宁夏农业科技资源配置模式研究

分析了宁夏农业科技现状,指出创新和支撑能力明显提升,科技对农业增长的贡献率达到52％.然而在宁夏农业科技取得快速发展的同时,全区农业科技总体水平还较低,科技支撑和引领作用发挥的不够,与现阶段农业发展对科技的要求相比还有较大差距.在全面分析宁夏农业科技资源现状基础上,总结了现有农业科技资源配置模式,提出了科技资源配置中存在的问题及优化的建议.     

城市产业结构优化与土地资源配置研究——以广州市为例

产业结构的调整与优化升级是当前我国城市经济发展过程中面临的重大问题。城市土地资源的合理利用对于城市可持续发展与经济效益、社会效益和环境效益的提高至关重要。根据产业结构演化理论和区位与租值理论,分析了广州市的产业结构现状与城市土地利用结构存在的问题,探讨了城市产业结构优化与土地资源配置之间的相互关系,并就广州市的产业结构优化和城市土地资源合理配置等问题提出了建议。     

梅州市产业结构优化与土地资源配置研究

产业结构的调整与优化升级是当前我国经济发展过程中面临的重大问题。分析了地处粤东山区的梅州市的产业结构现状,并就1997~2006年间的产业结构进行了灰色关联分析,提出了全市产业结构优化与土地资源优化配置的措施,即以结构调整为主线,推动产业结构优化升级、加强土地整理、加快土地置换、发挥市场对资源配置作用的同时,加强政府的宏观调控、积极推进"双优化"工程。     

Relative growth and photosynthetic response of water-seeded rice and Echinochloa oryzoides (Ard.) Fritsch to shade

Echinochloa oryzoides is a serious weed of rice worldwide and one of the most important weeds of water-seeded rice in California, USA, where resistance to most available herbicides has been detected. Developing new integrated weed management strategies that include rice suppression of E. oryzoides growth requires understanding their relative responses to resource limitation. The effects of shade on the growth, morphology and CO 2 exchange rates (CER) of E. oryzoides and rice (cv. M-202) were assessed in glasshouse and growth chamber experiments. Plants were grown at 100, 50 or 18% of full sunlight (glasshouse) or at 500 and 250 µmol PPFD m-2s-1 (growth chamber) within a completely randomized design with two factors and four replicates. Shade was imposed at 21 days after seeding (d.a.s.) (glasshouse) and at 14 d.a.s. (growth chamber). Height, leaf area, tillers, and leaf, stem, root and seed dry weights were determined for both species. CER were determined for plants in the growth chamber. Both species increased dry-matter allocation to leaves and maintained CER when subjected to low light. However, in contrast to rice, E. oryzoides maintained or increased leaf area, specific leaf area and leaf area ratio (LAR) in response to shade. E. oryzoides tiller number and seed output were reduced only at 18% sunlight. Rice lacked such adaptive ability and tiller number and seed were reduced at 50% sunlight. Shade alone may not prevent the seed production of E. oryzoides. However, E. oryzoides increased LAR at the expense of allocation to roots. Thus, for substantial E. oryzoides control, early nutrient deprivation by rice roots may be as relevant as improving rice ability to intercept light.     

GAMS在灌区水资源优化分配中的应用

水资源的短缺是全球性问题,水资源优化分配是重要的农业节水措施,是目前农业节水研究的重大课题之一。当水资源优化分配中未知量较多时,传统的手工计算方法已不能满足需要,必须用计算机模型来计算。GAMS是国外应用较广的计算机语言,能通过很简单的计算程序迅速求解线性规划、非线性规划、整数规划问题。通过GAMS语言,建立了简单的灌区水资源分配模型,求解了不同水库泄水条件下的各用户最优水量分配方式。     

生产性服务业与资源配置优化促进工业园区转型升级研究

企业选择进入工业园区的根本原因在于能获得园区外企业所不具备的资源配置优势。工业园区生产性服务业发展促进了园区企业的外部资源获取，能够监测园区企业所获取的资源质量，并保证园区企业从外部获取资源的长效性。我国工业园区应着力完善生产性服务业和制造业互动模式，政府应创造良好的园区硬环境和软环境。