Effect of Different Soil Regulation Measures on Yield and Soil Fertility of Eucalyptus Plantation in Southern Guangxi

In view of the problems of decreased unit yield,soil acidification,decreased soil organic matter and soil fertility caused by high generation single pure Eucalyptus plantation in southern Guangxi,a field experiment was conducted to study the yield,soil organic matter and soil fertility under six soil conditioning measures[interplanting Tephrosia candida under the forest,interplanting Sesbania cannabina under the forest,organic fertilizer application,residue to woodland,soil testing and formulated fertilization,and applying pure chemical fertilizer(CK)],and the enhancing effects of each treatment on the yield and soil improvement of Eucalyptus plantations were further comprehensively evaluated.The results showed that compared with the control,the five treatments could increase the average stock of Eucalyptus,among which the average stock under the treatment of interplanting T.candida under the forest was the highest,followed by soil testing and formulated fertilization.The soil organic matter content and soil fertility of the forest were significantly improved by interplanting green manure,organic fertilizer application and soil testing and formulated fertilization models,while the short-term(1 a)effect of the residue treatment on the improvement of soil organic matter and soil fertility was insignificant.During the actual production process,interplanting green manure and residue treatment were not effective due to the inoperability,and the applicability were not wide,which still needed further study.Therefore,organic manure application and soil testing and formulated fertilization were suitable choices to promote the improvement of productivity and soil quality of Eucalyptus plantation in Guangxi.

Pre-evaluation on stability of proposed expressway embankment with existing geothermal regulation measures in permafrost regions

Embankment stability is the primary problem for the expressway construction in permafrost regions.The proposed Qinghai-Tibet Expressway(QTE)is planned to construct along the Qinghai-Tibet Project Corridor.Confronted with harsh environmental condition and intense heat exchange between earth and atmosphere,it is necessary to predict and evaluate the stability of the proposed QTE.In this study,the factors affecting the embankment stability are analyzed firstly.And then,a scheme for the stability evaluation of the embankment is established.Finally,the evaluation scheme is used for the pre-evaluation of the stability for the proposed QTE with different geothermal regulation measures(GRMs).The results indicate that the influencing factors include climatic environment,permafrost property,engineering condition and geological condition,and among them,engineering condition and permafrost property are the main influence factors for embankment stability.The stability of the proposed QTE varies greatly in the different geomorphological regions.The application effect and contribution to embankment stability of the existing GRMs are different,and using GRMs cannot completely overcome the influence of various factors on expressway stability.In the construction process,different GRMs should be adopted depending on the geomorphological environment where the embankment is located to ensure the embankment stability.

Ecological Effects Measures and Regulation of Tourism Island

With the sustainable development of tourism in China, the phenomenon of ecological islanding in tourist attractions gradually becomes prominent, affecting the sustainable development of landscape and ecological environment in scenic spots. Tourist attractions are influenced by spatial location, resource characteristics and ecology, environmental protection and other factors. The appeals of government, tourism enterprises, developers and community villagers in the aspect of landscape and ecology are different in the development process of tourism, leading to different degrees, frequencies and scopes of tourism ecological islanding with prominent conflicts. This is a typical problem in the development stage of tourist attractions in China. Taking six scenic spots in Puzhehei as examples, the values of tourism ecological islanding were measured scientifically, and a anti-planning regulatory mechanism against tourism ecological islanding was established in this paper to achieve the sustainable development of the tourist attractions and ecological environment.

National Verification Regulations and Calibration Specifications of Measuring Instruments of P.R.China in 2010(2010 No.131)

General Administration of Quality Supervision,Inspection and Quarantine of P.R.China has approved the following 8 national measuring verification regulations in 2010 and publicize now.

National Verification Regulations and Calibration Specifications of Measuring Instruments of P.R.China in 2008

General Administration of Quality Supervision,Inspection and Quarantine of P.R.China hasapproved the following 24 national measuring verification regulations in 2008 and publicize now.

National Verification Regulations and Calibration Specifications of Measuring Instruments of P.R.China in 2008 2008 NO.35

General Administration of Quality Supervision,Inspection and Quarantine of P.R.China has approved the following 11 national measuring verification regulations in 2008 and publicize now.

National Verification Regulations and Calibration Specifications of Measuring Instruments of P.R.China in 2008 2008 No.22

General Administration of Quality Supervision,Inspection and Quarantine of P.R.China has approved the following 10 national measuring verification regulations in 2008 and publicize now.

Exploration on ecological regulation of the reservoirs

Reservoir regulation process in the Yangtze River basin is mainly divided into two types of flood regulation and initiating benefit regulation. The present reservoir management system and operation mode are mainly for dealing with or coordinating of flood control and benefit initiation as well as benefit distribution among various beneficial functions. From the view point of river ecosystem protection, the current regulation mode has two kinds of problems: firstly, most of the reservoir regulation plans do not consider ecosystem protection at downstream of dams and needs of environment protection in reservoir areas; secondly, integrated regulation or management of water resources is ignored. It is very necessary to improve reservoir regulation mode, bearing problems faced by regulation of the Three Gorges reservoir and issues related to cascade development and regulation in Tuojiang and Minjiang River basins in mind. In accordance with the concept of scientific development, and the philosophy of "ensuring a healthy Yangtze River and promoting the harmony between human and water", taking flood control, benefit initiation and eco-system as a whole, this paper put forward the basic consideration to improve reservoir regulation as follows: on the basis of requirements of ecosystem protection at downstream of dams and needs of environment protection in reservoir areas, we should bring the functions of reservoir such as flood control and benefit initiation into full play, control the negative influence to the ecosystem at downstream of dams and the environment in reservoir areas in an endurable scope, and restore the ecosystem and the environment step by step. This paper put forward the relevant regulation process aiming at the idiographic problems such as protection of ecosystem at downstream of dams and environment in reservoir areas, protection of aquatic wildlife species and fish species, regulation of sediment and protection of wetland.

供需视角下雨洪调节关键区识别及规划策略研究

雨洪调节服务供需测度对识别易涝区域、合理配置自然资源、优化雨洪安全格局具有重要意义。目前的研究多从供给或需求单一角度聚焦中心城区雨洪调节能力,而全域尺度雨洪调节服务供需测度实证研究较少,雨洪调节服务供需空间分布特征和影响供需平衡的关键驱动因子有待探究。以湖北省通城县为例,通过SCS-CN模型量化县域生态空间雨洪调节服务供给能力,利用洪水脆弱性指数评估社会经济对雨洪调节服务的需求水平,进而识别县域雨洪调节服务供需空间分布特征及失衡关键区域;结合斯皮尔曼相关系数分析和冗余分析,探究影响供需失衡的关键因子,并考虑人口密度和建设用地面积对雨洪调节服务供需的影响,从“宏观-中观-微观”3个尺度构建雨洪安全格局。研究结果表明:①县域内雨洪调节服务供需空间存在显著的分异情况,因此需要从整体角度构建和优化雨洪安全格局;②中心建成区是雨洪调节服务供需失衡最严重的区域,需要采取雨洪安全管控和修复措施;③县域内雨洪调节服务供需失衡的关键影响因子是人口密度,与雨洪灾害风险等级呈负相关。研究成果可为识别雨洪调节服务供需失衡区域以及优化国土空间规划体系下多尺度雨洪安全格局提供量化支持和依据。

热应激对肉鸡的生理危害与缓解措施

环境温度超过动物机体等热区中的舒适温度上限后会产生热应激现象。肉鸡体毛丰厚、生长速度较快、无汗腺,受饲养密度的影响,在高温环境下易出现热应激现象。热应激容易造成肉鸡采食量减少、生长速度减缓,降低肉鸡免疫防御功能,抑制免疫器官的生长发育,增加组织炎性细胞因子表达。热应激能够降低肠道绒毛高度,增加隐窝深度,使肠道结构受损,肠道微生物菌群的数量发生改变。热应激轻则导致肉鸡生理功能紊乱,严重时会导致肉鸡死亡,造成经济损失。文章总结了热应激对肉鸡生产性能、免疫性能、肠道形态和肠道屏障方面的影响以及预防和缓解热应激的措施,为生产实践中预防和缓解热应激提供参考。

感潮河段江滩湿地水体交换模拟与调控措施研究

保障湿地水体交换能力对完善湿地功能,维持湿地生态系统的健康至关重要。南京绿水湾湿地是长江江滩湿地,具备多种湿地特点,动力条件复杂。以绿水湾湿地为研究对象,通过构建二维水动力―水龄耦合数学模型,模拟了现状和不同闸、泵调控措施下各区域的水动力特征及水体交换能力。结果表明:现状工况湿地内部水面覆盖率低,水体交换能力差,大部分区域水体交换时间在7 d以上,甚至是14 d以上;建闸后虽然增加了枯季的水面覆盖率,但明显减弱了湿地内水动力,延长了各区域换水周期,换水周期大于14 d的区域明显增多;补水泵站的运用整体上缩短了大部分区域的换水周期,使得水域流速大于0.010 m/s的区域面积明显增加,换水周期大于14 d的区域面积减少。建闸蓄水后,为预防藻类暴发,需控制湿地内水体的换水周期在14 d内,结合各区域水动力和水体交换特点,提出了闸门生态调度、布置净水能力较强的挺水或沉水植物、增设补水点等调度策略。

数字经济促进城市绿色发展的碳排放效应与影响因素研究

本文基于2010~2021年我国284个地级市面板数据,采用超效率SBM模型等方法,研究数字经济对城市绿色发展的碳排放效率及其影响机制。研究结果显示,数字经济发展有助于提升城市的碳排放效率。其中,财政支出绩效和环境规制强度起到中介作用;数字经济在经济发展速度和人力资本水平的调节下,更显著地促进城市的碳排放效率;同时,数字经济对城市碳排放效率的影响存在明显的异质性。因此,本文提出了加强数字经济发展与碳排放效率协同增长、优化政府财政支出、加快数字城市建设等建议。

水稻花粉管生长及其对非生物逆境胁迫的响应机理研究进展

水稻是我国乃至全世界最为重要的粮食作物之一。全球气候变暖背景下,高温、干旱、低温寡照等极端天气频繁发生,水稻产量品质形成受到不同程度的影响,严重威胁我国的粮食安全。花粉管在雌蕊组织中的生长是水稻生殖生长最为关键的过程,高温等非生物逆境胁迫可严重干扰花粉管生长的信号传递和能量代谢,进而导致水稻受孕失败。因此,研究高温等逆境胁迫影响水稻花粉管生长及其调控机制具有重要意义。本文综述了水稻花粉管生长的基本过程,包括信号传递以及能量代谢,同时阐述了高温、干旱、低温寡照、重金属等逆境影响花粉管生长致使小穗败育的作用机制及其栽培调控技术,为减缓高温等逆境胁迫干扰水稻花粉管生长,提高水稻授粉受孕能力的栽培技术提供理论参考,并对今后的研究方向进行展望。

面向数字孪生的飞机装配测量与调控

飞机装配所涉及的内容和技术十分复杂,应用数字孪生技术可使制造人员清楚地掌握飞机装配过程中和装配后的状态,多源数字化测量技术是建立数字孪生体和实现数字孪生的基础,通过补偿、协调、调整等调控手段,可使飞机装配整个过程的几何量、力学量处于合理范围,从而保证飞机装配质量。在分析相关技术国内外应用状况的基础上,给出了基于数字孪生的飞机装配测量与调控技术的实现途径。

豆类蛋白聚集机制及调控措施研究进展

目前在食品加工、化学工业生产以及生物医药等领域普遍存在蛋白质聚集的现象。近年来,豆类蛋白生产规模不断扩大,其营养价值及经济效价优势显著。基于此,越来越多的学者对豆类蛋白聚集、解聚行为进行了深入探讨。但豆类蛋白在食品加工过程中会产生一些聚集行为,这是不可避免的现象。随着加工食品的手段越来越多样化,豆类蛋白的聚集行为对食品品质、口感、风味的影响也逐渐引起人们的重视。文章介绍了豆类蛋白聚集行为的产生机理,系统详尽地综述了调控豆类蛋白聚集行为的措施及对豆类蛋白聚集行为进行表征的方法。相信豆类蛋白在未来可以成为更好的蛋白质补充方式,有更加广泛的发展和应用空间,并希望为研究豆类蛋白聚集行为提供更多的理论支持。

穿心莲内酯生物合成与调控的研究进展

穿心莲内酯是中药材穿心莲的主要活性成分,具有清热解毒、抗菌消炎、保肝利胆等功效,临床上主要用于治疗小儿肺炎和上呼吸道感染等疾病。近年来,由于环境因素长期影响、品种纯度不高以及优良品种选育工作滞后等原因,很大程度上限制了穿心莲的品质提升。在穿心莲药材质量评价中,穿心莲内酯的含量是一项非常重要的指标,通过解析穿心莲内酯生物合成的分子机制及积累规律,有助于提升穿心莲药材质量。该文综述了穿心莲内酯的生物合成途径与分子调控机制,穿心莲内酯的生物合成主要分为两大阶段,即穿心莲内酯前体的合成阶段和穿心莲内酯合成的修饰阶段,其中前体合成研究已经较为清楚,但有关穿心莲内酯合成修饰阶段的途径和关键酶的挖掘还处于空白水平,需进一步研究。通过从环境因素和栽培措施两个层面对穿心莲内酯合成积累的关键影响因子进行挖掘,有利于建立完善的高品质穿心莲种植体系。此外,对调控穿心莲内酯生物合成的研究进展进行总结和展望,可为穿心莲药材品质提升提供参考。

长江中游新九河段蔡家渡护岸损毁原因及维修对策

护岸工程在航道整治工程中被广泛用于抵御水流冲刷和维持岸线的稳定。由于护岸工程通常布置在原有岸坡易发生崩岸和垮塌的部位,易受水流冲刷而发生损毁,影响其功能的正常发挥。采用实测资料对长江中游新洲—九江河段蔡家渡护岸损毁情况进行分析。结果表明:蔡家渡护岸水下护排头部损毁严重、上游侧出现崩窝,损毁原因主要是大水作用下水流贴岸及大江侧主槽摆动等。在此基础上,分析了维修的必要性,并提出采用“补坡+镇脚”的维修方式,旨在为长江中下游类似护岸建筑物提供参考。

水稻镉污染防治及营养调控研究进展

中国土壤Cd污染严重,长期食用高Cd含量的大米会危害人体健康,因此防控稻米Cd污染对粮食安全具有重要意义。营养调控是降低水稻Cd积累的有效途径,文章整理了近年来水稻Cd污染削减技术和养分调控研究进展,提出可从化肥管理对水稻Cd吸收、转运和积累影响机制等方面开展进一步研究。

用于多气象传感器的模拟前端集成电路设计

设计了一款适用于多气象传感器的模拟前端集成电路,主要包含LDO、可编程增益放大器、SAR ADC以及湿度测量电路。可编程增益放大器采用全差分轨对轨运放作为主体结构来抑制噪声,同时采用连续时间Auto-Zero校准技术来降低其输入失调电压。对于14位SAR ADC,为降低DAC电容阵列的平均功耗和面积,设计了基于V_(CM)-based开关切换策略的分段式差分DAC电容阵列。最后基于湿度传感器电容值与矩形波频率之间关系的原理,设计了湿度测量电路,湿度测量电路频率误差为0.03%。该模拟前端电路基于华虹0.18μm CMOS工艺,并通过Cadence Spectre软件进行电路设计、版图绘制以及仿真验证。后仿真结果表明,电路整体可以实现从输入模拟信号的放大,到最终输出数字码的功能,其有效数(ENOB)为11.40 bit,SINAD为70.37 dB,SNR为71.05 dB,SFDR为83.85 dBc,THD为-78.55 dB。