汉江上游干支流沉积物细菌群落多样性和影响因素

为了解汉江上游干支流沉积物细菌多样性以及确定性过程和随机性过程在沉积物细菌群落构建过程中的相对重要性,基于Illumina高通量测序技术,分析了环境因子对细菌群落组成的影响,采用非度量多维尺度(NMDS)排序探究了季节之间沉积物细菌群落的差异,并结合中性群落模型和标准化随机率量化了确定性过程和随机过程对群落构建的影响。结果表明:汉江上游及其支流细菌群落主要由变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、蓝藻门(Cyanophyta)、浮霉菌门(Planctomycetes)和酸杆菌门(Acidobacteria)等组成；细菌群落在不同季节有显著差异；地理距离和环境因子对细菌群落结构影响较小,确定性过程并未在细菌群落组成中起到主导作用；随机过程很大程度上影响了群落在秋季和春季的组成,是沉积物细菌群落构建的主导因素。     

Improved thermal stability of the near-infrared Al-modulated Zn3Ga2GeO8: Cr3+ phosphors for plant growth applications

The exploration of the high thermal stability near-infrared (NIR) phosphors is significantly crucial for the development of plant lighting. However, NIR phosphors suffer from the poor chemical and thermal stability, which severely limits their long-term operation. Here, the successful improvement of luminous intensity (149.5%) and thermal stability at 423 K of Zn₃Ga₂GeO₈ (ZGGO): Cr³⁺ phosphors is achieved for the introduction of Al³⁺ ions into the host. The release of carriers in deep traps inhibits the emission loss for the thermal disturbance. Furthermore, an NIR light emitting diodes (LEDs) lamp is explored by combining the optimized Zn₃Ga_1.1675Al_0.8GeO₈: 0.0325Cr³⁺ phosphors with a commercial 460 nm blue chip, and the emission band can match well with the absorption bands of photosynthetic pigments and the phytochrome (P_R and P_FR) of plants. The explored LEDs lamp further determines the growth and the pheromone content of the involved plants for the participation of the NIR emission originated from Cr³⁺ ions. Our work provides a promising NIR lamp as plant light with improved thermal stability for long-term operation.     

Far-red-emitting YAl3(BO3)4:Cr3+ phosphors with excellent thermal stability and high luminescent yield for plant growth LEDs

Phosphors-converted LEDs (pc-LEDs) are excellent artificial light sources for indoor plant cultivation, in which the far-red-emitting component (700−780 nm) plays an important role in regulating the photomorphogenesis of plants. Accordingly, highly efficient and thermally stable far-red-emitting phosphors are indispensable for developing high-performance plant cultivation pc-LEDs. Herein, far-red-emitting YAl₃(BO₃)₄:Cr³⁺ (YAB:Cr³⁺) phosphors were synthesized by solid-state reaction, and their photoluminescence characteristics, thermal quenching, quantum yield (QY), and application in pc-LEDs were systematically investigated. The YAB:Cr³⁺ phosphor has an intense broadband absorption to the blue light, simultaneously exhibiting the sharp-line ²E emission and the broadband ⁴ T₂ emission of Cr³⁺ with a QY of ~86.7%. The far-red broadband emissions of YAB:Cr³⁺ centered at ~735 nm show a high resemblance to the active-state (P_FR) absorption of plant phytochrome. Moreover, the YAB:Cr³⁺ phosphor shows the thermally enhanced luminescence at temperatures of 303−393 K and the near-zero thermal quenching up to 423 K. The anomalous thermal enhancement is attributed to the temperature-dependent repopulation between ²E and ⁴ T₂ states. Finally, a pc-LED device was fabricated with the YAB:Cr³⁺ phosphor and blue chip, exhibiting the light out power of ~50.6 mW and energy conversion efficiency of ~17.4% at 100 mA drive current, respectively. The exceptional PL features including suitable excitation/emission wavelengths, suppressed thermal quenching and high QY make YAB:Cr³⁺ phosphors very promising for applications in plant growth pc-LEDs.     

多堆厂址始发事件分析探讨

多堆厂址一级概率安全评价（PSA）研究中，机组数目的增加使得建模工作量剧增，给整个核电厂的风险评估带来困难。结合已有基础，本文研究了多堆厂址始发事件分析的筛选方法，提出利用堆芯损伤频率（CDF）上下限值评估方法，分析厂址内不同机组数对厂址CDF的影响。结果表明，双机组厂址适合优先进行具体分析。针对双机组核电站，对多堆厂址内各始发事件进行筛选。结果表明，丧失厂外电、丧失热阱等事件适合建模分析，并对其他筛选结果给出后续分析建议，为多堆厂址一级PSA后续事故序列建模工作提供了重要基础。     

Physicochemical and thermophysical properties of CaO–TiO2–SiO2–Na3AlF6 system based electrode coating for AUSC power plant

The aim of this study is to investigate the physicochemical and thermophysical properties of CaO–TiO₂–SiO₂–Na₃AlF₆ based electrode coating developed for the welding of advanced ultra-supercritical (AUSC) thermal power plant components. The extreme vertices approach has been used to create twenty-six electrode coating compositions. Various physicochemical and thermophysical properties were characterized using experiments. The coating properties are essential in ensuring sound weld with desirable in-service performance. The developed coating's structural behavior was analyzed using Fourier transformation infrared spectroscopy (FTIR) and X-ray diffraction (XRD). In addition, regression analysis was carried out to evaluate the influence of coating constituents. Individual constituents and their interaction were found to have a prominent role in influencing the physicochemical and thermophysical properties.     

Exergy analysis and optimisation of waste heat recovery systems for cement plants

In the last decades, heat recovery systems have received much attention due to the increase in fuel cost and the increase in environmental issues. In this study, different heat recovery systems for a cement plant are compared in terms of electricity generation and exergy analysis. The heat sources are available in high temperature (HT) and low temperature (LT). For the HT section a dual pressure Rankine cycle, a simple dual pressure Organic Rankine Cycle (ORC) and a regenerative dual pressure ORC are compared. Also, for the LT section, a simple ORC is compared with transcritical carbon dioxide cycle. To find the best system, an optimisation algorithm is applied to all proposed cycles. The results show that for the HT section, regenerative ORC has the highest exergy efficiency and has the capability of producing nearly 7?MW electricity for a cement factory with the capacity of 3400 ton per day. The main reason for this is introducing the regenerative heat exchanger to the cycle. For the LT section, ORC showed a better performance than the CO₂ cycle. It is worth mentioning that the generated power in this section is far lower than that of the HT section and is equal to nearly 300?kW.     

第二代高通量测序技术分析倒笃菜菌群

目的检测収酵食品倒笃菜中细菌和真菌菌群结构。方法利用第二代高通量测序对倒笃菜中的真菌和细菌菌群结构迚行测定分析。结果检测出倒笃菜产品中,细菌群落中占主要地位为假单胞菌属(Pseudomonas)、拟杆菌属(Bacteroides)和Faecalibacterium属,分别占比例为11.4%、9.3%和8.9%,而对収酵起至兲重要的芽孢乳杆菌属(Lactobacillus)仅占比例为1.1%。倒笃菜中真菌群落中占主要地位的真菌菌属为曲霉属(Aspergillus),占比为88.8%,而其余真菌占比仅为11.2%。其中,曲霉真菌属中存在可以产生真菌毒素的黄曲霉菌(A.flavus)、寄生曲霉菌(A.parasiticus)等。结论结果表明传统腌制倒笃菜产品中可能会存在一定的致病细菌与可产真菌毒素的真菌,从而有引起食品安全问题的风险,因此,应迚一步对倒笃菜微生物的安全性迚行深入检测分析。     

Nature inspired 21 branches sneezewort/Achillea ptarmica plant growth pattern–shaped antenna for Ku‐band applications

This reported paper presents the design and analysis of wideband nature inspired planar antenna of 46 × 18 × 1.6 mm³ size, designed using FR4 (Flame Retardant) substrate. The antenna patch is delineated from the growth pattern of sneezewort plant with supplementary notion of golden ratio in branching and branch width. The total number of branches in each stage follows the Fibonacci series and the branch width is calculated from the golden ratio concept. Starting from one feed line and two branches, the maximum numbers of branches are increased to 20. There has been significant enhancement in the radiation performance of proposed geometry by increasing the number of branches to 21 and by modifying ground with T‐shaped slot. The antenna covers wide impedance bandwidth of 8.2 to 16.5 GHz by possessing stable radiation characteristics.