Characterization of in-situ terahertz detection by optical interaction in a periodically poled stoichiometric lithium tantalate nonlinear crystal

Terahertz waves are generated using a femtosecond laser pulse in a periodically poled stoichiometric lithium tantalate crystal and simultaneously detected via a non-collinear optical parametric interaction inside the same crystal. Real time up-conversion signal between the generated THz and an optic probe pulses is measured depending on the beam overlapped conditions using a general silicon-photodiode for the THz detection. The non-collinear geometry is to facilitate manipulated property of the position-dependent bandwidth at narrow and broad bandwidths of 45 GHz and 3.3 THz, respectively at the one crystal. Furthermore, an aperture effect at the detection part is characterized as the function of size and position owing to the spatial distribution of the frequency conversion signal and it is applied in optimization of the in-situ detection scheme.     

分布式空调系统适用性评价研究

介绍了分布式空调系统适用性评价的基本原理,调研获取了适用性评价的基本一级指标,给出了各个评价指标的获取方法并建立了计算模型,举例说明了该方法的可用性.     

黄土包气带水分运移的现场研究

本文主要介绍在核素迁移试验现场进行的黄土包气带水分运移研究的方法和主要结果.包气带水分运移试验场建有一座9.0m深的负压计观测竖井和二个28.0m深的中子仪测管.分别采用WM-1型负压计系统和IHiii型土壤中子水分仪测量黄土剖面的基质势和含水量.一组负压计和中子仪测管在天然条件下测量,连续观测2年多,用于水分运移特征研究;另一组测量停止淹灌后的水分再分配过程,连续观测7个月,用于非饱和渗透系数测定.结果表明: (1)降雨入渗主要影响深度、蒸发影响深度在1.0m以上; (2)水分运移可分为4个带:1.0m深度以上为强交替带,含水量、水势和水势梯度随时间变化快、变幅大,液态水的运移比较明显;1.0～7.2m深度上为含水量和水势随时间变化小的弱交替带,除黄土颗粒大小变化较大的深度处,一般来说,水势梯度方向单向向下,其中:含水量和水势在1.0～1.6m深度上随时间变化较大,液态水的运移也比较明显;在5.0～7.2m深度上,水分变化很小,基本趋于稳定状态,液态水的运移很不明显,微弱的热水汽扩散显现出来;在7.2～23.0m深度上,含水量除在黄土-古土壤-钙质结核层组合交界处有变化外,其余则基本保持与黄土颗粒大小变化相对应的稳定状态,为水分运移的传递带;23.0～28.0m深度上为毛管水带; (3)在0.4～2.4m深度上,当体积含水量θ为0.18～0.41时,非饱和渗透系数K(cm/d)为3.6×10-3～23.4,拟合得到K与θ的经验关系式:K＝2.81×105θ10.51,它可适用于含水量在此范围内的马兰黄土上段; (4)在水分运移的基本稳定带(5.0～7.2m深度),应用达西方程并采取年平均方法,估算得到年降雨入渗补给量不到1cm; (5)在半干旱黄土地区,热水汽的扩散也可能是地下水的一种补给方式.     

Characterization of the Interactions between Cereal Flour and “Nata Puree” in Batter

This study aimed to characterize the interactions between cereal flour (rice, wheat, and barley) and “nata puree” (NP), a disintegrated bacterial cellulose (BC) in the presence of a water-soluble polysaccharide, with powder-dispersion activity. Pasting properties of cereal flour with additives were analyzed using a Rapid Visco Analyzer, and disintegrated BC in water (BCW), three water-soluble polysaccharides: (1,3)(1,4)-β-glucan, tamarind seed gum, and birchwood xylan, and the corresponding NPs were used as additives. For rice flour, additional BCW or NPs increased the initial and the peak viscosity. The addition of water-soluble polysaccharides produced the opposite trend: viscosity increased from the peak time to the end of measurements. For wheat flour, the addition of BCW or NP delayed the peak time and increased peak viscosity; the increase was maintained till the end of measurements. For barley flour, the additional BCW or NP caused a higher gelatinization rate and increased viscosity at the starch-retrogradation stage. Next, static gelatinization of a rice flour suspension in NP was successfully accomplished before placing it in a vessel; NP concentration in the gel significantly affected the firmness. Thus, the dynamic and unique interactions between various cereal flours and cell-wall polysaccharides in NPs can increase the flours'' potential; static gelatinization of cereal flour with NP could expand flours'' application range in both current and next-generation cooking.     

A brush device with visual and haptic feedback for virtual painting of 3D virtual objects

We have previously developed a mixed reality (MR) painting system with which a user could take a physical object in the real world and apply virtual paint to it. However, this system could not provide the sensation of painting on virtual objects in MR space. Therefore, we subsequently proposed and developed mechanisms that simulated the effect of touch and movement when a brush device was used to paint on a virtual canvas. In this paper, we use visual and haptic feedback to provide the sensation of painting on virtual three-dimensional objects using a new brush device called the MAI Painting Brush++. We evaluate and confirm its effectiveness through several user studies.     

Occlusion-free animation of driving routes for car navigation systems

This paper presents a method for occlusion-free animation of geographical landmarks, and its application to a new type of car navigation system in which driving routes of interest are always visible. This is achieved by animating a nonperspective image where geographical landmarks such as mountain tops and roads are rendered as if they are seen from different viewpoints. The technical contribution of this paper lies in formulating the nonperspective terrain navigation as an inverse problem of continuously deforming a 3D terrain surface from the 2D screen arrangement of its associated geographical landmarks. The present approach provides a perceptually reasonable compromise between the navigation clarity and visual realism where the corresponding nonperspective view is fully augmented by assigning appropriate textures and shading effects to the terrain surface according to its geometry. An eye tracking experiment is conducted to prove that the present approach actually exhibits visually-pleasing navigation frames while users can clearly recognize the shape of the driving route without occlusion, together with the spatial configuration of geographical landmarks in its neighborhood.     

IL-18 up-regulates perforin-mediated NK activity without increasing perforin messenger RNA expression by binding to constitutively expressed IL-18 receptor

IL-18 is a powerful inducer of IFN-gamma production, particularly in collaboration with IL-12. IL-18, like IL-12, also augments NK activity. Here we investigated the molecular mechanism underlying the up-regulation of killing activity of NK cells by IL-18. IL-18, like IL-12, dose dependently enhanced NK activity of splenocytes. This action was further enhanced by costimulation with IL-12. Treatment with anti-IL-2R Ab did not affect IL-18- and/or IL-12-augmented NK activity, and splenocytes from IFN-gamma-deficient mice showed enhanced NK activity following stimulation with IL-12 and/or IL-18. Splenocytes from the mice deficient in both IL-12 and IL-18 normally responded to IL-18 and/or IL-12 with facilitated NK activity, suggesting that functional NK cells develop in the absence of IL-12 and IL-18. IL-18R, as well as IL-12R mRNA, was constitutively expressed in splenocytes from SCID mice, which lack T cells and B cells but have intact NK cells, and in those from IL-12 and IL-18 double knockout mice. NK cells isolated from SCID splenocytes expressed IL-18R on their surface. IL-18, in contrast to IL-12, did not enhance mRNA expression of perforin, a key molecule for exocytosis-mediated cytotoxicity. However, pretreatment with concanamycin A completely inhibited this IL-18- and/or IL-12-augmented NK activity. Furthermore, IL-18, like IL-12, failed to enhance NK activity of splenocytes from perforin-deficient mice. These data suggested that NK cells develop and express IL-12R and IL-18R in the absence of IL-12 or IL-18, and that both IL-18 and IL-12 directly and independently augment perforin-mediated cytotoxic activity of NK cells.     

Evaluation of the Enzymatic Saccharification Efficiency of an Energy Crop,Erianthus arundinaceus,Pretreated with Ca(OH)2 Using both Countercurrent Washing System and pH Adjustment by Nonpressurized CO2

Erianthus arundinaceus (ER) is greatly appreciated among domestic energy crops in Japan for the production of fermentable sugars from lignocellulosic polysaccharides. In this study, we developed an efficient Ca(OH)₂-based pretreatment of both stems and leaves of ER at ambient temperature with the addition of a washing step for enzymatic saccharification. The recoveries of glucans and xylans in the pretreated ER after four countercurrent washing cycles were 91 and 76 %, respectively, the former being considerably higher than that of rice straw (RS) (72 %). Their saccharification ratios in the washed sample under the pressure of 1 atm CO₂ were 80 and 92.5 %, respectively. The application of this simple sugar production process from ER would further support the domestic bioprocess development. ER is also foreseen to provide the additional feedstock favorable for harvesting from winter to spring in Japan, preventing a risk for feedstock shortage generated by single harvesting such as RS.     

Modification of Chiral Monodentate Phosphine Ligands (MOP) for Palladium‐Catalyzed Asymmetric Hydrosilylation of Cyclic 1,3‐Dienes

Several MOP ligands 5 containing aryl groups at 2′ position of (R)‐2‐(diphenylphosphino)‐1,1′‐binaphthyl skeleton were prepared and used for palladium‐catalyzed asymmetric hydrosilylation of cyclic 1,3‐dienes 6 with trichlorosilane. Highest enantioselectivity was observed in the reaction of 1,3‐cyclopentadiene ( 6a ) catalyzed by a palladium complex (0.25 mol %) coordinated with (R)‐2‐(diphenylphosphino)‐2′‐(3,5‐dimethyl‐4‐methoxyphenyl)‐1,1′‐binaphthyl ( 5f ), which gave (S)‐3‐(trichlorosilyl)cyclopentene of 90% ee.     

Study on decomposition gas for diagnostics of gas‐insulated transformers

Concentrations of population and business activities result in high energy demand in urban areas. This requires the construction of underground substations. Oil‐free, nonflammable, nonexplosive equipment is recommended for underground substations. For this reason, gas‐insulated transformers have been developed. A diagnostic method for gas‐insulated transformers is thus required. This paper provides an experimental survey of the main components of decomposition gas generated by various faults in gas‐insulated transformers carried out through simplified model tests. The phenomena of overheating and partial discharges are modeled, taking the actual materials related to each fault into account. For example, CO, CO₂, and aldehydes are produced by overheating of pressboards and PET films. The amount of gas produced increases with rising temperature. While various gases are produced from a partial discharge, the principal components are SO₂ and SOF₂. These results will be used to develop a diagnostic method for gas‐insulated transformers. © 1999 Scripta Technica, Electr Eng Jpn, 130(1): 48–58, 2000