农村居民点用地混合利用对乡村活力的影响：基于山东省的实证研究

土地混合利用是提高土地利用集约度、激发地区活力的重要途径。本研究构建了农村居民点用地混合利用与乡村活力关系的分析框架,并以山东省为例,运用辛普森多样化指数、多因素综合评价法、相关性检验等探究农村居民点用地混合利用对乡村活力的影响。结果表明：2010—2018年山东农村居民点用地混合利用指数增速高、中、低区（县）的乡村活力指数增速分别为84.70%、60.74%、50.33%,农村居民点用地混合利用增速越快,乡村活力发展越快;2010年山东农村居民点用地混合利用程度低、中、高区（县）的乡村活力指数分别为0.13、0.23、0.29,2018年分别为0.19、0.24、0.38,农村居民点用地混合利用程度越高,乡村活力水平越高;Spearman相关性分析和Kruskal-Wallis检验结果表明,农村居民点用地混合利用程度与乡村活力显著相关,且对乡村活力具有激发作用。研究认为,农村居民点用地混合利用是激发乡村活力的有效途径,这为编制村庄规划、助推乡村振兴提供新思路。     

不同贮藏温度对小黑麦花粉活力的影响

在室温、4℃、-20℃和液氮(-196℃)下贮藏小黑麦的花粉,研究不同温度对新小黑麦1号、3号、4号和5号花粉活力的影响,结果表明:室温条件下保存3 h,小黑麦花粉活力均在80%左右,3~4 h后花粉活力降低很快,7~8h后花粉活力几乎全无。4℃保存可适当延长花粉活力,保存8 h后,新小黑麦1号、5号花粉的活力降低到60%,而3号和4号降低为80%左右。48 h左右花粉活力降至0%。与4℃相比,-20℃保存下不同品种小黑麦花粉活力降低更快,4 h后花粉活力降低到50%~65%,16 h后花粉活力接近0%。液氮超低温冷冻保存下小黑麦花粉活力相对稳定,保存10天后活力仍然很高,其活力相对保持率在92%左右,理论上可以长时间保存花粉。     

核桃不同品种花粉生活力及其贮藏条件研究

[目的]测定核桃不同品种花粉的生活力,并研究其贮藏条件。[方法]采用固体培养基和液体培养基测定维纳、元丰、香玲、丰辉和当地核桃5个品种的花粉生活力,并对贮藏条件进行考察。[结果]固体培养基测定的花粉生活力普遍高于液体培养基0.98%~2.51%。5个品种均在2.5%蔗糖溶液中萌发率高;花粉最适宜的贮藏条件为-20℃、遮光。核桃不同品种的花粉生活力存在显著差异(P0.05);在同一培养基上,维纳花粉生活力最高为12.3%,其次是丰辉、元丰、香玲,当地核桃最低为3.9%。[结论]花粉生活力的测定以固体培养基较适合。同一培养基上,维纳花粉生活力最高。     

Vitality rating of picea abies by defoliation class and other vigour indicators

The study was made to assess the relationship between visually estimated defoliation class and a number of other variables depicting the vitality of Norway spruce (n=50). Variables characterizing crown size and condition were determined on the standing trees. Electrical impedance (an indication of the physiological status of a tree) was measured in the inner bark tissue of the living trees. Shoot growth and needle variables were determined from the detached sample branches. Negative correlations were found between defoliation class and the growth parameters (5‐year height, radial and volume growth of the trunk). Positive correlations were observed between the needle loss class and the abundance of branch damage, secondary shoots and impedance values. 18 variables (defoliation excluded) describing tree size and vitality were summarized in a factor analysis incorporating 5 factors. These were interpreted as 1) vitality, 2) foliage discoloration, 3) tree size, 4) needle number and 5) needle size factors. The tree‐specific score values for the first factor were interpreted as “vitality indices”;. The rank correlation between these score values and defoliation degree was 0.835. This result suggests that the defoliation class and vitality parameters contributing to the first factor give a consistent estimate of the tree condition.     

试用“气韵生动”分析中国古典园林造园艺术

从“气韵生动”这一绘画美学理论的特殊视角来分析中国古典园林的造园艺术，阐述了“气”和“韵”在中国古典园林的具体体现。说明“气韵生动”是中国古典园林的一个重要特征，从这一角度来研究中国古典园林会给我们带来新的启发。     

水稻种子活力综合评价模型的建立

【目的】建立水稻种子活力的数学评价模型 D(x)，旨在为水稻种子活力性状评价、鉴定和遗传改良提供参考。【方法】以 25 份水稻种子为试验材料，通过标准发芽试验、四唑染色鉴定、模拟田间试验和 Q2技术测定水稻种子的多项指标，利用主成分分析结合隶属函数法和多元线性回归对这些指标进行分析，建立种子活力的数学评价模型 D(x)。利用该模型评价不同栽培密度对水稻种子活力的影响。【结果】籼稻的发芽势、发芽率、7 d 芽长、百株鲜质量、田间芽长、田间根长、初始代谢速率（SMR）、萌发启动时间（IMT）、理论萌发时间（RGT）及四唑染色率等指标的平均值均高于粳稻，而 7 d 根长、百株干质量、萌发氧气消耗速率（OMR）的平均值略低于粳稻。在 Q2 检测中，粳稻的 IMT 值、RGT 值等指标则较优。对 13 个水稻种子活力指标进行相关性分析发现，各指标间存在不同程度的相关性，Q2 检测中的 SMR 值与 IMT 值、OMR 值、RGT 值及百株干质量极显著相关，与田间芽长显著相关；OMR 值与 SMR 值、IMT 值、RGT 值极显著相关，与发芽势显著相关。通过逐步回归建立了种子活力综合评价预测模型Y(x)=0.693+0.003X1-0.006X2-0.127X6-0.004X8+0.234X9（R2=0.94），用这 5 个指标得到的活力预测值（Y）与田间出苗率在参试材料之间的次序基本一致，且两者高度相关（r=0.83），说明用该回归方程可有效预测水稻种子活力。【结论】可选择发芽势、发芽率、百株干质量、OMR 值和 IMT 值这 5 个单项指标作为评价种子活力的依据。     

利用相对电导率和茎尖水势预报落叶松苗木生活力的研究

本文对落叶松在不同晾晒时间中茎尖水势，相对电导率及苗木生活力的动态变化过程进行了测定。结果表明：茎尖水势，相对电导率确实能反映苗木遇到逆境后对其生活力的影响，用于预报造林成活率和初期生长量具有极强的可靠性。     

Genetic and non-genetic factors affecting germination and vitality in spring barley seed

Germination of eight spring barley varieties, grown in two years at eight different locations in State varietal trials in the Czech republic, was analysed. All the combinations were tested under optimal conditions for germination as recommended by ISTA and also at low temperatures (5 and 10°C), and underwater stress (- 2 and - 4 bar). Germination under low temperature and water stress was considered as a character of seed vitality. Varieties in nearly all experiments were a significant source of variation and their relative contribution to the total variation was higher for vitality (5.7–38.7%) than for germination (2.0–4.3%). However, the percentage of germination were not related to the percentage of vitality. The location in nearly all the experiments caused the greatest variation and the impact was greater for germination than for vitality. Provenance effects were different for germination and for vitality; grains harvested in the lowland had the highest germination values, but not the highest vitality values. The results should encourage breeding for seed vitality and some reconsideration of provenance effects on seed vitality.     

药剂处理对瓜尔豆种子低温萌发和活力的影响

用不同的药剂分别在20℃、15℃条件下浸泡瓜尔豆种子24h，放入15℃的发芽箱中发芽。结果表明：400ml／kg乙烯利、10mg／kgAMP、20mg／kg6-BAl5℃浸种显著或极显著的提高种子活力，促使种子低温萌发；而20℃浸种时对种子萌发没有显著影响。0．1％水杨酸钠在15℃条件下能显著提高种子的发芽率，较长时间的维持种子活力。0．1％甲醛处理完全杀死种子。20mg／kgIAA20℃浸种、30mg／kg2，4-D15℃浸种抑制种子的萌发。200ml／kgCCC、500mg／kgGA3、0．1mol／LKNO3、25ml／kg肌醇15℃或20℃浸种效果均不明显。     

Effects of acid deposition on Dutch forest ecosystems

Effects of elevated S and N deposition on the solution chemistry of Dutch forest soils are mainly manifested by increased concentrations of Al associated with increased concentrations of SO₄ and NO₄. Presumed critical Al/base cation ratios are often exceeded below 20 cm soil depth. There is also evidence that elevated N deposion during the last decades affected the forest nutrient status and caused large changes in forest vegetation. About half of the Dutch forests have absolute shortage of P and relative Mg deficiencies compared to foliar N contents. Evidence from field studies of a relationship between soil acidification and nutrient imbalances in the soil and the foliage on one hand and the vitality of forests on the other hand is, however, lacking.