为了探究胶合板在室内开放环境下VOCs(挥发性有机化合物)释放的规律,选取18 mm厚的三聚氰胺浸渍纸饰面胶合板(MI)、PVC饰面胶合板(PVC)、水性漆饰面胶合板(WP)以及胶合板素板(UP)作为实验材料进行换气率为1次/h的循环试验,利用15 L VOC...为了探究胶合板在室内开放环境下VOCs(挥发性有机化合物)释放的规律,选取18 mm厚的三聚氰胺浸渍纸饰面胶合板(MI)、PVC饰面胶合板(PVC)、水性漆饰面胶合板(WP)以及胶合板素板(UP)作为实验材料进行换气率为1次/h的循环试验,利用15 L VOCs动态采样舱和气相色谱-质谱联用仪,对4种胶合板在实验的第1、3、7、14、21、28 d进行采样分析,进而得到VOCs的释放浓度与组分特征。结果表明:4种胶合板的VOCs浓度在释放平衡期受到装载率的影响要小于释放初期;MI释放初期在4种装载率条件下VOCs浓度差最大;装载率对于WP释放的VOCs浓度影响最小。饰面材料可以有效地阻隔板材内部芳香烃等VOCs向外散发。4种胶合板释放的VOCs浓度随装载率的增大呈现非线性上升趋势。占比大、浓度高的芳香烃类化合物随着装载率的变化呈现不同的增长趋势,醛类物质浓度较低,但总体上也随着装载率的增大而增大。实验测得4种胶合板释放的VOCs浓度以及醛类化合物的浓度均不超过优等品释放限值规定,本次研究为进一步探索胶合板优等品的最大装载率限量提供理论基础,也为室内装修胶合板的科学选材用材提供参考。展开更多
Background:Summer vegetative dormancy is a desirable trait in cool-season grasses when they are interplanted with annual crops.Sandberg bluegrass(Poa secunda J.Presl.)shows summer dormancy,but the environmental cues t...Background:Summer vegetative dormancy is a desirable trait in cool-season grasses when they are interplanted with annual crops.Sandberg bluegrass(Poa secunda J.Presl.)shows summer dormancy,but the environmental cues that control dormancy remain unknown.Methods:A controlled environment study using temperature and day length combinations of 32.2℃/15 h,26.6℃/14 h,21.1℃/13 h,and 15.5℃/12 h was conducted with P.secunda accessions PI232347,PI639272,and PI232348,and‘Audubon’red fescue as a nondormant control to determine the optimum treatment for dormancy induction.A second study using treatments of 26.6℃/14 h,21.1℃/13 h,and 15.5℃/12 h was conducted to determine the thresholds for dormancy release.A third study used a factorial experiment with two temperatures(32.2℃ and 15.5℃)and two day lengths(15 and 12 h)to differentiate between temperature and day length effects on dormancy induction.Results:Of the four temperature and day length combinations,all except for 15.5℃/12 h resulted in dormancy by the end of 6 weeks,with 32.2℃/15 h inducing dormancy in only 17 days.Of the three treatments for dormancy release,15.5℃/12 h broke dormancy the fastest in all accessions and released the most number of plants from dormancy.Considerable variation existed between accessions for the speed of dormancy release in the 21.1℃/13 h and 26.6℃/14 h treatments.The third study showed that temperature is the primary inducer for summer dormancy,while longer day length may promote dormancy under inductive temperatures.Conclusions:This study identified the optimum photothermal for induction and release of summer dormancy in P.secunda,which will help future studies in elucidating the mechanism of summer dormancy.展开更多
文摘为了探究胶合板在室内开放环境下VOCs(挥发性有机化合物)释放的规律,选取18 mm厚的三聚氰胺浸渍纸饰面胶合板(MI)、PVC饰面胶合板(PVC)、水性漆饰面胶合板(WP)以及胶合板素板(UP)作为实验材料进行换气率为1次/h的循环试验,利用15 L VOCs动态采样舱和气相色谱-质谱联用仪,对4种胶合板在实验的第1、3、7、14、21、28 d进行采样分析,进而得到VOCs的释放浓度与组分特征。结果表明:4种胶合板的VOCs浓度在释放平衡期受到装载率的影响要小于释放初期;MI释放初期在4种装载率条件下VOCs浓度差最大;装载率对于WP释放的VOCs浓度影响最小。饰面材料可以有效地阻隔板材内部芳香烃等VOCs向外散发。4种胶合板释放的VOCs浓度随装载率的增大呈现非线性上升趋势。占比大、浓度高的芳香烃类化合物随着装载率的变化呈现不同的增长趋势,醛类物质浓度较低,但总体上也随着装载率的增大而增大。实验测得4种胶合板释放的VOCs浓度以及醛类化合物的浓度均不超过优等品释放限值规定,本次研究为进一步探索胶合板优等品的最大装载率限量提供理论基础,也为室内装修胶合板的科学选材用材提供参考。
基金supported by a grant from USDA-NIFA(Award Number 2017-67019-26370 to K.J.M.,A.W.L.,&S.F.)a grant from the Iowa Nutrient Research Center(Grant no.2019-04 to S.F.,A.W.L.,K.J.M.,&A.A.C.).
文摘Background:Summer vegetative dormancy is a desirable trait in cool-season grasses when they are interplanted with annual crops.Sandberg bluegrass(Poa secunda J.Presl.)shows summer dormancy,but the environmental cues that control dormancy remain unknown.Methods:A controlled environment study using temperature and day length combinations of 32.2℃/15 h,26.6℃/14 h,21.1℃/13 h,and 15.5℃/12 h was conducted with P.secunda accessions PI232347,PI639272,and PI232348,and‘Audubon’red fescue as a nondormant control to determine the optimum treatment for dormancy induction.A second study using treatments of 26.6℃/14 h,21.1℃/13 h,and 15.5℃/12 h was conducted to determine the thresholds for dormancy release.A third study used a factorial experiment with two temperatures(32.2℃ and 15.5℃)and two day lengths(15 and 12 h)to differentiate between temperature and day length effects on dormancy induction.Results:Of the four temperature and day length combinations,all except for 15.5℃/12 h resulted in dormancy by the end of 6 weeks,with 32.2℃/15 h inducing dormancy in only 17 days.Of the three treatments for dormancy release,15.5℃/12 h broke dormancy the fastest in all accessions and released the most number of plants from dormancy.Considerable variation existed between accessions for the speed of dormancy release in the 21.1℃/13 h and 26.6℃/14 h treatments.The third study showed that temperature is the primary inducer for summer dormancy,while longer day length may promote dormancy under inductive temperatures.Conclusions:This study identified the optimum photothermal for induction and release of summer dormancy in P.secunda,which will help future studies in elucidating the mechanism of summer dormancy.
