Heterosis Estimation for Growth Traits and Wood Properties of Eucalyptus urophylla under Two Sites in Southern China

Heterosis is a quicker,cheaper and easier method for increasing plantation production,and heterosis studies can provide the basis for exploitation of valuable hybrid combinations in breeding programs.Growth traits,wood properties,and bark percentage were assessed for 6×6 full diallel progenies of E.urophylla in southern China measured at age 4 years.Analysis of variance showed that there were significant differences on all studied traits except dynamic modulus of elasticity among combinations.The mean diameter at breast height,wood basic density,and dynamic modulus of elasticity were 9.40 to 12.20 cm,0.45 to 0.47 g cm-3,and 5.04 to 5.72 GPa,respectively.The coefficients of variation ranged from 18.18%to 50.43%for growth traits,9.07%to 55.24%for wood properties and 22.26%to 23.93%for bark percentage.The heterosis estimation on diameter at breast height,wood basic density,and dynamic modulus of elasticity were-24.07%to 18.74%,-14.23%to 9.17%and-25.53%to 16.28%.U22×U56 generally had higher heterosis of growth traits and wood properties through three sites.Same combinations had different original and reciprocal heterosis estimation at two sites even on same traits.The combinations of same parents always had similar original and reciprocal heterosis estimation.

Present Situation of Eucalypts Breeding and Future Prospect in China

Breeding is the major procedure in forest research.The basic goal in all of breeding program is to expand the frequency of favorable alleles or the frequency of specific combinations of favorable alleles in the breeding populations through recurrent selection in order to improve the performance of individual plants.During the past three decades,an increase in research on breeding has improved Eucalyptus productivity,and to some extent our standing of their effects on tree growth and on wood properties.Unfortunately,very little information about breeding on the review of Eucalyptus grown in China has been published even though this species was introduced some 120 years ago.This paper reviews the available information regarding research status and prospect of breeding under Chinese ecological conditions and to outline some suggestions to them.According to the present research situation of breeding,we would recommend that:generalizing empirical and useful practices;developing highvalue products;creating more clones for demand;carrying out intensively research over different species and clones for different cultivation goals at different sites over time;above all,applying breeding strategy,especially for multiple generations and interspecific hybrid breeding.

Conditional selection with CNN augmented transformer for multimodal affective analysis

Attention mechanism has been a successful method for multimodal affective analysis in recent years. Despite the advances, several significant challenges remain in fusing language and its nonverbal context information. One is to generate sparse attention coefficients associated with acoustic and visual modalities, which helps locate critical emotional se-mantics. The other is fusing complementary cross‐modal representation to construct optimal salient feature combinations of multiple modalities. A Conditional Transformer Fusion Network is proposed to handle these problems. Firstly, the authors equip the transformer module with CNN layers to enhance the detection of subtle signal patterns in nonverbal sequences. Secondly, sentiment words are utilised as context conditions to guide the computation of cross‐modal attention. As a result, the located nonverbal fea-tures are not only salient but also complementary to sentiment words directly. Experi-mental results show that the authors’ method achieves state‐of‐the‐art performance on several multimodal affective analysis datasets.

Comparison of thermal and light performance in two typical Chinese solar greenhouses in Beijing

Solar greenhouses have been used for producing vegetables in northern China during early spring,late autumn or over-winter.To improve the thermal performance of solar greenhouses,a traditional type and a retrofitted design were comparatively evaluated.In the retrofitted design,three adjustments were incorporated:the material and structure of the walls,south-facing roof angle,and structure of the north-facing back-roof.The results indicated that the thermal and light performance of the retrofitted greenhouse was much better than that of the traditional greenhouse.Specifically,the daily mean temperature,minimum air temperature,and soil temperature inside the greenhouses after retrofit ting were increased by 1.3,2.4,and 1.9℃,respectively,meanwhile,the daily total solar radiation and PAR were increased by 28.2%and 9.2%,respectively.The wall temperature and its daily variation range were reduced with increasing depth and height.The characteristic analysis of heat storage and release indicated that higher locations have longer heat storage,and shorter heat release time in vertical direction,as well as a lower ratio of heat release to storage.In horizontal direction,the western wall has the shortest heat storage time but the highest heat release flux density.Altogether,the heat storage time of the wall is 1.5 h less than that of the soil.The heat storage flux density of the wall is 1.5 times of that of the soil,but the heat release flux is only 61%of the soil’s value.The total wall heat storage is half of that of the soil in the greenhouse;the total wall heat release amount is only a quarter of that of the soil.Therefore,the thermal environment of solar greenhouses can be further improved by improving the thermal insulation properties of the wall.

Design and optimization on rootstock cutting mechanism of grafting robot for cucurbit

Cutting mechanisms in existing grafting machines are unable to completely cut through the rootstock growth point and can easily damage seedlings.During the mechanical operation of splice grafting,the cutting angle of the rootstock is an essential factor for ensuring the quality and survival rate of grafting seedlings and a stable process for grafting robots.Therefore,in this study,commonly used grafting rootstocks,e.g.,cucurbita moschata,and calabash gourd were used as research objects for studying and analyzing the cutting angle of a splice grafting method.The morphological and structural parameters of the rootstock and scion were measured,and a structural model of the internal cavity of the rootstock was constructed using an image analysis method.The critical cutting angles for the cucurbita moschata and calabash gourd seedlings were obtained.According to the analysis,the grafting cutting angles for cucumber seedlings matching with cucurbita moschata seedlings were 20°and 25°,respectively,and the fitting rate of the cutting surface of the rootstock and scion was 99.04%.A cutting mechanism for the rootstock growth point and geometric model of the cutting operation were established,and the structural parameters of the mechanism and cutting angle adjustment were optimized.A cutting performance test showed that the success rate of the pressing the cotyledons of cucurbita moschata seedlings was 96.67%,and the success rate of cutting was 98%.The cutting accuracy was 96.8%,and the cutting surface fitting rate of the rootstock and scion was 98.61%.The latter differed by 0.43%from the theoretical rate but met the requirements for the splice grafting method.Thus,this study can provide a reference for the design of a cutting mechanism for a grafting robot.

XGRouter： high-quality global router in X-architecture with particle swarm optimization

This paper presents a high-quality very large scale integration （VLSI） global router in X-architecture, called XGRouter, that heavily relies on integer linear pro- gramming （ILP） techniques, partition strategy and particle swarm optimization （PSO）. A new ILP formulation, which can achieve more uniform routing solution than other formu- lations and can be effectively solved by the proposed PSO is proposed. To effectively use the new ILP formulation, a partition strategy that decomposes a large-sized problem into some small-sized sub-problems is adopted and the routing re- gion is extended progressively from the most congested re- git）n. In the post-processing stage of XGRouter, maze rout- ing based on new routing edge cost is designed to further optimize the total wire length and mantain the congestion uniformity. To our best knowledge, XGRouter is the first work to use a concurrent algorithm to solve the global rout- ing problem in X-architecture. Experimental results show that XGRouter can produce solutions of higher quality than other global routers. And, like several state-of-the-art global touters, XGRouter has no overflow.

A framework based on sparse representation model for time series prediction in smart city

Smart city driven by Big Data and Internet of Things(loT)has become a most promising trend of the future.As one important function of smart city,event alert based on time series prediction is faced with the challenge of how to extract and represent discriminative features of sensing knowledge from the massive sequential data generated by IoT devices.In this paper,a framework based on sparse representa-tion model(SRM)for time series prediction is proposed as an efficient approach to tackle this challenge.After dividing the over-complete dictionary into upper and lower parts,the main idea of SRM is to obtain the sparse representation of time series based on the upper part firstly,and then realize the prediction of future values based on the lower part.The choice of different dictionaries has a significant impact on the performance of SRM.This paper focuses on the study of dictionary construction strategy and summarizes eight variants of SRM.Experimental results demonstrate that SRM can deal with different types of time series prediction flexibly and effectively.

Design and experiment on scion cutting mechanism of grafting robot for cucurbit

The scion cutting mechanism of the traditional grafting machine cannot correct the bending degree of the scion seedling stem so that the cutting angle of the scion seedling is not standard and the survival rate of the grafted seedling is affected.In this study,cucumber seedlings and watermelon seedlings were taken as experimental objects.Based on the analysis of the geometric parameters and mechanical characteristics of scion seedlings,a scion cutting mechanism with holding seedling applied to cucumber seedlings and watermelon was designed and developed.The main structure and operating parameters of V-shaped holding seedling block and cutting unit were determined,and holding seedling and cutting performance tests were carried out.The test results showed that compared with the common arc clamp,the V-shaped holding seedling block had a better guiding and centering effect on the scion seedling,could better correct the bending state of the scion seedling stem,and the success rate of holding seedling of the V-shaped holding block reached 98.33%,which was increased by 13.33%compared with the arc-shaped clamp,and the seedling injury rate was only 1.67%.The upper and lower two-point positioning of scion stem by clamping hand and holding seedling block can improve the cutting performance effectively.The cutting accuracy rate of the scion was 97.75%,and the cutting success rate was 98.67%.The cutting performance was closely related to the holding seedling effect.The research results can provide a reference for the design of cutting mechanisms of melon grafting robots.