Bond population analysis on combination of favorable growth unit of Al(OH)_3 crystals

The quantum chemical calculation on four representative combination modes of the favorable growth unit Al6(OH)18(H2O)6 of Al(OH)3 crystals and the single unit were calculated. On the base of the prior investigation, and from the point of view of bond population and net atomic charge, the relationships between the combination mode of the favorable growth unit and the relative intensity of chemical bond of the systems were discussed. The quantum chemistry calculations were performed at RB3LYP/6-31G and RHF/6-31G levels by ab initio and DFT methods respectively. From the point of view of bond population, it can be preliminarily presumed that the interatomic bond force of the system with side-face-combination-B mode is weaker to a certain extent. From the point of view of the net charge, when the combination mode is obverse-face-combination-D, the interatomic bond force will be enhanced.

Growth units model of anion coordination-polyhedra and its application to crystal growth

Growth units model of anion coordination-polyhedra ACP model emphasizes the influence of intrinsic structure of crstal upon the crystal growth and the importance of the external conditions on which crystals grow. The ACP model is used to analyze some problems in crystal growth, such as the formation of dendrite in the crystal structure, growth habit of polar crystal, and formation of allomerism and polymorphism.

Growth Units and Formation Mechanisms of the Crystals Under Hydrothermal Conditions

The growth units and formation mechanisms of quartz(SiO_2)and barium titanate (BaTiO_3)crystals under hydrothermal conditions have been investigated by means of cataphoretic experi- ments.It is proposed that the growth units of the crystals in hydrothermal solutions have the structures of coordinative polyhedra of anions,which correspond to those of coordinative polyhedra in the crystals. The relationship between crystal morphology and physico-chemical conditions has been explained accord- ing to the modes of incorporation of the coordinative polyhedra of anions on the various faces of crystals. The dimensions of the growth units vary with the change of the growth condition.The incorporation rates on the various faces of the growth units with varied dimensions must be different,which leads to a satis- factory explanation for the variety of the crystal morphology.

The growth units and hydrothermal preparation of lead tungstate (PbWO_4) crystallites

The crystal structure of lead tungstate (PbWO4) can be regarded as ordered combination of the tungsten oxide tetrahedrons (WO4) and lead ions (Pb2+). According to the growth unit model, the growth units of lead tungstate are the aggregations of the tungsten oxide tetrahedrons and lead cations with various geometry configurations. It is suggested that the favorable growth units of lead tungstate crystal are pyramidal, tetragonal prism and quadrangular units corresponding to geometric orientations of the simple forms of the crystal. Under low restricted growth conditions, the growth form of lead tungstate crystallites is the aggregation of the geometric configurations of these favorable growth units. The above conclusions are completely confirmed by the experiment on hydrothermal preparation of lead tungstate crystallites.

Growth units and forming mechanism of KDP crystals

From the view of crystal chemistry, the growth units and forming mechanism of KDP crystals were investigated. The thickness of boundary layers changing with lattice faces was studied by \%in\|situ\% observation with Raman spectra, where the solution structure during crystal growth could be well observed. It was found that the solution structure at the boundary layer is similar to that of the crystal, so that the growth units are proposed as \[H\-2PO\-4\]\+-. The difference of growth rates of lattice faces is determined by the combination of growth units, which is mainly dominated by the angular orientation of K\|O and H\|O bonds. Consequently the reason about the difference of growth rates of lattice faces and the influence of pH value on the crystal morphology can be well elucidated.

Declining Vegetation Growth Rates in the Eastern United States from 2000 to 2010

Negative trends in the monthly MODerate resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) time-series were found to be widespread in natural (non-cropland) ecosystems of the eastern United Statesfrom 2000 to 2010. Four sub-regions were detected with significant declines in summed growing season (May-September) EVI, namely theUpper Great Lakes, the Southern Appalachian, the Mid-Atlantic, and the southeastern Coastal Plain forests ecosystems. More than 20% of the undeveloped ecosystem areas in the four sub-regions with significant negative EVI growing season trends were classified as forested land cover over the entire study period. We detected relationships between annual temperature and precipitation patterns and negative forest EVI trends across these regions. Change patterns in both the climate moisture index (CMI) and growing degree days (GDD) were associated with declining forest EVI growing season trends. We conclude that temperature warming-induced change and variability of precipitation at local and regional scales may have altered the growth trends of large forested areas of the easternUnited Statesover the past decade.

Mg_2(OH)_2CO_3·3H_2O Whiskers Growth Mechanism

From the perspective of growth units, the growth mechanism of Mg2（OH）2CO3.3H2O whisker is investigated in this paper. Results show that the growth morphology of Mg2（OH）2CO33H2O whisker is consistent with the model of anion coordination polyhedron growth units. The growth solution Raman shift of Mg2（OH）2CO;3H2O was monitored using Raman spectroscopy. The growth units are [Mg-（OH）4]2- and H2COv The growth process of Mg2（OH）2COf3H2O whisker is as follows： growth unit [Mg-（OH）4]2- first incorporates into the larger dimension [Mg-（OH）4]2-, then the [Mg-（OH）4]2-n combines with H2CO3 into a linear skeleton Mg2（OH）2CO3 in the same line. Mg2（OH）2CO3 combines with H2O by hydrogen bonds and ultimately transforms into Mg2（OH）2COf3H2O whisker. Magnesium carbonate whiskers have a layered structure, each of which is made of magnesium, carbon, oxygen, with H2O in between each layer. When skeletons are superimposed within the same plane as a parallelepiped one, they grow into solid cuboid-shaped whiskers. When the parallelepiped skeletons planes combine with each other through the cascading links, they grow into hollow cylindrical whiskers.

Growth Habit of the Basic Oxysulfate Magnesium Whisker

The growth habit of the basic magnesium oxysulfate whisker was investigated based on the theoreticalmodelof anion coordination polyhedron growth units.It is found that typicalbasic magnesium oxysulfate whisker growth is consistent with anion tetrahedralcoordination incorporation rules.The growth units of basic magnesium oxysulfate whiskers are [Mg-（OH）_4]^（2-） and HSO_4^-.[Mg-（OH）_4]^（2-） is the favorable growth unit and whisker growth is in the direction of the [Mg-（OH）_4]^（2-） combination.A plurality of [Mg-（OH）_4]^（2-） s combine and become a larger dimensionalgrowth unit in a one-dimensionaldirection.Then HSO_4^- and larger dimensionalgrowth units connect as basic magnesium sulfate whiskers,according to the structuralcharacteristics of the basic magnesium sulfate whisker,which can guide the synthesis of magnesium hydroxide whisker.

Unit GDP Energy Consumption in 2006:Moving from Increase to Decline

On July 12, Xie Fuzhan, Commissioner of National Bureau of Statistics of China attended the press conference held by State Council Information Office, and delivered the report on China＇s national unit GDP energy consumption in 2006, presenting with major indicators of unit GDP energy consumption both at national and regional levels in the year 2006.

撤县设区、空间一致性与县域经济发展

县域经济是我国实现城镇化发展的主战场。本文利用夜间灯光数据代理县域经济发展水平,突破统计数据受制于行政区划的空间限制,获得空间一致且跨时间可比的县域经济衡量指标。这不仅可避免因使用统计数据可能导致的可塑性面积单元问题,还可以同时分析“撤县设区”对县(市)和市辖区的影响,为“撤县设区”的研究提供更细致完整的图景。研究发现:“撤县设区”改革无论对被撤并县(市),还是对原市辖区的经济发展均未产生显著影响。原因在于,尽管“撤县设区”能够促进县域企业吸收更多人力资本,但却显著降低了企业的固定资产净投资和全要素生产率,这在一定程度上解释了为何“撤县设区”改革不能显著推动县域经济发展的原因。

秸秆为载体的印度梨形孢菌肥对水稻种子萌发和幼苗生长的影响

针对秸秆还田抑制种子发芽和幼苗生长的问题,将印度梨形孢菌液接种在水稻秸秆上制成生物菌肥,探讨菌肥活性及其对水稻种子发芽和幼苗生长的影响,以期为秸秆还田和生物菌肥的推广应用提供科学依据。以秸秆和泥炭为载体,制成两种生物菌肥,测定载体对菌株是否有毒性、菌肥在贮存期间有效存活菌落数的变化情况,确定秸秆是否适合做印度梨形孢的载体;以‘绿旱1号’为试验材料,设置生物菌肥做底肥和菌肥浸提液浸种两种施肥方式,分别设置秸秆处理(ST)、菌肥处理(BF)和常规施肥处理(CK)3种施肥处理,以及25%、50%、75%、100%共4个菌肥浸提液梯度和无菌水(CK)5种浸种处理,对比分析不同处理水稻种子的发芽指标、水稻幼苗的农艺性状指标、根系形态指标和生理指标的变化,评价施肥效果,筛选出合适的施肥浓度和施肥方式。结果表明:(1)印度梨形孢接种在秸秆和泥炭两种载体上0~6d内,有效存活菌落数显著增加,增幅分别为2.89倍和1.89倍(P<0.05)。秸秆为载体的印度梨形孢菌肥在室温条件下(25℃)贮存180d,随着时间推移,菌肥有效存活菌落数呈先升高后降低的趋势;与接种时相比,贮存30d和60d时有效存活菌落数显著增加32.08%和31.13%,贮存120d、150d和180d时显著降低61.23%、96.60%和98.70%(P<0.05)。(2)与秸秆处理相比,菌肥处理显著提高了水稻幼苗的单株重、茎长、根长、投影面积、表面积、根系活力、叶绿素a含量和叶绿素b含量。(3)菌肥浸提液抑制水稻种子萌发,浓度越高抑制作用越强;不同浓度菌肥浸提液对胚芽长、胚根长、幼苗根系形态指标、茎长、最长叶长、单株重表现出低促高抑的影响,其中,25%菌肥浸提液对上述指标均有明显的促生效果,浸提液原液(100%)使胚芽长、根系形态指标和单株重显著降低,降幅分别为34.07%、43.53%~63.97%和19.51%(P<0.05)。研究表明,秸秆还田背景下,以秸秆为载体接种印度梨形孢菌液制成生物菌肥适合水稻种植,复合肥与印度梨形孢菌肥按照3:1的比例混合做底肥施用和25%的菌肥浸提液浸种,是适合水稻种子萌发和幼苗生长的施肥方式和施肥浓度。

ICU护士职业死亡回避对创伤后成长的影响研究

目的了解ICU护士职业死亡回避与创伤后成长的现状,探讨ICU护士职业死亡回避及创伤后成长的相关性。方法于2023年4-8月,采用一般资料调查表、ICU护士职业死亡回避量表、创伤后成长量表对陕西省4所三级甲等医院的ICU护士开展问卷调查。结果职业死亡回避总分(55.42±6.24)分;创伤后成长总分(58.02±8.82)分。职业死亡回避与创伤后成长呈负相关(r=-0.480,P<0.01)。多元线性回归分析结果显示:职业死亡回避、年龄、职称、工作年限是影响ICU护士创伤后成长的主要因素(均P<0.05)。结论ICU护士职业死亡回避处于较高水平;创伤后成长处于中等水平。护理管理者可以从职业死亡回避层面出发,通过降低ICU护士的职业死亡回避来提高其创伤后成长水平,促进护士成长。

声音对NICU早产儿生长发育影响的系统评价再评价

目的检索并再评价声音对NICU早产儿生长发育影响的系统评价,为临床医务人员临床决策及早产儿健康干预策略的持续改进提供参考。方法计算机检索The Cochrane Library、Embase、PubMed、Web of Science、万方、中国知网、维普和中国生物医学文献数据库,检索关于声音对NICU早产儿影响的系统评价/Meta分析/荟萃分析,检索时间为建库至2023年5月。2名研究人员应用AMSTAR对文献进行方法学质量评价后,通过GRADE进行证据整理与分级。结果初检文献405篇,最终纳入文献20篇,AMSTAR质量评价结果表明,高等质量文献有5篇,其余15篇均为中等质量,纳入文献的总体方法学质量较低。采用GRADE系统对20篇系统评价的79条结局指标的证据质量评价结果显示,12条证据为中等质量,34条证据为低等质量,33条证据为极低质量。结论声音干预有利于改善NICU早产儿的相关生理指标、睡眠效率、行为状态、神经行为及大脑发育,可促进早产儿健康恢复,但系统评价的方法学质量和证据的质量均较低,临床实践需谨慎采纳有关证据,并逐步进行更加规范、严谨的研究。

一种改进型增长-跳跃的镍氢电池满充判定算法

镍氢电池的充电进程是其生命周期的重要一环,充电的饱和程度对电池的使用寿命具有显著的影响,且在充电过程中表现出来的端电压、温度等参数反映了电池的充电状态,然而市面上的平价电池充电器大部分采用稳压限流直冲方式,电压和电流波动较大,且不人为断电就会一直充电,这可能会缩短镍氢电池的使用寿命,同时专用的模拟集成IC充电芯片设计的电路复杂,维护性较差。本文设计了一种恒流下能在小型单片机上运行的改进型增长-跳跃满充判定算法,可以在电池充满或者是轻微过充后判定满充,从而实现健康充电,延长电池的使用寿命。

血清GDF-15、IL-33联合检测在ICU老年肺部感染患者诊断及预后中的应用价值

目的探究血清生长分化因子15(GDF-15)、白细胞介素-33(IL-33)联合检测在重症监护室(ICU)老年肺部感染患者诊断及预后中的应用价值。方法选取2021年2月至2023年2月入住该院ICU的73例肺部感染老年患者作为研究组,依据治疗30 d后患者的预后情况,将研究组分为生存组(52例)和死亡组(21例)。另选取同期入住该院ICU但未发生肺部感染的老年患者70例作为对照组。收集所有研究对象的临床资料进行比较分析,酶联免疫吸附试验(ELISA)检测所有研究对象血清中GDF-15、IL-33水平,通过多因素Logistic回归分析影响ICU老年肺部感染患者预后的因素,采用受试者工作特征(ROC)曲线分析血清GDF-15、IL-33水平对ICU老年肺部感染患者的诊断及预后评估的价值。结果与对照组比较,研究组血清GDF-15、IL-33水平均显著升高(P<0.05)。血清GDF-15、IL-33水平为ICU老年患者发生肺部感染的独立危险因素(P<0.05)。血清GDF-15、IL-33水平诊断ICU老年患者发生肺部感染的曲线下面积(AUC)分别为0.912、0.896、0.951,二者联合检测的AUC大于GDF-15、IL-33单独诊断(Z_(二者联合-GDF-15)=2.630、Z_(二者联合-IL-33)=2.432,P=0.009、0.015)。生存组与死亡组年龄、体质量指数、性别、血小板计数、血清肌酐、血红蛋白、尿素氮比较,差异均无统计学意义(P>0.05);而死亡组白细胞计数、中性粒细胞计数及血清GDF-15、IL-33水平均高于生存组(P<0.05),淋巴细胞计数低于生存组(P<0.05)。多因素Logistic回归分析结果显示,中性粒细胞计数、白细胞计数、血清GDF-15、IL-33水平为ICU老年肺部感染患者发生死亡的独立危险因素(P<0.05),淋巴细胞计数为ICU老年肺部感染患者发生死亡的独立保护因素(P<0.05)。血清GDF-15、IL-33单独及二者联合预测ICU老年肺部感染患者预后情况的AUC分别为0.870、0.836、0.960,二者联合检测的AUC大于GDF-15、IL-33单独诊断(Z_(二者联合-GDF-15)=2.521、Z二者联合-IL-33=2.946,P=0.012、0.003)。结论血清GDF-15、IL-33水平在ICU老年肺部感染患者中升高,对其诊断及预后均具有一定的价值,且二者联合诊断及预测预后的效能更优。

负离子配位多面体生长基元在晶体生长中的应用

It has been pointed out by the theoretic model of anion coordination polyhedra of growth units that the crystal form is dominated by the stability of combination of anion coordination polyhedra on the growth interface.The face has the fastest growth rate and disappears easily if the vertex of coordination polyhedron is pointed at.The face has the slowest growth rate and appears easily if the plane of coordination polyhedron is pointed at.The growth rate is in median for the face that the edge of coordination polyhedron is pointed at.A few of problems are discussed in the paper on the basis of this theory. (1)Several examples of the morphology of allomorph and homoeomorphism are given in the paper.There are three allomorphs of TiO 2 rutile,brookite and anatase.The morphology of these allomorphs are totally different because the stability of combination of octahedral [Ti O 6] 8- vary with the orientation and linked edges of coordination polyhedra.Another example is the homoeomorphism of cassiterite SnO 2.The orientation and combination of octahedral [Sn O 6] 8- in cassiterite are similar to that of octahedral [Ti O 6] 8- in rutile,so that cassiterite and rutile have similar morphology even for their form of twin and twin face.The combination of octahedral [Al O 6] 9- ,[Fe O 6] 9- and [Ti O 6] 8- respectively is similar at the orientation and linked form of coordination polyhedra in three crystals of corundum,hematite and ilmenite,so the same faces appear in these three crystals,resulted in similar morphology.

基于异速生长法则的油茶树主干自然频率经验公式推导及应用

为克服油茶果人工采摘率低,该研究根据油茶树体合轴分枝生长方式,结合树体异速生长法则,建立油茶分形树体理想模型,提取二分叉基本单元。基于经典质量-弹簧分析方法,建立3种不同质点分布的二分叉基本单元动力学模型,推导一阶自然频率计算表达式。以湖南省华鑫油茶品种为应用实例,通过测量油茶树形态学参数,辨识面积缩减系数和异速生长系数,采用水浸法和三点弯曲试验分别测量油茶树枝密度和弯曲弹性模量。计算不同分枝角度下二分叉基本单元的一阶自然频率理论值。创建二分叉基本单元ANSYS有限元仿真模型,通过模态分析得到自然频率仿真值,质量均分在刚性杆两端的动力学模型的自然频率ANSYS仿真值与理论计算值较接近,平均相对误差为7.3%。基于带端部质点的悬臂梁一阶自然频率计算公式,采用参数辨识方法推导二分叉基本单元一阶自然频率经验公式,自然频率的经验公式计算值与仿真值最大误差仅为0.41%,验证了经验计算公式的准确性。研究结果可为油茶果振动式采摘装置的激振参数设置供理论依据。

ICU患者谵妄发展轨迹及危险因素研究

目的探讨ICU患者谵妄不同变化轨迹及危险因素,为谵妄管理提供理论依据。方法于2023年3月至2023年12月采用方便抽样法选取兰州大学第一医院重症医学科的ICU患者为研究对象,使用一般资料调查表、ICU意识模糊评估法(CAM-ICU)和ICU意识模糊评估表-7(CAM-ICU-7)、Richmond躁动-镇静评分(RASS)在收入ICU后的第24 h后(T1)进行基线评估和谵妄评估,对发生谵妄的患者在入院后第2、3、4、5 d(T2~T5)时间点使用RASS、CAM-ICU和CAM-ICU-7连续监测谵妄。采用潜类别增长模型识别谵妄轨迹类别,并分析不同类别的影响因素。结果共纳入269例ICU患者,其中126例发生谵妄。102例谵妄患者完成全程5次调查,ICU患者谵妄发生率为42.86%。潜类别增长模型结果显示含3个潜类别亚组的模型拟合结果最好,并分别命名为“持续谵妄组”(30.4%)、“高风险下降组”(29.4%)和“低风险上升组”(40.2%)。单因素分析结果显示,性别、镇静药使用类型以及不同时间点RASS评分对不同谵妄发展轨迹有影响(P<0.05)。多分类Logistic回归分析结果显示,相较于持续谵妄组,ICU患者谵妄发展为高风险下降组的预测因素主要包括性别和镇静药使用类型;相较于持续谵妄组,ICU患者发展为低风险上升组的预测因素为T1、T5时间点的RASS评分。结论ICU患者谵妄发展轨迹存在群体异质性,可分为3个潜类别,性别、镇静药使用类型和RASS评分是ICU患者谵妄发展轨迹潜类别的影响因素,医护人员应根据不同的谵妄变化轨迹对ICU患者进行个性化管理。

不同林龄华北落叶松优势木生长与空间结构的关联性

【目的】优势木的生长与其周围的相邻木密切相关,探究不同林龄林分中相邻木构成的空间结构特征对目标林木生长的影响,可以为调整空间结构进而激发林分生长潜力提供理论依据。【方法】选择27 a、37 a和46 a 3种不同林龄的华北落叶松人工林,分别设置面积为90 m×60 m、120 m×120 m和120 m×120 m的大样地,以优势木和其最近4株邻近木构建空间结构单元,计算每株优势木的角尺度、大小比数、混交度和密集度等指标,分析不同林龄中优势木在不同空间结构间的生长差异。【结果】优势木胸径和树高年均增长量均有显著的林龄差异,年均增长量随林龄增大而降低。在27 a林分的结构单元中,处于随机分布、优势、零度混交和密集状态的优势木占比最高,优势木平均胸径分别在角尺度为0.50、大小比数为0、混交度为0.75和密集度为1时最大,优势木平均树高分别在角尺度为0、大小比数为0、混交度为0.75和密集度为0.75时最大。在37 a的结构单元中,处于随机分布、优势、零度混交和非常密集状态的优势木占比最高,优势木平均胸径分别在角尺度为0.50、大小比数为0、混交度为0.5和密集度为0时最大,优势木平均树高分别在角尺度为0、大小比数为0、混交度为0.25和密集度为1时最大。在46 a的结构单元中,处于随机分布、优势、零度混交和稀疏状态的优势木占比最高,优势木平均胸径分别在角尺度为0.50、大小比数为0和密集度为0时最大,优势木平均树高分别在角尺度为0、大小比数为0和密集度为0时最大。【结论】水平分布格局、树种多样性、自身个体大小和树冠竞争影响优势木生长特征。在演替过程中,优势木朝着减小聚集程度和竞争压力的方向上发展,适当提升优势木的混交程度和保证优势木个体的生长优势利于其胸径和树高生长。在质量选择阶段,宜进一步选择生长好的优势木作为目标树,适当抚育采伐,优化结构单元,以人工促进天然更新等手段提升林分稳定性。在近自然阶段,应及时清理枯立木,通过人工促进天然更新和清除干扰木,继续优化空间结构。

基于δ^(13)C估算水分利用效率的2种模型比较——以峨眉山雷洞坪植物为例

【目的】通过对基于碳稳定同位素值(δ^(13)C)估算水分利用效率(iWUE)的2种模型(是否考虑叶肉导度,gm)之间差异的研究,有助于进一步理解gm对植物iWUE的影响。【方法】选择峨眉山雷洞坪针阔混交林中不同生长型植物,采集了48个物种的117个叶片样品,通过测定其叶片δ^(13)C,对比了早期估算iWUE模型(iWUEsim模型,将gm看作无穷大)与包含gm效应的iWUE模型(iWUEmes模型)之间的iWUE差异(iWUE_(difference)),以及这种差异随植物生长型变化的趋势。【结果】结果显示,iWUEsim的平均值(42.23±1.33μmol·mol^(-1))显著高于iWUEmes的平均值(28.10±0.65μmol·mol^(-1)),高估比例为3.64%~72.11%(平均49.58%±1.30%)。不同生长型植物的iWUEsim均显著大于iWUEmes,其中草本植物高估比例3.64%~48.00%(平均29.20%±5.16%),灌木高估比例13.68%~67.73%(平均48.44%±1.83%),乔木高估比例32.04%~72.11%(平均54.08%±1.47%)。此外,叶片功能性状对iWUE_(difference)有显著影响,相比于叶片厚度、叶片干物质含量和单位质量叶片氮含量,单位面积叶片氮含量和比叶重是影响iWUE_(difference)变化的主要因素。【结论】将gm看作无穷大会造成对基于δ^(13)C估算的iWUE的高估,未来估算植物iWUE时应考虑gm的影响。