Innovation and development of the third-generation hybrid rice technology

The breeding and large-scale application of hybrid rice contribute significantly to the food supply worldwide.Currently,hybrid seed production uses cytoplasmic male sterile(CMS)lines or photoperiod/thermo-sensitive genic male sterile(PTGMS)lines as female parent.Despite huge successes,both systems have intrinsic problems.CMS systems are mainly restricted by the narrow restorer resources that make it difficult to breed superior hybrids,while PTGMS systems are limited by conditional sterility of the male sterile lines that makes the propagation of both PTGMS seeds and hybrid seeds vulnerable to unpredictable climate changes.Recessive nuclear male sterile(NMS)lines insensitive to environmental conditions are widely distributed and are ideal for hybrid rice breeding and production,but the lack of effective ways to propagate the pure NMS lines in a large scale renders it impossible to use them for hybrid rice production.The development of"the third-generation hybrid rice technology"enables efficient propagation of the pure NMS lines in commercial scale.This paper discusses the establishment of"the thirdgeneration hybrid rice technology"and further innovations.This new technology breaks the limitations of CMS and PTGMS systems and will bring a big leap forward in hybrid rice production.

Embryo quality and chromosomal abnormality in embryos from couples undergoing assisted reproductive technology using preimplantation genetic screening

Objective:To detect common chromosomal aneuploidy variations in embryos from couples undergoing assisted reproductive technology and preimplantation genetic screening and their possible associations with embryo quality.Methods:In this study,359 embryos from 62 couples were screened for chromosomes 13,21,18,X,and Y by fluorescence insitu hybridization.For biopsy of blastomere,a laser was used to remove a significantly smaller portion of the zona pellucida.One blastomere was gently biopsied by an aspiration pipette through the hole.After biopsy,the embryo was immediately returned to the embryo scope until transfer.Embryo integrity and blastocyst formation were assessed on day 5.Results:Totally,282 embryos from 62 couples were evaluated.The chromosomes were normal in 199(70.57%)embryos and abnormal in 83(29.43%)embryos.There was no significant association between the quality of embryos and numerical chromosomal abnormality(P=0.67).Conclusions:Embryo quality is not significantly correlated with its genetic status.Hence,the quality of embryos determined by morphological parameters is not an appropriate method for choosing embryos without these abnormalities.

The 8×10 GHz Receiver Optical Subassembly Based on Silica Hybrid Integration Technology for Data Center Interconnection

An 8×10 GHz receiver optical sub-assembly （ROSA） consisting of an 8-channel arrayed waveguide grating （AWG） and an 8-channel PIN photodetector （PD） array is designed and fabricated based on silica hybrid integration technology. Multimode output waveguides in the silica AWG with 2% refractive index difference are used to obtain fiat-top spectra. The output waveguide facet is polished to 45° bevel to change the light propagation direction into the mesa-type PIN PD, which simplifies the packaging process. The experimentM results show that the single channel I dB bandwidth of AWG ranges from 2.12nm to 3.06nm, the ROSA responsivity ranges from 0.097 A/W to 0.158A/W, and the 3dB bandwidth is up to 11 GHz. It is promising to be applied in the eight-lane WDM transmission system in data center interconnection.

A Single Mode Hybrid Ⅲ-Ⅴ/Silicon On-Chip Laser Based on Flip-Chip Bonding Technology for Optical Interconnection

A single mode hybrid Ⅲ-Ⅴ/silicon on-chip laser based on the flip-chip bonding technology for on-chip optical interconnection is demonstrated. A single mode Fabry-Perot laser structure with micro-structures on an InP ridge waveguide is designed and fabricated on an InP/AIGaInAs multiple quantum well epitaxial layer structure wafer by using i-line lithography. Then, a silicon waveguide platform including a laser mounting stage is designed and fabricated on a silicon-on-insulator substrate. The single mode laser is flip-chip bonded on the laser mounting stage. The lasing light is butt-coupling to the silicon waveguide. The laser power output from a silicon waveguide is 1.3roW, and the threshold is 37mA at room temperature and continuous wave operation.

Hybrid Laser Technology for Creation of Doped Biomedical Layers

Hybrid laser technologies for deposition of thin films and basic schemes of combination of pulsed laser deposition (PLD) with magnetron sputtering and RF discharges or two lasers or three laser deposition systems are presented. Experiences with deposition of chromium doped diamond-like carbon (DLC) films for coating of prostheses are described. Layers of different chromium concentrations were prepared using hybrid systems (PLD + magnetron sputtering or by double PLD). Results of physical and mechanical characterization of film properties and biomedical tests of trivalent and toxic hexavalent chromium are given. Experiences with double laser deposition of DLC layers doped with silver are also mentioned.

Hybrid location determination technology within urban and indoor environment based on Cell-ID and path loss

The location determination technology based on simple delay evaluations or GPS is not accurate enough or even impossible in urban and indoor environments due to the multi path propagation.To enhance the location accuracy and reduce the operation cost within these environments, this paper proposes a novel hybrid location determination technology which combines CELL ID with the database correlation method. The proposed method generate the prediction database of path loss according to CELL ID, and after the computation the smallest squared error of measured path loss and the prediction path loss, the location of the mobile terminal is decided by the coordinates of the best matching matrix entry.

Omics Technologies Reveal Abundant Natural Variation in Metabolites and Transcripts among Conventional Maize Hybrids

In this report we have evaluated metabolite and RNA profiling technologies to begin to understand the natural variation in these biomolecules found in commercial-quality, conventional (non-GM) maize hybrids. Our analyses focus on mature grain, the article of commerce that is most typically subjected to the rigorous studies involved in the comparative safety assessment of GM products. We have used a population of conventionally-bred maize hybrids that derive from closely related inbred parents grown under standard field conditions across geographically similar locations. This study highlights the large amount of natural variation in metabolites and transcripts across conventional maize germplasm grown under normal field conditions, and underscores the critical need for further extensive studies before these technologies can be seriously considered for utility in the comparative safety assessment of GM crops.

激光复合冷喷涂技术研究进展

冷喷涂是一种基于材料高速撞击产生剧烈塑性变形实现结合的沉积方法,具备加工温度低、沉积效率高、热影响小等优势,已在增材制造、工业关键零部件的修复再制造等领域展现出巨大潜力。冷喷涂复合制造技术是一种新兴技术,其中激光复合冷喷涂是一个重要的方向,近年来得到了越来越多的关注。对激光复合冷喷涂技术研究进展进行回顾和总结,对激光预处理、激光同步复合和激光后处理3种复合方式进行重点阐释。针对每种复合方式,分别从复合原理、复合优势及复合效果3个方面进行总结,对比激光复合冷喷涂技术与单一技术在沉积层微观组织以及性能等方面的差异。通过对激光复合冷喷涂技术最新进展的全面总结和归纳,将为进一步推动激光复合冷喷涂技术的研究和应用提供指导和参考。

苦荞开花习性及其有性杂交技术研究

为探究苦荞开花习性及其有性杂交技术,本研究以品苦1号、米荞和HPE7为试验材料,通过观察苦荞开花习性和花器结构,采用刚开花人工去雄法进行杂交组合配置。结果表明,品苦1号、米荞和HPE7开花授粉的花朵数量存在较大差异,花朵的大小也存在微小的差异;人工杂交时选择刚开放的内外两轮花药粉红色、表面光滑没有授粉的花朵完成去雄工作;品苦1号和米荞为亲本的杂交组合,正交或反交结实率均达36%以上,表现出较高的亲和力;HPE7为父本的杂交组合,杂交种结实率均达35%以上,HPE7为母本的杂交组合,杂交种结实率为0,HPE7不适合作为母本使用。

基于“技术道德化”理论的生成式人工智能教育应用潜能与风险研究

随着生成式人工智能的快速发展及其在教育领域的广泛应用,国内外研究者围绕它及其背后的大语言模型教育应用问题展开了热烈的讨论,但大部分研究因缺乏对生成式人工智能技术原理的了解而在问题探讨中存在伊莉莎效应。研究首先在对生成式人工智能技术学原理进行深入剖析的基础上,从维贝克“人—技杂合”视角对生成式人工智能的本质展开技术哲学分析;其次,基于“技术道德化”理论分析了生成式人工智能教育应用的四大潜能和面临的五大风险挑战;最后,提出基于“人—技杂合”的思想从“设计者”和“使用者”两种视角构建“双向奔赴”的全球人工智能治理体系,将成为未来探索的重要方向。

燃料电池船舶混合动力系统能量管理研究综述

在“双碳”目标下,发展燃料电池船舶是实现航运业转型升级和低碳化的重要发展方向之一。面对当前燃料电池上船的诸多问题,混合动力系统成为燃料电池船舶应用的有效解决方案,其能量管理的研究也成为核心研究方向之一。系统梳理燃料电池船舶的发展概况,针对燃料电池船舶多类型能源能量管理中涉及的能量调度问题以及变换器功率分配问题进行综述;分析各类方法的优缺点及其在实船上应用的可能性;探讨燃料电池船舶推广可行性和发展方向,以期能为技术创新和工程应用提供参考。

核型分析联合其他遗传学检测技术在高龄孕妇产前诊断中的应用

目的探讨核型分析联合单核苷酸多态性微阵列技术(single nucleotide polymorphism array,SNP array)或荧光原位杂交技术(fluorescence in situ hybridization,FISH)或细菌人工染色体微珠标记技术(BACs on Beads,BoBs)在高龄孕妇产前诊断中的应用价值。方法回顾性研究因高龄行产前诊断的930例孕妇,全部行核型分析,联合BoBs检测420例,联合SNP array检测343例,联合FISH检测167例,分析其染色体结果及妊娠结局。结果930例胎儿中,核型异常192例(20.7%),三体综合征中以21-三体居多,性染色体异常中以克氏征居多。在核型联合其他检测中,联合SNP array检测可显著提高胎儿染色体异常检出率,差异有统计学意义(χ^(2)=6.191,P=0.013)。对于染色体嵌合体的诊断,核型联合FISH检测可更精准地确定嵌合类型及比例。孤立性高龄胎儿染色体异常风险相对较低,高龄合并无创高危胎儿染色体异常率最高,在高龄合并超声软指标中,随超声软指标数目增多,染色体异常率随之升高(P=0.001)。高龄孕妇年龄与核型异常、非整倍体尤其21三体的发生率呈正相关(P<0.05)。结论孤立性高龄孕妇胎儿染色体异常风险相对较低,高龄合并无创高危胎儿染色体异常的风险高,随超声软指标数目增多、孕妇年龄增长胎儿染色体异常的风险增加,核型联合FISH检测可更精准地确定嵌合类型及比例,核型分析联合其他检测尤其与SNP array技术可显著提高染色体异常检出率,有利于遗传咨询及再生育指导,是高龄孕妇首选的产前诊断方案。

线上线下混合模式下问题导向式教学资源建设和应用——以“海洋技术导论”课程为例

以海洋技术专业本科课程“海洋技术导论”为例,详细阐述了线上线下混合教学模式下课程教学资源的建设和应用。以学生融会贯通能力欠缺、学习效率不高、能力训练手段缺乏三大痛点问题为导向,建设了线上和线下理论教学资源、线上虚拟平台、线下实践基地等线上线下融合式和虚拟实操孪生式教学资源。在教学资源应用上,突出以学生为中心和以教学目标为导向两个特点,结合课程的完整流程阐述了课程教学资源的总体使用方式。

基于动态模拟技术的混动车辆发动机电控单元检测系统设计

电控单元是混动车辆发动机中的重要组成部分,对于发动机以及混动车辆的行驶性能产生直接影响,为保证电控单元的运行正常,利用动态模拟技术,优化设计了混动车辆发动机电控单元检测系统;改装温度、转速等传感器设备以及信号处理器设备,调整系统电路的连接方式,实现硬件系统的优化;利用动态模拟技术模拟混动车辆发动机电控过程,结合不同故障类型下电控单元的运行特征,设置系统的检测标准;采集电控单元输出信号,从时域和频域两个方面提取信号特征,最终通过特征匹配确定电控单元状态、故障类型以及故障位置,实现系统的电控单元检测功能;综合混动车辆发动机的3种运行场景,通过系统测试实验得出结论:与传统检测系统相比,优化设计系统的漏检率和误检率分别降低了2.59%和2.05%,由此证明优化设计系统具有良好的检测功能。

军队院校工程类专业课混合式教学实现方法研究

针对军队院校工程类专业课实施混合式教学的实际困难,探讨了一套实现方法。分析了军队院校的教学特点,包括教学管理方式、教学平台、课程设置、教学内容和教学对象五个方面。然后,以机载雷达原理与系统课程为例,探讨了军队院校混合式教学的实现方法,包括线上线下教学内容划分、线上教学资源建设、线下教学资源建设、线上线下教学的组织与实施及学员考核与评价的方法。

混合动力汽车转向稳定性多传感器融合控制技术

为了满足汽车行驶稳定性要求,当前依托于单一传感信息进行转向控制,容易忽略很多影响因素,使得控制后汽车转向质心侧偏角依旧较大。因此,混合动力汽车提出转向稳定性多传感器融合控制技术。考虑混合动力汽车转向过程中的动态特性,构建转向动力学模型,并计算出车辆理想横摆角速度。深入分析横摆角速度、滑移率对车辆转向稳定性的影响,得出期望的横摆力矩和滑移率调整力矩。将汽车转向稳定性控制问题看作二次规划问题,结合BP神经网络和常规PID控制器,设计转向稳定性控制算法,利用车辆转向参数的理想值、实际值和偏差值推算出稳定性控制参数。结合融合多传感器实时采集信息,推算出汽车转向姿态误差代入控制结构中,给出优化后的控制参数。实验结果表明:新提出的控制技术应用后,车辆转向的质心侧偏角不超过±0.012 rad/s,满足了混合动力汽车转向行驶要求。

基于混合式教学模式的“信息技术”课程教学改革

如今,互联网技术在许多领域得到广泛应用,极大地改变了人们的学习和生活。作为一种新型的教学方式,混合式教学模式充分利用了互联网教学的便捷性,特别是将线上教学与线下教学有机结合,被认为是未来课程改革的关键。在信息技术高速发展的环境下,需要加强“信息技术”课程教学改革,采用混合式教学模式以提升教学效率,使得“信息技术”课程更为完善,更能够满足学生的学习需求。

“食品加工技术”线上线下混合式教学改革探索

在现代教育中,线上线下相结合的教学模式越来越普遍。针对“食品加工技术”实践性很强的课程,线上线下混合式教学模式是一种非常适合的教学方式。通过线上平台的灵活安排和数字化资源的丰富呈现,可提高教学效率和教学质量,同时通过线下实践活动,可强化学生的实践能力和团队合作精神。线上线下混合式教学模式是一种具有很大潜力的教学方式,通过不断的实践和改进,可更好地提高学生的学习效果和兴趣,同时也可为未来的教育教学模式提供更多借鉴和参考。

混合式教学模式下的信息技术课程教学改革——以北京工业职业技术学院为例

疫情的影响,高职院校面临停课、延期开学的困境,而互联网技术的发展、网络带宽的提升、移动设备的普及,以及师生对灵活学习时间和地点的更多要求,这一切加速了混合式教学的教学改革。以北京工业职业技术学院为例,分析了信息技术课程的教学现状,探讨了资源建设、教学要求、思政课堂、考核评价多个方面的教学改革措施,以及师生在教学改革当中取得的成效,以期为高职院校的信息技术课程改革提供参考。