采用计算机视觉进行孵化鸡蛋成活可能性的自动检测

本研究将计算机视觉技术与遗传神经网络相结合,建立一套适合于孵化鸡蛋可成活性自动检测的计算机视觉系统,通过计算机视觉技术获取了孵化鸡蛋的角度直方图,并提取了孵化鸡蛋表面颜色特征,采用遗传算法优化了多层前馈神经网络的拓扑结构与权值,提高了神经网络的学习质量和学习速度,实现了孵化鸡蛋可成活性的自动检测,实验结果表明,该方法准确率较高,并具有鲁棒性和高速度。     

三峡库区耕地土壤肥力特征及对策研究

三峡库区土壤肥力差异明显。主要土壤类型紫色土、水稻土、和黄壤,肥力水平差异较大,全量、有效态含量在不同土壤类型不一致。沿江从上而下,全N、全P、有效P含量较稳定,全K、有效K、碱解N含量变化较大。不同土壤类型肥力比较结果表明全N、全P含量为黄壤>水稻土>紫色土;全K、碱解N、有效P、有效K含量为紫色土>黄壤>水稻土。不同区县土壤肥力相关性分析表明全N、全P具有显著相关性,碱解N、有效P、有效K相互之间无相关性。主要土壤类型相关性分析表明水稻土、黄壤中全N同碱解N具有显著相关性。在不同区县和不同土壤类型土壤肥力指标有较大差异,因此在施肥水平上应区别对待。     

浙江慈溪耕地土壤肥力变化研究

调查分析了慈溪市土壤肥力现状,并与第二次土壤普查(1981年)情况作了比较。表明慈溪市土壤有机质和碱解氮含量不高,速效磷较丰富,但存在着不平衡性,速效钾相对较低,特别是旱地土壤;滨海盐土和水稻土分别缺乏微量元素锌和硼;滨海盐土及部分设施栽培土壤的盐渍化威胁着作物生长。根据上述情况,提出了合理施肥及改良利用的建议。     

皖南红黄壤地区连续施用磷钾肥对油菜产量、养分吸收及土壤肥力的影响

在皖南红黄壤地区利用大田试验研究了连续施用磷钾肥对油菜产量、养分吸收和土壤肥力的影响。结果表明:在施用氮肥的基础上合理配施磷钾肥,促进了油菜的生长发育,提高了油菜植株的养分含量和养分吸收量,从而显著增加了油菜的产量,并且磷肥的增产效应大于钾肥效应,三季油菜平均产量以处理P90K120最高,达到了1968.7 kg hm-2;同时连续施用磷钾肥能够改善土壤养分含量,显著提高了土壤速效钾、速效磷含量,与试验前土壤相比,速效磷增加了14.83~20.2 mg kg-1,速效钾增加了69.51~109.61 mg kg-1。     

Robust forecasting of mortality and fertility rates: A functional data approach

A new method is proposed for forecasting age-specific mortality and fertility rates observed over time. This approach allows for smooth functions of age, is robust for outlying years due to wars and epidemics, and provides a modelling framework that is easily adapted to allow for constraints and other information. Ideas from functional data analysis, nonparametric smoothing and robust statistics are combined to form a methodology that is widely applicable to any functional time series data observed discretely and possibly with error. The model is a generalization of the Lee-Carter (LC) model commonly used in mortality and fertility forecasting. The methodology is applied to French mortality data and Australian fertility data, and the forecasts obtained are shown to be superior to those from the LC method and several of its variants.     

甘蔗土壤科学及甘蔗农业生态

本文旨在从保肥,供肥,土壤酸化土壤结构坏变来从旱地,沙田,咸田,基塘地,地膜覆盖蔗地五大农业生态系统蔗区分别比较阐述其问题和解决途径。     

How an Ant Manages to Display Individual and Colonial Signals by Using the Same Channel

Cuticular hydrocarbons are used by some ants to discriminate nestmates from nonnestmates. Every member of the colony bears the same pattern because they are continuously exchanged among nestmates. The postpharyngeal gland (PPG) stores the blend of hydrocarbons and is involved in the distribution of this common mixture. However, some individuals might display individual information on the cuticle (such as a chemical signal of fertility) that must not be mixed within the common pool. We investigated how this paradox is solved in the ant Pachycondyla goeldii by analyzing the nature and localization of colonial and fertility signals. Workers in a queenless condition showed a dominance hierarchy that was correlated with ovarian development. Hydrocarbons from the cuticle and the PPG analyzed by gas chromatography (GC) and identified by GC-mass spectrometry showed a clear discrimination among colonies, supporting the involvement of the PPG in the colonial identity signal. We identified and selected 11 cuticular hydrocarbons that permitted us to discriminate ovarian development classes and that might function as a fertility signal. They allowed clear colony discrimination as well, which suggests that the two signals (the individual signal of fertility and the common signal of colony identity) can be conveyed by the same compounds. However, the hydrocarbons in the PPG did not discriminate among ovarian developmental classes, suggesting that the portion of variation in the cuticular hydrocarbons constituting the fertility signal is superimposed on the signal of colony identity.     

Cuticular Hydrocarbons Provide Reliable Cues of Fertility in the Ant Gnamptogenys striatula

In ca. 150 species of queenless ants, a specialized queen caste is rare or absent, and mated workers take over the role of the queen in some or all of the colonies. Previously, it has been shown that reproduction in queenless ants is regulated by a combination of dominance behavior and chemical fertility signaling. It is unknown, however, whether chemical signals alone can sufficiently regulate reproduction. To investigate this possibility, we studied reproductive regulation in the facultatively queenless ant Gnamptogenys striatula, a species where dominance behavior is rare or absent. Active egg layers and infertile workers showed qualitative and quantitative differences in their cuticular hydrocarbon profile. Five long-chain methyl alkanes, 3,13- and 3,15-dimethyl pentriacontane, 3,13- and 3,15-dimethyl heptentriacontane, and 3,11,15-trimethyl heptentriacontane occurred only on the cuticles of virgin and mated egg layers. Pronounced quantitative differences were found in a further 27 alkenes; alkanes; and mono-, di-, and trimethyl alkanes. Workers that had recently stopped laying eggs had profiles similar to infertile workers, and mating status did not affect this chemical pattern. We conclude that the cuticular hydrocarbon profiles of G. striatula workers provide reliable information about their current fertility. In the interest of colony productivity, this allows reproduction to be regulated without the use of aggression.     

注射用重组人B淋巴细胞刺激因子受体-抗体融合蛋白对大鼠生育力及早期胚胎发育的毒性作用

目的观察注射用重组人B淋巴细胞刺激因子受体-抗体融合蛋白(RCT-18)对大鼠生育力及早期胚胎发育的毒性作用。方法将SD大鼠随机分为4组,分别经皮下注射RCT-18 129、37、11 mg/(kg.d)和0.9%NaCl注射液,每2 d给药1次。雄鼠连续给药5周、雌鼠连续给药2周后,按雌雄1∶1的比例合笼交配,合笼期为2周,计算交配率。雄鼠继续给药至交配成功,雌鼠继续给药至妊娠第6天。实验过程中观察动物的一般反应、体重及摄食量变化。确定雌鼠受精后处死雄鼠,解剖检查睾丸和附睾等生殖器官。于妊娠第15天解剖孕鼠,综合评价妊娠及胚胎形成和早期发育等情况。结果 RCT-18高、中、低剂量组雌性和雄性大鼠均未出现明显的母体毒性反应。各组大鼠各脏器均未见肉眼可见的异常。各剂量RCT-18对大鼠的交配率、妊娠率、生殖系统脏器重量和系数以及早期胚胎发育均无明显影响。结论RCT-18对SD大鼠的生育力及早期胚胎发育无明显毒性作用。     

长期施肥对棕壤主要酶活性的影响

研究目的是揭示长期施肥对棕壤主要酶活性的影响,为土壤培肥以及合理施肥提供理论依据。研究试材采自沈阳农业大学土地与环境学院棕壤肥料长期定位试验微区,共11个施肥处理。结果表明,土壤转化酶、中性磷酸酶、碱性磷酸酶在玉米拔节期及灌浆期出现两个活性高峰,脲酶在玉米拔节期、过氧化氢酶在玉米大喇叭口期各出现一个活性高峰。长期施用有机肥能够提高土壤过氧化氢酶、转化酶及脲酶活性,降低土壤磷酸酶活性,磷肥能够增强土壤过氧化氢酶及转化酶的活性,氮肥则对过氧化氢酶、转化酶、脲酶具有抑制作用。土壤各种酶之间及酶与土壤养分、玉米产量之间存在显著或极显著相关性。因此合理施肥营造良好的土壤生物化学环境将有利于土壤肥力的保持与提高,为作物的高产稳产提供有利保障。