Unsustainable Land-Based Source Pollution in a Climate of Change: A Roadblock to the Conservation and Recovery of Elkhorn Coral <i>Acropora palmata</i>(Lamarck 1816)

Chronic eutrophication and turbidity are critical detrimental factors impacting coral reef ecosystems, adversely affecting their ecological functions, services, benefits, and resilience across multiple spatial scales and over prolonged periods of time. Inadequate land use practices and lack of appropriate sewage treatment can adversely contribute to increase land-based source pollution (LBSP) impacts in coastal waters and to magnify impacts by sea surface warming trends associated to climate change. Fringing coral reefs off Vega Baja, Puerto Rico, support extensive remnant patches of Elkhorn coral Acropora palmata (Lamarck 1816), which was listed in 2006 as a threatened species under the US Endangered Species Act. Chronic impacts by LBSP have significantly affected local downstream fringing reefs. We characterized the spatial extent of a water quality stress gradient across 12 reefs along the Vega Baja coast through monthly measurements of multiple physico-chemical parameters. Most parameters, particularly PO4, , chlorophyll-a, and the concentration of optical brighteners (OABs), showed a statistically significant increase (PERMANOVA, p < 0.05) in waters close to the main pollution sources, but also in waters adjacent to Cibuco River effluents. Dissolved oxygen also declined and turbidity increased on polluted sites. PO4, , and chlorophyll-a, exceeded recommended concentrations for coral reef ecosystems by factors of 7 - 50 times, 600 - 1240 times, and 17 - 83 times, respectively, depending on the source of the effluents and the distance from sewage pollution sources. Also, water turbidity exceeded 4 - 10 times the recommended value for pristine coral reefs. Coral reefs showed significant decline in close proximity to the polluted zone, showing a significantly different benthic community structure (PERMANOVA, p < 0.0001) dominated by non-reef building taxa (i.e., macroalgae, algal turf) and bare substrate. Percent coral cover and abundance of A. palmata, showed a significant increase with distance. Coral species richness, species diversity index, and the variance in taxonomic distinctness were very low on reef patches adjacent to the polluted zone, increased at a moderate distance with increasing coral cover and co-existence of multiple species, and declined far from the pollution source due to dominance exerted by A. palmata. This study suggests that chronic LBSP resulted in a major decline of one of the largest and most dense remnant stands of A. palmata across the northeastern Caribbean and that nutrient and chlorophyll-a concentrations were unsustainable for coral reefs. This situation requires immediate solution to prevent further damage to these unprecedented resources. It further suggests that chronic LBSP may synergistically magnify sea-surface warming impacts driving corals to an increased state of risk in face of forecasted climate change impacts. Actions to mitigate and adapt to climate change impacts on coral reefs must require a priori controls of LBSP to be effective.

Guidance and Control Techniques of Carrier-Based Aircraft for Automatic Carrier Landing

We summarize the guidance and control techniques of automatic carrier landing for carrier-based aircraft.First,we analyze the carrier landing operations of the manned fixed-wing aircraft,unmanned fixed-wing aircraft and helicopters.Second,we look into the navigation and guidance system and the flight control methods for current different aircraft.Finally,we draw several conclusions of the development prospects for aircraft carrier landing,including the precision landing control techniques,precision approach and landing guidance techniques,and adaptive,reconfigurable and intelligent flight control techniques.

Spatial Distribution Assessment and Source Apportionment of Land-Based Pollutant Yield from Qingdao, China

The spatial distribution of chemical oxygen demand(COD) and total nitrogen(TN) yield from Qingdao are studied by comparing pollutant yield amount, densities and spatial aggregation(Getis-Ord indexes) among the land-based pollutant source regions(PSRs) entering the three sub-seas(i.e. the Jiaozhou Bay(JZB), other coastal area in the Yellow Sea(OCAYS) and Laizhou Bay(LZB), respectively). Industrial composition of the loads are also studied by comparing pollutant yield among the sources of agriculture, rural domesticity, industry, urban domesticity and service, and calculation of Gini coefficient. Results show that spatial distribution of COD and TN yield from Qingdao are extremely unbalanced. The JZB, with less than 3% of the total coastal sea area of Qingdao, received 62% COD load and 65% TN yield from Qingdao, while the OCAYS, with more than 97% area, only received 23% COD and 20% TN, which consist with the much worsen water quality of JZB than that of OCAYS. On the other hand, the source apportionment of COD and TN loads in the PSRs entering JZB and the OCAYS was similar. The agricultural and domestic sources with high pollution intensity account for more than 80%, while the industrial and service sources with low pollution intensity account for less than 20%. While Gini coefficients, COD 0.81 and TN 0.84 which are much higher than the ‘imbalance' threshold of 0.4, show the uneven industrial structure of Qingdao. These results may be useful in the determination of land-based pollution total amount control at the PSR level.

THE FLUX OF LAND-BASED SOURCE POLLUTANTS FROM TUMEN RIVER SYSTEM ENTERING THE SEA OF JAPAN

The influence of land based source pollutants to marine ecological environment is principally in coastal or enclosed sea waters. Flux of land based source pollutants into the sea will be effected due to social and economic development in the Tumen River basin. Pollutant type and primary pollution factor of the Tumen River in Northeast China is described by weighted coefficient method in this paper. The results indicate that the river is organic pollution type and primary pollution factor is COD. Fresh water fraction proves that the estuary is not affected by tide cycle. COD annual flux entering the Sea of Japan calculated by zero dimension model in 1993 was 90.50 ×10 3 tons. It is estimated with emission coefficient method that the COD will be 176.4 ×10 3 and 458.6 ×10 3 tons for the years of 2000 and 2010 respectively.

Optimal Preview Control for Automatic Carrier Landing System of Carrier-Based Aircraft with Air Wake

Carrier-based aircraft carrier landing is a special kind of tracking control problem and not suitable for classical control methods,which may miss the desired performance or result in overdesign.Therefore,we present an optimal preview control for automatic carrier landing system(ACLS)by using state information of system,as well as future reference information,which can avoid the shortcomings of classical control methods.Since the flight performance of carrier-based aircraft is disturbed by air wake when the aircraft flies near the area of carrier stern,we design a disturbance rejection strategy to ensure that aircraft track the glide path with high precision and robustness.Further,carrier-based aircraft is a complex nonlinear system.However,the nonlinear model of carrier-based aircraft can be linearized at equilibrium landing state and decoupled into the longitudinal model and the lateral model.Therefore,an optimal preview control system is designed.The simulation results of a carrier-based aircraft show that the optimal preview control system can effectively suppress air wake.Tracking accuracy of optimal preview controller is higher than that of the proportional integral differential(PID)control system.

Application of Case-Based Reasoning to Intelligent Support System for Coordinating Land Conflicts

To establish the institutional mechanism for land conflict coordination in China, a case-based reasomng system is developed as an intelligent support and effective manner to resolve such issues. The establishment of the case library is discussed, previous land conflict cases are archived in a structural representation format for retrieval, and the similarity algorithm is adopted to compare the case features. Group tests show a good classification performance, which reveals that the system is feasible.

论中国传统法典立法技术的发展——以唐明律计亩论罪为中心的考察

中国传统立法沿革表明,其法典立法技术在不断进步,而唐明律计亩论罪量刑方式则较为明显地反映出这种变化。其立法技术沿革模式可以分为两类:一类是侵犯他人田土使用权和所有权的犯罪,罪刑虽然有所改动、整合,但传承关系明显;另一类与土地分配、赋役征派等基本国策相关联,因政策调整,犯罪类型差异大,但其部分刑等设计却随刑罚体系传承下来。计亩论罪与计赃论罪的原理不同,不能简单视为实物计赃,其行用与犯罪不符合盗罪构成有关,也是国家财政方针在法律中的如实反映。唐明两朝计亩论罪呈现出量刑从公私不分到区分官民、刑罚偏轻且具备体系性的鲜明特点。与唐代相较,明代更加重视官有财产保护以及体系内各罪刑罚间的联系,其立法技术更趋完善。

Automatic Carrier Landing Control for Unmanned Aerial Vehicles Based on Preview Control

For carrier-based unmanned aerial vehicles(UAVs),one of the important problems is the design of an automatic carrier landing system(ACLS)that would enable the UAVs to accomplish autolanding on the aircraft carrier.However,due to the movements of the flight deck with six degree-of-freedom,the autolanding becomes sophisticated.To solve this problem,an accurate and effective ACLS is developed,which is composed of an optimal preview control based flight control system and a Kalman filter based deck motion predictor.The preview control fuses the future information of the reference glide slope to improve landing precision.The reference glide slope is normally a straight line.However,the deck motion will change the position of the ideal landing point,and tracking the ideal straight glide slope may cause landing failure.Therefore,the predictive deck motion information from the deck motion predictor is used to correct the reference glide slope,which decreases the dispersion around the desired landing point.Finally,simulations are carried out to verify the performance of the designed ACLS based on a nonlinear UAV model.

Geographic Object-Based Image Analysis of Changes in Land Cover in the Coastal Zones of the Red River Delta (Vietnam)

The majority of the population and economic activity of the northern half of Vietnam is clustered in the Red River Delta and about half of the country’s rice production takes place here. There are significant problems associated with its geographical position and the intensive exploitation of resources by an overabundant population (population density of 962 inhabitants/km2). Some thirty years after the economic liberalization and the opening of the country to international markets, agricultural land use patterns in the Red River Delta, particularly in the coastal area, have undergone many changes. Remote sensing is a particularly powerful tool in processing and providing spatial information for monitoring land use changes. The main methodological objective is to find a solution to process the many heterogeneous coastal land use parameters, so as to describe it in all its complexity, specifically by making use of the latest European satellite data (Sentinel-2). This complexity is due to local variations in ecological conditions, but also to anthropogenic factors that directly and indirectly influence land use dynamics. The methodological objective was to develop a new Geographic Object-based Image Analysis (GEOBIA) approach for mapping coastal areas using Sentinel-2 data and Landsat 8. By developing a new segmentation, accuracy measure, in this study was determined that segmentation accuracies decrease with increasing segmentation scales and that the negative impact of under-segmentation errors significantly increases at a large scale. An Estimation of Scale Parameter (ESP) tool was then used to determine the optimal segmentation parameter values. A popular machine learning algorithms (Random Forests-RFs) is used. For all classifications algorithm, an increase in overall accuracy was observed with the full synergistic combination of available data sets.

海陆过渡相页岩储层液岩作用机理及钻井液体系构建

我国海陆过渡相页岩地质储量大、资源丰度高,开发前景广阔。但钻井过程中井壁极易发生掉块、坍塌,导致井壁失稳影响钻井安全。本文通过钻井岩心观察、电镜和CT扫描、X射线衍射分析等相关实验,得到储层岩样矿物组分及微观结构等特征,结果表明:页岩气储层全岩主要含石英和黏土矿物,地层黏土矿物含量高达45.7%,且黏土矿物中不含蒙脱石,高岭石含量为35%,伊/蒙混层含量为26%;岩样表面纳微米孔隙和微裂缝发育,裂缝宽度在微米级并连通多条窄裂缝;通过岩液作用后晶层间距、表面张力、线性膨胀率和裂缝扩展变化分析,海陆过渡相页岩仅发生表面水化,揭示了海陆过渡相页岩气储层岩液作用机理。优选了水基钻井液抑制剂、封堵剂与润滑剂,构建了一套海陆过渡相页岩气储层的高性能水基钻井液体系,并对其展开了室内评价。钻井液常规性能、抑制性、封堵性、润滑性评价实验结果表明,该钻井液体系抗温100℃,高温高压失水6 mL,泥页岩膨胀率为1.03%,钻井液润滑系数整体小于0.15,体系30 min的API滤失量较基浆降低40%,可对地层微裂缝实现有效封堵,且生物毒性EC50值为37260 mg/L,属于无毒级别,能够满足海陆过渡相页岩气钻井作业施工对钻井液性能的要求并进行了现场应用,封堵防塌效果良好,可有效解决海陆过渡相泥页岩井壁失稳的技术难题。

陆基圆桶养殖大口黑鲈经济效益分析

陆基圆桶循环水养殖是一种新型高效的水产养殖模式,本研究旨在通过分析陆基圆桶循环水养殖大口黑鲈的经济效益,为促进该养殖模式的进一步推广应用提供参考。本文调查了安徽省3个县区的陆基圆桶大口黑鲈养殖企业,并对其大口黑鲈养殖的投入、产量、产值和经济效益进行分析。结果表明,投饲成本是养殖成本的第一大投入要素;通过成本与收益比较分析,投放密度、苗种来源、固定资产投入和销售时间均是影响养殖经济效益的重要因素。生产上建议养殖企业开展养殖技术研发,调整养殖模式,充分发挥陆基圆桶养殖潜力,适当延长养殖周期,提高商品鱼规格,错开销售高峰期等方式,以获得更高的经济效益。

非粮化土地流转对粮食生产土地成本的实证分析

粮食生产土地成本持续走高成为既定事实,且土地快速流转与土地成本上涨呈相同趋势。基于粮食品种层面的885个宏观数据,将土地流转分为粮食化土地流转和非粮化土地流转,实证分析非粮化土地流转对粮食生产土地成本(流转地租金和自营地折租)的影响。研究表明,非粮化土地流转显著负向影响粮食生产的土地成本、流转地租金和自营地折租,而粮食化土地流转则显著正向影响粮食生产的土地成本和流转地租金,对自营地折租的影响不显著。机制分析表明,非粮化土地流转分别提高了土地流转中采用股份合作方式的比重及土地流转中土地流入合作社的比重,从而降低了粮食生产的土地成本。因此,需适当调控两类土地流转的比重,土地流转的种植结构不能“一刀切”;同时,支持各地区通过组织创新推进股份合作方式的土地流转,并发挥好新型农业经营主体中合作社的作用。结论为有效降低粮食生产土地成本提供实证依据。

航母舰载无人机全自动着舰技术特点分析

全自动着舰技术是无人机上舰必须解决的“使能”技术。2013年,美军已完成X-47B无人机验证机在航母上的全自动着舰试验验证,为其发展MQ-25A“黄貂鱼”航母舰载无人机装备奠定了良好的技术基础。在梳理飞机着陆与着舰差异的基础上,给出航母舰载无人机全自动着舰的通用流程;从地位作用、工作范围、系统构架、系统要求、实现手段以及关键技术支撑等角度,对比有人机重点分析了航母舰载无人机全自动着舰的特点,为后续关键技术研究和武器装备建设发展提供参考。

政治沟通何以可能:土改工作队与华北根据地的基层政治

为了建立稳固的根据地,中国共产党将党的组织深入基层,以获得民众的认同支持并实现资源提取,同时治理、改造乡村,这需要进行有效的政治沟通。在战争时期,土改工作队作为中共介入地方社会的中介组织和机制设置,代表中共意志自上而下地引导甚至监督基层执行中央政策,并自下而上地反馈基层信息、帮助上层调整偏差。其在培养基层干部、动员民众、协调干群关系等方面发挥着重要功能,夯实了基层的党组织,维护了党在基层的权威。工作队的设置促进了政治信息的流动传播,形成了有效的政治沟通,有助于消除政府与民众之间的隔阂,强化民众的政治认同,由此促成中共对地方的有效治理,加强基层政权的建设和政治整合。

陆基海洋通信船舶绕射损耗模型研究

海上主要港口和航道上船舶吞吐量大,陆基船舶通信链路被过往船舶遮挡的时间长、频次高,严重影响陆基船舶通信链路的连接质量。针对船岸通信信道测量场景中发生的由过往大型船舶驶过造成遮挡而产生的阴影效应,结合高精度实测数据对这一现象的大尺度信道特性进行了分析和建模。结合阴影效应发生位置的第一菲涅尔半径、离岸距离、收发天线路径距离、天线连线高度和海面曲率引起的相对高度变化等影响因素的内在联系,解析了阴影效应发生时遮挡船只的整个运动过程,并对第一菲涅尔区与遮挡船只相对位置对应的不同时间节点进行了分类。基于ITU-R P.526-15(2019年10月)建议书中的单个刀刃形绕射模型和单个圆形绕射模型,结合船只和第一菲涅尔区的相对关系,构建了基于遮挡船的三维数据和收发端相对位置的船舶绕射损耗模型,针对实测过程中D 06(0.6倍第一菲涅尔区间隙对应的路径距离)范围内和范围外两种情况下的两次船舶遮挡过程进行了模型仿真和实测数据比对分析,并结合分析结果提出了未来的应用方向。

中国民航空中导航系统及设施综述和展望

空中导航系统是为民用航空器提供飞行引导的必要设备,是民航空管体系的重要组成部分。结合中国民航的运用实际,对空中导航系统及设施的发展及应用现状进行了系统梳理、研究和总结。结合航空器运行全过程的空中导航需求,对国内陆基导航和星基导航在民用航空领域的历史沿革、运用现状、行业分工以及当前陆基导航和星基导航领域的科研需求和研究现状进行了分析。结合北斗卫星导航系统在民用航空空中导航领域的应用,对国内空中导航技术的运用趋势和导航设施的更新策略进行了预测与展望。

基于Landsat ETM+/TM遥感影像的江门市区地表热环境分析

应用基于影像的反演算法对2001年11月20日和2005年11月23日的Landsat ETM+/TM卫星资料,反演广东省江门市区的地表温度,分析江门市区秋季地表热环境时空演变特征。结果表明:(1)空间上,江门市区秋季地表热环境具有明显差异性,呈现出较强的城市热岛效应,城区地表温度普遍高于郊区2℃以上;(2)时间上,随着城市的发展,地表高热环境区面积扩张明显,新城区呈现出更强的热环境效应;(3)不同下垫面的地表热环境状况差异显著,林地、农田、水体区热环境等级比建筑用地低1～3等级。因此,在城市规划中,适当增加城市绿地和水体面积,可改善城市地表热环境,缓和城市热岛效应。

基于水资源空间均衡的“四水四定”调控模型构建

为实现未来不同时间尺度下的水资源空间均衡与动态调控,创建了一套完整严谨、可动态调控的“四水四定”模型体系。通过模糊信息粒化窗口的支持向量机模型预测区域未来总用水量,利用基于时间序列相似性分析的自回归支持向量机模型预测区域未来分用水量,并对两类数据进行不确定性分析;构建了复杂回归函数对各类用水指标进行情景预测,经统计检验后将其作为当前用水模式下未来用水指标;构建了“四水四定”水资源承载力模型和水资源空间均衡模型,基于未来总用水量、未来各分用水量、未来用水指标,选用水资源负载系数、用水效益和水土资源匹配系数3个指标,结合基尼系数量化水资源空间均衡度,分析当前用水模式下未来水资源均衡度;构建了最优化模型,以最小化基尼系数为目标函数调整未来用水模式,实现水资源动态调控。所创建的模型体系可以实现未来不同时间尺度下的水资源空间均衡与动态调控。

资源型城市转型背景下土地利用结构的模拟与预测

[目的]资源型城市作为国家资源能源安全的重要保障城市,其转型发展方式更应向高质量方向推进。研究资源型城市转型背景下土地利用结构的变化并进行预测模拟,为新时期资源型城市国土空间优化提供新思路。[方法]基于资源型城市转型发展的概念及内涵,分析经济、社会、人口、科技、资源环境5个维度的系统性影响,并与空间布局相关联,构建系统动力学模型,以安徽省铜陵市2005—2020年的历史数据为参照,将2021—2035年的数据设置仿真情境,进行土地利用结构的多情境趋势性预测分析。[结果](1)铜陵市土地利用和经济发展现状奠定了发展的基础,可以此为依据进行转型条件设置和土地利用结构变化的合理预测。(2)资源型城市转型发展作为一个系统性概念,形成“系统—指标—要素”的层级框架,不仅相互关联,密不可分,还传导作用于不同的地类,影响土地利用系统。(3)铜陵市2021—2035年地类的情境趋势发展差异较为相似,即耕地、林地、水域、草地和未利用地的减少幅度自经济发展、社会进步、综合发展而递减,在资源保护情境下面积均有小幅度提升。建设用地则相反,增加幅度随经济发展、社会进步、综合发展而递减,在资环保护情境下扩张速度得到一定程度的控制。[结论]资源型城市的新时期转型,不仅要将内在要素融合成系统性概念,还要提升土地利用系统的关注度,重视结构合理性和发展协调性。

“陆海空天”一体化水上交通运输安全保障体系“陆基”建设应用于基层海事“最后一公里”

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