我国现代农业发展的现状、问题与对策研究

近年来,在科技支撑和制度支持的背景下,我国的现代农业得到了长足发展,取得了举世瞩目的成绩。但是在发展过程中也出现了很多问题,例如:与发达国家相比,科技装备相对落后,现代农业人才严重短缺,金融支持力度不足,市场机制不完善等,因此深入研究现代农业具有重要的现实意义。文章首先对何为现代农业进行了详细阐述;然后分析了我国现代农业发展的现状;再次分析了我国现代农业发展中存在的主要问题;最后提出了切实可行的对策,为现代农业发展提供一些参考,促进现代农业科学发展。     

皮带运输机皮带跑偏成因及解决办法

为保障皮带运输机的安全运作,避免跑偏状况出现,本文针对皮带运输机的结构和工作原理进行分析,详细研究了可能引起皮带跑偏的一些原因,并针对原因提出了相应解决办法.     

事业单位财务档案管理体系建设研究

随着事业单位经济活动不断拓展,单位管理要与时俱进,不断创新,财务档案与经济活动息息相关,是事业单位管理的重要抓手,加强财务档案管理是提高事业单位经济管理能力的重要途径。文章立足事业单位,针对其管理特点,结合国家政策法规,详细介绍财务档案管理的必要性及管理现状,并通过管理实践,展示了财务档案管理流程和方法,是理论与实践的有机结合,对事业单位加强财务档案管理,提升整体管理水平具有重要借鉴意义。     

LT码新型度分布及其在电力线通信中的应用

Luby变换(Luby Transform,LT)码作为信道编码应用于电力线通信(Power Line Communication,PLC)，可实现电信号的可靠传输。度分布对LT码编译码性能的影响至关重要。为了得到更优的度分布，首先调整二进制指数分布(Binary Exponential Distribution,BED)中的度数比例，获得一种译码性能更优的改进的二进制指数分布(Improved BED,IBED)。然后，根据IBED在冗余度较小时译码成功率高，而冗余度增大后鲁棒孤子分布(Robust Soliton Distribution,RSD)的译码性能表现更佳的特点，通过求和归一化的方式将IBED与RSD两种度分布的优势进行有机结合，提出一种新型二进制鲁棒孤子分布(Binary RSD,BRSD)。仿真结果表明，与其他方法及传统的RSD相比，采用新度分布进行LT编码，可明显降低译码开销，并节约编译码耗时。将新型度分布应用于基于LT码的PLC系统中，能有效地抑制PLC信道中各种噪声对电信号的干扰，并提高通信效率。     

Why will Trump lose the trade war?

ABSTRACT

The escalating U.S.–China trade conflicts have increasingly shadowed the outlook of the world economy. The Trump administration aims to achieve its strategic goals including reducing current account deficits, promoting the U.S. manufacturing sector, and curbing Chinese high-tech industries by waging the trade war against China. This paper argues that the current account deficits and the declining manufacturing sector in the U.S. are mainly driven by its internal structural factors, such as low saving rates, high labor costs, and rising service sector, rather than by the import competition from China. Moreover, the trade war further deteriorates the U.S. current account deficits and erode its comparative advantage, and it forces China to invest more in technological innovation and human capital, and thus promote its progress in high-tech industries. Thus, the U.S. will not be able to achieve its strategical goals and eventually lose the trade war.     

R&D Investments and Tax Incentives: The Role of Intra-Firm Cross-Border Collaboration*

U.S. multinational corporations increasingly use intra-firm, cross-border research collaboration to disperse R&D across different countries. This paper investigates the implications of such collaboration on the abilities of firms to garner benefits from R&D tax incentives. We find that the association between R&D intensity and tax incentives is three to five times larger when firms have extensive cross-border collaboration connected to a country. We also find that the effect is stronger when local intellectual property protection is weaker and when local innovation resources are higher. Our results suggest that cross-border collaboration helps firms achieve more tax-efficient R&D investments both by reducing the nontax frictions posed by weak intellectual property protection and by increasing the nontax benefits of foreign R&D.     

县域特色产业集群高质量发展研究

县域特色产业集群的快速发展有效推动了当地经济发展,在市场中形成了规模优势和竞争优势,是构成经济持续发展的关键动力.但是当前在发展过程中出现了较多的问题,影响了其发展质量和发展速度,基于此,本文对县域特色产业集群的发展优势、发展问题和发展策略进行了分析,以期可以为其高质量发展提供有效参考,扩大发展规模.     

基于AD9361的掌上型LTE RRU设计与开发

当前小体积远端射频单元（Remote Radio Unit,RRU）主要是皮站级别的Pico-RRU，其重量和体积仍然难以满足掌上型的要求。为此，采用高集成度的AD9361芯片来实现长期演进（Long Term Evolution，LTE）宽带收发信机功能，配合时钟同步模块、放大器模块和控制接口电路等一起构建低成本的掌上型RRU。主要解决了基于AD9516的时钟同步、低相位噪声设计和高灵敏度接收机设计三个技术难点，成功实现了掌上型、高性能、低成本的设计目标。整个RRU样机尺寸为18 cm×10 cm×2 cm，质量约500 g，量产成本千元以内。测试表明，该RRU下行误差向量幅度（Error Vector Magnitude，EVM）小于3%，优于3GPP要求的8%；10 MHz带宽时上行接收机灵敏度优于3GPP要求的-93.5 dBm。     

Fiscal decentralization, revenue and expenditure assignments, and growth in China

Theory suggests that a close match between revenue and expenditure assignments at sub-national levels benefits allocative efficiency, and hence economic growth. That is, a convergence of revenue and expenditure assignments at sub-national levels of government should, according to the theory, be positively associated with a higher growth rate. In the case of China, this paper shows, divergence, rather than convergence, in revenue and expenditures at the sub-national level of government is associated with higher rates of growth. A panel dataset for 30 provinces in China is used to examine the relationship between fiscal decentralization and economic growth over two phases of fiscal decentralization in China: (1) 1979–1993 under the fiscal contract system, and (2) 1994–1999 under the tax assignment system. The seeming contradiction between the theory and evidence in the China case is reconciled by taking into account the institutional arrangements that prevailed during the two phases of fiscal decentralization, in particular the inconsistency between the assumptions of the theory of fiscal decentralization and the institutional reality of China.     

工商管理学科实验教学体系研究

在追溯工商管理学科实验方法发展历史进程的基础上,分析了工商管理学科4种实验教学模式的特点,系统研究了我国高校工商管理学科实验教学的具体构架。