Search | Engineering

订阅投稿

首页工程期刊工程焦点工程成就工程前沿关于我们 English

资源类型

期刊论文 36

年份

2023 4

2022 5

2021 1

2020 1

2019 2

2018 4

2017 1

2016 3

2015 2

2013 2

2012 4

2011 2

2010 2

2009 1

2006 1

2002 1

展开︾

关键词

棉花 2

21世纪海上丝绸之路 1

BNCT医院中子照射器 1

HY-2A 1

中国油气田开发 1

中子、伽马混合场 1

中子和γ吸收剂量率 1

中子能谱 1

中子通量密度 1

低渗透油田 1

作物病害 1

农业生态工程 1

冶金 1

化工 1

发展趋势 1

变量控制技术 1

合作机制 1

国计民生 1

城市走廊 1

展开︾

检索范围：

排序：展示方式：

Endosulfan residues and farmers’ replacement behaviors of endosulfan in the north-west inland cotton

《环境科学与工程前沿（英文）》 2023年第18卷第4期 doi: 10.1007/s11783-024-1803-8

摘要：

● The situation of endosulfan residues in cotton fields were assessed.

关键词： Cotton fields Endosulfan residues Farmers KAP survey Replacement behaviours

HTML PDF 收藏

INDIAN PERSPECTIVE: SUSTAINABILITY OF BT COTTON IS A MATTER OF CONCERN NOW!

《农业科学与工程前沿（英文）》 2022年第9卷第1期页码 146-149 doi: 10.15302/J-FASE-2021415

HTML PDF 收藏

Simulation of heterogeneous two-phase media using random fields and level sets

George STEFANOU

《结构与土木工程前沿（英文）》 2015年第9卷第2期页码 114-120 doi: 10.1007/s11709-014-0267-5

摘要： The accurate and efficient simulation of random heterogeneous media is important in the framework of modeling and design of complex materials across multiple length scales. It is usually assumed that the morphology of a random microstructure can be described as a non-Gaussian random field that is completely defined by its multivariate distribution. A particular kind of non-Gaussian random fields with great practical importance is that of translation fields resulting from a simple memory-less transformation of an underlying Gaussian field with known second-order statistics. This paper provides a critical examination of existing random field models of heterogeneous two-phase media with emphasis on level-cut random fields which are a special case of translation fields. The case of random level sets, often used to represent the geometry of physical systems, is also examined. Two numerical examples are provided to illustrate the basic features of the different approaches.

关键词： microstructure random fields level sets shape recovery two-phase media

HTML PDF 收藏

我国棉花生产现状与发展趋势

喻树迅

《中国工程科学》 2013年第15卷第4期页码 9-13

摘要：

棉花是我国的重要经济作物，棉花产业的健康稳定发展意义重大，本文简要介绍了“十一五”期间我国棉花科研在基础研究、转基因抗虫棉、现代分子育种体系、品种高效应用保障技术等方面所取得的主要成就，阐述了我国棉花产业面临的总量不足、黄萎病危害和新成灾害虫加重等重大问题，并提出应推进盐碱旱地植棉，扩大粮棉复种指数，加大棉花分子设计育种技术的应用，大力推进棉花全程机械化进程，深入开展“千斤棉”高产创建，大幅度提高单产水平，实现快乐植棉，从而提高我国棉花科技的自主创新能力和棉业国际竞争力。

关键词：棉花生产现状发展趋势

HTML PDF 收藏

Effects of cotton straw amendment on soil fertility and microbial communities

Wuren HUANG, Zhihui BAI, Daniel HOEFEL, Qing HU, Xin LV, Guoqiang ZHUANG, Shengjun XU, Hongyan QI, Hongxun ZHANG

《环境科学与工程前沿（英文）》 2012年第6卷第3期页码 336-349 doi: 10.1007/s11783-011-0337-z

摘要： Maintaining soil fertility, while controlling pollution from excessive chemical fertilizer application is important for keeping soil productivity of sustainable agriculture. Variety of straws have been used and proven to be good soil amendments for increasing soil organic matter (OM) and a range of additional soil nutrients. However, little is known about the utilization of cotton straw for soil amendment. To better understand the mechanism behind cotton straw soil amendments, investigations were performed upon cucumber seedlings, where changes to soil nutrients and microbial communities were investigated. The results revealed that the cotton straw application promoted the cucumber seedling growth by significantly increasing the soil OM, available nitrogen, available phosphorus, and available potassium. The concentration of cotton straw was positively correlated to both the number of the culturable microorganisms and also the total microbial biomass within soil. Furthermore, assessment of cotton straw application using Biolog metabolic profiling and phospholipid fatty acid analysis revealed that such application increased the microbial community metabolic activity, and markedly changed the structure of microbial community. 16S rRNA gene clone library construction and phylogenetic analysis of soil bacteria revealed - Proteobacteria sequences dominated the cotton straw amendment soil, comprising 27.8% of the total number of analyzed sequences, while they were less represented in control soil (13.4%). On the contrary, the Sphingobacteria (7.8%) and Verrucomicrobia (2.4%) in the cotton straw amendment soil decreased after application when compared to the control soil 15.2% and 15.2%.

关键词： cotton straw soil amendments microbial diversity Biolog phospholipid fatty acid 16S rRNA gene clone library

HTML PDF 收藏

Effect of UAV prewetting application during the flowering period of cotton on pesticide droplet deposition

Weixiang YAO, Xianju WANG, Yubin LAN, Ji JIN

《农业科学与工程前沿（英文）》 2018年第5卷第4期页码 455-461 doi: 10.15302/J-FASE-2018232

摘要：

Prewetting process can reduce the contact angle between the droplet and the leaf blade, so that the droplet can more easily wet and spread, thereby increasing the quantity of deposition. To improve the effectiveness of pesticides on cotton leaves, prewetting by single-rotor electric unmanned aerial vehicles (UAV) was studied, focusing on the effects of pesticide deposition on cotton leaves during the flowering period. Cotton leaves in 0°–30°, 30°–60°, 60°–90° leaf blade angle ranges (angle between the leaf blade and the horizontal plane) were examined. In the first experiment, four different prewetting volumes (0, 1.6, 3.2 and 4.8 L) were sprayed by a single-rotor electric UAV on four cotton plots (plots A to D) each with an area of 120 m , and then each area was sprayed with a 0.8% (w/v) ponceau 2R solution by another single-rotor electric UAV. The results revealed that with no prewetting, droplet deposition quantity decreased with increasing leaf blade inclination. After prewetting, the mean droplet deposition quantity on plots B, C and D increased by 39.8%, 9.7% and 24.9%, respectively. The prewetting rate of 1.6 L per 120 m had the most significant effect on improving the deposition of droplets. It was also found that the mean droplet deposition quantity in each leaf blade angle range increased after prewetting. For the leaf blade angle range 60° to 90°, this increase was the most pronounced, with 0.043, 0.062, 0.057 and 0.048 L·cm in plots A–D, respectively. Also, droplet deposition uniformity in the leaf blade angle range 60°–90° was better after prewetting. These results should provide a valuable reference for future research and practice to improve the effectiveness of pesticides applied to cotton by aerial applications.

关键词： aerial spray cotton deposition flowering period leaf angle prewetting UAV

HTML PDF 收藏

NITROGEN USE AND MANAGEMENT IN ORCHARDS AND VEGETABLE FIELDS IN CHINA: CHALLENGES AND SOLUTIONS

《农业科学与工程前沿（英文）》 2022年第9卷第3期页码 386-395 doi: 10.15302/J-FASE-2022443

摘要：

● Excessive application of N fertilizers in orchards and vegetable fields (OVFs) in China is particularly common.

关键词： nitrogen fate nitrogen fertilizer orchards vegetable fields

HTML PDF 收藏

Extracts from cotton over the whole growing season induce

Ming LANG, Rui YU, Yongqing MA, Wei ZHANG, Christopher S. P. McErlean

《农业科学与工程前沿（英文）》 2017年第4卷第2期页码 228-236 doi: 10.15302/J-FASE-2017150

摘要： Five cotton cultivars and their parents were tested for induction of germination of Wallr. (sunflower broomrape) seeds in pot and field experiments. Germination rates induced by cotton root extracts were the highest followed by stem extracts then leaf extracts. Cotton seedlings at the six-leaf stage induced higher germination than seedling at the two- and four-leaf stage, in all five cotton cultivars and their parents. In the field, the highest concentration of cotton root extracts gave the highest germination rate of , and the lowest concentration of cotton root extracts gave the lowest germination rate. Methanol extracts of cotton rhizosphere soil gave the highest germination of . In general, the root, stem and leaf extracts were more active at the six-leaf stage than other seedling stages. In conclusion, extracts of cotton rhizosphere soil and tissues have high activity in the seedling stage. Extracts of cotton across the whole growing season were able to induce germination but displayed significant cultivar interactions.

关键词： agricultural systems cotton crop ecology crop rotation systems weed management

HTML PDF 收藏

棉花生产规模化、机械化、信息化、智能化和社会服务化发展战略研究

喻树迅,张雷,冯文娟

《中国工程科学》 2016年第18卷第1期页码 137-148 doi: 10.15302/J-SSCAE-2016.01.016

摘要：

棉花生产规模化、机械化、信息化、智能化和社会服务化发展是解决棉花生产过程中劳动力短缺、降低棉花生产成本、实现棉花产业现代化、巩固棉花产业优势地位的必然选择。为此，本文介绍了我国植棉的基本情况、棉花生产规模化、机械化、信息化、智能化和社会服务化的发展现状及制约因素，最后为加快实现快乐植棉提出了对策建议。

关键词：棉花现代化建议

HTML PDF 收藏

Advanced biomass materials: progress in the applications for energy, environmental, and emerging fields

《化学科学与工程前沿（英文）》 2023年第17卷第7期页码 795-797 doi: 10.1007/s11705-023-2336-6

摘要： Advanced biomass materials: progress in the applications for energy, environmental, and emerging fields

关键词： progress applications energy fields

HTML PDF 收藏

Engineering Fronts in fields of Energy and Electrical Science and Technologies in the report of

《能源前沿（英文）》 2023年第17卷第1期页码 5-8 doi: 10.1007/s11708-023-0868-6

摘要： . {{custom_ra.content}} . . . {{article.highlightEn}} . . . {{article.abstractEn}} . . . {{article.authorSummayEn}} .

HTML PDF 收藏

The perturbed magnetic fields caused by mechanical stress

QIN Fei, YAN Dong-mei

《机械工程前沿（英文）》 2006年第1卷第2期页码 151-156 doi: 10.1007/s11465-006-0015-1

摘要： In the framework of the linearized magnetoelastic theory, the perturbed magnetic fields caused by mechanical stress and deformation were investigated theoretically. Governing equations and boundary conditions to determine the perturbed fields were derived. The effect of mechanical deformation on the magnetic fields was taken into account by coupling structural displacement into the perturbed magnetic field continuous conditions on the boundary of the structure. As an example, the perturbed field of a half-plane magnetized structure caused by a point force was calculated by the Fourier transform method. The results show that the calculated magnetic intensity component normal to the boundary of the structure reaches its maximum at the point force acted while the component tangent to the boundary inverses its direction sharply. The magnetic induction of the perturbed field is proportional to the applied force. Magnitude analysis proved that since the applied magnetic field has a relative weak intensity such as the Earth s magnetic field, influence of the magnetic field on deformation of the structure can be neglected.

HTML PDF 收藏

Stem cell niches and endogenous electric fields in tissue repair

null

《医学前沿（英文）》 2011年第5卷第1期页码 40-44 doi: 10.1007/s11684-011-0108-z

摘要：

Adult stem cells are responsible for homeostasis and repair of many tissues. Endogenous adult stem cells reside in certain regions of organs, known as the stem cell niche, which is recognized to have an important role in regulating tissue maintenance and repair. In wound healing and tissue repair, stem cells are mobilized and recruited to the site of wound, and participate in the repair process. Many regulatory factors are involved in the stem cell-based repair process, including stem cell niches and endogenous wound electric fields, which are present at wound tissues and proved to be important in guiding wound healing. Here we briefly review the role of stem cell niches and endogenous electric fields in tissue repair, and hypothesize that endogenous electric fields become part of stem cell niche in the wound site.

关键词： stem cell stem cell niche electric field tissue repair

HTML PDF 收藏

Characterization of random stress fields obtained from polycrystalline aggregate calculations using multi-scale

Bruno SUDRET,Hung Xuan DANG,Marc BERVEILLER,Asmahana ZEGHADI,Thierry YALAMAS

《结构与土木工程前沿（英文）》 2015年第9卷第2期页码 121-140 doi: 10.1007/s11709-015-0290-1

摘要： The spatial variability of stress fields resulting from polycrystalline aggregate calculations involving random grain geometry and crystal orientations is investigated. A periodogram-based method is proposed to identify the properties of homogeneous Gaussian random fields (power spectral density and related covariance structure). Based on a set of finite element polycrystalline aggregate calculations the properties of the maximal principal stress field are identified. Two cases are considered, using either a fixed or random grain geometry. The stability of the method w.r.t the number of samples and the load level (up to 3.5% macroscopic deformation) is investigated.

关键词： polycrystalline aggregates crystal plasticity random fields spatial variability correlation structure

HTML PDF 收藏

Extrapolation reconstruction of wind pressure fields on the claddings of high-rise buildings

Yehua SUN, Guquan SONG, Hui LV

《结构与土木工程前沿（英文）》 2019年第13卷第3期页码 653-666 doi: 10.1007/s11709-018-0503-5

摘要： Recent research about reconstruction methods mainly used the interpolation reconstruction of the fluctuating wind pressure field on the surface. However, to investigate wind pressure at the edge of the building, the work presented in this paper focuses on the extrapolation reconstruction of wind pressure fields. Here, we propose an improved proper orthogonal decomposition (POD) and Kriging method with a von Kármán correlation function to resolve this issue. The studies show that it works well for not only interpolation reconstruction but also extrapolation reconstruction. The proposed method does require determination of the Hurst exponent and other parameters analysed from the original data. Hence, the fluctuating wind fields have been characterized by the von Kármán correlation function, as an a priori function. Compared with the cubic spline method and different variogram, preliminary results suggest less time consumption and high efficiency in extrapolation reconstruction at the edge.

关键词： extrapolation reconstruction proper orthogonal decomposition Kriging method von Kármán function Hurst exponent rescaled range analysis