网格计算及其应用

网络计算给互联网带来了新的活力，它是一种新型的分布计算技术，致力于解决复杂度很高的新应用问题，文中简述了网格计算的定义、体系结构、关键问题、当前几个有代表性的网格系统以及网格应用实例，并分析了风格计算发展趋势。     

Recent developments of high-performance NEOMAX magnets

For further improvement in achieving extremely high magnetic properties of Nd- Fe- B sintered magnets, extensive investigation has been done to densify the magnet up to the theoretical value, to increase the volume fraction of the Nd ₂Fe₁₄B matrix phase, and to achieve a high degree of alignment. By controlling chemical composition and the amount of constituent phases,improving particle size distribution, and adopting the isostatic pressing method to get better alignment of fine particles, we have succeeded in obtaining a high-performance magnet having residual flux density (B_r) of 1.495 T (14.95 kG), maximum energy product [(BH)_max] of 431 kj/m³ (54.2 MGOe), and intrinsic coercivity (iH_c) of 845 kA/m (10.62 kOe).     

Simultaneous HPLC quantification of total cholesterol,tocopherols and β-carotene in Barrosã-PDO veal

A simple, rapid and sensitive procedure for the simultaneous determination of total cholesterol, tocopherols and β-carotene in meat is described. The method involves a direct saponification of the meat, a single n-hexane extraction and the analysis of the extracted compounds by normal-phase HPLC, using fluorescence (tocopherols) and UV–Vis photodiode array (cholesterol and β-carotene) detections in tandem. Rates of recovery of spiked meat samples were 93% for cholesterol, 83–86% for (α-, β- and -γ) tocopherols and 89% for β-carotene. Repeatabilities were high (CV < 6%) for all determined compounds, except for δ-tocopherol. This tocopherol, which is not usually present in meat, showed a much lower recovery percentage (73%) and repeatability (12.8%). This methodology was applied for the quantification of total cholesterol, tocopherols and β-carotene in three muscles (longissimus thoracis, longissimus lumborum and semitendinosus) of the Portuguese traditional Barrosã-PDO veal, obtained from autochthonous calves fed extensively during summer (with the least abundant green pastures) and slaughtered in early autumn (October). Barrosã-PDO veal showed median contents of total cholesterol (0.50–0.56 mg/g) and, depending on the analysed muscle, moderate to high contents of α-tocopherol (3.3–3.9 μg/g) and β-carotene (0.07–0.09 μg/g), suggesting an high sensorial and hygienic quality.     

桥梁高性能混凝土应用

分析比较了混凝土与高性能混凝土的应用情况，介绍了桥梁使用高性能混凝土的必要性和重要性，通过评价高性能混凝土桥梁的寿命、经济性，提出了降低HPC桥梁建设成本的措施。     

Separation of Triacylglycerol Species from Interesterified Oils by High-Performance Liquid Chromatography

Using a 1,3-regioselective lipase as a catalyst, soybean oil and olive oil were interesterified with the short-chain triacylglycerol tributyrin (1,2,3-tributyrylglycerol) to produce mixtures of structured triacylglycerols (SL-TAG). The SL-TAG were purified by column chromatography and analyzed by both normal-phase (silica column; NP_SIL) and reversed-phase [octadecyl silane (ODS) column] high-performance liquid chromatography (HPLC). Individual SL-TAG molecular species were detected by evaporative light-scattering detection, and characterized by mass spectrometry. NP_SIL HPLC successfully separated the newly synthesized SL-TAG into two groups of TAG: one composed of one butyryl group and two long-chain fatty acyl groups (from soybean or olive oil); the second was composed of two butyryl groups and one long-chain fatty acyl group. The SL-TAG species were further analyzed by reversed-phase HPLC which gave a more detailed separation of the TAG species present in the two SL-TAG.     

采用高性能搅拌设施生产适应市场的水泥

在欧洲和世界其它地区，CEMⅠ水泥(渡特兰水泥)日益为CEMⅡ水泥(有几个主要组份的渡特兰水泥)和CEMⅢ水泥(高炉矿渣水泥)所替代。为了满足生产具有特定粒径分布的高质量水泥的要求，现广为采用的不同水泥组分的混合粉磨工艺已经被单独粉磨然后再在高性能均化设施中进行均化的工艺所代替。依据情况不同，可以采用连续或间歇式搅拌机。文章描述了不同工艺技术．并介绍了最近的几个实例：     

反相液相色谱法测定(反)-4-环已基-L-脯氨酸和(反)-4-苯基-L-脯氨酸

采用反相高效液相色谱法分离和测定(反)-4-环已基-L-脯氨酸和(反)-4-苯基-L-脯氨酸.在选定的色谱条件下,(反)-4-环已基-L-脯氨酸、(反)-4-苯基-L-脯氨酸和杂质之间具有较好的分离效果.该方法具有操作简单、快速、准确度和精密度较好,对同一(反)-4-环已基-L-脯氨酸试样多次测定,(反)-4-环已基-L-脯氨酸的日内、日间相对标准偏差(RSD)分别1.55%和0.09%;(反)-4-苯基-L-脯氨酸的日内、日间相对标准偏差(RSD)分别1.94%和1.79%.(反)-4-环已基-L-脯氨酸和(反)-4-苯基-L-脯氨酸的回收率分别为99.80%~100.40%和97.28%~100.00%.     

S-P混杂纤维对混凝土长期性能与耐久性影响

采用对比的试验方法,研究并讨论了钢纤维、聚丙烯纤维及其混杂对混凝土长期性能及耐久性的影响.研究结果表明,用不同尺度、不同性质的钢纤维与聚丙烯纤维按二元混杂以总体积率0.9%掺入高性能混凝土中,明显改善了水泥混凝土的长期性能,90d干缩值减少36.6%,200d徐变度降低45.4%,并可显著提高混凝土的耐久性能,相对渗透系数降低79.03%,氯离子渗透系数降低30.5%.     

高效液相色谱法测定高纯度4-甲基邻苯二酚

研究了用高效液相色谱-反相色谱内标法测定由4-甲酚与低浓度过氧化氢水溶液反应生成的高纯度4-甲基邻苯二酚。色谱条件为:C18反相柱,流动相为V(甲醇)∶V(质量分数为0.2%的乙酸水溶液)=50∶50,紫外检测波长为282 nm,流速0.8 mL/min。4-甲基邻苯二酚的最低检测质量浓度为0.04μg/mL,在0.1～100μg/mL范围内4-甲基邻苯二酚的峰面积与质量浓度的线性关系良好(r=0.999 9)。以对苯二酚为内标物,用内标法检测由4-甲酚与低浓度过氧化氢水溶液反应生成的高纯度4-甲基邻苯二酚含量,用此方法4-甲基邻苯二酚回收率为99.9%～100.2%。     

高性能混凝土外加剂对水泥砂浆力学性能的影响

采用混合水平正交表研究了新型外加剂对砂浆强度的影响.通过掺加不同因子及水平数的新型外加剂成型了16组水泥砂浆试件,测试了3 d和28 d龄期的强度,采用正交设计中的方差分析、试验误差等方法分析表明,高性能混凝土外加剂并不是性能最好的外加剂,不减少用水量的情况下,用高性能混凝土外加剂替代同等质量水泥后,外加剂对强度的影响并不是显著因素.掺量较少的情况下,对混凝土强度的提高不明显,掺量过大,会造成缓凝.掺加聚羧酸减水剂提高强度,高性能混凝土外加剂和减水剂之间存在交互作用.