Analysis on the Climatic Change Characteristics of the Snow Cover Days and Its Influence Factors in Suzhou during Recent 50 Years

[Objective] The research aimed to study climatic variation characteristics of snow cover days and its influence factors in Suzhou of Anhui Province during recent 50 years. [Method] According to annual snow cover days and correlated data in Suzhou during 1961-2010, by using linear trend method, accumulative anomaly and complete correlation coefficient method, etc., the climatic variation characteristics of snow cover days and its influence factors in Suzhou were analyzed. [Result] In recent 50 years, the snow cover period in Suzhou presented shortened trend. Except days of snow cover (≥20 cm), the annual snow cover days at each thickness all showed varying degrees of decrease trend. The annual snow cover days had wavy decline trend, and the decline amplitude was 0.84 d/10 a. From the 1960s to prior period of the 1970s, the annual snow cover days presented increase trend. From middle and later periods of the 1970s to middle period of the 1980s, the snow cover days was less and gradually increased from later period of the 1980s to the early 1990s. From middle period of the 1990s to 2003, it entered into less snow period again. From 2004 to now, it presented oscillation of snowy and less-snow alternating. The main climatic factor which affected annual snow cover days in Suzhou was average temperature. The second one was average surface temperature. [Conclusion] The research provided theoretical basis for analyzing climate variation in Suzhou under the background of global climate warming.

Numerical study on the wave pattern characteristic of air layer in cavity and the effects of multiple influence factors

Air-layer drag reduction (ALDR) technology for ship energy saving is getting more and more attention in recent years because of the outstanding drag reduction effect. In order to promote practical application, it is necessary to fully understand the two phase flow characteristics of the air layer. Recent experimental studies have shown that the surface of the air layer presents wave pattern, which has an important influence on its damage risk. However, it is difficult to measure the wave pattern quantificationally due to the interference of equipment. The main goal of the present paper is to investigate the wave pattern characteristic of air layer in cavity using numerical simulation method. On this basis, the effect of flow and geometric influence factors are discussed to understand the key control conditions. A computational fluid dynamics (CFD) numerical method based on Reynolds averaged Navier-Stokes (RANS) equations and volume of fluid (VOF) interface capturing method is established, and has been successfully applied in the simulation of air layer wave pattern. Both 2-D and 3-D simulations are carried out, aiming at analyzing air-water interface flow and vortex flow directly. Based on the simulation results, several important conclusions about the mechanism of air layer wave pattern can be obtained. Firstly, it is found to be an inherent characteristic that the wave height of the upstream air layer is higher than that of the downstream. The extremely high wave peak is easy to contact with the flat plate, leading to the breakup of air layer and a “central blank area” phenomenon. With the help of flow analysis, it is found that this characteristic is mainly caused by the strong counterclockwise vortex behind the bow wedge block. Secondly, the air layer stability is reduced with the increase of water flow velocity by affecting the wave height. There is a saturation point of air flow rate to reach maximum thickness of air layer. Thirdly, cavity configuration has obvious influence on air layer stability by influencing vortex flow field. The increase of cavity depth and width can aggravate the unsteady and nonlinear characteristics of air layer. Finally, comprehensive design criteria are concluded from the view of geometrical configuration and flow conditions. A cavity with the moderate depth and width can avoid the upstream damage of air layer. Longitudinal position of air nozzles should be set within the low pressure zone behind the wedge block for stable air layer formation.

Social and Linguistic Factors' Influences on Semantic Change in English Vocabulary

this paper aims to analyze the social and linguistic factors' influence on semantic change in English vocabulary. Mainly speaking, the social factors include social development, social context, social class, national feeling, racial feeling, gender different, and social value, and linguistic factors consist of generalization, specialization, amelioration, pejoration, metaphor and metonymy.

Study on the Influencing Factors of Chemotherapeutic-Related Taste Changes in Cancer Patients

Objective: To investigate the current situation of chemotherapy-related taste changes of cancer patients in Jingzhou area, and analyze the influencing factors of chemotherapy-related taste changes of cancer patients. Methods: In this study, 233 patients with malignant tumors who were confirmed by pathological examination and expected survival time of more than 6 months after admission to a tertiary general hospital in Jingzhou from January 2018 to October 2018 were selected by convenience sampling method. The Chinese version of The chemotherapy-induced Taste Alternation Scale (CiTAS) was used to investigate the baseline data and occurrence status, and multiple regression analysis was used to explore the influencing factors. Results: In this study, 171 tumor patients experienced chemotherapy related taste changes, accounting for 73.4% (171/233);The vast majority of chemotherapy patients have different types and severity of taste changes;Multiple regression analysis showed that the duration of chemotherapy, the number of consecutive days of chemotherapy, and dry mouth were the main influencing factors for chemotherapy related taste changes in cancer patients (p Conclusion: Nursing personnel should pay attention to the occurrence of chemotherapy-related taste changes in tumor patients, and provide predictive nursing interventions to improve their taste experience for tumor patients who have a long course of chemotherapy, many consecutive days of chemotherapy, or have dry mouth conditions.

Factors affecting land dissection density in geomorphological regions of China

Land dissection density(LDD)provides morphological evidence regarding prior intense soil erosion and quantifies the distribution of land dissections.A comprehensive understanding of the potential factors influencing the spatial pattern and value of the LDD is vital in geological disasters,soil erosion,and other related domains.Land dissection phenomena in China affects large areas with different morphological,pedological,and climatic characteristics.Prior studies have focused on the potential factors influencing the LDD at a watershed scale.However,these results are insufficient to reflect the status quo of dissection development and its primary influencing factors on a national scale.LDD’s spatial patterns and the dominant factors at a regional scale in millions of square kilometers remain to be ascertained.This study used the geomorphon-based method and the geographical detector model to quantify the spatial pattern of LDD over China and identify the dominant factors affecting this pattern in China’s six first-order geomorphological regions(GR1~GR6).The results yield the following findings:(1)LDD in China ranges from 0~4.55 km/km^(2),which is larger in central and eastern regions than in other regions of China;(2)dominant factors and their dominant risk subcategories vary with each geomorphological region’s primary internal and external forces;(3)the influence of natural factors is more significant on the large regional scale in millions of square kilometers compared to anthropogenic factors;relief degree of land surface(RDLS)is dominant in GR1,GR2,and GR5;the slope is dominant in GR6,soil type is dominant in GR3 and GR4,and lithology plays a critical role in the dominant interactions of GR3,GR4,and GR6;(4)the interactions between factors on LDD’s spatial pattern have a more significant effect than individual factors.

Study on the Spatiotemporal Pattern Evolution and Influencing Factors of Population Aging in Henan Province

This study utilized census data from Henan Province for the years 2000,2010,and 2020 to investigate the spatiotemporal evolution of population aging,defined by the proportion of the population aged 65 and above.Employing spatial analysis techniques such as spatial autocorrelation and the standard deviation ellipse,the research mapped out the progression and distribution of aging demographics.Furthermore,the study delved into the influencing factors of aging using an optimal parameters-based geographical detector.Results indicate a deepening degree of population aging in Henan Province,transitioning from an adult type to an old type structure.There is a marked positive spatial correlation among counties,with high-value aging areas initially decreasing,then increasing,and notably spreading from the central to the central and southern regions of the province.The center of gravity for population aging,specifically around Changge City and Xuchang City,exhibits a trajectory moving southeast before shifting northwest.Factor detection reveals that in 2000,2010,and 2020,the elderly dependency ratio predominantly influences the aging trend,with explanatory powers of 88.4%,87.9%,and 90.9%,respectively.Interaction analysis indicates that the interaction between the old-child ratio and the elderly dependency ratio has a strong explanatory power for the aging patterns in Henan Province,reaching 97.3%,97.0%,and 97.4%,respectively.

Relationship Between Diurnal Changes of Net Photosynthetic Rate and Influencing Factors in Rice under Saline Sodic Stress

The net photosynthetic rate of flag leaves and influencing factors under saline sodic soil conditions were investigated at the full heading stage of rice. The net photosynthetic rate of rice leaves showed a double-peak curve in a day in both non-saline sodic and saline sodic soil treatments. The first peak of the net photosynthetic rate appeared at 9：00-10：00 and 9：00 in the saline sodic and non-saline sodic soil treatments, respectively, whereas the second peak both at 14：00. The midday depression of the net photosynthetic rate always appeared regardless of non-saline sodic or saline sodic soil conditions. In addition, the net photosynthetic rate significantly decreased in all day under saline sodic conditions compared with that under non-saline sodic conditions. Some differences were observed in correlation characters between the net photosynthetic rate and all influencing factors during 9：00-13：00. Under non-saline sodic conditions, the diurnal changes of the net photosynthetic rate in a day were mainly caused by stomatal conductance, and the limitation value and the stomatal factors served as determinants; whereas under saline sodic stress, the diurnal changes of the net photosynthetic rate in a day were mainly caused by non stomatal factors including light intensity and air temperature.

Changes and Influencing Factors of Maize Production Pattern in China

Since the founding of new China,the maize production pattern took on characteristic of " northern expansion and western movement" : there were great changes in ranking of main producing provinces; southern planting area gradually shrank,while central and northern planting area gradually expanded; apart from traditional main producing regions such as northeastern,north China,and southwestern regions,Shanxi- Shaanxi region and northwest region are gradually forming. To further analyze factors promoting changes in maize production pattern,based on 1987- 2013 panel data,we carried our empirical study and obtained five influencing factors: resource endowment,economic environment,market environment,technical conditions,and policies. Per capita farmland,multiple cropping index,water conservancy and irrigation,and benefit cost ratio,and traffic and transportation policies exert positive effect,non-agricultural employment level exerts negative effect,and the significance of natural disasters,market price,and science and technology are inadequate.

Analysis of the Influencing Factors of Changes in Foxtail Millet Planting Area in Hebei Province

Since reform and open to the outside world,foxtail millet planting area in Hebei Province has constantly reduced,and its planting region has changed from the whole province into some regions,with obvious changes. In this paper,by using qualitative and quantitative approaches like chart analysis,summarizing,Delphi method and osculating value model,the influencing factors of changes in millet growing region in Hebei Province were studied. The results showed that the changes of millet planting area were closely related to many factors,such as little investment in scientific research,weak policy support,a single consumer product demand,the rapid development of other staple crops, labor migration,relatively low comparative effectiveness and physiological characteristics of the millet itself. Then some suggestions were put forward,such as increasing research support,strengthening scientific research strength,researching and developing deeply processed products, expanding consumer groups,improving millet policy support,providing subsidies for planting the improved varieties,researching and developing various types of machinery,and increasing millet production technology training.

Regional Differentiation Regularity and Influencing Factors of Population Change in the Qinghai-Tibet Plateau, China

The Qinghai-Tibet Plateau(QTP) is the most unique region of human-land relations, and its main factor is population. By building a population and space dataset of the QTP at the township level from 1982 to 2017, this paper presents the pattern evolvement and regional distribution characteristics of township-level population in the QTP in detail for the first time. By using Geodetector method to analyze the influencing factors of township-level population change in the QTP, this paper provides scientific foundations for studying the Third Pole, ecological environment protection of the QTP, and human-land relations. The conclusions are as follows:1) The population spatial distribution is not balanced at the township level, presents the regional differentiation characteristics of ‘dense in southeast and sparse in northwest’ along the ‘Qilian-Jilong Line’, and demonstrates the phenomenon of population center of gravity moving to the hinterland of the plateau at an accelerated speed;2) The township-level population develops in a decentralized trend in general, and the cold-and hot-spot distribution of population has prominent spatial distribution characteristics. The population hot spots are concentrated in the surrounding areas of Xining, Golmud, Hotan and Lijiang;3) The population of the QTP is increasing, and the inter-annual change of township population has a relatively stable regional regularity;4) The level of per capita income is the leading factor in the change of township population, and its effect intensity is increasing continuously. The relative effect intensity of urbanization level and location conditions on population change has decreased significantly after 2000. The adaptability of living environment,such as topography and climate, has little influence on population change.

Dynamic change of agricultural energy efficiency and its influencing factors in China

In order to practice the concept of‘lucid waters and lush mountains are invaluable assets’and promote the green development of agriculture,it is necessary to improve the efficiency of agricultural energy utilization.Based on the panel data of 28 provinces from 1995 to 2018,this paper calculated China’s agricultural energy input from two categories of direct energy and indirect energy,and used EBM(Epsilon-based Measure)mixed distance function model to measure the energy efficiency of agriculture in China.The nuclear density function and spatial autocorrelation were used to analyze the dynamic evolution of agricultural energy efficiency,and the dynamic panel model was used to analyze the influencing factors of agricultural energy efficiency.The results showed that:①From 1995 to 2018,the total agricultural energy input had increased year by year in China,with an average annual growth rate of 2%.Energy input structure changed from indirect energy-based to direct energy-based.Agricultural energy efficiency showed an evolutionary trend of‘rising-stagnating-rising rapidly’in China.The agricultural energy efficiency was generally low in China,and there was a large space for improvement in agricultural energy efficiency.②From 1995 to 2018,the average annual growth rate of agricultural energy efficiency in the eastern,central and western regions was 2.7%,1.9%and 1.4%respectively.In 2018,the agricultural energy efficiency in the eastern,central and western regions was 0.81,0.71 and 0.59 respectively.The gap between regions was expanding rapidly,and the agricultural energy efficiency in the central and western regions needed to be improved.③From 1995 to 2018,the agricultural energy efficiency of each province was polarized and the absolute gap was widened.There was obvious improvement in agricultural energy efficiency in Guangdong,Shandong,Jiangxi,Jiangsu,Liaoning and Tianjin,while the agricultural energy efficiency of Xinjiang,Guizhou,Zhejiang,Shanghai,and Inner Mongolia deteriorated.④From 1995 to 2018,there was no global spatial correlation of China’s agricultural energy efficiency.However,local‘high-high’concentration gradually appeared in the eastern region since 2010.⑤The first lag of energy efficiency had a significant positive impact on agricultural energy efficiency,and agricultural energy efficiency improvement had a time lag.The level of human capital,per capita net income of farmers and the level of urbanizaton had a significant positive impact on agricultural energy efficiency.The disaster rate,the level of development of secondary and tertiary industries,and the level of opening up had a significant negative impact on agricultural energy efficiency.In the implementation of the strategy of rural revitalization,we should focus on the central and western regions,take the cultivation of professional farmers as the key,focus on improving agricultural production conditions,enhance the level of cooperation between regions,exert the leading role of the secondary and tertiary industries,and enhance the ability of agricultural disaster prevention and mitigation.

Analysis on Change Trend and Influencing Factors of Natural Resource Utilization of Community Farmers around the Habitat of Giant Pandas

The habitat of giant pandas borders the living areas of farmers in surrounding communities. Due to the low level of economic development and resource used method, the life of community farmers depends on the natural resources of the habitat of giant pandas. Analyzing the natural resource utilization of farmers in communities around the habitat of giant pandas is conducive to formulating more reasonable management policies and protecting the habitat of giant pandas more effectively. Based on the field survey data, this paper classifies the main ways of community farmers using the natural resources of the habitat of giant pandas, counts the quantity of resources used and analyzes their change trends. On this basis, this paper selects indicators, constructs a model and analyzes the main influencing factors affecting the natural resources utilization of community farmers from three aspects: the individual characteristics of household heads, the family characteristics of community farmers and the residence characteristics of community farmers.

Spatiotemporal Pattern of Cultivated Land Pressure and Its Influencing Factors in the Huaihai Economic Zone, China

Cultivated land pressure represents a direct reflection of grain security. Existing relevant studies rarely approached the spatiotemporal pattern of cultivated land pressure or the spatial heterogeneity of its influencing factors from the level of economic zones.Taking the Huaihai Economic Zone(HEZ), China for case analysis, this study investigated the spatiotemporal pattern of cultivated land pressure in diverse periods from 2000 to 2018 based on a modified cultivated land pressure index and spatial correlation models. On this basis, it explored the influencing factors of the spatial differentiation of cultivated land pressure in the late stage of the study using geographical detector as well as multi-scale geographically weighted regression model. The results indicated that: 1) in the study period, the global cultivated land pressure index of the study area decreased gradually, but cultivated land pressure increased locally in a significant way, especially in the central and southern Shandong Province;2) the spatial pattern of cultivated land pressure manifested global clustering features. Hot and secondary-hot spots presented a narrowing and clustering trend, whereas cold and secondary-cold spots manifested a spreading and clustering trend;3) average slope, the proportion of non-grain crops, population urbanization rate, and multiple cropping index have significant effects on the spatial differentiation of cultivated land pressure. The former three factors were positively correlated with cultivated land pressure, and the last factor was negatively correlated with cultivated land pressure;and 4) the amount of cultivated land has increased in the central and southern Shandong Province through land consolidation which, nonetheless, failed to improve the grain production. In regards to major grain producing areas similar to the HEZ in China, the authors suggest that great importance should be given to the balance of the quality and quantity of cultivated land, the optimization of agricultural production factors and the rational control of non-grain crops, thus providing a powerful guarantee for grain security in China.

Factors Influencing Migrant Workers' Urban Labor Patterns: Willing Working Time in Urban Areas as the Mediator

China is witnessing a very complicated economic development environment.Migrant workers'working patterns will directly affect their income level and the realization of many economic and social development goals.This paper collects relevant data from three places:Shanghai,Lanzhou and Chengdu for empirical research whose results show that determinants of migrant worker's willing working time in urban areas mainly include the“income-consumption difference”,“urban-rural consumption difference”and their“urban income and expenditure uncertainty”.These factors directly affect their effective working time in the city,and determine their choice of choosing corresponding work patterns.From the significant differences of these factors,we can see that migrant workers in China is still struggling to solve their material needs under the pressure of livelihood,and less attention is paid to their spiritual needs and the pursuit of quality of life.

2001-2020年山东省花生生产地域格局变化及影响因素

基于2001-2020年统计数据,运用数理统计和区域差异法,分析了山东省花生生产地域格局的变化特征及其影响因素,为山东省花生生产的可持续发展提供科学决策依据。研究表明,近20年来,山东省花生生产呈“两减一增”局面,面积和产量分别下降33.00%和22.34%、单产增加15.93%;花生生产区域向以临沂为中心的鲁西南地区和烟台、威海、青岛所处的胶东东部地区集中;20年中有4年花生面积贡献率大于单产贡献率,有16年小于单产贡献率。研究发现,鲁东和鲁西南地区经济作物面积占比减少,是导致山东省花生种植面积下降的直接影响因素;山东花生净利润和成本利润率降低,特别是近年来的“断崖式”下跌,是导致花生种植面积和总产量逐年下降的根本原因;国内外贸易市场不稳定带来的风险,也制约了花生产业的发展。

中国旅游产业链发展格局演变及空间效应研究

产业链现代化是建设现代化产业体系及助推中国式现代化进程的重要抓手,全面揭示旅游产业链发展现状及其影响因素对于提升旅游产业链现代化水平具有实际意义。该文以2001-2019年中国30个省域为研究对象,构建涵盖旅游供需链、企业链、空间链、价值链的旅游产业链发展水平评价指标体系,利用核密度估计、Dagum基尼系数及其分解、探索性空间数据分析等方法对中国旅游产业链发展的时序演变规律、空间差异特征及空间关联格局进行分析,并运用空间杜宾模型探讨影响中国旅游产业链发展的主要因素及其空间效应。研究发现:(1)中国旅游产业链发展水平呈平稳提升态势,表现出由东部地区向中部、东北及西部地区递减的分布态势。(2)中国旅游产业链发展的总体区域差异呈波动缩小趋势,区域间差异是其主要来源,且东部与西部地区旅游产业链发展的区域间差异最大;东部地区旅游产业链发展的区域内差异最大,西部、东北地区次之,中部地区最小。(3)中国旅游产业链发展具有空间相关性和空间集聚特征,供给、需求、创新、政策等层面因素是影响中国旅游产业链发展的主要因素。其中,旅游资源禀赋、旅游人力资本、互联网、产业融合发展与对外开放水平有利于推进本地区旅游产业链发展,旅游需求总量、旅游需求结构与对外开放水平能通过正向空间溢出效应带动邻近地区旅游产业链发展。

流域视角下安徽省传统村落时空格局差异性研究

选取安徽省内淮河流域和长江流域传统村落为研究对象,从时间和空间两个维度分析传统村落演化差异性并探究影响传统村落分布的主要驱动因子。结果表明:(1)在时间维度,在历史发展进程中传统村落差异明显。淮河流域经历“萌芽期—雏形期—形成期—饱和期—平缓期”,传统村落以农耕生活方式平稳发展。长江流域经历“萌芽期—雏形期—发展期—转变期—鼎盛期”,传统村落以经商生活方式迅速发展;(2)在空间维度,传统村落重心迁移路径均为由北向南,但空间格局特征差异性显著。淮河流域传统村落主要聚集在耕地密集的淮河北岸但聚集度较低,分布聚集度先减小后增加。长江流域传统村落显著聚集在长江南岸,分布聚集度持续增加;(3)两流域内传统村落均主要分布在低海拔、低坡度、邻水系及气候适宜的地区,不同历史时期气温和降水是影响传统村落空间分布的主要驱动因子,长江流域传统村落受高程影响程度高于淮河流域。长江流域内现存传统村落空间分布受地均GDP和人口密度影响程度高于淮河流域内传统村落。

黄河流域气溶胶时空异质性及影响因素分析

基于大尺度黄河流域的长时序气溶胶光学厚度(AOD)的分析较少,且因素分析也集中在气象条件方面,针对该问题,搜集了MODIS气溶胶产品数据,基于地理加权回归模型(GWR)分析了整个黄河流域的时空变化特征,定量探讨了地理环境、自然气象和社会经济对AOD的综合影响。结果表明:黄河流域AOD整体为下降趋势,由2001年的0.38下降至2020年的0.22。AOD的变化具有明显的季节性,春夏季高于秋冬季,这可能是气温、大气扩散条件和植被覆盖等因素共同作用的结果;从空间分布角度来看,研究区AOD为自西向东呈现梯度递增分布,与流域DEM分布趋势相反,说明地形与气溶胶之间有密切关联。基于GWR模型的研究结果表明:地形植被对整个黄河流域AOD影响程度最大,其次为社会经济、自然气象。针对黄河流域内重点城市的研究结果表明:不同城市气溶胶光学厚度的月际变化有较大差异,流域上游城市西宁、银川和包头的AOD水平较低,冬季AOD最高,夏季AOD最低,而中下游城市夏季AOD最高,冬季最低。

基于一种土地利用变化新指标的土地利用变化影响因素分析——以大兴安岭林牧交错区为例

研究土地利用变化机制,是保障生态脆弱区生态环境良性发展的必然要求。基于土地利用信息图谱构建新指标——土地利用转换度,借助土地利用转移矩阵和土地利用转换度刻画1990—2021年研究区土地利用转移的宏观特征,构建渔网提取土地利用转换度,分析其空间自相关性,并用地理加权回归(GWR)分析研究区土地利用变化的影响因素,为林牧交错区社会经济发展服务。研究发现:(1)1990—2021年,研究区土地利用类型的宏观格局变化不大,林地和草地是该区域的主要用地类型,林地主要分布在东部和北部的山区,草地主要分布在西南部,耕地主要分布于山地和草原交接的地区及河谷地带。(2)1990—2021年林地呈现增加趋势,草地逐年减少,耕地和建设用地缓慢增加。(3)草地、耕地和林地是该地区土地利用变动的主要类型,以草地转出最多,主要转换为林地和耕地。(4)土地利用转换度有显著空间自相关,存在明显的高高聚集和低低聚集。转换频繁区呈倒“C”字形,分布在大兴安岭西部山区与草地过渡带,即海拔700~900 m的地带。(5)GWR分析发现坡度、气温变化、人均GDP变化是影响该区土地利用的主要因素,人均GDP增加会降低土地利用转换度,而其他因素增加会导致土地利用转换加速。(6)土地利用转换度是一种可靠的土地利用变化度量指标,能够将空间和时间融合反映土地利用状态的变化强度。

山东省大豆生产地域格局变化及影响因素分析

为给山东省大豆生产的可持续发展提供科学决策依据,本研究运用数理统计和区域比较优势测算方法,分析了山东省大豆生产地域格局的变化特征及其影响因素。结果表明:山东省大豆播种面积从1949年的191.54万hm^(2)下降到2022年的21.496万hm^(2),降幅达88.78%,自2000年以来,降幅为53.09%;大豆总产量从1949年的93.4万t下降到2022年的58.10万t,降幅为37.79%,自2000年以来,降幅为44.43%;山东省大豆单产水平明显高于全国平均水平,1978—2022年,单产增幅为163.01%,高出全国76.06%。山东大豆种植区域,由主要分布在除了滨州的沿海地市及菏泽、枣庄和临沂、济宁等地市,向鲁中地区转移,主要原因是耕地面积的减少、大豆生产的人工成本较高、净利润为负值且低于同期作物。山东省在具有生产大豆的优势背景下,也存在大豆种植收益比较低、产品竞争力弱、单产水平提高难度加大等挑战,文中最后提出了山东省发展大豆产业的对策建议。