Capacity-Power Consumption and Energy-Efficiency Evaluation of Green Wireless Networks

In this paper,we discuss in detail the basic issue of green design and consider an energy efficiency function as the metric to evaluate green cellular networks.Specifically,we investigate the transmit power required for an expected transmission capacity and propose a capacity-power formula based on the energy conservation and the Shannon capacity theorem.Two novel definitions of cell interference depth and handoff dynamic model are introduced and the corresponding expression of energy efficiency function is derived.Numerical results show that the energy efficiency function is closely correlated with the transmitted/received power required and the cell radius.Our work provides a useful basis for research and evaluation on green design and technology of cellular networks.

Input-output Efficiency of Elements of Urban Construction Land in Beijing: Empirical Analysis Based on Panel Data of Jurisdiction

Based on the Data Envelopment Analysis method,and by using CCR and BCC model,Super Efficiency model and Malmquist model guided by input efficiency,the input-output efficiency of elements of urban construction land in different jurisdictions of Beijing from 2005 to 2015 was studied.The results showed that there were obvious differences between input-output efficiency of elements of urban construction land in different jurisdictions of Beijing,among which the efficiency of the core area of capital,Yanqing District,Fangshan District and Huairou District was relatively high,while the efficiency of Daxing District,Fengtai District and Miyun District was relatively low.There was no obvious correlation between efficiency differentiation and location factors,which is mainly caused by whether the land use in each jurisdiction has scale effect,whether the technology is improved,whether the input is redundant and whether the output is insufficient.For the jurisdiction of inefficient land use,we should strengthen the consciousness of intensive land use,improve the technical level,appropriately reduce the redundancy of input elements,and pay attention to the output of social and ecological benefits.

Measuring effi ciency of listed tourism companies in China

This study seeks to evaluate the comparative productivity of 32 listed tourism companies which are the main suppliers of China tourism, using the popular methodology known as the data envelopment analysis(DEA). This study analyzes the productivity of listed tourism companies from business and region aspects based on the calculation of Malmquist index. The results show that(1) the overall productivity is non-effi cient(0.954);(2) the productivity of accommodation and catering is biggest, which shows the tourism develops quickly with supports from technology;(3) the productivity in western China is highest, where the economy and tourism attraction are better than other regions; and(4) the effi ciency differences among the listed tourism companies are not signifi cant, and they attribute to the scale effi-ciency, that is the input of the fi nance, resource, talents and policy.

C波段全集成GaN MMIC Doherty功率放大器设计

采用0.25μm氮化镓高电子迁移率晶体管(GaN HEMT)工艺设计了一种全集成单片微波集成电路(MMIC)多尔蒂(Doherty)功率放大器(DPA)。采用了新型的拓扑结构,去除了传统DPA中主路放大器的阻抗变换器以及两路合成后的阻抗转换器,直接在主路输出匹配网络(OMN)中实现饱和点和回退点的阻抗的转换,采取适当的阻抗,与传统电路相比,降低了阻抗转换率,拓宽了频带。此外功率分配器也采用了新颖的拓扑结构,减少了元器件的使用,并且在DPA的匹配网络中使用集总电感的电容降低版图的面积。设计了一款工作在4.6~5.4 GHz的Doherty类功放,版图后仿真结果显示,饱和输出功率为40 dBm,饱和点漏极效率DE为58.9%~61.3%,6 dB回退点的漏极效率为38.3%~45%,增益为8.4~11.3 dB,版图面积为2.4 mm×1.1 mm。

内镜下黏膜切除术(EMR)联合金属夹和穴位贴敷治疗大肠息肉的临床疗效观察

观察内镜下黏膜切除术(endoscopic mucosal resection,EMR)联合金属夹和穴位贴敷治疗大肠息肉的临床疗效。选取2021年10月—2023年10月惠水县中医医院收治的行EMR治疗的大肠息肉患者为研究对象,根据患者具体病情随机将其分为EMR组(n=87例,息肉119枚,行常规EMR治疗)和EMR联合组(n=81例,息肉115枚,行EMR联合金属夹和穴位贴敷治疗)。结果显示,EMR组手术时间短于EMR联合组(P<0.05);术后24 h、48 h、72 h,EMR联合组腹痛、腹胀评分低于EMR组(P<0.05)。研究发现,EMR联合金属夹和穴位贴敷治疗大肠息肉疗效确切,联合使用金属夹可加快创面愈合速度,避免创面感染,从而降低出血、穿孔等并发症发生概率,穴位贴敷可减轻患者术后腹胀、腹痛症状。

运用DRGs的产能和效率提高医保支付管理科学性

目的意义:引入诊断相关组(DRGs)这一管理工具对昆明市定点医疗机构的医疗服务进行评价,为定额结算打下基础。方法 :采集2015年昆明地区6家三级医疗机构病案首页数据,共546422份。使用DRGs的产能和效率2个维度相关指标分析。结论 :采用DRGs工具,实现同一病组不同医疗机构之间可以进行比较,应用权重对资源消耗进行度量,以此评价医疗机构医疗保险基金使用情况,提高了医疗保险基金支付管理的科学性和合理性。

Control performance comparison between tuned liquid damper and tuned liquid column damper using real-time hybrid simulation

Tuned liquid damper (TLD) and tuned liquid column damper (TLCD) are two types of passive control devices that are widely used in structural control. In this study, a real-time hybrid simulation (RTHS) technique is employed to investigate the diff erence in control performance between TLD and TLCD. A series of RTHSs is presented with the premise of the same liquid length, mass ratio, and structural parameters. Herein, TLD and TLCD are physically experimented, and controlled structures are numerically simulated. Then, parametric studies are performed to further evaluate the diff erent performance between TLD and TLCD. Experimental results demonstrate that TLD is more eff ective than TLCD under diff erent amplitude excitations.

“一带一路”沿线省域高技术产业R&D效率提升研究

"一带一路"战略的深入推进为沿线各省高技术产业发展带来重大机遇,紧抓机遇提升R&D效率是关键。本文以2009~2015年"一带一路"沿线15省高技术产业R&D活动为研究对象,采用DEA-Malmquist指数法对其R&D效率进行测度分析。结果显示:"一带一路"沿线省份高技术产业整体R&D效率有待提升;技术进步指数基本呈现下降趋势,而全要素生产率变动与技术进步指数变动情况趋于一致;不同省份推动或阻碍高技术产业R&D效率提升的原因各异。最后,根据研究结论,结合"一带一路"战略,给出有助于R&D效率提升的政策建议。

Research and Development of Cadmium Sulphoselenide Red Pigment

Cadmium sulphoselenide was synthesized continuous substitution solid solution and the only known pigment to yield bright red color on ceramic decoration. Encapsulated cadmium sulphoselenide pigments could yield abundant hues from yellow to red with high opacity at high temperature. The color generation has a linear function relation with the substitution rate. The encapsulation formation process of zirconium silicate encapsulated cadmium sulphoselenide was shown. Insuffi cient encapsulation effi ciency and potential hazard to human and environment had limited the industrial application of cadmium sulphoselenide red pigment. Ink-jet printing decoration required fi ne size cadmium sulphoselenide red pigment on ceramic decoration. The review mainly focused on the synthesis techniques and industrial application of cadmium sulphoselenide red pigment.

Experimental and simulation optimization analysis of the Whipple shields against shaped charge

Occasionally, the Whipple shields are used for the protection of a space station and a satellite against the meteoroids and orbital debris. In the Whipple shields each layer of the shield depletes part of high speed projectile en- ergy either by breaking the projectile or absorbing its energy. Similarly, this investigation uses the Whipple shields against the shaped charge to protect the light armour such as infantry fighting vehicles with a little modification in their design. The unsteady multiple interactions of shaped charge jet with the Whipple shield package against the steady homogeneous target is scrutinized to optimize the shield thickness. Sim- ulations indicate that the shield thickness of 0.75 mm offers an optimum configuration against the shaped charge. Exper- iments also support this evidence.

Active vibration control of tensegrity structures for performance enhancement: A comparative study

This study performs a novel control effi ciency assessment approach that compares performance of optimal control algorithms regarding vibration of tensegrity structures. Due to complex loading conditions and the inherent characteristics of tensegrities, e.g. geometrical nonlinearity, the quantization of control effi ciency in active control of tensegrity constitutes a challenging task especially for diff erent control algorithms. As a fi rst step, an actuator energy input, comprising the strain energy of tensegrity elements and their internal forces work, is set to constant levels for the linearquadratic regulator (LQR). Afterwards, the actuator energy of the linear-quadratic Gaussian (LQG) is iterated with identical actuator energy input in LQR. A double layer tensegrity grid is employed to compare the control effi ciencies between LQR and LQG with fi ve diff erent control scenarios. The results demonstrate the effi ciency and robustness in reducing the dynamic response of tensegrity structures, and a theoretical guideline is provided to search optimal control options in controlling actual tensegrities.

Resource Allocation for Two-Way Amplify and Forward OFDM Relay Networks

Physical-layer network coding(PNC) promises substantial theoretical gain to achieve the maximum system throughput in cooperative relay transmission. However, with the increasing global warming, how to reduce power consumption while satisfy system throughput requirement is becoming a vital issue. In this paper, we investigate energy-efficiency resource allocation(RA) based on PNC with amplify-and-forward(AF) protocol in orthogonal frequency division multiple(OFDM) bidirectional transmission. To minimize the overall transmit power consumption with required system throughput requirement, we consider joint subcarriers and power allocation and formulate the objective task into a constrained optimization problem where the best relay node is selected to minimize total transmit power. The closed form optimization power allocation solutions are acquired by analytical derivation. Based on derivation, we propose a novel optimal energy-efficient power allocation(OE-PA). Numerical results are given to evaluate the performance of the derived scheme as compared to other schemes and show that our scheme has signifi cant improvement to energy saving.

Experimental Investigation of Hydrodynamic Characteristic of a New Rotating Stream Tray

The hydrodynamic characteristic of a new rotating stream tray (NRST) was investigated. The tests were carried out using an air-water/oxygen experimental system in a column with a diameter of 500 mm. The hydrodynamic parameters studied were dry plate pressure drop, wet plate pressure drop, weeping, entrainment, and Murphree liquid effi ciency. The results showed that the NRST has excellent performance in terms of high operational fl exibility. The pressure drop, weeping rate, and entrainment rate remained low even under a high-capacity operation. Correlations of pressure drop, weeping, and entrainment for the NRST were obtained by regression analysis. The results can provide some important theoretical guidance for the development of this type of trays.

A preliminary snapshot of the trophic model and ecosystem attributes of Kaptai reservoir ecosystem, Bangladesh

A mass-balanced Ecopath model presents a quantitative description of the trophic structure,fl ow of energy and trophic interaction among ecological groups of an ecosystem.The Ecopath with Ecosim(EwE)modeling program(Version 6.5)was used to develop a preliminary trophic model for a tropical freshwater reservoir.The total fi sh biomass was 6.245 t/km 2 and the highest trophic level of the reservoir was 3.362(for snakehead).The ecosystem is phytoplankton based because primary producers originated 68%and detritus originated 32%of the total fl ow from lower trophic level.The gross effi ciency of the fi shery was 0.004,suggesting the ineffi ciency of the system.The positive eff ect of phytoplankton and detritus on most of the other groups were evident from mixed trophic analysis while moderately higher ecotrophic effi ciency(EE)of phytoplankton shows the ecosystem’s potential bottom-up control.The competition for the same resources among diff erent groups was also obvious.The ratio of primary production/respiration(1.969)suggests that the ecosystem is at the developing stage and utmost contemplation should be given to concerned human activities.The low value of relative ascendancy(30.13)and overhead(69.87)reveals the stability of the ecosystem and some degrees of maturity.It also predicts the presence of signifi cant strength in reserve of the system to withstand or overcome any perturbation.However,ecologically sustainable resource management plans should be implemented to ensure the sustainability of this reservoir resources.

Comparison in phytoplankton diversity-productivity-community stability between river-type reservoir and lake-type reservoir

Relationship between biodiversity and ecosystem function is one of the core issues in ecological research.Phytoplankton,as the main producer of aquatic ecosystem,its diversity,productivity,and community stability are of great signifi cance to reveal ecosystem function.There are signifi cant diff erences in hydrodynamics,water retention time,and phytoplankton community structure between river-type reservoir and newly built lake-type reservoir.The comparative analysis of phytoplankton community stability between the two types of reservoir has not been reported.Jiuquwan Reservoir(river-type)and Taihu Reservoir(lake-type),the two reservoirs in the Dongjiang River source area of Zhujiang(Pearl)River Basin,were selected for comparison in terms of multi-year operation vs.new impoundment,river-type vs.lake-type,and shallow water vs.sub-deep water reservoirs.Samples were collected in dry season(December 2019),normal season(March 2020),and wet season(August 2020),on which the phytoplankton diversity and productivity of the two reservoirs,and the relationship and diff erence of community stability were examined.Results show that(1)the number of phytoplankton species in Jiuquwan Reservoir decreased comparing that before algal bloom and the restoration treatment,while that in Taihu Reservoir increased compared with that before the impoundment of the reservoir.There was no signifi cant diff erence in functional groups and species number between the two reservoirs(P>0.05);(2)the biological stability,diversity,productivity,and resource utilization effi ciency of newly built lake-type reservoir were higher than those of multi-year river-type reservoir.In addition,the utilization effi ciency of phytoplankton resources was the highest in wet season in both reservoirs.The increases in biodiversity,richness,and evenness promoted the stability of the community,while increases in productivity and resource utilization effi ciency weakened the stability of the community;(3)community stability was aff ected by both biotic and abiotic factors,and hydrodynamic index was the main factor.This study is helpful to understand the relationship and diff erences in phytoplankton diversity,productivity and community stability in diff erent types of reservoirs,and provides a guidance for maintaining the stability of reservoir water ecosystem and protecting the biodiversity.The relationships between phytoplankton diversity,productivity,and community stability will be investigated in depth,for which a long-term observation will be conducted on the impact of environmental factors and diversity on the local biostability in diff erent types of reservoirs.

基于DEA的贵州省生鲜农产品物流效率评价

本文在对DEA效率评价及生鲜农产品物流效率相关研究的基础上,以2012—2021年贵州省生鲜农产品物流数据为样本,运用DEA模型对其进行分析。研究表明:贵州省各年生鲜农产品物流的综合技术效率、技术效率及规模效率有效性呈现不稳定的状态。本文结合物流效率评价分析结果,提出发展贵州省生鲜农产品物流效率的对策,分别为:加大政府扶持力度、培养冷链物流专业人才、加强生鲜农产品物流基础设施建设、发展第三方物流提升其管理水平等。

Influence of flange location on axial deformation stability of double-hat structure

A new structural configuration with better impact stability for increasing energy absorbing efficiency is found. Based on finite element analysis, deformation modes of double-hat structure under axial impact loading are categorized to find the main reasons that affect deformation stability. It is revealed that, in a double-hat structure, the location of the flanges is highly related to the deform- ation mode and energy absorbing efficiency. Moving the flanges away from their traditional mid-loca- tion may result in more regular and stable deformation mode and achieve higher energy absorbing ef- ficiency. The flange offset value needs to be controlled within a certain range, otherwise, the doub- le-hat structure would tend to deform like a top-hat structure and the energy absorbing efficiency could be compromised. These findings and analyses lead to a new structural design configuration- asymmetric flange locations--for enhancing the deformation mode stability in double-hat structures.

An Experimental Study of Structured Packing in High Pressure Services

Both distillation performance and hydrodynamic study for backmixing by tracer technique were carried out in a high-pressure packed column with 0.15 m inner diameter over a wide range of operating conditions. Isobutane and n-pentane are employed as test mixture in the distillation experiment and air/water is used for the hydrodynamic study. The column is installed with Mellapak 350Y structured packing and the total packing height is 2.0 m. With the increasing operating pressure, the separation efficiency increases slightly while the F-factor corresponding to the maximum efficiency at each pressure is descending. It is noted that, at all operating pressures, with the increase of F-factor, the packing efficiency is slightly higher up to the flooding point. The application of SRP model to high-pressure distillation gives much lower values of HTUOG than those obtained experimentally. An additional term, the height of mixing unit, is introduced to correct the SRP model and improve its accuracy at high pressure. From the tracer experiments, the height of mixing unit for gas phase was found to be larger than that for the liquid phase. From this viewpoint, it is believed that the gas phase backmixing gives more unfavorable influence on the separation efficiency in comparison with liquid phase.

Research on Refractories Technology to Meet the Demands of Steel-making Process

Based on the refractories research of Baosteel, the demands for refractories from the developing steel-making technology as high security, high efficiency, energy saving and environment .friendly are introduced.

RCEP成员国制度质量对中国贸易效率的影响研究

2022年1月1日,RCEP协定正式生效,我国自签署协定以来,通过贸易自由化扩大了出口,拓展了进口渠道,然而参与RCEP协定的国家制度之间仍存在一定差异。本文基于贸易扩展引力模型,采用2010—2019年跨国面板数据,利用随机前沿引力模型展开实证分析。研究表明:(1)制度质量对中国与RCEP成员国之间贸易的作用显著,制度质量的提高可以降低中国与成员国的贸易非效率;(2)政府干预程度、税收、贸易自由度、金融自由度和司法效率的提高有利于贸易效率的提高,而投资自由度和产权保护程度的提高不利于贸易效率的提高;(3)中国与澳大利亚的贸易效率最高,与日本的贸易潜力最大。因此,我国应充分重视成员国的社会政治经济制度,在已有协作的基础上,扩大对外开放,进行有效评估和国际援助。