UHPM改性火龙果皮膳食纤维工艺优化及其结构表征研究

研究火龙果皮膳食纤维超高压微射流(UHPM)改性工艺优化,并对改性后的膳食纤维结构进行分析。以火龙果皮为原料,采用UHPM进行处理,研究UHPM压力、液料比和处理次数对可溶性膳食纤维(SDF)含量的影响,通过响应面试验优化UHPM改性工艺条件,并对UHPM改性前后的火龙果皮膳食纤维显微结构、扫描电镜照片、红外光谱特性进行分析。结果表明:优化的火龙果皮膳食纤维UHPM改性工艺为压力165 MPa、液料比20∶1 g/mL、处理4次。该条件下火龙果皮膳食纤维的SDF含量为29.12%。同未经UHPM处理的样品相比,165 MPa处理的火龙果皮膳食纤维,细胞被充分破碎,膳食纤维的氢键破坏。表明UHPM是改性火龙果皮膳食纤维适宜的方法。

Effect of Ultra High Pressure Processing on the Particle Characteristics of Lotus-seed Starch

In this paper, the time dependent effects of various pressure treatments on the characteristics of lotus-seed starch which was modified by ultra-high pressure （UHP） were investigated. The results showed that the polarization cross of lotus-seed starch granules was weakening gradually with increasing the treatment time, which indicated the termination of their ordered crystallite structures. The morphologies of granules were collapsed once the UHP was kept at 500 MPa for 60 minutes. The particle size analysis demonstrated that the granule size and distribution of lotus-seed starches increased as the treatment time was prolonged. X-ray diffraction studies showed that the intensity of the feature diffraction peaks of starch decreased and eventually disappeared with increasing the treatment time, and B-type transformation pattern was observed. The Fourier transform infrared spectra （FTIR） analysis of starch showed that the UHP is a physical modification processing because no new groups formed. The research showed that UHP processing at certain degree is capable to achieve the modification of lotus-seed starch. It is of significance for the deep processing of lotus-seed products.

粗骨料对超高性能应变硬化水泥基复合材料(UHP-SHCC)性能的影响

根据超高性能混凝土(UHPC)的制备理论和应变硬化水泥基复合材料(SHCC)的设计原理,制备了超高性能应变硬化水泥基复合材料(UHP-SHCC),研究了钢纤维改性处理和粗骨料的级配(最大粒径分别为6.00、8.00、9.75 mm)与掺量(0、5%、11%、15%)对UHP-SHCC抗压强度和拉伸行为的影响。结果表明:与未改性钢纤维相比,改性钢纤维使UHP-SHCC的应变硬化行为更明显;通过合理调控粗骨料的级配和掺量,有效提高了UHP-SHCC的抗压强度,改善了UHP-SHCC的拉伸应变硬化效果,但随着龄期从7 d增至28 d,UHP-SHCC的应变硬化效果略有减弱。

Fabric and Deformation of Omphacite in Dabie Ultra-high-pressure Ecologites

The rheological characters of omphacites in Dabie ultra-high-pressure eclogite have been studied in terms of fabric, dislocation and micro-structures. 1. The eclogite has undergone high-temperature deformation, thus forming omphacite lattice preferred orientation. In addition to creep dislocation, the omphacite ductile deformation may have other mechanisms, such as diffusion creep and grain boundary migration. 2. The main-phase deformation of eclogite is coaxial, but asymmetry strain also exists due to strain partitioning in the Dabie orogenic belt. 3. The twin measured by the universal stage is (100), indicating that omphacite high-T deformation was superimposed by low-T deformation. 4. Subgrain structure is common in omphacite, but the deformation features of the omphacites in the Shuanghe area and Bixiling area are different, the latter being dominated by dynamic recrystallization. 5. The Flinn plots show that the strain of omphacite belongs to the constriction ellipsoid and stretching strain, which is similar to the result of the omphacite fabric analysis.

Structural, Pasting, and Thermal Properties of Ultra-high Pressure-treated Lotus Seed Starch

Lotus seed starch （15%, w/w） was subjected to ultra-high pressure （UHP） at 500 MPa for 10～60 min. The effects of UHP on the structural, pasting, and thermal properties of starch were investigated using solid-state 13C CP/MAS NMR, differential scanning calorimetry （DSC）, HPSEC-MALLS-RI, and a rapid visco analyzer. The 13C CP/MAS NMR results revealed a reduction in the relative crystallinity and peak intensity of the crystalline state with increasing the UHP time. The molecular weight of native starch was 1.433 × 107 Da, which was higher than that of the UHP-treated starch. Viscograms of UHP-treated starch revealed an increase in paste viscosity, peak time, and pasting temperature and a reduction in breakdown and setback viscosity compared to the native starch. Furthermore, the DSC results showed a reduction in gelatinization temperature and gelatinization enthalpy with increasing the UHP time.

Effect of Ultra-high Pressure Treatment on the Quality of Persimmon Pulp

Different pressures and different durations of ultra-high pressure treatment were conducted for persimmon pulp after vacuum packing.The results showed that with the increase of pressure and extension of duration,the total number of bacteria in persimmon pulp decreased gradually.The treatment at 400 MPa for 15 min could meet the requirement of commercial sterility.After treatment,the color and the contents of soluble sugar,soluble solids and titratable acid of persimmon pulp were not changed significantly compared with the control group(P >0.05).The content of vitamin C in persimmon pulp declined gradually with the increase in pressure and time,with the maximum loss of 8.06% observed at 600 MPa for 20 min.Peroxidase( POD) activity also declined gradually with the increase of pressure and time.The activity of polyphenol oxidase( PPO) declined gradually with the increase of time,and increased first and then decreased with the increase of pressure.The content of polyphenols increased first and then decreased with the increase in pressure,and tended to increase overall with the increase in time.Under the treatment of 400 MPa for 20 min,the content of polyphenols reached the maximum.The antioxidant capacity of persimmon pulp after ultra-high pressure treatment was higher than that in the control group,but no significant differences were found among the treatment groups( P > 0.05).Compared with the control group,soluble tannin content was increased after ultra-high pressure treatment,but was far below the critical value for astringency(2 mg/g).In conclusion,ultra-high pressure treatment has only a slight effect on the sensory quality of persimmon pulp and can maintain its nutritional quality to a large extent and improve its antioxidant capacity.Moreover,ultra-high pressure treatment can eliminate astringency completely.

Effects of ultra-high hydrostatic pressure on foaming and physical-chemistry properties of egg white

The influences of ultra-high hydrostatic pressure treatment on foaming and physical properties (solubility, hydrophobicity and sulfhydryl content) of egg white were investigated. A pressure range of 0-500 MPa, time range of 0-20 min and pH range of 7.5-8.5 were selected. The foaming property of egg white is improved by 350Mpa and 10min. The treatment resulted in in- crease of sulfhydryl content of egg white, while solubility and hydrophobicity were significantly decreased.

Microstructures of TiAl_3 intermetallic compound solidified under ultra high pressure

The phase constitutes and microstructures of TiAl3 intermetallic compound solidified under vacuum and 5.5GPa pressure conditions were investigated. The results show that the phase constitutes of Ti80Al alloy solifified under vacuum and ultra high pressure are the same as those of TiAl3+Al. There are no new phases generated. However, under ultra high pressure solidification, the morphology of TiAl3 changes obviously. The shape of TiAl3 changes from pin-like to massive. Furthermore, Ti content in Al increases under ultra high pressure solidification. Analysis results indicate that the change of microstructure under ultra high pressure is involved in the influence of solute diffusion coefficient, the microstructure and stability of the solid/liquid interface with pressure mainly.

Compression fracture behavior and mechanical properties of ultra high pressure solidified titanium-aluminium intermetallics

The compression fracture behavior and mechanical properties of Ti80Al alloy and Ti48Al alloy solidified under 5.5GPa pressure condition were studied. The results show that the fracture of Ti80Al alloy solidified under high pressure has the characters of cleavage fracture and intergranular crack differing with cleavage fracture of that under vacuum. The fracture of Ti48Al alloy solidified under high pressure is cleavage fracture like that under vacuum. The compression strength of vacuum condition solidified Ti80Al alloy is 316MPa. However when the solidification pressure is increased to 5.5GPa, the compression strength of Ti80Al is increased to 440MPa. In the mean time, during ultra high pressure solidification the hardness of Ti80Al alloy and Ti48Al alloy increase from 8.755GPa and 5.408GPa under vacuum to 9.572GPa and 6.227GPa respectively, and elastic modulus also increase from 279.3GPa and 232.3GPa under vacuum to 295.8GPa to 252.9GPa respectively.

Enzymatic Hydrolysis of Hairtail Surimi in an Ultra-High Pressure Bioreactor

Amino acids have been extracted from Hairtail surimi using enzymes in an ultra-high pressure bioreactor. The extraction efficiency of different enzymes including papain, trypsin, and proteases (acid, neutral, alkaline) also has been evaluated, and it has been discovered that neutral protease behaved the best. The amino acids were analyzed using automatic amino acid analyzer, and the enzymatic digestion conditions were optimized. For neutral protease, the optimal condition was 50℃, 250 MPa, pH 7.0. Material to liquid ratio of enzyme is 6%. More than 29 amino acids were detected after 24 hours of hydrolysis;the enzymatic hydrolysis rate can reach 83.29%. The results show that enzymatic digestion under ultra-high-pressure provides a very promising approach to extract amino acids from Hairtail surimi.

The Dabieshan Coesite-bearing Eclogite Terrain-A Late Archaean Ultra - high- Pressure Metamorphic Belt

A U -Pb zircon age of 2774±24 Ma for eclogite from the Bixiling rock body of Anhui Province, central China, indicates that the Dabieshan coesite-bearing eclogite was probably formed in the Late Archaean. A phengite Ar-Ar isochron age of 662±13 Ma for the eclogite confines also an upper limit age of its subsequent retrograde metamorphism in the Precambrian. The results of isotopic dating for such type of eclogite coincide with the geological features of its restricted occurrence within the Archaean metamaorphic terrain composed of the Dabie Group. It is believed that the Dabieshan coesite-bearing eclogite terrain might be a Late Archaean ultra-high-pressure metamorphic belt. The Dabie Mountains area was the eastward extension of the southern Qinling structural belt during the Triassic. Both the Dabie Group and the coesite-bearing eclogite hosted therein underwent a late-stage dynamic metamorphic event. The present authors have obtained a muscovite Ar-Ar isochron age of 192.6±2.8 Ma from plagioclase gneiss and a hornblende Ar-Ar plateau age of 230.7±4.6 Ma for the low amphibolite in eclogite respectively, which represent the Indosinian reworking ages of the original metamorphic rocks of the Dabie Group gneiss and coesite-bearing eclogite.

Study on the Generation of Ultra-Wideband (UWB) High Power Microwave

The experimental study of ultra-wideband (UWB) technology, its generation and on-line measurement are presented. An experimental repetitive UWB system is designed, manufactured, and tested. High-pressure spark gap switch and its components, as well as oil spark gap switch are studied experimentally on the system. Experimental results indicate that the system operates at a 200 pps repetitive rate with a stable performance. 100 MW peak power UWB pulses are obtained on the system. Fast-time response capacitive divider is designed and fabricated, allowing for an accurate measurement of the high power UWB signal. The main issues related to the design of the switch and the UWB signal online measurement are discussed.

Experimental study on liquid immiscibility of lamprophyre-sulfide melt at high temperature and high pressure and its geological significance

With lamprophyre and pyrite from the Laowangzhai gold deposit, Yunnan Province, China, as starting materials, and at pressures from 1.5 to 3.0 GPa and temperatures from 1160 to 1560℃ , an experimental study was carried out on the liquid immiscibility of lamprophyre-sulfide melt at high temperature and ultra-high pressure in the DS-29A cubic 3600T/6-type high pressure apparatus. Results showed that the liquid immiscibility of lampro-pyre-sulfide melt in the magmatic system would happen during the early magmatic evolution (high temperature and high pressure conditions) and was controlled by temperature and pressure. The sulfide melt which was separated from the lamprophyric melt would make directional movement in the temperature and pressure field and assemble in the low-temperature and low-pressure region. Because the density of SM is higher than that of the lamprophyric melt, the former would gather together at the bottom of the magma chamber and there would exist a striking boundary between the two melts. On the other hand, the results also suggested that there would be little possibility for lampro-phyric magma to carry massive gold, and lamprophyres can't provide many of oreforming materials (Au) in the processes of gold mineralization.

中国石化超深层钻完井关键技术挑战及展望

超深层是中国石化油气勘探开发的重要增储上产领域。针对超深层勘探开发需求和高温高压及复杂地质环境带来的工程挑战,中国石化持续开展关键技术攻关,在钻完井基础理论和方法、钻完井装备、高温井筒工作液、耐高温井下工具仪器和完井测试等方面取得关键技术进展,保障了120口超8 000 m油气井的安全钻探,钻深能力突破9 000 m,助推塔里木盆地顺北大型超深油气田建设、四川盆地海相特深层油气勘探开发突破,为保障超深层油气勘探开发提供了有力的工程技术支撑。随着油气勘探开发不断向更深层推进,技术升级转型需求日益迫切,需进一步夯实理论研究基础,突破耐高温关键工具仪器和井筒工作液,加快推进钻完井工程技术向数智化转型,为保障深层、超深层油气高效勘探开发和加快技术升级转型提供工程技术支撑。

塔里木油田超深层钻井技术进展及难题探讨

当前,塔里木油田以超深特深层为代表的深地油气资源开发对满足我国经济发展需求和保障能源安全至关重要。经过数十年的探索和实践,塔里木油田创新形成了超深复杂井井身结构设计、超深难钻地层钻井提速、超深大斜度井水平井钻井、超深复杂地层钻完井液、超深复杂地层固井、高温高压井完整性、超深复杂井井控等一系列超深层钻井技术,保障深地油气勘探获得重大突破并创造多项纪录。伴随超深井数量持续增加,工程地质条件更加复杂,井下环境更加苛刻,超深层钻井过程势必面临新的工程难题和挑战,严重制约深地油气资源安全高效开发。为此,通过概括塔里木油田钻井工程技术发展历程,系统梳理了深地钻井工程技术取得的主要技术进展,并结合新的勘探开发形势与油气开发要求,指出了塔里木油田钻井工程技术从超深层迈入特深层新时期的焦点问题及攻关发展方向,为国内外深地复杂油气井安全高效钻进提供借鉴和参考。

UHPC的研究进展及其在混凝土结构中的应用

超高性能混凝土(Ultra-High Performance Concrete,简称UHPC),也称作活性粉末混凝土(RPC,Reactive Powder Concrete),是近三十年来最具有创新性的水泥基工程材料。由于其优越的性能,自问世以来,其就受到了土木工程界的广泛关注与应用。为此,从它的材料研发、力学性能、在钢筋混凝土结构中的应用、与预应力结合的应用研究以及在未来工程中的应用与展望等方面进行了论述。

特高压平板闸阀设计与密封性能分析

针对特高压井口平板闸阀设计指导空缺问题,参考API 6A和API 6D标准中的平板闸阀设计参数确定方法,给出175 MPa工作内压下阀体通径为78 mm的平板闸阀设计参数,补充并完善了国内外特高压井口平板闸阀设计方法,对所设计的平板闸阀采用有限元法分析其在螺栓预紧工况、额定工作内压工况和1.5倍静水压工况下的密封性能。所设计的平板闸阀可以满足密封准则,且能应对一定量的动载荷,可为特高压井口平板闸阀设计提供参考。

超高压预处理紫苏蛋白与大豆蛋白复配蛋白肉的工艺条件优化

利用超高压(ultra-high pressure,UHP)技术预处理紫苏蛋白与大豆蛋白复配蛋白肉,并利用正交实验探究其最佳工艺条件。采用UHP预处理技术,以紫苏蛋白和大豆蛋白等质量比复配为主要原料,谷朊粉、淀粉、牛肉香精和魔芋胶等为辅料制备新型复合植物蛋白肉。采用单因素实验和正交实验考察水分添加量、魔芋胶添加量和UHP压力对蛋白肉产品的咀嚼性、硬度、弹性、黏弹性、蒸煮和解冻特性的影响。复配蛋白肉的最佳工艺条件(以干基计)为水分添加量40%、魔芋胶添加量0.3%、UHP压力500 MPa。在此工艺条件下所得的紫苏蛋白复合肉与纯大豆蛋白肉相比质构性能最佳,其咀嚼性高达46.993 J,比纯大豆蛋白肉高近10倍,并且蒸煮和解冻损失率较低。该研究可为UHP的利用和紫苏蛋白肉的工艺开发提供初步的科学思路,为植物蛋白肉的机制与工艺研究提供一定理论和技术支持。

超高压处理对鲜榨复配果汁品质及货架期的影响

为使经杀菌处理后果汁的活性成分和风味物质更接近原鲜榨果汁,本研究以猕猴桃、菠萝、芒果为原料制备复配果汁,对比超高压处理与热处理(85℃、5 min)两种杀菌方式对鲜榨复配果汁品质及货架期的影响。结果表明:复配果汁比例V菠萝原浆:V猕猴桃原浆:V芒果原浆=4:2:4时,与传统热处理相比,在450 MPa、25℃、15 min超高压条件下处理,pH、b^(*)值、可溶性固形物无明显差异(P>0.05),维生素C含量损失减少12.1%、多酚含量损失减少17.5%,品质更接近于未处理果汁;通过对复配果汁主要挥发性成分进行分析,烯类、酯类、醇类、酮类、醛类等风味物质的损失显著小于(P<0.05)热处理,且蒸煮味物质糠醛没有生成,丙酮和1-辛烯-3-酮相对含量分别减少68.4%、41.4%;菌落总数、霉菌和酵母菌杀菌效果均符合饮料现行有效卫生标准;通过Q_(10)模型对货架期进行预测,在4℃条件下储藏,其货架期可达到103 d。综上,超高压处理鲜榨复配果汁在有效杀灭微生物的同时更利于复配果汁保持天然品质及其货架期。

超高压在植物活性物质提取中的应用研究进展

植物中含有多种活性物质,并具有抗氧化、抗菌、免疫调节、抗炎等多重功效,如何从植物中快速、高效、环保地提取活性物质一直以来是食品、医药、化妆品等行业最重要的研究领域之一。超高压技术作为一种非热加工技术,近年来被广泛研究用于食品加工、提取等方面。超高压提取技术的应用提高了植物活性物质的提取率,缩短了提取时间,可作为一种替代传统固液萃取植物活性化合物的方法。该文重点综述了超高压技术的发展历程及其在植物提取方面的发展应用,超高压提取原理与提取工艺,及其在黄酮、多酚、多糖等多种活性物质提取中的应用,与传统热回流提取方法相比,超高压提取技术可以在常温或较低温度下进行,可有效缩短提取时间,提高生物活性,降低能耗。但超高压在提取植物活性物质方面的应用还面临超高压提取理论基础不完善,提取物生物活性研究有待深入、设备成本高等诸多挑战,有必要探索超高压与其他提取方法相结合的协同提取作用,进一步揭示该技术所涉及的工作机制,以期为深入应用超高压技术提取植物活性物质提供理论参考。