湖南省农村居民收入地区差距演变及其结构分解

农民收入是当前国内研究“三农”问题的热点之一。以湖南省为例,利用Gini系数方法,测度了1993-2008年湖南农村居民收入的地区差距变化,并通过对收入变化对区域差距变化的贡献进行分解,从收入因子的结构效应和集中效应来解释收入变化对区域差距变化的原因：工资性收入是影响农村收入差距格局的最重要因素,表现为1997-2002年间工资性收入的结构变化较快致使收入差距拉大,2002年后区域差距变大则主要是工资性收入的集中性不断增大所致;家庭经营收入在农村居民总收入中的比重下降,但仍是农村居民收入的主要来源,其对收入区域差距影响较小;财产性收入和转移性收入对收入差距格局的贡献虽然不大,但对扩大收入差异的贡献在不断增加,是未来影响农村区域差距变化的重要因素。最后提出了相关建议。     

Cities,Skills, and Inequality

ABSTRACT The surge in U.S. wage inequality over the past several decades is now commonly attributed to an increase in the returns paid to skill. Although theories differ with respect to why, specifically, this increase has come about, many agree that it is strongly tied to the increase in the relative supply of skilled (i.e., highly educated) workers in the U.S. labor market. A greater supply of skilled labor, for example, may have induced skill‐biased technological change or generated greater stratification of workers by skill across firms or jobs. Given that metropolitan areas in the U.S. have long possessed more educated populations than non‐metropolitan areas, these theories suggest that the rise in both the returns to skill and wage inequality should have been particularly pronounced in cities. Evidence from the U.S. Census over the period of 1950 to 1990 supports both implications.     

The Impact of Industrial Restructuring on Earnings Inequality: The Decline of Steel and Earnings in Pittsburgh

ABSTRACT Inter‐industry employment shifts were largely responsible for changes in the income distribution in the Pittsburgh region during the 1980s. Kernel density estimators were used, together with decomposition techniques developed by DiNardo et al. (1996 ) to show that industry shifts were responsible for over 90 percent of the earnings reductions at some points on the earnings distribution. Most of the losses at the lower end of the distribution occurred in the early 1980s as the economy plunged into a deep recession. The recovery in the later part of the decade brought little improvement as earnings in the lower part of the distribution continued to fall with the increase in employment of part‐time workers in the low‐wage trade and service sectors.     

长江中下游地区循环农业的发展

为长江中下游地区进一步开展循环农业的相关研究及制定相关政策,实现长江中下游地区循环农业的可持续发展,本研究系统阐述了长江中下游地区在我国农业发展中的重要地位及该地区循环农业具有历史悠久性、结构复杂性、模式多样性、技术先进性、功能高效性、发展可持续性等显著特征。并指出当前长江中下游地区存在着资源浪费、生态破坏、环境污染、劳力缺乏、意识淡薄、机制缺失等方面的问题,严重制约着循环农业的可持续发展。针对以上存在的问题,提出了今后在长江中下游地区推进循环农业应采取以下对策和措施：（1）提高认识;（2）制定规划;（3）完善制度;（4）增加投入;（5）培养人才;（6）扩大规模;（7）延长链条;（8）加强研发。     

The Chromatic Numbers of a Class of Circulants

There are good symmetry in the circulants.Communication network topology is largely focused because of its value of application.The chromatic numbers of the circulants C n<1,k> are completely determined.     

新生代农民工的未来认同及其影响因素研究——基于青岛的问卷

根据对青岛某纺织厂的问卷调查和深度访谈,深入分析新生代农民工未来认同的现状及其影响因素。新生代农民工目前对市民身份有所期待,但认同度不高;对未来归属地有目标,但归属感不强烈,表现出期待与徘徊并存的现状。文章从制度政策、社会环境和新生代农民工自身3个方面进行影响因素的分析,并据此提出了提升新生代农民工未来认同的对策建议：改革城乡二元体制、改善社会环境,增强关爱与沟通、调整新生代农民工的心态,提升其素质。     

On Precise Yang Le Inequality and Deficiency Sum

Along with the increase in the number of large-scale construction projects, a series of negative effects concerning various interest-related parts have emerged,which urges a comprehensive and objective evaluation of construction project so as to evaluate its overall satisfaction. In this paper,an evaluation indexes system of construction project satisfaction was advanced,which consists of 19 values coming from all main interest concerning parties, including users, investors, owners, suppliers, government and organizations nearby. A BP neural network evaluation model was built which was self-adaptive, self-organizing and self-study. And this evaluation model was applied to specific project ease. The result showed that this approach can improve the reliability and effectiveness of satisfaction evaluation of the construction project.     

未来植物育种的新目标及新技术

<正>植物驯化与改良可能是人类认识自然改造自然持续了上万年的社会活动之一。从最开始无意识的对植物的选择,到后来有意识的对植物的驯化,再到近代专业化的对植物的培育,植物选育的目标、技术和手段都在发生不断的变化和进步。20世纪60年代,被誉为绿色革命之父的Norman Borlaug博士成功地培育了抗病、耐肥、高产和适应性广的半矮杆小麦,使得小麦产量大幅提高,解除了数十亿人的饥饿危机。同样,20     

黄河下游湖泊水化学特征与水体营养类型评价

为了合理开发利用与保护黄河下游湖泊水资源,对黄河下游湖泊中的东平湖、稻屯洼、马踏湖、白云湖湖水化学成分分别进行分析,确定其水化学类型及基本特征,并对水体营养类型进行综合评价。运用与湖泊富营养化关系最为密切的chla（叶绿素）、TN、TP、CODmn和SD（透明度）作为评价参数,对照中国湖泊富营养化评价标准,并参考太湖的以百分数划分湖泊营养方法,采用单项评分和综合记分方法,确定湖水营养类型评价标准。对湖水水质监测数据分析表明：东平湖、白云湖为重碳酸类钠组Ⅱ型水、稻屯洼、马踏湖为氯化类钠组Ⅱ型水,均为偏碱性湖泊;稻屯洼与马踏湖湖水中有机物耗氧量高,平均为9.58 mg/L和21.47 mg/L,说明水体已受到污染;东平湖与白云湖湖水中有机物耗氧量不高,平均分别为5.06 mg/L与4.02 mg/L;东平湖与白云湖湖水中N:P比值较高,分别为61与45,说明东平湖与白云湖湖水中氮含量供应充分,植物、藻类的生长受到了磷的限制。对湖水营养类型评价结果表明：东平湖现属中富-富营养型水平,稻屯洼属富营养型水平,马踏湖属重富营养型水平,白云湖属中营养型水平。总体来说,黄河下游湖泊大都受到不同程度的污染,湖水水质已经恶化,水体营养类型已达富营养化水平,白云湖水质较好,需加强保护。     

中低产田杂交稻早稻“3415”肥效试验初探

采用"3415"回归最优设计开展了早稻肥效试验,研究中低产田施肥对早季杂交水稻产量的影响。结果表明:(1)氮、磷、钾不同的施肥配比对产量有极显著的影响,氮肥对产量影响最大,磷肥次之,钾肥最小。(2)氮、磷、钾肥料利用率偏低,这与土壤质地、施肥方法以及土壤原养分含量有关。(3)通过配置肥料效应模型,结合不同施肥方法的推荐施肥量和农业生产实际,确定氮、磷和钾肥推荐施用量分别为N165kg/hm²、P2O5135kg/hm²和K₂O150kg/hm²,其N∶P2O5∶K₂O=1.2∶1∶1.1。     

不同类型黄瓜苗期对亚适温弱光生理适应的差异

在单一弱光、单一亚适温及亚适温弱光下测定了不同类型黄瓜苗期的生理性状。结果表明 ,欧亚杂交品种在 3种逆境下各项生理指标均较高 ,各类型黄瓜遇单一弱光和亚适温弱光后光合速率都有一个降低又逐渐回升的过程 ,而在单一亚适温时光合速率下降不大。欧洲品种在单一弱光下叶面积、叶绿素含量高于亚洲品种 ,亚洲品种在单一亚适温时表现好于欧洲品种 ,欧洲品种可适应短期的单一亚适温。     

Revisiting Inequality and Growth: Evidence for Developing Countries

This article studies the relationship between economic growth and income inequality using panel data for a sample of Latin American countries in the period 1960–2000. Different estimation techniques and specifications are tested. Results indicate that the level of inequality has had a different effect on growth in the region, depending on the level of gross domestic product per capita. Even within a sample of developing countries, the effect of inequality on growth is negative for poorer countries, whereas for richer ones higher inequality may favour economic growth. Overall, our results are not robust to different specification techniques, and coefficients are in some cases only weakly significant, underlying the difficulties in finding a strong and robust relationship between income inequality and economic growth.     

Spatial and Temporal Metropolitan and Nonmetropolitan Trends in Income Inequality

ABSTRACT Overall total inequality for state per capita personal income as well as total inequality for nonmetropolitan and metropolitan areas are examined for the period 1969 to 1995. In each case, the total inequality was partitioned into between-and within-region variations. Statistical testing shows no perceptible differences between the major categories, nonmetropolitan and metropolitan. Further, this study uses a model to test for narrowing of income gaps within these categories. It was found that for both nonmetropolitan and metropolitan, a general trend toward equality was evidenced during the early 1970s decade. In that decade, the nonmetropolitan areas’incomes approached the metropolitan areas’incomes but showed significant divergences in the 1980s, followed again by a narrowing of the gaps in the 1990s.     

长江中下游地区小麦产量育种的方向及其策略探讨

摘要：长江中下游地区近期育成的和大面积应用的小麦品种,在目前中高产水平下（400-450kg/666.7m2）,总体以千粒重对产量的作用较大,666.7平方米穗数对产量的作用也较大,但其与环境相关值较高,每穗粒数对产量的作用似较小,但其表型相关值较大;千粒重和666.7平方米穗数对产量的影响主要由本身的直接作用所至,而每穗粒数对产量的影响似主要被通过666.7平方米穗数和通过千粒重的间接作用所分解;不同产量水平下试验品种的三因素表现为,在相对产量由低中产到较高产量时,666.7 平方米穗数增加较多,每穗粒数变化较小,千粒重提高较多,而在高产组次中,666.7平方米穗数基本稳定（或略有下降）,每穗粒数增幅较大,千粒重急剧提高。至此,作者初步认为,本地区未来高产小麦育种,虽选育穗粒重齐头并进类型,或以大穗大粒为主类型,或穗粒并重类型似均有可行性,但根据本地区小麦生态条件的特点,在策略上宜稳定穗数,增加粒数,主攻（提高）粒重。同时,还探讨了相适宜的产量构成因素。     

中国小麦育种进展与展望

近10年我国小麦育种研究在3个方面取得新进展：育成一批高产优质多抗新品种,周8425B、鲁麦14和普通小麦-簇毛麦6VS/6AL易位系在全国小麦育种中发挥了重要作用,育种技术研究也取得重要进展。但育种工作也存在4个主要问题。从育种角度评述分子标记辅助育种中连锁标记和功能标记的研究现状和存在的主要问题,并提出今后的重点领域。概括小麦品质研究中与育种密切相关的实用技术和方法,即面包、面条和饼干品质育种中的品质评价方法和选择指标,建议今后加强5个方面的工作。对未来小麦育种4个重要问题做了分析,提出国内进一步加强高产潜力研究的初步设想,建议加大持久抗性的研究力度,重视抗旱、抗热及适应性等与气候变化相关性状的研究,还分析了种业商业化等问题。     

研究和发展益生菌和益生元的前瞻

人体的结肠微生物区对健康有着极大的影响。自从引入益生菌和益生元的概念后,对人体肠微生物区组成的观点产生了极大的变化,详细研究复杂的细菌群落一直是个巨大的挑战。用抽样法研究肠微生物群将会更加成熟,并广泛应用于此项研究中。目前,以核酸为基础的分析方法是研究肠微生物区系的基本工具。应用先进的分子技术,使点查和鉴定结肠细菌的种类以及族系级别成为可能。目前正在对第二代益生元的概念展开广泛研究。了解内脏生态系统的作用机制以及处于内脏生态系统中的细菌的作用机制,对于益生菌和益生元将来的发展极为重要。