施腐植酸量对西芹产量及养分吸收利用的影响

为了探明设施西芹适宜腐植酸施用量,以美国西芹为试验材料,采用随机区组设计,研究了不同腐植酸施用量对设施西芹地上部产量及养分含量、养分吸收量、养分吸收利用率的影响。结果表明：西芹地上部鲜重和干重随腐植酸施用量增加呈先增加后减少趋势,各施肥处理与对照相比鲜重增产率在5.33%～7.78%之间,干重增产率在5.32%～7.89%之间,以H138处理效果最明显,其次是H184处理;增施腐植酸可显著提高西芹氮、磷、钾含量和氮、磷、钾吸收量及氮、磷、钾吸收利用率,以H138处理效果最明显。综合考虑,当地设施西芹适宜腐植酸施用量为138kg/hm2。     

溶解氧和体重对背角无齿蚌耗氧率的影响

采用自制耗氧率测定装置,研究了不同溶解氧(DO)与体重(W)对椭圆背角无齿蚌(Anodonta woodiana elliptica)和圆背角无齿蚌(Anodanta woodiana pacifica)耗氧率(Oxygen Consumption Rate,Ro)的影响.结果表明,椭圆背角无齿蚌和圆背角无齿蚌耗氧率均随体重的增加而降低,呈负相关关系,非线性拟合方程:Ro椭圆=0.58W-0.48(R2=0.963,P＜0.05);Ro圆=26.65W-1.01(R2=0.916,P＜0.05);2种蚌的耗氧率均随水中溶解氧降低而降低,用双曲线模型Ro=DO/(K1+K2×Ro)评估其在低溶氧条件的适应能力,结果显示2种蚌的耐低氧能力随体重的增加而增强,且椭圆背角无齿蚌对低氧环境的调节能力比圆背角无齿蚌强.     

Potassium sorbate effects on citrus weight loss and decay control

Potassium sorbate (PS) is a well-known and widely used food preservative. Among other applications, it is used as a GRAS fungistatic postharvest treatment for citrus, although its use is not free of significant adverse effects. In this paper, we study in detail the efficacy of wax containing increasing concentrations of PS to control Penicillium digitatum decay in citrus fruit, and its effect on fruit weight loss. Decay control and weight loss increased with the concentration of PS in the wax. Wax with typical amounts of 2–5% PS showed poor decay reduction indices (DRI), between 26% and 32%, whereas fruit weight loss increased compared with non-waxed controls. Waxing of fruit reduced weight loss by up to 40%, depending on wax formulation, but the addition of just 2% PS to the wax caused an increase in fruit weight loss of up to 65% compared with the waxed fruit. Similar results were observed for all the types of wax formulations tested. The hygroscopic effects of PS are even more damaging for citrus fruit with leaves. The leaves lose weight very rapidly when PS is added to the wax and they become desiccated in 24 h.We also present the results of a similar study where PS was applied to citrus as an aqueous treatment. When applied in water, PS was far more effective for decay control than when applied in wax, but there was also a considerable increase in fruit weight loss. A treatment combining aqueous PS with Fortisol^® Ca Plus biostimulant completely solved the problem of weight loss, these mixtures being commercially feasible treatments.     

A high-protein, high-fiber diet designed for weight loss improves satiety in dogs

BACKGROUND: Weight-loss programs for dogs are often hampered by increased begging and scavenging behavior that ensues when food intake is restricted. HYPOTHESIS: A diet formulated to contain a high content of both protein and fiber is more satiating than diets that contain only high fiber or high protein. ANIMALS: Six entire female adult dogs (2 Shetland Sheepdogs, 2 Brittany Spaniels, 2 Labrador Retrievers) participated in the satiety studies; 105 adult female dogs of various breeds and ages were used for the palatability studies. METHODS: Three diets (high protein [103 g/1,000 kcal] high fiber [60 g/1,000 kcal] [HPHF]; high protein [104 g/1,000 kcal] moderate fiber [35 g/1,000 kcal] [HP]; moderate protein [86 g/1,000 kcal] high fiber [87 g/1,000 kcal] [HF]) were tested. Voluntary food intake was measured in 5 sequential crossover studies, and palatability was assessed with food preference tests. RESULTS: Protein digestibility was significantly lower for HF (mean +/- SD; 77.7% +/- 2.52%) than for both HPHF (81.1% +/- 0.96%) and HP (81.1% +/- 1.65%) (P < .001). Short-term food intake (food ingested when offered for 15 minutes every hour for 4 hours) was lower for HPHF than for both HP and HF (P = .038). Medium-term intake (food ingested when offered 3 hours after first meal) was lower for both HPHF (27 +/- 22.2 kcal/kg(0.73)) and HF (41 +/- 6.8 kcal/kg(0.73)) than for HP (57 +/- 18.8 kcal/kg(0.73)) (P = .041). Voluntary food intake 3 hours after feeding a restricted meal (25% daily maintenance energy requirements) was significantly lower on the HPHF diet than on either the HP (-51%, P = .0051) or HF (-47%, P = .014) diets. However, there was no significant difference between the energy intake on the HP and HF diets (7%, P = .37). The HPHF and HP diets had equivalent palatability, and both were more palatable than the HF diet (P < .001). CONCLUSIONS AND CLINICAL IMPORTANCE: The HPHF diet had a satiating effect as evidenced by reduced voluntary intake compared with HP and HF diets, and has the potential to lead to greater compliance in weight-loss programs.     

基于熵权法的广东农业专业镇科技创新环境综合评价研究

农业专业镇是广东发展现代化农业的一个重要载体,其科技创新环境建设对农业产业升级与产业机构调整有重要影响。运用熵权法对广东农业专业镇的科技创新环境进行综合评价研究,得出结果：农业专业镇的政府支持环境、市场环境、科技环境、资金环境、产学研合作环境和社会文化环境并不优越。因此,提出“需围绕公共创新服务平台深化政产学研合作,围绕资源和特色产业构建协同创新体系,建立和健全多元化的农业科技创新资金投入机制,推动区域公共品牌建设和服务体系”的对策建议。     

Litter decomposition in primary forest and adjacent fire-disturbed forests in the Gran Sabana,southern Venezuela

Litter decomposition and nutrient dynamic were studied in tall primary forest (TF) and in adjacent slightly fire-affected (MF) and strongly fire-affected (LF) forests of the Gran Sabana, southern Venezuela. The aim of the study was to compare the mass and nutrient loss of litter in undisturbed forest and adjacent fire-disturbed forests growing under the same soil conditions. The results showed no significant differences in the dry-mass reduction among TF, MF, and LF after 1-year of decomposition. At the end of the decomposition period, the mass loss was 31% in TF, 24% in MF, and 25% in LF. With few exceptions, the initial nutrient content of the litter did not show significant differences among the studied forests. The initial litter was poor in nutrients, especially in P, with C/N ratio extremely high, particularly in LF. Both residual P content and C/N ratio were the most effective predictors of dry-mass loss. The general trend in the three studied forests was net N and to less extend P immobilization and release of K, Mg, and Ca. We concluded that during a 1-year period, the decomposition process was similar in undisturbed and adjacent fire-disturbed forests in the Gran Sabana and that the low litter decomposition seems to be mainly controlled by the low chemical quality of the decomposing litter.     

Alkaline weight reduction monitoring of sea-island type polyamide microfiber fabrics

The alkaline dissolution behavior of sea-island type polyamide microfibers were successfully monitored using a cationic dye staining method. Weight reduction behavior of the alkali-treated microfiber fabrics and the treated fabrics stained with cationic dye were investigated in a comparative manner. The termination of dissolution monitored by both methods was also confirmed by scanning electron microscopy.     

荸荠皮果醋减肥效果研究

[目的]考察荸荠皮果醋的减肥降脂效果.[方法]以废弃荸荠皮为原料,经液态表面发酵法制成营养果醋,研究以小鼠试验考察荸荠皮果醋的减肥降脂效果.[结果]试验表明,低剂量的荸荠皮果醋(0.1 ml/d)能明显抑制小鼠体重的增加速度,小鼠生殖器周围脂肪总重和脂肪系数与模型组相比有一定降低,但无显著差异.低剂量荸荠皮果醋对小鼠血清总胆固醇含量降低效果明显,但对甘油三酯降低不明显.中剂量(0.3 ml/d)荸荠皮果醋能明显降低小鼠的生殖器周围脂肪总重和脂肪系数,与模型组相比差异显著,对血清总胆固醇和甘油三酯的降低均起到明显效果,分别降低了25.2％和26.1％.高剂量组减肥效果良好,但与中剂量组无显著差异.[结论]荸荠皮果醋具有一定的减肥降脂功能,有望成为一种时尚减肥食品.     

Optimum manufacturing conditions of activated carbon fiber absorbents. II. Effect of carbonization and activation conditions

In this paper, viscose rayon-based knitted fabrics were utilized as the precursor to produce activated carbon fiber absorbents (ACFA). The effects of carbonization and activation conditions on characteristics (ACFA) were examined. Experimental results revealed that increasing the flow rate of environmental gas N₂ and steam activator used in conjunction and decreasing the production rate of ACFA can obtain better pore properties. However, higher flow rate of steam activator and lower production rate of ACFA reduced the weight yield. According to our findings, to maintain good absorption property of ACFA, the optimum manufacturing conditions are flow rate of gas N₂ at 80 cc/min, flow rate of steam activator at 60 ml/min, and production rate of ACFA at 30 cm/min, with flame retardant reagent concentration maintained at 30%. Under these conditions, the weight yield can be up to 40.85% and the BET surface area can exceed 1500 g/m².     

甲基丙烯酸甲酯在真丝上接枝共聚反应条件的优化

对有引发剂和无引发剂存在时甲基丙烯酸甲酯对真丝接枝增重的工艺条件进行研究,并用正交试验法探讨了不同的温度、时间、单体质量浓度等对接枝增重效果的影响。有引发剂的接枝聚合反应最佳工艺条件为反应温度80℃、单体质量浓度50g/L、反应时间40min;反应温度和单体质量浓度对接枝率的影响极其显著,反应时间对接枝率的影响不显著。无引发剂的接枝聚合反应最佳工艺条件为反应温度80℃、单体质量浓度55g/L、反应时间3h,反应温度对接枝率的影响极其显著,反应浓度对接枝率的影响比较显著,反应时间对接枝率的影响不显著。