典型高温年分期播种冬小麦生育及产量性状差异性分析

在2016/2017年度自然高温年景下进行冬小麦分期播种实验,以适期晚播以来冬小麦多年平均播期（10月10日）为对照,设早播10d（E10）、迟播10d（L10）、迟播20d（L20）处理。通过方差分析、卡方检验、最小显著性差异和Logistic方程模拟等方法,对分期播种冬小麦发育期、生长量及产量因素等进行差异性分析,探究冬小麦在全球气候变暖背景下的适播期及其生长发育和产量性状变化规律。结果表明：不同播期处理的冬小麦冬前各发育期差异较大,越冬后随着气温升高,各播期冬小麦发育进程趋于一致;随着播期推迟,冬前积温递减趋势明显,冬小麦株高、绿叶面积和植株密度等生长要素均呈明显降低或减小趋势,冬小麦结实小穗数和不孕小穗数亦呈极显著减少趋势,各播期穗粒数则差异不显著;不同播期冬小麦千粒重差异极显著,其中早播10d处理极显著低于对照,迟播冬小麦处理与对照差异不显著;对照处理冬小麦产量最高;不同播期处理冬小麦灌浆过程均符合Logistic生长规律,对照籽粒渐增期持续时间长于其它处理,利于冬小麦增加籽粒“库容”,籽粒快增期灌浆速率快,利于提高粒重;随着播期的推迟,灌浆速率和持续时间的变化无明显规律,对照处理冬小麦灌浆过程相对稳定。     

比较教学法在焊工工艺学课程教学中的应用

焊工工艺学是培养学生全面掌握中级电焊工工艺技术理论知识的专业课程,其涵盖面广,学生学习吃力,教学难度较大。为使学生全面、彻底地掌握焊工工艺学课程的内容,运用比较教学法授课,收到较好的效果。     

中国长江流域冬麦区小麦品种试验精确度回溯分析

为全面评价长江流域小麦品种区域试验精确度的发展水平,分析了2011—2021年度中国长江流域冬麦区单年单点和一年多点小麦区域试验的试验精确度和品种比较精确度,对产量、穗数、穗粒数、千粒重、生育期、株高、基本苗和最高茎数等性状的试验精确度差异进行了比较。结果表明,长江流域冬麦区单年单点品种试验精确度较好,试验误差变异系数(CEV)在5%和10%以下的试点数占比分别在60%和95%以上,但品种比较精确度(RLSD_0.05)在3%以下的试验比例不到10%,长江上游和中下游单点品种试验RLSD_0.05在10%以下的试点数分别占比约60%和90%。一年多点区域试验精确度和品种比较精确度显著优于单年单点试验,上游和中下游试验平均CEV分别在8%和5%以下。采用试点固定模型时,长江上游和中下游试验平均RLSD_0.05分别为2.19%和1.49%,符合国家小麦品种审定标准对品种比较精确度的要求;但采用试点随机模型时,小麦品种试验尚无法鉴别出品种间3%的产量差异。试验对生育期、株高、基本苗、千粒重和穗数的RLSD_0.05优于产量性状,而最高茎数和穗粒数的RLSD_0.05较低。     

Static home-based versus dynamic mobility-based assessments of exposure to urban green space

There is growing interest in urban green space exposure estimated dynamically by accounting for individuals’ mobility during daily life. We aimed to explore if daily green space exposure estimates based on individuals’ mobility substantially differ from static home-based exposure estimates, and to examine potential effect modification by personal (sex and work status) and temporal (weekends versus weekdays) characteristics. To assess the association between daily exposure to urban green space, we used home address and time-activity data collected from 1911 participants in western New York, US, using their GPS-enabled mobile phones. We abstracted both individuals’ home address based (home-based) and daily time activity based (mobility-based) green space exposures from the Normalized Difference Vegetation Index (NDVI). Then, we assessed the association between mobility-based and home-based exposure estimates using linear mixed effect regression models with subject-specific random effects. We also explored whether this effect was modified by individual-level characteristics, including work status and sex, as well as whether assessments took place on weekdays versus weekends. We found that daily dynamic exposure to urban green space based on individuals’ mobility was not substantially different from static exposure estimates based on one’s residence, but that there were statistically significant effect modifiers. Specifically, the correspondence between mobility-based and home-based exposure to green space was relatively lower for employed compared to unemployed participants, whereas their correspondence during weekends increased compared to weekdays. Our findings suggest that there is a strong correspondence between mobility-based and home-based exposure to urban green space, but that their associations are modified by personal and temporal characteristics. Further research is needed to confirm our finding for general population in other settings, such as different seasons and other regions.     

Some developmental differences inEpinotia granitalis (Lepidoptera: Tortricidae) between two host tree species

To detect developmental differences inEpinotia granitalis in two host tree speciesCryptomeria japonica andChamaecyparis obtusa, the fourth or fifth instar larvae were collected daily from the two species located on the grounds of the National Forest Tree Breeding Center, from April 19 to May 9 in 1994 and April 18 to May 10 in 1995. Larvae ofE. granitalis collected fromC. obtusa had heavier body weight, developed to larger adults than those collected fromC. japonica, and mortality from the fourth or fifth instar larval stage to adults onC. obtusa was lower than that onC. japonica. All these facts suggest that larval performance onC. obtusa was higher than that onC. japonica.     

A reduced growth model based on stand basal area. A case for hybrid poplar plantations in northeast Spain

Whole-stand models normally require data on initial stand basal area and dominant height. Dominant height measurements are time-consuming and often imprecise, compromising subsequent predictions. Poplar plantations provide a special case where basal area correlates with site index; a whole-stand model could thus be based on stand basal area. We report a static model constructed by the generalized algebraic difference approach (GADA) for poplar plantations for three different hybrid poplars (Populus × euramericana (Dode) Guinier “I-214”, “MC”, and “Luisa Avanzo”) in northeast Spain. The transition function was based on current stand basal area and was fitted with data from 158 permanent plots ranging from 1- to 17-year-old plantations. Merchantable stand volume was estimated by a volume equation where height was predicted by a height–basal area relationship based on 458 temporary plots. The model differences between clones were compared using the nonlinear extra sum of squares method. Significant differences were detected, while Luisa Avanzo presented the highest merchantable volume at the end of the rotation. Errors in basal area predictions were below 20% within 6 years in the case of Luisa Avanzo and MC clones, and within 3 years in the case of I-214. Our research showed that satisfactory predictions can be obtained using GADA with a single transition function based on an easily measurable variable such as stand basal area.     

大跨度悬索静力构形和内力计算方法

建立悬索重力曲线方程的差分形式,给出悬索在自重、索端移动、集中力作用下非线性分析的一种简单的有限差分法迭代模型。与有限元方法不同,本方法不需要悬索初始线形,只需要输入悬索两端坐标、索截面面积、弹性模量、初始张力,可计算悬索在不同状态下的张力和线形,算例表明该方法收敛速度快,精度高。     

松木防蓝变和脱色处理技术的研究

解决松木蓝变问题已成为松材加工高档用材的基础和提高松材商品附加值的关键。通过探索性试验和正交试验以及(?)差的分析比较,得到防蓝变的优配方为:0.75％A1 0.50％A3 0.10％B。此配方在试验所观察的10周内防治效力达到了100％。同时,对松木蓝变色斑的脱除研究表明,在浓度5％的C药剂中加入D药剂,调节其溶液的pH值为10左右,加热到50-60℃对板材进行处理可有效脱除蓝变色斑。     

语用失误与大学外语教学

语用失误分为语用语言失误和社交语用失误,是由于母语的影响、文化的差异、不同的价值观念以及教学不当等原因造成的.笔者结合实例分析了语用失误的类型和成因后,提出了在外语教学中克服语用失误应采取的措施.     

不同杨树品种主要经济指标差异性分析

笔者对7a生的20个杨树品种的生长量、形率、材性和树皮厚度等指标进行了差异性分析。结果表明:欧美46、鲁山杨、圣山杨和欧美14在单株材积和木材基本密度显著优于对照(中嘉8号和中潜3号),材积遗传增益为47.50%、34.55%、34.51%和22.05%;胸高形率、绝对形率和正形率的变化范围分别为0.5678～0.6876、0.5211～0.6557、0.5349～0.6661,半常绿杨在形率指标上显著优于其它品种,而其它品种之间没有显著差异;纤维指标和树皮厚度没有显著差异。