300MW燃油直流炉机组的给水联合处理

本文介绍了给水联合处理的原理及其优点以及在望亭电厂的1台300MW亚临界燃油直流炉上进行这项处理的工业性试验的过程、效果及存在问题。最后作者对给水联合处理能否取得成效的关键提出了意见。     

异戊二烯及其光氧化产物的傅里叶变换红外光谱研究

利用傅里叶变换红外吸收光谱,测量得到了异戊二烯单体分子的光谱信息,采用Gaussion03程序,通过密度泛函方法计算得到异戊二烯的红外光谱,理论结果与实验结果符合较好.利用自制的烟雾腔模拟研究.OH自由基启动的异戊二烯光氧化过程,使用傅里叶变换红外光谱仪,测定光氧化产物的分子官能团,定性分析产物组分.结果表明产物中含有羰基化合物、C-O键化合物、醛、酮、羧酸及硝酸类有机化合物.     

Bacterial Growth and Volatile Compounds in Yoghurt-Type Products from Soymilk Containing Bifidobacterium ssp

The growth of bacteria normally used to produce yoghurt was compared in soymilk and cow milk. Whether or not Bifidobacterium ssp. was present, fermented soymilks [soyoghurt (S), soyoghurt + bifi-dobacteria (SB)] were less acidic than fermented cow milks [yoghurt (Y), yoghurt + bifidobacteria (YB)]. When bifidobacteria were present (in SB), streptococci were more numerous than lactobacilli. Bifidobacteria in YB stimulated maximal growth of both yoghurt bacteria. In comparison to nonfermented milks, acetaldehyde and diacetyl increased in all cultures. Ethanol increased only in S/SB and acetone was detected only in Y/YB. Quantities of volatile products in Y/'YB were slightly lower than those in Y/S. In all cultures, n-hexanal was almost totally absent.     

Non‐Volatile Polymer Electroluminescence Programmable with Ferroelectric Field‐Induced Charge Injection Gate

Electroluminescence (EL) of organic and polymeric fluorescent materials programmable in the luminance is extremely useful as a non‐volatile EL memory with the great potential in the variety of emerging information storage applications for imaging and motion sensors. In this work, a novel non‐volatile EL memory in which arbitrarily chosen EL states are programmed and erased repetitively with long EL retention is demonstrated. The memory is based on utilizing the built‐in electric field arising from the remnant polarization of a ferroelectric polymer which in turn controls the carrier injection of an EL device. A device with vertically stacked components of a transparent bottom electrode/a ferroelectric polymer/a hole injection layer/a light emitting layer/a top electrode successfully emits light upon alternating current (AC) operation. Interestingly, the device exhibits two distinctive non‐volatile EL intensities at constant reading AC voltage, depending upon the programmed direct current (DC) voltage on the ferroelectric layer. DC programmed and AC read EL memories are also realized with different EL colors of red, green and blue. Furthermore, more than four distinguishable EL states are precisely addressed upon the programmed voltage input each of which shows excellent EL retention and multiple cycle endurance of more than 10⁵ s and 10² cycles, respectively.     

Emerging Wearable Sensors for Plant Health Monitoring

Emerging plant diseases, caused by pathogens, pests, and climate change, are critical threats to not only the natural ecosystem but also human life. To mitigate crop loss due to various biotic and abiotic stresses, new sensor technologies to monitor plant health, predict, and track plant diseases in real time are desired. Wearable electronics have recently been developed for human health monitoring. However, the application of wearable electronics to agriculture and plant science is in its infancy. Wearable technologies mean that the sensors will be directly placed on the surfaces of plant organs such as leaves and stems. The sensors are designed to detect the status of plant health by profiling various trait biomarkers and microenvironmental parameters, transducing bio-signals to electric readout for data analytics. In this perspective, the recent progress in wearable plant sensors is summarized and they are categorized by the functionality, namely plant growth sensors, physiology, and microclimate sensors, chemical sensors, and multifunctional sensors. The design and mechanism of each type of wearable sensors are discussed and their applications to address the current challenges of precision agriculture are highlighted. Finally, challenges and perspectives for the future development of wearable plant sensors are presented.     

有机载体挥发特性对PTC陶瓷铝电极性能的影响

为了制备出满足铝电极性能要求的电极浆料,采用两种具有不同挥发特性的有机载体烧渗PTC铝电极,通过XRD和SEM研究了烧渗后铝电极的物相和微观形貌对电极性能的影响。结果表明:采用阶梯式挥发的有机载体制备的铝电极浆料,烧渗后的电极结构致密,假电阻小,|RAl-RIn-Ga|/RIn-Ga约为0.3%;抗老化性能优良,沸水中老化24h后,电阻变化率不超过2.3%,经400V交流电压冲击500h后,电阻变化率不超过1.0%。     

质子转移反应飞行时间质谱的建立与性能研究

介绍了自主研制的质子转移反应飞行时间质谱的基本结构和性能。首先对数据采集卡甄别离子脉冲的阈值电压进行了优化,结果表明当阈值电压为0.33V时,H316O+(m/z 19)与H318O+(m/z 21)的离子计数比约500:1;然后考察了水团簇离子H3O+(H2O)n的分布与漂移管约化电场的关系,结果表明,当E/N为139 Td时,团簇离子得到很好地抑制,质谱观察到的离子主要是H3O+,其纯度可达99%以上;随后考察了质谱的分辨率,结果表明在m/z124处,分辨率最好,达到2653; 采用不同浓度的乙醇标样对仪器的线性范围和检测限性能进行了测试,结果表明该仪器的线性动态范围可达三个数量级,检测限可达3.8 ppb; 最后用该质谱仪检测了实验室空气,得到了实验室空气的质谱图。自主研制的质子转移反应飞行时间质谱可实现对痕量挥发性有机物的实时在线测量,在环境、食品、医学等领域具有重要应用价值。     

Nano‐Domain Pinning in Ferroelastic‐Ferroelectrics by Extended Structural Defects

Most ferroelectrics are also ferroelastics (hysteretic stress‐strain relationship and response to mechanical stresses). The interactions between ferroelastic twin walls and ferroelectric domain walls are complex and only partly understood, hindering the technological potential of these materials. Here we study via atomic force microscopy the pinning of 180‐degree ferroelectric domain walls in lead zirconate titanate (PZT). Our observations satisfy all three categories of ferroelectric‐ferroelastic domain interaction proposed by Bornarel, Lajzerowicz, and Legrand.     

Mimicking Neuroplasticity in a Hybrid Biopolymer Transistor by Dual Modes Modulation

Neuromorphic computing systems that are capable of parallel information storage and processing with high area and energy efficiencies, offer important opportunities for future storage systems and in‐memory computing. Here, it is shown that a carbon dots/silk protein (CDs/silk) blend can be used as a light‐tunable charge trapping medium to fabricate an electro‐photoactive transistor synapse. The synaptic device can be optically operated in volatile or nonvolatile modes, ensuring concomitant short‐term and long‐term neuroplasticity. The synaptic‐like behaviors are attributed to the photogating effect induced by trapped photogenerated electrons in the hybrid CDs/silk film which is confirmed with atomic force microscopy based electrical techniques. In addition, system‐level pattern recognition capability of the synaptic device is evaluated by a single‐layer perceptron model. The remote optical operation of neuromorphic architecture provides promising building blocks to complete bioinspired photonic computing paradigms.     

Femtojoule-Power-Consuming Synaptic Memtransistor Based on Mott Transition of Multiphasic Vanadium Oxides

To realize the potential of Mott transition of multiphasic vanadium oxides (VO_x) for memory applications, the development of VO_x memtransistors on SiO₂ wafer is introduced. Through electrical characterizations, the volatile memory behaviors of the VO_x memtransistors are observed in both two- and three-terminal measurements. Their capacitive memory and resistive switching mechanisms are strongly related to the mixed VO_x/SiO₂ interface (called VSiO_x). VSiO_x supports the Mott transition in VO_x at low bias voltages (<0.5 V), leading to the low power consumption of the memtransistor. Moreover, the fast switching time (≈35 ns) and tunable memory retention with the synaptic functions (potentiation and depression) of the memtransistors (by using the gate and drain biases) are demonstrated. Overall, the findings open up major opportunities for constructing ultrafast and femto-joule power-consuming neuromorphic devices.