Experimental Analysis on Axial Compressive Behavior of R- CFTStub Columns with Prestressed Binding Bars

In order to investigate the effect of prestressed binding bars on axial compressive behavior of rectangular concrete-filled tubular (CFT) short columns, five rectangular CFT short columns, three with prestressed binding bars, one with ordinary binding bars, the other with no binding bars, were constructed and tested under axial compressive loads. The binding bars were made up with high-strength bolts. As used for ordinary binding bars, the high-strength bolts were welded to the steel tube before the column was loaded to axial compressive force. As used for prestressed binding bars, the high-strength bolts were first tensed by screwed screw cap down to bring force to prestress the steel tube and its core concrete, then welded to the steel tube before the column was loaded to axial compressive force. Test results indicate that the bearing capacity and ductility of rectangular CFT short columns are increased by setting binding bars. Compared to ordinary binding bars, the prestressed binding bars can decrease the longitudinal displacements corresponding to ultimate strength, but have little effect on the ultimate strength and displacement capacity after ultimate strength of the columns. The longitudinal displacements corresponding to ultimate strength of the columns decrease with the decreasing of space between binding bars. With the same section width and amount of binding bars, the bearing capacity of the columns improves with the increase of section long-broad-ratio, while displacement capacity after ultimate strength decreases with the increase of section long-broad-ratio.     

进口管壁面轴向开槽消除轴流泵特性曲线驼峰

当轴流泵在小流量工况下运行时,由于叶轮进口的冲角增大,导致在叶轮内产生脱流等不稳定流动结构,降低泵的水力性能。该文采用计算流体动力学分析方法对轴流泵内部流场进行了研究,结果表明:该轴流泵的特性曲线存在明显的驼峰区域,在0.3到0.61倍最优流量工况区间,轴流泵的扬程和效率明显下降。在临界失速工况下(0.61倍最优流量工况),叶片吸力面前缘靠近轮缘处及叶片尾缘靠近轮毂处均出现了脱流;在深度失速工况下(0.45倍最优流量工况),脱流进一步发展,并与来流共同作用形成稳定的涡旋结构,阻塞整个流道。为了提高轴流泵在小流量工况下的水力性能,引入一种轴流泵进口管开槽技术,分析其对轴流泵内部流场的影响及驼峰的改善作用。结果表明:在小流量工况下,轴向开槽可以减小叶轮进口环量和冲角,可以减小叶片背部的脱流,轴流泵的驼峰得到明显的改善。开槽深度是改善轴流泵小流量工况下驼峰的重要因素之一,当槽深与叶轮直径比为0.02时,叶轮内的通道涡几乎完全消除,轴流泵深度失速工况点的扬程、效率分别提高了66%和32%,极大地改善了轴流泵的水力性能。沟槽数目越多,槽长越长,消除驼峰的能力越好,60个沟槽与2/3倍叶轮直径的槽长在其他参数相同的条件下消除驼峰的能力更强。该文可为避免轴流泵内部的失速流动以及消除水力性能曲线上的驼峰相关研究提供参考。     

泵轮轴向振动条件下高速液力耦合器特性

针对泵轮轴向振动条件下高速液力耦合器特性问题,基于RNG k-ε模型、流体体积法(volume of fluid,VOF)两相流模型、动网格技术、压力隐式算子分裂(pressure-implicit with splitting of operators,PISO)算法和变时间步长法对液力耦合器泵轮在轴向振动条件下的内流场进行数值模拟,通过试验完成对模型的准确性验证。分析液力耦合器流道内部两相流动规律以及受力特性,结果表明:与径向振动相比,相同振幅条件下的轴向振动对循环圆内流量脉动和泵轮、涡轮转矩影响较大;额定转速越高,其泵轮、涡轮转矩脉动幅值、轴向力波动范围越大;振动频率越大,泵轮、涡轮转矩偏差越大;轴向振动幅值越大,泵轮涡轮转矩波动范围越大。从减小转矩波动范围和轴向力的角度控制轴向窜动值不应超过0.04 mm较为合适。     

益肺通络颗粒体外抗结核及止咳止血作用研究

目的 研究益肺通络颗粒体外抗结核、止血、止咳作用及对非特异免疫功能的影响,为其临床应用提供实验依据。方法 用人型结核分枝杆菌标准菌株（H37Rv）和临床分离的结核分枝杆菌敏感菌株和耐药菌株,接种于含有不同浓度益肺通络颗粒的培养基中,观察结核杆菌的生长情况;应用剪尾法、毛细管法测定小鼠的出血时间、凝血时间,观察益肺通络颗粒的止血作用;用氨水引咳,观察其止咳作用;通过巨噬细胞碳粒廓清试验,观察其对非特异性免疫功能（廓清指数和校正廓清指数）的影响。结果 益肺通络颗粒在高浓度（0.01~0.2 g/mL）时对结核分枝杆菌有显著的抑菌作用,但随着浓度降低,其抑菌效果也显著减弱,浓度减低至0.025 g/mL以下时抑菌作用不明显;与对照组小鼠出血时间（321.2±34.3）s、凝血时间（135.8±5.1）s比较,益肺通络高剂量组小鼠出血时间（169.5±23.0）s、凝血时间（97.5±3.3）s均显著缩短（P<0.01）;与对照组小鼠氨水引咳的潜伏期（36.4±1.9）s、5 min内小鼠的咳嗽次数（45.9±3.1）次比较,益肺通络高剂量组小鼠氨水引咳的潜伏期（54.1±1.4）s 显著延长、5 min内小鼠的咳嗽次数（22.7±2.2）次显著减少（P<0.01）;且小鼠廓清指数和校正廓清指数较对照组均有显著提高（P<0.01）。结论 益肺通络颗粒具有体外抗结核作用,具有止血止咳和增强非特异性免疫功能的作用。     

Modification of the superficial cervical axial pattern skin flap for oral reconstruction

OBJECTIVE: To describe an extended pedicle flap based on the superficial cervical artery (SCA) for closure of oral defects in dogs. STUDY DESIGN: Anatomic study; in vivo experimental study. ANIMALS: Canine cadavers (13) and 3 dogs. METHODS: The prescapular branch of the SCA was cannulated and perfused with a lead oxide gelatin mixture. The area perfused by 1 SCA was examined as was the rostral extent of the flap. Staged implantation was performed to evaluate flap performance in vivo. In stage 1, the flap was prepared for implantation into the oral cavity. In stage 2, the flap was fully developed to include the 1 degrees, 2 degrees, and partial 3 degrees angiosome of 1 SCA pedicle. The flap was transposed by a bridging incision and a parapharyngeal tunnel into the oral cavity. The flap was used to reconstruct a partial-thickness defect created in the palate. RESULTS: The territory of the contralateral SCA was captured in all cadavers. The full flap reached the level of the canine teeth in all cadavers. In live dogs, necrosis was not observed after implantation into partial-thickness defects and dehiscence was minimal. Loss of pliability secondary to de-epithelialization and staging resulted in a limitation of rostral reach of the flap. CONCLUSIONS: Whereas the flaps did not reach as far rostrally as anticipated, they survived well in the harsh oral environment. The flap may be modified to reconstruct full-thickness palatal defects. CLINICAL RELEVANCE: The extended SCA pattern flap may be adapted for closure of oral defects.     

Axial pattern flap based on the lateral caudal arteries of the tail in the dog: an experimental study

OBJECTIVE: To determine applicability and size limits of an axial pattern flap based on the lateral caudal arteries in dogs to reconstruct caudodorsal trunk skin defects. STUDY DESIGN: Experimental study. ANIMALS: Ten mature, mixed breed dogs. METHODS: The lateral caudal vessels of the tail were incorporated in the flaps of the treatment group (n=5) and were ligated in the control group (n=5). Flaps were rotated and placed into experimentally created caudodorsal skin defects on the trunk. The length and area of tissue that remained viable in each flap were determined. RESULTS: Mean (+/-SD) survival area (222.8+/-32.9 cm2) and length (25.1+/-4.5 cm) of vascularized flaps were significantly greater (P<.05) compared with control flaps (94.9+/-13.4 cm2 and 14.61+/-4.7 cm). Necrosis occurred in all control flaps, resulting in lower percentage flap area (48.8%) and length (47.1%) survival compared with vascularized flaps (78.1%, 77.5%). CONCLUSIONS: Axial pattern flap based on lateral caudal arteries of the tail was successfully elevated and transferred in a single procedure, with 78% survival for closure of large experimentally created caudodorsal trunk defects in dogs. CLINICAL RELEVANCE: Large cutaneous defects of the caudodorsal trunk area in dog could be reconstructed with tail axial pattern flap. Limitations in terms of size and changes in animal appearance have to be considered before flap elevation.     

Effect of Cowpea Hay,Groundnut Hay,Cotton Seed Meal and Maize Meal Supplementation to Maize Stover on Intake,Digestibility, Microbial Protein Supply and Acetate Kinetics in Weaner Lambs

Ten weaner lambs were used in a double 5×5 Latin square design to evaluate the effect of supplementing maize stover (MS) with cowpea hay (CW), groundnut hay (GN), cotton seed meal (CSM) or maize meal (MM) on the intake, digestion kinetics and acetate clearance rate. CW and GN were offered at 30% w/w to MS, while CSM and MM were given at 15 g/kg^0.75 per day. Supplementation reduced (p<0.01) MS intake but enhanced (p<0.01) total dry matter intake. There were no significant differences (p>0.05) in digestibility. However, the estimated ME intake was significantly (p<0.05) improved by supplementation. The estimated microbial protein supply was almost significantly (p<0.06) improved by 22.68%, 5.35%, 17.58% and 47.90% on the CW-, GN-, CSM- and MM-supplemented diets, compared to the control (7.85 g/day). Microbial protein synthesis efficiency was not significantly affected (p>0.05) by diet, and nor were the acetate clearance rates (p>0.05), which averaged 0.0475±0.0078/min. The improvement in ME intake may have been due to a faster flow rate of digesta and a better balance of nutrients in the end-products of digestion. These results demonstrate that small amounts of forage supplements can improve nutrient intake when animals consume low-quality forages and provide a basis for comparing such supplements with bought-in protein and energy supplements.     

枯死木清理对松褐天牛虫口密度影响的观察

针对枯死松木加剧趋势，采取营林技术为基础，及时清理被松褐天牛为害或风折等因素致死的松木。通过三年的枯死木清理，使松褐天牛虫口密度下降29％。     

Anti-Tumor Function of Polysaccharides from Pholiota adiposa Mycelium

Treatment of S-180 tumor-bearing mice with polysaccharide extracted from Pholiota adiposa mycelium resulted in lower tumor weights, increased carbon particle clearance and phagocytic indices, and significantly higher serum levels of TNF-α and IL-2, compared with untreated controls. Our data suggest that the anti-tumor activity of P. adiposa polysaccharide is related to immuno-enhancing activity.     

The Experimental Study on Size Effects on Axial Compression Performances of Reinforced Concrete Column under Repeated Load

The size effects on axial compression performances of reinforced concrete column under repeated load are needed. Specimens were designed and tested in accordance with the relevant similarity, whose geometric dimensions are: 400 mm×400 mm×1 200 mm, 600 mm×600 mm×1 800 mm and 800 mm×800 mm×2 400 mm. The result of the experiment, the failure characteristics, crack development process, strength, peak stress, peak strain and stiffness of various specimens were comparatively analyzed. The results show that, within size range of this test, size effect exists on performances of columns.