A novel process to form cobalt silicided p+ poly-Sigates by BF2+ implantation into bilayeredCoSi/a-Si films and subsequent anneal

A novel process that implants BF₂⁺ ions into thin bilayered CoSi/a-Si films has been shown to form cobalt silicided p ⁺ poly-Si gates with excellent gate oxide integrity and very small flatband shift. The effects of not only using the CoSi layer as an implantation barrier but also keeping the a-Si underlayer during the initial silicide formation both significantly suppress the boron penetration through thin gate oxide     

侧钻井防砂工艺技术

针对铡钻井井身结构的特点，简要介绍了两种稠油侧钻井防砂技术的机理和内容。其中，在小直径筛管防砂技术中，防砂筛管和封隔器的设计是主要的；而通过室内试验证明，高温人工井壁完全能够满足现场防砂要求。     

On the kinetics of carbon nanotube growth by thermal CVD method

The role of ammonia (NH₃) on obtaining good quality vertically aligned multi-walled carbon nanotubes (CNTs) in thermal chemical vapor deposition (CVD) method has been widely studied. It was generally agreed that NH₃ helps to maintain catalyst metal surface active by reacting with amorphous carbon. In this article, a systematic study in varying the temperature and mixing ratio of gases was conducted in order to clarify the role of NH₃ and revealed a criterion for optimized condition window in the growth processes. In addition, this study has also carried out a statistical analysis through intensive TEM observations on the tube diameters, bamboo spacing, and the formation rate of each diaphragm under various temperatures and carbon source/NH₃ ratios. While the formation of the separation diaphragms were indeed a result of bulk diffusion of carbon atoms from bottom of the Ni nanoparticle following thermal dehydrogenization to the top of the Ni nanoparticle, there were other carbon atoms diffusing presumably via surface diffusion to the CNT-metal interface and contributed to the growth of tube wall; in other words, the CNTs growth is simultaneous renucleation and growth processes, instead of a continuous renucleation and growth process. This kinetics-based mechanism in combination with the proposed role of NH₃ could not only successfully explain the effects of the process parameters including temperature and the mixing gas ratio, but also could be used for pursuing the goal of lower growth temperature for thermal CVD method which is very important for many applications of CNTs.     

Curcumin provides potential protection against the activation of hypoxia and prolyl 4-hydroxylase inhibitors on prostate-specific antigen expression in human prostate carcinoma cells

Scope: Prostate‐specific antigen (PSA) is a well‐known marker for diagnosing and monitoring prostate cancer. Curcumin, a yellow curry pigment, has been reported to enhance androgen receptor (AR) degradation. We examined the effects of curcumin on increasing PSA expression by hypoxia and prolyl hydroxylase inhibitors, L ‐mimosine and dimethyloxalylglycine (DMOG), in human prostate carcinoma LNCaP cells. Methods and results: The ³H‐thymidine incorporation assay revealed that either L ‐mimosine or DMOG treatments attenuated cell proliferation. Immunoblot and enzyme‐linked immunosorbent assays (ELISA) indicated that both L ‐mimosine and DMOG have an effect similar to hypoxia, which stabilized hypoxia‐inducible factor‐1α (HIF‐1α) and induced PSA gene expression. The results of the immunoblot and transient gene expression assays indicated that induction of the PSA expression by hypoxia is both HIF‐1α‐ and AR‐dependent. Immunoblot assays revealed that a curcumin treatment (10 μM) decreased the protein abundance of AR but did not significantly affect the protein levels of HIF‐1α and vascular endothelial growth factor, which were induced by hypoxia. ELISA and transient gene expression assays indicated that curcumin blocked the activation of L ‐mimosine or DMOG treatment on PSA expression. Conclusions: These results indicate that curcumin blocked the enhanced effect of PSA expression by L ‐mimosine and DMOG that induce hypoxia condition.     

Submicron-meter tunneling field-effect poly-Si thin-film transistors with a thinned channel layer

Submicron-meter poly-Si tunneling-effect thin-film transistor (TFT) devices with a thinned channel layer have been investigated. With reducing the gate length to be shorter than 1 μm, the poly-Si TFT device with conventional MOSFET structure is considerably degraded. The tunneling field-effect transistor (TFET) structure can be employed to alleviate the short channel effect, thus largely suppressing the off-state leakage. However, for a poly-Si channel layer of 100 nm thickness, the TFET structure causes a small on-state current, which may not provide well sufficient driving current. By reducing the channel layer thickness to be 20 nm, the on-state current for the TFET structure can be largely increased, due to the enhanced bending of energy band for a thinned channel layer. As a result, for the TFET poly-Si TFTs at a gate bias of 5 V and a drain bias of 3 V, a 20-nm channel layer leads to an on-state current of about 1 order larger than that by a 100-nm channel layer, while still keeping an off-state leakage smaller than 0.1 pA/μm. Accordingly, the submicron-meter TFET poly-Si TFT devices with a thinned channel layer would show good feasibility for implementing high packing density of poly-Si TFT devices.     

A process simplification scheme for fabricating CMOS polycrystalline-Si thin film transistors

A process simplification scheme for fabricating CMOS poly-Si thin-film transistors (TFTs) has been pro-posed, which employs large-angle-tilt-implantation of dopant through a gate sidewall spacer (LATITS). By this LATITS scheme, a lightly doped drain region under the oxide spacer is formed by low-dose tilt implantation of phosphorus (orboron) dopant through the spacer, and then the n+-source/drain (n+-S/D) (or p+-S/D) region is formed via using the same photo-mask layer during CMOS integration. For both n-TFT and p-TFT devices, as compared to the sample with conventional single n+-S/D (or p+-S/D) structure, the LATITS scheme can cause an obviously smaller leakage current, due to more gradual dopant distribution and thus smaller electric field. In addition, the resultant on-state currents only show slight degradation for the LATITS scheme, As a result, by the LATITS scheme, CMOS poly-Si TFT devices with an on/off current ratio well above 8 orders may be achieved without needing extra photo-mask layers during CMOS integration.     

Fast computation of achievable feedback performance in mixed sensitivityH^{∞}design

The computational bottleneck of theH^{infty}design has been recognized to be the "ε-iteration," a computationally demanding direct search of the minimum achievableH^{infty}performance. Verma and Jonckheere showed that the optimalH^{infty}performance can be characterized as the spectral radius of the so-called "Toeplitz plus Hankel" operator. Even before the appearance of the "Toeplitz plus Hankel" operator in theH^{infty}setting, the same operator had already been shown to play a crucial role in the spectral theory of the linear-quadratic problem developed by Jonckheere and Silverman. In this paper, we exploit this common "Toeplitz plus Hankel" operator structure shared by the seemingly unrelated linear-quadratic andH^{infty}problems, and we construct fast state-space algorithms for evaluating the spectral radius of the "Toeplitz plus Hankel" operator. The salient feature of the algorithm is that the spectral radius can be evaluated, with an accuracy predicted by an identifiable error bound, from the antistabilizing solution of the algebraic Riccati equation of the linear-quadratic problem associated with theHinftydesign.     

Antagonism of NMDA receptors but not AMPA/kainate receptors blocks bursting in dopaminergic neurons induced by electrical stimulation of the prefrontal cortex

Evidence suggests that the prefrontal cortex (PFC) plays an important role in the burst activity of midbrain dopaminergic (DA) neurons. In particular, electrical stimulation of the PFC elicits patterns of activity in DA neurons, closely time-locked to the stimulation, which resemble natural bursts. Given that natural bursts are produced by the activity of excitatory amino acid (EAA)-ergic afferents, if PFC-induced time-locked bursts are homologues of natural bursts, EAA antagonists should attenuate them. Hence, the NMDA (N-methyl-D-aspartate) antagonist CPP (3-((+/-)-2-carboxypiperazin-4-yl)propyl-1-phosphonic acid) and the AMPA (D,L-alpha-amino-3-hydroxy-5-methyl-4-isoxalone propionic acid)/kainate antagonist CNQX (6-cyano-7-nitroquinoxaline-2,3-dione) were applied by iontophoresis to DA neurons exhibiting time-locked bursts during PFC stimulation. CPP produced a significant reduction in time-locked bursting. In contrast, CNQX (at currents which antagonised AMPA responses) did not. These effects of CPP and CNQX on time-locked bursting mirror the effects previously reported for these drugs on natural bursting. Since natural bursting and bursting induced by PFC stimulation are both blocked selectively by CPP, the present results increase the degree of analogy between the two burst phenomena, thereby adding extra support to the contention that the cortex is involved in producing the natural bursting in DA neurons.