循环流化床锅炉点火系统的数值模拟分析

循环流化床(CFB)锅炉点火系统主要以风道燃烧器为主。风道燃烧器在实际运行时,燃油着火和燃尽性能不是很理想,会出现火焰贴壁、壁面结焦等现象,因此对CFB锅炉点火系统进行数值模拟研究。针对内蒙古某电厂CFB锅炉风道燃烧器实际燃烧工况,选用非结构化有限元体积网格模型进行数值模拟。通过对点火系统的数值模拟和实测结果比较分析,验证了针对内蒙古某电厂CFB锅炉点火系统进行理论模拟所设置的物理模型和边界条件是符合实际的,理论模拟和实测结果的相对误差在10%范围内,结果较为理想。说明利用FLUENT软件对点火系统内温度场及压力场的情况进行模拟分析是可行的,对同类电厂具有一定的参考价值。     

基于CYME的配电网可靠性评估应用

配电网供电可靠性直接影响用户的用电质量,应用电力系统分析软件CYME,对配电网进行建模分析。研究比较了不同供电半径和不同典型结构配电网的供电可靠性,并针对实际配电网算例,分析了不同开关动作时间下的配电网可靠性的情况;从各个负荷点可靠性的角度,寻找出该配电网中可靠性较差的负荷点,进而提出了具有针对性的网架优化方案,为配电网可靠性评估分析及应用提供了参考。     

Betaine Alleviates High-Fat Diet-Induced Disruption of Hepatic Lipid and Iron Homeostasis in Mice

Non-alcoholic fatty liver disease (NAFLD) is characterized by excessive fat deposition in the liver, which is often associated with disrupted iron homeostasis. Betaine has been reported to be hepatoprotective, yet whether and how betaine ameliorates high-fat diet-induced disruption of hepatic lipid and iron homeostasis remains elusive. In this study, mice were fed either standard (CON) or high-fat diet (HFD) for 9 weeks to establish a NAFLD model. Mice raised on HF diet were then assigned randomly to HF and HFB groups, HFB group being supplemented with 1% (w/v) of betaine in the drinking water for 13 weeks. Betaine supplementation significantly alleviated excessive hepatic lipid deposition and restored hepatic iron content. Betaine partly yet significantly reversed HFD-induced dysregulation of lipogenic genes such as PRARγ and CD36, as well as the iron-metabolic genes including FPN and HAMP that encodes hepcidin. Similar mitigation effects of betaine were observed for BMP2 and BMP6, the up-stream regulators of hepcidin expression. Betaine significantly rectified disrupted expression of methyl transfer gene, including BHMT, GNMT and DNMT1. Moreover, HFD-modified CpG methylation on the promoter of PRARγ and HAMP genes was significantly reversed by betaine supplementation. These results indicate that betaine alleviates HFD-induced disruption of hepatic lipid and iron metabolism, which is associated with modification of CpG methylation on promoter of lipogenic and iron-metabolic genes.     

A Multifunctional and Fast-Response Lysosome-Targetable Fluorescent Probe for Monitoring pH and Isoxaflutole

A new chemosensor, namely N-(2-morpholinoethyl)acetamide-4-morpholine-1,8-naphthimide (MMN), was designed and synthesized through an amidation reaction. MMN was fabricated as a multifunctional fluorescent probe for monitoring pH and isoxaflutole. MMN exhibited excellent stability in MeCN/H₂O (v/v, 9/1), with an obvious “off–on” fluorescence response toward pH changes due to intramolecular charge transfer (ICT), where the linear response ranges of MMN in the weakly acidic system were from 4.2 to 5.0 and from 5.0 to 6.0 with apparent pK_a = 4.62 ± 0.02 and 5.43 ± 0.02. Based on morpholine as the lysosome targetable unit, MMN could selectively locate lysosomes in live cells. MMN also successfully detected the presence of H⁺ in test papers. Finally, MMN could specifically recognize isoxaflutole at a detection limit of 0.88 μM. A possible sensing mechanism was identified based on density function theory calculations. These results indicate that MMN could be a superior potential chemosensor for detecting pH and isoxaflutole selectively and sensitively and could be used in real sample detection.     

长江大保护下补短板工程的生态治理理念

在长江大保护框架下,针对目前补短板工程治理现状提出河道治理需要融入生态治理理念,可通过建立重要河段水生态保护模拟器,模拟河道系统的污染物、植被措施、水雨情等的变化,既能反映整条河道水生态环境、水量、污染物消纳状况,又能对局部河道的水生态特征进行诊断分析,以便对局部水体的管治提出合理有效的对策,避免局部河段的超标引发整条河道的水生态及水环境恶化。     

不烧Al-Si复合低碳Al2O3-β-SiAlON材料的抗氧化性能

采用大试样高温热重分析仪研究了不烧Al-Si复合低碳Al2O3-β-SiAlON材料(MAC-F)的抗氧化性,并与Al-Si复合不烧铝碳滑板材料(MAC-S)进行了比较。结果表明(1)两种材料在250~1100℃氧化时的质量变化规律相似,在500℃以前均处于质量损失状态;从500℃开始试样处于质量增加状态,500~1100℃之间两种材料质量变化率的增加量差别不大;1100℃以上材料MAC-S的质量变化率的增加量明显提高,而材料MAC-F质量变化率的增加量稍有降低。(2)1500℃氧化后,材料MAC-F质量增加率明显低于材料MAC-S的,氧化层很薄,厚度仅0.5mm。材料MAC-F的氧化层中有较多的短柱状莫来石晶体,均匀地分布在刚玉骨架结构的空隙中,形成致密的结构,对氧气进入材料的内部起到了阻碍作用。其氧化层表面覆盖着一层由莫来石和少量玻璃相组成的光滑薄膜,更有效阻碍了氧气向内部的渗透。因此,材料MAC-F与材料MAC-S相比,抗氧化性能更为优异。     

Generation and Identification of the Number of Copies of Exogenous Genes and the T-DNA Insertion Site in SCN-Resistance Transformation Event ZHs1-2

Soybean cyst nematode (SCN, Heterodera glycines Ichinohe) causes an estimated economic loss of about USD 3 billion each year in soybean (Glycine max L.) production worldwide. Overexpression of resistance genes against SCN provides a powerful approach to develop SCN resistance cultivars in soybean. The clarification of molecular characterization in transformation events is a prerequisite for ecological risk assessment, food safety, and commercial release of genetically modified crops. Here, we generated transgenic events harboring the BCN (beet cyst nematode) resistance Hs1^pro−1 gene using the Agrobacterium-mediated method in soybean, evaluated their resistance to SCN infection, and clarified the molecular characterization of one of the transformation events. Five independent and stable inheritable transformation events were generated by an Agrobacterium-mediated transformation method. SCN resistance tests showed the average number of developed females per plant and female index (FI) in T4 ZHs1-1, ZHs1-2, ZHs1-3, ZHs1-4, and ZHs1-5 transformation events were significantly lower than that in the nontransgenic control. Among these, the ZHs1-2 transformation event had the lowest number of developed females per plant and FI. Southern hybridization showed the exogenous target Hs1^pro−1 gene was inserted in one copy and the Bar gene was inserted two copies in the ZHs1-2 transformation event. The exogenous T-DNA fragment was integrated in the reverse position of Chr02: 5351566–5231578 (mainly the Bar gene expression cassette) and in the forward position of Chr03: 17083358–17083400 (intact T-DNA, including Hs1^pro−1 and Bar gene expression cassette) using a whole genome sequencing method (WGS). The results of WGS method and Southern hybridization were consistent. All the functional elements of exogenous T-DNA fragments were verified by PCR using specific primer pairs in the T5 and T6 ZHs1-2 transformation events. These results demonstrated that the overexpression of Hs1^pro−1 gene enhanced SCN resistance, and provide an important reference for the biosafety assessment and the labeling detection in transformation event ZHs1-2.     

发火控制电路中微执行器

本文针对引信发火控制电路中微执行器输出力矩弱的特点,利用微沟道和凝胶纤维把化学能转化成机械能形变技术,设计了一种新型MEMS微执行器.这种微执行器是通过静电力克服机械弹性力使极板产生相对运动,控制发火控制电路的导通;利用凝胶纤维的收缩力解除引信发火控制电路保险从而达到开启和关闭的目的.文中对所设计的结构进行ANSYS仿真,验证它的可行性并优化了结构参数.这种新型微执行器最大的特点是功耗小,输出功率大,具有很高的机械效率.     

Al2TiO5-SiO2-Al2O3复合材料的研究

以Al2TiO5微细粉、SiO2-Al2O3微细粉为原料,外加6%(质量分数,下同)PVA结合剂,100 MPa压力成型,1400 ℃保温1 h烧成,制备出低热膨胀系数,抗热震性能优于SiO2-Al2O3材料的Al2TiO5-SiO2-Al2O3复合材料.对复合材料的性能测定分析,研究不同的Al2TiO5含量、烧结温度等对Al2TiO5-SiO2-Al2O3复合材料性能的影响,获得了制备性能优良的Al2TiO5-SiO2-Al2O3复合材料的最佳工艺参数.