Results 11 to 20 of about 4,560 (111)

不同年龄木麻黄林地根际土壤养分含量和酶活性动态

open access: yesShuitu Baochi Xuebao, 2006
在福建省东山县滨海沙地,开展了不同年龄木麻黄林地根际和非根际土壤养分和酶活性的测定,研究结果表明:(1)不同年龄木麻黄林地根际pH小于非根际土壤,随林龄增长根际土壤和非根际土壤pH值均表现为下降趋势;根际土壤有机质、全氮和水解氮含量高于非根际土壤,各土层有机质含量在中龄林时最大;从中龄林阶段至过熟林,水解氮含量下降;全磷和速效磷含量从幼林发育至中龄林、近熟林逐渐减少,至过熟林略有恢复;根际土壤全钾、速效钾含量呈增加趋势。(2)不同年龄木麻黄林地根际CEC值、水解性总酸度、交换性盐基总量、交换性Mg^2 ...
叶功富   +5 more
doaj   +2 more sources

黔中不同龄组柳杉人工林枯落物水源涵养能力综合评价

open access: yesShuitu Baochi Xuebao, 2020
为了解不同林龄柳杉人工林枯落物的水源涵养能力,为森林水土保持措施的确定和实施提供依据,于2018年10月选取平坝区大坡林场5个龄组柳杉人工林作为研究对象,采用烘干法和实验室浸水法对枯落物的持水性能进行研究,并采用熵权法对柳杉人工林5个龄组枯落物水源涵养能力进行综合评价。结果表明:(1)随着柳杉人工林的生长发育,枯落物储量及持水特性呈现先增加后减小的趋势,表现出成熟林最大,幼龄林最小。其中成熟林枯落物厚度为7.40 cm,蓄积量为2.21 t/hm2,最大持水量为6.46 t/hm2,最大持水率为265 ...
杨家慧, 谭伟, 卯光宪, 冯艳
doaj  

Machine Learning Model for an App‐Based Tool to Assist With the Diagnosis of Canine Atopic Dermatitis

open access: yesVeterinary Dermatology, Volume 37, Issue 2, Page 236-246, April 2026.
Canine atopic dermatitis (cAD) is a chronic condition requiring life‐long management. Accurate diagnosis can be challenging, with no reliable diagnostic test. This study aimed to generate a simple diagnostic model for cAD. This model is a relevant prototype for an app‐based tool to support general practitioners in the diagnosis of cAD alongside ...
Xavier Langon   +2 more
wiley   +1 more source

Life Stage‐Specific Genetic Diversity and Landscape Characteristics Collectively Influence Genetic Recovery in Pometia pinnata Population 生活史阶段特异的遗传多样性与景观特征对番龙眼种群遗传恢复的协同影响

open access: yesIntegrative Conservation, Volume 5, Issue 1, Page 137-149, March 2026.
Pometia pinnata demonstrated life‐stage‐specific genetic responses to landscape features, with asymmetric gene flow patterns and population recovery following historical bottlenecks, revealing complex topographic and demographic influences on forest genetic structure.
Madhuparna Chatterjee   +5 more
wiley   +1 more source

Participation Disenchants: How Online Political Participation Decreases Online Political Efficacy in China

open access: yesRegulation &Governance, Volume 20, Issue 1, Page 35-63, January 2026.
ABSTRACT Existing literature largely agrees that authoritarian regimes establish channels for political participation to gather valuable information on citizens' anti‐regime sentiments and policy preferences and to supervise lower‐level bureaucrats and firms.
Anton Bogs
wiley   +1 more source

Effect of aspirin on maternal hemodynamics in Chinese women at high risk for preterm pre‐eclampsia: longitudinal study

open access: yesUltrasound in Obstetrics &Gynecology, Volume 66, Issue 5, Page 621-630, November 2025.
ABSTRACT Objectives To compare the maternal hemodynamics of Chinese women at low and at high risk for preterm pre‐eclampsia (PE) and assess the differences in hemodynamic parameters between high‐risk women with or without prophylactic aspirin. Methods This was a prospective longitudinal case–control study of 857 Chinese women with a singleton pregnancy
X. Wang   +11 more
wiley   +1 more source

Aspirin delays preterm birth in pregnancies at high risk for preterm pre‐eclampsia: evidence from randomized clinical trial in Asia

open access: yesUltrasound in Obstetrics &Gynecology, Volume 66, Issue 1, Page 24-32, July 2025.
ABSTRACT Objectives To investigate the impact of aspirin administration on the incidence of preterm birth, according to the type of delivery and gestational age at preterm birth, and to examine the hypothesis that aspirin delays preterm delivery. Methods This was a secondary analysis of a multicenter stepped‐wedge cluster randomized trial of a first ...
H. H. Y. Leung   +29 more
wiley   +1 more source

不同林龄序列杉木实生林和萌芽林碳储量分配特征

open access: yesShuitu Baochi Xuebao, 2017
杉木林是我国南方地区的主要造林树种,研究不同更新方式的杉木林固碳及水土保持功能对科学评价森林生态系统的生态服务功能具有重要意义。以赣西南杉木实生林和萌芽林为研究对象,通过野外样地调查和室内化学分析方法,揭示了不同龄组实生林和萌芽林的碳储量分配特征,为其可持续经营提供科学依据。结果表明:不同龄组杉木实生林乔木层碳储量均高于萌芽林乔木层碳储量。杉木实生幼龄林乔木层碳储量为9.63 t/hm2,中龄林为42.14 t/hm2,近熟林为69.15 t/hm2,成熟林为105.21 t/hm2;年均固碳量分别为1.
唐学君, 王伟峰
doaj  

黄土高原不同林龄刺槐林土壤水分亏缺程度

open access: yesShuitu Baochi Xuebao, 2022
通过定点监测刺槐林土壤水分含量,探究不同林龄刺槐林土壤水分分布与亏缺程度。采用空间代替时间的研究方法,选择10,15,25,40年人工刺槐林为研究对象,农地(0年)为对照,调查分析0—200 cm土层土壤水分分布情况。结果表明:各样地平均土壤含水量大小顺序为农地(18.80%)>10年刺槐林(16.43%)>15年刺槐林(15.47%)>40年刺槐林(13.87%)>25年刺槐林(13.38%);不同林龄刺槐林土壤水分均处于亏缺状态,随着林龄增加,土壤水分亏缺呈增大趋势,平均土壤水分亏缺程度为19.38%
费洪岩   +4 more
doaj  

Use of prenatal ultrasound findings to predict postnatal outcome in fetuses with lower urinary tract obstruction

open access: yesUltrasound in Obstetrics &Gynecology, Volume 64, Issue 6, Page 768-775, December 2024.
Abstract Objective Lower urinary tract obstruction (LUTO) is a chronic condition with a spectrum of outcomes. It is usually suspected prenatally based on ultrasound features (USFs). Given the unknown postnatal trajectory and the potential for significant morbidity and mortality, many families choose termination of pregnancy (TOP), often based on USFs ...
J. Richter   +10 more
wiley   +1 more source

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