温室生草对南疆桃叶片、果实质量的影响

为研究生草对南疆温室桃叶片、果实品质及产量的影响,通过在温室桃园行间生草,设置间种小黑麦（triticale,T1）、间种三叶草（trifolium,T2）和清耕（CK）3个处理,运用模糊数学隶属函数法对桃树叶片、果实品质和产量指标进行综合评价,筛选出最优处理。结果表明,温室桃园间种小黑麦和三叶草均能使桃树叶面积增大,叶片变厚,叶绿素含量和叶片养分增加。与CK相比,T1和T2处理的桃树叶片厚度分别增加了0.21和0.02 mm,总叶绿素含量分别增加了0.27和0.10 mg·g^-1,叶片全钾含量分别增加1.40和0.26 g·kg^-1。生草间种还能显著提高果实单果重、维生素C含量、可溶性糖含量以及可溶性固形物含量。与CK处理相比,T1和T2处理的单果重分别提高了14.80和10.28 g,可溶性固形物含量分别增加了1.63%和1.26%。生草间种也提升了桃树结果枝的坐果率,增加了单位面积产量。整体看,温室桃园间种小黑麦在改善果实品质和提高产量的效果优于间种三叶草,研究结果可为南疆温室桃的优质栽培生产提供理论支持。     

我国小麦产业发展情况及国际经验借鉴

小麦作为三大主粮之一,在保障粮食安全和稳定国家经济发展中具有重要的作用。立足于国内,从小麦面积和产量波动、生产区域分布、品种演变、小麦品质以及供需形势等几个方面分析了我国小麦产业发展情况,并结合美国、澳大利亚、法国等发达国家小麦产业发展特点,概括总结国外小麦产业发展的先进经验。结果表明：我国小麦供给总量基本充足、小麦优势产区基本形成、小麦品种由稳产为主逐步向高产优质多抗转变、小麦需求向优质专用小麦转变。但存在小麦种植面积小而散、多品种混种普遍、产品结构不合理、产业体系和社会化服务体系不完善等问题。借鉴发达国家的经验,我国小麦产业在今后发展中应加强基础建设,引导形成集中连片种植,落实优质小麦“专种、专收、专储、专用”,以需求为导向引导规范种植、健全农业社会化服务体系。     

绿肥翻压与氮肥减施对水稻产量、品质及土壤肥力的影响

为探明绿肥山黧豆种植翻压下减量施用化学氮肥的潜力,通过3年田间定位试验,设置冬闲+100% N肥（常规施肥,CK）、山黧豆+60% N肥（GM+N60）、山黧豆+70% N肥（GM+N70）、山黧豆+80% N肥（GM+N80）、山黧豆+不施肥（GM）和冬闲+不施肥（NF）共6个处理,研究不同处理对水稻产量、品质及土壤肥力的影响。结果表明,与CK相比,山黧豆与氮肥减量配施能提高水稻产量,GM+N70和GM+N80处理显著提高水稻产量,分别增产13.84%和7.25%;且能提高稻米糙米率、精米率、整精米率和蛋白质含量,降低垩白度及垩白粒率和直链淀粉含量。其中,GM+N70处理的整精米率最高,为78.02%,垩白粒率最低,为18.11%;GM+N80处理的直链淀粉含量最低,为14.26%。山黧豆与氮肥减量配施能明显提高土壤有机质、全氮、碱解氮和速效钾含量,对土壤有效磷含量无显著影响。综上,种植翻压山黧豆与氮肥减量20%~30%配施有利于提高水稻产量、品质及土壤肥力,为构建四川稻区山黧豆种植翻压还田后科学施用氮肥提供理论依据。     

基于主成分分析评价园林小菊资源在西宁地区的适应性

为筛选适宜在西宁地区栽培推广的园林小菊资源,选取7份金陵系列园林小菊资源,通过测定菊花的表型性状及生理生化指标,采用相关分析、主成分分析、综合评价和聚类分析对7种园林小菊资源在西宁地区的观赏性和栽培适应性进行了评价。结果表明,7份菊花资源的株高、主茎粗、叶长、叶宽、叶重、花朵数、单花重、花层数、花径和冠幅的变异系数为28.80%~35.43%。相关分析表明,株高与冠幅、花层数与叶绿素a和叶绿素b含量间存在极显著正相关关系。主成分分析提取到3个主成分,第1主成分为“光合色素因子”,主要包括叶绿素a和类胡萝卜素含量;第2主成分为“花器官因子”,主要影响因子为花层数和花径;第3主成分为“植株形态因子”,主要包括株高、冠幅和叶长。聚类分析将7份菊花资源分为三类：第一类包括‘金陵赤心’和‘金陵红荷’,表现为叶绿素含量较低、植株较矮小、主茎较粗、叶片较重;第二类包括‘金陵潋滟’和‘金陵月桂’,表现为植株高大、冠幅宽大、花层数较多;第三类包括‘金陵玫瑰金’、‘金陵笑靥’和‘金陵阳光’,表现为花层数多、叶绿素含量较高。对7份资源进行综合评价（F值）,排名由高到低依次为：‘金陵玫瑰金’>‘金陵红荷’>‘金陵笑靥’>‘金陵阳光’>‘金陵赤心’>‘金陵潋滟’>‘金陵月桂’。综上所述,“光合色素因子”和“花器官因子”可作为适应性评价重要依据。‘金陵玫瑰金’和‘金陵笑靥’综合表现优异,在西宁地区具有较强的适应性,为菊花品种适应性评价及栽培技术提供了重要参考。     

Strategies for further development of aquatic feeds

ABSTRACT: To date, aquatic feeds have depended heavily on fishmeal and fish oil as their source of protein and lipid. However, the feed industry is encountering shortfalls in the availability of these ingredients because of a decline in the number of fish captured in the wild and the increased human demand for some of the species currently being used for fishmeal and oil production. Therefore, efforts are now being directed in different parts of the world to finding alternative quality ingredients, which ideally are less expensive and readily available for use in practical diets. The data accrued have shown that a large proportion of both fishmeal and fish oil can be replaced by other protein and lipid sources. However, it is emphasized that an optimal essential amino acid balance be maintained and that the n-3 highly unsaturated fatty acid requirement be satisfied when combining economical protein and lipid ingredients. Newly developed feeds should aim at being nutrient-dense in order to reduce the output of solid, P and N waste. This can be done through improving nutrient availability, optimizing the digestible protein to energy balance of the diet, and replacing dietary fishmeal with alternate ingredients. These diets should also be effective for maintaining good health and improving disease resistance in fish through enhancement of immune responses. A wholesome approach to culturing fish would be to use appropriate feeding standards that are aimed not only at improving economic returns but also at developing a lasting cohabitation of sustainable aquaculture and a cleaner environment. Furthermore, in the 2lst century aquaculture would still retain its place as a prominent source of food protein, signifying that fish feed research remains a forceful area in discovering better feeds for the industry.     

罗氏沼虾育苗循环水处理技术与模式

将育苗用水经消毒及沉淀处理后作为试验基础用水,应用泡沫分离器、经预处理的生物滤器和紫外线消毒器等处理罗氏沼虾育苗循环水,使水质得到了有效控制。试验期间,对照池以大量换水及用药等传统方式维持水质,而试验池未曾用药和换水,较对照池节约水67.5%;试验池主要水质指标变化范围如下:NH3 Nm:0～0.010mg·L-1,NO2- N:0.01～0.63mg·L-1,pH:7.48～8.37,CODMn:5.42～12.25mg·L-1,细菌总数:(4.2～130)×103cell·mL-1,弧菌数:(0.2～20)×102cell·mL-1;试验组出苗率为40%,高出对照组33.3%。生产性育苗试验中,试验池与对照池均获得了30%的出苗率。据试验结果及罗氏沼虾育苗特点,提出了处理罗氏沼虾育苗循环水的技术与模式。     

Effects of crushed conspecifics on growth and survival of Penaeus monodon Fabricius post larvae

In the present study, the hypothesis tested was that Penaeus monodon post‐larvae (PL) experience lower growth when exposed to crushed conspecifics, which was achieved by exposing individual P. monodon PL with abundant food for 4 weeks to a gradient from 0 to 100 crushed conspecific PL L^?1. Both dry weight (48.5±7.2 mg) and body size (28.0±1.3 mm) of animals exposed to 1 macerated PL L^?1 were significantly (P≤0.011) higher than those of animals in treatments with 0, 5 and 10 crushed PL L^?1 (average over treatments: 25.6±3.2 mg; 23.4±0.5 mm). All animals died within 1 week when exposed to 70 and 100 crushed PL L^?1, and within 3–4 weeks when exposed to 50 and 30 crushed PL L^?1. Exposure time affected mortality and it appeared that LC₅₀ values decreased from 60 to 13 crushed PL L^?1 from 1 to 4 weeks' exposure. Survival of P. monodon PL was negatively correlated to pH, biological oxygen demand, ammonia and nitrate. In conclusion, low dose of crushed conspecifics has a stimulatory effect on P. monodon PL, as larvae were heavier and larger, while high doses cause high mortality.     

池塘闭路循环水养虾的研究

阐述了池塘闭路循环水水质的变化及养虾效果,循环水开机4h后,氮氮和化学耗氧量,分别降低了11.09％和17.35％,下层水的溶解氧含量比对照池提高了1.22ml/L,并使上、下水层的水温和pH值趋向平衡。生产应用试验证明,使用闭路循环水比对照池的成活率提高了7.78％,降低投饵系数12.18％,提高产量19.21％,每公顷增加效益6354元。     

对虾养殖中新生残饵耗氧动态及其规律的研究

本文根据实验模拟研究的结果，估算了由配合饵料和贻贝肉形成残饵后３６天时间内的耗氧量，并讨论了其耗氧动态和规律。残饵耗氧量的变化范围为４．０９～１７．６１ｇ／ｋｇ·ｄ。残饵耗氧曲线随残饵形成时间的不同而显著变化，且始终呈二次曲线衰减形式，在其演变过程中，该二次曲线方程的二次项系数由负数逐渐演变为正数，并最终接近于污染虾塘底质的耗氧曲线。配合饵料和贻贝肉的耗氧曲线变化形式相近，但程度上存在较大差异。另外，本文还初步探讨了残饵的耗氧高峰期，估算了残饵在虾塘底质总耗氧量中的作用。     

高密度纤维板数控雕刻加工工艺研究

本文以高密度纤维板为原料,采用正交试验探究雕刻工艺对产品质量的影响,得到在该试验水平范围内最优雕刻工艺参数:主轴转速为24000 r·min-1,路径间距为0.20 mm,加工速度为6000 mm·min-1.为数控雕刻在高密度纤维板上应用提供了参考和技术支撑.