Recharge and loss of groundwater during freezing-thawing period in inland basin, Northwestern China

天山北麓平原区,每年冻结过程的时间远大于融化过程。在昌吉地下水均衡试验场,选择该平原的3种代表性土壤(粉质轻粘土、细砂、砂砾石),利用地中渗透仪观测冻结冻融期的地下水补给与损耗。根据不同岩性的地下水蒸发极限深度,设计了不同的地下水埋深。在冻结期,砂砾石、细砂岩性分布地区有利于浅埋型地下水资源的保护。在冻融期,无论何种地下水埋深水平,3种岩性的地下水都获得冻融水的补给,但细颗粒岩性的补给量相对较少且存在滞后效应,相反,粗颗粒岩性更有利于地下水资源的形成。冻结期一个月的地下水最大损耗量不超过25 3mm(砂砾石),而冻融期一个月的地下水最大补给量高达113 3mm(细砂),冻融期是年内地下水的重要补给时期。In the plain located in　the north slope of Tianshan Mountain, early November is the beginning of the freezing period, while　 early March next year is the beginning of the thaw period. And the freezing period is much longer than the thaw period. In the experimentation station of the groundwater balance, located in Changji County, three kinds of soil (stony sand, fine sand and clay), which are local typical soil in the inland basins, are chosen to observe the recharge and the　loss of groundwater in freezing-thaw period. According to the critical depths of groundwater loss, several kinds of groundwater table are designed for all　 kinds　of soil. In the　freezing period, where the stony sand and sand are　distributed, the protection of groundwater resources is favorable. In the　thaw period, no matter what depth of groundwater table, the recharge occurrs for all of the　three, but the recharge of the fine grained soil is relatively less and shows the　delaying effect. Contrarily, the coarse grained soil is more favorable for the formation of groundwater resources. The largest loss of groundwater is not beyond　25.3　mm in　one month during the　 freezing period(for　example, stony sand), and the largest recharge is more than 113.3　mm in　the　 same time during　the　 thaw period(for　example, fine grained sand), so the thaw period is the important period of groundwater recharge each year."九五"国家重点科技攻关资助项目(96 912 01 03S)~

Study on the mechanism of infiltration and evaporation of phreatic groundwater in the planting conditions

在天山北麓昌吉地下水均衡试验场 ,选择具有代表性的作物玉米进行不同埋深条件下的模拟种植试验 ,分析研究种植条件下不同潜水埋深水平的潜水入渗补给量、潜水蒸发损耗量、土壤水储存量和作物耗水量的变化规律。研究成果对于地下水资源和土壤水资源评价以及地下水和土壤水资源的有效调控利用具有重要实用意义In the text station of the groundwater balance, located in the northern slope of Tianshan Mountain, the corn, local typical crop, is chosen to plant for the text under the conditions of the different groundwater level depth. Through the text, the infiltration and evaporation of the phreatic groundwater, the storage of the soil moisture, and the water requirement of crop are observed and analyzed. The experimentation achievements are significant for the groundwater resource evaluation, the soil moisture resources evaluation, as well as controlling and utilizing effectively the groundwater and soil moisture.“九五”国家重点科技攻关项目的部分研究成果 ( 96 912 0 1 0 3S

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies