煤与生物油的成浆性能研究

利用不同煤种的煤和生物油制备了不同浓度的生物油煤浆,考察了生物油煤浆的成浆浓度、表观黏度、流变特性和稳定性。结果表明,生物油煤浆是具有一定屈服应力的非牛顿流体,其流变特性可用宾汉姆方程来描述;生物油煤浆的屈服应力和表观黏度都随着固体浓度的增加而增大;随着剪切速率的增加,生物油煤浆的表观黏度减小;四种煤中,无烟煤的成浆浓度最高,可达42%,其含碳量高达49%,相当于同种煤制成的74%的水煤浆含量。烟煤次之,褐煤最低;生物油与煤粉之间能够形成絮凝性的大分子网络结构,使得生物油煤浆存在屈服应力并能够保持良好的静态稳定性,4.0~5.0 d天没有软沉淀产生,数月没有硬沉淀产生。     

NEWS

构建最蛋近白,同质济阵大列学对化生学物系传田感阳器课、题蛋组白报质道组了学一、组种织基工于程蛋学白、质生微物阵电列子,器具件有等选的择发性展吸具附有、原重位要培的养作细用胞。     

阴离子型芘基探针用于水体中对硝基苯胺的荧光检测

本研究利用阴离子型芘衍生物8-羟基芘-1,3,6-三磺酸三钠盐(HPTS),建立了一种快速、可视化的对硝基苯胺(PNA)荧光检测方法.检测原理主要是基于PNA通过非共价作用而导致的HPTS的荧光淬灭.通过测量加入PNA后HPTS在512 nm处荧光强度的变化,可以实现PNA的荧光检测.本方法的线性范围为10~120μmol/L,检出限(3σ/s)为4.6μmol/L.对本方法的抗干扰性以及方法的实际应用性进行了考察.结果表明,本方法具有低成本、高灵敏度、高选择性、操作简便等优点.     

EFFECT OF HEAD SHAPE ON THE ADHESION CAPABILITY OF MUSHROOM-LIKE BIOLOGICAL ADHESIVE STRUCTURES

Theoretical studies have been extensively performed to reveal the mechanism of the biological adhesive structure with a flat head.However,most biological adhesive structures have a big head.Here we investigate the effect of the head shape on the adhesion capability of a mushroomlike adhesion structure based on a finite element model.We show that a mushroom-like head produces significant adhesion enhancement.We investigate also the effect of the elastic modulus of the adhesive structure on the adhesion.Our results are consistent with existing experimental results.     

Ultrasonic guided wave inspection with array sensors

Ultrasonic guided wave becomes one of promising tool for monitoring various types of structures such as large steel plates, vessels, and pipes in oil, chemical or nuclear industry, because guided waves have ability to travel wide range of the target structure in a single position. However, analysis of guided wave signals acquired from structure is difficult on account of low S/N ratio and its dispersive nature. To improve S/N ratio and overcome dispersion effect, focusing techniques for guided waves are needed. Thus, in this study, focusing techniques for guided waves were developed in order to improve long range inspection ability, and performance of the developed techniques was verified by experiments.     

A method for detecting target echo in reverberation based on fractional Fourier transform

A method for detecting the target echo in reverberation was proposed based on fractional Fourier transform theory when the transmitted signal is linear frequency modulation signal. The slow time-varying envelope of reverberation is computed to process reverberation to be stationary. The stationary reverberation is cut into blocks using a sliding window. A narrow-band filter is applied in FrFT domain for each block and the signal is recovered through inverse FrFT. Output of the system is the energy of the recovered signal. When the target echo is included in one of the blocks, the reverberation noise is reduced, and the output is the energy of the target echo. All the simulation and lake experiment results show that the detection performance of the present method is better than that of the matched filter.     

第三方检测市场入侵条件下乳品供应链网络均衡研究

构建包含生鲜乳供应商、第三方检测机构、乳品制造商以及需求市场的乳品供应链网络均衡模型，揭示第三方检测机构入侵下，生鲜乳检测技术革新投入水平变化对乳品供应链各层级均衡决策的影响。研究结果表明：第三方检测机构承担生鲜乳检测技术投入，有利于供应链检测质量水平的提升，行业风险规避能力加强，供应链整体获利增加，是实现乳品供应链治理的有益尝试；生鲜乳供应商应在质量控制上占据主导地位，通过价格传导机制，促使乳制品制造商分担部分检测费用；政府在第三方检测环境下扮演监管角色，通过补贴与惩罚举措提升第三方检测机构的公平性及公正性，并通过策略调整来推动第三方检测的市场化运作。