检索结果-南通市图书馆

Highly degradable chitosan-montmorillonite (MMT) nanocomposite hydrogel for controlled fertilizer release

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2023年第5期17卷 1-11页

作者： Zeou Dou Maria Vitoria Bini Farias Wensi Chen dongjing He Yuhang Hu Xing Xie School of Civil and Environmental Engineering Georgia Institute of TechnologyAtlantaGA 30332USA George W.Woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlantaGA 30332USA School of Chemical and Biomolecular Engineering Georgia Institute of TechnologyAtlantaGA 30332USA

Fertilizer consumption is increasing drastically along with the rapid expansion of farming in response to the ever-growing population. However, a significant portion of the nutrients in traditional fertilizers is lost during leaching and runoff causing economic loss and environmental threats. Polymer-modified controlled-release fertilizers provide an opportunity for mitigating adverse environmental effects and increasing the profitability of crop production. Here, we present a cheap and easy-to-fabricate controlled-release fertilizer excipient based on hydrogels scaffolded by safe and biodegradable chitosan and montmorillonite (MMT) nanoclays. By introducing elastic and flexible physical crosslinking induced by 2-dimensional (2D) MMT nanoflakes into the chitosan hydrogel, highly swellable and degradable chitosan-MMT nanocomposites were fabricated. The addition of MMT into the chitosan hydrogels enhanced the total release of phosphorous (P) and potassium (K), from 22.0 % to 94.9 % and 9.6% to 31.4 %, respectively, compared to the pure chitosan gel. The chitosan-MMT nanocomposite hydrogel achieved a well-controlled overall fertilizer release in soil. A total of 55.3 % of loaded fertilizer was released over 15 d with a daily release of 2.8 %. For the traditional fertilizer podwer, 89.2 % of the fertilizer was washed out during the first irrigation under the same setup. In the meantime, the nanocomposites improved the water retention of the soil, thanks to its excellent water absorbency. Moreover, the chitosan-MMT nanocomposite hydrogels exhibited high degradation of 57 % after swelling in water for 20 d. Such highly degradable fertilizer excipient poses minimal threat to the long-term fertility of the soil. The engineered Chitosan-MMT biopolymer scaffold as a controlled-release fertilizer excipient provides a promising opportunity for advancing sustainable agriculture.

关键词： Biopolymer Hydrogel Controlled-release fertilizer Nanoclay Nanocomposite

医院院长分包责任制科室医护质控小组活动效果

在线全文

学校读者我要写书评

暂无评论

护理研究 2024年第12期38卷 2254-2256页

作者：魏玉如李冬静李艳丽王素玲刘倩孙腊香张福娟董景珍田悦孙艳乔王艳芬杨茜唐山市丰南区医院河北063300

目的:探讨医院院长分包责任制科室医护质控小组活动效果。方法:选取河北省唐山市某二级甲等医院所有实施质控小组活动的临床、医技科室共30个,推行院长分包科室并带领职能部门参加科室医护质控小组活动分析会议。分别于实施3个月、6个月... 详细信息

目的:探讨医院院长分包责任制科室医护质控小组活动效果。方法:选取河北省唐山市某二级甲等医院所有实施质控小组活动的临床、医技科室共30个,推行院长分包科室并带领职能部门参加科室医护质控小组活动分析会议。分别于实施3个月、6个月、9个月后比较质控效果及不良事件上报情况。结果:实施院长分包责任制3个月后活动效果良好及以上占40%,6个月后活动效果良好及以上占70%,9个月后活动效果良好及以上占97%。9个月后不良事件上报意识显著增强,上报隐患事件占62.96%,其中护理隐患事件占隐患事件的63.39%。结论:医院院长分包责任制参与科室医护质控小组活动分析效果满意,促进了医院医疗服务能力和质量管理的科学化,各科室主动上报不良事件意识增强,保证了医疗质量和病人安全。

关键词：院长分包责任制护理质量质控不良事件护理管理

新中国成立以来基本经济制度形成发展的理论逻辑与实践逻辑

在线全文

学校读者我要写书评

暂无评论

管理世界 2022年第3期38卷 1-8,18页

作者：王东京第十三届全国人大财政经济委员会

新中国成立后亟待建立自己独立完整的工业体系,推进工业化需采用"国家所有制"和"集体所有制";而要调动一切积极因素参与社会主义现代化建设,必须调整生产关系,坚持公有制为主体、多种所有制经济共同发展。在国家实现工业化初期阶段,迅... 详细信息

新中国成立后亟待建立自己独立完整的工业体系,推进工业化需采用"国家所有制"和"集体所有制";而要调动一切积极因素参与社会主义现代化建设,必须调整生产关系,坚持公有制为主体、多种所有制经济共同发展。在国家实现工业化初期阶段,迅速推进工业化需采用计划经济体制,事实证明,计划经济体制为中国经济起飞奠定了雄厚的物质基础;而进入工业化中后期阶段,需调整产业结构,而调整产业结构必须让市场起决定作用和更好发挥政府作用。消费资料的任何一种分配,都是生产条件本身分配的结果:单一公有制与计划经济体制决定了单一的按劳分配制度;而以公有制为主体、多种所有制经济共同发展与市场经济体制,则决定应以按劳分配为主体、多种生产要素共同参与分配。

关键词：基本经济制度所有制经济体制分配制度

Highly efficient generation of arbitrary vector beams with tunable polarization, phase, and amplitude

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2018年第4期6卷 228-233页

作者： SHENG LIU SHUXIA QI YI ZHANG PENG LI dongjing WU LEI RAN JIANLIN ZHAO MOE Key Laboratory of Material Physics and Chemistry under Extraordinary Conditions and Shaanxi Key Laboratory of Optical Information Technology School of Science Northwestern Polytechnical University Xi'an 710129 China

We propose an efficient and robust method to generate tunable vector beams by employing a single phasetype spatial light modulator(SLM). With this method, a linearly polarized Gaussian beam can be converted into a vector beam with arbitrarily controllable polarization state, phase, and amplitude. The energy loss during the conversion is greatly reduced and depends mainly on the reflectivity of the SLM. We experimentally demonstrate that conversion efficiency of about 47% is achieved by using an SLM with reflectivity of 62%.Several typical vector beams, including cylindrical vector beams, vector beams on higher order Poincaré spheres,and arbitrary vector beams attached with phases and with tunable amplitude, are generated and verified experimentally. This method is also expected to create high-power vector beams and play important roles in optical fabrication and light trapping.

关键词：空间光调制器光束通讯技术发展现状

Water inrush evaluation of coal seam floor by integrating the water inrush coefficient and the information of water abundance

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2014年第5期24卷 677-681页

作者： Shi Longqing Qiu Mei Wei Wenxue Xu dongjing Han Jin Shandong Provincial Key Laboratory of Depositional Mineralization & Sedimentary Minerals College of Earth Science and Engineering Shandong University of Science and Technology College of Information Science and Engineering Shandong University of Science and Technology

The method of singular coefficient of water inrush to achieve safety mining has limitation and one sidedness. Aiming at the problem above, large amounts of data about water inrush were collected. Then the data, including the maximum water inrush, water inrush coefficient and water abundance in aquifers of working face, were processed by the statistical analysis. The analysis results indicate that both water inrush coefficient and water abundance in aquifers should be taken into consideration when evaluating the danger of water inrush from coal seam floor. The prediction model of safe-mining evaluation grade was built by using the support vector machine, and the result shows that this model has high classification accuracy. A feasible classification system of water-inrush safety evaluation can be got by using the data visualization method which makes the implicit support vector machine models explicit.

关键词：煤层底板评价等级系数和突水支持向量机信息整合预测模型

The Relationship Between Fat Content and Biological Parameters of Bigeye Tuna(Thunnus obseus) in the Western Central Indian Ocean

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2016年第5期15卷 853-860页

作者： SONG Liming SHEN Zhibin LI Jie LI dongjing LI Yuwei College of Marine Sciences Shanghai Ocean University Shanghai 201306 P. R. China National Engineering Research Center for Oceanic Fisheries Shanghai Ocean University Shanghai 201306 P. R. China The Key Laboratory of Sustainable Exploitation of Oceanic Fisheries Resources Ministry of Education Shanghai Ocean University Shanghai 201306 P. R. China Collaboration Innovation Center for National Distant-Water Fisheries Shanghai 201306 P. R. China

Comparing fat content with physiological status can throw light on the reproduction and feeding behavior of the fish. The biological data of 586 bigeye tuna were collected from the longline fishery in the waters of Western Central Indian Ocean from November, 2012 to March, 2013. The spatial or temporal distribution of the fat content, and the relationships of fat content with gender, round weight, gonadal maturity and fork length were analyzed. A generalized additive model(GAM) was used to analyze the relationships between fat content and fork length(FL), gonadosomatic index(GSI), condition factor(K), and somatic index(SI). Results showed that: 1) the fat content of bigeye tuna was in the range of 3.1%–27.1% with the average 12.8%; 2) there were no significant geographical differences of average fat content(P > 0.05) among 1? squares in general; 3) there were no significant differences(P > 0.05) of the fat content for different genders, months, or gonad maturity stages; 4) there was an extremely significant correlation(P = 0.000) between fat content and FL and GSI. There was no significant correlation(P = 0.051) between fat content and K. There was a significant correlation(P = 0.003) between fat content and SI. The results of this study suggest that the fat content of the matured fish was relatively stable. The survey area was in a spawning region, and the survey period was the spawning season for bigeye tuna.

关键词： Thunnus obseus fat content biological parameters Western Central Indian Ocean

在线全文

学校读者我要写书评

暂无评论

全站仪测尺频率测量与温度影响研究

计量科学与技术 2024年第5期68卷 37-43页

作者：刘洋李连福王德利蒋远林李建双刘晓东缪东晶赫明钊中国计量科学研究院北京100029 中国计量大学杭州310018

全站仪是集成测距、测角和坐标测量的高精度测量仪器,在基础设施建造和大地测量等领域均具有广泛且重要的应用。其中,测尺频率的变化是全站仪测距乘常数的主要来源,是关联仪器测距特性的基本参量,能够从本质上表征测量仪器的测距乘常数... 详细信息

全站仪是集成测距、测角和坐标测量的高精度测量仪器,在基础设施建造和大地测量等领域均具有广泛且重要的应用。其中,测尺频率的变化是全站仪测距乘常数的主要来源,是关联仪器测距特性的基本参量,能够从本质上表征测量仪器的测距乘常数水平。通过研制全站仪测尺频率的自动测量系统,利用能够参考至高精度频率标准的测量技术实现对全站仪测尺频率的实时动态测量。同时,基于研制的全站仪测尺频率自动测量系统,通过控制环境温度的方式,对全站仪测尺频率的温度特性进行了深入研究。对进一步评价全站仪测距性能,明确全站仪检定校准过程中测距乘常数来源具有重要意义。

关键词：计量学全站仪测尺频率测距乘常数温度影响

东北地区装备制造业高端化发展水平及效应评价研究

在线全文

学校读者我要写书评

暂无评论

工业技术经济 2023年第4期42卷 34-42页

作者：黄东晶黑龙江科技大学管理学院哈尔滨150027

东北地区有必要大力推进装备制造业的发展,充分利用实体经济的基础性作用,实现东北地区的可持续发展。本文分析东北地区的经济发展是否会受到装备制造业高端化发展的正向影响,同时,从横向和纵向两个维度评价东北地区装备制造业高端化发... 详细信息

东北地区有必要大力推进装备制造业的发展,充分利用实体经济的基础性作用,实现东北地区的可持续发展。本文分析东北地区的经济发展是否会受到装备制造业高端化发展的正向影响,同时,从横向和纵向两个维度评价东北地区装备制造业高端化发展水平,与同类研究相比具有一定的创新性。研究结果表明:(1)东北地区的经济水平与装备制造业高端化发展存在互相促进的关系;(2)东北地区装备制造业高端化发展水平总体偏低,同时有逐渐稳定上升的态势。因此,应从装备制造业创新能力、产业集聚、智能化发展、可持续性等方面入手,着力推进东北地区装备制造业高端化发展。

关键词：东北地区装备制造业高端化效应分析自向量回归模型熵权法

在线全文

学校读者我要写书评

暂无评论

一株西藏牦牛源格氏乳球菌的分离鉴定

西藏农业科技 2024年第1期46卷 40-43页

作者：苏中华王冬经陈建春央珍益西旺扎格桑卓玛宁立宏曾江勇西藏自治区动物疫病预防控制中心西藏拉萨850000 西藏自治区农牧科学院畜牧兽医研究所西藏拉萨850009 西藏昌都帽卡若区畜牧站西藏昌都854000 西藏山南市浪卡子县伦布学乡农牧综合服务中心西藏山南851100

为了弄清引起西藏牦牛乳腺炎的病原,采集患有乳腺炎的牦牛乳汁样品进行细菌培养,将分离到的1株细菌命名为XZ-1并进行染色镜检和16S rRNA基因扩增、比对,从GenBank上下载相似性最高细菌的16S rRNA基因,采用DNA Star软件进行同源性和遗传... 详细信息

为了弄清引起西藏牦牛乳腺炎的病原,采集患有乳腺炎的牦牛乳汁样品进行细菌培养,将分离到的1株细菌命名为XZ-1并进行染色镜检和16S rRNA基因扩增、比对,从GenBank上下载相似性最高细菌的16S rRNA基因,采用DNA Star软件进行同源性和遗传进化分析。结果显示,分离株细菌革兰氏染色,镜检为阳性,散在或成双或短链排列的球状菌;16S rRNA基因比对表明,与GenBank中格氏乳球菌的相似性达到99.43%~99.93%,与格氏乳球菌参考株的同源性为99.5%~100%;遗传进化分析表明,西藏分离株XZ-1与格氏乳球菌参考株形成一个大的分支,且与格氏乳球菌SCH和MS4-2参考株亲缘关系较近,聚为一簇。研究表明,该分离株为格氏乳球菌,是引起乳腺炎的病原之一,为今后开展牦牛乳腺炎病原及格氏乳球菌的研究提供参考依据。

关键词：西藏牦牛格氏乳球菌分离鉴定