Designing ultrastable P2/O3-type layered oxides for sodium ion batteries by regulating Na distribution and oxygen redox chemistry

P2/O3-type Ni/Mn-based layered oxides are promising cathode materials for sodium-ion batteries(SIBs)owing to their high energy density.However,exploring effective ways to enhance the synergy between the P2 and 03 phases remains a necessity.Herein,we design a P2/O3-type Na_(0.76)Ni_(0.31)Zn_(0.07)Mn_(0.50)Ti_(0.12)0_(2)(NNZMT)with high chemical/electrochemical stability by enhancing the coupling between the two phases.For the first time,a unique Na*extraction is observed from a Na-rich O3 phase by a Na-poor P2 phase and systematically investigated.This process is facilitated by Zn^(2+)/Ti^(4+)dual doping and calcination condition regulation,allowing a higher Na*content in the P2 phase with larger Na^(+)transport channels and enhancing Na transport kinetics.Because of reduced Na^(+)in the O3 phase,which increases the difficulty of H^(+)/Na^(+) exchange,the hydrostability of the O3 phase in NNZMT is considerably improved.Furthermore,Zn^(2+)/Ti^(4+)presence in NNZMT synergistically regulates oxygen redox chemistry,which effectively suppresses O_(2)/CO_(2) gas release and electrolyte decomposition,and completely inhibits phase transitions above 4.0 V.As a result,NNZMT achieves a high discharge capacity of 144.8 mA h g^(-1) with a median voltage of 3.42 V at 20 mA g^(-1) and exhibits excellent cycling performance with a capacity retention of 77.3% for 1000 cycles at 2000 mA g^(-1).This study provides an effective strategy and new insights into the design of high-performance layered-oxide cathode materials with enhanced structure/interface stability forSIBs.

P507溶剂浸渍树脂吸附Ga(Ⅲ)的性能研究

溶剂浸渍树脂(SIRs)分离法兼具溶剂萃取与离子交换两种分离方法的优点,且树脂制备简单,可根据实际情况灵活选用不同的载体和萃取剂,有望实现镓绿色、高效的分离回收。本文以苯乙烯-二乙烯基苯大孔吸附树脂(代号:HZ818)为载体、2-乙基己基膦酸单2-乙基己基酯(代号:P507)为萃取剂,制备P507 SIRs,研究了该SIRs在H 2SO 4体系中吸附Ga(Ⅲ)的性能。静态吸附实验表明:298 K时,P507 SIRs对Ga(Ⅲ)的最佳吸附pH值为3.3,对应吸附量为13.7 mg·g^(-1);吸附平衡时间为14 h,动力学吸附过程可用拟二级动力学方程描述;等温吸附均符合Langmuir等温吸附模型。动态吸附实验表明:低流速有利于P507 SIRs对Ga(Ⅲ)充分吸附;1.5 mol·L^(-1)的HCl可以将吸附于P507 SIRs上的Ga(Ⅲ)完全洗脱;P507 SIRs对Ga(Ⅲ)循环吸附稳定性能有待提高。在Ga(Ⅲ)-Zn(Ⅱ)、Ga(Ⅲ)-Cu(Ⅱ)二元混合体系中,P507 SIRs对Ga(Ⅲ)具有较好的吸附选择性,通过控制溶液pH值可以实现Ga(Ⅲ)的分离富集;在含Fe(Ⅲ)的Ga(Ⅲ)-Fe(Ⅲ)二元体系和Ga(Ⅲ)-Zn(Ⅱ)-Cu(Ⅱ)-Fe(Ⅲ)多元体系中,P507 SIRs对Fe(Ⅲ)表现出较好的吸附选择性,而对Ga(Ⅲ)吸附甚微,表明Fe(Ⅲ)的存在对P507 SIRs吸附Ga(Ⅲ)产生较大干扰。

慢性心力衰竭患者血清Ⅲ型前胶原氨基末端前肽、高迁移率族蛋白B1、NT-proBNP的表达及临床意义

目的:检测慢性心力衰竭(CHF)患者血清Ⅲ型前胶原氨基末端前肽(N-terminal peptide of typeⅢprocollagen,PⅢNP)、高迁移率族蛋白B1(high mobility group box-1,HMGB1)的表达水平,探讨二者与左室射血分数(LVEF)的相关性以及对CHF的诊断价值。方法:收集2021年12月至2022年11月期间于佳木斯大学附属第一医院心内科住院治疗的慢性心力衰竭患者90例为实验组,按照LVEF将其分为HFrEF组(n=33)、HFmrEF组(n=27)和HFpEF组(n=30)。此外选取排除心功能不全诊断的同期住院患者30例为对照组。对比各组患者血清中氨基末端脑钠肽前体(NT-proBNP)、PⅢNP、HMGB1水平的差异,分析PⅢNP、HMGB1水平与心功能指标的相关性,并借助ROC曲线评估NT-proBNP、HMGB1、PⅢNP单独以及联合应用对不同表型CHF患者的诊断价值。结果:HFrEF组PⅢNP、HMGB1及NT-proBNP水平均高于HFpEF组和对照组,差异有统计学意义(P<0.05)。PⅢNP与HMGB1呈正相关(P<0.05);PⅢNP、HMGB1均与NT-proBNP、LVEDD呈正相关,与LVEF呈明显负相关(P<0.05);HMGB1与LAD呈正相关(P<0.05),PⅢNP与LAD无明显相关性(P>0.05)。血清NT-proBNP、HMGB1、PⅢNP水平诊断HFrEF患者的AUC分别为0.867、0.871、0.779;诊断HFmrEF患者的AUC分别为0.840、0.804、0.760;诊断HFpEF患者的AUC分别为0.851、0.728、0.769。多生物标志物模型NT-proBNP+PⅢNP、NT-proBNP+HMGB1、NT-proBNP+PⅢNP+HMGB1诊断HFrEF患者的AUC分别为0.887、0.954、0.954;诊断HFmrEF患者的AUC分别为0.942、0.937、0.951;诊断HFpEF患者的AUC分别为0.904、0.910、0.914。结论:CHF患者血清PⅢNP、HMGB1明显升高,并且,CHF患者血清PⅢNP、HMGB1水平与心脏功能指标具有良好的相关性,说明PⅢNP、HMGB1可反映疾病的严重程度。PⅢNP、HMGB1对各表型CHF患者均具有诊断价值,并且,多生物标志物联合检测能提高对CHF患者诊断的敏感性。

纳武利尤单抗联合安罗替尼对Ⅲb~Ⅳ期NSCLC的疗效观察及对miR-1269、miR-204-5p表达的影响

目的探究纳武利尤单抗联合安罗替尼治疗Ⅲb~Ⅳ期非小细胞肺癌(NSCLC)患者的效果及对微小RNA-1269(miR-1269)、miR-204-5p表达的影响。方法选取Ⅲb~Ⅳ期NSCLC患者82例,患者分配为对照组、观察组,各41例,使用随机数字表法,对照组采用安罗替尼治疗,观察组在对照组的基础上采用纳武利尤单抗治疗;比较两组患者的疗效、治疗前后肿瘤标志物癌胚抗原(CEA)、细胞角蛋白19片段抗原21-1(CYFRA21-1)、miR-1269、miR-204-5p表达水平和不良反应的发生率。结果观察组患者治疗后疾病控制率(87.80%,36/41)显著高于对照组(68.29%,28/41)(χ^(2)=4.556,P=0.033);与治疗前相比,治疗后观察组和对照组的CEA、CYFRA21-1、miR-1269水平显著降低,miR-204-5p水平显著升高(P<0.05);治疗后与对照组相比,观察组的CEA、CYFRA21-1、miR-1269水平显著降低,miR-204-5p水平显著升高(P<0.05);不良反应两组间比较,差异无统计学意义(P>0.05)。结论纳武利尤单抗联合安罗替尼治疗Ⅲb~Ⅳ期NSCLC患者可降低患者肿瘤标志物的水平,调节miR-1269、miR-204-5p的表达,效果更好。

基于ERK/p38 MAPK信号通路探究解毒活血汤治疗Ⅲ型前列腺炎的作用机制

目的探究解毒活血汤调控ERK/p38 MAPK信号通路治疗Ⅲ型前列腺炎的作用机制。方法采用去势手术+苯甲酸雌二醇(EB)诱导慢性前列腺炎大鼠模型。36只SD大鼠随机分为空白组(生理盐水,4 mL·kg^(-1))、模型组(生理盐水,4 mL·kg^(-1))、阳性药物对照组(前列康片混悬液,4 mL·kg^(-1))、解毒活血汤低(4 mL·kg^(-1))、中(8mL·kg^(-1))、高剂量组(12 mL·kg^(-1)),每组6只,所有实验动物连续给药30 d。苏木精-伊红(HE)染色观察各组大鼠组织病理学变化;免疫组化法、RT-PCR、Western Blot技术检测相关炎症因子及蛋白表达水平。结果与正常对照组相比,慢性前列腺炎大鼠前列腺组织增生及水肿明显、炎症浸润增加,而阳性药物对照组及解毒活血汤各剂量组大鼠前列腺组织病变减轻或消失、炎症浸润减少,且与解毒活血汤剂量成正比;免疫组化表示模型组p38、P-p38、STAT3、P-STAT3表达较高,阳性药物对照组、不同剂量解毒活血汤组的p38、P-p38、STAT3、P-STAT3表达呈下降趋势,且均低于模型组。RT-PCR结果显示阳性药物对照组及解毒活血汤低、中、高剂量组均能降低大鼠前列腺组织中TNF-α、IL-2、IL-6的表达水平;Western Blot检测提示大鼠疾病发生进展过程中p38、P-p38、P-ERK1/2、STAT3、P-STAT3呈高表达状态,解毒活血汤能够降低其表达,从而降低相关炎症因子的过度激活。结论解毒活血汤能够抑制ERK/p38 MAPK信号通路的过度激活,从而降低IL-2、IL-6、TNF-α等炎症因子的表达,以改善前列腺组织炎症反应。

Efficient removal of Al(Ⅲ)and P507 from high concentration MgCl_(2)solution based on in-situ reaction strategy

For a highly efficient recycling of a wastewater containing a high concentration of MgCl_2,Al(Ⅲ)and P507 were scheduled to be removed in advance.In this study,the in-situ removal of Al(Ⅲ)and P507 from a high concentration MgCl_(2)solution at different pH values and Al/P molar ratios was investigated.The results showed that P507 formed organic complexes of Al_x(OH)_y~(Z+)-P507 at pH of 2.0-4.0.At pH of 4.0-5.0,Al(Ⅲ)precipitated and transferred into Al(OH)_(3)with a flocculent amorphous morphology.Active sites on the Al(OH)_(3)surface enhanced the removal efficiency of P507.At pH of 6.0-6.5,Al(Ⅲ)and Mg(Ⅱ)formed layered crystalline Al(OH)_(3)and MgAl_2(OH)_(8with)small pore channels and fewer active sites,resulting in a reduced removal efficiency of P507.When the Al/P molar ratio exceeded 13 and the pH was between 4.0 and 5.0,the removal rates of both Al(Ⅲ)and P507 were higher than98%,while the concentration loss of Mg(Ⅱ)was only 0.2%-0.9%.

Dislocation distribution model of mode Ⅲ propagation crack

Dislocation distribution functions of the edges of mode Ⅲ propagation crack subjected to three types of loads were studied by the methods of the theory of complex variable functions,by which,the problems researched were facilely transformed into Riemann-Hilbert problems and Keldysh-Sedov mixed boundary value problems. Analytical solutions of stresses,displacement and dynamic stress intensity factor were obtained by the measures of the theory of self-similar functions and corresponding differential and integral operation. In terms of the relationship between dislocation distribution functions and displacements,analytical solutions of dislocation distribution functions were obttained,and variational rules of dislocation distribution functions were depicted.

Spatial Distribution of Soil Total Nutrients of Farmland in Liaoning Province

[Objective]The aim was to reveal the spatial distribution characteristics of total nutrients in soil and provide a theoretical basis for farmland management and improvement of crop yield. [Method]GIS technique was used to analyze the spatial distribution characteristics of total C,total N,total P and total K for different soil layers in Liaoning Province. [Result]The results showed that the content of total C,total N,total P decrease from east to west,but the content of total K was high in north district of Liaoning Province. The content of total C,total N,total P and total K was higher in soil surface （0-20 cm） than the lower （20-40 cm）. Total K varied less with soil depth,and its mean content was respectively 17.64 g/kg and 17.08 g/kg for soil surface and soil lower layer. [Conclusion]The results of the distribution of soil total nutrients in different soil layers supplied a theory basis for farmland management.

miR-223-3p通过靶向TGFBR3促进LncRNA ADAMTS9-AS2表达上调抑制肺癌细胞的增殖和迁移作用

目的:探讨miR-223-3p通过靶向转化生长因子-βⅢ型受体(TGFBR3)促进长链非编码RNA(LncRNA)ADAMTS9-AS2表达上调抑制肺癌细胞增殖和迁移的作用及可能机制。方法:采用RT-PCR检测肺癌H1299细胞中miR-223-3p和TGFBR3 mRNA表达水平,Western blotting检测TGFBR3的蛋白表达水平,RT-qPCR检测LncRNA ADAMTS9-AS2的表达水平,CCK-8检测细胞增殖能力,Transwell细胞迁移实验和划痕实验检测细胞迁移能力。采用脂质体转染miR-223-3p模拟物(过表达组)、抑制剂(抑制组)、对照质粒(对照组)于H1299细胞中,比较各组转染前后miR-223-3p、TGFBR3、LncRNA ADAMTS9-AS2表达水平、细胞增殖能力、细胞迁移能力。结果:与转染前比较,过表达组转染后的H1299细胞中miR-223-3p、LncRNA ADAMTS9-AS2表达水平均升高(P<0.05),TGFBR3蛋白和mRNA表达水平均降低(P<0.01和P<0.05),细胞增殖和迁移能力下降(P<0.05);抑制组转染后的细胞中miR-223-3p和LncRNA ADAMTS9-AS2表达水平均降低(P<0.05),TGFBR3蛋白和mRNA表达水平均升高(P<0.01和P<0.05),细胞增殖和迁移能力均增加(P<0.05)。转染72 h后,TGFBR3蛋白表达水平及mRNA的表达水平细胞增殖与迁移能力:抑制组>观察组>过表达组(P<0.01)。3组miR-223-3p、LncRNA ADAMTS9-AS2 mRNA表达水平逐渐降低,抑制组<对照组<过表达组(P<0.01)。结论:miR-223-3p抑制肺癌H1299细胞的增殖和迁移,靶向下调TGFBR3和上调LncRNA ADAMTS9-AS2表达可能为其作用机制。

基于电磁时间反演P范数判据的配电网故障定位

目前电磁时间反演(electromagnetic time reversal,EMTR)多应用在单一线路故障定位,且现有判据在高阻抗接地情况下效果不理想。针对上述问题,基于EMTR故障定位原理和均匀传输线理论推导了传播过程中线路故障信号与测量信号的传递函数,根据传递函数的相关性提出了P范数判据。利用ATP-EMTP搭建10 kV配电网线路,对比了2范数与P范数判据在复杂配电网中的定位性能,并验证了所提判据在混合配电网线路的适用性。最后,分析了配电网发生低阻抗及高阻抗接地故障下P范数判据的鲁棒性。仿真结果表明,该方法在过渡电阻高达3 kΩ的情况下能准确定位,且定位精度高,受噪声、故障类型和采样频率的影响小。

高压管汇材料疲劳性能测试及P-S-N模型曲线的拟合

高压管汇作为压裂设备中的主要易损件之一,其失效危害较大。它的失效原因主要是疲劳、冲蚀、腐蚀或者材料缺陷引起的刺漏和爆裂,其中尤以疲劳失效最不可预估。目前,对于高压管汇材料的疲劳性能研究不够深入,为解决高压管汇材料疲劳寿命的准确描述问题,以某国产高压管汇材料为例,进行了一系列疲劳试验,并基于试验数据,采用多种分布模型和不同S-N模型进行拟合分析,得出综合评价拟合能力最强的P-S-N模型。结果表明,该材料在中长疲劳寿命区,Weibull三参数模型在7级应力水平下综合评价能力最好;在存活率分别为50%、90%、99%、99.9%时,指数S-N模型的拟合系数均大于0.98,拟合能力最好。得出的P-S-N模型曲线可以为高压管汇的疲劳寿命以及安全设计提供依据。

采用非稳相偏振滤波的DAS-VSP数据P/S波分离方法及其应用

分布式光纤声学传感(DAS)因成本低、易布设以及高密度采样等优势正成为重要的地震观测技术,尤其是越来越多地与垂直地震剖面(VSP)结合,用于主动地震勘探或被动地震监测.DAS传感器通过感知弹性波场产生的轴向应变或应变速率来观测地震波场振动.然而,目前单分量DAS-VSP数据未完整地记录地下弹性波场的三维矢量振动信号,因此如何从中分离出P波或S波用于后续地震成像与参数反演是重要且很有挑战的课题.以弹性波传播理论为基础,本文根据P波和S波的频散关系估算接收点处各自的偏振方向,通过随频率和空间位置变化的偏振滤波实现DAS-VSP数据的P/S波分离.理论模型合成数据与东海实际DAS-VSP数据实验结果表明,该方法能有效地将P波和S波信号从单分量DAS-VSP数据中分离出来,可为后续纵横波速度反演、PP与PS波成像提供关键的数据预条件处理.

抗凝血酶Ⅲ和膜糖蛋白CD62P对特发性膜性肾病发生栓塞风险的研究

据研究统计,慢性疾病给人们造成巨大的经济损失,长期遗留的并发症也严重影响着人们的生活质量。肾脏病也逐渐增加,现在已成为常见慢性疾病,肾病综合征是其中常见类型。原发性肾病综合征的发病病理类型有20%是特发性膜性肾病,近年仍有上升的趋势。特发性膜性肾病常见且严重的并发症是血栓栓塞,血栓栓塞一旦发生会危及患者的生命安全并且严重影响预后与未来生活质量,因此预防血栓栓塞的发生有重要作用。本文探讨抗凝血酶Ⅲ与血小板膜糖蛋白CD62P这两个指标对发生血栓栓塞的风险预测。

通过基体晶粒和颗粒分布异质结构的调控协同提升AlN_(p)/Al复合材料的强度-塑性

为了获得优异的强塑性能,采用液固反应结合后续的热机械处理方法制备了3种具有不同微观组织构型的异构AlNp/Al复合材料,详细研究了AlN颗粒分布和基体晶粒组织构型对拉伸强度和塑性的影响。结果表明,复合材料的强度和塑性同时提高。其中,具有较弥散颗粒分布的Uniformed-AlNp/Al复合材料表现出优异的极限抗拉强度(~387 MPa)和断裂伸长率(~9.1%)。与其他文献报道的颗粒增强铝基复合材料相比,该复合材料具有较好的比强度和延展性组合。此外,计算了异质变形诱导(HDI)应力。结果表明,在Uniformed-AlNp/Al复合材料中,HDI应力显著增加。揭示了HDI应力在提高AlNp/Al复合材料的强度和塑性中起着至关重要的作用。

The Limitations of Polygenic Hypothesis and Theorizing about Dual Multiple Factors and Three Normal Distributions

The original data of Nilsson-Ehle experiment in wheat were analyzed with existent genetic knowledge. It indicated that the core of polygenic hypothesis from this experiment was that a character similarity produced by additive effect of multiple genes was the basis of continuous variation. Its precondition was for effective genes to have equal effect, to show merodominance and binomial distribution and to inherit independently. In fact, quantitative characters were determined by many genes with different property, effect and behavior. So it was difficult to solve all problems of continuous variation by the aid of polygenic hypothesis. The researchers should seek new ways. With Mendelian group as research object and by means of Lyapunov central limit theorem it was proved that both genotypic value G and the environmental effect in a niche E were subordinated to the normal distribution and respectively. According to additivity of the normal distribution the phenotype P = G + E also obeyed the normal distribution P = G + E ~ and quantitative characters showed continuous variation, whether or not the linkage was presented, whether or not every gene effect was equal, whether or not there were dominance and what kind of dominance between alleles. Moreover it was discussed that the quantitative characters in self-fertilized organism and clone were submitted to the normal distribution and presented continuous variation too.

The Study on the Stability Constant and Species Distribution of Eu (III) and Tb (III) Complexes with BDBPH

The stability constants and species distributions of complexes of two lanthanide ions, Eu（Ⅲ） and Tb（Ⅲ）, with a macrocyclic ligand, BDBPH, in 1：1 and 2：lsystem, were determined potentiometrically at 25.0 ℃ and I=0.100 mol L^-l. The two metal ions could form deprotonated mono- or dinuclear complexes with BDBPH after the first two protons of the ligand completely neutralized. At higher pH values, Eu（Ⅲ） could not form hydroxy complexes with BDBPH, while Tb（Ⅲ） could form hydroxy complexes in the type of M2L（OH）, M2L（OH）2, and M2L（OH）3.

MICP固化钙质砂的统计损伤本构模型

目前关于微生物固化体的本构模型研究较少,本文基于Lemaitre应变等价性理论的损伤模型,假定微生物固化体的微元强度服从对数正态随机分布,假设微元破坏符合D-P准则,建立MICP固化钙质砂的统计损伤本构模型。根据试验数据确定本构模型中的参数S_(0)和参数F_0,并对其物理意义进行讨论,将该模型理论结果与试验结果进行对比,验证了该模型的合理性,最后分析了损伤变量D,参数S_(0)和参数F_0随碳酸钙含量变化的演化规律。研究结果表明:参数F_0反映微生物固化钙质砂的极限强度特性,参数S_(0)代表其脆性和延性特征;胶结水平越高,损伤速度越快,损伤值越大,随轴向变形持续增大,损伤变量最终会趋于稳定;该模型能够较好地模拟应变软化和应变硬化现象,同时可以反映体积应变曲线的剪胀和剪缩特性。本研究成果可为MICP固化土体的工程应用提供一定的理论基础。

沙库巴曲缬沙坦钠对缺血性心肌病患者MMP-2、PⅢNP水平及心功能的影响

目的探讨沙库巴曲缬沙坦钠片对缺血性心肌病患者基质金属蛋白酶2(MMP-2)、Ⅲ型前胶原氨基末端肽(PⅢNP)、肌钙蛋白T(cTnT)表达水平及心功能影响。方法选择2017年11月~2019年12月期间进行治疗的ICM患者87例,根据数字表法随机分为对照组43例,观察组44例;对照组给予β受体阻滞剂、阿司匹林、呋塞米、地高辛等常规药物治疗。观察组在对照组基础上给予沙库巴曲缬沙坦钠片治疗;对比两组患者治疗后临床效果、血清中MMP-2、PⅢNP、cTnT、心功能和用药期间不良反应等。结果观察组有效率86.36%,对照组为65.12%(P<0.05);两组血清中MMP-2、PⅢNP、cTnT治疗前比较差异无统计学意义(P>0.05),治疗后两组较治疗前比较血清中MMP-2、PⅢNP、cTnT均显著下降(P<0.05),且观察组更明显(P<0.05);两组治疗后较治疗前比较,LVEF得到提升,LVEDd、LVESd下降(P<0.05),且观察组更明显(P<0.05);两组用药期间未发现有不良反应。结论沙库巴曲缬沙坦钠在缺血性心肌病患者的治疗中能明显提高患者心功能,改善血清指标,提高安全性。

HA、LN及PⅢP检测在CHB患者肝纤维化的早期诊断中的价值分析

目的:探讨透明质酸(Hyaluronic Acid,HA)、人层黏连蛋白(Laminin,LN)及三型前胶原末端肽(Pciiinp,PⅢP)检测对慢性乙型肝炎(Chronic Hepatitis,CHB)患者肝纤维化的早期诊断价值。方法:回顾性分析2019年8月-2021年3月期间收治经穿刺活检证实CHB患者63例的临床资料。另选取同期健康体检者58例为对照组。分析CHB患者的进展阶段;比较各阶段CHB患者和对照组血清HA、LN及PⅢP水平、肝纤维化分期与HA、LN及PⅢP的水平关系、肝功能(Child-Pugh,CHILD)分级与血清HA、LN及PⅢP的水平关系;HA、LN及PⅢP联合检测对CHB患者肝纤维化的诊断价值。结果:以组织穿刺活检为金标准比较,HA、LN及PⅢP联合检测诊断准确率、灵敏度、特异度分别为83.82%(57/68)、94.82%(55/58)、40.00%(2/5)。肝硬化组血清HA、LN及PⅢP水平均显著高于慢性乙型肝炎重度组、中度组、轻度组和对照组(P<0.05)。肝纤维化分期S4期血清HA、LN及PⅢP水平均显著高于S2-S3、S0-S1期和对照组(P<0.05)。CHILD分级C级组血清HA、LN及PⅢP水平均显著高于S2-S3、S0-S1和对照组。结论:血清HA、LN及PⅢP参与CHB患者肝纤维化的发生与发展,能作为早期疾病诊断CHB肝纤维化和评估病情严重程度的重要指标。

Analysis of the characteristics of snow drop size distribution in the Qilian Mountains

Under the Watershed Allied Telemetry Experimental Research （WATER） project, a significant amount of snow size data was collected from March to April 2008. However, because of limited observation data for the Qinghai-Tibet Plateau, the modeling behavior was not satisfactory. This paper demonstrates characteristics of the snow drop size distribution （SSD） in this region. The experimental area is located in the northeastern part of the Qinghai-Tibet Plateau. The Heihe River Basin, which is the second largest interior river basin in China and is located on the northern slopes of the Qilian Mountains, was selected as the simulation region. This basin ranges from approximately 5,000 m to 1,000 m in elevation. A new generation Parsivel disdrometer, the OTT Parsivel, was used for measurements. Four data sets were compiled to determine the average distributions for four different snowfall rates. The characteristics of the snow particle size distribution in the mountainous area were analyzed. Similar to the raindrop distribution, there was a multi-peak structure. Most peaks appear in the D 〈 2 mm region （D： diameter of the snow drop size）. An M-P distribution and a Г distribution were developed based on the precipitation data observed in Qilian mountainous area. We found that the Г distribution has a better fit than the M-P distribution for the actual distribution. In addition, we observed that the intercept parameter （N0） and the slope parameter （Λ） correlate well with the shape parameter （μ）. The disdrometer data can also be used to model the reflectivity factor （ZH） and differential reflectivity factor （ZDR）. The radar reflectivity （ZHH, ZVV） and differential reflectivity （ZDR） were modeled in order to facilitate understanding of the connections between radar and ground measurements, and were used to support work for the improvement of rainfall estimates by polarimetric radar. Rain rate estimation using radar measurements was based on empirical models, such as the Z-R relationship and R（ZH, ZDR） in the Qilian mountainous areas. The relationship of R=0.017×100.079×ZH-0.022×ZDR is better than R=0.019×100.078×ZH for estimating R （melted snow）. The normalized errors （NE） of R（ZH） and R（ZH, ZDR） are 13.22% and 5.20%, respectively.