藏东地区优先发展微水电的几点思考

解决西藏农牧区分散居民用电一直是并网型能源技术难以克服的问题之一,离网型微水电具有投资小、运行维护简单、对环境没有影响等技术经济优势,适合人口稀少并分散的横断山脉地区。因此,发展微水电是目前解决分散农牧民用电问题比较可行的途径。     

Eugenol-Containing Siloxane Synthesized Via Heterogeneous Catalytic Hydrosilylation and its Application in Preparation of Superb Viscoelastic Low Modulus Gels

Silicon - Eugenol is widely used as bio-based raw materials, based on functional groups such as hydroxyl, methoxy, and allyl contained in the molecule that has van der Waals forces or chemical...     

Room temperature in-situ preparation of hydrazine-linked covalent organic frameworks coated capillaries for separation and determination of polycyclic aromatic hydrocarbons

Covalent organic frameworks (COFs) have been increasingly used in capillary electrochromatography due to their excellent characteristics. In this work, hydrazine-linked TFPB-DHzDS (TFPB: 1,3,5-tris(4-formylphenyl)benzene; DHzDS: 2,5-bis(3-(ethylthio)propoxy)terephthalohydrazide) was first synthesized by a simpler and easier method at room temperature and introduced into capillary electrochromatography as coating material. The TFPB-DHzDS coated capillaries were prepared by an in-situ growth process at room temperature. After optimizing the coating concentration and experimental conditions of capillary electrochromatography, baseline separation of two groups of polycyclic aromatic hydrocarbons was achieved based on the TFPB-DHzDS coated capillary. And the established method was used successfully to determine PAHs in natural water and soil samples. The spiked recoveries of polycyclic aromatic hydrocarbons in these samples ranged from 90.01% to 111.0%, indicating that the method is reliable and could detect polycyclic aromatic hydrocarbons in natural samples. Finally, molecular simulation was applied to study and visualize the interaction between the analytes and coating COF materials to investigate the molecular level separation mechanism further.     

调节阀与流量计构成的闭环系统

本文介绍了位置调节阀与流量计组成的流量控制闭环系统。详细描述系统构成和其功能、并介绍了阀的调整和使用以及PID参数调整的方法。     

防止引风机叶片积灰震动的数值分析

本文采用SIMPLE算法对引风机在安装防止叶片积灰振动的装置后,不同工况时的流场进行了单相或气固两相流动的数值模拟,通过分析流场的特点和粒子的运动轨迹,验证了该装置的实际使用效果.     

Comparison of Gut Bacterial Communities of Grapholita molesta (Lepidoptera: Tortricidae) Reared on Different Host Plants

Intestinal symbiotic bacteria have played an important role in the digestion, immunity detoxification, mating, and reproduction of insects during long-term coevolution. The oriental fruit moth, Grapholita molesta, is an important fruit tree pest worldwide. However, the composition of the G. molesta microbial community, especially of the gut microbiome, remains unclear. To explore the differences of gut microbiota of G. molesta when reared on different host plants, we determined the gut bacterial structure when G. molesta was transferred from an artificial diet to different host plants (apples, peaches, nectarines, crisp pears, plums, peach shoots) by amplicon sequencing technology. The results showed that Proteobacteria and Firmicutes are dominant in the gut microbiota of G. molesta. Plum-feeding G. molesta had the highest richness and diversity of gut microbiota, while apple-feeding G. molesta had the lowest. PCoA and PERMANOVA analysis revealed that there were significant differences in the gut microbiota structure of G. molesta on different diets. PICRUSt2 analysis indicated that most of the functional prediction pathways were concentrated in metabolic and cellular processes. Our results confirmed that gut bacterial communities of G. molesta can be influenced by host diets and may play an important role in host adaptation.     

Oxidation State Modulation of Bismuth for Efficient Electrocatalytic Nitrogen Reduction to Ammonia

Electrocatalytic nitrogen reduction reaction (NRR) is a promising strategy for ammonia (NH₃) production under ambient conditions. However, it is severely impeded by the challenging activation of the NN bond and the competing hydrogen evolution reaction (HER), which makes it crucial to design electrocatalysts rationally for efficient NRR. Herein, the rational design of bismuth (Bi) nanoparticles with different oxidation states embedded in carbon nanosheets (Bi@C) as efficient NRR electrocatalysts is reported. The NRR performance of Bi@C improves with the increase of Bi⁰/Bi³⁺ atomic ratios, indicating that the oxidation state of Bi plays a significant role in electrochemical ammonia synthesis. As a result, the Bi@C nanosheets annealed at 900  ° C with the optimal oxidation state of Bi demonstrate the best NRR performance with a high NH₃ yield rate and remarkable Faradaic efficiency of 15.10  ± 0.43% at − 0.4 V versus RHE. Density functional theory calculations reveal that the effective modulation of the oxidation state of Bi can tune the p-filling of active Bi sites and strengthen adsorption of *NNH, which boost the potential-determining step and facilitate the electrocatalytic NRR under ambient conditions. This work may offer valuable insights into the rational material design by modulating oxidation states for efficient electrocatalysis.     

管形TEG的等离子喷涂制备及其热电性能

热电器件(Thermoelectric generator,TEG)利用材料内部载流子运动可实现对低品质余废热能的回收利用。相较于热电材料的发展,TEG制备技术的滞后制约了TEG的广泛应用。针对上述问题,探索使用灵活、高成本效益的等离子喷涂技术制备高锰硅(Higher manganese silicide,HMS)基管形TEG的可行性,详细描述了层积型TEG的喷涂制备过程,并对高锰硅热电沉积层的物相组织、微观形貌进行表征,最后测试管形TEG热电P-N单元的热电输出性能。结果表明,等离子喷涂制备的多层复合结构管形TEG成形良好;高锰硅沉积层作为热电功能层,喷涂后保持与原始粉末相同的HMS主体相,同时沉积层的快速冷却过程减少了杂质Si相的残余;管形TEG在自然散热工况下,当柱状热源为450℃时单个P-N单元电压输出可达24.69 m V,满足超低压收集装置的电压输入要求。