The Yellow River valley is one of the three largest cotton production areas in China.An experiment was performed in cotton fields of Anyang,China from 2013 to 2014 to investigate the effects of nitrogen(N) application...The Yellow River valley is one of the three largest cotton production areas in China.An experiment was performed in cotton fields of Anyang,China from 2013 to 2014 to investigate the effects of nitrogen(N) application rate and the ratio between basal and topdressing N fertilizer on N balance in a soil-plant system,N use efficiency,and cotton yield.Five N application rates as treatments were applied with the same split application ratio.Half of the N(50% basal fertilizer) was applied at pre-planting and the other half(50% topdressing fertilizer) at the initial flowering stage.These treatments were:zero N(N0,control),90 kg N ha^(-1)(N90(5/5)),180 kg N ha^(-1)(N180(5/5)),270 kg N ha^(-1)(N270(5/5),a reduced N rate),and 360 kg N ha^(-1)(N360(5/5),a conventional N rate).Additional 2 split application ratios as treatments were applied with the same N rate of 270 kg N ha^(-1).The split application ratios between basal N and topdressing N were 30%:70%(N270(3/7)) and 70%:30%(N270(7/3)).Results demonstrated that soil NH_4-N content in the 0–60 cm layer and NO3-N content in the 0–20 cm layer increased with increased N rate at the squaring and boll-opening stages and then decreased to lower levels at the initial flowering and harvest stages.Soil NO_3-N content in the 20–60 cm layer after the initial flowering stage increased with the increase of topdressing N rate.Soil apparent N surplus varied at different growth stages,while the soil apparent N surplus over the entire growth period exhibited a positive relationship at N rates over 180 kg ha^(-1).Seed cotton yield of N270(3/7) was the highest of all treatments.Plant N uptake,N agronomic efficiency,and apparent N recovery efficiency of N270(3/7) were significantly higher than those of N270(5/5) and N270(7/3) in both growing seasons.These suggest both economic and ecological benefits in cotton production in the Yellow River valley could be created,by appropriately reducing total N application rate and increasing the ratio of topdressing to basal N fertilizer at the initial flowering stage.展开更多
Researchers in several disciplines and fields agree that the image establishing has both perceptual and affecfive evaluations. The paper comparatively analyzes the image of landscapes in ancient water towns held by 16...Researchers in several disciplines and fields agree that the image establishing has both perceptual and affecfive evaluations. The paper comparatively analyzes the image of landscapes in ancient water towns held by 1619 tourists after the investigations of Zbouzhuang and Tongli of Jiangsu Province. Based on the elements of the image of urban landscapes, the perceptual/cognitive image of tourist landscapes in water towns is developed including path, node, landmark, important courtyard, district and edge. Particularly the important courtyard plays the great role on the perceptive image of tourists, however, the perceptual/cognitive images of the district and the edge are obviously weak. Meanwhile, the finding showed that the affective images of tourist landscapes in Zhonzhuang differ with those of Tongli by the method of paired comparison. The main reason is that the affective images are influenced by the impressive scenery spots. Furthermore, the commercialization of streets and pollution of rivers are easy to be functioned negatively.展开更多
In groundwater hydrology,aquitard heterogeneity is often less considered compared to aquifers,despite its significant impact on groundwater hydraulics and groundwater resources evaluation.A semi-analytical solution is...In groundwater hydrology,aquitard heterogeneity is often less considered compared to aquifers,despite its significant impact on groundwater hydraulics and groundwater resources evaluation.A semi-analytical solution is derived for pumping-induced well hydraulics and groundwater budget with consideration of vertical heterogeneity in aquitard hydraulic conductivity(K)and specific storage(S_(s)).The proposed new solution is innovative in its partitioning of the aquitard into multiple homogeneous sub-layers to enable consideration of various forms of vertically heterogeneous K or S_(s).Two scenarios of analytical investigations are explored:one is the presence of aquitard interlayers with distinct K or S_(s) values,a common field-scale occurrence;another is an exponentially depth-decaying aquitard S_(s),a regional-scale phenomenon supported by statistical analysis.Analytical investigations reveal that a low-K interlayer can significantly increase aquifer drawdown and enhance aquifer/aquitard depletion;a high-S_(s) interlayer can noticeably reduce aquifer drawdown and increase aquitard depletion.Locations of low-K or high-S_(s) interlayers also significantly impact well hydraulics and groundwater budget.In the context of an exponentially depth-decaying aquitard S_(s),a larger decay exponent can enhance aquifer drawdown.When using current models with a vertically homogeneous aquitard,half the sum of the geometric and harmonic means of exponentially depth-decaying aquitard S_(s) should be used to calculate aquitard depletion and unconfined aquifer leakage.展开更多
目的分析2型糖尿病患者血清肿瘤坏死因子受体相关因子3(TRAF3)的表达水平与胰岛功能和胰岛素抵抗(IR)的相关性。方法选取2022年8月至2023年12月收治的148例2型糖尿病患者,根据胰岛素抵抗指数(HOMA-IR)值分为无IR组75例和IR组73例;另选8...目的分析2型糖尿病患者血清肿瘤坏死因子受体相关因子3(TRAF3)的表达水平与胰岛功能和胰岛素抵抗(IR)的相关性。方法选取2022年8月至2023年12月收治的148例2型糖尿病患者,根据胰岛素抵抗指数(HOMA-IR)值分为无IR组75例和IR组73例;另选80例同期体检健康者作为对照组。酶联免疫吸附法测定血清TRAF3的表达水平;Pearson和Spearman法分析血清TRAF3表达水平与空腹胰岛素(FINS)、餐后2 h血糖(2 h PG)、胰岛β细胞功能指数(HOMA-β)、胰岛素敏感指数(ISI)相关性;多元线性回归分析2型糖尿病患者发生IR的影响因素;受试者工作特征(ROC)曲线分析血清TRAF3表达水平对2型糖尿病患者IR的预测价值。结果2型糖尿病患者血清TRAF3水平高于体检健康者,无IR组患者血清TRAF3水平低于IR组(P<0.01)。2型糖尿病患者无IR组和IR组FINS、三酰甘油、低密度脂蛋白胆固醇(LDL-C)、糖化血红蛋白(HbA1c)、空腹血糖(FPG)、2 h PG、HOMA-IR、HOMA-β、ISI比较差异有统计学意义(P<0.05,P<0.01);2型糖尿病患者血清TRAF3水平与FINS、2 h PG、HOMA-β、FPG呈显著正相关(P<0.05);多元线性回归分析结果显示,TRAF3、FINS、FPG、2 h PG、LDL-C、HbA1c均为2型糖尿病患者IR的影响因素(P<0.05,P<0.01);ROC曲线分析结果显示,血清TRAF3表达水平评估2型糖尿病患者IR的曲线下面积为0.818,敏感度和特异度分别为78.08%和73.00%。结论血清TRAF3表达水平与2型糖尿病患者胰岛功能和IR密切相关。展开更多
为探明不同灌溉制度对无膜滴灌棉花冠层光合有效辐射截获率(photosynthetically active radiation interception rate,PARI)的影响以及冠层PARI对棉花生长和产量形成的调控机制,于2021年开展田间试验,设置了4种灌溉制度,分别为花铃期灌...为探明不同灌溉制度对无膜滴灌棉花冠层光合有效辐射截获率(photosynthetically active radiation interception rate,PARI)的影响以及冠层PARI对棉花生长和产量形成的调控机制,于2021年开展田间试验,设置了4种灌溉制度,分别为花铃期灌水5次(W5)、6次(W6)、7次(W7)和8次(W8),对应的灌水频率分别为9、8、7和6 d。初花期前各处理的灌溉制度与常规大田相同,初花期后各处理灌水定额均为69 mm,W8最后一次的灌水定额为52.2 mm。各处理灌溉定额分别为366、504、573和625.2 mm。结果表明:盛花期W7在冠层垂直方向60~80 cm区域PARI最高,且吐絮期仍比W5高6.53%。W8灌溉制度存在贪青晚熟,吐絮期冠层PARI未明显下降。W7营养器官生物量积累显著低于W8,但生殖器官生物量积累比W8显著提高5%。随着灌水频率的增加,各处理冠层PARI逐渐增加,但产量先增加后下降,W7棉花产量最高。通过两种模型拟合发现,冠层PARI与棉花叶面积指数(leaf area index,LAI)和株高呈显著正相关关系(P<0.01),冠层光合有效辐射(photosynthetically active radiation,PAR)累积截获量与生殖器官生物量和总生物量积累符合logistic模型;多元线性回归方程可以用来预测棉花生长、冠层PAR累积截获量与生物量积累的关系。因此采用W7处理灌溉制度可以构建良好的棉花群体冠层并获得最佳增产效果,研究可为干旱区无膜栽培棉花高效灌溉制度的制定提供参考。展开更多
在新疆南疆地区自然生态条件下,以中棉所88号为试验材料,采用单因素随机区组试验设计,设置6个种植密度(P1:9万株·hm^(-2),P2:12万株·hm^(-2),P3:15万株·hm^(-2),P4:18万株·hm^(-2)、P5:21万株·hm^(-2),P6:24万...在新疆南疆地区自然生态条件下,以中棉所88号为试验材料,采用单因素随机区组试验设计,设置6个种植密度(P1:9万株·hm^(-2),P2:12万株·hm^(-2),P3:15万株·hm^(-2),P4:18万株·hm^(-2)、P5:21万株·hm^(-2),P6:24万株·hm^(-2)),研究了一膜六行机采棉模式下棉花株高、主茎日增长量、茎粗、节枝比、叶面积指数(leaf area index,LAI)、冠层开度、叶倾角和产量对种植密度的响应。结果表明:增大密度显著降低了棉花的株高、茎粗、单株叶面积、冠层开度及节枝比(P<0.05);主茎日增量在初花期以前为密度越大其越高,初花期后则反之;各处理LAI均在盛铃前期达到峰值,以P4处理最高为4.74;叶倾角则随密度增大而增大,各处理在30.0°~46.9°浮动;籽棉及皮棉产量均在P5处理达到最高,分别为6272.79 kg·hm^(-2)和2874.82 kg·hm^(-2)但其与P3、P4处理均无显著差异。综上得出,在一膜六行机采模式下,南疆棉花的种植密度在15万~18万株·hm^(-2)范围内,棉花株型及冠层结构良好,产量较高。展开更多
基金supported by the National Key Technology Support Program of China(No.2014BAD03B02)the Professional(Agricultural) Researching Project for Public Interests,China(Nos.201203096 and 201503121)the Earmarked Fund for the Modern Agro-Industry Technology Research System,China(No.CARS-18-17)
文摘The Yellow River valley is one of the three largest cotton production areas in China.An experiment was performed in cotton fields of Anyang,China from 2013 to 2014 to investigate the effects of nitrogen(N) application rate and the ratio between basal and topdressing N fertilizer on N balance in a soil-plant system,N use efficiency,and cotton yield.Five N application rates as treatments were applied with the same split application ratio.Half of the N(50% basal fertilizer) was applied at pre-planting and the other half(50% topdressing fertilizer) at the initial flowering stage.These treatments were:zero N(N0,control),90 kg N ha^(-1)(N90(5/5)),180 kg N ha^(-1)(N180(5/5)),270 kg N ha^(-1)(N270(5/5),a reduced N rate),and 360 kg N ha^(-1)(N360(5/5),a conventional N rate).Additional 2 split application ratios as treatments were applied with the same N rate of 270 kg N ha^(-1).The split application ratios between basal N and topdressing N were 30%:70%(N270(3/7)) and 70%:30%(N270(7/3)).Results demonstrated that soil NH_4-N content in the 0–60 cm layer and NO3-N content in the 0–20 cm layer increased with increased N rate at the squaring and boll-opening stages and then decreased to lower levels at the initial flowering and harvest stages.Soil NO_3-N content in the 20–60 cm layer after the initial flowering stage increased with the increase of topdressing N rate.Soil apparent N surplus varied at different growth stages,while the soil apparent N surplus over the entire growth period exhibited a positive relationship at N rates over 180 kg ha^(-1).Seed cotton yield of N270(3/7) was the highest of all treatments.Plant N uptake,N agronomic efficiency,and apparent N recovery efficiency of N270(3/7) were significantly higher than those of N270(5/5) and N270(7/3) in both growing seasons.These suggest both economic and ecological benefits in cotton production in the Yellow River valley could be created,by appropriately reducing total N application rate and increasing the ratio of topdressing to basal N fertilizer at the initial flowering stage.
基金Under the auspices of the National Natural Science Foundation of China (No. 40371030), Research Project of Ministry of Construction (No. 20031018)
文摘Researchers in several disciplines and fields agree that the image establishing has both perceptual and affecfive evaluations. The paper comparatively analyzes the image of landscapes in ancient water towns held by 1619 tourists after the investigations of Zbouzhuang and Tongli of Jiangsu Province. Based on the elements of the image of urban landscapes, the perceptual/cognitive image of tourist landscapes in water towns is developed including path, node, landmark, important courtyard, district and edge. Particularly the important courtyard plays the great role on the perceptive image of tourists, however, the perceptual/cognitive images of the district and the edge are obviously weak. Meanwhile, the finding showed that the affective images of tourist landscapes in Zhonzhuang differ with those of Tongli by the method of paired comparison. The main reason is that the affective images are influenced by the impressive scenery spots. Furthermore, the commercialization of streets and pollution of rivers are easy to be functioned negatively.
基金financially supported by the National Key Research and Development Program of China(Grant No.2019YFC1804301)the National Science Fourdation of China(Grant No.42272279,41902244)partial support from a Discovery Grant awarded by the Natural Sciences and Engineering Research Council of Canada(NSERC)。
文摘In groundwater hydrology,aquitard heterogeneity is often less considered compared to aquifers,despite its significant impact on groundwater hydraulics and groundwater resources evaluation.A semi-analytical solution is derived for pumping-induced well hydraulics and groundwater budget with consideration of vertical heterogeneity in aquitard hydraulic conductivity(K)and specific storage(S_(s)).The proposed new solution is innovative in its partitioning of the aquitard into multiple homogeneous sub-layers to enable consideration of various forms of vertically heterogeneous K or S_(s).Two scenarios of analytical investigations are explored:one is the presence of aquitard interlayers with distinct K or S_(s) values,a common field-scale occurrence;another is an exponentially depth-decaying aquitard S_(s),a regional-scale phenomenon supported by statistical analysis.Analytical investigations reveal that a low-K interlayer can significantly increase aquifer drawdown and enhance aquifer/aquitard depletion;a high-S_(s) interlayer can noticeably reduce aquifer drawdown and increase aquitard depletion.Locations of low-K or high-S_(s) interlayers also significantly impact well hydraulics and groundwater budget.In the context of an exponentially depth-decaying aquitard S_(s),a larger decay exponent can enhance aquifer drawdown.When using current models with a vertically homogeneous aquitard,half the sum of the geometric and harmonic means of exponentially depth-decaying aquitard S_(s) should be used to calculate aquitard depletion and unconfined aquifer leakage.
文摘目的分析2型糖尿病患者血清肿瘤坏死因子受体相关因子3(TRAF3)的表达水平与胰岛功能和胰岛素抵抗(IR)的相关性。方法选取2022年8月至2023年12月收治的148例2型糖尿病患者,根据胰岛素抵抗指数(HOMA-IR)值分为无IR组75例和IR组73例;另选80例同期体检健康者作为对照组。酶联免疫吸附法测定血清TRAF3的表达水平;Pearson和Spearman法分析血清TRAF3表达水平与空腹胰岛素(FINS)、餐后2 h血糖(2 h PG)、胰岛β细胞功能指数(HOMA-β)、胰岛素敏感指数(ISI)相关性;多元线性回归分析2型糖尿病患者发生IR的影响因素;受试者工作特征(ROC)曲线分析血清TRAF3表达水平对2型糖尿病患者IR的预测价值。结果2型糖尿病患者血清TRAF3水平高于体检健康者,无IR组患者血清TRAF3水平低于IR组(P<0.01)。2型糖尿病患者无IR组和IR组FINS、三酰甘油、低密度脂蛋白胆固醇(LDL-C)、糖化血红蛋白(HbA1c)、空腹血糖(FPG)、2 h PG、HOMA-IR、HOMA-β、ISI比较差异有统计学意义(P<0.05,P<0.01);2型糖尿病患者血清TRAF3水平与FINS、2 h PG、HOMA-β、FPG呈显著正相关(P<0.05);多元线性回归分析结果显示,TRAF3、FINS、FPG、2 h PG、LDL-C、HbA1c均为2型糖尿病患者IR的影响因素(P<0.05,P<0.01);ROC曲线分析结果显示,血清TRAF3表达水平评估2型糖尿病患者IR的曲线下面积为0.818,敏感度和特异度分别为78.08%和73.00%。结论血清TRAF3表达水平与2型糖尿病患者胰岛功能和IR密切相关。
文摘为探明不同灌溉制度对无膜滴灌棉花冠层光合有效辐射截获率(photosynthetically active radiation interception rate,PARI)的影响以及冠层PARI对棉花生长和产量形成的调控机制,于2021年开展田间试验,设置了4种灌溉制度,分别为花铃期灌水5次(W5)、6次(W6)、7次(W7)和8次(W8),对应的灌水频率分别为9、8、7和6 d。初花期前各处理的灌溉制度与常规大田相同,初花期后各处理灌水定额均为69 mm,W8最后一次的灌水定额为52.2 mm。各处理灌溉定额分别为366、504、573和625.2 mm。结果表明:盛花期W7在冠层垂直方向60~80 cm区域PARI最高,且吐絮期仍比W5高6.53%。W8灌溉制度存在贪青晚熟,吐絮期冠层PARI未明显下降。W7营养器官生物量积累显著低于W8,但生殖器官生物量积累比W8显著提高5%。随着灌水频率的增加,各处理冠层PARI逐渐增加,但产量先增加后下降,W7棉花产量最高。通过两种模型拟合发现,冠层PARI与棉花叶面积指数(leaf area index,LAI)和株高呈显著正相关关系(P<0.01),冠层光合有效辐射(photosynthetically active radiation,PAR)累积截获量与生殖器官生物量和总生物量积累符合logistic模型;多元线性回归方程可以用来预测棉花生长、冠层PAR累积截获量与生物量积累的关系。因此采用W7处理灌溉制度可以构建良好的棉花群体冠层并获得最佳增产效果,研究可为干旱区无膜栽培棉花高效灌溉制度的制定提供参考。
文摘在新疆南疆地区自然生态条件下,以中棉所88号为试验材料,采用单因素随机区组试验设计,设置6个种植密度(P1:9万株·hm^(-2),P2:12万株·hm^(-2),P3:15万株·hm^(-2),P4:18万株·hm^(-2)、P5:21万株·hm^(-2),P6:24万株·hm^(-2)),研究了一膜六行机采棉模式下棉花株高、主茎日增长量、茎粗、节枝比、叶面积指数(leaf area index,LAI)、冠层开度、叶倾角和产量对种植密度的响应。结果表明:增大密度显著降低了棉花的株高、茎粗、单株叶面积、冠层开度及节枝比(P<0.05);主茎日增量在初花期以前为密度越大其越高,初花期后则反之;各处理LAI均在盛铃前期达到峰值,以P4处理最高为4.74;叶倾角则随密度增大而增大,各处理在30.0°~46.9°浮动;籽棉及皮棉产量均在P5处理达到最高,分别为6272.79 kg·hm^(-2)和2874.82 kg·hm^(-2)但其与P3、P4处理均无显著差异。综上得出,在一膜六行机采模式下,南疆棉花的种植密度在15万~18万株·hm^(-2)范围内,棉花株型及冠层结构良好,产量较高。
