响应面优化冷冻杏果低温压榨出汁率、理化指标及挥发性成分分析

杏果在冷冻过程中，由于冰晶的生长造成的机械作用使细胞壁、细胞膜等组织结构破坏，加速细胞汁液的溶出。在单因素（冷冻温度、压强大小、压榨时间）试验考察的基础上，以出汁率为响应值，通过响应面法对条件进行优化，测定其杏汁的理化指标，经固相微萃取（SPME）技术提取，且采用气相色谱-质谱法（GC-MS）对冷冻杏果低温压榨杏汁的挥发性物质进行分析和鉴定。结果表明：冷冻温度为（-17±1）℃、压强大小为13.71 kPa、压榨时间为3.25 h时杏果出汁率达到最大为61.85%；杏汁中总糖含量为 75.01 mg/mL，还原糖含量为26.33 mg/mL，可溶性固形物为15 °Brix，pH值为3.58，可滴定酸含量为1.79%，可溶性蛋白质含量为23.97 mg/100 mL，可溶性果胶含量为16.72 mg/mL，澄清度为86.97%；杏汁中共检测出63种挥发性成分，包括醇类、酮类、烯烃类、芳香烃类、酯类和其他类各13、13、13、8、7和9种，其中芳樟醇、松油醇等挥发性物质的相对含量较高，其具有清甜的花香和果香，具有鲜杏的特征香气。     

李光杏干制过程护色剂优化及非酶褐变分析

为了改善李光杏传统干制过程中的色泽及探讨非酶褐变有关主要物质变化规律.以新疆李光杏为研究试材,分析研究柠檬酸、植酸、L-半胱氨酸对李光杏干制品色泽的影响,在单因素试验的基础上,以L*值为指标,通过Box-Benhnken试验,确定最适浸渍浓度,研究了复合护色剂处理的李光杏干制过程中抗坏血酸、总酚、游离氨基酸、还原糖含量...     

Vacancy defects reducing the accuracy and reliability of NTC sensors

The negative temperature coefficient (NTC) thermal sensor has received much attention for temperature sensing, which aims to achieve accurate temperature measurement by using the electrical signal generated by its temperature change. The perovskite (1-x)CaMn_0.05Zr_0.95O₃-xCaMnO₃ (x = 0, 0.1, and 0.2) composite ceramics were reported for the first time. Furthermore, their structure, microscopic morphology, and device performance were systematically evaluated. It was revealed that the sensor performance could be tuned by controlling the CaMnO₃ ratio in the low resistance phase. The phase structure and crystal structures (cell volume and cell parameters a, b, and c) of the composite ceramics were defined using x-ray diffraction (XRD) refinement. Scanning electron microscopy (SEM)/Mapping revealed dense and uniform micromorphology. The ln(ρ) and 1000/T were quite linear, and the aging drift rate was as low as 1.89% after aging at 900 °C for 600 h. Importantly, a novel double hopping mechanism and a cation vacancy defect diffusion model were proposed to reveal the electron transport mechanism in the sensor lattice and elaborate the physical mechanism of the effect of cation vacancy defects on sensor resistance drift. In conclusion, this study prepared an NTC thermal sensor with ultra-high stability in a high temperature environment by rational design, providing a fresh idea for subsequently developing a high temperature NTC sensor.     

养殖淡水鱼源ST283型B群链球菌引发食物相关侵袭性疾病风险及防控

B群链球菌存在于多种动物中，是能感染人类的一种重要条件致病菌，主要引起孕产妇及新生儿多种侵袭性疾病。ST283是近年来在东南亚地区的养殖淡水鱼中出现的一种B群链球菌型别，由于其可引起人类食物相关侵袭性疾病而受到广泛关注。我国作为淡水鱼养殖和食用大国，虽内陆尚无相关病例报道，仍需引起重视。本文就各国现有资料对ST283型B群链球菌进行阐述，为我国制定B群链球菌监测及评估标准提供参考。     

含水量对新疆鲜食核桃贮藏期黄曲霉生长及黄曲霉毒素M1积累的影响

目的:提高新疆鲜食核桃的贮藏安全性。方法:以新疆“新2”薄皮核桃为材料，无菌水接种为对照组，黄曲霉菌接种为试验组，将从自然霉变核桃上分离纯化出的黄曲霉菌人工接种至不同含水量(10%,15%,20%,25%,30%)的新疆薄皮鲜食核桃上，探究黄曲霉菌生长量及产毒变化情况。结果:最适宜黄曲霉菌生长繁殖并分泌黄曲霉毒素M₁的核桃含水量为15%;随着核桃含水量的升高，黄曲霉菌生长量呈先上升后下降趋势，但各含水量之间的生长量各不相同，且黄曲霉菌生长量与产生黄曲霉毒素M₁的量成正比。结论:原料的含水量与黄曲霉菌生长量及产生黄曲霉毒素M₁的量有着密切的关系。     

A novel pico-hydro power (PHP)-Microbial electrolysis cell (MEC) coupled system for sustainable hydrogen production during palm oil mill effluent (POME) wastewater treatment

Due to accelerating global efforts toward decarbonization, a clean hydrogen (H₂) producing technology, Microbial Electrolysis Cell (MEC), has garnered considerable attention. However, MEC's external energy requirement has raised concerns about its sustainability, scalability and application costs. The objective of this research was to build a renewable energy generating system for MECs' performance enhancement during the treatment of Palm oil mill effluent (POME). A novel integration of a pico-hydro-power generator (PHP) with single-chambered MECs exceptionally improved its performance. The performance boost was observed as 1.16 m³-H₂/m³d H₂ and 113 A/m³current production in concomitant with 73% organics removal from Palm Oil Mill Effluent (POME) wastewater, which is higher than the previous single-chambered MECs studies. 78% H₂ recovery r_cat (H₂) along with 57% coulombic efficiency (CE) corroborated the removal of a high percentage of electrons from POME organic materials to generate >96% pure H₂. The MEC nourished POME wastewater degrading communities while stimulating growth of electroactive Geobacter in the anodic biofilm which produced H₂. The overall H₂ recovery, COD removal rate and energy efficiency of PHP-MEC are superior than other MECs powered by other external renewable energy sources reported to date. The PHP-MEC prototype paves the path of scale up studies to build a renewable energy dependent future.     

Growth,microstructure and magnetic properties of bixbyite structure ScFeO3: A comparative study between bulk and thin film

The growth, microstructure and magnetic property of both bulk and thin film types of ScFeO₃ are studied. Results show that the mono-phase bixbyite structure bulk ScFeO₃ can be obtained with sintering temperature above 1400 °C. The bulk ScFeO₃ shows dominant antiferromagnetic property with an antiferromagnetic Neel temperature T_N about -26 K. The epitaxial type of ScFeO₃ thin film with bixbyite structure can be well grown on the SrTiO₃(111) substrate. The magnetic property of ScFeO₃ thin film is significantly different from that of bulk material which shows notable room temperature ferromagnetism with a saturation field below 0.4 T. The saturation magnetization M_S, remanent magnetization M_r, coercivity H_c and of ScFeO₃ film increase with decreasing temperature with maximum values of M_S = 5.1 emu/cc, M_r = 1.5 emu/cc, and H_c = 29 mT at 5 K. The ferromagnetism of ScFeO₃ thin film should be caused by the interface mismatch strain at film/substrate interface. This further proves that ferromagnetism of ScFeO₃ can be stabilized with microstructure engineering including strain, which enable multifunctional properties of this material.     

不同解冻方式对哈萨克羊肉脂质及蛋白质氧化的影响

为探讨不同解冻方式对羊肉脂质及蛋白质氧化的影响,以哈萨克羊半膜肌及背最长肌为研究对象,测定其脂质、蛋白质氧化指标,结合SDS-PAGE观察不同部位肌肉蛋白质降解情况。结果表明:冷藏解冻后羊半膜肌及背最长肌过氧化值为3.33、4.58mmol·kg-1,丙二醛质量比为0.16、0.24mg·100g-1,羰基质量摩尔浓度为3.59、4.62nmol·mg-1,巯基质量摩尔浓度为41.26、38.73nmol·mg-1,疏水键质量为64.72、75.25μg；静水解冻后2种肌肉过氧化值为4.91、5.79mmol·kg-1,巯基质量摩尔浓度为38.40、33.40nmol·mg-1、全蛋白溶解度为184.50、171.90mg·g-1,肌浆蛋白溶解度为69.07、60.77mg·g-1,肌原蛋白溶解度为115.43、111.13mg·g-1；而空气解冻后2种肌肉的过氧化值为7.00、7.71mmol·kg-1,丙二醛质量比为0.33、0.44mg·100g-1,羰基质量摩尔浓度为13.19、14.06nmol·mg-1,巯基质量摩尔浓度为17.46、12.56nmol·mg-1,疏水键质量为75.20、82.47μg。5种解冻方式羊肉氧化程度由低至高依次为冷藏解冻、静水解冻、超声波解冻、微波解冻、空气解冻(P<0.05)。SDS-PAGE结果表明:羊肉经冻结-解冻后蛋白质均存在不同程度的降解,超声波解冻对背最长肌蛋白质降解影响较大。研究表明:冷藏解冻及静水解冻后羊肉氧化程度较低,具有较好的品质,更适于冻结羊肉的解冻。     

Influence of B2O3 on viscosity and structure of the CaO–Al2O3-waste electrolyte (WE) based melt

The fluorides contained waste electrolyte (WE) from the electrolytic aluminum industry can be used as a substitution of fluorite (CaF₂) in the newly designed mold flux. In this study, the influence of B₂O₃ on viscosity and structure of CaO–Al₂O₃-WE based melt was investigated. Results show that the viscosity of mold flux melt decreases with both increasing temperature and B₂O₃ content. The apparent activation energy (E_a) also reduces from 78.96 ± 1.75 to 55.26 ± 2.79 kJ/mol with the addition of B₂O₃ from 0 to 7 wt%. The analyses of fourier transform infrared (FTIR) and Raman spectroscopies suggest that the lower symmetry of the original aluminate and silicate structure due to the insertion of [BO₄]-tetrahedral and [BO₃]-triangular, and the formation of more non-bridging oxygen (O⁻) and 2D structural units in the network with the addition of B₂O₃, deceases the viscosity and E_a of the CaO–Al₂O₃-WE Based Melt.     

折叠交叉立方体的 2-限制性边通度

$h$-限制性边连通度是衡量大型互连网络可靠性和容错性的一个重要参数。设 $G$ 是连通图且 $h$ 是非负整数，如果 $G$ 中存在某种边子集，使得 $G$ 删除这种边子集后得到的图不连通并且每个分支中点的度至少是 $h$，则所有这种边子集中基数最小的边子集的基数称为图 $G$ 的 $h$-限制性边连通度。$n$-维折叠交叉立方体是由 $n$-维交叉立方体增加一些补边后所得。对于此类问题，首先利用 $2$-限制性边连通度作为可靠性的重要度量，对折叠交叉立方体网络的可靠性进行分析，然后得到折叠交叉立方体的 $2$-限制性边连通度，最后证明并确定 $n$-维折叠交叉立方体的 $2$-限制性边连通度等于 $4n-4 (n\geq 4)$。这个结果意味着，为了使 $n$-维折叠交叉立方体不连通且每个分支中没有度数小于 2 的点，至少应有 $4n-4$ 条边同时发生故障。