Use of MALDI-TOF MS technology to evaluate adulteration of small ruminant milk with raw bovine milk

Detection of adulteration of small ruminant milk is very important for health and commercial reasons. New analytical and cost-effective methods need to be developed to detect new adulteration practices. In this work, we aimed to explore the ability of the MALDI-TOF mass spectrometry to detect bovine milk in caprine and ovine milk using samples from 18 dairy farms. Different levels of adulteration (0.5, 1, 5, 10, 20, 40, 60, and 80%) were analyzed during the lactation period of goat and sheep (in May, from 60 to 90 d in milk, and in August, from 150 to 180 d in milk). Two different ranges of peptide-protein spectra (500–4,000 Da; 4–20 kDa) were used to establish a calibration model for predicting the concentration of adulterant using partial least squares and generalized linear model with lasso regularization. The low molecular weight part of the spectra together with the generalized linear model with lasso regularization regression model appeared to have greater potential for our aim of detection of adulteration of small ruminants' milk. The subsequent prediction model was able to predict the concentration of bovine milk in caprine milk with a root mean square error of 11.4 and 17.0% in ovine milk. The results offer compelling evidence that MALDI-TOF can detect the adulteration of small ruminants' milk. However, the method is severely limited by (1) the complexity of the milk proteome resulting from the adulteration technique, (2) the potential degradation of thermolabile proteins, and (3) the genetic variability of tested samples. Additionally, the root mean square error of prediction based only on one individual sample adulteration series can drop down to 6.34% for quantification of adulterated caprine milk and 6.28% for adulterated ovine milk for the full set of concentrations or down to 2.33 and 4.00%, respectively, if we restrict only to low concentrations of adulteration (0, 0.5, 1, 5, 10%).     

南水北调中线水源区浮游植物群落结构 及其生物多样性

为探究南水北调中线水源区丹江口水库浮游植物群落结构变化及其生物多样性，于 2014—2015 年对丹江 口水库进行为期 1 年的调查和分析。发现浮游植物共 8 门 76 属 101 种，其中，绿藻门、蓝藻门及硅藻门占总种数 90.10%，绿藻门种类数最多（45 种），其次是蓝藻门（26 种）和硅藻门（20 种）。浮游植物群落结构随季节变化有所 不同：夏秋季节生物量明显高于冬春季节；优势种在冬季以颗粒直链藻、颗粒直链藻极狭变种、铜绿微囊藻和小 环藻为主，春季以球衣藻、薄甲藻属及小环藻为主，夏季以简单颤藻、单胞衣藻原变种和球衣藻为主，秋季以类颤 藻鱼腥藻、简单颤藻、球衣藻和小环藻为主。应用 Shannon-Wiener 多样性指数 H′、Pielou 均匀度指数 J′、Margalef 丰富度指数 Dm评价水质结果表明：丹江口水库夏秋季水体营养化程度更高。典型对应分析表明：水温、透明度、 总氮、总磷等是影响浮游植物群落结构的主要环境因子，夏秋季受温度影响蓝藻、绿藻数量逐渐增多，一定程度 上增加了受水区生态变化风险。本研究可为南水北调中线水源区丹江口水库生态环境变化及生物迁移风险提供 数据支持。     

分布式多元随机动态场景生成及快速精准场景降维算法

高比例新能源及多源耦合是电力系统发展的重要特征,这也为系统稳定经济运行提出了新挑战。该文以园区型多能系统为对象,研究了分布式多元随机动态场景分析,从多时空角度有效量化不确定因素给系统造成的影响,可为系统灵活重构、多维度协同运行与决策提供有力模型与场景支撑。首先由预测误差驱动拟合多元功率预测误差概率分布,全面反映随机功率出力信息,提高模型泛化性;以时序相关范围参数为数据驱动关联变量,高效动态控制波动强度;最终场景生成利用逆变换映射思想保证置信度。然后针对典型场景提取,提出一种综合递归聚类思想的多段嵌套削减算法,结合改进Wasserstein距离指标,兼具准确、时效、稳定方面的优势。最后由对比实验论证该方法的前沿有效性。     

奉御董造与禁廷制样:两宋地方官窑执行的御用瓷设计制度

宋朝兴起的地方官窑为宫廷烧造御用瓷是官手工业发展的亮点之一,并逐步形成了两宋地方官窑执行的御用瓷设计制度,设计制度形成绝非偶然,它是宋朝强化皇权意志、器用制度与地方精湛制瓷工艺共同作用的结果。地方官窑主要执行有奉御董造制度、禁廷制样制度。体现的御用瓷设计制度特征十分明显:前期是指专门接受宫廷敕命,由专官管理,奉御烧造宫廷各种用瓷,有命则供,否则止;后期是指宫廷对御用瓷有专门的设计图式,特由礼部礼制局彩画制样后,向地方官窑降发图样烧造御用瓷。尤其是地方官窑执行的禁廷制样须索制度为明代御器厂和清代御窑厂所继承。     

电子探针面分析法测定钢的脱碳层深度

提出钢表层脱碳层深度测定的一种新方法,即电子探针面分析法。对热轧态高碳工具钢75Cr1、淬火齿轮钢20CrMnTi、冷轧退火低碳车厢板SH1100钢3个典型钢种完成脱碳层深度的测定试验,结果表明:对于珠光体-铁素体型中高碳钢的脱碳层深度测定,金相法测定值是电子探针面分析法测定值的77%左右;对于淬回火钢的脱碳层深度测定,电子探针面分析法的测量精度在10 μm以下,约是显微硬度法测量精度的十分之一;对于脱碳层深度不易准确测定的低碳钢,电子探针面分析法通过较大区域范围的平均碳含量变化曲线来测定脱碳层深度,测量结果准确。电子探针面分析法在脱碳层深度测定方面具有钢种组织状态不限、试样形状不限、数据统计性好、测量精度高、易操作等优势,可在业内大力推广。     

Thermal stability of the nanolayered Fe2AlB2 in nitrogen and argon atmospheres

The thermal stability and decomposition mechanisms of Fe₂AlB₂ powders, synthesized by reactive powder metallurgy, were studied under nitrogen (N₂) or argon (Ar) atmospheres. The effects of using different FeB precursors to synthesize the Fe₂AlB₂ and hydrochloric acid (HCl) purification treatments on the thermal stability were also investigated. When as-synthesized Fe₂AlB₂ powders are treated in dilute HCl to dissolve impurity phases, decomposition in N₂ atmospheres occurs readily above 1200 K. The decomposition reaction involves β-FeB precipitation and the liberated Al atoms reacting with the ambient N₂ to form AlN. Under Ar environments, HCl-treated Fe₂AlB₂ powders decompose and precipitate β-FeB, by the out-diffusion of Al from the nanolaminated structure. Interestingly, isothermal annealing under N₂ atmospheres revealed that Fe₂AlB₂ was more thermally stable when synthesized from lab-synthesized, instead of commercially available, FeB precursors and when the HCl treatment was avoided. The effects of the various factors on the decomposition temperature and decomposition mechanisms are discussed herein.     

Suppressed Lattice Disorder for Large Emission Enhancement and Structural Robustness in Hybrid Lead Iodide Perovskite Discovered by High-Pressure Isotope Effect

The soft nature of organic–inorganic halide perovskites renders their lattice particularly tunable to external stimuli such as pressure, undoubtedly offering an effective way to modify their structure for extraordinary optoelectronic properties. Here, using the methylammonium lead iodide as a representative exploratory platform, it is observed that the pressure-driven lattice disorder can be significantly suppressed via hydrogen isotope effect, which is crucial for better optical and mechanical properties previously unattainable. By a comprehensive in situ neutron/synchrotron-based analysis and optical characterizations, a remarkable photoluminescence (PL) enhancement by threefold is convinced in deuterated CD₃ND₃PbI₃, which also shows much greater structural robustness with retainable PL after high peak-pressure compression–decompression cycle. With the first-principles calculations, an atomic level understanding of the strong correlation among the organic sublattice and lead iodide octahedral framework and structural photonics is proposed, where the less dynamic CD₃ND₃⁺ cations are vital to maintain the long-range crystalline order through steric and Coulombic interactions. These results also show that CD₃ND₃PbI₃-based solar cell has comparable photovoltaic performance as CH₃NH₃PbI₃-based device but exhibits considerably slower degradation behavior, thus representing a paradigm by suggesting isotope-functionalized perovskite materials for better materials-by-design and more stable photovoltaic application.     

Highly thermal stable electron-transporting materials using triptycene derivatives for OLEDs

Highly thermal stable two-electron transport materials (ETMs) based on the triptycene containing phenylpyridine derivatives were designed and synthesized by Suzuki-Miyaura coupling reactions efficiently. Among them, TPP shows a high triplet energy gap (E_T = 2.85 eV), high glass transition temperature (T_g = 142 °C), deep HOMO level (7.0 eV) and good electron mobility. TPP performed as ETM for the green phosphorescent OLED was achieved high external quantum efficiency (EQE) compared to that of the device with TmPyPB as ETM. Moreover, thermal stability was demonstrated after thermal annealing of the device at 100 °C for 30 min, resulting in the TPP-based device reached a high EQE of 13.6% at a luminance of 100 cd m⁻², while that of TmPyPB-based device have dramatically degraded under otherwise identical conditions.     

Collineation measurement: A method for constructing the imperial citadel of Thang Long in harmony with nature

The Imperial Citadel of Thang Long is a crucial case in ancient Vietnam’s planning and design history. Although historical materials indicate that the orientation of the Imperial Citadel of Thang Long has a dialectical unity relationship with the surroundingmountains, current research is only speculative generalization and lacks empirical analysis. Based on existing findings, this paper identifies the collineation measurement as a generalmethod in the Sinosphere countries for determining spatial orientation. Using a mixed-method of historical archives, fieldwork and simulation model, this paper summarizeshistorical cluesandthreedesignperspectives related to spatial orientation by statistical analysis. Further, it analyzes the logic and application of collineation measurement in constructing the Imperial Citadel of Thang Long. The results show that Vietnamese designers used Tàn Viên Mountain as a component of Thang Long city by collineating the twomountain peaks to the west. Tàn Viên Mountain and the highlands extending eastward fromit are used as the key to establishing the position of the Imperial Citadel, setting the spatial structure of human settlements, and the development of city space. The location, layout, and formof important buildings in the Imperial Citadel are also closely related to the surrounding landscape within 50 km.     

隧洞开挖典型掏槽设计方法

针对目前隧洞开挖爆破施工中缺少具体、详细的掏槽设计方法的现状,提出了最常用的2种典型掏槽方式,并详细论述了其设计方法。这些掏槽方式及设计方法均在实际施工中得到了推广应用,并且取得了良好的爆破效果。实际应用表明:这些典型掏槽方式及设计方法能有效提高硬质岩石开挖的钻孔利用率,能将钻孔利用率提高到98%～100%,实现掌子面基本无残孔,从而有效提高单循环进尺,加快开挖进度,降低开挖成本。