Effects of fumaric acid supplementation on methane production and rumen fermentation in goats fed diets varying in forage and concentrate particle size

Background: In rumen fermentation, fumaric acid(FA) could competitively utilize hydrogen with methanogenesis to enhance propionate production and suppress methane emission, but both effects were diet-dependent. This study aimed to explore the effects of FA supplementation on methanogenesis and rumen fermentation in goats fed diets varying in forage and concentrate particle size.Methods: Four rumen-cannulated goats were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments: low or high ratio of forage particle size: concentrate particle size(Fps:Cps), without or with FA supplementation(24 g/d). Fps:Cps was higher in the diet with chopped alfalfa hay plus ground corn than in that with ground alfalfa hay plus crushed corn.Results: Both increasing dietary Fps:Cps and FA supplementation shifted ruminal volatile fatty acid(VFA) patterns toward more propionate and less acetate in goats. An interaction between dietary Fps:Cps and FA supplementation was observed for the ratio of acetate to propionate(A:P), which was more predominant when FA was supplemented in the low-Fps:Cps diet. Methane production was reduced by FA, and the reduction was larger in the low-Fps:Cps diet(31.72%) than in the high-Fps:Cps diet(17.91%). Fumaric acid decreased ruminal total VFA concentration and increased ruminal p H. No difference was found in ruminal DM degradation of concentrate or alfalfa hay by dietary Fps:Cps or FA. Goats presented a lower ruminal methanogen abundance with FA supplementation and a higher B. fibrisolvens abundance with high dietary Fps:Cps.Conclusions: Adjusting dietary Fps:Cps is an alternative dietary model for studying diet-dependent effects without changing dietary chemical composition. Fumaric acid supplementation in the low-Fps:Cps diet showed greater responses in methane mitigation and propionate increase.

Research and Implementation of Decreasing the Acetic Acid Consumption in Purified Terephthalic Acid Solvent System

Decreasing the acetic acid consumption in purified terephthalic acid （PTA） solvent system has become a hot issue with common concern. In accordance with the technical features, the electrical conductivity is in direct proportion to the acetic acid content. General regression neural network （GRNN） is used to establish the model of electrical conductivity on the basis of mechanism analysis, and then particle swarm optimization （PSO） algorithm with the improvement of inertia weight and population diversity is proposed to regulate the operating conditions. Thus, the method of decreasing the acid loss is derived and applied to PTA solvent system in a chemical plant. Cases studies show that the precision of modeling and optimization are higher. The results also provide the optimal operating conditions, which decrease the cost and improve the profit.

Scalable synthesis of lipid nanoparticles for nucleic acid drug delivery using an isometric channel-size enlarging strategy

Lipid nanoparticles(LNPs)have emerged as highly effective delivery systems for nucleic acid-based therapeutics.However,the broad clinical translation of LNP-based drugs is hampered by the lack of robust and scalable synthesis techniques that can consistently produce formulations from early development to clinical application.In this work,we proposed a method to achieve scalable synthesis of LNPs by scaling inertial microfluidic mixers isometrically in three dimensions.Moreover,a theoretical predictive method,which controls the mixing time to be equal across different chips,is developed to ensure consistent particle size and size distribution of the synthesized LNPs.LNPs loaded with small interfering RNA(siRNA)were synthesized at different flow rates,exhibiting consistent physical properties,including particle size,size distribution and encapsulation efficiency.This work provides a practical approach for scalable synthesis of LNPs consistently,offering the potential to accelerate the transition of nucleic acid drug development into clinical application.

Effects of particle size and particle interactions on scheelite flotation

Effects of size distribution (particle size and content of fine fraction (<10μm)) on scheelite flotation were studied using flotation tests and theoretical calculations. The results show that particle size influences the scheelite recovery and the performance of combined reagents. The scheelite recovery is lowered by adding fine particles (<10μm) into the pulp containing coarse particles. Extended DLVO (EDLVO) theory confirms that the fine fractions (<10μm) could interface with the coarse fractions. The interaction energy and fluid forces are relative to the particle size, which might explain why the fine fractions influence the scheelite flotation. The highest recovery of scheelite using combined reagents as collector and optimum ratio of combined reagents were determined by scheelite particle size and reagent performance. However, the optimum adding order was only determined by reagent performance, which has nothing to do with particle size.

Influences of Organic Solvents on Particle Size and Drug-loading Efficiency for 5-Fluorouracil Poly(lactic acid)Nanoparticles

The objective of this study was to investigate the influences of organic solvents on particle size, drug content, loading efficiency and yield for 5 Fluorouracil Poly(lactic acid) nanoparticles . The 5 Fluorouracil was entrapped into poly(lactic acid)(PLA) nanoparticles using a water in oil in water solvent evaporation technique. During the preparation process, ethyl acetate and acetone were used as organic solvents since they are less toxic than the more commonly used dichloromethane. The effect of the three solvents on particle size, drug content, loading efficiency and yield of nanopartcles was compared. When the solvent of the oil phase was acetone, the highest drug content, smallest particle size and lowest yield were obtained for the PLA nanoparticles.

Storage Stability of Alpha-Lipoic Acid-loaded Lipid Nanoparticles

Alpha-lipoic acid-loaded lipid nanoparticles(ALA-LNs) were prepared by high pressure homogenization method.The influences of storage conditions such as time and temperature on the physical and chemical storage stability of ALA-LNs were studied in details.The stability was evaluated by particle size and polydispersity index,morphology of ALA-LNs,and capacity of ALA loading.The dilution and pH stability of ALA-LNs suspensions were also studied.After three months storage,the mean size of ALA-LNs at 4 and 40 ℃ was increased by 2.68% and 3.62% compared with the original size,respectively.ALA-LNs stored at 40 ℃ had ellipsoid shape and the mean size was about 152 nm(SD=23.6).The loading capacity of ALA at 40 ℃ was much higher than those stored at other two temperatures.The good dilution and pH stability were also demonstrated.The sample had good fluidity even at 4 ℃.

Influence of Block Copolymer on Formation and Acid Resistant Properties of Hybrid CaCO_3 Particles

Block copolymer polystyrene-b-poly（acrylic acid）（PS-b-PAA） was used as structural template for the synthesis of CaCO3 microparticles. Through this procedure, acid resistant hybrid CaCO3 micro- spheres were obtained. Acid resistant properties of this type of hybrid CaCO3 were studied. Size measurement shows that the acid resistant properties of the hybrid particles are different in different solutions, such as HCl, EDTA, and H2SO4 solutions.

Extraction of aluminium as aluminium sulphate from thermal power plant fly ashes

Valuable metal extraction technology from thermal power plant fly ash is limited.In the present study,aluminium is extracted from fly ash as highly pure aluminium sulphate(>99.0%)by leaching with sulphuric acid,followed by pre-concentration and successive crystallization.Two types of fly ashes from different sources,i.e.,Talcher Thermal Power Station(TTPS)and Vedanta Aluminium Company Limited(VAL)were chosen for comparative study on the extraction of aluminium as aluminium sulphate.The product is characterized by powder X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FTIR)and thermogravimetric analysis(TGA).Purity of aluminium sulphate was also investigated by inductively coupled plasma?optical emission spectrometry(ICP?OES).The extraction efficiency of aluminium depends on the varied solid-to-liquid ratio(fly ash:18mol/L H2SO4,g/mL)and particle size of fly ashes.Physico-chemical analysis indicates that the obtained product is Al2(SO4)3·18H2O,having low iron content(0.08%).

Nanonization of Niflumic Acid by Co-Grinding

The aim of this study was to produce niflumic acid nanoparticles without using an organic solvent, in order to achieve an increased rate of dissolution of the final products. Co-grinding with excipients was used to decrease the particle size. Poloxamer 188 (P) and mannitol (M) applied as co-grinding materials stabilized the system, preventing aggregation of the nanocrystals. The morphology and particle size distribution of the products were visualized by using scanning electron microscopy and laser diffraction. The crystalline states of the samples were investigated by differential scanning calorimetry and X-ray powder diffraction. The rate of dissolution of niflumic acid was measured with a paddle method from simulated media. It was concluded that the particles produced were in the nanometer range (the mean particle size was ~250 nm) and the nanoparticles maintained their crystallinity during the process. The rate of dissolution of the coground sample was significantly improved.

聚酯类颗粒暂堵剂的降解规律及水解机理

考察了盐酸和NaOH水溶液质量浓度、温度对聚乳酸(PLA)、聚乙交酯(PGA)、聚己二酸-对苯二甲酸丁二醇酯(PBAT)降解性能的影响,通过FTIR、XRD、SEM探究了聚酯类颗粒作为酸压暂堵剂的降解规律和水解机理,并对其封堵性能进行了评价。结果表明,盐酸或NaOH水溶液质量浓度越大,温度越高,PLA、PGA、PBAT完全降解时间越短,在相同质量浓度下,它们在NaOH水溶液中降解比在盐酸中更快;同样条件下,降解速率由大到小的3种聚酯类颗粒暂堵剂排序为PGA>PLA>PBAT。聚酯类颗粒暂堵剂在降解初期,酯基开始水解,颗粒表面出现孔洞,颗粒体积略微减小;随着降解的进行,水解优先发生在无定形区,结晶度增大,羰基指数减小,羟基指数增大,颗粒表面孔洞增多,体积进一步缩小;降解后期,结晶区开始水解,结晶度减小,聚合物分子链大量断裂,直至完全降解。封堵性能(承压能力)由大到小排序为PLA>PGA>PBAT,聚酯类颗粒暂堵剂与水的固液比(g∶L)为150∶1的PLA、PGA、PBAT突破压力分别为11.7、10.9、7.5 MPa;注入聚酯类颗粒暂堵剂的固液比越大,封堵层越致密,承压能力越强。

颗粒大小对蔬菜废弃物厌氧发酵过程的影响研究

蔬菜流通环节产生的大量蔬菜废弃物(即尾菜)亟需无害化处理,然而现有尾菜规模化处理采用的“破碎+压榨+厌氧/好氧”处理工艺易出现厌氧发酵酸化问题。为了破解此问题,在分析现有尾菜规模化处理工艺中发现破碎过细是造成厌氧发酵酸化的主要原因,因以尾菜为主要原料的厌氧发酵,常因为其水解过快,体系内有机酸过度积累出现酸化现象,导致产气失败。为了进一步研究颗粒大小对尾菜厌氧发酵过程的影响,提高其能源利用率,文章选取白菜作为试验底物,比较了高有机负荷下不同颗粒大小白菜(2 cm见方小块、完整叶片、1/4棵)对产沼气性能的影响。结果表明:较小颗粒大小会导致出现酸化现象。颗粒大小为整片和1/4棵条件下累积产气量分别为68.1 L、69.2 L,发酵过程处于稳定状态;颗粒大小为2 cm小块试验组出现酸化产气停止,各基础指标出现停滞或累积现象。试验可为尾菜规模化快速处理提供数据参考。

MAM相对分子质量对PLA/PBAT/MAM共混物结构与性能的影响

通过熔融共混法制备聚乳酸/聚己二酸对苯二甲酸丁二酯/聚(甲基丙烯酸甲酯)-b-聚(丙烯酸丁酯)-b-聚(甲基丙烯酸甲酯)(PLA/PBAT/MAM)三元共混物,研究了MAM相对分子质量对PLA/PBAT/MAM三元共混物形态、结构和性能的影响。结果表明,添加MAM嵌段共聚物,能够有效改善PLA与PBAT的相容性,使共混物的玻璃化温度下降,结晶消失,使分散相粒子尺寸下降,分布更加均匀,提高共混物的冲击强度和断裂伸长率;MAM相对分子质量越大,共混物的冲击强度和断裂伸长率越大,分散相粒子尺寸越小,粒径分布越均匀。

椰子蛋白化学结构和热稳定性研究

目的研究椰子全粉中蛋白质的结构和热稳定性,为深度开发椰子蛋白资源提供理论基础。方法采用碱提酸沉法提取椰子全粉中蛋白质,酸水解法结合氨基酸自动分析仪测定氨基酸组成,利用傅里叶变换红外光谱法分析蛋白二级结构,热重分析仪分析蛋白热降解曲线,纳米粒度分析仪研究溶液中蛋白颗粒的Zeta电位和粒径大小。结果椰子蛋白含有18种氨基酸,富含精氨酸和谷氨酸,8种必需氨基酸含量丰富、比例合理,是营养良好的蛋白质来源。椰子蛋白的二级结构以稳定态的β-折叠为主,含量达44.18%,椰子蛋白降解起始温度273.12℃,峰值温度332.91℃,至最终实验设定温度790℃时仍有25.9%残余未热降解完全,60℃时椰子蛋白溶液Zeta电位和粒径与25℃无显著变化。结论椰子蛋白具有良好的营养价值和热稳定性,可为椰子蛋白资源的深度开发和广泛利用提供理论参考。

低品位氧化铜钴矿堆浸试验研究

对刚果(金)某低品位氧化铜钴矿资源进行了堆浸试验研究,考察了喷淋强度、喷淋酸度和矿石粒度对铜钴浸出率的影响。结果表明,喷淋酸度和喷淋强度对铜钴浸出速度和累计浸出率影响显著,而矿石粒度对浸出过程影响不大。确定了低品位氧化铜钴矿适宜的堆浸条件为:喷淋酸度20 g/L,喷淋强度15 L/(m^(2)·h),矿石粒度-40 mm。在此条件下,堆浸100 d,铜和钴累计浸出率分别可达90.89%和82.27%。

氢氟酸沉淀法制备松装密度适度的大颗粒无水氟化镨钕的研究

采用氢氟酸沉淀法制备无水氟化镨钕粉体,考察了草酸加入量、底水酸度、上清液循环利用次数、氢氟酸用量等条件对水合氟化镨钕晶体的形成和无水氟化镨钕粉体的形貌、粒度、松装密度、杂质等的影响。结果表明,优化的工艺条件为:草酸投入量为理论用量(RE^(3+)物质的量的1.5倍)的6%~10%,底水的酸度为1.6~2.0 mol/L,上清液循环利用次数≤3次,氢氟酸投入量为100%理论用量(RE^(3+)物质的量的3倍)。采用优化工艺条件制备的无水氟化镨钕中位粒径D_(50)可达到10~30μm,松装密度为0.7~0.8 g/cm^(3),非稀土杂质含量低,稀土收率达到99.81%。

聚乙二醇改性油酸的性能研究

为提高液压液的稳定性,保障液压支架跟机移架的可靠性,研究了4个厂家的油酸和其改性后的产物对液压液粒径的影响,通过气质联用分析各油酸的组成,采用醇胺和聚乙二醇分别对油酸进行改性,考察了改性油酸在水溶液中的润滑性、表面张力、pH值、电导率、Zeta电位和粒径,及不同配液浓度下,含改性油酸液压液的粒径。结果表明,在500 mg/L的人工硬水中,醇胺改性油酸产生沉淀,聚乙二醇改性油酸未产生沉淀;杂质含量较少的油酸,经聚乙二醇改性后,表面张力、Zeta电位较高,粒径较小;在不同配液浓度下,采用聚乙二醇改性油酸制备的液压液比采用醇胺改性相同油酸制备的液压液粒径更小,平均粒径小于100 nm,液压液的可过滤性更强、稳定性更高。

土壤调理剂及其粒径对酸性红壤的改良效应

针对酸性红壤的特性,结合不同粒径调理剂中物质释放规律的不同,探寻出最优的调理剂粒径。通过模拟水浸提、恒温土培、盆栽试验和野外田间试验的方式,说明随着时间的推移,所有粒径的调理剂在水中的pH值逐渐升高,且粒径越小pH值越大,直至77d时,不同粒径调理剂在水中的pH值无显著性差异;不同粒径调理剂盐基离子(K^(+)、Na^(+)、Ca^(2+)、Mg^(2+))释放量也逐渐降低,刚开始到第21d释放量线性下降,之后慢慢下降最后趋于平稳。在第7d到21d之间,不同粒径调理剂中钾、钠和镁离子的释放量出现了相等的时间点,而钙离子释放量相等的时间段出现在第21d到35d间。土培试验表明所有粒径的调理剂对酸性红壤的pH值,钾钠钙镁离子含量和速效养分含量有不同程度的提升,其中粒径1~2 mm和2~3 mm的调理剂对土壤盐基离子(K^(+)、Ca^(2+)和Mg^(2+))含量提高显著高于其他粒径,分别提高了34.48%和31.03%、61.94%和47.01%与83.33%和70.08%,盆栽花生施用调理剂后,土壤中得pH值增加了0.09~0.18个单位,土壤交换性H+和交换性Al3+含量分别降低了0.01~0.08cmol(+)/kg和0.28~1.48 cmol(+)/kg,田间试验中花生产量较优处理是调理剂粒径1~2 mm和2~3 mm,显著高于其他处理,产量分别提高了25.18%和29.51%,土壤调理剂粒径范围1~2 mm和2~3 mm对酸性红壤的改良效果显著高于其他粒径。

铜烟灰回收制备纳米氧化锌及其吸波特性研究

铜烟灰资源回收对铜冶炼的经济性与环保性有着重要的意义。本文针对铜烟灰设计了一种湿法回收锌并制备纳米氧化锌的流程,初步实现了从铜烟灰回收到吸波材料制备的工艺。首先使用硫酸浸出工艺对烟灰进行处理;再进入除铁与除铜净化流程,制备出高浓度ZnSO4,其中锌平均浸出率达到98.74%;然后以ZnSO4为原料使用直接沉淀法完成前驱体制备;最后通过焙烧细化粒径,使成品粒径低于56 nm。制备过程中,通过升温速率控制颗粒状纳米氧化锌的粒径,得到平均粒径为24~56 nm的样品。在此基础上,对不同粒径纳米氧化锌进行了X波段(8.2~12.4 GHz)与Ku波段(12.4~18 GHz)的吸波性能测试。测试结果表明,平均粒径为56 nm的纳米氧化锌,在8.2~18 GHz频率范围内,吸波反射率低于-10 dB的带宽达到1.47 GHz,初步达到军事工业应用的标准。

凝胶电解液及其对电池性能影响的研究

从凝胶剂含量、硫酸溶液密度和温度三个方面,研究了对三种不同粒径的凝胶电解液性能的影响,同时探讨了三种不同粒径凝胶剂对电池性能的影响。结果表明,凝胶剂的粒径与含量、硫酸溶液密度、温度都是影响凝胶电解液性质的关键因素。电解液中凝胶剂含量对蓄电池容量和低温性能有一定的影响。凝胶剂粒径越小,比表面积越大,活性也越强,但是颗粒越细,稠度就越大,触变性也越高,同时介质也越难以分散。

切片酸溶综合法测试硬化混凝土内部骨料方法

采用切片法及酸溶法测试硬化混凝土内部骨料含量及最大骨料粒径,结合两种方法对混凝土内部骨料情况进行分析。以某工程为例,详细介绍切片法及酸溶法的基本原理和实验步骤,结合工程实际对两种方法的侧重点和优劣进行分析。