Narrowed Si_(0.7)Ge_(0.3)channel FinFET with subthreshold swing of64 mV/Dec using cyclic self-limited oxidation and removal process

A narrowed Si_(0.7)Ge_(0.3)channel fin field-effect transistor(FinFET)device is demonstrated in detail by using an accuratecyclic wet treatment process.The Si_(0.7)Ge_(0.3)fin/per side of 0.63 nm in thickness can be accurately removed in each cycleby utilizing a self-limited oxidation with 40%HNO_(3)solution in 40 s and oxidation removal can be achieved with 1%HFsolution in 10 s.As a result,after the dummy gate removal,the fin width of Si_(0.7)Ge_(0.3)can be narrowed from 20 nm to 8 nmby utilizing 10 cycles of this wet treatment process.Compared with the conventional Si_(0.7)Ge_(0.3)FinFET under a similarprocess,the narrowed Si_(0.7)Ge_(0.3)channel FinFET can realize a strong gate control capability by using this newly developedwet treatment process,because its subthreshold slope can be reduced by 24%,improving from 87 mV/dec to 64 mV/dec.

Dynamic analysis of lymphocyte subsets of peripheral blood in patients with acute self-limited hepatitis B

Purpose: To investigate dynamic changes and significance of lymphocyte subsets (T lymphocytes, B lymphocytes, NK cells and T cell subsets) of peripheral blood in patients with acute self-limited hepatitis B (AHB). Methods: Immune cells of peripheral blood were compared among 17 cases of self-limited acute hepatitis B patients, 36 patients with chronic hepatitis B (CHB) and 32 healthy controls by flow cytometry (FCM). CD4+/CD8+ was monitored dynamically, meanwhile relations between T lymphocyte subsets and ALT and clearance of HBV DNA were explored. Results: Dynamic changes of lymphocyte subsets were found in AHB, the level of CD3+T cells was significantly higher compared to CHB group and healthy control group. Frequencies of CD3+CD4+ T cells in the third and fourth week and CD4+/CD8+ in the second week were higher compared to other groups. Frequ- ency of NK cells was low and was significantly lower compared to other groups in the third week specially. It was showed that CD4+/CD8+ was low followed by high abnormal ALT during early stage by dynamic monitoring of CD4+/CD8+, and CD4+/CD8+ was increasing accompanied by normal ALT set by set, but CD4+/CD8+ had no significant relation to ALT and HBV DNA. Conclusion: Immune status of AHB, compared to CHB and healthy controls, was significantly different and dynamic changes of lymphocyte sub- sets may be related to progress of disease.

Two-dimensional modeling of the self-limiting oxidation in silicon and tungsten nanowires

Self-limiting oxidation of nanowires has been previously described as a reaction- or diffusion-controlled process. In this letter, the concept of finite reactive region is introduced into a diffusion-controlled model, based upon which a two-dimensional cylindrical kinetics model is developed for the oxidation of silicon nanowires and is extended for tungsten. In the model, diffusivity is affected by the expansive oxidation reaction induced stress. The dependency of the oxidation upon curvature and temperature is modeled. Good agreement between the model predictions and available experimental data is obtained. The de- veloped model serves to quantify the oxidation in two-dimensional nanostructures and is expected to facilitate their fabrication via thermal oxidation techniques.

Preparation of Self-limiting Heating Cables with Excellent Processability, Mechanical Properties and PTC Effect via Thermal and Electrical Treatments

Polymer/conductive filler composites have been widely used for the preparation of self-limiting heating cables with the positive temperature coefficient (PTC) effect. The control of conductive filler distribution and network in polymer matrix is the most critical for performance of PTC materials. In order to compensate for the destruction of the filler network structure caused by strong shearing during processing, an excessive conductive filler content is usually added into the polymer matrix, which in turn sacrifices its processability and mechanical properties. In this work, a facile post-treatment of the as-extruded cable, including thermal and electrical treatment to produce high-density polyethylene (HDPE)/carbon black (CB) cable with excellent PTC effect, is developed. It is found for the as-extruded sample, the strong shearing makes the CB particles disperse uniformly in HDPE matrix, and 25 wt% CB is needed for the formation of conductive paths. For the thermal-treated sample, a gradually aggregated CB filler structure is observed, which leads to the improvement of PTC effect and the notable reduction of CB content to 20 wt%. It is very interesting to see that for the sample with combined thermal and electrical treatment, CB particles are agglomerated and oriented along the electric field direction to create substantial conductive paths, which leads to a further decrease of CB content down to 15 wt%. In this way, self-limiting heating cables with excellent processability, mechanical properties and PTC effect have simultaneously been achieved.

Virological course of hepatitis A virus as determined by real time RT-PCR: Correlation with biochemical, immunological and genotypic profiles

AIM： To undertake analysis of hepatitis A viral load, alanine aminotransferase （ALT）, and viral genotypes with duration of viremia, and to correlate these parameters with CD4^＋/ CD8^＋ lymphocyte populations that control cell-mediated immunity. METHODS： Cell counts were carried out using fresh whole blood collected in EDTA vials using a fluorescence activated cell sorter. Hepatitis A virus （HAV） RNA was extracted from blood serum, reverse transcribed into cDNA and quantified by Real-Time polymerase chain reaction and was genotyped. RESULTS： Among 11 patients, 10 could be analyzed completely. Of these, 3 had severe acute hepatitis （s-AH） and the remainder had a self-limited acute hepatitis A （AHA）, with one patient with fulminant disease （encephalopathy Grade IV） dying on the 4^th d. The ALT level was significantly higher both in AHA （1070.9±894.3; P = 0.0014） and s-AH （1713.9±886.3; P = 0.001） compared to normal controls （23.6±7.2）. The prothrombin time in s-AH patients （21.0 ±2.0; P=0.02） was significantly higher than in AHA （14.3±1.1;P = 0.44）. The CD4^＋/CD8^＋ ratio in AHA patients （1.17 ＋ 0.11; P = 0.22） and s-AH （0.83 ＋ 0.12; P = 0.0002） were lower than seen in normal healthy controls （1.52）. Self-limited cases had peak viral load at the beginning of analysis while in s-AH patients this occurred at the 15TM or 30^th d. In acute and severe groups, one patient each belonged to genotype IA, with the remaining 8 cases belonging to genotype IIIA. The only fulminant hepatic failure case belonged to genotype IA. HAV viral load and AIT values collected during the entire course of the selflimited infection were directly correlated but this was not the case for s-AH patients.CONCLUSION： Based on a small-scale study, the persistently higher viral load of s-AH might be due to diminished cellular immunity and hemolysis. The duration of viremia was dependent on the host, as the viral genotype had no apparent role in clinical outcome of AVH and s-AH cases.

Polymorphisms of microsomal triglyceride transfer protein in different hepatitis B virus-infected patients

AIM: To identify the two polymorphisms of microsomal triglyceride transfer protein (MTP) gene in the Chinese population and to explore their correlation with both hepatitis B virus (HBV) self-limited infection and persistent infection. METHODS: A total of 316 subjects with self-limited HBV infection and 316 patients with persistent HBV infection (195 subjects without familial history), matched with age and sex, from the Chinese Han population were enrolled in this study. Polymorphisms of MTP at the promoter region -493 and at H297Q were determined by the allele specific polymerase chain reaction (PCR). RESULTS: The ratio of males to females was 2.13:1 for each group and the average age in the self-limited and chronic infection groups was 38.36 and 38.28 years, respectively. None of the allelic distributions deviated significantly from that predicted by the Hardy-Weinberg equilibrium. There was a linkagedisequilibrium between H297Q and -493G/T (D’ = 0.77). As the χ2 test was used, the genotype distribution of MTP -493G/T demonstrated a significant difference between the self-limited infection group and the entire chronic group or the chronic patients with no family history (χ2 = 8.543, P = 0.015 and χ2 = 7.199, P = 0.019). The allele distribution at the MTP-493 position also demonstrated a significant difference between the study groups without family history (χ2 = 6.212, P = 0.013). The T allele emerged as a possible protective factor which may influence the outcomes of HBV infection (OR: 0.59; 95% CI: 0.389-0.897). CONCLUSION: The polymorphism of the MTP gene, T allele at -493, may be involved in determining the HBV infection outcomes, of which the mechanism needs to be further investigated.

人工智能化教育中的个体发展悖论及其疏解

人工智能技术融入教育打造了教育的全新样态。丰富的教育资源、多元的教育方式和自适应的教育过程,有助于受教育者优选内容、提高效率和凸显个性。然而,人工智能化教育在促进个体发展方面存在明显的悖论:个体发展方向的自决与自弃;个体发展空间的广阔与偏狭;个体发展过程的整全与割裂。突破这些悖论,人工智能化教育需要超越技术框定,坚守自为的育人立场,在个体发展限度内推动个体的自由与解放。

Plasma atomic layer etching of GaN/AlGaN materials and application: An overview

With the development of the third generation of semiconductor devices,it is essential to achieve precise etching of gallium nitride(GaN)materials that is close to the atomic level.Compared with the traditional wet etching and continuous plasma etching,plasma atomic layer etching(ALE)of GaN has the advantages of self-limiting etching,high selectivity to other materials,and smooth etched surface.In this paper the basic properties and applications of GaN are presented.It also presents the various etching methods of GaN.GaN plasma ALE systems are reviewed,and their similarities and differences are compared.In addition,the industrial application of GaN plasma ALE is outlined.

Early Stage of Oxidation on Titanium Surface by Reactive Molecular Dynamics Simulation

Understanding of metal oxidation is very critical to corrosion control,catalysis synthesis,and advanced materials engineering.Metal oxidation is a very complex phenomenon,with many different processes which are coupled and involved from the onset of reaction.In this work,the initial stage of oxidation on titanium surface was investigated in atomic scale by molecular dynamics(MD)simulations using a reactive force field(ReaxFF).We show that oxygen transport is the dominant process during the initial oxidation.Our simulation also demonstrate that a compressive stress was generated in the oxide layer which blocked the oxygen transport perpendicular to the Titanium(0001)surface and further prevented oxidation in the deeper layers.The mechanism of initial oxidation observed in this work can be also applicable to other self-limiting oxidation.

Multi-functional stainless steel composite frames stabilize the sodium metal battery

The sodium(Na)metal battery has the prospect of promising high energy density and sustainable tech-nology for low-cost energy storage.However,the soft texture and high reactivity of Na cause it easy to structure collapse and produce side reactions with organic electrolytes.Inspired by ancient Chinese ar-chitecture,a structural engineering strategy is introduced to conquer the above issues.PVDF film-covered stainless steel mesh(SMPF)embedded in the obverse of Na metal to form a“self-limiting”Na/electrolyte interface and bare stainless steel mesh(SM)with high electronic conductivity embedded in the reverse of Na metal to form a uniformly electronic distributed Na/collector interface.Based on the electric field simulation and in-situ optical tests,the well-designed structure of the SM@Na@SMPF electrode can re-strict the dendrite growth and slow down the bubbles release.The above strategies provide important technical support for the large-scale application of flexible Na metal batteries.

Ultrathin molybdenum disulfide(MoS_(2)) film obtained in atomic layer deposition: A mini-review

Atomic layer deposition(ALD) as a flexible surface-controlled fabrication technique has attracted widespread interest in numerous nanotechnology applications, which can obtain ultrathin or two-dimensional molybdenum disulfide(2D MoS2) films.The ALD technique possesses the characteristics of precise thickness control, excellent uniformity, and conformality, relying on the self-limiting surface reaction. In this mini-review, the knowledge about the fabrication mechanisms and applications of ALD prepared MoS2 films is reviewed. The surface reaction pathway about ALD synthesis MoS2 is elaborated, and the corresponding factors causing saturation adsorption are discussed. Two possible growth mechanisms of ALD-MoS2 film based on the building blocks and MoS2 islands are compared. For both, the deposition process of MoS2 can be divided into two stages, heterogeneous deposition stage and homogeneous deposition stage. The mismatch between the as-deposited MoS2 in the heterodeposition and the lattice structure of the substrate surface is a key factor leading to the poor crystallinity of as-deposited MoS2. In addition, the extensions of ALD MoS2 technique to improve the as-deposited film quality are discussed. Finally, the applications of ALD deposited MoS2 film are summarized, and future perspectives are outlined.