实施专业技术承包推动山区茶产业发展实践

山区农村劳力老龄化、馈乏,分散型茶园的标准化管理、稳产、提品、降农残等是突出矛盾。解决这些矛盾,确保质量安全,须从源头找路径。根据山区茶产业生产实际,2018年至2021年连续三年对恩施市芭蕉乡境内分散型茶园实行全程专业化技术承包,效果显著。1基本情况2018年5月1日至2021年6月20日,恩施深耕农业科技有限公司对恩施市芭蕉乡7个村2000余亩茶园进行技术承包,由恩施深耕农业科技有限公司与茶专业合作社按每667m^(2)700元签定承包技术合同,连续实施三年。合同执行期间,由州、市农业农村局的相关技术部门、芭蕉乡政府及乡农业服务中心、所在村民委员会等监督实施并组织验收,对承包效果进行跟踪观察。

Investigation on Magnetic Properties of Exchange Coupled Transition Metal Complexes Ⅱ．Theoretical Model for Trinuclear Complexes

Theories based on the isotropic Heisenberg model have been adjusted to the study of magnetic properties in exchange coupled unsymmetrical trinuclear complexes.Program for theoretical fitting of the variable-temperature magnetic susceptibility has been set up to produce coupling constants and spin states of the magnetic centers.Calculation has been carried out on a series of Co(Ⅱ)complexes containing mixed thiolato and phosphine ligands:Co3(mp)2(mpH)2(PR3)3(R=Et,R=Bu) and Co3(bdt)3 (PBu3)3.It has been found that all these studied complexes are anti-ferromagnetically coupled.Coupling constant shows the strength of the exchange interaction,which is determined by many factors.Relation between the spin state and the coordination circumstance of Co(Ⅱ) was discussed too.