Comprehensive Techniques for Improving the Utilization Rate of Sows in Large-scale Pig Farms

The main task of sows is to breed piglets. The reproductive performance of sows is different due to different techniques adopted in the production of pig farms, which determines the utilization rate of sows and the number of sows in the pig farms. The article analyzed the reproductive performance of sows from the technical point of view, so that the utilization rate of sows can be paid enough attention in the production of pig farms.It is suggested that the technical training should be strengthened in pig farms to improve the corresponding technical level. Meanwhile, pig farms should make the full use of reproductive performance of sows to obtain the maximum economic benefit.

Study on the Relationships between Utilization Ratios and Conversion Rates of Nitrogen,Phosphorus and Potassium for Wheat

This paper studied the relationships between utilization ratios and conversion rates of nitrogen,phosphorus and potassium for wheat by data mining method based on data of"3414 fertilizer field trials"of wheat by published papers from national soil testing and recommendation since 2005.The results and conclusions were as follows:①the conceptual model of fertilizer utilization ratio of wheat for plot was that,Y N≈a+b×optimum nitrogen application amount+c×optimum fertilizer amount of K+d×rainfall in growth season,Y P≈a+b×optimum fertilizer amount of K+c×rainfall in growth season,Y K≈a+b×temperature in growth season+c×rainfall in growth season-d×optimum yield-e×optimum nitrogen application amount,respectively.②Fertilizer utilization ratio and nutrient conversion rate had 4 kinds of relationships.No significant relationships:13,of which 8 were soil nutrients,the results showed that soil nutrients had little effect on nutrient conversion rate and fertilizer utilization ratio;consistent significant relationships:4,they were all nitrogen and phosphorus,explaining the importance of nitrogen and phosphorus;contrary significant relationships:6,they were all nitrogen and phosphorus,illustrating that phosphorus and nitrogen had inhibitory effect;complementary significant relationships:31,the cause of the complementary phenomenon was that the fertilizer utilization ratio was the measuring index of fertilizer efficiency in one season,while the nutrient conversion rate was the measuring index of fertilizer efficiency in more seasons.It showed that the fertilizer utilization rate was significantly correlated,or the nutrient conversion rate was significantly correlated.

Study on the Relationship between Utilization Ratios and Conversion Rates of Nitrogen,Phosphorus and Potassium for Rice

This paper studied the relationships between utilization ratios and conversion rates of nitrogen,phosphorus and potassium for rice by data mining method based on data of"3414 fertilizer field trials"of rice by published papers from national soil testing and recommendation since 2005.The results and conclusions were as follows:①the conceptual model of fertilizer utilization ratio of rice for plot was that,Y N≈a+b×optimum yield+c×optimum fertilizer amount of K,Y P≈a+b×optimum yield,Y K≈a respectively.②Fertilizer utilization ratio and nutrient conversion rate had 4 kinds of relationships:①no significant relationships:25,of which 14 were soil nutrients and 9 were environmental factors,the results showed that soil nutrients and environmental factors had little effect on nutrient yield ratio and fertilizer utilization ratio;②consistent significant relationships:2,one was that yield ratio and utilization ratio of N were positively correlated with the optimum production,explaining the importance of N for production,the other was that yield ratio and utilization ratio of P had a significantly positive correlation with conversion rate and utilization ratio of N,illustrating that nitrogen and phosphorus had mutual promotion;③contrary significant relationships:5,these showed as negative correlations of fertilizer utilization ratio and positive correlation of nutrient conversion ratio;④complementary significant relationships:22,the cause of the complementary phenomenon was that the fertilizer utilization ratio was the index of fertilizer efficiency in one season,while the nutrient conversion rate was the index of fertilizer efficiency in more seasons,which showed that the fertilizer utilization rate was significantly correlated,or the nutrient conversion rate was significantly correlated.

Study on the Relationships between Utilization Ratios and Conversion Rates of Nitrogen,Phosphorus and Potassium for Maize

This paper studied the relationships between utilization ratios and conversion rates of nitrogen,phosphorus and potassium for maize by data mining method based on data of"3414 fertilizer field trials"of maize by published papers from national soil testing and recommendation since 2005.The results and conclusions were as follows:①the conceptual model of fertilizer utilization ratio of maize for plot was that,Y N≈a+b×optimum yield,Y P≈a+b×optimum yield-c×optimum nitrogen application amount-d×optimum potassium application amount,Y K≈a-b×optimum nitrogen application amount-c×temperature in growth season-d×rainfall in growth season,respectively.②Fertilizer utilization ratio and nutrient conversion rate had 4 kinds of relationships.No significant relationships:22,of which 16 were soil nutrients and 5 were environmental factors,the results showed that soil nutrients and environmental factors had little effect on nutrient conversion rate and fertilizer utilization ratio;consistent significant relationships:14,illustrating that conversion rate and utilization ratio of maize were consistent in most cases,and it was because that maize was planted for a long term,and its fertilizer absorption law was basically stable;contrary significant relationships:0,illustrating that there was no reverse relationship between conversion rate and utilization ratio of maize;complementary significant relationships:18,the cause of the complementary phenomenon was that the fertilizer utilization ratio was the measuring index of fertilizer efficiency in one season,while the nutrient conversion rate was the measuring index of fertilizer efficiency in more seasons.It showed that the fertilizer utilization ratio was significantly correlated,or the nutrient conversion rate was significantly correlated.

Study on the Nitrogen Release Law of Bamboo Charcoal-coated Urea and Its Biological Utilization Effects

[Objective] The study about the nitrogen releasing law of bamboo-charcoal coated urea and the biologic utilization effect was to find the coated urea with high efficiency,low price and simple production technology.[Method]Two kinds of bamboo-charcoal coated urea(BCCU)with different coating thickness were made by using bamboo-charcoal and macromolecule polymer as coating material.The experiments of soil eluviate,ammonia volatilization in corn field and potted plant of corn were conducted to study the nitrogen releasing law and the biologic utilization effect of self-made BCCU.[Result]The BCCU showed some slow-release capability and their accumulated nitrogen releasing rates in 29 d were 9.93%-16.27% lower than that of normal urea.Compared with the normal urea,the volatilization rate of ammonia in BCCU reduced to 16.66%-31.8%,the biomass of corn and nitrogen utilization rate increased by 12.8%-24.1% and 10.5%-16.99%,respectively.[Conclusion]Bamboo-charcoal in coated urea not only had some slow-release capability,but also had some adsorbability,which would reduce the eluviation and volatilization of nitrogen and protect environment from N pollution.

Ammonia Volatilization and Nitrogen Utilization Efficiency in Response to Urea Application in Rice Fields of the Taihu Lake Region,China

Ammonia volatilization losses, nitrogen utilization efficiency, and rice yields in response to urea application to a rice field were investigated in Wangzhuang Town, Changshu City, Jiangsu Province, China. The N fertilizer treatments, applied in triplicate, were 0 （control）, 100, 200, 300, or 350 kg N ha^-1. After urea was applied to the surface water, a continuous airflow enclosure method was used to measure ammonia volatilization in the paddy field. Total N losses through ammonia volatilization generally increased with the N application rate, and the two higher N application rates （300 and 350 kg N ha^-1） showed a higher ratio of N lost through ammonia volatilization to applied N. Total ammonia loss by ammonia volatilization during the entire rice growth stage ranged from 9.0% to 16.7% of the applied N. Increasing the application rate generally decreased the ratio of N in the seed to N in the plant. For all N treatments, the nitrogen fertilizer utilization efficiency ranged from 30.9% to 45.9%. Surplus N with the highest N rate resulted in lodging of rice plants, a decreased rate of nitrogen fertilizer utilization, and reduced rice yields. Calculated from this experiment, the most economical N fertilizer application rate was 227 kg ha^-1 for the type of paddy soil in the Taihu Lake region. However, recommending an appropriate N fertilizer application rate such that the plant growth is enhanced and ammonia loss is reduced could improve the N utilization efficiency of rice.

Improving energy utilization efficiency of electrical discharge milling in titanium alloys machining

Electrical discharge milling(ED-milling) can be a good choice for titanium alloys machining and it was proven that its machining efficiency can be improved to compete with mechanical cutting. In order to improve energy utilization efficiency of ED-milling process, unstable arc discharge and stable arc discharge combined with normal discharge were implemented for material removal by adjusting servo control strategy. The influence of electrode rotating speed and dielectric flushing pressure on machining performance was investigated by experiments. It was found that the rotating of electrode could move the position of discharge plasma channel, and high pressure flushing could wash melted debris out the discharge gap effectively. Both electrode rotating motion and high pressure flushing are contributed to the improvement of machining efficiency.

Effects of Increased Planting Density with ReducedNitrogen Application on Yield Formation and NitrogenUtilization of Autumn Maize

With the change of cropping system in the middle reaches of the Yangtze River,the planting area of autumn maize is gradually increasing.However,the cultivation techniques are still under improvement for higher yield and nitrogen efficiency of autumn maize.Increase in planting density with reduced nitrogen fertilizer application is one of the important paths to achieve high yield and high nitrogen utilization efficiency.Meanwhile,the effect needs to be verified for autumn maize.The semi-compact autumn maize variety Qinyu 58 was planted under different planting densities and nitrogen fertilizer amounts with the split plot design.Different nitrogen application rates were arranged in the main plots,including the conventional nitrogen application(N300,300 kg/hm^2),30%reduction from the conventional treatment(N210,210 kg/hm^2)and no nitrogen application(N0).Different planting densities were arranged in the sub-split plots,including the conventional planting density(D60,60000 plants/hm2),medium density(D78,78000 plants/hm^2)and high density(D93,93000 plants/hm2).The effects of nitrogen fertilizer,planting density and their interaction effects on canopy structure,dry matter accumulation,yield and nitrogen use efficiency of autumn maize were studied.The nitrogen application rate and planting density had obvious interaction effects on the yield formation of autumn maize.Compared with the conventional cultivation(N300D60),increasing the planting density with 30%reduction in nitrogen application(N210)can obviously increase the canopy light interception rate,LAI,dry matter accumulation and yield.However,there was no significant change in canopy light interception rate,LAI,dry matter accumulation,grain weight and yield between D93 and D78.Compared with N300D60,nitrogen translocation efficiency and nitrogen contribution proportion to grain nitrogen did not change significantly in autumn maize grown under N210 and D78 treatments,whereas nitrogen partial productivity,nitrogen agronomic efficiency and recovery and utilization efficiency of nitrogen fertilizer increased significantly.Moreover,high density(D93)planting at N210 plots significantly improved nitrogen transport efficiency and utilization efficiency in autumn maize.Therefore,the suitable planting density of the autumn maize variety Qinyu 58 in Hubei Province is recommended a value of 78000 plants/hm^2,with the nitrogen application rate of 210 kg/hm2,which can achieve the target of higher yield by increasing density and reducing nitrogen.

New technique of comprehensive utilization of spent Al_2O_3-based catalyst

A new technology was developed to recover multiple valuable elements from the spent Al2O3-based catalyst by X-ray phase analysis and exploratory experiments. The experimental results show that in the condition of roasting temperature of 750℃ and roasting time of 30 min, molar ratio of Na2O to Al2O3 of 1.2, the leaching rates of alumina, vanadium and molybdenum in the spent catalyst are 97.2%, 95.8% and 98.9%, respectively. Vanadium and molybdenum in sodium aluminate solution can be recovered by precipitators A and B, and the precipitation rates of vanadium and molybdenum are 94.8% and 92.6%. Al（OH）3 was prepared from sodium aluminate solution in the carbonation decomposition process, and the purity of Al2O3 is 99.9% after calcination, the recovery of alumina reaches 90.6% in the whole process; the Ni-Co concentrate was leached by sulfuric acid, a nickel recovery of 98.2% and cobalt recovery over 98.5% can be obtained under the experimental condition of 30% H2SO4, 80℃, reaction time 4 h, mass ratio of liquid to solid 8, stirring rate 800r/min.

Effects of Different Nitrogen Levels on Growth and Nitrogen Utilization of Sugarcane

[Objectives]To systematically study the effects of different nitrogen levels on the growth and nitrogen utilization of sugarcane in Guangxi.[Methods]Through field experiment and indoor analysis,different nitrogen application levels were set up to determine soil nitrogen content and sugarcane nitrogen content.The effects of different nitrogen levels on sugarcane yield,agronomic characters and nitrogen utilization were studied.[Results]The effect of nitrogen application rate on sugarcane yield showed a quadratic curve,and nitrogen application could significantly increase sugarcane yield,and the sugarcane yield reached the maximum when the nitrogen application rate reached 714 kg/ha.[Conclusions]With the increase of nitrogen application rate,sugarcane yield increased,but when it exceeded a certain range,the sugarcane yield decreased significantly.

A Cross-Sectional Study of Utilization of Green Building Rating Tools by Selected Professionals in the Zambian Building Industry

Green building rating tools used for planning and assessing the impact of buildings on the environment are continually revised in line with user needs. The appropriateness of tools for the Zambian building industry depends on whether the tools adequately meet minimum green buildings standards and the country’s environmental aspirations. The utilization of green building rating tools is important if Zambia is to achieve the real benefits of green buildings, however very little is known about the levels of utilization in Zambia. A cross-sectional study of 115 professionals from the building industry in Zambia was undertaken using a sequential mixed method approach, to investigate the level of utilization, preferred criteria and, the barriers and drivers to the utilization of tools. The significance of the study was that it demonstrated the association between utilization of green building rating tools and environmental, technological, economic, and social green buildings practices by selected professionals in the Zambian building industry. There is a need to use materials and practices that are locally based and promote the local economy. The technical needs were met in tools, that were considered easy to use, interesting and comprehensive. Some of the green building rating tools were considered unsuitable due to the absence of appropriate criteria and the main economic challenge was the high cost of certification. The association was significant between utilization and those involved in a variety of projects than those who were involved in only residential buildings. Barriers to utilization were a lack of government regulations on green buildings designs and the high cost of certification. The drivers were environmental benefits, the interest of developers in green buildings, and having technical skills. The study recommends a review of the current building regulations to include green buildings practices and materials and adaptation of appropriate rating tools.

Impact of index admission cholecystectomy vs interval cholecystectomy on readmission rate in acute cholangitis: National Readmission Database survey

BACKGROUND Elective cholecystectomy(CCY)is recommended for patients with gallstone-related acute cholangitis(AC)following endoscopic decompression to prevent recurrent biliary events.However,the optimal timing and implications of CCY remain unclear.AIM To examine the impact of same-admission CCY compared to interval CCY on patients with gallstone-related AC using the National Readmission Database(NRD).METHODS We queried the NRD to identify all gallstone-related AC hospitalizations in adult patients with and without the same admission CCY between 2016 and 2020.Our primary outcome was all-cause 30-d readmission rates,and secondary outcomes included in-hospital mortality,length of stay(LOS),and hospitalization cost.RESULTS Among the 124964 gallstone-related AC hospitalizations,only 14.67%underwent the same admission CCY.The all-cause 30-d readmissions in the same admission CCY group were almost half that of the non-CCY group(5.56%vs 11.50%).Patients in the same admission CCY group had a longer mean LOS and higher hospitalization costs attrib-utable to surgery.Although the most common reason for readmission was sepsis in both groups,the second most common reason was AC in the interval CCY group.CONCLUSION Our study suggests that patients with gallstone-related AC who do not undergo the same admission CCY have twice the risk of readmission compared to those who undergo CCY during the same admission.These readmis-sions can potentially be prevented by performing same-admission CCY in appropriate patients,which may reduce subsequent hospitalization costs secondary to readmissions.

建筑厂房机电安装工程管线布置现状及优化路径

为了优化建筑厂房机电安装工程管线布置,增强机电安装工程施工效率,文章探讨了建筑厂房机电安装工程管线布置现状,当前施工过程中存在前期规划不充分、管线碰撞、重复施工等问题,管线材料物流管理不畅,影响了布置效率与施工活动的顺利开展。为此提出建筑厂房机电安装工程管线布置的优化路径,要求科学选取交叉点位置,设置适宜的管线净高度,科学进行施工设计,加强管线分类管理,增强管线综合布置效果。以贵阳经开区产业集群某厂房项目为例,总结提高工程效率的策略与具体做法。该研究结果为工业厂房的高效管线布局提供了一定参考,以此促进建筑业资源的合理利用。

Effects of mechanized deep placement of nitrogen fertilizer rate and type on rice yield and nitrogen use efficiency in Chuanxi Plain, China

This paper investigates the yield and nitrogen use efficiency (NUE) of machine-transplanted rice cultivated using mechanized deep placement of N fertilizer in the rice–wheat rotation region of Chuanxi Plain,China.It provides theoretical support for N-saving and improves quality and production efficiency of machine-transplanted rice.Using a single-factor complete randomized block design in field experiments in 2018 and 2019,seven N-fertilization treatments were applied,with the fertilizer being surface broadcast and/or mechanically placed beside the seedlings at (5.5±0.5) cm soil depth when transplanting.The treatments were:N0,no N fertilizer;U1,180 kg N ha^(–1) as urea,surface broadcast manually before transplanting;U2,108 kg N ha^(–1) as urea,surface broadcast manually before transplanting,and 72 kg N ha^(–1) as urea surface broadcast manually on the 10th d after transplanting,which is not only the local common fertilization method,but also the reference treatment;UD,180 kg N ha^(–1) as urea,mechanically deep-placed when transplanting;M1,81.6 kg N ha^(–1) as urea and 38.4 kg N ha^(–1) as controlled-release urea (CRU),mechanically deep-placed when transplanting;M2,102 kg N ha^(–1) as urea and48 kg N ha^(–1) as CRU,mechanically deep-placed when transplanting;M3,122.4 kg N ha^(–1) as urea and 57.6 kg N ha^(–1) as CRU,mechanically deep-placed when transplanting.The effects of the N fertilizer treatments on rice yield and NUE were consistent in the 2 yr.With a N application rate of 180 kg ha^(–1),compared with U2,the N recovery efficiency (NRE),N agronomic use efficiency (NAE) and yield under the UD treatment were 20.6,3.5 and 1.1% higher in 2018,and 4.6,1.7 and 1.2% higher in 2019,respectively.Compared with urea alone (U1,U2 or UD),the NRE,NAE and yield achieved by M3 (combined application of urea and controlled-release urea) were higher by 9.2–73.3%,18.6–61.5% and 6.5–16.5%(2018),and 22.2–65.2%,25.6–75.0% and 5.9–13.9%(2019),respectively.Compared with M3,the lower-N treatments M1 and M2 significantly increased NRE by 4.0–7.8% in 2018 and 3.1–4.3% in 2019,respectively.Compared with urea surface application (U1 or U2),the yield under the M2 treatment was higher by 4.3–12.9% in 2018 and 3.6–10.1% in 2019,respectively.Compared with U2,the NRE and NAE under the M2 treatment was higher by 36.9 and 36.3% in 2018,and 33.2 and 37.4% in 2019,mainly because of higher N uptake.There was no significant difference in the concentration of nitrate in the top 0–20 cm soil under U1,U2 and M2 treatments during the full heading and maturity stages.During the full heading stage,U2 produced the highest concentration of nitrite in 0–20 cm and 20–40 cm soil among the N fertilizer treatments.In conclusion,mechanized deep placement of mixed urea and controlled-release urea (M2) at transplanting is a highly-efficient cultivation technology that enables increased yield of machine-transplanted rice and improved NUE,while reducing the amount of N-fertilization applied.

Developmental Potential and Clinical Value of Embryos with Abnormal Cleavage Rate

To investigate the developmental potential and clinical value of embryos with abnormal cleavage rate,a retrospective analysis was performed on 66 635 2-prokaryotic(2PN)and 1-pronuclear(1PN)embryos.The embryos were given conventionally in vitro fertilization(IVF)treatment and continuously cultured on the day 3(D3)at the Reproductive Medicine Center,Tongji Medical College,Huazhong University of Science and Technology from January 2016 to December 2017.The embryos were separated into the day-2(D2)undivided group with 106 cases,the arrested development group with 3482 cases,the blastomere reduction group with 541 cases,and the control group with 62 506 cases,respectively.The blastocyst utilization rates of these three abnormal groups were 2.83%,10.86%and 6.84%,respectively,which were significantly different from that in control group(39.46%).Furthermore,2 cases of anabiosis and 1 case of live birth were found in D2 undivided group.In arrested development group,there were 55 cases of anabiosis,11 cases of clinical pregnancy in single-embryo transplantation(including 6 cases of live birth),and 25 cases of clinical pregnancy in combination with one normal embryo transplantation(including 23 cases of live births and 15 cases of dizygotic twins under B-ultrasound).There were 13 case of anabiosis in blastomere reduction group:there was 1 case of single embryo transplantation and clinical pregnancy was obtained;there were also 6 cases of clinical pregnancy in combination with one single normal embryo transplantation(including 5 cases of live births and 2 cases of di2ygotic twins under B-ultrasound).In conclusion,embryos with abnormal cleavage rate still have the potential to continue to develop,and have certain blastocyst utilization rate and live birth.

Enhanced Data Transmission Rate of XCTD Profiler Based on OFDM

An expendable conductivity-temperature-depth profiler(XCTD)is one of the most important instruments used to obtain hydrological data,such as temperature and conductivity,and detect ocean depth in a large area.However,the XCTD channel provides poor time-varying performance,narrowband,and low signal-to-noise ratio(SNR),which severely restricts the data transmission rate.In contrast to conventional single-carrier modulation techniques,such as amplitude-shift keying and differential phase-shift keying,this article provides a new method,based on orthogonal frequency division multiplexing(OFDM)to enhance the data transmission rate of deep-sea abandoned profilers.We apply the OFDM to enhance the SNR of the XCTD,which is achieved by reducing the data transmission rate of each sub-channel.Moreover,the bandwidth utilization may be improved by increasing the number of subcarriers in a given bandwidth,which enhances the data transmission rate.Based on analysis of the XCTD channel model,OFDM with different parameters such as constellation mapping,number of subcarriers,subcarrier spacing,signal period and cyclic prefix are achieved.To verify the effectiveness of the OFDM,this study investigates the influence of different parameters on the data transmission rate at different noise levels,i.e.,-20 dB and-40 d B.

Rate Allocation Scheme for Machine-to-Machine Service Based on 3GPP in Heterogeneous Wireless Networks

In this study,an explicit adaptive traffic allocation scheme for Machine-to-Machine(M2M)service is proposed to achieve optimum distribution in heterogeneous networks.Based on the characteristics of M2M services,the presented scheme is formulated as a convex optimization problem that maximises the utility of the M2M service,and then determines how to allocate the total rate among the multiple access networks.The analysis and numerical simulations indicate that the proposed scheme makes a significant improvement in performance compared with the traditional schemes.

REGROWTH OF MBE-GaAs FILMS ON Si SUBSTRATES BY HIGH ENERGY ION-IMPLANTATION AND SUBSEQUENT ANNEALING

4.2MeV ^(7)Li channeling technique,laser Raman scattering spectrometry,and TEM have been utilized to study the regrowth of MBE-GaAs films of〜μm thick on Si substrates by Si^(+) implantation(0.6-2.6MeV)and subsequent rapid thermal annealing.The results showed that crystalline disorder was greatly reduced in the recrystalized layers especially at the interface.

Comprehensive Utility Function for Resource Allocation in Mobile Edge Computing

In mobile edge computing(MEC),one of the important challenges is how much resources of which mobile edge server(MES)should be allocated to which user equipment(UE).The existing resource allocation schemes only consider CPU as the requested resource and assume utility for MESs as either a random variable or dependent on the requested CPU only.This paper presents a novel comprehensive utility function for resource allocation in MEC.The utility function considers the heterogeneous nature of applications that a UE offloads to MES.The proposed utility function considers all important parameters,including CPU,RAM,hard disk space,required time,and distance,to calculate a more realistic utility value for MESs.Moreover,we improve upon some general algorithms,used for resource allocation in MEC and cloud computing,by considering our proposed utility function.We name the improved versions of these resource allocation schemes as comprehensive resource allocation schemes.The UE requests are modeled to represent the amount of resources requested by the UE as well as the time for which the UE has requested these resources.The utility function depends upon the UE requests and the distance between UEs and MES,and serves as a realistic means of comparison between different types of UE requests.Choosing(or selecting)an optimal MES with the optimal amount of resources to be allocated to each UE request is a challenging task.We show that MES resource allocation is sub-optimal if CPU is the only resource considered.By taking into account the other resources,i.e.,RAM,disk space,request time,and distance in the utility function,we demonstrate improvement in the resource allocation algorithms in terms of service rate,utility,and MES energy consumption.

基于多维空间的航路利用率

航路利用率表征了空域中航路的利用情况,通过计算航路利用率可以实现对空域资源进行更合理、高效的利用。为了更加准确地计算给定时间段内固定航路的利用率,通过构建抽象的三维空间,提出了一种基于多维空间的航路利用率计算方法。在考虑时间和空间两个角度之间的相互联系有了突破,从时间、航路、高度层三个维度建立航路时空利用率计算模型计算航路时空利用率,结合航路容量利用率,从时间、空间、容量三个角度出发,建立了航路利用率计算模型。最后通过算例分析计算得到某一空域四条航路的利用率。