Effects of Planting Density and Row Spacing on Grass Yield of Forage Sweet Sorghum(Sorghum bicolor [L.]Moench)

[Objective] The aim was to explore high-yielding cultivation techniques for forage sweet sorghum. [Method[ The effects of planting density and row spacing on plant productivity and grass yield of forage sweet sorghum （Sorghum bicolor （L.） Moench） were compared using split-plot design and LSD method of IBMSPSSStatis- ticsv22. [Result]The planting density and row spacing had important influence on the plant productivity and yield of forage sweet sorghum. The optimum planting density- row spacing combination for plant productivity of forage sweet sorghum was A1B,, i. e., planting density of 75 000 plants/hm2 and row spacing of 40 cm, and the opti- mum combination for yield of forage sweet sorghum was A2B,, i.e., planting density of 225 000 plants/hm2 and row spacing of 40 cm. [Conclusion] This study will pro- vide theoretical basis and technical support for the production practice of forage sweet sorghum.

Response of leaf carbon metabolism and dry matter accumulation to density and row spacing in two rapeseed(Brassica napus L.)genotypes with differing plant architectures

Biological yield indicates the potential for increasing yield.Leaf carbon metabolism plays an important role in the biomass accumulation of rapeseed(Brassica napus L.).Field experiments with the hybrid HZ62(with a conventional plant architecture)grown in 2016–2017,and HZ62 and accession 1301(with a compact plant architecture)grown in 2017–2018 were conducted to characterize the physiological and proteomic responses of leaf photosynthetic carbon metabolism to density and row spacing configurations.The densities were set at 15×10;ha^(-1)(D1),30×10^(4)ha^(-1)(D2),and 45×10^(4)ha^(-1)(D3)(main plot),with row spacings of 15 cm(R15),25 cm(R25),and 35 cm(R35)(subplot).Individual and plant population biomass accumulation was greatest at R25,R15,and R15 for D1,D2,and D3,respectively,for both genotypes.In comparison with D1 R25,the individual aboveground biomass of HZ62 decreased by60.2%,whereas the population biomass increased by 31.9%,and the individual biomass of genotype1301 decreased by 54.0%and the population biomass increased by 53.9%at D3 R15.Leaf carbon metabolic enzymes varied between genotypes at flowering stage.In contrast to D1 R25,at D3 R15 the activities of ribulose-1,5-bisphosphate carboxylase/oxygenase(Rubisco)and sucrose phosphate synthase(SPS)and the contents of starch,sucrose and soluble sugars in leaves were significantly decreased in HZ62 and increased in genotype 1301.The activities of fructose-1,6-bisphosphatase(FBPase)decreased,in consistency with the abundance of fructose-bisphosphate aldolase in HZ62.In contrast,sucrose synthase(Su Sy)activity appeared to decrease in both genotypes,but a significant increase in abundance of a protein with sucrose synthase was found in the 1301 genotype by proteomic analysis.With increased density and reduced row spacing,the expression of most key proteins involved in carbon metabolism was elevated,and enzyme activity and carbon assimilate content were increased in 1301,whereas HZ62 showed the opposite trend,indicating that the compact plant type can accumulate more population biomass with denser planting.

Study on the Relationship of Seedling Density and Line Spacing to Leaf-stem Ratio, DW/FW Ratio and Grass Yield of Forage Sweet Sorghum

[ Objectives ] The aim was to optimize the configuration of seedling density and line spacing of forage sweet sorghum （ Sorghum blcolor （ L. ） Moench） and explore its high-yield cultivation techniques. [ Methods] Effects of such two influencing factors as line spacing and seedling density on the leaf-stem ratio, DW/FW ratio and grass yield of forage sweet sorghum were analyzed by using split-plot experiment design experiment method and LSD method of IBM. SPSS. Statis- tics. v22 stati, stics software. [ Results ~ Seedling density and line spacing had no obvious effect on the leaf-stem ratio and DW/FW ratio of forage sweet sorghum but had obvious influences on the grass yield. Moreover, the optimal combination of seedling density and line spacing for high yield of forage sweet sorghum was A2 B4, that is, seedling density was 225 000 plants/hm2, and line spacing was 40 cm. [ Conclusions] The results provided a theoretical basis and technical support for high-yield cultivation techniques of forage sweet sorghum.

Effects of Planting Density and Row Spacing on Plant Productivity of Autumn Forage Sweet Sorghum in Hebei Province

[ Objective] This study was conducted to investigate the relationship between each of planting density and row spacing and plant productivity of forage sweet sorghum planted in autumn idle land. [ Methods] Using split-plot experiment design experiment method and LSD method of IBM. SPSS. Statistics. v22 statistics software, the effects of planting density and row spacing on plant productivity of forage sweet sorghum planted in autumn idle land were compared. [ Result] The results showed that the planting density and row spacing had important influences on plant productivity of forage sweet sorghum planted in autumn idle land. Moreover, the optimal combination of plant productivity for A1B4 , i. e. ,under the combination of the planting density of 7.5 × 10^4 plants/hm^2 and the row spacing of 40 cm, the fresh weight and dry weight per plant were 654.37 and 147.11 g/plant, respectively. [ Conclusion ] The results provided a theoretical basis for the production of forage sweet sorghum in autumn idle land.

Crown Ratio and Relative Spacing Relationships for Loblolly Pine Plantations

Two loblolly pine (Pinus taeda L.) culture/density studies were established in 1995-1998 across the Lower Coastal Plain and Upper Coastal Plain/Piedmont regions of the southern USA. Each installation contains 12 plots of loblolly pine planted at six levels of density from 741 to 4448 trees/ha in combination with two levels of cultural intensity, operational and intensive. The data from 37 viable installations were used to evaluate the crown ratio and relative spacing relationship of loblolly pine plantations. The effects of planting density, site quality, and cultural intensity on the relationship were investigated with a nonlinear mixed-effects modeling approach. The crown ratio and relative spacing relationship is exceedingly predictable. When loblolly pine plantation stands reached the average live crown ratio of 0.40, a critical point representing a generally acceptable level of tree vigor, the corresponding relative spacing index ranged from 0.11 to 0.20, mainly depending on initial planting density. The information about the crown ratio and relative spacing relationship would be useful for selecting the best intensity and timing of thinning.

Effect of Row Spacing on Seed Isoflavone Contents in Soybean [Glycine max (L.) Merr.]

Soybean isoflavones compounds such as genistein, daidzein, and glycitein have numerous human health benefits including the reduction of risks of cardiovascular diseases, breast and prostate cancers, and menaupose symptoms in women. Understanding the genetic and environmental control of isoflavones accumulation is of great importance for developing new cultivars with high amounts of seed isoflavones. This study was conducted to analyze the effect of row spacing (25 cm vs. 50 cm) on seed isoflavones accumulation using a recombinant inbred line (RIL) population derived from the cross of PI 438489B and “Hamilton” (PIxH, n = 50). The two row spaces generated plant densities of 250,000 plants/ha and 90,000 plants/ha, respectively. Significant differences in soybean seed isoflavones (daidzein, genistein and glycitein) contents have been observed between plants grown in the two different plant densities. The mean daidzein content was 0.03458 μg·g-1 in plants grown in 50 cm row spaces (low plant density), which was significantly higher than its content (0.03019 μg·g-1) in plants grown in 25 cm row spaces (high plant density). Similarly, the mean glycitein content in plants grown in 50 cm row spaces (0.01905 μg·g-1) was significantly higher than its content in plants grown in 25 cm row spaces (0.00498 μg·g-1. Also, the mean genistein content in plants grown in 50 cm row spaces (0.01466 μg·g-1) was higher than its content in plants grown in 25 cm row spaces (0.00831 μg·g-1). These preliminary results are important in guiding farmers and breeders on choosing the best row spaces to grow soybean plants in order to optimize isoflavones contents. Further studies are needed to understand the correlation between seed isoflavones contents and other agronomic traits such as seed yield, protein, and oil contents.

Asymptotic Results for Goodness-of-Fit Tests Using a Class of Generalized Spacing Methods with Estimated Parameters

A class of pseudo distances is used to derive test statistics using transformed data or spacings for testing goodness-of-fit for parametric models. These statistics can be considered as density based statistics and expressible as simple functions of spacings. It is known that when the null hypothesis is simple, the statistics follow asymptotic normal distributions without unknown parameters. In this paper we emphasize results for the null composite hypothesis: the parameters can be estimated by a generalized spacing method (GSP) first which is equivalent to minimize a pseudo distance from the class which is considered;subsequently the estimated parameters are used to replace the parameters in the pseudo distance used for estimation;goodness-of-fit statistics for the composite hypothesis can be constructed and shown to have again an asymptotic normal distribution without unknown parameters. Since these statistics are related to a discrepancy measure, these tests can be shown to be consistent in general. Furthermore, due to the simplicity of these statistics and they come a no extra cost after fitting the model, they can be considered as alternative statistics to chi-square statistics which require a choice of intervals and statistics based on empirical distribution (EDF) using the original data with a complicated null distribution which might depend on the parametric family being considered and also might depend on the vector of true parameters but EDF tests might be more powerful against some specific models which are specified by the alternative hypothesis.

Study on Rational Well Spacing Optimization of Low Permeability Gas Reservoir

The Shanggu gas field is the low porosity and low permeability. Single well controlled reserves, economic limit well spacing and economic rational spacing through different methods are calculated. With the development experience of Su Lige gas field as guidance, the rational spacing of Shanggu gas reservoir is 700m×900m by calculating daily gas production rate and cumulative gas production with different well spacing using numerical simulation method.

Impact of Plant Density on the Formation of Potato Mimitubers Derived from Microtubers and Tip-Cuttings in Plastic Houses

The potato minitubers have been widely used for the elite seed propagation to improve the seed potato system in China. However, little information is available for an efficient production of the minitubers with high plant density in the protected growing conditions like plastic houses. In present research, the minitubers of a wide-grown potato variety, Favorita, were produced with the microtubers from tissue culture and the tip-cuttings of the microtuber plants. Three plant densities, 200, 400 and 600 microtubers or plants m-2 were set up with the randomized block design of 3 replications and the experiment was repeated in 4 seasons in 2009-2010. The canopy development, light interception, dry weight production and partitioning, tuberization and tuber weight were investigated to elucidate the mechanism by which the plant density affects the formation and growth of the minitubers. The results showed that the number of the tubers formed per unite area was in line with the increase in plant density. The difference in leaf area index （LAI） between the plant densities, especially in early stage of the plant growth, resulted in more radiation interception and dry weight producing in higher plant density than in lower one. However, our analysis demonstrated that the conversion coefficient of the cumulative intercepted radiation to plant weight and the dry weight partition rate to the tubers were constant between plant densities, suggesting that less amount of the photoassimilates partitioned to individual tubers is causal for more small tubers in high plant density. A negative exponential curve model, determined by total number of tubers produced per unit area and the mean tuber weight, fitted well to the tuber size distribution pattern. The optimum plant density could be estimated from this model for a maximum production of the minitubers with desired size.

Effects of Planting Density and Cutting Time on Hay Yield and Nutritional Value of Forage Soybean HN389

Forage soybean is an important source of high protein forage.Variety screening and breeding not only can solve the adjustment of agricultural planting structure,but also can provide a large amount of high-protein forage material,and effectively solve the problem of a serious shortage of high-protein forage in herbivorous animal husbandry in China.In this study,the feeding-type soybean strain HN389 was selected as experimental material,with three planting densities of 270000,405000 and 540000 plants•hm^(-2) and three cutting periods of the initial pod stage(R1),the initial grain stage(R2)and the early mature stage(R3)were set to determine the yield and feeding quality,in order to obtain the best planting density and harvest time of the variety.The results showed that in forage soybean strain HN389 at the R1 and R2 stages,plant height increased with increasing planting densities,while fresh and dry weight per plant decreased with increasing planting densities,and there was no significant difference at the R3 stage.The yield of hay at the R1,R2 and R3 stages increased firstly and then decreased with the increase of planting densities,and the yield per hectare was R3>R2>R1.The order of contents of crude protein(CP),neutral detergent fibers(NDF)and acid detergent fiber(ADF)in feeding quality of HN389 were R2>R1>R3,and ether extract(EE)content order was R3>R1>R2,and there was no significant difference among different groups.Two principal components were extracted from five forage indexes including CP,NDF,ADF,EE and fresh grass yield by principal component analysis.The cumulative contribution rate of principal components 1 and 2 was 90.053%,and their characteristic values were 3.617 and 0.885,respectively.After a comprehensive evaluation,harvested at the R3 stage and the density was 405000 plants•hm^(-2),HN389 had the highest comprehensive score of 0.344,yield of 38035.53 kg•hm^(-2),CP,NDF,ADF and EE contents of 17.61%,17.61%,21.54%and 3.81%,respectively.

Explanation of Relation between Wave Function and Probability Density Based on Quantum Mechanics in Phase Space

The main problem of quantum mechanics is to elucidate why the probability density is the modulus square of wave function. For the purpose of solving this problem, we explored the possibility of deducing the fundamental equation of quantum mechanics by starting with the probability density. To do so, it is necessary to formulate a new theory of quantum mechanics distinguished from the previous ones. Our investigation shows that it is possible to construct quantum mechanics in phase space as an alternative autonomous formulation and such a possibility enables us to study quantum mechanics by starting with the probability density rather than the wave function. This direction of research is contrary to configuration-space formulation of quantum mechanics starting with the wave function. Our work leads to a full understanding of the wave function as the both mathematically and physically sufficient representation of quantum-mechanical state which supplements information on quantum state given solely by the probability density with phase information on quantum state. The final result of our work is that quantum mechanics in phase space satisfactorily elucidates the relation between the wave function and the probability density by using the consistent procedure starting with the probability density, thus corroborating the ontological interpretation of the wave function and withdrawing a main assumption of quantum mechanics.

河南省森林固碳量与碳汇价值评估

为了解当前黄河中下游森林固碳量及碳汇价值现状,助力黄河流域生态保护和高质量发展,基于全国森林清查和国土调查数据,以河南省为例,结合蓄积量转换法原理运用改进后的生物量转换因子连续函数法来测算森林固碳量动态变化和碳汇价值。结果表明:河南省森林固碳量由2008年的1.76×10^(8)t上升至2018年的2.78×10^(8)t,年固碳量较高的森林类型为阔叶混和栎类,固碳量按龄级分布状况为幼龄林最大、过熟林最小,森林固碳量的空间格局表现为“西、南高,东、北低”,主要分布在南阳、洛阳和三门峡;森林碳汇价值由2008年的492.47亿元增加至2018年的778.68亿元,年均增长28.62亿元,2018年阔叶混、栎类和杨树的碳汇价值占碳汇总价值的79.93%。针对当前河南省森林建设存在的问题,提出提升森林固碳能力和推动森林碳汇价值实现的建议,可为促进黄河流域高质量发展提供强劲动力。

不同种植密度和行距配置对香蕉产量及品质的影响

为确定香蕉适宜机械化操作的种植密度和行距配置,采用裂区试验设计,以种植密度(P,P1:2190株/hm^(2);P2:2340株/hm^(2);P3:2520株/hm^(2))为主区,行距(R,R1:宽行5.10 m+窄行1.00 m;R2:宽行4.80 m+窄行1.30 m;R3:宽行4.50 m+窄行1.60 m)为裂区,探讨不同种植密度和行距配置对香蕉农艺性状、产量及品质的影响。结果表明:R能显著影响香蕉株高和茎围,P和R对香蕉单产、总产量均有显著影响,P1、P2香蕉单产较P3分别显著提高10.29%、10.88%,P2总产量较P1显著提高6.62%;R3单产、总产量最高,R1单产、总产量最低。分析产量构成可知,R3能提高香蕉商品蕉采收率;P1、P2单果质量较P3显著提高,R3单果质量较R1、R2分别显著提高21.23%、4.44%。P1果指长较P3显著提高,R2、R3间果指长、果指围显著高于R1。P和R对果实可溶性固形物含量均无显著影响。P3可滴定酸含量较P1、P2显著提高,P1、P2的维生素C含量分别较P3显著提高19.38%、15.78%;R3较R1显著提高维生素C含量8.77%。综上所述,宝岛蕉品种种植密度为2340株/hm^(2),宽行4.50 m、窄行1.60 m时,香蕉农艺性状、产量、商品蕉采收率、单果质量、可溶性固形物及维生素C含量最高。

空间柔性阵列天线薄膜阵面制造技术研究

简要阐述了空间柔性天线的进展,分析了空间柔性天线薄膜阵面制造关键技术。研究了薄膜阵面电磁波传输金属薄膜制备技术、薄膜阵面图形化制造技术、薄膜阵面拼接用材料评价、薄膜阵面的裁切技术等。采用磁控溅射技术,通过溅射功率、走带张力、走带速度的调节,在有机柔性薄膜基材上镀制了不同厚度的金属铜膜,实现了有机柔性薄膜基材的表面金属化;利用飞秒激光刻蚀精度高,不损伤柔性薄膜基材的特点,获得了图形化的金属薄膜阵面单元;对3M92号胶带与改性聚酰亚胺胶接材料的拼接强度与耐高低温性能进行了试验对比,发现改性聚酰亚胺胶接材料的强度与耐高低温性能更好,更适合薄膜阵面的拼接;对比了用纳秒激光和飞秒激光裁切的薄膜微观形貌,结果表明,用飞秒激光裁切的切面光滑,无烧蚀与毛刺,适合于高精度薄膜阵面的制造。研究为空间柔性阵列薄膜天线的制造提供了大量的基础数据。

住宅小区理想规模的模型探究——基于共有空间社会密度的视角

住宅小区内共有空间的社会密度会对居民间的邻里交往产生显著影响。为保证住宅小区共有空间资源的数量和品质,在第Ⅲ建筑气候区条件下建立小区模型,对不同类型小区的共有空间进行分析。结果显示,随着小区内建筑平均层数的增加,户均共有空间资源的数量逐渐减少,共有空间的品质在空间尺度、围合度、私密性等维度上显著降低。基于模型研究结果和城市对土地利用的要求,进而提出住宅小区的理想规模为3~4 hm2,住宅平均层数宜为5~8层,而当确有需要建设高层住宅时,住宅平均层数也不宜超过14层。

城市绿地乔木固碳能力及碳抵消效果评估

定量测算城市绿地乔木固碳能力及抵消碳排放,可为森林城市建设的树种选择和配置提供决策支持。基于高清卫星遥感影像数据和有关经济社会统计数据,结合实地调查,利用生物量模型法测算南充市主城区绿地乔木的固碳能力,探讨群落结构与固碳能力的影响;分析抵消城市能源CO_(2)排放的成效。结果表明:1)南充市主城区绿化植被中木本植物共269种,分属76科163属。出现频度最高的为桂花、银杏、黄葛树、天竺桂、樟木、樱花等10个树种。2)各类绿地林分平均密度677±425株·hm^(-2),平均胸径21.01±7.15 cm,平均树高8.52±2.06 m。3)各类绿地碳密度按大小为广场用地>附属绿地>公园绿地>防护绿地;固碳速率最大的是附属绿地(2.54 t·hm^(-2)·a^(-1)),最小的是公园绿地(1.64 t·hm^(-2)·a^(-1))。4)南充市主城区绿地乔木2020年碳固定量为9 347 t,能源CO_(2)总排放量为1 016.55万t,绿地乔木大约抵消城市能源0.09%CO_(2)的排放量。最后,建议南充市在城市森林营建过程中,应优先考虑多树种混合使用,并适时调整群落密度以优化林分结构、改善生境条件,促进林木整体水平的生长,进而提高群落的固碳能力;同时尽量采用近自然、较为粗放的经营方式,以减少碳排放。

结合聚类边界采样的主动学习

主动学习是一种机器学习方法,需要选择最有价值的样本进行标注。目前,主动学习在应用时面临着一些挑战,其依赖分类器的先验假设,这容易导致分类器性能意外下降,同时需要一定规模的样本作为启动条件。聚类可以降低问题规模,是主动学习的一种有效手段。为此,结合密度聚类边界采样,开展主动学习方法的研究。针对容易产生分类错误的聚类边界区域,通过计算样本密度,提出一种密度峰值聚类边界点采样方法;在此基础上,给出密度熵的定义,并利用密度熵对聚类边界区域进行启发式搜索,提出一种基于聚类边界采样的主动学习方法。试验结果表明,与文献中的5种主动学习算法相比,该算法能够以更少标记量获得同等甚至更高的分类性能,是一种有效的主动学习算法;在标记不足,无标签样本总量20%的情况下,算法在Accuracy、F-score等指标上取得较好的结果。

蓝果忍冬硬枝扦插育苗密度效应研究

【目的】通过研究密度对蓝果忍冬硬枝扦插育苗效果的影响,为实际生产中最适应用密度的确定提供理论依据。【方法】以蓝果忍冬1年生萌生枝条为试验材料,于春季萌动前在塑料大棚内设置12个密度处理,以生根、生长、苗木质量和育苗经济性为指标进行密度效应分析。【结果】结果表明:当扦插密度达到200株·m^(-2)之后,随着密度的增加苗木的生根时间拖后,生根期拉长,生根率、成苗率、整齐度、苗木质量和秋季保存率均呈下降趋势;单位面积育苗经济性呈先上升后下降趋势。低密度扦插有利于快速生根、提高生根率和优等苗比率,高密度扦插有利于增加单位面积苗木产量。【结论】当扦插密度300~400株·m^(-2)时具有更好的经济产出,300~350株·m^(-2)更具生产应用经济性。

株行距配置对冬小麦冠层结构、光环境及产量的影响

为明确株行距配置对冬小麦冠层光环境及产量的影响,本试验在大田条件下,以山农28作为供试品种,研究两个密度即150万hm^(-2)(D1)和225万hm^(-2)(D2)和3个行距即10 cm(R1)、15 cm(R2)、20 cm(R3)组配的6个株行距配置处理对小麦叶面积指数、叶倾角、叶片叶绿素含量、冠层光合有效辐射、群体光合速率、产量及其构成因素的影响,旨在优化冬小麦株行距配置,提高单产。结果表明,D1密度下小麦生育前期容易形成良好的冠层光环境,有助于营养物质积累,为高产打下基础;相同行距下开花期小麦群体的光合速率表现为D1>D2,说明D1密度有助于叶片中营养物质积累和向籽粒转移;D2密度下小麦生育后期的冠层光环境优于D1,有助于叶片营养物质的持续供应;R1行距下冠层光环境明显优于R2和R3,能够吸收更多的光能,光合作用能力更强。密度和行距二者互作对小麦产量及其构成因素的作用表现为:D1R1>D1R2>D1R3>D2R1>D2R2>D3R3。综上,调整株行距配置是提高冬小麦产量潜力的重要途径,D1R1株行距配置更有助于形成良好的冠层光环境,能够获得最高产量,为最佳株行距配置方式。

三维高密度电法在浅层精细化探测中的对比研究

为实现工程场地地下结构精细化探测,在研究区开展了工程勘察中常用的四极装置(温纳、施伦贝谢尔、偶极)三种装置类型的三维高密度电法精细化探测对比研究。主要对各装置的三维反演可视化成果及不同方向的切片成果进行了对比分析。研究结果表明:三种装置均能完成浅部地质体的精细刻画,但在数据覆盖范围、探测深度,分辨率等方面存在一定的差异。根据分析结果提出了一种工程场地勘察三维高密度电法野外数据采集装置类型选择方案,对以后三维高密度电法工程实际应用具有一定的参考和指导意义。