大型常规丙烯精馏塔塔板数的优化

针对气体分馏装置丙烯精馏塔规模大幅提高的趋势,从回流比、能耗、水力学性能及投资等方面综合分析讨论了塔板数的优化。指出丙烯精馏塔塔板数的优化具有明显的技术经济效果。在目前的技术经济条件下,对于0．6Mt／a的气体分馏装置丙烯精馏塔,推荐采用215块理论塔板。     

关于组合节点类型的分析

随着组合结构在工程中越来越多的应用,组合结构梁柱节点成为设计人员和研究者关注的主要问题之一。目前,已经研发出多种节点形式并应用于实际结构中,取得了较好的效果。综合介绍目前用于实际工程中的组合节点相关类型,从理论研究和实际应用两方面分析其存在的问题和不足之处,并提出改进措施和建议。     

Development of annulus fibrosus tissue construct with hydrogel coils containing pre-conditioned mesenchymal stem cell

Low back pain associated with degenerative disc diseases has been a major health concern that brings suffering to the patients physically and economically.Many existing therapeutic strategies provide shortterm relief of symptoms rather than treatment of the underlying cause.Development of an engineered tissue for disc regeneration is still in its infancy due to the limited autologous healthy disc cell source from the patients.It is also challenging to mimic the complexity of micro-architecture in the native disc tissue that determine their unique structural properties.To date,simple tissue models that mimic the annulus fibrosus(AF)micro-environment for understanding the potential of mesenchymal stem cells(MSCs)in AF tissue engineering are still lacking.In this study,the assembly of a coiled hydrogel microfiber has shown its capability to encapsulate MSCs and create an engineered tissue model that mimics the multiple lamellae of native AF.Using this model,we investigated the potential of MSCs that were previously induced by ascorbic acid(AA).Compared to non-induced MSCs,AA-induced MSCs exhibited significant increase in AF-associated biomarkers during later development in the engineered AF tissue model and also encouraged collagen accumulation through the down-regulated catabolic gene MMP1 and upregulated anti-catabolic gene TIMP1.Furthermore,AA-induced MSCs exhibited a Col2/Col1 ratio closer to that of a native AF tissue.These results suggested that AA-induced MSCs could be a potential cell source for AF tissue engineering and this established tissue model may provide a simple tool for successful AF tissue engineering strategies in the future.     

棉籽蛋白粉的生物脱毒研究

以选育的ＦＢ－２－８菌株［１］,在５４℃±１℃按１０％接种量,将棉籽蛋白粉进行固态厌氧发酵４８ｈ。结果：棉籽蛋白粉中总棉酚被脱毒８０％～９０％,游离棉酚含量＜０．０１％,粗蛋白含量无明显变化,蛋白质中各氨基酸的比例未变。     

Effects of steeping and anaerobic treatment on GABA (γ-aminobutyric acid) content in germinated waxy hull-less barley

Effects of steeping conditions (time, temperature and soaking solution) and anaerobic storage on the gamma-aminobutyric acid (GABA) content in waxy hull-less barley grains during germination was examined. The barley kernel was steeped for 16 h at different temperatures (5, 15 or 35 °C) either in water or in a buffer solution (pH 6.0, 50 mmol/L sodium acetate) and then germinated at 15 °C for 72 h. To reach the optimum water content (36–44 g/100 g) for germination, a longer steeping period was required when steeping temperature was lower (16 h at 5 °C vs. 8 h at 15 °C). At 35 °C for steeping, however, the water content in the grains increased excessively, and thus germination percentage became much less than those at 5 and 15 °C. The GABA content increased with increasing germination time and was higher in the buffer solution than water. These findings indicate that the glutamate decarboxylase (GAD), which is the rate-limiting enzyme for GABA synthesis, is more activated by extending germination at controlled pH (6.0). An anaerobic storage with nitrogen in the dark for the germinated barley grains substantially raised the GABA content: 14.3 mg/100 g after the treatment for 12 h, which was four times higher than that of control sample (3.7 mg/100 g). Overall results suggest that the steeping prior to germination greatly affects the GABA production during the germination of barley, and the anoxia storage with nitrogen after the germination increases the GABA content.     

Weighted aggregation and fuzzy-concept-guided signal resemblance and expansion for video format conversion

In this paper, we propose an efficient deinterlacing method for HDTV that preserves image structures, edges, and details. In the human visual system, the eyes are more sensitive to high-frequency information such as edge details than low-frequency information such as image background. Therefore, averaging low-pass filter results is not effective for image enhancement. The proposed method is a weighted filtering approach that generates a half-pixel 9-by-9 edge-based line average window. We also propose pixel-resemblance- and pixel-expansion-based fuzzy weights, which are assigned using a triangular membership function. Compared to conventional format conversion methods, the proposed method outperforms all benchmarks in terms of both objective and subjective qualities.     

Introduction of internal cysteines as conformational probes in yeast phosphoglycerate kinase

Several mutants of yeast phosphoglycerate kinase, each containingonly one internal cysteine residue, were constructed from asingle mutant devoid of cysteine. These cysteines were introducedas local conformational probes in selected buried positions.The enzyme activity, conformational characteristics and stabilityindicated that the mutations introduced only small perturbationsin the molecule. The folding–unfolding process mediatedby guanidine hydrochloride under equilibrium conditions wasstudied by following the variations in ellipticity and the reactivityof the cysteine residue towards 5,5'-dithiobis(nitrobenzoate).The process was found to be reversible except for mutant C97A,V49C,suggesting that this region located in helix I might be crucialin determining an intermediate on the folding pathway. The transitionsobtained by the two signals did not coincide, indicating thatthe local structures, in several parts inside the molecule,are more sensitive to the denaturant than the overall conformation.     

浅谈南方住宅建筑节能

以可持续发展的观点，审视南方地区住宅建设，建筑节能滞后于建设发展，当引起定足够重视。应提高节能意识，按照地区气候特点，有针对性地采取有效措施以实现建筑节能。强调对自然条件的充分利用；提高围护结构热工性能，采用较高档的节能技术与产品；外窗是夏季隔热最薄弱的环节；活动式外遮阳的效果最为显著；空调设备应选 用能效比较良好的产品等。评价南方地区住宅建筑节能的最终效果是建筑物耗冷量指标等，尚待专门研究。