Exploration of CoSi-based alloys promising for thermoelectricity

The cobalt silicide CoSi seems a suitable material for thermoelectricity: it is inexpensive and non-toxic, but its thermal conductivity is large. Forming CoSi-based alloys by replacing part of Co or Si with a heteroatom M can change electronic properties and improve thermoelectric performances. The insertion energy of different CoSi-based alloys containing abundant, inexpensive and non-toxic elements was estimated by using DFT calculations. Several alloys were synthesized using arc-melting or powder reaction and then characterized using X-Rays powder Diffraction (XRD) and Electron Micro Probe Analysis (EMPA) to determine the limit of solubility of these heteroatoms within CoSi. DFT predictions of solubility limit were in qualitative agreement with experimental results. Vibrational and thermoelectric properties were measured for alloys containing highly soluble elements (Mn and Cr) but also poorly soluble ones (Ti and V). These new CoSi-based alloys, studied for the first time for thermoelectric applications, do not exhibit a notable improvement of the performances.     

Anisotropic magnetoresistivity and magnetic entropy change in HoAl2

We report a correlation between magnetoresistivity Δρ_mag and magnetic entropy change ΔS_mag for specified crystallographic directions of a HoAl₂ single crystal. This ferromagnetic compound shows differentiated behavior among the members of the RAl₂ series due to the presence of spontaneous spin reorientation. We discussed this effect in order to establish a relationship between the two quantities studied. The calculations were performed using a self-consistent model based on a Hamiltonian containing exchange, Zeeman and crystal field terms. We found that the normalized relation {Δρ_mag} = (T/T_C)^m{ΔS_mag}, with m = 0.1 for the [100] and [110] directions matches satisfactorily the two quantities.     

Daytime Radiative Cooling: Artificial and Bioinspired Strategies

Traditional cooling systems have been posing a significant challenge to the global energy crisis and climate change due to the high energy consumption of the cooling process. In recent years, the emerging daytime radiative cooling provides a promising solution to address the bottleneck of traditional cooling technology by passively dissipating heat radiation to outer space without any energy consumption through the atmospheric transparency window(8～13μm). Whereas its stringent optical criteria require sophisticated and high cost fabrication producers, which hinders the applicability of radiative cooling technology. Many efforts have been devoted to develop high-efficiency and low-cost daytime radiative cooling technologies for practical application, including the nanophotonics based artificial strategy and bioinspired strategy. In order to systematically summarize the development and latest advance of daytime radiative cooling to help developing the most promising approach, here in this paper we will review and compare the two typical strategies on exploring the prospect approach for applicable radiative cooling technology. We will firstly sketch the fundamental of radiative cooling and summarize the common methods for construction radiative cooling devices. Then we will put an emphasis on the summarization and comparison of the two strategies for designing the radiative cooling device, and outlook the prospect and extending application of the daytime radiative cooling technology.     

好氧颗粒污泥处理印染废水的特性探究

在柱状序批式反应器内调查了好氧颗粒污泥处理印染废水的可行性,并考察进水有机负荷率（OLR）对颗粒污泥形成规律及COD、氨氮的去除影响。结果表明,当进水OLR由1.0 kg/（m³·d）升高至7.0 kg/（m³·d）时,颗粒污泥质量浓度呈现上升趋势。当进水OLR为5.0 kg/（m³·d）时,颗粒污泥系统沉降性最好,污泥沉降指数(SVI₃₀)仅为52.6m L/g。此外,进水OLR影响颗粒污泥粒径分布、胞外聚合物（EPS）含量及组分。当进水OLR为5.0 kg/（m³·d）时,颗粒污泥粒径主要分布于0.9～1.2 mm,且占比38.5%,EPS的含量升高至81.3 mg/g,显著高于其他进水OLR组别。进水OLR变化主要影响EPS内蛋白质（PN）含量变化,而对多糖（PS）含量变化影响较小。进水OLR能影响颗粒污泥处理印染废水中污染物的去除,当进水OLR为5.0 kg/（m³·d）时,COD和氨氮去除率最高,且分别为79.5%和85.6%,而进水OLR对浊度...     

分段进水比对两级A/O-海绵填料工艺处理DMF废水的影响

采用两级A/O-海绵填料工艺处理DMF废水,探究一级A/O缺氧池(A1)和二级A/O缺氧池(A2)分段进水比(8∶2、7∶3、6∶4、5∶5)对系统脱氮除碳效能影响。结果表明,两级A/O-海绵填料工艺在不同分段进水比条件下均能实现对COD的高效去除,COD平均去除率均达到95%以上,而系统对TN、NO;-N和NH;-N的去除受分段进水比影响较大。在较高(8∶2和7∶3)分段进水比条件下,系统TN去除率为81.39%~89.03%,此时TN主要以NH₄⁺-N和NO₃^--N形式存在;当分段进水比减小为6∶4时,系统TN去除率达到最优值91.33%,出水NH₄⁺-N和NO₃^--N均明显低于其余进水比工况,分别降至8.04 mg/L和7.06 mg/L。因此通过优化两级A/O-海绵填料工艺分段进水比,可提升高浓度有机氮废水中难降解碳源的利用率与控制氨化反应进程,实现DMF废水有机氮的高效去除。     

反硝化除磷+短程反硝化厌氧氨氧化工艺的深度脱氮除磷效能

为经济高效地去除城市生活污水和硝酸盐废水中的氮磷元素,本研究在厌氧折流板反应器（ABR）和连续搅拌反应器（CSTR）一体式反应器中分别建立了反硝化除磷（DPR）和短程反硝化厌氧氨氧化（PDA）工艺。结果表明,反应器运行185天,在缺氧/厌氧和外加COD/NO{}_{\mathrm{3}}^{-}-N比仅为0.7条件下,PO{}_{\mathrm{4}}^{\mathrm{3}-}-P和TN的去除率高达96.91%和97.75%,最终出水PO{}_{\mathrm{4}}^{\mathrm{3}-}-P和TN的浓度低至0.22mg/L和3.30mg/L,意味着该系统极佳的脱氮除磷效果不依赖氧气和有机碳源量。DPR对系统PO{}_{\mathrm{4}}^{\mathrm{3}-}-P和TN的去除均占主体部分（99.07%和60.23%）,而PDA对总氮（TN）的去除占比呈现逐渐上升的趋势（4.53%→37.52%）。批次实验表明：①COD（300mg/L）显著抑制DPR菌活性,PO{}_{\mathrm{4}}^{\mathrm{3}-}-P主要是在缺氧状态下以NO{}_{\mathrm{3}}^{-}-N为电子受体,有机物为电子供体通过DPR途径去除;②高效短程反硝化过程（亚硝酸转化率92.25%）稳定为厌氧氨氧化供给电子受体（NO{}_{\mathrm{2}}^{-}-N）,DPR系统剩余NH{}_{\mathrm{4}}^{+}-N主要被NO{}_{\mathrm{2}}^{-}-N氧化去除,因此DPR+PDA系统实现了高效同步脱氮除磷效果。高通量测序表明,Accumulibacter（7.41%）是DPR系统功能性除磷菌,Thauera（7.24%）和Candidatus Brocadia（3.12%）为PDA系统关键脱氮菌。     

The Effect of a Polymeric Flame Retardant Containing Phosphorus–Sulfur–Silicon and a Caged Group on Unsaturated Polyester Resin

Journal of Inorganic and Organometallic Polymers and Materials - Currently, the issue of natural flammability of unsaturated polyester resin (UPR) severely restrains its application. In this study,...     

亚铁还原土壤浸滤液中六价铬的影响因素及稳定性探究

文章以Fe(Ⅱ)为还原剂,土壤浸滤液中Cr(Ⅵ)为处理对象,研究了处理效果与pH、氧化还原条件和反应时间的关系。结果表明在pH为中性,厌氧的条件下Fe(Ⅱ)对于Cr(Ⅵ)具有较好的还原效果。在一个月的反应时期内曝气组中Cr(Ⅵ)呈现先降低后增加的趋势,建议在实施化学还原技术修复土壤重金属铬污染的时候结合微生物以及固定化等技术联合治理。     

豆腐渣厌氧消化产沼气的试验研究

本试验以新鲜豆腐渣为沼气发酵原料,控制厌氧消化温度35±2℃的条件下,采用一次性投料,进行厌氧消化产沼气试验,结果表明:豆腐渣是良好的沼气发酵原料,通过分析消化系统pH值、挥发性脂肪酸(VFA)、日产气量和气体成分的变化可知,在投料比(渣泥质量比)为1∶5、1∶2、1∶1时消化系统的变化是一个正常的水解酸化过程,其单位产气率分别为0.87 L/g TS、1.43 L/g TS、0.93 L/g TS。其中投料比为1∶5的消化系统产生的甲烷含量最高可达81.03%,平均甲烷含量为49.95%。而投料比为2∶1、5∶1的消化系统均出现了酸抑制现象,系统不能顺利进入产甲烷阶段。     

苏州市餐厨垃圾产量调查分析

对苏州市餐厨垃圾现状进行问卷调查,掌握了苏州市餐厨垃圾产量、收运以及处置现状,并对典型餐厨垃圾的理化性质进行分析。调查结果显示:苏州市餐厨垃圾年产量约为35万吨。餐饮业、高校及企事业单位食堂人均餐厨垃圾产生量分别为0.35 kg/(人·次)、0.13 kg/(人·次)、0.24 kg/(人·次)。