Fatty acids,sterols, and tocopherols composition in seed oil extracts from four moroccan ecotypes of Ceratonia siliqua L.

Morphological characterization was investigated by agro-morphological criteria related to carob seed size in four different moroccan regions collected in 2018 and 2019. There was no significant difference (p ≤ 0.05) on the seeds lengths and widths. However, a significant difference between seeds thickness and total seeds weight per pod (p ≤ 0.05) were observed between these four populations. The fatty acid, sterol, tocopherol, hydrocarbon, and the unoxygenated composition of carob seed extracts (Ceratonia siliqua L.) were studied. The mean fat yield of the seeds obtained is 1.53%–2.17%, 2.14%–2.15%, 1.61%–1.62%, 1.71%–1.75% for, respectively, the P1 (Meknes), P2 (Fez), P3 (Khemisset), and P4 (Marrakech) in 2018 and 2019. The seed oil was extracted with hexane and the analysis of the fatty fraction was performed by gas chromatography–mass spectrometry (GC–MS). Results show that the major fatty acids for 2018 and 2019 are linoleic acid (61.48%–61.52%, 52.12%–52.14%, 57.76%–58.15%, 61.33%–61.52%), palmitic acid (15.78%–15.81%, 16.44%–16.45%, 19.11%–18.37%, 20.24%–20.32%), oleic acid (11.03%–11.04%, 8.72%–8.82%, 8.51%–8.61%, 8.41%–8.53%), stearic acid (4.35%–3.14%, 5.40%–5.43%, 3.12%–3.13%, 0.96%–1.56%), and cerotic acid (0.62%–0.53%, 4.51%–4.52%, 4.03%–4.06%, 3.84%–3.87%). The unsaturated fatty acids (69.39% in 2018 and 69.68% in 2019) are the most dominant in the four seed extracts compared to the saturated fatty acids. In addition, the oil carob seeds analysis revealed the presence of γ-tocopherol, α-tocopherol and four sterols that included campesterol, stigmasterol, and β-sitosterol. Moreover, the determination of hydrocarbon and un-oxygenated compounds confirmed the existence of major compounds such as heptadecane, 2-methyltriacontane, 1-iodo hexadecane and 1-iodo octadecane. The hierarchical analysis based on the morphological and chromatographic characterization of the seeds allowed the identification of three groups. Consequently, the first group consisted of populations from Marrakesh (P4) and Khemisset (P3), the second group consisted of the P1 from Meknes, and the P2 from Fez constituted the third group.     

氨基酸透明洁面啫喱体系研究

以椰油酰甘氨酸钠和月桂酰谷氨酸钠2种氨基酸表面活性剂体系为研究对象,通过复配其他温和表面活性剂,选用2种增稠剂异硬脂酰胺MIPA/月桂酸甘油酯(SPA-80)和鲸蜡硬脂醇聚醚-60肉豆蔻基甘醇(GT 282S)对体系进行增稠,考察2种增稠剂在不同氨基酸表面活性剂体系中的增稠性能。在此基础上,通过调节体系pH以获得最佳黏度、泡沫量、透明度和稳定性。研究结果表明,椰油酰甘氨酸钠体系中,SPA-80和GT 282S各添加1.5%,调节pH 6.8时黏度最高,且具有最优的泡沫量、低温透明度和稳定性;月桂酰谷氨酸钠体系中,SPA-80和GT 282S添加量分别为2.7%和1.6%,调节pH 5.8时黏度最高,且具有最优的泡沫量、低温透明度和稳定性。     

C/C–SiC composites derived from single-source poly(silylene–acetylene) precursors

Carbon-fiber-reinforced carbon–silicon carbide (C/C–SiC) composites were prepared by impregnating carbon fibers with ethynylphenyl-terminated poly(silylene–acetylene) (EPTSA) as a single-source precursor with subsequent hot pressing and pyrolysis. The structural evolution, crystallization behavior, and graphitization of bulk C–SiC ceramics, as well as their mechanical properties and ablation behavior, were investigated. The EPTSA precursor starts to transform into inorganic SiC ceramic materials at 800°C, which is characterized by an amorphous structure with weight loss, shrinkage, and densification between 800 and 1000°C. The formation of SiC crystals inhibited the growth of the graphitic structure between 1000 and 1200°C. As the temperature was raised, both graphite and SiC crystals continued to grow, and the crystalline forms became more complete. The carbon-fiber cloth (T300CF)-reinforced C–SiC composite (T300CF/C–SiC) prepared using polymer infiltration and pyrolysis (PIP) exhibited excellent mechanical properties. After five PIP cycles, the flexural strength, flexural modulus, and interlaminar shear strength of the T300CF/C–SiC composite reached 169 MPa, 32.5 GPa, and 9.38 MPa, respectively. In addition, the chopped-carbon-fiber-reinforced C–SiC composite fabricated using the PIP process demonstrated good oxyacetylene-torch ablation properties.     

Experimental and numerical investigation of the dynamic response of a ZrB2-SiC ceramic under uniaxial compression

The dynamic experimental tests were performed on cylindrical zirconium diboride-silicon carbide ceramic specimens under the uniaxial compression from 519 to 2861 s⁻¹. The effect of the strain rate on the dynamic response of a ZrB₂-SiC ceramic was investigated using experimental and numerical methods. A significant increase on the dynamic compressive strength, elastic modulus, and the dynamic tensile strength was found with the increase of the strain rate. The damage process and fracture pattern of the ZrB₂-SiC ceramic exhibited a significant strain-rate dependence under the dynamic compression. The strain rate-dependent elastic modulus and tensile strength were introduced into Johnson–Holmquist (JH-2) model to predict the dynamic compression behavior of the ZrB₂-SiC ceramic. The simulation results of the dynamic compressive strength, stress–strain relation, and fracture patterns were in good accordance with the dynamic experimental results.     

Wavelength switchable and stable single-longitudinal-mode erbium-doped fiber laser based on Mach–Zehnder interferometer and tunable filter

An erbium-doped fiber laser with all-fiber Mach–Zehnder interferometer (MZI) and tunable filter was proposed and experimentally demonstrated. In the designed fiber laser, 6?m C-band erbium-doped fiber was selected as a gain medium; the MZI comprised two waist-enlarged fiber bitapers. In the experiment, the laser threshold was 93?mW, whereas a switchable single-longitudinal-mode laser was realized within 1519.7–1564.6?nm by adjusting the tunable filter and the line interval was less than 2.5?nm; for single-wavelength laser, the peak power difference of each line was less than 4?dB, and the power fluctuation was less than 0.77?dB within 10-min scan time. A stable and switchable dual-wavelength laser was realized, the wavelength spacing of each dual-wavelength laser was less than 0.7?nm, the side-mode suppression ratio was more than 30.2?dB, and the power shift was less than 0.39?dB. The laser’s 3-dB linewidth was less than 0.1?nm.     

丙烯酸树脂分子量及其分布的测定

建立了液相凝胶渗透色谱法（ GPC）测定丙烯酸树脂分子量及其分布的方法。利用不同分子量分子在凝胶色谱中有不同的保留时间,使用了5种高分子单分散性标准品,根据其保留时间与分子尺寸关系,建立线性拟合校正曲线,快速、高效地获得高分子化合物数均分子量、重均分子量等多种平均分子量。以四氢呋喃作为流动相,使用RID检测器。数均分子量RSD=0.413％,重均分子量RSD=0.367％,线性拟合曲线,相关系数r=0.994。结果表明,该方法简便、准确,适用于丙烯酸树脂分子量及其分布的测定。     

硼钛复合交联剂的制备及其在葫芦巴胶压裂体系中的应用

以四硼酸钠、钛酸丁酯、三乙醇胺、甘油、乙二醇为原料,合成了有机硼钛交联剂,制备了葫芦巴胶压裂液。研究了主剂及配体物料比,反应温度与反应时间对交联剂成胶性能的影响。结果表明,m（四硼酸钠）：m（钛酸丁酯）=1:4,m（三乙醇胺）：m（甘油）=1:2,反应温度70℃,反应时间3h的条件下,合成的交联剂性能最优。考察了w（葫芦巴胶溶液）=0.4%,m（葫芦巴胶溶液）：m（硼钛交联剂）=100:（0.4~0.6）时,葫芦巴胶压裂液的性能,交联延时150s,耐温耐剪切性能良好;常温下,携砂比V（压裂液）：V（石英砂）=70：30时,沉降速度0.009mm•s-1;体系易破胶,破胶液黏度低于5mPa•s,对储层伤害小。     

高效疏水电荷诱导色谱介质的基团修饰及其色谱行为的初步研究

以粒径10μm、孔径300球形硅胶为载体,以γ-缩水甘油醚氧丙基三甲氧基硅烷(KH-560)为中间偶联剂,将4-巯基吡啶键合至硅胶上,制备了高效疏水电荷诱导色谱介质。通过单因素实验,探讨了反应温度、反应时间、KH-560的浓度对活化密度的影响,结果表明,在反应温度为75℃,反应时间为10 h条件下,KH-560的利用率大,可获得较宽范围的活化密度,此外还考察了缓冲液pH、反应温度、反应时间、4-巯基吡啶浓度对偶联密度的影响。结果表明,在pH=7.5的缓冲液,反应温度40℃,反应时间6 h下,4-巯基吡啶利用率高,通过控制4-巯基吡啶的浓度,可获得较宽范围的配基密度。最后,于高效液相色谱条件下,通过等度洗脱,考察了流动相pH对牛血清蛋白和溶菌酶保留因子的影响。并通过梯度洗脱,分离了不同等电点的牛血清蛋白和溶菌酶,验证了该介质的高效疏水电荷诱导色谱行为。     

非常规油气藏压裂返排液资源化利用研究

对非常规油气藏压裂返排液的特点、物性及污染指标进行分析,提出采用破胶混凝技术对返排液进行预处理分离,其水相可再配制压裂液用于现场压裂施工。研究了破胶混凝剂及其优化工艺和压裂液再配制技术,评价了再配制压裂液的主要技术指标及性能,并与清水配制压裂液进行对比。结果表明,再配制压裂液具有基液黏度高,抗温性能较强,易于破胶、返排,残渣量较低及防膨性好等特点。该技术能够实现废液资源化利用,达到节能减排的效果。