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Relationship between the Current Account Balance Ratio and Salary Ratio in Japanese Municipal Hospitals
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作者 Nozomu Mandai Mayumi Watanabe 《Health》 2019年第12期1591-1597,共7页
Background: While public municipal hospitals in Japan are supported by public financing and are less likely to fail than private hospitals, more than half are in financial deficit. Hospitals running at a deficit may h... Background: While public municipal hospitals in Japan are supported by public financing and are less likely to fail than private hospitals, more than half are in financial deficit. Hospitals running at a deficit may have poorer outcomes and less investment in maintenance of human or physical capital, as well as increased rates of patient adverse events. We sought to clarify the relationship between municipal hospital surpluses or deficits and salary expenditures. Methods: We extracted financial data for 253 general hospitals of 300 beds or more from financial statements for the 2013 fiscal year available in the Yearbook of Public Firms, Edition for Hospital. From these data, we calculated account balance ratios and compared the average value of the ratio of labor to the output (salary ratio) for each group using analysis of variance (ANOVA). Results: The salary ratios of hospitals in the surplus group were significantly lower than the salary ratios of hospitals in the deficit group (55.5% vs. 49.4%;p p = 0.342). In the surplus group, the average value of salary ratios was different among the three-bed count groups (mean salary ratio: 53.0% vs. 48.5% vs. 47.4%;ANOVA p = 0.012). In addition, there was a significant difference in mean value between the 300-bed group and ≥500 beds group (mean salary ratio: 53.0% vs. 47.4%;p = 0.002). Conclusion: This study suggests that maintaining a favorable salary ratio to the current account balance is a useful proxy of fiscal health, and interventions to improve the salary ratio may be effective in improving municipal hospital management. Furthermore, among well-managed municipal hospitals, larger hospital size may confer some advantage in purchasing power. 展开更多
关键词 HOSPITAL FINANCE SALARY ratio Public HOSPITAL Current ACCOUNT balance ratio
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Study on the Micrometeorological Characteristics and Energy Balance of Winter Wheat Canopy 被引量:1
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作者 韩笑 李永秀 《Meteorological and Environmental Research》 CAS 2010年第9期81-86,共6页
[Objective] The micrometeorology features and energy balance of winter wheat canopy were studied.[Method] By means of micrometeorological data of winter wheat canopy at booting stage,heading and flowering stage,fillin... [Objective] The micrometeorology features and energy balance of winter wheat canopy were studied.[Method] By means of micrometeorological data of winter wheat canopy at booting stage,heading and flowering stage,filling stage and mature stage and the data from local meteorological station,the temporal and spatial variation law of micrometeorology features of winter wheat canopy were researched,and the daily and seasonal variation of energy balance were further analyzed.[Result] The daily variation of winter wheat canopy temperature and air temperature showed sinusoidal trend,and air temperature changed with height,while temperature was highest at heading and flowering stage.The daily variation of humidity also showed sinusoidal trend,and humidity was highest and saturation deficit was lowest in the middle of canopy,while the maximum humidity appeared at heading and flowering stage.In addition,the daily variation of wind speed in the upper canopy showed single peak trend.There was obvious daily variation and seasonal variation of energy balance in winter wheat field,and the daily variation of net radiation also showed single peak trend,while sensible heat flux was highest at filling stage and lowest at heading and flowering stage,and latent heat flux was highest at heading and flowering stage and lowest at booting stage.[Conclusion] Our study could provide scientific evidence for the study of disaster prevention and mitigation and the improvement of yield and quality of winter wheat. 展开更多
关键词 Winter wheat CANOPY MICROMETEOROLOGY Energy balance Bowen ratio China
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An investigation on changes in glacier mass balance and hypsometry for a small mountainous glacier in the northeastern Tibetan Plateau 被引量:2
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作者 CAO Bo PAN Bao-tian +1 位作者 CAI Ming-yong WANG Jie 《Journal of Mountain Science》 SCIE CSCD 2017年第8期1624-1632,共9页
Mass balance is a key indicator of the sensitivity of glaciers to climate change. Field measurement is one of the most important ways to study the mass balance of glaciers. Based on observations of mass balance in the... Mass balance is a key indicator of the sensitivity of glaciers to climate change. Field measurement is one of the most important ways to study the mass balance of glaciers. Based on observations of mass balance in the ablation zone of Shuiguan Glacier No.4, Qilian Mountains, China, combined with the balance ratio between accumulation and ablation, we established a linear relation between mass balance and altitude. The results show that the mean annual mass balance of this glacier was ~510 mm w.e. from 2010 to 2013. The uncertainty in the balance ratio value does not lead to a significant difference in the mass balance. The equilibrium-line altitude rose by 180 m from 1972 to 2013, while the accumulation–area ratio decreased from 0.68 to 0.25. These variations may be caused by changes in air temperature. Meanwhile, the glacier is at present not in a steady state, and it may continue to shrink by a further ~900 m, even without further climate warming. In the western Lenglongling Mountains, assuming that the glaciers are in a steady state and the Equilibrium-line altitudes(ELAs)remain similar, there will be only 46 glaciers left, covering a total area of 19.2 km^2, in other words, only 22.3% of the glaciers area in 1972. 展开更多
关键词 Accumulation-area ratio (AAR) Equilibrium-line altitude (ELA) GLACIER mass balance
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China's Sovereign Balance Sheet and Its Risk Assessment 被引量:1
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作者 李扬 张晓晶 +2 位作者 常欣 汤铎铎 李成 《China Economist》 2012年第6期78-89,共12页
Using available data and necessary estimations, this paper provides a tentative picture of the balance sheet of China's sovereign account between 2000 and 2010. The main findings indicate that the net worth of China... Using available data and necessary estimations, this paper provides a tentative picture of the balance sheet of China's sovereign account between 2000 and 2010. The main findings indicate that the net worth of China's sovereign assets had been positive and increasing during the period under review. This implies that the Chinese government has sufficient sovereign assets to cover its sovereign liabilities, therefore the likelihood of a sovereign debt crisis in China is extremely low in the near term. Moreover, although China's leverage ratio (total liabilities/GDP) is far lower compared to advanced economies, it seems higher than that of other major emerging economies such as Brazil, Russia, and India (BRIC). In fact, the leverage ratio has been increasing rapidly over recent years and requires special attention. In particular, according to sector-specific analysis, high corporate liability ratios (percentage to GDP) constitute a major concern of China's national balance sheet. In 2010, this liability ratio exceeded l OO percent, which exceeds the 90 percent level observed in OECD countries. Lastly, this paper concludes that a sustainable economic growth and structural transformation of growth model are the fundamental means to taming China's balance sheet risks. 展开更多
关键词 balance sheet approach sovereign balance sheet leverage ratio transformation of development pattern.
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Mineral Balance Plasticity of Cloudberry (<i>Rubus chamaemorus</i>) in Quebec-Labrador Bogs
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作者 Léon Etienne Parent Serge-étienne Parent +2 位作者 Valérie Hébert-Gentile Kristine Naess Line Lapointe 《American Journal of Plant Sciences》 2013年第7期1508-1520,共13页
The “ionome”, or plant elemental signature, is the elemental composition of an organisms, that may vary with genotypic traits and phenotypic plasticity. Cloudberry (Rubus chamaemorus L.) is a circumboreal wild berry... The “ionome”, or plant elemental signature, is the elemental composition of an organisms, that may vary with genotypic traits and phenotypic plasticity. Cloudberry (Rubus chamaemorus L.) is a circumboreal wild berry naturally growing in oligotrophic oceanic bogs ofQuebecandLabrador. Our objective was to relate cloudberry stand productivity to the ionomes of female ramets and explore the cause of nutrient imbalance in low-performing stands. We analyzed 13 elements in female ramets collected in 86 natural sites where crop productivity varied widely. We computed orthogonally arranged balances reflecting plant stoichiometric rules and soil biogeochemistry. Balances were expressed as isometric log ratios (ilr) between ad hoc sub-compositions. Balances were synthesized into a Mahalanobis distance optimized based on receiving operating characteristics (ROC). The critical Mahalanobis distance was found to be 5.29 for cutoff berry yield of3.8 g.m-2 with test performance of 0.88, as measured by the area under the ROC curve. Although past research on cloudberry focused mainly on the N/P ratio, this exploratory mineral balance analysis indicated that imbalance in the [P,N | S,C] and [Al | Nutrients] partitions appeared to be the factors limiting the most cloudberry productivity in the bogs. Some highly productive stands showed relatively high C fixation and K use efficiency. Due to the complexity of interactions, diagnosis should be conducted computing first a global imbalance index (Mahalanobis distance), then examining in the balance domain binary partitions departing most from reference, and finally appreciating relative shortage, sufficiency or excess of elements in the concentration domain. 展开更多
关键词 Al Toxicity Cloudberry Compositional Data Analysis ISOMETRIC Log ratio NUTRIENT balance Ionome
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Relating Demography to Trade Imbalances through Theoretical Modeling and Numerical Simulation
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作者 杨继军 马野青 《China Economist》 2011年第6期92-101,共10页
Demographic transitions occur at different times and speed across different economies, and age structures consequently differ across regions. Using a solvable four-phase model, we show that economies with a higher pro... Demographic transitions occur at different times and speed across different economies, and age structures consequently differ across regions. Using a solvable four-phase model, we show that economies with a higher proportion of working-age force and a lower dependency ratio tend to have higher savings rates. Because the demographic " center of gravity"for investment demand falls at a younger point in the age distribution than that of savings supply, countries with a younger age-distribution like those described above generate national savings in excess of domestic investment, resulting in a current account surplus. Numerical simulation supports this hypothesis. But the relative youth or age of a country's population reflects temporary demographic trends which change continuously. Therefore, while trade imbalances caused by demographic factors are structural and long-term, they are not permanent, and may be reversed by changes in age structure. 展开更多
关键词 age structure dependency ratio demographic transition current account balance
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Simulation Analysis of Balance Detection Technique in Coherent Optical Receiver
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作者 Piaokun Zhang Zhongwei Tan +1 位作者 Zhichao Ding Lijun Guo 《Optics and Photonics Journal》 2021年第8期301-313,共13页
<div style="text-align:justify;"> This paper introduces the working principle of the balanced heterodyne detection system, establishes the corresponding mathematical model, deduces the signal to noise ... <div style="text-align:justify;"> This paper introduces the working principle of the balanced heterodyne detection system, establishes the corresponding mathematical model, deduces the signal to noise ratio (SNR) formula of the balanced heterodyne detection. By comparing balance heterodyne detection with general coherent detection with MATLAB numerical simulation, the superiority of balance heterodyne detection system is proved theoretically. Finally, the simulation models of ordinary heterodyne detection, balance detection and double balance detection system are built by OptiSystem. The simulation results are consistent with the conclusions derived from the mathematical analysis, which provides a new method for the research of weak laser detection technology. </div> 展开更多
关键词 balance Heterodyne Detection 90? Optical Mixer Signal to Noise ratio The Numerical Simulation
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Actual Evapotranspiration Estimation Using Remote Sensing: Comparison of SEBAL and SSEB Approaches 被引量:2
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作者 Bergson G. Bezerra Bernardo B. da Silva +1 位作者 Carlos A. C. dos Santos José R. C. Bezerra 《Advances in Remote Sensing》 2015年第3期234-247,共14页
The main objective of this paper was to evaluate the daily actual evapotranspiration (ET) accuracy obtained by remote sensing algorithms when compared with Bowen ratio measurements performed in the cotton fields. The ... The main objective of this paper was to evaluate the daily actual evapotranspiration (ET) accuracy obtained by remote sensing algorithms when compared with Bowen ratio measurements performed in the cotton fields. The experiment was conducted in a cotton experimental field of EMBRAPA located in Ceará State, Brazil. Seven TM Landsat-5 images acquired in 2005 and 2008 were used to perform SEBAL and SSEB algorithms. The comparison between the estimated values by remoting sensing algorithms and the measured values in situ showed an acceptable accuracy. Besides, SSEB algorithm showed to be an important tool for ET analysis in the semi-arid regions, due to the fact that it does not need the meteorological data to solve the energy balance, but only the average temperature of the “hot” and “cold” pixels. Additionally, SSEB presents simpler processing than SEBAL algorithm that needs to solve an iterative process to obtain the sensible heat flux values. 展开更多
关键词 Energy balance LANDSAT EVAPOTRANSPIratioN BOWEN ratio SEMI-ARID
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Study on determination of the stable slope configuration for deep open pit mine 被引量:1
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作者 Nai-long ZHU Shi-xiong ZHANG Shu-yu YUE 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第9期1208-1213,共6页
The space effects of deep pit slope are analyzed by an elastic mechanics principle. The interaction among the critical slide angle, the friction coefficient, the cohesion, and the horizontal radius of the deep pits is... The space effects of deep pit slope are analyzed by an elastic mechanics principle. The interaction among the critical slide angle, the friction coefficient, the cohesion, and the horizontal radius of the deep pits is derived in this paper. It indicates that the deeper the pit is excavated, the greater the critical slide angle is. Both the theory for reducing stripping waste rock in deep pit and the approach to determining the configuration of the stable slope are developed from the interaction. The theory in this paper comprises the preceding principles of stability analysis of slopes and is suitable for analyzing that of deep pit. 展开更多
关键词 Elastic mechanics Deep pit Slope stability Critical slide angle ratio of stripping-to-ore
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Evapotranspiration Characteristics of a Lowland Dry Evergreen Forest in Central Cambodia Examined Using a Multilayer Model
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作者 Tatsuhiko NOBUHIRO Akira SHIMIZU +6 位作者 Katsunori TANAKA Koji TAMAI Naoki KABEYA Eriko ITO Takanori SHIMIZU Makoto ARAKI Sophal CHANN 《Journal of Water Resource and Protection》 2009年第5期325-335,共11页
Development pressure has led to serious deforestation on the Indochina Peninsula. Particularly rapid defor-estation has occurred in easily accessible lowland areas, and it is thus important to accumulate knowledge abo... Development pressure has led to serious deforestation on the Indochina Peninsula. Particularly rapid defor-estation has occurred in easily accessible lowland areas, and it is thus important to accumulate knowledge about these forests immediately. We measured evapotranspiration rates for a lowland dry evergreen forest in Kampong Thom Province, central Cambodia, using the energy balance Bowen ratio (EBBR) method based on meteorological data collected from a 60-m-high observation tower. Daily evapotranspiration was higher during the dry season than during the rainy season of the Asian monsoon climate. The seasonal variation in evapotranspiration generally corresponded to the seasonal difference in the vapor pressure deficit. A multi-layer model was used to simulate the seasonal variation in evapotranspiration. The multilayer model also reproduced the larger evapotranspiration rate in the dry season than in the rainy season. However, observed values substantially exceeded model-calculated results during certain periods at the beginning of the dry season and in the late dry season. Moreover, during the rainy season, the model tended to overestimate evapotranspiration. The differences between these observed and simulated values may have been caused by seasonal characteristics of photosynthesis and transpiration in the lowland dry evergreen forest that were not considered in the model simulation. 展开更多
关键词 Cambodia Energy balance BOWEN ratio Method EVAPOTRANSPIratioN LOWLAND DRY EVERGREEN Forest Multilayered Model
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Determination of the Stable Slope Configuration of Oval-Shaped Furrow Pits
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作者 朱乃龙 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2004年第1期86-88,共3页
The space effects of oval-shaped furrow pit slopes were analyzed by the elastic mechanics principle.The interaction of limit equilibrium slope angle,friction coefficient,cohesion and horizontal radius of oval-shaped f... The space effects of oval-shaped furrow pit slopes were analyzed by the elastic mechanics principle.The interaction of limit equilibrium slope angle,friction coefficient,cohesion and horizontal radius of oval-shaped furrow pits has been derived.The oval trumpet-like rock mass is homogeneous and elastic while only loaded by its dead weight.The interaction indicates that the deeper an oval-shaped furrow pit is excavated,the greater the limit equilibrium slope angle.Both the theory base for reducing stripping waste rock in an oval-shaped furrow pit and the basic way to determine the configuration of a stable slope were developed from the mentioned interaction.The theory includes the preceding principles of stability analysis of slopes.Compared with the configuration determined by traditional theory of slope stability,a great quantity of stripping waste rock can be reduced by that determined in this paper under stable conditions. 展开更多
关键词 elastic mechanics oval-shaped furrow pit slope stability limit equilibrium angle ratio of stripping-to-ore
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LOW-COMPLEXITY JOINT BEAMFORMING AND POWER ALLOCA-TION FOR SINR BALANCING IN COGNITIVE RADIO NETWORKS
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作者 Yang Yang Wang Jinlong Wu Qihui Liu Xin 《Journal of Electronics(China)》 2010年第5期686-695,共10页
We consider the Signal-to-Interference plus Noise Ratio(SINR) balancing problem in-volving joint beamfoming and power allocation in the Cognitive Radio(CR) network,wherein the Single-Input Multi-Output Multiple Access... We consider the Signal-to-Interference plus Noise Ratio(SINR) balancing problem in-volving joint beamfoming and power allocation in the Cognitive Radio(CR) network,wherein the Single-Input Multi-Output Multiple Access Channels(SIMO-MAC) are assumed.Subject to two sets of constraints:the interference temperature constraints of Primary Users(PUs) and the peak power constraints of Cognitive Users(CUs),a low-complexity joint beamforming and power allocation algo-rithm called Semi-Decoupled Multi-Constraint Power Allocation with Constraints Preselection(SDMCPA-CP) for SINR balancing is proposed.Compared with the existing algorithm,the proposed SDMCPA-CP can reduce the number of matrix inversions and matrix eigen decompositions signifi-cantly,especially when large numbers of PUs and CUs are active,while still providing the optimal balanced SINR level for all the CUs. 展开更多
关键词 Cognitive Radio (CR) BEAMFORMING Power allocation Signal-to-Interference plus Noise ratio (SINR) balancing
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A New Method for the Dynamic Reserves of Gas Condensate Reservoir Using Cyclic Gas Injection Based on the Effects of Reinjection Ratio and Water Influx
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作者 Yu Xiong Ling Wang +1 位作者 Zhongqian Zhu Wei Xie 《Engineering(科研)》 2015年第7期455-461,共7页
As we all know, cyclic gas injection is one of the most effective development methods to improve condensate oil recovery. When dealing with the calculation of the reserves, the injection-production differences and wat... As we all know, cyclic gas injection is one of the most effective development methods to improve condensate oil recovery. When dealing with the calculation of the reserves, the injection-production differences and water influx create great influence on the accuracy. Based on the existing research, we proposed a new material balance equation which considered the differences of composition between produced and injected fluids and the effect of water influx, and a solution was provided in this paper. The results of the method are closer to the actual situation because they are built on the law of conservation of mass, and the using of curve fitting method can not only avoid the use of water influx coefficient but also obtain the water influx rate and reserves at the same time. The YH-23 gas condensate reservoir is taking as a typical subject to do the research, which has been exploited by cycle gas injection for 14 years. Three different methods are used to calculate the reserves, and the results show that the method proposed in this paper has minimum error of 2.96%. 展开更多
关键词 CONDENSATE GAS Reservoir Cyclic GAS Injection Dynamic RESERVES Material balance Method REINJECTION ratio Water INFLUX
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基于冲能吸能平衡效应的冲击地压巷道分级支护研究 被引量:3
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作者 高明仕 俞鑫 +2 位作者 徐东 贺永亮 赵世帆 《岩土力学》 EI CAS CSCD 北大核心 2024年第1期38-48,共11页
冲击地压是煤炭开采过程中发生的一种动力灾害,主要是由积聚在煤岩中的弹性变形能突然急剧释放造成的,约90%发生在巷道中。巷道冲击破坏不仅与冲击能量直接相关,还与冲击距离远近紧密相关,提出能距比的概念,即冲击震源释放能量与其至巷... 冲击地压是煤炭开采过程中发生的一种动力灾害,主要是由积聚在煤岩中的弹性变形能突然急剧释放造成的,约90%发生在巷道中。巷道冲击破坏不仅与冲击能量直接相关,还与冲击距离远近紧密相关,提出能距比的概念,即冲击震源释放能量与其至巷道距离的比值。根据冲击地压动静载叠加机制和冲能吸能平衡理论,综合考虑冲击震源能距比量级、巷道破坏程度、支护构件吸能、弱结构吸能等特性,建立了巷道围岩冲击矿震稳定性控制模型,分析了冲能、吸能的构成和计算过程,搭建了冲击地压能级与巷道支护强度之间的对应关系,确定了“四高锚网+”为主导技术的煤矿巷道防冲抗震支护体系。根据能距比量级大小,将冲击地压巷道支护安全可靠性分为P1~P4级别,分级对应采取不同支护强度的“四高锚网+”组合支护技术。“四高”锚网支护可对应能距比为102量级的无冲击巷道,“四高锚网+1”(O型钢棚、吸能防冲单元架、围岩弱结构)对应能距比为103量级的冲击地压,“四高锚网+2”对应能距比为104量级的冲击地压,“四高锚网+3”对应能距比为105量级的冲击地压,106及以上量级的冲击危险必须停产、撤人远场处理。结合工程实例进行了巷道防冲支护方案和参数设计,初步验证了理论研究成果的可行性和实用性。研究成果可为我国煤矿冲击地压巷道支护理论研究和工程实践提供一定的参考指导。 展开更多
关键词 冲击地压 巷道围岩控制 冲能吸能平衡 能距比 分级支护
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高地层倾角油藏高低部位油井液量配比研究
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作者 王群一 马晓丽 +3 位作者 蒋明洁 李丹 毕永斌 顾潇 《科学技术与工程》 北大核心 2024年第2期538-544,共7页
在高倾角断块油藏中,受重力作用影响,高、低部位油井开发效果差异大。运用物理模拟实验分析了地层倾角对高、低部位油井开发效果的影响,推导了考虑均衡驱替的水驱断块倾角油藏高、低部位油井产液量配比计算方法,并通过与数值模拟结果对... 在高倾角断块油藏中,受重力作用影响,高、低部位油井开发效果差异大。运用物理模拟实验分析了地层倾角对高、低部位油井开发效果的影响,推导了考虑均衡驱替的水驱断块倾角油藏高、低部位油井产液量配比计算方法,并通过与数值模拟结果对比,验证了油井产液量配比计算方法的准确性。研究发现:随着储层倾角的增加,高部位流线变少、水驱波及区域变小、采出程度变低。随着储层倾角增加,达到均衡动用所需的油井产液量配比(高部位油井产液量与低部位油井产液量比)增加。在相同储层倾角的情况下,随着原油密度和注水强度增加,倾角对达到均衡驱替所需的油井产液量配比的影响变弱,油井产液量配比降低。该研究对高倾角断块油藏均衡开发具有指导意义。 展开更多
关键词 高地层倾角 断块油藏 均衡驱替 产液量配比 物理模拟
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基于水库旱限水位的大型灌区水资源空间均衡优化调控
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作者 张礼兵 焦丽萍 +3 位作者 金菊良 陈小凤 章启兵 康传宇 《水利学报》 EI CSCD 北大核心 2024年第10期1187-1198,共12页
由于自然地理特征和经济社会活动的差异,大型灌区水资源分布和利用在时空上是不平衡的,尤其是受水文气象波动影响的农业灌溉供水,需要借助水利工程进行水资源空间均衡调控。目前按典型水平年制订的常规调配水方案无法展现水资源空间均... 由于自然地理特征和经济社会活动的差异,大型灌区水资源分布和利用在时空上是不平衡的,尤其是受水文气象波动影响的农业灌溉供水,需要借助水利工程进行水资源空间均衡调控。目前按典型水平年制订的常规调配水方案无法展现水资源空间均衡状态在年内的变化响应过程,也无法考虑水资源在年际间调配的需求。鉴此,本文基于灌区水资源系统空间均衡评价模型和半分布式水资源系统模拟模型,以干旱年缺水时段平均水资源系统空间均衡度最大为目标,以骨干水库分期分级旱限水位和灌区分单元分用水户限供比例为调控变量,运用遗传算法开展大型灌区水资源系统空间均衡优化调控研究。淠河灌区应用结果显示:骨干水库的分级分期旱限水位能够实现水资源在年内和年际时间上的均衡调节,而分单元分用水户的限制供水措施能够使水资源在空间上得到合理配置。二者共同作用能更好地协调灌区供需水在时程分布和空间均衡间的关系,相较于运行现状能大幅提升水资源系统空间均衡度,增强灌区的可持续发展能力,为基于旱限水位的复杂水资源系统管理和应用提供新的思路。 展开更多
关键词 水资源 大型灌区 空间均衡 旱限水位 限供比例 优化调控
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沿江典型区域杨树大径材人工林复合经营技术研究
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作者 刘俊龙 吴中能 +5 位作者 苗婷婷 丁昌俊 苏晓华 孙慧 闫彩霞 杨传宝 《安徽林业科技》 2024年第3期20-24,共5页
本文对杨树大径材培育周期内的5个典型复合经营模式生长和经济效益进行分析,选择出适宜长江沿江典型区域种植的杨树大径材复合经营模式。结果表明:参试林农复合经营模式下杨树的胸径、树高、单位面积蓄积量分别比纯林增加15.31%(YM)~20.... 本文对杨树大径材培育周期内的5个典型复合经营模式生长和经济效益进行分析,选择出适宜长江沿江典型区域种植的杨树大径材复合经营模式。结果表明:参试林农复合经营模式下杨树的胸径、树高、单位面积蓄积量分别比纯林增加15.31%(YM)~20.92%(YYD)、9.52%(YM)~11.31%(YY)、45.66%(YM)~61.38%(YYD)。采用间作模式的6年生杨树复合经营总收益均大于杨树纯林,杨树间作模式的总产值为杨树纯林的2.78(YM)~4.47倍(YYD)。采用多作物间作模式总收益及总产值明显高于单作物间作模式。其中套种6年杨树-油菜-黄豆(YYD)模式累计总收益(11 905元/667m^(2))最高,杨树-小麦-黄豆(YMD)累计总收益(11 599元/667m^(2))次之。5个模式下6年生杨树木材收益由高到低依次为:YYD(7 244元/667m^(2))>YMD(7 197元/667m^(2))>YY(7 106.5元/667m^(2))>YM(6 539.6元/667m^(2))>YC(4 408.48元/667 m^(2))。杨树-油菜-黄豆(YYD)是促进大径材杨树生长、材积和经济效益最高的优选模式。此研究旨在为长江沿江典型区域杨树的大径材培育和复合经营策略提供参考。 展开更多
关键词 沿江地区 杨树大径材 林农复合经营 产投比 收支平衡
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科尔沁沙地沙丘生态系统水热通量特征及影响驱动因子 被引量:2
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作者 张思敏 郝丽娜 +5 位作者 童新 贾天宇 张亦然 马扩 伦硕 刘廷玺 《中国环境科学》 EI CAS CSCD 北大核心 2024年第2期1041-1052,共12页
以科尔沁沙地的典型沙丘区为研究对象,利用涡动相关系统(EC)持续监测沙丘生态系统2013~2022年的表面能量通量数据,采用普通最小二乘线性回归法(OLS)和表面能量平衡比率(EBR)两个指标评估能量平衡闭合度,对沙丘生态系统生长季(4~10月)能... 以科尔沁沙地的典型沙丘区为研究对象,利用涡动相关系统(EC)持续监测沙丘生态系统2013~2022年的表面能量通量数据,采用普通最小二乘线性回归法(OLS)和表面能量平衡比率(EBR)两个指标评估能量平衡闭合度,对沙丘生态系统生长季(4~10月)能量通量的日变化、季节变化以及年际变化进行分析,并计算波文比(β)和能量平衡比,探讨了影响潜热通量(LE)、感热通量(H)和土壤热通量(G)变化的环境因素.结果表明:多年平均年净辐射(R_(g))为1592.77MJ/m^(2),其中H、LE和G分别为614.60,636.22和117.76MJ/m^(2),科尔沁沙地沙丘生态系统年能量的主要组成部分为潜热通量,占总能量的40%.β日动态曲线呈单峰变化,波动相对较平缓.各年年均表面能量平衡比率(EBR)介于0.75~0.90之间,多年年均EBR为0.87,说明能量平衡闭合度的残差为13%.研究表明饱和水汽压差(VPD)是影响能量通量的主要因素,其次是空气温度(T_a)和土壤温度(T_s),均与能量通量呈显著正相关;而植被对能量通量的影响表现在LE与叶面积指数(LAI)呈正相关,而H相反. 展开更多
关键词 科尔沁沙地 涡动相关系统 水热通量 波文比 能量平衡比 影响因素
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断控型碳酸盐岩油藏动态储量计算方法 被引量:2
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作者 耿洁 乐平 +3 位作者 杨文明 杨博 赵彬 张如杰 《新疆石油地质》 CAS CSCD 北大核心 2024年第4期499-504,共6页
断控型碳酸盐岩油藏非均质性强,不同尺寸的孔、缝、洞交错发育,采用一般物质平衡方法计算的动态储量可能大于静态储量。在引入水油比的基础上,考虑孔缝洞介质不同时的岩石压缩系数,得到了适用于断控型油藏的综合压缩系数,并在此基础上... 断控型碳酸盐岩油藏非均质性强,不同尺寸的孔、缝、洞交错发育,采用一般物质平衡方法计算的动态储量可能大于静态储量。在引入水油比的基础上,考虑孔缝洞介质不同时的岩石压缩系数,得到了适用于断控型油藏的综合压缩系数,并在此基础上建立了断溶体流动物质平衡新方程,通过数值模拟,验证了新方程的准确性与适用性。结果表明:新方程计算的动态储量与数值模拟得到的静态储量误差仅为0.1099%,验证了新方程准确可靠;哈拉哈塘地区多口井用新方程计算的动态储量与地质建模雕刻的静态储量相对误差为-4.82%~-0.15%,远远低于物质平衡方程计算的动态储量与静态储量的相对误差,新方程计算结果更接近实际情况,更适用于哈拉哈塘地区断控型碳酸盐岩油藏的储量计算。 展开更多
关键词 断控型油藏 碳酸盐岩 水油比 岩石压缩系数 流动物质平衡 动态储量
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大展弦比板弯扭耦合受迫振动分析
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作者 王卓 毛晓晔 +1 位作者 丁虎 陈立群 《动力学与控制学报》 2024年第1期27-36,共10页
对于工程广泛存在的大展弦比结构,首次研究了大展弦比板弯扭耦合受迫振动响应.考虑弦向相对弯曲刚度远大于展向弯曲刚度,将弦向截面等效为刚体,考虑其绕展向轴线的扭转,应用Hamilton原理分别计算大展弦比板的势能与动能,建立两端简支的... 对于工程广泛存在的大展弦比结构,首次研究了大展弦比板弯扭耦合受迫振动响应.考虑弦向相对弯曲刚度远大于展向弯曲刚度,将弦向截面等效为刚体,考虑其绕展向轴线的扭转,应用Hamilton原理分别计算大展弦比板的势能与动能,建立两端简支的大展弦比板弯扭耦合受迫振动的动力学控制方程.将动力学控制方程进行Galerkin截断后,通过谐波平衡法和微分求积法/微分求积单元法,计算得到了大展弦比模型弯扭耦合受迫振动稳态响应的解析解及数值解,同时验证了解的截断收敛性及谐波收敛性.最后研究了外激励幅值对结构受迫振动响应的影响.结果将为工程中广泛存在的大展弦比结构设计提供指导. 展开更多
关键词 大展弦比板 弯扭耦合振动 受迫振动 谐波平衡法
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