On the reverse short‐channel effect and threshold voltage roll‐off controls for 90 nm node MOSFETs

Abstract

In order to let device designers tune the short channel behavior of MOSFETs, a method is proposed in this work to demonstrate how to use LDD (lightly doped drain) and pocket implants to control RSCE (reverse short channel effect) and threshold voltage (V_t ) roll‐off. The method is based on the process parameters and silicon data of the 90 nm node technology of UMC (United Microelectronics Corporation). With the help of computers, 17 different process conditions of 8 different gate lengths were simulated using ISE TCAD to collect V_t variation data. Four characteristics representing the short channel behaviors of the MOSFETs were designed and extracted from the simulated data. Their empirical equations were also established subsequently. After verification, those mathematical models were demonstrated to help device designers in choosing the most suitable LDD and pocket implant parameters to generate required V_t characteristics.     

体位的改变干预手术患者血压的变化

目的探讨食管癌手术患者体位的变化对血压的干预,预防循环系统的并发症确保患者安全。方法将100例常规侧卧90°体位的食管癌手术患者随机分组,Ⅰ组:手术结束麻药停用后患者从侧卧90°体位→侧卧45°体位→平卧位时不同阶段的血压变化;Ⅱ组手术完毕麻药停用后,患者从侧卧90°体位转变为平卧位1、2、3min时血压变化情况。结果侧卧90°体位→侧卧45°体位→平卧位逐步转变体位时血压变化不大,P<0.05,差异无显着意义。侧卧90°转变为平卧位时血压有不同程度的下降,尤其在转变为平卧位1min时下降最为显著,P<0.05。结论手术结束麻醉停止后侧卧位转变为平卧位时应采用循序渐进的方法逐步放平患者身体即由侧卧90°体位→侧卧45°体位→平卧位血压无明显变化,而由侧卧位直接转变为平卧位时血压的变化明显。     

腹腔镜联合米非司酮治疗未破裂型宫角妊娠探讨

目的探讨腹腔镜手术联合米非司酮在宫角妊娠未破裂型治疗中的价值。方法回顾性2007年1月至2010年12月收治的宫角妊娠27例临床资料，总结开腹手术、腹腔镜、腹腔镜联合米非司酮治疗宫角妊娠的效果。结果腹腔镜手术联合米非司酮治疗成功率达100％，与直接腹腔镜手术比较具有术中出血少、手术时间短、术后恢复快的优点。结论腹腔镜联合米非司酮治疗宫角妊娠安全有效。     

X100管线钢冷裂纹敏感性研究

采用插销试验方法研究了埋弧焊条件下X100管线钢热影响区的冷裂纹敏感性及断口特性.试验结果表明,X100管线钢在不预热条件下对冷裂纹不敏感,临界断裂应力σcr为823.5 MPa,与其抗拉强度Rm (823 MPa)相当,可在不预热条件下焊接.当拘束应力继续增大时,发生时效断裂,断口性质为典型的氢致延迟断裂.X100级...     

腹腔镜胆囊大部分切除术术中处理冰冻样胆囊床及胆囊三角的手术技巧和体会

目的总结腹腔镜胆囊大部分切除术术中处理冰冻样胆囊床及胆囊三角的手术技巧及体会。方法回顾分析2005年8月至2011年8月为58例长期反复炎症发作使胆囊组织严重疤痕化,胆囊床、胆囊三角呈冰冻样改变的患者施行腹腔镜胆囊大部分切除术的临床资料。结果 53例成功完成腹腔镜胆囊大部分切除术,3例中转开腹,2例术后合并胆总管结石,行内镜逆行胰胆管造影取石后治愈。结论腹腔镜胆囊大部分切除术术中采用适当的手术技巧,可安全的处理冰冻样胆囊床及胆囊三角。     

Thermosensitive chitosan hydrogel for implantable drug delivery: Blending PVA to mitigate body response and promote bioavailability

Thermosensitive hydrogels promise to be the injectable implants for long-term controlled drug release; however, body response to the implanted hydrogels and its unpredictable impacts on drug release complicates their applications. In the present study, hydrophilic polymer poly(vinyl alcohol) (PVA) was blended into the thermosensitive hydrogel composed of chitosan and glycerophosphate to mitigate the body responses and promote the drug bioavailability. The effects of PVA on the surface properties of the hydrogel were evaluated by zeta-potential, water contact angle, and cell attachment. Body responses were explored by histological examination via subcutaneously implanting the hydrogels into Sprague-Dawley rats. Drug release in vivo and bioavailability were determined with cyclosporine A (CsA) employed as the model drug. The results showed that, on one hand, the presence of PVA improved the surface hydrophilicity of the hydrogel and inhibited the cell attachment on the hydrogel, which alleviated the further cell infiltration and tissue integration in body; and on the other hand, blending of PVA led to the more rapid gel formation and more compact network, which resisted the dehydration and survived the hydrogel from cell division. These advantages benefited the controlled release and absorption of CsA, and contributed to the higher drug bioavailability. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Hydroxyapatite-Reinforced Polyamide 6,6 Nanocomposites through Melt Compounding

Hydroxyapatite-reinforced polyamide 6,6 nanocomposites were prepared for load-bearing bone implant applications. Nanoparticles of hydroxyapatite (nHAp) were synthesized through a wet chemical reaction and were incorporated into the polymer melt at different loading fractions by melt compounding so as to sensitively modulate the mechanical properties of the latter. Tensile properties of the nanocomposites were found to be substantially improved at filler loading fractions as low as 3 wt%. Theoretical calculations also confirm the improved extent of reinforcement for nanocomposites over the predicted data for conventional micro counterparts. Differential scanning calorimetry studies revealed that the melting and crystallization characteristics of the polyamide matrix were unaltered with the incorporation of nHAp. However, the addition of nanohydroxyapatite considerably influenced the thermal stability of the nanocomposites.     

Application of rapid prototyping and rapid tooling for development of patient-specific craniofacial implant: an investigative study

In today’s competitive world, the life-style of the average human being has become very fast. This causes a huge number traffic accidents resulting in various types of injuries. In India, most of these accidents take place during bike riding and this causes different types of fracture of bones. One of these injuries is head injury. For the proper treatment of such patients, demands for patient-specific craniofacial bio-implants are increasing day by day. This kind of ‘tailored’ implant development through near net shape manufacturing is a highly challenging task since the developmental time and cost has to be as low as possible. At the Central Mechanical Engineering Research Institute (CMERI), one such process of implant development was explored taking one case of head injury. The implant was developed through the “3D CAD-rapid prototyping (RP)-rapid tooling (RT)-investment casting (IC)” route. For achieving the task, only the facilities available at CMERI were utilized.     

Development of porous Ti6Al4V samples by microsphere sintering

Two differently sized microspheres were sintered at 1300 °C and 1400 °C from 2 to 8 h in stoneware, alumina, yttria and zirconia moulds. Selecting the appropriate material to be used as a mould remains a critical issue given titanium's high reactivity at elevated temperatures. Optimum mechanical properties were obtained when sintering the smallest microspheres in yttria-coated moulds. Stiffness of the samples was lower than 40% of that of the bulk solid material, which comes closer to that of human cortical bone. Open and interconnected porosity was observed in all the specimens.     

碳/碳复合材料的生物相容性及生物应用

碳／碳复合材料继承了碳大有的生物相容性，又具有优良的力学性能，在生物医用材料领域有很大的应用前景。本文总结了医用碳碳／复合材料的研究现状，评述了碳／碳复合材料的生物相容性特点，并详细讨论了碳／碳复合材料生物医用所涉及到的模量、界面及表面改性等问题，对碳／碳复合材料的医用前景进行了展望。