Responses of microbial activities and soil physical-chemical properties to the successional process of biological soil crusts in the Gurbantunggut Desert,Xinjiang

Biological soil crusts （BSCs） are capable of modifying nutrient availability to favor the establishment of biogeochemical cycles. Microbial activities serve as critical roles for both carbon and nutrient transformation in BSCs. However, little is known about microbial activities and physical-chemical properties of BSCs in the Gurbantunggut Desert, Xinjiang, China. In the present research, a sampling line with 1-m wide and 20-m long was set up in each of five typical interdune areas selected randomly in the Gurbantunggut Desert. Within each sampling line, samples of bare sand sheet, algal crusts, lichen crusts and moss crusts were randomly collected at the depth of 0-2 cm. Varia- tions of microalgal biomass, microbial biomass, enzyme activities and soil physical-chemical properties in different succession of BSCs were analyzed. The relationships between microalgal biomass, microbial biomass, enzymatic activities and soil physical-chemical properties were explored by stepwise regression. Our results indicate that micro- algal biomass, microbial biomass and most of enzyme activities increased as the BSCs developed and their highest values occurred in lichen or moss crusts. Except for total K, the contents of most soil nutrients （organic C, total N, total P, available N, available P and available K） were the lowest in the bare sand sheet and significantly increased with the BSCs development, reaching their highest values in moss crusts. However, pH values significantly decreased as the BSCs developed. Significant and positive correlations were observed between chlorophyll a and microbial biomass C. Total P and N were positively associated with chlorophyll a and microbial biomass C, whereas there was a significant and negative correlation between microbial biomass and available P. The growth of cyanobacteria and microorganism contributed C and N in the soil, which offered substrates for enzyme activities thus increasing enzyme activities. Probably, improvement in enzyme activities increased soil fertility and promoted the growth of cyanobacteria, eukary- otic algae and heterotrophic microorganism, with the accelerating succession of BSCs. The present research found that microalgal-microbial biomass and enzyme activities played important roles on the contents of nutrients in the successional stages of BSCs and helped us to understand developmental mechanism in the succession of BSCs.

Calcium sulfate whisker prepared by flue gas desulfurization gypsum:A physical–chemical coupling production process

In this paper,the solid waste desulfurization gypsum produced by coal-fired power plants was used as a raw material to prepare calcium sulfate whiskers with high application prospects.Calcium sulfate whiskers with uniform morphology and high aspect ratio can be prepared by hydrothermal method in sulfuric acid solution.A new process of desulfurization gypsum activated by high-energy grinding to reduce the reaction temperature and sulfuric acid concentration was developed.Through the comparison of product morphology,the best grinding time was determined to be 3.5 h.The mechanism of desulfurization gypsum through physical–chemical coupling to reduce energy consumption was clarified.The activation of desulfurization gypsum by grinding and the acidic environment provided by the sulfuric acid solution made the calcium sulfate solution reached rapid saturation and accelerated the nucleation rate.By calculating the conversion and crystallization rate of calcium sulfate whiskers,it was found that there were obvious"autocatalytic"kinetic characteristics during the crystallization process.

Diagnosis of Physical and Biological Controls on Phytoplankton Distribution in the Sargasso Sea

The linkage between physical and biological processes is studied by applying a one-dimensional physical-biological coupled model to the Sargasso Sea. The physical model is the Princeton Ocean Model and the biological model is a five-component system including phytoplankton, zooplankton, nitrate, ammonium, and detritus. The coupling between the physical and biological model is accomplished through vertical mixing which is parameterized by the level 2.5 Mellor and Yamada turbulence closure scheme. The coupled model investigates the annual cycle of ecosystem production and the response to external forcing, such as heat flux, wind stress, and surface salinity, and the relative importance of physical processes in affecting the ecosystem. Sensitivity experiments are also carried out, which provide information on how the model bio-chemical parameters affect the biological system. The computed seasonal cycles compare reasonably well with the observations of the Bermuda Atlantic Time-series Study(BATS). The spring bloom of phytoplankton occurs in March and April, right after the weakening of the winter mixing and before the establishment of the summer stratification. The bloom of zooplankton occurs about two weeks after the bloom of phytoplankton. The sensitivity experiments show that zooplankton is more sensitive to the variations of biochemical parameters than phytoplankton.

不同发酵剂对发酵牛肉品质、风味特性和安全性的影响

牛肉富含蛋白质、脂肪含量低,深受消费者喜爱,然而其难咀嚼、附加值低。为提高牛肉的口感风味,研究本单位的3株专利菌株——W9-3罗伊氏乳杆菌、M3-16副干酪乳杆菌和MY4马克斯克鲁维酵母制备的单菌和复配发酵剂对牛肉理化、感官品质、生物胺形成和挥发性风味的影响。结果表明,与未发酵和自然发酵的牛肉相比,添加发酵剂可降低牛肉的pH(均小于5.5)、水分活度(降低0.6%~4.1%)、TBA值和羰基值,抑制组胺、色胺、酪胺和丁二胺等生物胺的形成,提升熟化牛肉的亮度和弹性,降低硬度、黏着性、咀嚼性和黏聚性。其中复配组优于单菌组。利用SPME-GC-MS方法从焙烤发酵牛肉中鉴定出86种挥发性化合物,其相对含量和主成分分析结果表明,用发酵剂发酵的烤牛肉的风味物质与未发酵和自然发酵相比形成多种新的醇、醛和酮类。感官评价表明,使用发酵剂能在一定程度上提高牛肉的组织形态、外观色泽、气味和口感。尤其是复配发酵剂可改善发酵牛肉品质,提升风味,抑制生物胺。本文为牛肉发酵工艺优化提供理论依据。

壳聚糖的改性研究进展及其应用

壳聚糖被发现以来存在极大的优势,是一种可被修饰的自然生物聚合物。因为其具有丰富的官能团,在功能材料中被广泛应用。简要综述壳聚糖及其改性材料的最新进展,重点详述其物理、化学和生物等改性方法并得到功能材料。其改性功能材料在水处理、食品加工、制药/生物医学、纺织和农业等领域展示出优异的应用性能。最后,作了简短总结展望,其改性研究和应用仍有更大的探索前景。

黑木耳黑色素研究进展

黑木耳(Auricularia heimuer)黑色素是天然无毒的生物色素,具有抗辐射、抗氧化和保护肝脏等作用,被广泛应用于食品、医药和化妆品等领域。笔者综述了黑木耳黑色素提取和纯化方法、结构表征、理化性质以及生物学功能,展望了其在食品、医药和化妆品领域的应用,并阐述了当前存在问题及今后研究方向,以期为黑木耳黑色素研究和应用提供参考。

稀土元素的生物学功能及其在动物生产中的应用

稀土元素是一类具有独特理化性质的金属元素。大量研究表明,稀土元素可通过增强酶活性、抑菌作用、调节免疫功能、改善胃肠道微生物区系等方式,参与动物代谢和生理调控,最终改善动物的生产性能和健康状况等。由于稀土元素的高化学活性,所以其通常以有机或无机形式应用到生产实践中。本文综述了稀土元素的理化性质、生物学功能以及不同形式稀土元素在动物生产中的应用情况,并对未来稀土元素作为饲料添加剂的应用做出展望,以期为利用稀土元素作为新型饲料添加剂配制饲粮提供全面的理论参考,并为饲粮补饲稀土元素在动物实际生产过程中的应用提供广泛的实践参考。

二氧化碳资源化利用研究进展

温室气体的大量排放导致的气温升高、冰川融化、极端天气等气候环境问题日益严重。“碳达峰、碳中和”背景下开展二氧化碳捕集与资源化利用研究是改善生态环境、优化能源结构、推动国内产业升级和构建绿色循环经济的有效途径。分别从物理利用、化学利用及生物利用的角度综述了当前二氧化碳资源化利用研究进展,解析了主要资源转化技术特点及优势与不足。重点阐述了二氧化碳加氢催化、高温化学链裂解、光催化等资源转化技术特点及影响机制,归纳了催化剂在不同体系中的作用机理,展望了具有应用前景的二氧化碳资源化利用途径。

植物精油的生物学活性及其在仔猪生产上的应用

自抗生素在养殖业中的应用受到限制以来,植物精油作为绿色、高效、安全的抗生素替代品在提高动物生产性能和养殖效益等方面受到越来越多的关注,目前已被广泛应用于动物生产中。断奶仔猪的肠道发育不完全,在饲养过程中受多种因素的影响经常出现腹泻现象,影响生产性能。植物精油具有抑菌、抗氧化、抗炎等特性,能够有效改善断奶仔猪的肠道菌群结构、促进肠道健康发育、提高仔猪生长速度。本文从植物精油的理化特性、生物学活性及其在仔猪生产上的应用进行综述。

黄曲霉毒素B1降解产物及降解安全性评价研究进展

为推动黄曲霉毒素B_(1)(AFB_(1))降解技术的应用,寻求高效、快捷、安全的AFB_(1)降解技术,促进食品中黄曲霉毒素的防治工作,对AFB_(1)降解技术(物理降解技术、化学降解技术、生物降解技术)产生的降解产物以及降解后食品安全性评价研究的现状进行了论述,概括了降解技术的不足之处,并对降解技术的发展趋势进行展望。物理降解技术较适合大规模应用,但微波、脉冲电场、低温等离子体等技术仍处于研发阶段,无法确保该技术的安全性与可靠性。化学降解技术的研究比较常见,但存在食品感官品质变差,营养成分损失或破坏,易引入新的化学残留等不足。生物降解技术具有性质温和,不造成食品中营养成分大量损失且绿色环保等优点,但仍处于实验室研发阶段。在今后的研究中,应加强寻找新型纳米材料发展光降解技术、或各种技术联合使用、或利用基因工程联合酶法脱毒等新型技术,同时应更深入地研究降解机制、降解产物、降解路径以及降解产物的安全性。

苯胺类废水处理技术的研究进展

概述了苯胺的结构,苯胺的物理与化学性质,详述了关于苯胺类废水的物理、化学、生物处理方法,扩展了苯胺类废水的耦合处理法。同时展望了苯胺类废水处理技术的前景,提出了对于苯胺类废水处理技术的新思路。

木质纤维素预处理技术研究现状与展望

木质纤维素是自然界中最丰富的可再生资源,可用于生产燃料乙醇、生物柴油等能源产品,也是制备化学品和造纸的主要原料。木质纤维素主要由纤维素、半纤维素和木质素组成,复杂的化学结构限制了其高效利用,故必须对其进行预处理,去除木质素、半纤维素等不可溶物质,从而使其更易被酶水解成可发酵的糖,进而提高木质纤维素的降解转化率。预处理技术可以改变木质纤维原料的内部结构和表面性质,为后续的酶解糖化创造良好条件。从物理、化学、生物、联合处理等4个方面全面综述了不同木质纤维素预处理技术的研究现状,总结了其预处理效果和优缺点,并展望了其未来的研究方向,旨在为木质纤维素生物质降解利用研究提供参考。

Temporal and Spatial Seasonal Variations in Quality of Gravity Flow Water in Kyanamira Sub-County, Kabale District, Uganda

The study was designed to investigate temporal and spatial seasonal variations in quality properties of gravity flow water samples collected from Kigata, Kacuro, Kihanga, Kitibya and Kanjobe located in Kyanamira Sub-County, Kabale District, Uganda. Physical, chemical and biological parameters such as pH, temperature, dissolved oxygen, total dissolved solids, electrical conductivity, turbidity, colour and total suspended solids, total hardness, total alkalinity, chloride, fluoride, nitrates-N, nitrites-N, ammonium-N, sulphates, total phosphate, sodium, calcium, magnesium and some heavy metals were analyzed. Total iron, lead, chromium, copper, zinc, manganese and cadmium were analyzed by atomic absorption spectrometry. Two of the basic biological parameters for drinking water such as faecal coliforms and salmonella were analyzed by incubation followed by counting colony forming units (CFUs). Statistical presentations of data including cluster analysis, dendrograms and principal component analysis were used with the assistance of PAST software. Temperature, pH, TDS dissolved oxygen, cations, anions (chemical parameters) and salmonella, faecal coliforms were the major contributing parameters to gravity flow water’s quality variations during both seasons. Values of pH ranged between 3.78 and 4.84 from March to August in all study sites and they were consistently below the WHO permissible pH range of 6.5 - 8.5. Total suspended solids ranged between 0.66 and 2.17 mg·L-1 and were above the recommended WHO limit of zero value in all study sites. Salmonella and faecal coliforms colonies were present in scaring numbers in the wet season. In March, salmonella counts at Kacuro (14 CFU) and Kanjobe (128 CFU) while faecal coliforms counts at Kacuro (515 CFU) and Kanjobe (228 CFU). The findings of this study call for special attention when using gravity flow water.

玉米秸秆生物反应堆替代化肥对土壤理化性质和西瓜产量与品质的影响

2018-2020年通过设置传统施肥处理和玉米秸秆生物反应堆部分替代化肥处理,以期实现土壤理化性质与西瓜产量品质协同提升。结果表明,秸秆生物反应堆技术较常规栽培能够在减少化肥(15-15-15)用量375 kg·hm^(-2),且不施用农药的基础上,改善土壤理化性质、提高西瓜产量与品质。秸秆生物反应堆部分替代化肥处理的土壤有机质含量较试验前持续提高,增幅18.8%,而传统施肥导致土壤有机质含量持续降低,降幅12.4%。同时,秸秆生物反应堆部分替代化肥处理能够增加碱解氮的供应,减少有效磷与速效钾的累积。与传统施肥处理相比,秸秆反应堆部分替代化肥处理能够显著提高西瓜产量,平均增产6.8%(6.6%~8.1%);2020年的西瓜蛋白质含量提高5.4%、可溶性固形物含量提高17.9%、维生素C含量提高7.5%。基于以上结果,安丘市西瓜产区应用秸秆生物反应堆技术对西瓜的优质可持续生产具有重要意义。

油田聚合物驱污水处理技术研究进展

油田聚合物驱污水的高效处理与回注是油田开采的重要过程。本文对油田聚合物驱污水水质特性进行概述,并简要介绍了物理法、化学法和生物法的发展历程及各种方法的优势,阐述了物理化学法的研究现状,并对油田聚合物驱采出水的未来发展方向进行了展望,对油田的高效开发具有重要意义。

Interaction between B-Doped C60 Fullerene and Glycine Amino Acid from First-Principles Simulation

The possibility of formation of complexes between glycine and boron doped C60 （C59B） fullerene is investigated and compared with that of C60 fullerene by using the density functional theory calculations. It has been found that the binding of glycine to C59B generated the most stable complexes via its carbonyl oxygen active site, with a binding energy of-37.89 kcal/mol, while the glycine molecule prefers to bind to the pure C60 cage via its amino nitrogen active site, consistent with the recent experimental and theoretical studies. We have also tested the stability of the most stable Gly-C59B complex with ab initio molecular dynamics simulation, carried out at room temperature. These indicate that the B-doped C60 fullerenes seem to be more suitable materials for bindings to proteins than pure C60 fullerenes.

含油废水处理技术研究进展

石油、餐饮、煤化工行业的发展,产生了大量的含油废水,对水体、土壤造成严重污染。含油废水排入水体、土壤后,在水体表面、土壤空隙形成油膜,不利于水生生物、农作物的生长,因此含油废水的治理不容忽视。国内外学者针对油类物质的处理分别在物理、化学、生物方面进行研究,提出了气浮法、膜分离法、电解法、厌氧生物处理等方法,对含油废水处理工艺不断完善。

平菇培养料发酵后熟化栽培技术开发与应用

为探索平菇发酵料最佳处理方式,对发酵料进行不同次数翻堆后将部分发酵料于70℃或80℃进行熟化处理,并与未熟化发酵料进行对比。测定不同翻堆次数后发酵料的理化性质(含水量、pH)、微生物(真菌、细菌、放线菌)变化趋势、干物质损耗情况。比较不同翻堆次数发酵料及熟化处理料对平菇菌丝生长及出菇的影响。结果表明,发酵料第1次翻堆时料中细菌、真菌、放线菌数量达到峰值,第2次翻堆后数量呈下降趋势。发酵料分别经70℃和80℃熟化处理后,料中微生物菌落明显减少。其中,70℃熟化后嗜热真菌、细菌、放线菌均少量存在;经过80℃熟化后发酵料中真菌几乎不可见,但仍存在嗜热放线菌。研究结果表明,发酵料在经过2次翻堆即可达到标准,再经过80℃熟化处理后效果更佳,表现为平菇菌丝生长较快、生物学效率较高。

矿物加工工程中浸出技术的运用与实践分析

矿物在人类社会发展中发挥了重要作用。矿物与人们的生活有着紧密的联系,被各个行业广泛应用。科学技术的不断发展助力了矿物加工行业的发展。在矿物加工工程中运用浸出技术,可以有效提升矿物加工工程质量,向人们提供更加优质的矿物材料。对矿物浸出技术的特点进行了简要分析,讨论了矿物加工工程中浸出技术的运用与实践要点,以供参考。