Border effects of the main and ratoon crops in the rice ratooning system

The border effect(BE)is widely observed in crop field experiments,and it has been extensively studied in many crops.However,only limited attention has been paid to the BE of ratoon rice.We conducted field experiments on ratoon rice in Qichun County,Hubei Province,Central China in 2018 and 2019 to compare the BE in the main and ratoon crops,and to quantify the contribution of BE in the main crop to that in the ratoon crop.The BE of two hybrid varieties was measured for the outermost,second outermost,and third outermost rows in each plot of both crops.To determine the contribution of BE between the two crops,portions of hills in the outermost and second outermost rows were uprooted during the harvest of the main crop so that the second and third outermost rows then became the outermost rows in the ratoon crop.Overall,the BE on grain yield was greater in the main crop than in the ratoon crop.In the main crop,the BE on grain yield was 98.3%in the outermost row,which was explained by the BE on panicles m^(–2),spikelets/panicle,spikelets m^(–2),and total dry weight.In the ratoon crop,the BE on grain yield was reduced to 60.9 and 27.6%with and without the contribution of the BE in the main crop,respectively.Consequently,55.1%of the BE on grain yield in the ratoon crop was contributed from the main crop.High stubble dry weight and non-structural carbohydrate(NSC)accumulation at the harvest of the main crop were responsible for the contribution of BE in the main crop to that in the ratoon crop.Our results suggest that increases in stubble dry weight and NSC accumulation at the harvest of the main crop could be important strategies for developing high-yielding cropping practices in the rice ratooning system.

ADC border effect and suppression of quantization error in the digital dynamic measurement

The digital measurement and processing is an important direction in the measurement and control field. The quantization error widely existing in the digital processing is always the decisive factor that restricts the development and applications of the digital technology. In this paper, we find that the stability of the digital quantization system is obviously better than the quantization resolution. The application of a border effect in the digital quantization can greatly improve the accuracy of digital processing. Its effective precision has nothing to do with the number of quantization bits, which is only related to the stability of the quantization system. The high precision measurement results obtained in the low level quantization system with high sampling rate have an important application value for the progress in the digital measurement and processing field.

Control Effect of Slow-release, Long-acting and Multi-functional New Pesticides on Sugarcane Borders and Woolly Aphids

In order to select the long-acting,low toxic,low-risk and multi-functional new pesticides for the control of sugarcane borders and woolly aphids and precise and efficient application technology,the control effect of 10% monosultap · thiamethoxam granular formulation and 1% Bt · clothianidin granular formulation on sugarcane borders and woolly aphids were studied.The results showed that 10% monosultap·thiamethoxam GR and 1% Bt·clothianidin GR had good control effects on sugarcane borders and woolly aphids.They were ideal slow-release,long-acting,low toxic and multi-functional new pesticides used to control sugarcane borders and woolly aphids.They could be used alternately with other pesticides to delay the emergence and development of pest resistance to pesticides.The best dosage of the two pesticides in the field was 45 kg/hm^2.They could be mixed with fertilizer( 1200-1800 kg/hm^2),scattered in sugarcane ditches or at the base of sugarcane plants,and covered with soil or film from January to July.The control effect on dead heart seedlings damaged by borers could be up to above 79.2%,and the control effect on sugarcane woolly aphids could reach more than 98.8%.In comparison with the control group,the actual yield and sugar content of sugarcane increased by above 41 555 kg/hm^2 and 6.5% respectively.The application of slow-release,long-acting,strong systemic and multi-functional new agents with fertilizer around roots is convenient,precise and efficient,labor-saving,time-saving and environmentally friendly,and is worthy of being widely applied in sugarcane areas.

Analysis of coverage problem under border effects in wireless sensor networks

Wireless sensor networks can be used to monitor the interested region by deploying dense sensor nodes. Coverage is a primary metric to evaluate the capacity of monitoring. In this paper, we focus on the coverage problem under border effects, where the sensor nodes are distributed in a circle-shaped region randomly. Under this scenario, we derive the expected coverage of the sensor node and the total network coverage provided by n sensor nodes accurately by probability. These findings are useful to determine the related parameters （sensing range, number of sensor nodes and radius of monitored region） for a specific network coverage ratio. Simulation results demonstrate that our analysis is correct and effective.

Border effect-based precise measurement of any frequency signal

Limited detection resolution leads to fuzzy areas during the measurement, and the discrimination of the border of a fuzzy area helps to use the resolution stability. In this way, measurement precision is greatly improved, hence this phenomenon is named the border effect. The resolution fuzzy area and its application should be studied to realize highresolution measurement. During the measurement of any frequency signal, the fuzzy areas of phase-coincidence detection are always discrete and irregular. In this paper the difficulty in capturing the border information of discrete fuzzy areas is overcome and extra-high resolution measurement is implemented. Measurement precision of any frequency-signal can easily reach better than 1 × 10^-11/s in a wide range of frequencies, showing the great importance of the border effect. An in-depth study of this issue has great significance for frequency standard comparison, signal processing, telecommunication,and fundamental subjects.

“一带一路”背景下人民币跨境流通的OFDI效率提升效应

人民币跨境流通是中国跨国企业对外直接投资的载体,其流通水平对投资效率的影响机制值得研究。本文基准回归结果显示,人民币跨境流通能够提升中国对“一带一路”沿线国家的OFDI效率。进一步研究表明,人民币跨境流通对“一带一路”倡议提出后的中国OFDI效率有显著正向促进作用,对“一带”沿线国家、高制度质量国家和高经济发展水平国家的中国OFDI效率均有显著的正向影响;人民币跨境流通对中国OFDI效率影响的汇率传导机制成立,表现为负向弱化作用。中国应当强化与“一带一路”沿线国家金融服务基础设施建设合作,推动投融资便利化,加强制度合作,提升投资效率。

Poverty Reduction Effects of China’s Aid and Investment to Developing Countries

The Chinese approach to poverty reduction is a government-led and marketbased approach that gives priority to infrastructure and combines fiscal subsidy with development as an antidote to poverty.These characteristics are also evident in China’s cooperation with other developing countries on poverty reduction.China supports other developing countries to reduce poverty via aid and investment mainly in the field of infrastructure.While the government and SOEs take the lead in foreign aid and investment,China also invites other sources of capital to participate in market-based development in partnership with recipient countries.Our empirical research finds that aid and investment from China are generally conducive to reducing poverty incidence in recipient developing countries,but their poverty reduction effects vary across different types of aid and investment.The elements characteristic of the Chinese approach to poverty reduction proved to be effective in helping other developing countries reduce poverty as well.Nevertheless,the effectiveness of aid and investment in reducing poverty is subject to the governance and market efficiency of recipient countries.In order for the Chinese experience to work in less developed countries,future cooperation on poverty reduction must put a premium on governance and market systems.

金属预埋吊件的拉拔力学性能试验研究

为研究金属预埋吊件(简称预埋吊件)的拉拔力学性能和破坏机制,考虑无边距和有边距效应的影响,研发了一套拉拔加载装置,设计并完成了预埋吊件混凝土试件的拉拔试验。其中无边距影响的预埋吊件混凝土试件采用了5种预埋吊件,有边距影响的预埋吊件混凝土试件采用了3种预埋吊件,并运用ABAQUS模拟无边距影响的试件拉拔试验进行验证。结果表明:无边距影响的预埋吊件中销栓型预埋套筒、锚杆型内螺纹套筒以及锚筋型内螺纹套筒发生了预埋吊件拉断破坏,双头预埋吊杆试件发生了劈裂破坏,锚板型预埋套筒发生了理想的混凝土锥体破坏;有边距影响的混凝土预埋吊件均发生混凝土锥体破坏。

粤港澳大湾区交通流网络空间结构和边界效应测度

推动港澳与内地交通互联互通和融合发展是粤港澳大湾区高质量发展的重要内容。大湾区由于制度差异对跨境交通产生边界效应,但现有研究中利用真实交通流大数据对边界效应的动态测度研究不足。文章基于粤港澳大湾区高速公路收费数据和跨境交通数据构建大湾区交通流网络,采用复杂网络和边界效应度量方法,研究大湾区交通流网络空间结构及其边界效应的动态变化。结果表明,粤港澳大湾区交通流网络具有独特的广佛、深莞惠“双核心―边缘”结构,疫情后大湾区交通流网络的交通覆盖度和紧密度都有较大提升,港澳车流开始跨越边界向北延伸,粤港澳交通融合加速,形成“两岸互通、全域互联”的空间格局,但整体上香港地区和澳门地区在整体网络的重要性依然较弱。香港地区和内地、澳门地区和内地间的阻碍系数高于内地各县区间的阻碍系数,客车的阻碍系数普遍低于货车的阻碍系数。疫情后全网络的阻碍系数呈现动态下降趋势,边界效应的限制作用降低。文章拓展了交通流网络研究中边界效应的定量研究框架,有助于推动粤港澳大湾区交通融合发展。

企业跨国并购与离岸外包对技能溢价的影响探讨

全球化时代,不同国家(地区)之间的企业跨国并购行为较为常见,对企业管理、技术、人员等产生深远影响。研究基于我国上市公司相关数据,构建双固定效应模型,实证分析了跨国并购、离岸外包对企业技能溢价的影响。结果显示,跨国并购对企业技能溢价具有显著的正向影响,离岸外包在跨国并购对企业技能溢价的影响中具有部分中介作用。

杭州地区长效低维护优良花境植物材料筛选及应用研究

选取杭州地区5处典型花境样地,通过长期实地跟踪调查,依据筛选原则,共筛选出了适合杭州地区推广应用的长效、低维护优良花境植物材料118种。同时,总结了杭州地区长效型花境应用的特点,并进一步尝试提出了优化的对策及建议,以期为杭州长效型花境的健康发展及推广应用作出贡献。

跨境电商对我国经济增长的影响——基于省级面板数据实证分析

跨境电商作为贸易新业态,能够很好地改善传统贸易方式、激发国内市场活力、扩大国内市场需求,同时也为促进我国经济增长注入新活力。采用我国2012—2021年省级面板数据,通过构建跨境电商指标体系,研究跨境电商对于我国经济增长的影响效应,同时还采用门槛效应模型来研究跨境电商交易额对我国经济增长是否存在非线性关系。研究结果表明,在做基准回归时,跨境电商对我国经济增长具有显著的促进作用。考虑控制变量的情况下,促进作用仍然存在。将跨境电商划分行业发展、运输物流、政策管理三维度,分别研究对我国经济增长影响,结果表明都产生显著的正向影响。在进行面板门槛效应回归时发现,跨境电商交易额对我国经济增长存在单一门槛效应,超过门槛值影响系数变大,表明跨境电商交易额对我国经济增长存在边际效用递增的影响。从加大跨境电商综合试验区的设立、推进跨境电商基础设施建设、推进跨境电商技术人才培养以及提升互联网信息化水平这四个方面提出完善跨境电商发展的相关建议。

RCEP背景下黑龙江省跨境电商发展存在的问题与对策

RCEP为成员国之间的自由贸易扫清了障碍,促进了跨境电商的蓬勃发展,并使之成为各成员国竞争与合作的新领域。在此背景下,黑龙江省跨境电商发展势头迅猛,成效显著,但同时在RCEP背景下也面临着新的机遇和挑战。为了抓住新的发展契机,黑龙江省亟须解决影响跨境电商高质量发展的问题,主要包括物流成本高、企业竞争力相对薄弱、人才短缺和产业集聚效应不明显等,并提出解决问题的对策,以期充分利用RCEP带来的机遇,推动黑龙江省跨境电商产业的健康发展。

跨境资本与人民币汇率的非对称波动耦合效应

构建向量误差修正‒广义自回归条件异方差‒非对称BEKK(VECM-GARCH-ABEKK)模型,从产业资本和金融资本两个维度,研究跨境资本与人民币汇率波动的非对称耦合效应。研究发现,产业资本和金融资本与人民币汇率具有显著的持续性、集聚性波动特征,且两类跨境资本与人民币汇率之间的波动溢出存在差异化的非对称耦合效应。研究提出优先针对产业资本外流风险出台相关政策,构建“宏观审慎+微观监管”监管框架,降低外汇市场超调风险,利用人民币离岸交易构筑资本跨境流动缓冲区等对策建议。

并购情境下基于智力资本整合的技术追赶机理———沈阳机床并购德国希斯案例分析

跨国并购被认为是后发企业获取创新资源实现技术追赶的有效捷径。对被并方资源形式拥有并不等于技术能力提升,有效内化并购资源才能支持后发企业技术能力跃升。但文献对“并购-技术追赶”的资源整合的动态机制缺乏充分理论解释。将沈阳机床并购德国希斯的整合实践作为案例样本,借鉴与组织技术转移和创新关联性较强的“智力资本”概念体系,探索基于并购的“智力资本整合-技术追赶”内在机理。研究发现:①基于并购的技术追赶遵循“吸收模仿-集成创造-主导领先”发展路径;②“并购追赶”导向下智力资本整合呈现“人力资本整合主导-社会资本整合主导-组织资本整合主导”演进轨迹;③智力资本整合效应呈现“逆向吸收效应-多元融合效应-能力重构效应”动态转变。

省际边界对产业结构演变的影响——以淮海经济区为例

利用产业结构差异度模型和空间杜宾模型探究2005-2020年淮海经济区省际边界对产业结构演变的影响效应及作用机理。结果表明:①研究期内淮海经济区产业结构层次不断提升,空间上由低水平均衡转变为极化发展;②研究期内省际边界的影响效应由切变效应逐渐转化为中介效应,切变效应在空间上由中间向外围转移;③行政干预是形成人为边界的重要原因,会加强淮海经济区省际边界的切变效应,人均GDP的提高是省际边界切变效应逐渐转化为中介效应的重要原因之一,但人均消费品零售额的提高则会抑制这种转化,而人均全社会固定资产投资额对切变效应的影响不大。最后,根据研究结果从产业发展、协同合作等方面提出建议。

中巴经济走廊影响双边贸易边境效应的GSIM模型测度

为了测算中巴经济走廊对新疆及巴基斯坦贸易边境效应的影响,本论文采用《世界银行》以及《新疆统计年鉴》农产品贸易数据,构建了2012—2017与2018—2021年两期贸易局部均衡模型(GSIM),测算结果显示:新疆与巴基斯坦贸易边境效应由2012—2017年间的25%,下降到2018—2021年间的20%,意味着走廊降低了新疆与巴基斯坦的贸易壁垒。2012—2021年间出口边境效应下降幅度比进口边境效应下降更多,说明10年间新疆出口贸易的增长要高于进口贸易的增长,表明新疆与巴基斯坦出口贸易潜力逐步释放,新疆提供的贸易便利化更多。新疆与巴基斯坦双边贸易边境效应下降主要归因于贸易政策的深化,经济活力增强,全要素生产率增强。2018—2021年间新疆与巴基斯坦的贸易成本相对于2012—2017年间降低了10.62%。走廊加深了巴基斯坦与新疆的相互贸易依存度,提升了双边贸易水平,削弱了贸易壁垒,降低了双边贸易成本以及对本土产品的偏好。

基于合成控制模型的广东省跨境电商政策效应评价研究

本文以广东省佛山、珠海、东莞、汕头构建实验组,并以2019年为政策干预期,利用合成控制法对广东省四市的跨境电商综试区政策效应进行分析。结果显示:从跨境电商综试区政策效应方面看,佛山及珠海在广东省跨境电商综试区政策出台后,对跨境电商行业产出水平方面具有显著的提升作用;从政策效应的城市差异层面看,广东省跨境电商综试区政策出台后对地理位置、产业基础及资源禀赋具有优势的城市促进作用最为显著,而对上述优势不明显的城市促进效果不显著。

数字经济对我国跨境贸易高质量发展的实证研究

基于2011-2021年我国30个省份的面板数据,采用熵值法测度数字经济发展水平及跨境贸易高质量发展水平。通过构建双固定效应模型和中介效应模型,探究数字经济对我国跨境贸易高质量发展的影响及内在作用机制。研究表明,数字经济对跨境贸易高质量发展的促进作用显著,且存在地区差异。技术创新在这一过程中发挥了中介作用,政府支持则产生正向调节效应。因此,应加大对数字经济的支持力度,加强技术创新,因地制宜地发展数字经济,以全面赋能我国跨境贸易高质量发展。

跨境电商综试区设立能否赋能企业数字化转型?

跨境电商综试区作为培育新产业、新业态的制度型开放高地,通过发挥政策红利能够为产业数字化发展提供新动能。文章以2011—2022年中国上市公司数据为研究样本,基于跨境电商综试区设立的准自然实验,利用多期双重差分法系统评估跨境电商综试区设立对企业数字化转型的影响。稳健的经验研究表明,跨境电商综试区设立显著促进了企业数字化转型,相较于非试点地区,跨境电商综试区设立使得本地企业的数字化转型程度提升8%;机制分析表明,跨境电商综试区设立通过改善地区产业结构、加剧市场竞争程度、激励企业研发创新、降低企业交易成本以及缓解企业融资约束推动企业数字化转型;异质性分析表明,跨境电商综试区设立对高技术行业企业以及位于经济发展水平较低地区的企业数字化转型的促进作用更为显著。文章研究对进一步夯实中国跨境电商综试区建设成效,加快企业数字化转型进程具有重要的决策参考价值。