黑膜全膜双垄栽培陇薯10号原种产量与氮磷施用量及密度的关系研究

为了研究半干旱地区黑膜全膜覆盖双垄栽陪下氮肥施用量(X1)、磷肥施用量(X2)和播种密度(X3)对陇薯10号原种产量(Y)的影响,通过试验建立了回归方程:Y=48.47-2.92X12-2.65X32-3.91X2X3,对方程的分析表明,陇薯10号原种目标产量大于30 t/hm2的栽培方案是:施N129.79~170.27 kg/hm2、P2O5117.10~152.90 kg/hm2,播种密度为49 583~55 417株/hm2。     

析因试验的调优技术

根据析因试验寻找最佳响应点的原理,以橡胶树幼苗对硫~(35)的吸收试验为例,应用SAS计算程序,阐明响应曲面分析法的全过程。     

大垄栽培条件下的土壤环境与马铃薯产量

试验进行了大垄与小垄两种栽培模式下的一些土壤环境因子及马铃薯产量的差异研究,结果表明:大垄栽培改善了结薯区及根区的土壤生态环境,使该区的土壤容重和出苗后10￣25cm耕层土壤温度显著降低;使20￣30cm土壤含水量显著地增加;促进了养分释放;大垄栽培相对于小垄使马铃薯总产量和商品薯产量明显增加,且均达到极显著水平。大垄栽培使总产增加24.31%,商品薯产量增加得更大,达到61.74%。大垄栽培是可以在黑龙江省大范围推广的栽培方式。     

大麦新品种蒙啤麦6号的选育及栽培技术

蒙啤麦6号(原代号11PJ-005)为内蒙古自治区农牧业科学院作物育种与栽培研究所通过杂交育种培育的新品种,2019年9月通过非主要农作物品种登记审核。经品系鉴定、品系比较、区域试验及生产示范,均表现高产、优质、酿造品质好等特点。蒙啤麦6号属春性二棱皮大麦中熟品种,生育期66~90 d,株高56.0~84.4 cm,穗长7.1~7.5 cm,主穗粒数20~24粒/穗,千粒质量40.9~54.9 g,籽粒蛋白质含量11.7%。该品种中抗条纹病、网斑病,高感根腐病,抗倒性强,适宜在内蒙古及邻近省份春季种植。     

两系亚种间杂交稻赣亚1号的选育与应用

赣亚1号是江西省滨湖农科所用广亲和籼型光温敏核不育系培矮64S与粳型恢复系Hb-01配组选育而成的两系亚种间杂交稻新组合，是目前国内亲缘关系最远的实用型亚种间组合。2001年12月通过江西省科技厅组织的成果鉴定,2002年2月通过江西省品种审定委员会审定。该组合具有株型理想、产量高、米质较优、抗性强、耐肥抗倒、弱感光、易制种、适应性广等特点，适宜在长江流域作中稻栽培。     

What makes fisheries data informative?

Informative data in fisheries stock assessment are those that lead to accurate estimates of abundance and reference points. In practice, the accuracy of estimated abundance is unknown and it is often unclear which features of the data make them informative or uninformative. Neither is it obvious which model assumptions will improve estimation performance, given a particular data set. In this simulation study, 10 hypotheses are addressed using multiple scenarios, estimation models, and reference points. The simulated data scenarios all share the same biological and fleet characteristics, but vary in terms of the fishing history. The estimation models are based on a common statistical catch‐at‐age framework, but estimate different parameters and have different parts of the data available to them. Among the findings is that a ‘one‐way trip’ scenario, where harvest rate gradually increases while abundance decreases, proved no less informative than a contrasted catch history. Models that excluded either abundance index or catch at age performed surprisingly well, compared to models that included both data types. Natural mortality rate, M, was estimated with some reliability when age‐composition data were available from before major catches were removed. Stock‐recruitment steepness, h, was estimated with some reliability when abundance‐index or age‐composition data were available from years of very low abundance. Understanding what makes fisheries data informative or uninformative enables scientists to identify fisheries for which stock assessment models are likely to be biased or imprecise. Managers can also benefit from guidelines on how to distribute funding and manpower among different data collection programmes to gather the most information.     

乙纶经编网片断裂强力特性研究

本研究以国家有关测试标准为依据，采用裂区模型实验设计方法对多种系列乙纶单丝经编网片测样进行测定，数据采用多元方差分析方法，分析了网片纵横向之间、干湿态之间的断裂强力和断裂伸长率的差异性，找出了影响网片断裂强力和断裂伸长率的主要因素，分析了各主要因素影响的程度和趋势，回归各因素与断裂强力和断裂伸长率间的关系。研究分析结果表明，乙纶经编网片的断裂强力和断裂伸长率均与目脚总丝数、编织密度和成圈丝数有高度显著的线性关系。     

High density flow-through culturing of brine shrimp Artemia on inert feeds — Preliminary results with a modified culture system

A modified filter system is described for the intensive culturing of Artemia in a continuously renewed medium. Extrapolated to a 1 m³ tank, 25 kg live weight Artemia could be produced over a culture period of two weeks on a diet of micronized and defatted rice bran using the salt enriched effluent of an abandoned geothermal well as a culture medium.     

濒危物种─—新疆大头鱼的生态和资源调查与保护对策的研究

１９９２年起对濒危物种──新疆大头鱼的生态进行了调查。调查的水域有：叶尔羌河、阿克苏河及其上游托什干河和库马里克河、塔里木河、博斯腾湖及上游开都河和天鹅湖、大西海子水库、渭干河水系及克孜尔水库和车尔臣河及新发现的喀依拉克湖等水域，行程１００００多ｋｍ。初步查清了新疆大头鱼的分布范围、生态要求及其数量演变。新疆大头鱼分布的海拔高程为８００～１２００ｍ之间，最高不超越１５００ｍ。栖息于水温较高的静水或缓流的湖泊中，仅为了产卵进行短距离的溯河徊游。现存有新疆大头鱼的水域仅为阿克苏河下游的艾西曼湖群、车尔臣河的喀依拉克湖和渭干河水系的克孜尔水库，并在库区下的河道中发现幼体。目前新疆大头鱼物种已极度濒危。新疆大头鱼系裂腹鱼亚科中生长快、个体大、性成熟年龄晚、繁殖力低的大型食肉性鱼类。运用Ｖｏｎ．Ｂｅｒｔａｌａｎｆｆｙ的理论生长方程求得的生长参数：－Ｋ＝０．０６３；ｔｏ＝０．２７５；Ｌ＝１１８．２ｃｍ；Ｗ＝２５８８４ｇ；ｔｉｐ＝１７．１龄；ｔｍａｘ＝４７．２龄。与历史上捕获的最大个体基本一致。并对新疆大头鱼的食性、繁殖、及其生态环境进行了初步研究。新疆大头鱼濒危的原因：１、新疆大头鱼生物学特性的本身决定它对环境要求苛刻     

杨木屑低浓度硫酸中温预处理提取木糖及其发酵

低酸中温预处理可选择性地水解溶出杨木屑中的木糖.正交试验结果显示,影响木糖提取得率的强度顺序为反应温度、固液比、反应时间和硫酸质量分数,影响抑制物产量的主要因素为反应温度和固液比,硫酸质量分数和反应时间的影响较弱.在预处理过程中生成的主要抑制物为乙酸,其次为甲酸和糠醛.基于技术经济分析,可采用100℃、2.0％硫酸、固...