Role of environmental and annealing conditions on the passivation-free in-Ga–Zn–O TFT

We examined the characteristics of passivation-free amorphous In–Ga–Zn–O thin film transistor (a-IGZO TFT) devices under different thermal annealing atmospheres. With annealing at higher temperature, the device performed better at the above-threshold operation region, which indicated the film quality was improved with the decrease of defects in the a-IGZO active region. The mobility, threshold voltage and subthreshold swing of a-IGZO TFT annealed at 450 °C was 7.53 cm²/V s, 0.71 V and 0.18 V/decade, respectively. It was also observed that the a-IGZO was conductive after thermal annealing in the vacuum, due to the ease of oxygen out-diffusion from the a-IGZO back channel. The oxygen deficiency resultantly appeared, and provided leaky paths causing electrical unreliability when TFT was turned off. In contrast, the annealing atmosphere full of O₂ or N₂ would suppress the oxygen diffusion out of the a-IGZO back channel. The worst V_th degradation of a-IGZO TFT after positive gate bias stress and negative gate bias stress (NGBS) was about 2 V and ? 2 V, respectively. However, the V_th shift in the NGBS testing could be suppressed to ? 0.5 V in vacuum chamber. Material analysis methods including X-ray photoelectron spectroscopy and scanning electron microscopy were used to investigate the change of a-IGZO film after different thermal annealing treatments. The variation of O 1s spectra with different annealing atmospheres showed the consistence with our proposed models.     

Gene Expression Profile in Primary Tumor Is Associated with Brain-Tropism of Metastasis from Lung Adenocarcinoma

Lung adenocarcinoma has a strong propensity to metastasize to the brain. The brain metastases are difficult to treat and can cause significant morbidity and mortality. Identifying patients with increased risk of developing brain metastasis can assist medical decision-making, facilitating a closer surveillance or justifying a preventive treatment. We analyzed 27 lung adenocarcinoma patients who received a primary lung tumor resection and developed metastases within 5 years after the surgery. Among these patients, 16 developed brain metastases and 11 developed non-brain metastases only. We performed targeted DNA sequencing, RNA sequencing and immunohistochemistry to characterize the difference between the primary tumors. We also compared our findings to the published data of brain-tropic and non-brain-tropic lung adenocarcinoma cell lines. The results demonstrated that the targeted tumor DNA sequencing did not reveal a significant difference between the groups, but the RNA sequencing identified 390 differentially expressed genes. A gene expression signature including CDKN2A could identify 100% of brain-metastasizing tumors with a 91% specificity. However, when compared to the differentially expressed genes between brain-tropic and non-brain-tropic lung cancer cell lines, a different set of genes was shared between the patient data and the cell line data, which include many genes implicated in the cancer-glia/neuron interaction. Our findings indicate that it is possible to identify lung adenocarcinoma patients at the highest risk for brain metastasis by analyzing the primary tumor. Further investigation is required to elucidate the mechanism behind these associations and to identify potential treatment targets.     

A comparative study of combustibility and surface flammability of building materials

Results are presented of a project to evaluate the combustibility and surface flammability of building interior finish materials commonly used in Taiwan. The project was conducted at the Fire Laboratory of the Architecture and Building Research Institute in Taipei. Eighteen different wall-covering materials were tested according to Chinese National Standard (CNS) 6532, which is equivalent to Japanese Industry Standard (JIS) 1321, and according to ASTM E 1354-92 (Cone calorimeter). A comparison of test results is presented, and a qualitative relationship is developed between the performance in the two methods. The classification system for degrees of combustibility developed in Canada by Richardson and Brooks was hereby used to group materials based in performance in the ASTM test method. © 1997 John Wiley & Sons, Ltd.     

Experimental determination of the hydrodynamic coefficients of an underwater manipulator

A single degree‐of‐freedom (DOF) manipulator arm with a rectangular cross section is built to investigate the hydrodynamic effects, including drag force, added mass, and the moments induced by these forces. The drag–velocity relationships (linear and angular) are experimentally established and the drag force/moment coefficients are deduced. The added mass and the added moment of inertia are determined for the first time through the relationship between the added mass of the manipulator and its acceleration. These data are very useful for developing the dynamic model and therefore the optimum control of underwater manipulators. ©1999 John Wiley & Sons, Inc.     

大型衡器现场检定的标准砝码替代法——衡器检定中非常规的方法之一

衡器检定通常是采用直接加砝码法。但在一些实际检定中,有时需要采取某些非常规的方法,标准砝码的替代法就是方法之一。标准砝码的替代法即解决了检定现场砝码不足的问题。又满足了进行量传的要求。     

Impact Initiated Annular Retonation Wave in explosive

Experiments conducted at the White Oak Laboratory with a pentolite explosive charge impacted by a flat-ended cylinder of mild steel, showed a hole drilled at the center of the impactor, if the explosive was detonated. A computer simulation was carried out with the finite element hydrocode DEFEL and the Forest-Fire reaction-rate model. Computed results verified the hypothesis that the annular retonation was the cause of the drilled hole. The detonation started at a distance of about 10 mm from the impact surface, then developed into an annular shape and propagated inwards and backwards, to the axis of symmetry and the impact surface. The converging wave generated a pressure of about 100 GPa near the center of its impact surface, which is believed to be the real cause of the hole.     

A generalized methodology for determining the total heat gain through building envelopes

We present a generalized methodology for determining the annual total heat gain through external walls and proofs of large air-conditioned buildings. The methodology is based on the concept of the overall thermal transfer value (OTTV). Respective OTTV equations for building envelopes and roofs are developed through parametric simulations using the DOE-2 computer code. The equations are valid for buildings having different aspect ratios and wall masses. Appropriate coefficients for heat conduction through fenestrations and opaque walls and solar correction factors for wall facades of different orientations are computed from local weather data. The equations allow building designers to make accurate estimates of the total heat gain for the purpose of evaluating energy-efficient building envelope components and air-conditioning systems and plant options. The methodology is validated using DOE-2 computed heat gain results and can be applied to different classes of buildings, construction types and locations.     

近距离煤层采区巷道地压显现特点

实践表明,采区巷道的地压显现是受岩石物理力学性质、开采深度、煤层倾角、地质构造、巷道位置、开采程序和支护方式影响的。本文以近距离煤层采区巷道地压实测资料为依据,揭示了巷道地压显现规律,阐明了合理巷道布置问题和改善巷道维护的措施。     

ABSORPTION OF NO BY NaClO2 SOLUTION: PERFORMANCE CHARACTERISTICS

The absorption of lean NO (200 ∼ 1000 ppm) gases in aqueous NaClO₂ solution was investigated in both a mechanically stirred vessel and a packed tower. The chemical reaction rate between NO and NaClO₂ in alkaline solution was shown to be second-order with respect to NO concentration and first-order to NaClO₂ concentration. After including mass transfer considerations, the absorption rate equation established in this work (under the condition of NaClO₂ concentration less than 1.0 M and temperature at 30°C) is given as:

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In addition, a robust design method was also used to study the performance of this de NO_x process by NaClO₂ solution in a packed tower. S/N analysis of the results indicated that the pH of liquor, NaClO₂ concentration and NaOH concentration were the major factors in affecting both NO oxidation and absorption efficiencies.     

腔体式吸收器与真空管吸收器的热性能比较

本文分析了槽形抛物镜聚光集热器中管族结构和环套结构的腔体式吸收器以及真空吸收器的热物理特征,画出其热阻网络,建立太阳能一般性控制方程,并以此为依据对这三种吸收器的热性能进行了数值分析比较。