科创中国

衡水湖是华北平原具有独特自然景观的国家级湿地和鸟类自然保护区,富营养化问题是衡水湖面临的一个主要问题.通过对衡水湖水体的主要营养物质氮、磷等水质参数的影响及循环特征进行了分析,对水体的营养状况进行了评价,得出结论:衡水湖水体营养状况为富营养,但基本呈逐年减轻的趋势,并提出了富营养化治理措施.

Common compliant joints generally have limited range of motion,reduced fatigue life and high stress concentration.To overcome these shortcomings,periodically corrugated cantilever beam is applied to design compliant joints.Basic corrugated beam unit is modeled by using pseudo-rigid-body method.The trajectory and deformation behavior of periodically corrugated cantilever beam are estimated by the transformation of coordinate and superposition of the deformation of corrugated beam units.Finite element analysis(FEA)is carried out on corrugated cantilever beam to estimate the accuracy of the pseudo-rigid-body model.Results show that the kinetostatic behaviors obtained by this method,which has a relative error less than 6%,has good applicability and corrugated cantilever beam has the characteristics of a large range of motion and high mechanical strength.The corrugated cantilever beam is then applied to design a flexible rotational joint to obtain a larger angle output.The paper proposes a pseudo-rigid-body model for corrugated cantilever beam and designed a flexible rotational joint with large angle output.

Existing researches on no-moving part valves in valve-less piezoelectric pumps mainly concentrate on pipeline valves and chamber bottom valves,which leads to the complex structure and manufacturing process of pump channel and chamber bottom.Furthermore,position fixed valves with respect to the inlet and outlet also makes the adjustability and controllability of flow rate worse.In order to overcome these shortcomings,this paper puts forward a novel implantable structure of valve-less piezoelectric pump with hemisphere-segments in the pump chamber.Based on the theory of flow around bluff-body,the flow resistance on the spherical and round surface of hemisphere-segment is different when fluid flows through,and the macroscopic flow resistance differences thus formed are also different.A novel valve-less piezoelectric pump with hemisphere-segment bluff-body(HSBB)is presented and designed.HSBB is the no-moving part valve.By the method of volume and momentum comparison,the stress on the bluff-body in the pump chamber is analyzed.The essential reason of unidirectional fluid pumping is expounded,and the flow rate formula is obtained.To verify the theory,a prototype is produced.By using the prototype,experimental research on the relationship between flow rate,pressure difference,voltage,and frequency has been carried out,which proves the correctness of the above theory.This prototype has six hemisphere-segments in the chamber filled with water,and the effective diameter of the piezoelectric bimorph is 30mm.The experiment result shows that the flow rate can reach 0.50 mL/s at the frequency of 6 Hz and the voltage of 110 V.Besides,the pressure difference can reach 26.2 mm H2O at the frequency of 6 Hz and the voltage of 160 V.This research proposes a valve-less piezoelectric pump with hemisphere-segment bluff-body,and its validity and feasibility is verified through theoretical analysis and experiment.

黄骅市地处河北省东部平原,地表水资源利用能力低,浅层地下水水质差,长期依赖于开采深层地下水,造成地下水环境的破坏.通过准确把握黄骅市水资源特点,合理利用地表水,最大限度利用外来水,控制利用当地地下水,保证经济社会的可持续发展.

河北省引黄输水工程是解决河北省水资源危机的有效措施.从1993年开始的引黄输水工程,为缓解河北省水资源紧张发挥了重要作用.通过对引黄输水水质监测结果分析,通过对8次引黄输水水质评价,在对所监测的项目中.有3次输水没有超标现象,有3次污染物的超标倍数小于或等于1,有2次超标倍数在1.2~2.8之间.从输水水质主要污染物分析,主要污染物为氨氮、挥发酚、总磷、总锰、总镉.根据对黄河水源水质资料分析,氮类污染和金属类污染主要受缓和黄河水源的影响,挥发酚、总磷污染主要受河道环境的污染.通过对引黄调水水质评价,受黄河水源和沿途河道的影响,引黄调水水质存在较大的不确定性.因此应加强对引黄调水水质的监测,为用水部门及时提供调水水质信息,以便制宰相席的用水方案.

水平衡测试是加强用水科学管理,最大限度地节约用水与合理用水的一项基础工作.解释了水平衡测试的定义及开展测试工作的依据,分析了水平衡测试参数之间关系,介绍了水平衡测试的方法,结合承德市中心医院水平衡测试实例,分析其用水现状,为制定用水定额和计划用水量指标,提供了较准确的基础数据,为今后节约用水提出了合理化的建议.

日本高度重视水源地保护及水生态修复,在水资源管理体制、法律法规体系建设、水资源开发利用、水源地保护、水生态修复、水污染事故应急处理、水科学研究治理、宣贯教育及公众参与等多个方面取得了先进经验和良好的效果.提出了从日本积极推行的水资源"五保体系",即"社会保水、政策机制保水、科技保水、工程保水、管理保水"中得到借鉴,加强我国在"保水教育、立法保护、污水治理、生态建设、政府主导、全民参与"等方面进行水源地保护及水生态修复工作的建议.

故城县是严重的资源型缺水地区,没有可用的地表水资源,地下水资源含氟量超标,农村居民生活用水存在不安全因素.针对故城县水资源及供水现状,分析了农村饮水安全存在的问题、影响因素及分布特征,提出只有通过引黄、南水北调等外流域调水,才是解决当地饮水安全的最佳途径.

石家庄市水资源严重短缺,地表水量减少、地下水超采严重、水环境恶化.针对石家庄市水资源现状及存在问题,分析造成水资源紧缺的原因,提出缓解石家庄市水资源短缺状况,实现石家庄市国民经济的可持续发展,必须坚持建立节水型社会、多方开源、加强水资源管理,特别是要加快南水北调工程的建设.

近些年来,我国中小城市快速发展,城乡建设水平不断提高,水资源供需矛盾日益突出,由于水资源配置工程体系不完备,水环境污染仍然严重.从环境治理、水利建设和生态保持等综合角度,寻求切实可行的中小城市水环境建设与管理方法,具有重要的理论及现实意义.