掺模拟锌灰烬制陶:相转化和产品抗浸出性(英文)

Zinc is one of the hazardous metals commonly found in municipal solid waste incineration(MSWI) ash,and this study reveals the stabilization mechanisms when sintering zinc-laden ash and ceramic precursors as a waste-to-resource strategy.Using ZnO to simulate the zinc-laden ash and sintering with kaolinite and mullite ceramic precursors,both zinc aluminate spinel(ZnAl2O4) and willemite(Zn2SiO4) phases were found in the products under the tested thermal conditions.The results also indicate that kaolinite and mullite precursors exhibit different incorporation behavior,and ZnAl2O4 and Zn2SiO4 were found to be competitive as the Zn-hosting phases in the system.A prolonged leaching test was used to evaluate the leachability of potential product phases in the system.The concentrations of zinc in ZnO and Zn2SiO4 leachates were about two orders of magnitude higher than that in ZnAl2O4 leachate,indicating the preference of forming ZnAl2O4 for zinc stabilization.Furthermore,the aluminum-rich sludge generated from waterworks could be beneficially used as a material resource to stabilize zinc in this study.The X-ray diffraction(XRD) pattern collected from the 1150 ℃ and 3-h sintered sample shows the suc-cess of incorporating zinc into the ZnAl2O4 spinel structure with waterworks sludge precursor.The formation of ZnAl2O4 indicates a strong potential for employing aluminum-and silicon-based materials to thermally immobilize zinc and achieve the beneficial use of metal-laden MSWI ash.     

Optimizing Water Washing Process for Sunflower Heads before Pectin Extraction

Most pigment in sunflower heads is water soluble, but is strongly associated with extractable pectin. Washing sunflower heads before pectin extraction is necessary to remove pigment and improve pectin quality. An undesirable side effect is loss of water-soluble pectin. Response Surface Methodology (RSM) was applied to determine effects of variables and to optimize washing conditions for minimum pectin loss with maximum pigment removal. Benchscale washing experiments were carried out at 70-80°C for 10-30 min at water/solid ratios (v/w) of 20:1 to 40: 1, respectively. Both removal of water-soluble pigments and loss of pectin from sunflower tissue increased with increasing temperature, washing time, and water/solid ratio. Optimum conditions were 74.8°C for 25 min at a 25:1 water/solid ratio. This resulted in removal of 56.47% of the pigment, but loss of 2.90% of the pectin, which is practicable for the sunflower pectin industry.     

STABILIZATION OF AUSTENITE IN AN IRON-NICKEL-MANGANESE ALLOY

<正> 关于奥氏体的稳定化问题,早巳被人注意,后来又有许多人作了不少的研究,可是到现在还沒有得到一个统一的理论.由于许多细微的条件不能严格地加以控制,甚至试验的重复性都不太好,这也充分说明了奥氏体稳定化的复杂性.衡量奥氏体稳定化的标准普通有两个:一个是在固定条件下当马氏体转变完毕后衡量残留奥氏体的量;另一个是经过稳定化后测定马氏体继续转变温度的降低.在本     

A STUDY ON Fe-Mn-Al AUSTENITIC STEELS

配制了30个不同成分的鋼种,对Fe-Mn-Al系奥氏体鋼,进行了成分、組織結构、性能方面的研究。在研究的成分范围內,找出了奥氏体区与成分的經驗关系;观察了成分及組織結构对高低溫瞬时力学性能、持久强度、时效性能、抗氧化性能等的影响;得到了在650℃持久强度相当于257T的实驗鋼种,并初步确定了在Fe-Mn-Al系中发展出耐热鋼种的最可能成分范围。指出了在实驗鋼种A2的基础上,发展出无磁钢及低溫鋼的可能性。     

On the weighting factors of the quadratic criterion in optimal control

By the introduction of the time integral of the output variable of a second-order system, the optimal feedback control law with respect to the quadratic performance criterion gives the conventional proportional-integral-derivative (PID) control. Some comparisons between the weighting factors of the quadratic criterion and the parameters of the PID controller are given. The values of the weighting factors corresponding to the classical methods of Cohen-Coon and Ziegler-Nichols are calculated ; negative values of the weighting factors are obtained.     

COMBINED LAMINAR FREE AND FORCED CONVECTION FROM A VERTICAL PLATE TO POWER LAW FLUIDS

The boundary layer heat transfer for the steady two-dimensional incompressible combined laminar free and forced convection from a vertically static or moving plate to a power-law non-Newtonian fluid is analyzed by local similarity method. The effects of the flow index, buoyancy parameter, modified Prandtl number and streamwise distance on the heat transfer rate are discussed for the prescribed surface temperature and prescribed wall heat flux cases.     

小区、社群参与规划设计绿点——台北市罗斯福路绿生活轴线

台北市地狭人稠,经济发展之余越来越注重提升生活环境质量,除了都市计划的法定公园绿地外,小区居民渴望步行可及、生态永续的小区开放空间(community open space).参与式规划设计是了解使用者需求的一个重要设计方法,预先规划未来经营管理的共同维护单位与办法则是另一个能否让开放空间有效利用的关键.自2009年起,罗斯福路绿生活轴线实现了一个与非政府组织(NGO)、小区居民共同规划设计的过程,并透过小区、社群、NGO组织的认养与维护,让这些绿点充分融人当地生活.     

Optimal control of deterministic systems described by integrodifferential equations

The synthesis of an optimal control function for deterministic systems described by integrodifferential equations is investigated. By using the elegant operational properties of shifted Chebyshev polynomials, a direct computational algorithm for evaluating the optimal control and trajectory of deterministic systems is developed. An example is given to illustrate the utility of this method, and other orthogonal functions are also shown for comparison.