基于模糊建模的冷凝器污脏软测量

提出了一种基于模糊建模的冷凝器污脏软测量方法.该方法选取传热端差作为研究对象,应用模糊建模技术分离出冷凝器污脏对端差的影响.在模糊建模中,采用T_S模型描述变工况传热端差,研究了一种相似度判别法则以确定最优模型结构,并采用实数编码的遗传算法同时优化模型前、后件参数,从而获得了规则简化、精度较高的模糊模型.根据此方法,设计了试验系统,并进行了现场试验.试验结果表明:该方法能有效地在线监测冷凝器污脏,并在冷凝器出现堵管或空气漏入量较大时,取得比热阻法、传热系数法更可靠的测量结果.

冷凝器污脏测量仪的研究

提出了一种在线测量冷凝器污脏程度的新方法.该方法选取冷凝器压力作为研究对象,以模糊建模技术为基础有效地实现了冷凝器污脏、工况参数变化对冷凝器压力影响的分离,可较准确地在线监测冷凝器污脏.根据此方法,研制了以DSP为核心的测量仪,并在不同工况下进行了现场试验.试验结果表明:与热阻法及传热系数法相比,该测量仪能够取得更好的测量效果.

基于对角递归神经网络的冷凝器污脏测量

提出了一种在线测量冷凝器污脏的新方法。该方法选取传热端差作为研究对象,运用对角递归神经网络建立变工况端差模型,成功分离出冷凝器污脏对端差的影响,准确实现冷凝器污脏程度的在线监测。根据此方法,研制了以数字信号处理器为核心的测量装置,并进行了现场试验,试验结果证明:该方法有效、可行。

冷凝器污脏测量方法的研究

提出了一种在线测量冷凝器污脏程度的新方法。该方法选取传热端差作为研究对象 ,以神经网络建模技术为基础成功实现冷凝器污脏、工况参数变化对传热端差影响的分离 ,可较准确地实现冷凝器污脏的在线监测。在神经网络建模中 ,采用RBF神经网络描述变工况传热端差变化的非线性过程 ,研究了一种自适应训练算法动态调整网络结构与参数 ,从而获得了结构紧凑、精度较高的测量模型 ,便于实时应用。根据此方法 ,研制了以DSP为核心的测量仪 ,并在不同工况和堵管情况下进行了现场试验 ,试验结果证明了该方法的有效性。

凝汽器污脏程度在线监测仪的研制

提出了一种在线监测凝汽器污脏程度的新方法。该方法将传热端差作为研究对象,综合考虑各因素对端差的影响,运用神经网络建模技术成功地实现了凝汽器污脏、工况参数变化对端差影响的分离,可准确地在线监测凝汽器污脏程度。介绍了根据此方法研制的以DSP为核心的监测仪,并进行了现场试验,试验结果证明了该仪器的有效性。

冷凝器高压水自动清洗系统

针对冷凝器现有清洗方法的不足,研制了一种高压水自动清洗系统。该系统以PLC和工控PC为核心,可自动实现冷凝器冷却铜管的在线清洗,提高生产效率。为了确保清洗系统的合理、高效运行,提出了测量冷凝器污脏程度的新方法,深入研究了系统控制原理及其相关参数的设定,并对控制系统的软、硬件设计作了较详细的介绍。该系统已投入现场运行,运行结果表明该系统能够取得良好的清洗效果。

Mechanical behavior and deformation mechanism of ballast bed with various fouling materials

In order to study the interaction between various fouling particles and ballast,a multi-layer and multi-scale discrete element model(DEM)including the sleeper,ballast bed and the surface layer of subgrade was developed.Two typical fouling particles,the hard particles(sand)and soft ones(coal fines),are considered.A support stiffness test of the ballast bed under various fouling conditions was conducted to calibrate the microscopic parameters of the contact model.With the model,the influence of fouling particles on the mechanical behavior and deformation of the ballast bed was analyzed from macro and micro perspectives.The results show that the increase in the strength of the fouling particles enlarges the stiffness of the ballast bed.Hard particles increase the uniformity coefficient of the contact force bondγof ballast by 50.4%.Fouling particles increase the average stress in the subgrade,soft particles by 2 kPa and hard particles by 1 kPa.Hard particles can reduce the elasticity,plastic deformation and energy dissipation in the track structure.As the fouling particle changes from hard to soft,the proportion of the settlement in ballast bed increases to 40.5%and surface layer of swbgrade settlement decreases to 59.5%.Thus,the influence of fouling particles should be considered carefully in railway design and maintenance.

Arsenic exposure decreases rhythmic contractions of vascular tone through sodium transporters and K^+ channels

Arsenic-contaminated drinking water is a public health problem in countries such as Taiwan, Bangladesh, United States, Mexico, Argentina, and Chile. The chronic ingestion of arsenic-contaminated drinking water increases the risk for ischemic heart disease, cerebrovascular disease, and prevalence of hypertension. Although toxic arsenic effects are controversial, there is evidence that a high concentration of arsenic may induce hypertension through increase in vascular tone and resistance. Vascular tone is regulated by the rhythmic contractions of the blood vessels, generated by calcium oscillations in the cytosol of vascular smooth muscle cells. To regulate the cytosolic calcium oscillations, the membrane oscillator model involves the participation of Ca2+ channels, calcium-activated K+ channels, Na+/Ca2+exchange, plasma membrane Ca2+-ATPase, and the Na+/K+-ATPase. However, little is known about the role of K+ uptake by sodium transporters [Na+/K+-ATPase or Na+-K+-2Cl-(NKCC1)] on the rhythmic contractions.Vascular rhythmic contractions, or vasomotion are a local mechanism to regulate vascular resistance andblood flow. Since vascular rhythmic contractions of blood vessels are involved in modulating the vascular resistance, the blood flow, and the systemic pressure,we suggest a model explaining the participation of the sodium pump and NKCC1 co-transporter in low dose arsenic exposure effects on vasomotion and vascular dysfunction.

Introduction of T-DNA into Watermelon by Stigma Smeared Method and Its Molecular Marker Research

[Objective]The aim was to introduce T-DNA into watermelon for its molecular marker research.[Method]Based on the method of foreign DNA introduced to Arabidopsis thaliana via dipping flowers,the stigma smear was used to transfer T-DNA into watermelon and its molecular marker research was carried out.[Result]The ideal transformed species was ZXG01078 for the highest fruit setting rate and the most deviant seedlings.The best concentration of kanamycin for treating watermelon seeds was 500-700 mg/L with differences among the species.The best position was spire leaf or young leaf and the best concentration of kanamycin for treating the watermelon leaf was 4 000-8 000 mg/L with no significant difference among species.The steadily variation appearing of growing pointless and conjoined twin seedlings indicated that the normal growth had been interfered by foreign DNA in the progeny.[Conclusion]This study had provided basis for the further research on watermelon.

郭建强的散文

暗夜打扫完卫生,我们这群面孔污脏、汗流浃背、浑如鬼怪的家伙纷纷坐在车间窗前。有人打开长扇铁制窗户直接坐在窗台上,也有人干脆一屁股坐在冰凉、悬空的水泥板上。有经验的老工人则扣紧衣领,甚至都没脱下靴子。刚才,大伙儿苦干了一个多小时,连喘气撒尿的空当都没有。揭开槽盖板,表面温度达九百多度的电解质狂烈地散射出炽气。