冬小麦田O3气孔与非气孔沉降及风险评估

为了深入了解农田生态系统的O_3干沉降过程,并基于O_3通量(尤其是气孔O_3累积通量)指标进行风险评估,利用涡度相关系统对冬小麦田的O_3干沉降过程进行了连续动态观测,初步分析O_3浓度和总O_3通量的变化过程,着重探析气孔O_3沉降和非气孔O_3沉降的变化特征及其与主要气象因子的关系,并基于剂量指标(AOT40)和通量指标(DF_s06)分别推算出冬小麦的产量损失率.结果表明,观测期间(自2016年3月16日至5月30日)日平均O_3浓度(cO_3)为32.9 n L·L-1;白天(08:00~18:00)和夜间平均总O_3通量(F_(O3))分别为-7.6 nmol·(m~2·s)~(-1)和-3.1 nmol·(m~2·s)~(-1),日均F_(O3)为-5.1nmol·(m~2·s)~(-1).逐日平均气孔O_3通量(F_s)的变化范围为0~-5.1 nmol·(m~2·s)~(-1),日均F_s为-1.43 nmol·(m~2·s)~(-1).逐日平均非气孔O_3通量(F_(ns))的变化范围为-1.43~-10.31 nmol·(m~2·s)~(-1),日均F_(ns)为-3.66 nmol·(m~2·s)~(-1).较强的太阳辐射(SR)、较高的温度(T)和适度湿润的条件有利于冬小麦气孔沉降;较强的SR、适度的T和湿润条件是有利于冬小麦非气孔沉降.在整个观测期间,总O_3累积吸收通量(DF_(O3))、气孔O_3累积吸收通量(DF_s)和非气孔O_3累积吸收通量(DF_(ns))分别为31.58、9.99和21.59 mmol·m~(-2),总DF_s和总DF_(ns)分别占总DF_(O3)的32%和68%.通过剂量指标AOT40和通量指标DF_s06响应方程计算出的冬小麦产量损失率分别为11.58%~20.37%和20%~23.56%.     

土壤汞污染及修复措施研究进展

土壤汞污染已经严重危害到人类健康和生态环境,成为一个世界性问题,对其治理的各种修复措施也成为当前研究的一个热点。本文对土壤汞污染的来源、危害和修复措施等方面进行综述,指出了当前存在的问题,并对今后治理的研究方向提出了相关建议。     

Systematic analysis of microfauna indicator values for treatment performance in a full-scale municipal wastewater treatment plant

The indicator values of microfauna functional groups and species for treatment performancewere systematically evaluated based on the continuous monitoring of the entire microfauna communities including both protozoa and metazoa over a period of 14 months, in two parallel full-scale municipalwastewater treatment systems in a plant in Beijing, China. A total of 57 species of ciliates, 14 species (units) of amoebae, 14 species (units) of flagellates and4 classes of small metazoawere identified,with Arcella hemisphaerica, Vorticella striata, Vorticella convallaria, Epistylis plicatilis and small flagellates (e.g. Bodo spp.) as thedominant protozoa, and rotifers as thedominant metazoa. The abundance of the sessile ciliateswas correlatedwith the removals of BOD 5 (Pearson’s r = 0.410, p < 0.05) and COD Cr (r = 0.397, p < 0.05)while the testate amoebaewas significantly positively related to nitrification (r = 0.523, p < 0.01). At the same time, some other associationswere also identified: the abundances of the large flagellates (r = 0.447, p < 0.01), the metazoa (r = 0.718, p < 0.01) and species Aspidisca sulcata (r = 0.337, p < 0.05)were positively related to nitrification; the abundance of Aspidisca costatawas correlated to the TN (total nitrogen) removal (r = -0.374, p < 0.05 ); the abundances of the sessile species Carchesium polypinum (r = 0.458, p < 0.01) and E. plicatilis (r = 0.377, p < 0.05)were correlatedwith the removal of suspended solids.     

“五想五不干”行为安全观察系统开发与应用

为了有效管理和控制不安全行为,消除隐患,本文剖析了“五想五不干”的内涵,分析了“五想五不干”行为安全观察法的应用难点、使用原则与方法,并在网络环境下基于C#开发了“五想五不干”行为安全观察系统,通过系统运行的实践应用,验证了该方法的有效性与可操作性,可为行为安全的有效管理与控制提供借鉴.     

基于Surfer的衡阳气象地质灾害预警系统设计与实现

本文介绍了衡阳气象地质灾害预警系统的工作原理,系统架构设计、系统关键技术及预报效果验证情况。在Delphi环境下以Server2003为基础数据库,以Serfur为图形绘制工具完成了系统开发。系统以遍及衡阳的近300个自动气象站的降水实况资料及日本每天2次(08、20时)滚动数值预报产品为原始数据,通过模型计算未来24小时衡阳各乡镇出现地质灾害的危险等级,并自动形成预警服务产品。从2012年6月11日的地质灾害监测效果来看,系统能较好地监测气象地质灾害的发生,但由于数值预报精度不够,监测点预警危险系数粗放,放大了系统空报率。     

半导体企业环境风险防范措施建议

当前国际形势下,中国半导体行业不断创新发展。由于半导体行业的工艺技术特点,生产过程中必然涉及各类易燃易爆、有毒有害化学品。根据半导体生产行业特征及其环境风险水平,提出环境风险预防、控制、减缓措施,明确环境风险防范及应急要求,运用科学的技术手段和管理方法,尽可能降低环境风险事故发生。     

南昌市浅层地下水水质评价及监测指标优化

地下水环境监测过程中保证地下水水质评价代表性的同时尽量优化监测指标数量,对地下水环境管理具有重要的意义.选取南昌市地区2014年和2019年浅层地下水监测数据,运用统计分析、 Piper三线图和熵权水质指数(EWQI)分析水化学特征及水质变化,并耦合逐步多元线性回归分析构建基于水质评价的关键指标优化方法,评估此方法应用的可行性.结果表明,南昌市地下水2014年和2019年水化学类型主要为HCO₃-Ca型;pH值、 NO^-₃、 I^-、 Fe和Mn等5项超标指标是水质变化的主要影响因子;2019年水质状况总体上高于2014年,基本为“中等”水质,二者EWQI平均值分别为53.72和82.34;基于关键指标优化方法构建的最优模型EWQI_min-4能够较好地代表实际的EWQI,关键指标包括Mn、 NO^-₃、 TH、 Fe、 pH值和I^-,其决定系数(R²)和百分比误差(PE)值分别为0.865和10...     

Shortened fetal long bones: A notable intrauterine phenotypic feature in SHOX-associated skeletal dysplasia

Objective

To explore the intrauterine phenotypic spectrum of short stature homeobox-containing (SHOX) gene-associated skeletal dysplasia and provide genetic counseling at-risk pregnancies.

Method

We analyzed the fetuses with SHOX-microdeletions identified by single nucleotide polymorphism (SNP)-array. The intrauterine phenotypes and outcomes were further elaborated.

Results

Nine fetuses carrying a single SHOX-microdeletion were reported, with deletion sizes ranging from 0.134 to 1.35 Mb. Shortened long bones were observed in all fetuses, varying from −2.0 standard deviation (SD) to −5.3 SD. Moreover, all cases had a femur length/foot ratio less than 0.87 and a femur/abdominal circumference ratio greater than 0.16, suggesting that non-lethal skeletal dysplasia may be involved. Two fetuses showed intrauterine growth restriction, and two had nasal bone hypoplasia. Prenatal ultrasonography did not reveal other obvious anomalies, including the Madelung deformity. Five microdeletions were inherited and one was de novo. Five terminations and four newborns were recorded. Two newborns had normal stature, and two were short-statured (height <3rd percentile), with one having inflexible wrists.

Conclusions

SHOX haploinsufficiency may manifest with shortened fetal long bones. The combination of history taking, prenatal ultrasonography, and SNP-array can prompt early prenatal diagnosis and timely postnatal treatment of SHOX-associated skeletal dysplasia.     

应用构型一致的显式方法预测结构冲击动响应

目的 发展构型一致的显式方法,以提高拉格朗日有限元对冲击、碰撞及侵彻问题计算的精度和健壮性。方法 为更准确地描述和计算结构大变形,基于任意参考构型理论,建立构型一致的动量方程拉格朗日有限元格式。为避免网格间侵入现象,通过结合前增量位移的时间积分方法和共轭梯度算法,使得显式增量步更新后,仍满足接触非侵入条件。结果 通过对大变形碰撞及侵彻问题的模拟,并与LS-DYNA软件结果对比,验证了计算方法的可靠性。结论 基于构型一致的显式算法可有效抑制大变形碰撞过程的单元畸变,提高计算程序的健壮性和预测准确度,使该算法在模拟大变形碰撞问题方面具有优势。