Jiamusi City Research Articles

Agricultural Multi-Water Source Allocation Model Based on Interval Two-Stage Stochastic Robust Programming under Uncertainty

Numerous uncertainties and complexities exist in the agricultural irrigation water allocation system, that must be considered in the optimization of water resources allocation. In this paper, an agricultural multi-water source allocation model, consisting of stochastic robust programming and two-stage random programming and introducing interval numbers and random variables to represent the uncertainties, was proposed for the optimization of irrigation water allocation in Jiamusi City of Heilongjiang Province, China. The model could optimize the water allocaton to different crops of groundwater and surface water. Then, the optimal target value and the optimal water allocation of different water sources distributed to different crops could be obtained. The model optimized the economic benefits and stability of the agricultural irrigation water allocation system via the introduction of a the penalty cost variable measurement to the objective function. The results revealed that the total water shortage changed from [18.6, 32.3] × 108 m3 to [15.7, 26.2] × 108 m3 at a risk level ω from zero to five, indicating that the water shortage decreased and the reliability improved in the agricultural irrigation water allocation system. Additionally, the net economic benefits of irrigation changed from [287.21, 357.86] × 108 yuan to [253.23, 301.32] × 108 yuan, indicating that the economic benefit difference was reduced. Therefore, the model can be used by decision makers to develop appropriate water distribution schemes based on the rational consideration of the economic benefit, stability and risk of the agricultural irrigation water allocation system.

A hospital based prospective survey of perinatal depression in Chinese women of Jiamusi city

Abstract Objectives: To evaluate whether an antenatal and immediate postpartum Edinburgh Postnatal Depression Scale score are predictive of future postpartum depression and observe the correlation in-between the scores

Individual Tree Growth Model of Larch Plantation based on Crown Competition Factors

Based on the re-measured data between 2007- 2009 from 14 permanent sample plots in larch plantations located in Mengjiagang Forest Farm,Jiamusi city of Heilongjiang province,the relationship between crown variables and increment of tree was analyzed and the distance-dependent individual tree growth model for larch plantation was developed by introducing two crown competition factors( CIaand CIb) as new competition index in this paper. The results showed that two crown competition factors( CIaand CIb) are better than the Hegyi competition index( CI). The correlation between various competition index with basal area increment of individual tree is CIb CIa CI for larch plantation. With enlargement of the competition influence zone of object tree,the competition index tends to be stable and the model fitting effect increases. Tee size is the main affecting factor for the individual tree growth for larch plantation. The basal area increment of individual tree increases as tree diameter at breast height increasing. The goodness of fit for individual tree growth model was improved 5. 6% by introducing new distance-dependent crown competition index. The distance-dependent individual tree growth model developed in this paper can be suitable for predicting basal area increment of individual tree for larch plantation.

黑龙江省20世纪森林变化及对氧气释放量的影响

随着对大气环境质量研究的深入，大气中氧气含量变化也引起了关注。森林是固碳释氧的重要生态系统，黑龙江省近百年来，森林面积减少了37.163%，估算由此导致的森林氧气释放量变化，对研究大气氧气含量变化具有重要意义。以黑龙江省1900年、1949年、1986年和2009年为时间断面，采用C-FIX模型及碳氧平衡方法，模拟并分析了20世纪黑龙江省森林氧气释放量及其变化。结果表明：（1）黑龙江省20世纪森林面积减少了106667.570 km²，森林覆盖率减少了23.568%。除樟子松（<em>Pinus sylvestris </em>var.<em> mongolica</em>）林、针阔混交林面积有所增加外，其它树种的森林面积均减少，其中云冷杉（<em>Picea asperata </em>and<em> Abies nephrolepis</em>）林及红松（<em>Pinus koraiensis</em>）林面积减少超过80%，空间上以松嫩平原及三江平原减少最为显著；（2）森林年氧气释放量百年来减少了5621.560万t，减少近三分之一，其空间变化明显，西南部森林氧气释放量由百年前的最高区域变为最低区域，三江平原释放氧气的森林区域明显减少；（3）百年来各行政区森林年氧气释放量除伊春微弱增加外，其余均呈减少趋势。其中大庆市、齐齐哈尔市减少显著，减少了90%以上；（4）控制实验表明，森林面积变化导致黑龙江省区域森林年氧气释放量减少了50%。人类活动引起的森林面积减少，是导致黑龙江省森林氧气释放量减少的主要因素。;Through recent extensive studies on air quality, researchers have paid more attention to changes in oxygen content in the atmosphere. Studies show atmospheric oxygen in the lower atmosphere has a slow diminishing trend. The forest ecosystem is an important source of carbon sequestration and oxygen release, so, oxygen content is directly impacted by the change of forest area. Therefore, it is essential to examine the deforestation process and evaluate its impact on the changes of oxygen content in the atmosphere. Heilongjiang Province is the area in China primarily focused on forest resources and coverage, however, during the past century approximately 37.163% of the forest area has been converted to other land uses. We selected Heilongjiang Province as the research area, as it provided greater significance to study the variation of oxygen content in the atmosphere due to the estimated change of oxygen release caused by deforestation. According to historical references and remote sensing image data, we rebuilt the forest spatial distribution of Heilongjiang Province in 1900, 1949, 1986 and 2009. Using the C-FIX Model and carbon-oxygen balance method, this research simulated and analyzed the quantity and changes of oxygen released by the forest ecosystemof Heilongjiang Province.Analyses of the results suggest four major conclusions. First, the forest area of Heilongjiang has decreased by 106667.570 km², or approximately 23.568% during the last century (1900-2009). Except for <em>Pinussylvestris </em>var.<em> mongolica </em>forest and Coniferous and broad leaved mixed forest, the geographic areas of all other forest types have decreased, within which the areas of <em>Piceaasperata</em> and <em>Abiesnephrolepis </em>forest and <em>Pinuskoraiensis</em> forest have decreased by more than 80%.Spatially, significant forest loss can be found in the Songnen and Sanjiang Plains. Second, during the last century, the quantity of oxygen released has been reduced by 56.2156 million tons, or approximately one-third of that in 1900. The oxygen production in the Southwest was the highest in 1900, but became the area with the lowest production in 2009. Moreover, a significant decrease of forest oxygen production occurred in the Sanjiang Plain. Third, the quantity of oxygen released from almost all administrative regions of Heilongjiang presents a decreasing trend, with the exception of Yichun. Among these regions, the quantity of oxygen released has reduced more than 90% in Daqing City and Qiqihar City; over 50% in Jiamusi City, Suihua City, and Jixi City; over 25% in Shuangyashan City, Qitaihe City and Heihe City; less than 10% in Daxinganling Region and Mudanjiang City. Fourth, during the past century,the total amount of oxygen released by <em>Picea asperata</em>and <em>Abies nephrolepis</em> forest has reduced by 91.855%, 78.905% by <em>Pinuskoraiensis</em> forest, and by 25.043% and 23.936% by deciduous mixed forest and <em>Larixgmelini</em> forest, respectively. However, the total amounts of oxygen released by Coniferous and broad leaved mixed forest and <em>Pinus sylvestris var. mongolica</em> forest increased by 20.356% and 48.209%,respectively. <em>Piceaasperata</em>and <em>Pinus koraiensis</em> forest released the most amount of oxygen per unit area; <em>Larixgmelini</em> forest and <em>Pinus sylvestris var. mongolica</em> forest released less. Finally, the results of the control experiments suggest that forest oxygen production in Heilongjiang is only approximately half of the amount in 1900.Moreover, forest degradationdue to human activities is one of the major factors that leads to the decrease of the quantity of oxygen released.

Monitoring of External Prestressing Tendons Construction Process of Jiamusi Highway Prestressed Concrete Bridge during Strengthening in China

Jiamusi highway prestressed concrete bridge is located in the Jiamusi City within Heilongjiang province in the east north of China. The strengthening and repairing of the bridge structure can be provided an effective and economic solution in appropriate situation. The objective of this study are to monitor the construction process of external prestressing tendons for strengthening of Jiamusi highway prestressed concrete bridge. Monitoring process includes measurement of external prestressing tendons natural frequency, monitoring of tensile forces values of external prestressing tendons, monitoring of development of anchor beams cracks, and monitoring of anchor beam deformation. The results of monitoring process show that the box girder No. 11 has the largest values of proportional coefficient (K) and the maximum value is 327.8. Box girder No. 8 has the largest values of frequency, the maximum value is 3.499. Five levels of tension are used in the application of tensile force in the tension process of external prestressing tendons. These levels are level 1=248.2kN, level 2=496.4kN, level 3=744.6kN, level 4=992.8kN, and level 5=1241kN. The measured tendons elongation values of left box girder No.8 are more than the theoretical values. For left and right box girder No. 9, side external tendons of left box No. 10, and left and right box girder No. 11, the measured values are less than theoretical values of elongation. After tension process, there are no new cracks in the top, web, and bottom of anchor beam and a small number of cracks developed slightly. These cracks are found around ducts of external tendons. The length of cracks rang from 0.03m to 0.5m and width rang from 0.05 mm and 0.25mm. The longitudinal deformation of the interface and top of anchor beam is very small, ranging from 0.001mm to0.115mm, which averaged 0.026mm. The overall state of anchor beams and box girders during strengthening is good.