Study of the spangle size of 55％ Al-Zn-Si steel

The spangle size of the 55% Al-Zn-Si steel is affected by the composition of the zinc pot,the cooling capacity after plating,and the substrate. According to previous studies,the size of spangles can be reduced by increasing the cooling ability after plating,and by adding Ti in the zinc pot. However,these two methods cannot reduce the spangle size smaller than 1. 5 mm. Therefore,in this study,we have focused on the influence of substrates on the formation of spangles of 55% Al-Zn-Si steel by comparing and analyzing substrates with different surface roughness,composition,morphology,crystal orientation,and alloy layers.     

基于无线传感器网络的油井远程监控系统设计

现有的油井抽油机远程监控系统建设费用昂贵且存在通信盲区的问题,针对这一状况设计了一种基于无线传感器网络的油井监控系统.采用无线微处理器JN51 39构建基于ZigBee协议的无线监测网络;结合GPRS模块MC55构建网关节点实现数据汇聚和GPRS通信方式的远程数据转发.该系统工作性能稳定,将其应用在油田可实现油田生产管理的信息化和自动化.     

热浸镀55%Al-Zn后钢的拉伸性能和耐蚀性能研究

研究了热浸镀55%Al-Zn合金镀层钢的室温拉伸性能和耐蚀性能。结果表明：Q235钢板经热浸镀55%Al-Zn合金后的室温屈服强度和抗拉强度均高于Q235钢，而伸长率没有降低。经SEM观察，55%Al-Zn合金镀层钢的拉伸断口由钢基体的韧窝断口和Fe-Al-Zn-Si合金层的穿晶解理断口组成。腐蚀试验结果显示：热浸镀55%Al-Zn合金后钢的耐蚀性在盐雾中是镀锌钢的6倍，在盐水中是镀锌钢的3倍，并同样具有镀锌层对钢基体的电化学保护能力。     

SPION‐Decorated Exosome Delivered BAY55‐9837 Targeting the Pancreas through Magnetism to Improve the Blood GLC Response

BAY55‐9837, a potential therapeutic peptide in the treatment of type 2 diabetes mellitus (T2DM), is capable of inducing glucose (GLC)‐dependent insulin secretion. However, the therapeutic benefit of BAY55‐9837 is limited by its short half‐life, lack of targeting ability, and poor blood GLC response. How to improve the blood GLC response of BAY55‐9837 is an existing problem that needs to be solved. In this study, a method for preparing BAY55‐9837‐loaded exosomes coupled with superparamagnetic iron oxide nanoparticle (SPIONs) with pancreas islet targeting activity and an enhanced blood GLC response with the help of an external magnetic force (MF) is demonstrated. The plasma half‐life of BAY55‐9837 loaded in exosome‐SPION is 27‐fold longer than that of BAY55‐9837. The active targeting property of SIPONs enables BAY‐exosomes to gain a favorable targeting property, which improves the BAY55‐9837 blood GLC response capacity with the help of an external MF. In vivo studies show that BAY‐loaded exosome‐based vehicle delivery enhances pancreas islet targeting under an external MF and markedly increases insulin secretion, thereby leading to the alleviation of hyperglycemia. The chronic administration of BAY‐exosome‐SPION/MF significantly improves glycosylated hemoglobin and lipid profiles. BAY‐exosome‐SPION/MF maybe a promising candidate for a peptide drug carrier for T2DM with a better blood GLC response.     

Quantifying the impact of agricultural technology usage on intra-household time allocation: Empirical evidence from rice farmers in Ghana

The use of improved agricultural technologies that lead to improved productivity, income and food security, could also destabilize intra-household time allocation. Using primary data from 917 rice farmers in Ashanti and Upper East Regions of Ghana, this paper employs a two-stage Bourguignon, Fournier, and Gurgand (BFG) selection bias correction model to quantify the impact of improved rice production technologies on intra-household time allocation. The empirical results indicate that farmers who take up improved rice technologies (fertilizer and improved rice seed) tend to increase labour input in farm work by 13.93 h per week. This has implications for the amount of time available for domestic work and leisure, especially for women in typical rice farming household. The design and development of technological innovations in the agricultural sector should take serious account of the domestic workload of women in farming communities to improve intensity and sustainability of use for both men and women.     

A Black-Box Iterative Solver Based on a Two-Level Schwarz Method

We propose a black-box parallel iterative method suitable for solving both elliptic and certain non-elliptic problems discretized on unstructured meshes. The method is analyzed in the case of the second order elliptic problems discretized on quasiuniform P1 and Q1 finite element meshes. The numerical experiments confirm the validity of the proved convegence estimate and show that the method can successfully be used for more difficult problems (e.g. plates, shells and Helmholtz equation in high-frequency domain.) Received: July 28, 1997; revised June 20, 1999     

Energy Optimization of Algebraic Multigrid Bases

We propose a fast iterative method to optimize coarse basis functions in algebraic multigrid by minimizing the sum of their energies, subject to the condition that linear combinations of the basis functions equal to given zero energy modes, and subject to restrictions on the supports of the coarse basis functions. For a particular selection of the supports, the first iteration gives exactly the same basis functions as our earlier method using smoothed aggregation. The convergence rate of the minimization algorithm is bounded independently of the mesh size under usual assumptions on finite elements. The construction is presented for scalar problems as well as for linear elasticity. Computational results on difficult industrial problems demonstrate that the use of energy minimal basis functions improves algebraic multigrid performance and yields a more robust multigrid algorithm than smoothed aggregation. Received: March 9, 1998; revised January 25, 1999     

缓冷和快冷条件下Ti—55合金中稀土相的凝固特征

Ｔｉ５５ 高温钛合金在缓冷（１０００ ｋｇ 铸锭冒口） 条件下, 正常凝固区中稀土相呈弥散分布状态,初始补缩区中稀土相聚集成团, 正常补缩区中稀土相颗粒沿平行于凝固界面方向规则排列; 在快冷（ 锤砧薄片） 条件下, 稀土相除弥散分布在合金中外, 出现稀土相颗粒排列成行的现象。两种凝固条件下均出现颗粒规则排列现象的原因是凝固界面的平面长大。     

Targeting Oxidative Stress: Novel Coumarin-Based Inverse Agonists of GPR55

Oxidative stress is associated with different neurological and psychiatric diseases. Therefore, development of new pharmaceuticals targeting oxidative dysregulation might be a promising approach to treat these diseases. The G-protein coupled receptor 55 (GPR55) is broadly expressed in central nervous tissues and cells and is involved in the regulation of inflammatory and oxidative cell homeostasis. We have recently shown that coumarin-based compounds enfold inverse agonistic activities at GPR55 resulting in the inhibition of prostaglandin E₂. However, the antioxidative effects mediated by GPR55 were not evaluated yet. Therefore, we investigated the antioxidative effects of two novel synthesized coumarin-based compounds, KIT C and KIT H, in primary mouse microglial and human neuronal SK-N-SK cells. KIT C and KIT H show antioxidative properties in SK-N-SH cells as well as in primary microglia. In GPR55-knockout SK-N-SH cells, the antioxidative effects are abolished, suggesting a GPR55-dependent antioxidative mechanism. Since inverse agonistic GPR55 activation in the brain seems to be associated with decreased oxidative stress, KIT C and KIT H possibly act as inverse agonists of GPR55 eliciting promising therapeutic options for oxidative stress related diseases.     

高清晰度电视样机控制子系统的实现

本文提出了基于微处理器AT89C55的国家高清晰度电视样机控制子系统的总体设计方案和软硬件实现方法。目前，该控制系统己顺利完成，并参与北京、上海两地的功能样机测试。