基于液化天然气冷量的液体空分新流程

分析了空分装置中应用液化天然气(LNG)冷量的优势.从流程设计和现有流程改造的角度,分别提出了采用LNG冷量冷却循环氮气的液体空分装置的新方案,并采用Aspen Plus软件对其进行模拟计算.研究表明:与传统流程相比较,新方案采用LNG作为冷源冷却循环氮气后,可以代替氟利昂制冷机以及氮透平膨胀机组,取消了氮气外循环,系统得到简化,所需循环氮气量明显减少;系统最高运行压力由传统流程的4.2~5.0 MPa降低到2.3~2.6 MPa;液态产品的单位能耗从1.05~1.25 kW.h/kg降低到0.317~0.384 kW.h/kg.     

论中部崛起进程中的江西教育发展战略

新时期,江西提出并实施了要在中部地区快速崛起的发展战略。在这一过程中,江西教育发展面临着极好的机遇,同时,也遭遇到了八个方面的挑战。于是,江西省委省政府提出了江西教育发展的总体要求。江西广大教育行政部门和教育工作者只要不断沿着中央指出的方向,落实省委省政府的部署,埋头苦干、扎实工作,就一定能为建设创新创业江西、绿色生态江西、和谐平安江西,为江西在中部地区的早日崛起提供有力的人才支持、知识基础和文化贡献,就一定能铸造出江西教育事业新的辉煌。     

Bernoulli方程的演示设计

Bernoulli方程是流体力学的一个基本方程。本将介绍几种简单、有趣而又十分有效的Bernoulli方程演示设计。     

Fenton 试剂处理2,4-D废水研究

利用Fenton试剂(Fe2+/H2O2)处理含有除草剂2,4-二氯苯氧乙酸(2,4-D)的模拟废水.结果显示,Fenton试剂对2,4-D有很好的去除效果.Fe2+和H2O2的摩尔比为1:20,在H2O2为1/2Qth理论投加量的条件下处理30mtn,2,4-D去除率达到80.0%.考察了Fe2+投加量、Fe2+和H2O2投加比、2,4-D初始浓度和pH等因素对2,4-D降解的影响.通过GC-MS和HPLC检测到反应中间产物有2,4-二氯苯酚、邻氯苯酚和对氯苯酚,氯离子在这些中间产物上释放.通过离子色谱检测到进一步氧化的产物还有小分子酸,如乙醇酸、乙醛酸、顺丁烯二酸,提出了Fenton降解2,4 -D的可能途径.     

Influence of Turbid Medium Parameters on Back Scattered Intensity and Pulsewidth of Picosecond Pulse

In this paper, we simulate a practical in vivo technique in which is produced influence of turbid medium parameters on backscattered intensity and pulsewidth of picosecond for turbid tissue surface of a semiinfinite medium by a small narrow linewidth laser beams. It is shown that the interaction of the ultra short pulse and the turbid tissue is very used as researching the optical parameters of the turbid medium.     

如何在教学中开拓学生的发散性思维

从初中进入高一级学校，物理跨了一个高台阶，常使学生感到束手无策，“一听就懂，一做就错．”是学生经常向老师谈的体会．为什么会产生这一情况呢?原因是他们的习惯思维在作怪，使他们在看问题时总有盲点，怎样才能开拓学生的发散性思维?使他们的思维在今后的学习中不为所“框”、不为所“漏”．我认为应从以下方面着手．     

Periodic solutions of a second order forced sublinear differential equation with delay

In this paper, existence criteria are established for the existence of periodic solutions of a second order sublinear differential equation with delay and forcing function. Our method is based on careful a priori estimation and continuation theorems, and our sublinear condition is an improvement of the boundedness condition in some recent results.     

Preparation of well-aligned carbon nanotubes by pyrolysis of phenolic resin in anodic alumina pores

Well-aligned carbon nanotubes (CNTs) of high quality were synthesized by pyrolysis of phenolic resin at 800 °C in anodic alumina oxide (AAO) pores under argon protection. The innocuous source materials and safe operational conditions permit this method to synthesize well-aligned CNTs in large-scale and low cost. The formation mechanism of the synthesized CNTs is also proposed in this work by a series of visual sketches and is proved with obvious evidence. Firstly, phenolic resin nanotubes form in the template pores through the evaporation of solvent. Heat treatment then transfers these tubes into CNTs.     

BOUNDEDNESS OF VECTOR-VALUED CALDERN-ZYGMUND OPERATORS ON HERZ SPACES WITH NON-DOUBLING MEASURES

In the paper we obtain vector-valued inequalities for Calder6n-Zygmund operator, simply CZO on Herz space and weak Herz space. In particular.we obtain vector-valued inequalities for CZO on Lq(Rd, |x|αdμ) space, with 1< q <∞, -n <α< n(q -1), and on L1,∞(Rd,|x|αdμ) space, with -n <α< 0.     

Formation of β‐iPP in isotactic polypropylene/ethylene–propylene rubber blends: Effects of preparation method,composition, and thermal condition

The effects of preparation method, composition, and thermal condition on formation of β‐iPP in isotactic polypropylene/ethylene–propylene rubber (iPP/EPR) blends were studied using modulated differential scanning calorimeter (MDSC), wide angle X‐ray diffraction (WAXD), and phase contrast microscopy (PCM). It was found that the α‐iPP and β‐iPP can simultaneity form in the melt‐blended samples, whereas only α‐iPP exists in the solution‐blended samples. The results show that the formation of β‐iPP in the melt‐blended samples is related to the crystallization temperature and the β‐iPP generally diminishes and finally vanishes when the crystallization temperature moves far from 125 °C. The phenomena that the lower critical temperature of β‐iPP in iPP/EPR obviously increases to 114 °C and the upper critical temperature decreases to 134 °C indicate the narrowing of temperature interval, facilitating the formation of β‐iPP in iPP/EPR. Furthermore, it was found that the amount of β‐iPP in melt‐blended iPP/EPR samples is dependent on the composition and the maximum amount of β‐iPP formed when the composition of iPP/EPR blends is 85:15 in weight. The results through examining the effect of annealing for iPP/EPR samples at melt state indicate that this annealing may eliminate the susceptibility to β‐crystallization of iPP. However, only α‐iPP can be observed in solution‐blended samples subjected to annealing for different time. The PCM images demonstrate that an obvious phase‐separation happens in both melt‐blended and solution‐blended iPP/EPR samples, implying that compared with the disperse degree of EPR in iPP, the preparation method plays a dominant role in formation of β‐iPP. It is suggested that the origin of formation of β‐iPP results from the thermomechanical history of the EPR component in iPP/EPR. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1704–1712, 2007