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1.
LI Zhenxing LIN Hong CAO Limin 《中国海洋大学学报(英文版)》2006,5(2):115-118
The present study was undertaken to determine whether high intensity ultrasound could reduce the allergic properties of shrimp allergens. Reducing the allergenic properties of these allergens will be beneficial to allergic individuals. Samples of shrimp protein extract and shrimp muscle were treated by high-intensity ultrasound with water bathing at 0 ℃ or 50 ℃ for different time periods. The treated and untreated samples were then analyzed by SDS-PAGE, Western blots and competitive inhibition ELISA （Ci-ELISA） to determine the shrimp allergenicity. The results show that high-intensity ultrasound has no effect on allergenicity when the extracts were treated at 0℃. However, a significant decrease was observed in the level of the major shrimp allergen, Pen a 1, when the samples were treated at 50 ℃. In the determination of allergenicity with CiELISA, a reduction in IgE binding was also observed. 相似文献
2.
A new sample treatment was developed for the determination of dissolved cadmium in Tagus estuarine waters, based on focused ultrasound in conjunction with small volumes in the extraction steps for Cd pre-concentration. Cadmium was first pre-concentrated using a classical approach (APDC as the complexing agent and MIBK as the organic phase) and then back-extracted into HNO3 with the aid of focused ultrasound, which reduced the acid concentration by more than one order of magnitude (from 4 to 0.1 mol L− 3). This sample treatment was accomplished in less than 5 min, using low sample volume (20 mL), and low-volume, low-concentration reagents. The pre-concentration factor used in this work was 25, but different sample/organic volume ratios may be used in order to increase that value. The limit of detection and the limit of quantification in Tagus water samples were 0.03 nmol L− 1 and 0.1 nmol L− 3, respectively. Recoveries from spiked Tagus water were higher than 90%. The procedure was validated using the reference estuarine water NRC-SLEW-3. In the solubilization of Cd particulate, bath ultrasonication was used in conjunction with HNO3 + HCl, followed by H2O2, which took about 2 instead of the usual 12 h (cooling included) when high-pressure microwave digestion is used. 相似文献
3.
Rui CHEN Xiaoli WANG Yonggang ZHANG Xueqi FU 《中国地球化学学报》2006,25(B08):128-129
The use of membranes is a widely employed, versatile, and effective separation process. One of the limiting aspects in applying microfiltration （MF） for wastewater treatment is that of problems with membrane fouling and consequent flux reduction. Membrane fouling occurs by the irreversible deposition of retained particles, colloids, macromolecules, salts, etc. at the membrane surface and/or inside the membrane. The predominant fouling mechanisms observed with MF membranes are classified as three categories： the build-up of a cake layer on the membrane surface, blocking of membrane pores, and adsorption of fouling material on the membrane surface or in the pore walls. Although many techniques have been developed to overcome fouling, studies on membrane cleaning still seem to be insufficient for practical membrane filtration systems. Current membrane cleaning technologies include hydraulic, chemical, and mechanical methods. Ultrasound （US） has been widely used as a method of cleaning materials because of the cavitation phenomenon. In this study, US cleaning technique was applied to removing the fouling of polyvinglidenefluoride （PVDF） MF membrane, which was used to treat yeast cell and isolated soybean protein （ISP） solution, respectively. The US employed 40 kHz frequency and the output power of 1.43-2.85 W/cm^2. The evolution of the cleaning effect is followed by the measurements of the flux recovery rate （FRstat） and the cleaning time cycle. Results showed that the membrane property, which was fouled by yeast cell solution, could be recovered by water cleaning with US irradiation. And the cleaning time with the same FRstat decreased with the increase of US intensity. 相似文献
4.
将先进的多普勒超声成像技术运用于栉孔扇贝(Chlamys farreri)和虾夷扇贝(Patinopecten yessoensis)循环生理学的研究中,首次量化了扇贝心率(HR)、血流加速度(ABF)、收缩峰值速度(PS)、舒张末期速度(ED)、血液最大瞬时血流量(Max-IBF)、血液最小瞬时流量(Min-IBF)、收缩期与舒张期流速比(S/D)和阻力指数(RI)等指标,对比了两种不同耐温性扇贝的循环生理指标差异。结果表明,两种扇贝HR、ABF、PS、ED、Max-IBF、Min-IBF与水温均呈正相关;在10—25°C间,栉孔扇贝和虾夷扇贝HR范围分别为16—39、14—31次/min,ABF范围分别为1.75—15.84、0.99—7.41cm/s2,PS范围分别为3.54—8.09、2.32—8.85cm/s,ED范围分别为1.51—3.15、1.09—4.23cm/s,Max—IBF范围分别为0.051—0.193、0.137—0.316m L/s、Min—IBF范围分别为0.025—0.072、0.022—0.131m L/s、RI范围分别为0.49—0.69、0.42—0.54,S/D范围为2.28—2.83、1.75—2.12。同一温度下栉孔扇贝的HR、ABF、PS、ED指标水平均高于虾夷扇贝,Max-IBF、Min-IBF水平均低于虾夷扇贝;两种扇贝RI和S/D指标均在一定范围内波动。研究显示,虾夷扇贝在较低的心脏和血流搏动节律下保持了高效的血液流通,从而以相对较少的能量消耗维持了其机体代谢对血液循环的需求,这也与其冷水性的生态习性相适应。 相似文献
5.
Drilling fluid is a common flushingmedium used in pile foundation, geological drilling and petroleum drilling. Study on ultrasonic propagation properties in drilling fluid is of vital importance, not only for developing equipments to non-contact measuring concrete casting level for bored pile, but also for developing equipments considering drilling fluid as signal channel. The existence of clay particlesmakes the ultrasonic propagation and attenuation in drilling fluid much different from pure water. In order to know the relation among ultrasound frequency, slurry density and depth, a series of laboratory experiments about ultrasound propagation in water-based bentonite slurry were finished. Wavelet method was adopted to process the gained original waves of ultrasonic propagation in slurry, so we knew the velocity and attenuation coefficient of ultrasound propagated in different drilling fluids with different density. The first group experiments shows that with density of drilling fluid increase, ultrasonic velocity will decrease but attenuation coefficient will increase if ultrasonic frequency keep constant. The second group experiments shows that the power of ultrasound will intensify in small bore hole, the attenuation coefficient ismuch smaller than theoretical value. 相似文献
6.
针对超声心动图像噪声大,边界模糊,灰度分布不均匀等特点,提出了一种新的图像分割算法.首先对超声图像进行滤波和边缘锐化等预处理,然后再使用GVFSnake模型对预处理后的图像进行分割,从而提取出心室的边界.经试验证明,这种新的超声心动图像分割算法,比传统的超声图像分割算法在图像分割精度上有显著的提高. 相似文献
7.
Ultrasound-assisted solvent extraction was confirmed as a novel,effective method for separating lipid from mackerel pro-tein,resulting in a degreasing rate (DR) of 95% and a nitrogen recovery (NR) of 88.6%.To obtain protein hydrolysates with high ni-trogen recovery and low bitter taste,enzymatic hydrolysis was performed using eight commercially available proteases.It turned out that the optimum enzyme was the ‘Mixed enzymes for animal proteolysis’.An enzyme dosage of 4%,a temperature of 50℃,and a hydrolysis time of 300 min were found to be the optimum conditions to obtain high NR (84.28%) and degree of hydrolysis (DH,16.18%) by orthogonal experiments.Glutamic acid was the most abundant amino acid of MDP (defatted mackerel protein) and MDPH (defatted mackerel protein hydrolysates).Compared with the FAO/WHO reference protein,the essential amino acid chemical scores (CS) were greater than 1.0 (1.0 1.7) in MDPH,which is reflective of high nutritional value.This,coupled with the light color and slight fishy odor,indicates that MDPH would potentially have a wide range of applications such as nutritional additives,functional ingredients,and so on. 相似文献
8.
J.N. Walsh P.A. Taylor A. Buckley T.W. Darling J. Schreuer M.A. Carpenter 《Physics of the Earth and Planetary Interiors》2008,167(1-2):110-117
Values of bulk modulus (K), shear modulus (G) and mechanical quality factor (Q) have been determined for polycrystalline samples across the CaTiO3 (CST0)–SrTiO3 (CST100) solid solution by resonant ultrasound spectroscopy. Because of similarities with low frequency elastic and anelastic anomalies due to twin wall motion reported in previous studies, a working hypothesis is developed in which dissipation processes are interpreted in terms of twin wall displacements. At high temperatures in CST50 the stability field of the I4/mcm structure is marked by the disappearance of all resonance peaks (superattenuation). This is attributed to anelastic domain wall sliding. At room temperature the I4/mcm phase of CST70 and CST80 has values of G which are lower than those of cubic or orthorhombic phases, and a concomitant drop in Q is interpreted as implying that the domain wall pinning process reported elsewhere to occur below 400–450 K is only partial. A similar drop in G and Q was found in CST95 below the transition at 238 K. The I4/mcm ↔ Pbcm transition in CST70 at 230 K is marked by an abrupt increase in Q, suggesting that mobile twins in crystals with the I4/mcm structure become effectively immobile in antiferroelectric crystals with the Pbcm structure. The I4/mcm ↔ Pnma transition in CST50 is marked by a similarly abrupt increase in Q, consistent with twin walls becoming effectively immobile also in crystals with the Pnma structure. A fall in Q below 800 K in CST0, however, could imply that a degree of twin wall mobility might develop in Pnma crystals if the tetragonal spontaneous strain departs significantly from zero. The remarkable attenuation behaviour of crystals with the I4/mcm structure at the relatively low stress conditions which apply during resonances of a parallelepiped with edge dimensions of 2–4 mm, is consistent with the view that a characteristic signature for tetragonal CaSiO3 in the Earth's lower mantle should be a marked attenuation of seismic waves. 相似文献
9.
The right-rectangular parallelepiped resonance (RPR) form of resonant ultrasound spectroscopy (RUS) is applied to monoclinic crystal symmetry to determine the 13 adiabatic elastic constants, Cij, of single-crystal chrome-diopside Di0.93Hd0.03Ur0.02X0.02 (Di, diopside; Hd, hedenbergite; Ur, ureyite; X, other or unknown). These data represent the first published values of the elastic tensor for a monoclinic single-crystal determined by the RPR method, thus demonstrating the feasibility of this method for studying elasticity of low-symmetry crystals. The lowest 62 modal frequencies of a gem-quality specimen were measured and identified at ambient temperature and pressure. Inverting the modal frequencies results in, respectively C11, C22, C33, C44, C55, C66, C12, C13, C23, C15, C25, C35, C46 values (GPa) of 228.1(1.0), 181.1(0.6), 245.4(1.3), 78.9(0.3), 68.2(0.2), 78.1(0.2), 78.8(0.5), 70.2(0.7), 61.1(0.7), 7.9(0.5), 5.9(0.5), 39.7(0.4), and 6.4(0.2), where numbers in parentheses indicate experimental uncertainty. The corresponding isotropic bulk, KS, and shear, G, moduli are 116.5 (0.9) and 72.8(0.4) GPa, respectively. When comparing these results with other pyroxene data, we find systematic correlations between M2 site composition and Cij values for most, but not all, moduli. Unusual compositional dependence near end-member diopside is seen for a few moduli, and is propagated to the KS and G moduli, which should prompt a reexamination of some Cij values of end-member diopside. 相似文献
10.
Values of the complete adiabatic elastic tensor for single-crystal chrome-diopside (a monoclinic pyroxene mineral) are presented from 298 to 1,300 K. The data were obtained using resonant ultrasound spectroscopy (RUS). They are the first published results for the temperature T dependences of the 13 individual elastic constants C
ij
of any clinopyroxene mineral. Each C
ij
is appropriately described by a linear function in T throughout the range of T. Values for each (∂C
ij
/∂T)
P
in GPa K−1 are as follows: C
11, −0.0291; C
22, −0.0248; C
33, −0.0179; C
44, −0.0103; C
55, −0.0077; C
66, −0.0152; C
12, −0.0119; C
13, −0.0064; C
23, 0.0000; C
15, 0.0025; C
25, 0.0022; C
35, −0.0046; and C
46, 0.0026. Values of (∂M/∂T)
P
in GPa K−1, where M represents an isotropic bulk property calculated from the C
ij
data, are as follows: adiabatic bulk modulus K
S
, −0.0123; isothermal bulk modulus K
T
, −0.0178; and shear modulus G, −0.00998. Some diopside derivatives, notably (∂K
S
/∂T)
P
, (∂K
T
/∂T)
P
, and (∂V
P
/∂T)
P
, where V
P
is the compressional wave velocity, have smaller magnitudes than all other minerals of importance in Earth’s mantle, thus, confirming predictions from systematics studies. We find several dimensionless quantities for this monoclinic mineral have normal values compared to other mantle minerals. Further, αK
T
(α is the volume coefficient of thermal expansion) for diopside is approximately independent of both T and volume V at elevated temperature, so its equation of state is accurately expressed in simplified form. 相似文献