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This article provides an overview of the Kivcet technique in Jiangxi Copper Corporation, reviews the production status and problems encountered in the past decade, introduces its technological advantages and prospect. It is believed that the Kivcet process has advantages such as strong adaptability to raw materials, stable operation, high metal recovery rate, and low cost of zinc leaching residue treatment, which is the vitality of lead-zinc smelting enterprises in the future.

At the experimental base of Tianjin Agricultural University, the infiltration process of water was measured by double - ring infiltration instrument at six points. Horton，Philip and Kostiakov-lewis (K-l) infiltration models were fitted with the infiltration data measured and the parameters were correspondingly obtained. Six sets of parameters of the corresponding infiltration model were obtained, and six sets of parameters were used for statistical analysis. The reasonable number of points of the corresponding model was obtained. Then, the statistical analysis of the cumulative infiltration amount was used to obtain the variation of the number of reasonable points in the three models with time. The results show that the imitative effect of accumulative infiltration water and time in K-l model is the best, and the curve of reasonable test points determined by K-l model with time is located under the other two models; The reasonable number of points determined by the parameter K in the K-l model is the least and most reasonable. In view of this, the number of reasonable points was determined by using the parameter K in the K-l model.

【Objective】 To reverse the continued decline of dwindling water resources in northern China, most regions have proposed to restrict groundwater extraction for irrigation. Optimizing irrigation timing and making most of natural precipitation and irrigation water is essential to minimizing crop yield loss due to the reduced irrigation amount. The purpose of this paper is to study the optimization of timing of maize irrigation. 【Method】 Models relating maize yield and water usage were established based on crop growth model and soil water-heat coupling model. The model parameters were determined based on data measured from 2017—2020 from a maize field at Wenyuhe Experiment Station in Shanxi province. Meteorological data measured from 1957—2018 at the station was used in the frequency analysis for determining the irrigation amount by dividing the frequency from 5% to 95%. We optimized the timing of the irrigation assuming that the irrigation amount varied from 45 to 105 mm, and the times of irrigation varied from 1 to 5. The K-M model was used to determine the relationship between cumulative evapotranspiration and cumulative precipitation between two adjacent irrigations. Using the meteorological data measured from 2009 to 2018, the model was applied to optimize the irrigation timing, from which we compared the yield-increasing benefits obtained from the K-M method, the dynamic irrigation water limit method, and the empirical irrigation method. 【Result】 The correlation coefficient between the cumulative evapotranspiration and the cumulative effective precipitation under different irrigation amount was greater than 0.92. With the increase in irrigation amount, the parameter M in the K-M method, which characterizes the irrigation amount, increased. 【Conclusion】 Evaluation of the three methods for determining the optimal irrigation timing based on yield, benefit and water use efficiency showed that, compared with the empirical irrigation method, the K-M method was the best, followed by the dynamic irrigation water limit method.

【Objective】 Evapotranspiration is important not only as a component of the hydrological cycle but also for its role in modulating crop growth. The purpose of this paper is to measure the evapotranspiration of spring maize using weighing lysimeters and analyze its relationship with the yield and water use efficiency of the crop. 【Method】 A two-year experiment was conducted in Shanxi province from 2019 to 2020, and the evapotranspiration of spring maize under different water supplies was measured using weighing lysimeters. We compared four irrigation schedules: irrigating 5 times (T1), 6 times (T2), 4 times (T3) and 2 times (T4), with irrigation amount in all them being kept at 60cm. The irrigations differed only in the criteria set to resume irrigation, judged by a critical soil moisture measured in situ. Hourly changes in soil water content in all lysimeters were recorded automatically, and daily evapotranspiration was calculated using the water balance method, from which we further analyzed the relationship between yield and evapotranspiration. 【Result】 The evapotranspiration rate peaked in the middle of growing season in all treatments, and the daily evapotranspiration rate in all growing stages increased with the irrigation amount. In T2, the maximum evapotranspiration rate was 0.44 mm/h occurring at 13:00 pm, while in T4 it was reduced to 0.175 mm/h occurring at 09:00 am. The legacy of the effect of irrigation scheduling on evapotranspiration lasted a few days following the irrigation. The more frequently the crop was irrigation, the more the water would be evaporated or transpired. Most soil water was lost via evapotranspiration in the middle growth stage, i.e., 52 to 120 days after drilling the seeds; the maximum daily evapotranspiration during this period was 10.68 mm/d in 2019 and 7.27 mm/d in 2020, accounting for 75.7% and 72.9% of the total evapotranspiration in each of the two years, respectively. Model using relative evapotranspiration to predict the crop yield gave a good fitting with a correlation coefficient R2 > 0.99. Further verification of the model against data measured from 2018 to 2020 from a spring maize field in Wenyu River Basin proved the robustness of the model with a correlation coefficient R2 >0.94. 【Conclusion】 Evapotranspiration measured from the weighting lysimeter was accurate and can be used to predict yield and estimate soil water change.

Over-immunosuppressed kidney transplant recipients are susceptible to malignancies and BK polyomavirus (BKPyV)-associated nephropathy (BKPyVAN). This study aimed to verify the association between BKPyV infection and urinary tract cancers (UTC). A total of 244 kidney transplant recipients were enrolled at Chang Gung Memorial Hospital from June 2000 to February 2020. Biopsy-proven BKPyVAN patients (n = 17) had worse kidney function (eGFR: 26 ± 13.7 vs. 47.8 ± 31.0 mL/min/1.73 m2). The 5-year allograft survival rates for patients with and without BKPyVAN were 67% and 93%, respectively (p = 0.0002), while the 10-year patient survival was not different between the two groups. BKPyVAN patients had a significantly higher incidence of UTC compared to the non-BKPyVAN group (29.4% vs. 6.6%). Kaplan–Meier analysis showed that the UTC-free survival rate was significantly lower in BKPyVAN patients, and the onset of UTC was significantly shorter in BKPyVAN patients (53.4 vs. 108.9 months). The multivariate logistic regression analysis demonstrated that age (RR = 1.062) and BKVAN (RR = 6.459) were the most significant risk factors for the development of UTC. Our study demonstrates that BKPyVAN patients have greater allograft losses, higher incidence, a lower cancer-free survival rate, and an earlier onset with a higher relative risk of developing UTC compared to non-BKPyVAN patients.

【目的】分析春玉米蒸散变化规律及建立产量与水分的关系，为山西省春玉米灌溉需水量的精准调控提供依据。【方法】利用山西省中心灌溉试验站称重式蒸渗仪在2019—2020年春玉米不同供水量条件下的蒸散发测定试验，共设置4个处理，分别为T1（5水）、T2（6水）、T3（4水）、T4处理（2水），按照作物需水量确定灌水时间，灌水定额均为60 mm，每个处理配置1套称重式蒸渗仪，自动记录逐时土体水质量。利用水量平衡方法计算逐日蒸散量，分析蒸散变化规律，并利用相对腾发量为自变量的过程模型，建立产量与蒸散量之间的关系。【结果】发育中期日蒸散强度较其他生育阶段蒸散强度大，受灌水的影响，灌溉定额越大，不同生育阶段的日蒸散强度普遍增大，T2处理发育中期，13:00蒸散量最大为0.44 mm/h，T4处理发育中期09:00蒸散量最大为0.175 mm/h；灌水也会影响灌后几日蒸散量，灌水越多，蒸散量也越多，累计蒸散量也越大。春玉米生育期内蒸散作用主要集中在发育中期（播后的52~120 d），该时期日最大蒸散量，2019年和2020年分别为10.68 mm/d和7.27 mm/d，相应的蒸散量占全生育期蒸散量比例分别为75.7%和72.9%。以相对腾发量为自变量的过程模型对产量进行了模拟，率定了模型参数，拟合效果很好，相关系数（R2）达到0.99以上，并利用文峪河2018—2020年春玉米的测试资料进行模型参数验证，R2达到0.94以上，表明率定的参数合理。【结论】基于蒸渗仪测定数据能更准确地确定产量与水分关系，此外，利用FAO推荐的作物系数法计算的蒸散量很好地反映了作物的潜在蒸散量。

【目的】充分发挥自然降水的生产力，最大限度提高有限灌溉水资源利用效率，研究灌溉预报中确定灌水时间的方法。【方法】基于作物生长模型和土壤水热动态模拟模型，建立了玉米产量与水分关系模型，利用山西省文峪河试验站2017—2020年玉米生长季试验资料，通过最小二乘法确定了模型参数。并利用该站1957—2018年气象资料以灌溉需水量从小到大的顺序做频率分析，确定了5个典型年（分别对应5%、25%、50%、75%和95%这5个频率）；针对不同的灌水定额（45、75 mm和105 mm）和灌水次数（1、2、3、4次和5次）组合，优化确定了相应的灌水时间，以累计有效降水量为自变量，以考虑可供水量修正的累计蒸散量为因变量，分析构建了相邻2次灌水期间累计蒸散量和累计有效降水量的关系，基于该关系提出了确定灌水时间的K-M法；在此基础上，利用2009—2018年的气象资料，通过模拟分析比较了3种方法（K-M法、动态灌水下限法和经验灌水法）的增产效益。【结果】结果表明，不同灌水定额下，累计蒸散量和累计有效降水量关系的相关系数均能达到0.92以上，表明该模型在年际间和不同灌水定额之间均有较好的适用性；随着灌水定额的增大，K-M法中参数M呈增大的趋势，表明参数M一定程度上具有灌水定额的物理特性。【结论】基于产量、效益和用水效率3方面对3种确定灌水时间方法的评价表明，与经验灌水法相比，以K-M法最好，动态灌水下限法次之。

【目的】检验温度、水分、盐分三参数传感器（SMEC 300）测定土壤含水率、电导率的精度。【方法】在天津农学院西校区农田水循环试验基地进行了土壤含水率与电导率的率定试验。试验设置3种供水水平（2.65、3.25、3.80 kg）和4种盐分水平（加盐量0、20、70、100 g）以及6种矿化度梯度（1、5、10、15、20、25 g/L）。布置6个盆，每盆内干土质量为8.85 kg，土层厚度为10 cm，传感器埋置于土面下5 cm处，试验期间定期称取盆的质量，由此测得土壤实际含水率；电导率率定试验也布置6个盆，盆内加水8 L/盆，盆内放置4个传感器，每40 min测试1个处理，利用数据采集仪获取传感器数据。分别对土壤含水率和电导率进行率定。【结果】传感器测定的电导率与矿化度呈显著的指数关系，相关系数均在0.92以上；土壤盐分影响土壤含水率的率定，实际含水率与传感器测定的土壤含水率和电导率呈二元线性关系，相关系数最大为0.940 4，最小为0.601 9，均达到了显著或极显著水平，不同传感器的率定参数有较大差异。【结论】电容式土壤温度、水分、盐分三参数传感器有其对应的参数，应逐个传感器进行率定。