CMC复合凝胶防灭火机理及其应用

矿井火灾一直是制约煤矿安全生产的重要灾害之一,在诸多防灭火措施中,注浆防灭火的应用十分广泛。矿用CMC复合防灭火凝胶从原料配比和防灭火特性分析,结合实验室的测试印证发现对易燃煤层有良好的效果。CMC复合凝胶胶体制备简单快捷,凝结迅速,在口前煤矿4101工作面采空区使用取得良好效果。     

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.     

大型农机的发展与问题探讨

通过分析大型农机在农业生产实践中发展的必然性和面临的问题,阐述了大型农机在现代农业生产中的作用和发展建议.     

烧碱蒸发扩产节能改造

杭州电化集团有限公司烧碱分厂为满足隔膜电解扩产的需要,将蒸发装置三效四体工艺改为三效五体工艺,并改造了循环冷却水系统,从而提高了装置实际产能,并节约了蒸汽。     

Truly Concomitant and Independently Expressed Short‐ and Long‐Term Plasticity in a Bi2O2Se‐Based Three‐Terminal Memristor

Concomitance of diverse synaptic plasticity across different timescales produces complex cognitive processes. To achieve comparable cognitive complexity in memristive neuromorphic systems, devices that are capable of emulating short‐term (STP) and long‐term plasticity (LTP) concomitantly are essential. In existing memristors, however, STP and LTP can only be induced selectively because of the inability to be decoupled using different loci and mechanisms. In this work, the first demonstration of truly concomitant STP and LTP is reported in a three‐terminal memristor that uses independent physical phenomena to represent each form of plasticity. The emerging layered material Bi₂O₂Se is used for memristors for the first time, opening up the prospects for ultrathin, high‐speed, and low‐power neuromorphic devices. The concerted action of STP and LTP allows full‐range modulation of the transient synaptic efficacy, from depression to facilitation, by stimulus frequency or intensity, providing a versatile device platform for neuromorphic function implementation. A heuristic recurrent neural circuitry model is developed to simulate the intricate “sleep–wake cycle autoregulation” process, in which the concomitance of STP and LTP is posited as a key factor in enabling this neural homeostasis. This work sheds new light on the development of generic memristor platforms for highly dynamic neuromorphic computing.     

Self-assembly synthesis of cactuslike Cu2O 3D nanoarchitectures via a low-temperature solution approach

Cu₂O nanocactuses were synthesized via a simple, low-temperature, and no time-consuming wet chemical route. The synthesized products were systematically studied by X-ray powder diffraction, scanning electron microscopy, and transmission electron microscopy. The results showed that the formation of Cu₂O nanocactuses was strongly depended on the addition of CTAB and NaOH. The structural evolution of the cactuslike Cu₂O was found to follow dissolution and recrystallization processes. It is noteworthy that the stepwise synthetic procedure was crucial to the growth of the final nanoarchitectures. UV–vis spectrum was also used to estimate the absorption and photodegradation ability of the nanocactuses.     

Expression Patterns of Sugar Transporter Genes in the Allocation of Assimilates and Abiotic Stress in Lily

During the growth cycle of lilies, assimilates undergo a process of accumulation, consumption and reaccumulation in bulbs and are transported and allocated between aboveground and underground organs and tissues. The sink–source relationship changes with the allocation of assimilates, affecting the vegetative growth and morphological establishment of lilies. In this study, the carbohydrate contents in different tissues of five critical stages during lily development were measured to observe the assimilates allocation. The results showed bulbs acted as the main source to provide energy before the budding stage (S3); after the flowering stage (S4), bulbs began to accumulate assimilates as a sink organ again. During the period when the plant height was 30cm with leaf-spread (S2), leaves mainly accumulated assimilates from bulbs through the symplastic pathway, while when leaves were fully expanded, it transformed to export carbohydrates. At the S4 stage, flowers became a new active sink with assimilates influx. To further understand the allocation of assimilates, 16 genes related to sugar transport and metabolism (ST genes) were identified and categorized into different subfamilies based on the phylogenetic analysis, and their protein physicochemical properties were also predicted. Tissue-specific analysis showed that most of the genes were highly expressed in stems and petals, and it was mainly the MST (monosaccharide transporter) genes that were obviously expressed in petals during the S4 stage, suggesting that they may be associated with the accumulation of carbohydrates in flowers and thus affect flower development process. LoSWEET14 (the Sugar will eventually be exported transporters) was significantly correlated with starch in scales and with soluble sugar in leaves. Sugar transporters LoHXT6 and LoSUT1 were significantly correlated with soluble sugar and sucrose in leaves, suggesting that these genes may play key roles in the accumulation and transportation of assimilates in lilies. In addition, we analyzed the expression patterns of ST genes under different abiotic stresses, and the results showed that all genes were significantly upregulated. This study lays a solid foundation for further research on molecular mechanism of sink–source change and response to abiotic stresses in lilies.     

保健食品建泽泻及其混淆品的PCR-RFLP分子鉴别

目的:寻找简易可重复的分子标记方法对保健食品建泽泻及其混淆品进行鉴定。方法:对建泽泻及其混淆品的rDNA ITS区进行PCR扩增、测序,运用ClustalX、Mega3.0、DNAMAN 4.0等软件对ITS区进行序列分析和PCR限制性酶切图谱分析(PCR-RFLP)。结果:依据建泽泻及其混品完整的rDNA ITS区片段长度,将慈菇和甘薯两种混淆品首先区分开;再通过PCR-RFLP分析,可将建泽泻从川泽泻、窄叶泽泻、小泽泻和芋等混淆品中成功鉴别出来。结论:rDNA ITS片段长度不足以用于鉴别保健食品建泽泻原料的真伪;PCR-RFLP可对保健食品建泽泻及其混淆品进行简便而快捷的分子鉴别。     

Modulating lateral strain in GaN-based epitaxial layers by patterning sapphire substrates with aligned carbon nanotube films

A novel carbon nanotube-patterned sapphire substrate (CPSS) has been utilized for the growth of GaN material and fabrication of a InGaN/GaN light emitting diode (LED) by metal-organic vapor phase epitaxy. Different lateral strain distributions and stress reductions were observed in a GaN thin film on CPSS compared with those on a conventional sapphire substrate. Nanoheteroepitaxy induced by small size nucleation islands of about 50 nm is ascribed to this significant strain modulation. The crystalline quality of the GaN thin film was also improved, as illustrated by X-ray diffraction. Performances of 1 mm × 1 mm LEDs on CPSS were also enhanced, with an operational power increase of 37.5% and higher saturation current.