共混合金力学性能的研究 Ⅲ.CPP对PVC共混体系力学性能的影响

将ＰＰ氯化后作为ＰＶＣ共混体系的刚性体分散相，旨在改善高分子合金的相容性，ＤＳＣ实验表明，ＣＰＰ（氯化聚丙烯）与ＰＶＣ的相容性比ＰＶＣ与ＰＰ的好。在用弹性体增韧的ＰＶＣ／ＣＰＥ和ＰＶＣ／ＡＢＳ共混体系中加入刚性体ＣＰＰ后，随着ＣＰＥ、ＡＢＳ用量的增加，共混合金的冲击强度增加，并且由刚性的ＣＰＰ的加入所产生的冲击强度最大值的幅度也有所提高，其趋势是ＣＰＥ、ＡＢＳ用量越多，共混合金冲击强度值达到最大值时所需ＣＰＰ的量越多，增加的幅度也越大。ＣＰＰ对共混合金的拉伸屈服强度和断裂伸长率的影响比较小。     

CPP/MAH接枝共聚物合成及粘接性能研究

用马来酸酐 (MAH)对氯化聚丙烯 (CPP)进行接枝共聚 ,通过 1R分析证明马来酸酐与氯化聚丙烯发生了接枝共聚反应 ,考察了不同条件下制得的CPP/MAH接枝共聚物胶粘剂对聚烯烃材料的粘接性能 ,结果表明CPP/MAH共聚物胶粘剂对聚烯烃材料具有较好的粘接性能。     

中位-四[二-(3,4-羧甲氧基)苯基]卟啉及其结合Re=O的初步研究

用密度泛函理论的B3LYP法,将中位-四[二-(3,4-羧甲氧基)苯基]卟啉及结合Re=O分子的几何构型优化,初步理论研究其前沿轨道和能量等。证明,与单独的卟吩环相比,T_(3,4)CPP的卟吩环平面性良好,环上的结构参数变化很小;Re=O与T_(3,4)CPP卟吩环的结合能明显大于与T_(3,4)CPP侧链羧基的结合能,且前者所形成配合物的稳定性显然高于后者,说明T_(3,4)CPP与~(188)Re=O结合的位点应在卟吩环上,而不在侧链羧基上。T_(3,4)CPP卟吩环结合Re=O而形成配合物的结构参数,与Vicente等Zn-卟啉衍生物的测定值相近。在卟吩环上配位时,T_(3,4)CPP卟吩环上的电荷重新分布,卟吩环碳原子的电子向4个氮原子转移:配位后,卟吩环的几何构型略收缩(0.14 A-0.19 A)和马鞍形扭转(5.7°)。     

Impairment in long-term retention but not short-term performance on a water maze reversal task following hippocampal or mediodorsal striatal n-methyl-d-aspartate receptor blockade.

Male Long-Evans rats were injected with 32 ng/μl of the N-methyl-D-aspartate (NMDA) receptor antagonist 3-(2-carboxypiperazin-4-yl) propyl-1-phosphonic acid (CPP) or vehicle and trained to locate a hidden platform in a different location (reversal training) than used on the initial 4 days of training. Rats treated with vehicle or CPP into the dorsal hippocampus, basolateral amygdala, or mediodorsal striatum had similar latencies to locate the platform on the reversal day. Rats infused with CPP into the dorsal hippocampus or mediodorsal striatum failed to search preferentially in the novel location during a 24-hr, drug-free retention test, whereas all other groups searched preferentially in this location. Therefore, blocking dorsal hippocampal or mediodorsal striatal NMDA receptors selectively blocked long-term spatial retention without producing short-term performance deficits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Entropy maximisation and open queueing networks with priorities and blocking

A review is carried out on the characterisation and algorithmic implementation of an extended product-form approximation, based on the principle of maximum entropy (ME), for a wide class of arbitrary finite capacity open queueing network models (QNMs) with service and space priorities. A single server finite capacity GE/GE/1/N queue with R (R>1) distinct priority classes, compound Poisson arrival processes (CPPs) with geometrically distributed batches and generalised exponential (GE) service times is analysed via entropy maximisation, subject to suitable GE-type queueing theoretic constraints, under preemptive resume (PR) and head-of-line (HOL) scheduling rules combined with complete buffer sharing (CBS) and partial buffer sharing (PBS) management schemes stipulating a sequence of buffer thresholds {N=(N₁,…,N_R),0<N_i≤N_i−1,i=2,…,R}. The GE/GE/1/N queue is utilised, in conjunction with GE-type first two moment flow approximation formulae, as a cost-effective building block towards the establishment of a generic ME queue-by-queue decomposition algorithm for arbitrary open QNMs with space and service priorities under repetitive service blocking with random destination (RS-RD). Typical numerical results are included to illustrate the credibility of the ME algorithm against simulation for various network topologies and define experimentally pessimistic GE-type performance bounds. Remarks on the extensions of the ME algorithm to other types of blocking mechanisms, such as repetitive service blocking with fixed destination (RS-FD) and blocking-after-service (BAS), are included.     

CPP裂解气脱氧净化工业实验

50万t/a催化热裂解(CPP)制乙烯装置产生的裂解气中氧气含量较大,其会形成氧自由基并会引起重二烯烃的聚合反应而堵塞设备,同时裂解气中的氧气含量较高会影响聚合级乙烯和丙烯的产品质量。另外,氧加氢后生成水,水对后续的深冷工序有很大影响。某公司提供的脱氧脱氮催化剂,实际运行中结焦严重,再生频繁,最终被切除。后对裂解气除杂工艺进行更换,并与大连凯特利催化工程技术有限公司开展脱氧催化剂实验研究。目前氧含量由5×10-6降至1×10-6以下,达到预想除氧效果,具备实际工业应用条件。     

微氧条件下培养降解五氯酚的好氧颗粒污泥

在微好氧条件下(溶解氧浓度为0.2～0.7 mg/L)对降解五氯酚(PCP)的好氧颗粒污泥培养进行了研究.以厌氧颗粒污泥为接种污泥,采用反应器体外曝气的间歇工艺进行培养,考察了颗粒化过程中污泥外观、SVI、VSS/TSS、粒径以及PN/PS的变化.同时考察了对PCP、AOX和CODCr降解能力的变化.     

调距桨梢涡精细流场的数值模拟

为验证湍流粘度取为mk/的修正剪切应力输运(SST)湍流模型在螺旋桨梢涡精细流场粘性模拟中的适用性,对驱逐舰母型桨DTMB5168调距桨的梢涡流动进行了模拟与校验。结果显示:0.9R以上径向区域周向平均的轴向、周向和径向速度分量均与试验值吻合很好,但0.9R以下区域的径向速度分量存在一定偏差;0.7R和0.92R处沿周向变化的三个速度分量变化形态均与试验值一致,故可由此来确定梢涡涡核区,但周向和径向速度分量峰值比试验值略小;轴向0.3R距离内梢涡涡核运动轨迹的模拟结果与试验值吻合较好。由此证明了修正的SST湍流模型在螺旋桨梢涡流动模拟中的适用性,还表明由叶梢区的径向、周向和轴向方向以及桨叶近壁面法向、叶截面弦长方向和尾流轴向方向的网格节点密度来局部控制叶梢区流动的模拟效果的可行性。     

Coverage path planning for UAVs based on enhanced exact cellular decomposition method

In this paper, an enhanced exact cellular decomposition method to plan the coverage path of UAVs in a polygon area is proposed. To be more specific, the contributions of the paper are: firstly, the turning motion of UAVs is shown to be less efficient from the viewpoints of route length, duration and energy. Secondly, the problem of coverage Path Planning (CPP) in a convex polygon area is transformed to width calculation of the convex polygon, and a novel algorithm to calculate the widths of convex polygons with time complexity of O(n) is developed. The path of the least number of turns for an UAV based on the widths of convex polygons is devised. Thirdly, a convex decomposition algorithm for minimum width sum based on the greedy recursive method which revolves around decomposing the concave area into convex subregions is developed. It is proved that the algorithm is a polynomial time algorithm. To avoid unnecessary back and forth motion, some entirely adjacent subregions are combined. Finally, comparing different weights of two joint-points, a subregion connection algorithm based on minimum traversal of weighted undirected graph is proposed to connect the coverage paths of the subregions. Simulation results show that the proposed method is feasible and effective.     

The effect of heat sealing temperature on the properties of OPP/CPP heat seal. I. Mechanical properties

The effect of heat sealing temperature on the mechanical properties and morphology of OPP/CPP laminate films was investigated. The laminated films were placed in an impulse type heat sealing machine with both CPP sides facing each other. The temperatures investigated ranged from 100 to 250°C. T‐peel and tensile tests in combination with SEM were used to characterize the heat seals. A minimum seal initiation temperature of 120°C was identified for OPP/CPP laminate heat sealing. Peel strength increased sharply from zero at 110°C to maximum at 120°C, after which a gradual decrease was observed. Tensile strength initially increased until 120°C, after which it gradually decreased until 170°C and assumed a constant value beyond that. The initial rise has been associated to cold crystallization, while the reduction between 120°C and 170°C was due to relaxation in molecular orientation. Beyond 170°C, all the orientation in the laminate has been lost so orientation effects are nullified. Morphological studies with SEM revealed that seals were partially formed at lower temperatures, while the laminates were totally fused together at high temperatures, with intermediate temperatures showing properties that lie in between. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 753–760, 2005