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Approaches to achieve high grain yield and high resource use efficiency in rice

Jianchang YANG

《农业科学与工程前沿（英文）》 2015年 第2卷 第2期   页码 115-123 doi: 10.15302/J-FASE-2015055

摘要： This article discusses approaches to simultaneously increase grain yield and resource use efficiency in rice. Breeding nitrogen efficient cultivars without sacrificing rice yield potential, improving grain fill in later-flowering inferior spikelets and enhancing harvest index are three important approaches to achieving the dual goal of high grain yield and high resource use efficiency. Deeper root distribution and higher leaf photosynthetic N use efficiency at lower N rates could be used as selection criteria to develop N-efficient cultivars. Enhancing sink activity through increasing sugar-spikelet ratio at the heading time and enhancing the conversion efficiency from sucrose to starch though increasing the ratio of abscisic acid to ethylene in grains during grain fill could effectively improve grain fill in inferior spikelets. Several practices, such as post-anthesis controlled soil drying, an alternate wetting and moderate soil drying regime during the whole growing season, and non-flooded straw mulching cultivation, could substantially increase grain yield and water use efficiency, mainly via enhanced remobilization of stored carbon from vegetative tissues to grains and improved harvest index. Further research is needed to understand synergistic interaction between water and N on crop and soil and the mechanism underlying high resource use efficiency in high-yielding rice.

关键词： rice     nitrogen-efficient cultivar     grain fill     harvest index     nitrogen use efficiency     water use efficiency    

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Genetic study and molecular breeding for high phosphorus use efficiency in maize

null

《农业科学与工程前沿（英文）》 2019年 第6卷 第4期   页码 366-379 doi: 10.15302/J-FASE-2019278

摘要：

Phosphorus is the second most important macronutrient after nitrogen and it has many vital functions in the life of plants. Most soils have a low available P content, which has become a key limiting factor for increasing crop production. Also, low P use efficiency (PUE) of crops in conjunction with excessive application of P fertilizers has resulted in serious environmental problems. Thus, dissecting the genetic architecture of crop PUE, mining related quantitative trait loci (QTL) and using molecular breeding methods to improve high PUE germplasm are of great significance and serve as an efficient approach for the development of sustainable agriculture. In this review, molecular and phenotypic characteristics of maize inbred lines with high PUE, related QTL and genes as well as low-P responses are summarized. Based on this, a breeding strategy applying genomic selection as the core, and integrating the existing genetic information and molecular breeding techniques is proposed for breeding high PUE maize inbred lines and hybrids.

关键词： maize     phosphorus use efficiency     quantitative trait loci     genetic study     molecular breeding     genomic selection    

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Special issue: Technologies for future high-efficiency industrial silicon wafer solar cells

《能源前沿（英文）》 2017年 第11卷 第1期   页码 1-3 doi: 10.1007/s11708-016-0436-4

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Experimental study on high-efficiency polishing for potassium dihydrogen phosphate (KDP) crystal by using

Ziyuan LIU, Hang GAO, Dongming GUO

《机械工程前沿（英文）》 2020年 第15卷 第2期   页码 294-302 doi: 10.1007/s11465-019-0576-4

摘要： A high-efficiency polishing approach using two-phase air–water fluid (TAWF) is proposed to avoid surface contamination and solve the inefficiency of previous water-dissolution polishing techniques for potassium dihydrogen phosphate (KDP) crystal. In the proposed method, controllable deliquescence is implemented without any chemical impurity. The product of deliquescence is then removed by a polishing pad to achieve surface planarization. The mechanism underlying TAWF polishing is analyzed, a special device is built to polish the KDP crystal, and the effect of relative humidity (RH) on polishing performance is studied. The relationship between key parameters of polishing and surface planarization is also investigated. Results show that the polishing performance is improved with increasing RH. However, precisely controlling the RH is extremely difficult during TAWF polishing. Controllable deliquescence can easily be disrupted once the RH fluctuates, which therefore needs to be restricted to a low level to avoid its influence on deliquescence rate. The material removal of TAWF polishing is mainly attributed to the synergistic effect of deliquescence and the polishing pad. Excessive polishing pressure and revolution rate remarkably reduce the life of the polishing pad and the surface quality of the KDP crystal. TAWF polishing using IC-1000 and TEC-168S increase the machining efficiency by 150%, and a smooth surface with a root mean square surface roughness of 5.5 nm is obtained.

关键词： potassium dihydrogen phosphate (KDP) crystal     controllable deliquescence     two-phase air–water fluid     high-efficiency polishing     material removal    

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A thermoelectric generator and water-cooling assisted high conversion efficiency polycrystalline silicon

Zekun LIU, Shuang YUAN, Yi YUAN, Guojian LI, Qiang WANG

《能源前沿（英文）》 2021年 第15卷 第2期   页码 358-366 doi: 10.1007/s11708-020-0712-1

摘要： Solar energy has been increasing its share in the global energy structure. However, the thermal radiation brought by sunlight will attenuate the efficiency of solar cells. To reduce the temperature of the photovoltaic (PV) cell and improve the utilization efficiency of solar energy, a hybrid system composed of the PV cell, a thermoelectric generator (TEG), and a water-cooled plate (WCP) was manufactured. The WCP cannot only cool the PV cell, but also effectively generate additional electric energy with the TEG using the waste heat of the PV cell. The changes in the efficiency and power density of the hybrid system were obtained by real time monitoring. The thermal and electrical tests were performed at different irradiations and the same experiment temperature of 22°C. At a light intensity of 1000 W/m , the steady-state temperature of the PV cell decreases from 86.8°C to 54.1°C, and the overall efficiency increases from 15.6% to 21.1%. At a light intensity of 800 W/m , the steady-state temperature of the PV cell decreases from 70°C to 45.8°C, and the overall efficiency increases from 9.28% to 12.59%. At a light intensity of 400 W/m , the steady-state temperature of the PV cell decreases from 38.5°C to 31.5°C, and the overall efficiency is approximately 3.8%, basically remain unchanged.

关键词： photovoltaic (PV)     thermoelectric generator     conversion efficiency     hybrid energy systems     water-cooled plate (WCP)    

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高效加工技术及其应用研究

艾兴

《中国工程科学》 2000年 第2卷 第11期   页码 40-51

摘要：

在机械加工领域，切削加工是应用最广泛的一种加工方法，其发展方向主要是研究髙速切削，对超硬材料加工，主要是发展磨削、超声和放电等高效复合加工技术。文章介绍对髙效切削加工和高效复合加工技术的理论研究和技术开发与应用及所取得的重要成果，主要包括高速切削基础理论、陶瓷刀具材料研究新体系和超硬材料断续磨、超声和电火花的复合加工理论与技术的研究开发。生产实际应用结果表明，高效加工技术可以大幅度提髙加工效率，改善加工表面质量，降低加工成本。

关键词： 高效加工技术     髙速切削     陶瓷刀具材料     断续磨-间瞭脉冲放电复合加工     超声-间隙脉冲放电复合加工    

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Divergent Changes in Vegetation Greenness, Productivity, and Rainfall Use Efficiency Are Characteristicof Ecological Restoration Towards High-Quality Development in the Yellow River Basin, China

Yang Yu,Ting Hua,Liding Chen,Zhiqiang Zhang,Paulo Pereira,

《工程（英文）》 doi: 10.1016/j.eng.2023.07.012

摘要： Globally, vegetation has been changing dramatically. The vegetation–water dynamic is key to understanding ecosystem structure and functioning in water-limited ecosystems. Continual satellite monitoring has detected global vegetation greening. However, a greenness increase does not mean that ecosystem functions increase. The intricate interplays resulting from the relationships between vegetation and precipitation must be more adequately comprehended. In this study, satellite data, for example, leaf area index (LAI), net primary production (NPP) and rainfall use efficiency (RUE), were used to quantify vegetation dynamics and their relationship with rainfall in different reaches of the Yellow River Basin (YRB). A sequential regression method was used to detect trends of NPP sensitivity to rainfall. The results showed that 34.53% of the YRB exhibited a significant greening trend since 2000. Among them, 20.54%, 53.37%, and 16.73% of upper, middle, and lower reach areas showed a significant positive trend, respectively. NPP showed a similar trend to LAI in the YRB upper, middle, and lower reaches. A notable difference was noted in the distributions and trends of RUE across the upper, middle, and lower reaches. Moreover, there were significant trends in vegetation–rainfall sensitivity in 16.86% of the YRB’s middle reaches—14.08% showed negative trends and 2.78% positive trends. A total of 8.41% of the YRB exhibited a marked increase in LAI, NPP, and RUE. Subsequently, strategic locations reliant on the correlation between vegetation and rainfall were identified and designated for restoration planning purposes to propose future ecological restoration efforts. Our analysis indicates that the middle reach of the YRB exhibited the most significant variation in vegetation greenness and productivity. The present study underscores the significance of examining the correlation between vegetation and rainfall within the context of the high-quality development strategy of the YRB. The outcomes of our analysis and the proposed ecological restoration framework can provide decision-makers with valuable insights for executing rational basin pattern optimization and sustainable management.

关键词： Vegetation greenness     Vegetation productivity     Rainfall use efficiency     Sensitivity     Yellow River Basin    

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基于双正交复序列的高效扩频调制方法

史小红

《中国工程科学》 2012年 第14卷 第3期   页码 108-112

摘要：

提出了一种采用双正交复序列的高效扩频调制与解调方法（DoCS）。输入数据比特流被分割为长度为M的组，每组的M比特作为输入码字，从2M-2个长度为L的DoCS序列中选择一条序列进行发送，被选中的序列以QPSK方式调制在载波上，实现扩频通信。文中还提出了一种前向相位校正(FPC)方法来解决该系统中收发两端的载波同步问题。

关键词： 调制与解调技术     高效扩频调制     前向相位校正     双正交码    

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High-efficiency inspecting method for mobile robots based on task planning for heat transfer tubes in

《机械工程前沿（英文）》 2023年 第18卷 第2期 doi: 10.1007/s11465-022-0741-z

摘要： Many heat transfer tubes are distributed on the tube plates of a steam generator that requires periodic inspection by robots. Existing inspection robots are usually involved in issues: Robots with manipulators need complicated installation due to their fixed base; tube mobile robots suffer from low running efficiency because of their structural restricts. Since there are thousands of tubes to be checked, task planning is essential to guarantee the precise, orderly, and efficient inspection process. Most in-service robots check the task tubes using row-by-row and column-by-column planning. This leads to unnecessary inspections, resulting in a long shutdown and affecting the regular operation of a nuclear power plant. Therefore, this paper introduces the structure and control system of a dexterous robot and proposes a task planning method. This method proceeds into three steps: task allocation, base position search, and sequence planning. To allocate the task regions, this method calculates the tool work matrix and proposes a criterion to evaluate a sub-region. And then all tasks contained in the sub-region are considered globally to search the base positions. Lastly, we apply an improved ant colony algorithm for base sequence planning and determine the inspection orders according to the planned path. We validated the optimized algorithm by conducting task planning experiments using our robot on a tube sheet. The results show that the proposed method can accomplish full task coverage with few repetitive or redundant inspections and it increases the efficiency by 33.31% compared to the traditional planning algorithms.

关键词： steam generator transfer tubes     mobile robot     dexterous structure     task planning     efficient inspection    

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Digital high-efficiency print forming method and device for multi-material casting molds

Zhongde SHAN, Zhi GUO, Dong DU, Feng LIU, Wenjiang LI

《机械工程前沿（英文）》 2020年 第15卷 第2期   页码 328-337 doi: 10.1007/s11465-019-0574-6

摘要： Sand mold 3D printing technology based on the principle of droplet ejection has undergone rapid development in recent years and has elicited increasing attention from engineers and technicians. However, current sand mold 3D printing technology exhibits several problems, such as single-material printing molds, low manufacturing efficiency, and necessary post-process drying and heating for the manufacture of sand molds. This study proposes a novel high-efficiency print forming method and device for multi-material casting molds. The proposed method is specifically related to the integrated forming of two-way coating and printing and the short-flow manufacture of roller compaction and layered heating. These processes can realize the high-efficiency print forming of high-performance sand molds. Experimental results demonstrate that the efficiency of sand mold fabrication can be increased by 200% using the proposed two-way coating and printing method. The integrated forming method for layered heating and roller compaction presented in this study effectively shortens the manufacturing process for 3D-printed sand molds, increases sand mold strength by 63.8%, and reduces resin usage by approximately 30%. The manufacture of multi-material casting molds is demonstrated on typical wheeled cast-iron parts. This research provides theoretical guidance for the engineering application of sand mold 3D printing.

关键词： multi-material casting mold     3D printing     efficient print forming method    

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Research on overlaying welding rod of high hardness maraging steel

PAN Yong-ming, CHEN Shao-wei

《机械工程前沿（英文）》 2006年 第1卷 第4期   页码 465-467 doi: 10.1007/s11465-006-0060-9

摘要： The development of new maraging steel overlaying welding rod, which contains Co, Mo, W and V alloy, solved the problems of poor homogeneity of hardness and mechanical process, prolonged the service life of wear-resistant components and increased the productive efficiency of repairing, greatly benefiting the national economy.

关键词： development     productive efficiency     national     homogeneity     mechanical    

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High-quality industrial n-type silicon wafers with an efficiency of over 23% for Si heterojunction solar

Fanying MENG,Jinning LIU,Leilei SHEN,Jianhua SHI,Anjun HAN,Liping ZHANG,Yucheng LIU,Jian YU,Junkai ZHANG,Rui ZHOU,Zhengxin LIU

《能源前沿（英文）》 2017年 第11卷 第1期   页码 78-84 doi: 10.1007/s11708-016-0435-5

摘要： n-type CZ-Si wafers featuring longer minority carrier lifetime and higher tolerance of certain metal contamination can offer one of the best Si-based solar cells. In this study, Si heterojuction (SHJ) solar cells which was fabricated with different wafers in the top, middle and tail positions of the ingot, exhibited a stable high efficiency of>22% in spite of the various profiles of the resistivity and lifetime, which demonstrated the high material utilization of n-type ingot. In addition, for effectively converting the sunlight into electrical power, the pyramid size, pyramid density and roughness of surface of the Cz-Si wafer were investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM). Furthermore, the dependence of SHJ solar cell open-circuit voltage on the surface topography was discussed, which indicated that the uniformity of surface pyramid helps to improve the open-circuit voltage and conversion efficiency. Moreover, the simulation revealed that the highest efficiency of the SHJ solar cell could be achieved by the wafer with a thickness of 100 µm. Fortunately, over 23% of the conversion efficiency of the SHJ solar cell with a wafer thickness of 100 µm was obtained based on the systematic optimization of cell fabrication process in the pilot production line. Evidently, the large availability of both n-type ingot and thinner wafer strongly supported the lower cost fabrication of high efficiency SHJ solar cell.

关键词： n-type Cz-Si     thinner wafer     surface texture     high efficiency     SHJ solar cell    

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Microwave-induced high-energy sites and targeted energy transition promising for efficient energy deployment

《能源前沿（英文）》 2022年 第16卷 第6期   页码 931-942 doi: 10.1007/s11708-021-0771-y

摘要： Diverse interactions between microwaves and irradiated media provide a solid foundation for identifying novel organization pathways for energy flow. In this study, a high-energy-site phenomenon and targeted-energy transition mechanism were identified in a particular microwave heating (MH) process. Intense discharges were observed when microwaves were imposed on irregularly sized SiC particles, producing tremendous heat that was 8-fold the amount generated in the discharge-free case. Energy efficiency was thereby greatly improved in the electricity-microwaves-effective heat transition. Meanwhile, the dispersed microwave field energy concentrated in small sites, where local temperatures could reach 2000°C– 4000°C, with the energy density reaching up to 4.0 × 105 W/kg. This can be called a high-energy site phenomenon which could induce further processes or reactions enhancement by coupling effects of heat, light, and plasma. The whole process, including microwave energy concentration and intense site-energy release, shapes a targeted-energy transition mechanism that can be optimized in a controlled manner through morphology design. In particular, the discharge intensity, frequency, and high-energy sites were strengthened through the fabrication of sharp nano/microstructures, conferring twice the energy efficiency of untreated metal wires. The microwave-induced high-energy sites and targeted energy transition provide an important pathway for high-efficiency energy deployment and may lead to promising applications.

关键词： microwave discharge     high-energy sites     targeted-energy transition     morphology design     energy efficiency    

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Performance assessment of Alccofine with silica fume, fly ash and slag for development of high strength

Shivang D. JAYSWAL; Mahesh MUNGULE

《结构与土木工程前沿（英文）》 2022年 第16卷 第5期   页码 576-588 doi: 10.1007/s11709-022-0826-0

摘要： Previous studies on concrete have identified silica fume (SF) as the most effective supplementary material, whereas fly ash (FA) and slag have been identified as economical materials with long term strength potential. Development of blended cement mortar referred to as blended mortar (BM) requires similar assessment. The present study explores the application of Alccofine (AL) as supplementary material and compares its performance with conventional materials namely SF, FA and ground granulated blast furnace slag (GGBS). The mortar specimens with binder to fine-aggregates (b/f ) ratio of 1:2 are prepared at water to binder (w/b) ratios of 0.4 and 0.35. The strength values and stress-strain curve for control and BM specimens are obtained at 7, 28, 56, and 90 d curing periods. The assessment based on strength activity index, k-value method and strength estimation model confirms that AL, despite lower pozzolanic activity, contributes to strength gain, due to reduced dilution effect. Assessment of stress-strain curves suggests that the effect of w/b ratio is more dominant on the elastic modulus of BM specimens than on control specimens. The observations from the study identify enhanced strength gain, improved elastic modulus and higher energy absorption as key contributions of AL making it a potential supplementary material.

关键词： Alccofine     high strength mortar     efficiency factor     dilution effect    

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A methodology for regulating fuel stratification and improving fuel economy of GCI mode via double main-injection strategy

《能源前沿（英文）》 2023年 第17卷 第5期   页码 678-691 doi: 10.1007/s11708-022-0859-z

摘要： Gasoline compression ignition (GCI) combustion faces problems such as high maximum pressure rise rate (MPRR) and combustion deterioration at high loads. This paper aims to improve the engine performance of the GCI mode by regulating concentration stratification and promoting fuel-gas mixing by utilizing the double main-injection (DMI) strategy. Two direct injectors simultaneously injected gasoline with an octane number of 82.7 to investigate the energy ratio between the two main-injection and exhaust gas recirculation (EGR) on combustion and emissions. High-load experiments were conducted using the DMI strategy and compared with the single main-injection (SMI) strategy and conventional diesel combustion. The results indicate that the DMI strategy have a great potential to reduce the MPRR and improve the fuel economy of the GCI mode. At a 10 bar indicated mean effective pressure, increasing the main-injection-2 ratio (Rm-2) shortens the injection duration and increases the mean mixing time. Optimized Rm-2 could moderate the trade-off between the MPRR and the indicated specific fuel consumption with both reductions. An appropriate EGR should be adopted considering combustion and emissions. The DMI strategy achieves a highly efficient and stable combustion at high loads, with an indicated thermal efficiency (ITE) greater than 48%, CO and THC emissions at low levels, and MPRR within a reasonable range. Compared with the SMI strategy, the maximum improvement of the ITE is 1.5%, and the maximum reduction of MPRR is 1.5 bar/°CA.

关键词： gasoline compression ignition     injection strategy     fuel stratification     high efficiency     high load    

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标题 作者 时间 类型 操作

Approaches to achieve high grain yield and high resource use efficiency in rice

Jianchang YANG

期刊论文

Genetic study and molecular breeding for high phosphorus use efficiency in maize

null

期刊论文

Special issue: Technologies for future high-efficiency industrial silicon wafer solar cells

期刊论文

Experimental study on high-efficiency polishing for potassium dihydrogen phosphate (KDP) crystal by using

Ziyuan LIU, Hang GAO, Dongming GUO

期刊论文

A thermoelectric generator and water-cooling assisted high conversion efficiency polycrystalline silicon

Zekun LIU, Shuang YUAN, Yi YUAN, Guojian LI, Qiang WANG

期刊论文

高效加工技术及其应用研究

艾兴

期刊论文

Divergent Changes in Vegetation Greenness, Productivity, and Rainfall Use Efficiency Are Characteristicof Ecological Restoration Towards High-Quality Development in the Yellow River Basin, China

Yang Yu,Ting Hua,Liding Chen,Zhiqiang Zhang,Paulo Pereira,

期刊论文

基于双正交复序列的高效扩频调制方法

史小红

期刊论文

High-efficiency inspecting method for mobile robots based on task planning for heat transfer tubes in

期刊论文

Digital high-efficiency print forming method and device for multi-material casting molds

Zhongde SHAN, Zhi GUO, Dong DU, Feng LIU, Wenjiang LI

期刊论文

Research on overlaying welding rod of high hardness maraging steel

PAN Yong-ming, CHEN Shao-wei

期刊论文

High-quality industrial n-type silicon wafers with an efficiency of over 23% for Si heterojunction solar

Fanying MENG,Jinning LIU,Leilei SHEN,Jianhua SHI,Anjun HAN,Liping ZHANG,Yucheng LIU,Jian YU,Junkai ZHANG,Rui ZHOU,Zhengxin LIU

期刊论文

Microwave-induced high-energy sites and targeted energy transition promising for efficient energy deployment

期刊论文

Performance assessment of Alccofine with silica fume, fly ash and slag for development of high strength

Shivang D. JAYSWAL; Mahesh MUNGULE

期刊论文

A methodology for regulating fuel stratification and improving fuel economy of GCI mode via double main-injection strategy

期刊论文