足的问题;合理的模型设计能够高效识别抽注液异常状态。建立抽注液数字化管控体系有助于实现精益化管控、提升井场生产效能、降低安全风险。     

Gate-induced drain leakage in FD-SOI devices: What the TFET teaches us about the MOSFET

This paper compares the gate-induced drain leakage (GIDL) in fully-depleted (FD) silicon-on-insulator (SOI) tunneling field effect transistor (TFET) and in standard metal-oxide-semiconductor FET (MOSFET) fabricated in the same process. The measurements show that the MOSFET GIDL current is lower than the GIDL in a TFET with the same junction doping, especially for devices with thick gate oxide and under low drain bias. A model describing lateral band-to-band tunneling (BTBT) is developed for GIDL in the FD-SOI TFET. By combining the model of gate-controllable tunneling diode in series with a field effect diode, we achieve an accurate picture of GIDL in FD-SOI MOSFETs.     

薄膜全耗尽SOICMOS器件和电路

对全耗尽 SOI(FD SOI) CMOS器件和电路进行了研究 ,硅膜厚度为 70 nm.器件采用双多晶硅栅结构 ,即NMOS器件采用 P+多晶硅栅 ,PMOS器件采用 N+多晶硅栅 ,在轻沟道掺杂条件下 ,得到器件的阈值电压接近0 .7V.为了减小源漏电阻以及防止在沟道边缘出现空洞 (V oids) ,采用了注 Ge硅化物工艺 ,源漏方块电阻约为5 .2Ω /□ .经过工艺流片 ,获得了性能良好的器件和电路 .其中当工作电压为 5 V时 ,0 .8μm 10 1级环振单级延迟为 45 ps     

Investigation of pillar thickness variation effect on oblique rotating implantation (ORI)-based vertical double gate MOSFET

The rapid scaling of integrated circuit requires further shrinkage of lateral device dimension, which correlates with pillar thickness in vertical structure. This paper investigates the effect of pillar thickness variation on vertical double gate MOSFET (VDGM) fabricated using oblique rotating ion implantation (ORI) method. For this purpose, several scenarios of silicon pillar thickness t_si were evaluated for 20–100 nm channel length. The source region was found to merge at pillar thickness below 75 nm, which results in floating body effect and creates isolated region in the middle of pillar. The vertical devices using ORI method show better performance than those with conventional implantation method for all pillar thickness, due to the elimination of corner effect that degrades the gate control. The presence of isolated depletion region in the middle of pillar at floating body increases parasitic effect for higher drain potential. By further reduction of pillar thickness towards fully depleted feature, the increase in gate-to gate charge coupling improves the performance of ORI-based vertical double gate MOSFET, as evident in near-ideal swing value and lower DIBL, compared to the partially depleted and body-tied device.     

PDSOI体源连接环形栅nMOS特性研究

提出了一种基于部分耗尽绝缘体上硅的体源连接环形栅nMOS器件,并讨论了相应的工艺技术和工作机理。采用体源连接环形栅器件结构,有效地抑制了浮体环形栅器件中存在的浮体效应和寄生双极晶体管效应,使器件性能得到很大的提高。消除了浮体环形栅器件的反常亚阈值斜率和Kink效应,DIBL从120.7mV/V降低到3.45mV/V,关态击穿电压从4.8V提高到12.1V。最后指出,体源连接环形栅器件非常适合于抗辐照加固等应用领域。     

隐埋层中二维效应对全耗尽SOI非对称HALO结构阈值电压的影响

在非对称HALO结构的全耗尽SOI二维阈值电压解析模型的基础上,对阈值电压受隐埋层中二维效应的影响进行了讨论.通过与一维模型的比较,说明在深亚微米SOI MOSFET器件中隐埋层的二维效应会导致器件提前出现短沟道效应.新模型结果与二维数值模拟软件MEDICI吻合较好.     

原地浸出采铀中若干技术问题的探讨

阐述了地浸采铀的溶浸动力学特征 ,论述了浸出液铀质量浓度变化及井场的合理布局     

内蒙古新城子火山盆地遥感解译及铀成矿预测

内蒙古新城子火山盆地位于大兴安岭南端及扎兰屯火山岩型铀成矿远景带南端,盆地内中生代火山活动频繁且强烈,主要发育火山岩型铀矿。笔者利用Landsat ETM及高分一号遥感数据,对研究区进行了系统构造解译及蚀变信息提取,结合已有地质资料,初步确定了研究区以NE、NW、近EW、近NS向4组线性构造为构造格架。最终根据构造、铀矿化、遥感蚀变等信息圈定3处找矿远景区,期望为该区下一步铀矿地质找矿工作提供依据。