非层状二维CdSe的制备及厚度对带隙的影响

二维半导体材料的天然带隙有望弥补石墨烯的零带隙缺陷,打破后者在场效应晶体管、开关器件、逻辑电路等领域的应用瓶颈. 相较于层状半导体材料,非层状半导体材料多以较强的离子键/共价键结合,且各向同性,因此要获取其二维结构存在一定挑战. 本论文通过化学气相沉积法实现了非层状CdSe在云母衬底上的二维各向异性生长. 详细表征了二维CdSe的微观形貌、晶体结构和光学特性等. 结果表明,样品具有显著的光致发光 (PL )效应,说明厚度减薄至纳米级时不会破坏CdSe的直接带隙属性. 此外,随着厚度减小,样品的PL峰逐渐蓝移. 为了进一步解释该现象,采用基于密度泛函理论的第一性原理计算方法,研究了不同厚度的CdSe的能带结构,结果显示均为直接带隙,且随厚度减小,带隙值增大,与实验现象吻合. 由此可知,通过生长参数调控二维CdSe的厚度,即可实现对其带隙的有效调控,这对相关光电器件的性能提升具有指导意义.

基于网络药理学和分子对接探究白术调节氧化应激的作用机制

试验基于网络药理学和分子对接技术,研究白术调节氧化应激的活性成分及作用机理。通过TCMSP数据库筛选白术的成分及作用靶点,从GeneCards和OMIM数据库获得氧化应激靶点。借助STRING 11.5平台和Cytoscape 3.7.2软件构建白术-成分-靶点网络和PPI网络,筛选核心靶点。应用DAVID数据库进行GO和KEGG通路富集分析。使用AutoDockTools软件进行分子对接,考察活性成分与核心靶点的结合效能。结果显示,筛选得到6个主要活性成分,分别为12-千里光酰基-8-反式白术三醇、14-乙酰基-12-千里光酰基-8-反式白术三醇、α-香树脂醇、β-谷甾醇、3β-乙酰氧白术酮和8β-乙氧基白术内酯Ⅲ,关键作用靶点133个。GO功能富集筛选出460条目,KEGG通路注释得到127条信号通路,包括肿瘤坏死因子(TNF)、糖尿病并发症中的晚期糖基化终产物受体(AGE-RAGE)、白细胞介素-17(IL-17)及磷脂酰肌醇3-激酶(PI3K-Akt)等信号通路。分子对接结果显示,白术活性成分与核心靶点具有较好的结合活性,其中α-香树脂醇与白蛋白(ALB)、表皮生长因子受体(EGFR)、丝裂原活化蛋白激酶1(MAPK1)、醌氧化还原酶1(NQO1)及前列腺素合酶2(PTGS2)结合活性最好。研究表明,白术可能通过调控TNF、AGE-RAGE、IL-17及PI3K-Akt等信号通路及氧化应激相关靶点发挥抗氧化作用。

引黄滴灌灌水器流道水流模拟及堵塞成因研究

为探究大田引黄滴灌系统灌水器流道的堵塞机理,以减少大田灌水器系统堵塞,根据山西运城尊村灌区泥沙特点利用SolidWorks绘图软件进行灌水器流道的建模设计,以大田滴灌实际工程条件设置仿真参数,采用Ansys Fluent仿真软件进行不同型号灌水器流道的仿真计算模拟。研究此灌水器的压力、流速、湍动能等湍流特性以及颗粒的运动轨迹,揭示其内部流动机理。灌水器内部流体域压力随流道单元线性降低,并且压降梯度与流道单元数量线性相关;主流区流体更新快,泥沙不易发生沉积,流道旋涡区以及储水槽倒角部位是泥沙发生沉积的主要部位;流道高速区以外的其他区域以及储水槽部位整体湍流动能较低,水流无法形成或维持湍流状态,不利于泥沙运移,从而形成堵塞。模拟结果表明,灌水器内部结构流体域流速、湍流动能以及流线等分析均表明在灌水器流道部分的低速区和储水槽部位的倒角和边壁处是发生泥沙颗粒沉积的主要部位。

Synthesis, Crystal Structure and Theoretical Calculations of a New Co(Ⅱ) Coordination Polymer Based on 5-Nitroisophthalic Acid and Bis(imidazol) Ligands

A new complex[Co（NIPH）（mbix）]n（1,H2NIPH = 5-nitroisophthalic acid,mbix =l,3-bis（imidazol-l-ylmethyl）benzene） has been hydrothermally synthesized and structurally characterized by elemental analysis,IR spectrum,UV spectrum,TG and single-crystal X-ray diffraction.Pink crystals crystallize in the triclinic system,space group P1 with a = 8.3797（8）,b= 10.2522（10）,c= 13.4244（13） A,α=94.820（2）,β=108.105（2）,γ=104.816（2）°,V=1042.84（17） A^3,C（22）H（17）CoN5O6,Mr = 506.34,Dc = 1.613 g/cm^3,F（000） = 518,Z = 2,μ（MoKα） =0.876 mm^（-1）,the final R = 0.0505 and wR = 0.1254 for 3267 observed reflections（I〉2σ（I））.The structure of 1 exhibits a two-dimensional network structure and is extended into a three-dimensional supramolecule through hydrogen bonds and n-n interactions.In addition,Natural Bond Orbital（NBO） analysis was performed by using the PBE0/LANL2 DZ method built in Gaussian 09 Program.The calculation results showed obvious covalent interactions between the coordinated atoms and Co（Ⅱ） ion.

A New Two-dimensional Cd(Ⅱ) Complex Assembled by 1,3,5-Benzenetricarboxylic Acid and 3-(2-Pyridyl)pyrazole

A new 2D coordination polymer, {[Cd5(BTC)2(L)4(H2O)2]n·2H2O}n(1, H3BTC = 1,3,5-benzenetricarboxylic acid, HL = 3-(2-pyridyl)pyrazole) was synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction, powder XRD, IR, TGA, fluorescence spectrum and elemental analysis techniques. Complex 1 belongs to the monoclinic system, P21/c space group, with a = 8.8732(4), b = 17.5179(7), c = 17.8123(7) ?, β = 103.1830(10)°, V = 2695.77(19) ?3 and Z = 2. It features a 2D network constructed by BTC and L ligand. In addition, we analyzed Natural Bond Orbital(NBO) by using the PBE0/LANL2DZ method built in Gaussian 09 Program. The calculation results indicated obvious covalent interactions between the coordinated atoms and Cd(Ⅱ) ion.

Hydrothermal Synthesis and Crystal Structure of a Novel Isophthalate-bridged Copper(II) Polymer with Two-dimensional Network Structure: [Cu_2(phen)(ipt)_2]_(2n)·nH_2O (ipt = isophthalate, phen = 1,10-phenanthroline)

A novel metal-organic coordination polymer [Cu2（phen）（ipt）2]2n-nH2O 1 has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. The complex crystallizes in monoclinic, space group P21/c with a = 12.338（3）, b = 12.167（3）, c = 18.167（4）A, β= 111.686（14）°, V = 2534.1（10）A^3, C28H18Cu2N2O9, Mr = 653.52, Dc = 1.713 g/cm^3,μ（MoKα） = 1.740 mm^-1, F（000） = 1320, Z = 4, the final R = 0.0443 and wR = 0.0853 for 3543 observed reflections （1 〉 2σ（I））. It exhibits a novel two-dimensional network with tetra-Cu-ipt-as building units.

Two New Mn(Ⅱ)/Co(Ⅱ) Complexes Assembled by 2,5-Dihydroxy-1,4-benzenedicarboxylic Acid and Phenanthroline or Derivative

Two new complexes [Mn(DHTA)(PLQ)]n(1) and{[Co2(DHTA)(phen)2(H2 O)6]· DHTA}n(2)(H2 DHTA = 2,5-dihydroxy-1,4-benzenedicarboxylic acid, PLQ = 1,10-phenanthroline-5,6-quinone, phen = 1,10-phenanthroline) have been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, fluorescence spectrum, single-crystal and power X-ray diffraction. Complex 1 exhibits a two-dimensional(2 D) network, which was stabilized through O–H···O hydrogen bonding interactions. Complex 2 shows a zero-dimensional structure, which was further extended into a three-dimensional supramolecular structure through O–H···O hydrogen bonds and π-π interactions.

A New One-dimensional Complex Assembled by 4-Nitrobenzoic Acid and Bis(imidazol) Ligands:Syntheses, Structures and Theoretical Calculations

A new Zn(Ⅱ)coordination polymer,[Zn(nba)2(mbix)]2n(1,Hnba=4-nitrobenzoic acid,mbix=1,3-bis(imidazol-1-ylmethyl)-benzene),was synthesized and characterized by elemental analyses,IR spectra,TG,fluorescence spectroscopy,single-crystal and powder X-ray diffractions.It belongs to the triclinic system,P1 space group,with a=9.341(2),b=13.029(3),c=23.660(6)A,α=99.603(6)°,β=90.461(6)°,γ=90.597(5)°,V=2838.9(12)?3 and Z=2.It shows one-dimensional chains which are further linked by C–H···O hydrogen bonds andπ-πstacking interactions to yield a three-dimensional supramolecular structure.In addition,the Natural Bond Orbital(NBO)was analyzed in using the PBE0/LANL2DZ method built in Gaussian 09 Program.The calculation results indicated obvious covalent interaction between the coordinated atoms and Zn(Ⅱ)ion.

Synthesis,Crystal Structure and Theoretical Calculations of a Nickel(Ⅱ) Coordination Polymer Assembled by 4,4'-Oxydibenzoic Acid and 1,3-Bis(imidazol-1-ylmethyl)-benzene Ligands

A new metal-organic coordination polymer [Ni（oba）（mbix）（H2O）]n·n H2O（H2oba = 4,4‘-oxydibenzoic acid,mbix = 1,3-bis（imidazol-1-ylmethyl）-benzene） 1 has been hydrothermally synthesized and structurally characterized by elemental analysis,IR,TG,UV and single-crystal X-ray diffraction.Green crystals crystallize in the triclinic system,space group P1 with a = 10.1915（18）,b = 11.415（2）,c = 12.314（2）A,α = 74.263（3）,β = 84.545（2）,γ = 74.369（3）o,V = 1327.6（4） A,C28H26N4 Ni O7,Mr = 589.24,Dc = 1.474 g/cm3,F（000） = 612,Z = 2,μ（Mo Kα） = 0.786 mm-1,the final R = 0.0332 and w R = 0.0869 for 4622 observed reflections（I 〉 2σ（I））.The structure of 1 exhibits a one-dimensional chain-like structure.In addition,natural bond orbital（NBO） analysis was performed by the PBE0/LANL2 DZ method in Gaussian 03 Program.The calculation results show obvious covalent interaction between the coordinated atoms and Ni（Ⅱ） ion.

Effect of relative humidity at either acute or chronic moderate temperature on growth performance and droppings' corticosterone metabolites of broilers

The present study aimed to investigate the effect of relative humidity(RH) at either acute or chronic moderate ambient temperature(Ta) on growth performance and droppings' corticosterone metabolites of broilers.Two experiments were conducted: effect of RH(35,60 or 85%) on average daily feed intake(ADFI) and droppings' corticosterone metabolites at acute(1 d: 20–26 or 31–20°C,26 or 31°C for 6 h d–1 at 10:00–16:00) moderate Ta(experiment 1) and effect of RH(35,60 or 85%) on growth performance and droppings' corticosterone metabolites at chronic(step-wisely increasing temperature by 3°C every 3 d from 20 to 32°C within 15 d: 20–23–26–29–32°C) moderate Ta(experiment 2).Droppings were collected at the 2,4,6,8,and 22 h after Ta-RH controlled in experiment 1 and at the 2,4,6,and 22 h after Ta controlled to 32°C in experiment 2.The results showed that: 1) In experiment 1,85% RH increased(P<0.05) the droppings' corticosterone metabolites at the 2,6,8,and 22 h and 35% RH increased(P<0.05) it at the 2 and 22 h compared to the 60% RH.Moreover,85% RH further increased(P<0.05) it compared to the 35% RH,however,no difference(P>0.05) was found in ADFI among the three RH groups at acute moderate 26°C; 35 and 85% RH increased(P<0.05) droppings' corticosterone metabolites at the 2,6,8 and 22 h and decreased(P<0.05) ADFI compared to the 60% RH,moreover,85% RH further increased(P<0.05) droppings' corticosterone metabolites and further decreased(P<0.05) ADFI compared to the 35% RH at acute moderate 31°C; and the average of droppings' corticosterone metabolites in the whole period had a negative correlation(P<0.02) with the ADFI.2) In experiment 2,85% RH increased(P<0.01) droppings' corticosterone metabolites only at the 2 h and decreased(P<0.02) ADFI and average daily gain(ADG) compared to the 60% RH,no difference(P>0.05) in droppings' corticosterone metabolites was found between the 35 and 60% RH,however,35% RH decreased(P<0.01) ADG compared to the 60% RH,and the average of droppings' corticosterone metabolites in the whole period also had a negative correlation(P<0.02) with ADFI and ADG.In conclusion,droppings' corticosterone metabolites could be used as a RH stress index and low and high RH,especially high RH,reduced growth performance possibly through inducing RH stress at moderate temperature.

女性的自我意识苏醒与抗争——《群芳亭》与《阳与阴》中的女性书写

赛珍珠和荷巴特作为中西两种文化的边缘人以及在男权社会中处于劣势地位的女性,在《群芳亭》和《阳与阴》中不约而同地对中国女性进行了塑造。以比较文学形象学、女性主义和东方主义为理论基础,从身体的解脱和灵魂的觉醒两个方面对《群芳亭》和《阳与阴》中的吴太太和沈师母进行细致文本分析,并结合社会文化探讨两位作家对中国女性的不同塑造。赛珍珠强调只要有爱,中西两种文化就能得以共存,荷巴特则认为中西两种文化没有优劣之分,只有找到符合自己的文化,才能在两种文化碰撞中得以圆满。

无机盐、维生素及生长调节剂对花脸香蘑菌丝生长的影响

以花脸香蘑菌株“ts916”为供试菌株,采用平板培养法,在培养基中加入不同种类及质量浓度的无机盐、维生素和植物生长调节剂,研究供试物质对花脸香蘑菌丝生长的作用。结果表明,供试无机盐中,适量质量浓度的磷酸二氢钾、硫酸镁对花脸香蘑菌丝生长有促进作用,而氯化钠、氯化钾、氯化钙、硫酸锌、硫酸锰、硫酸铜抑制花脸香蘑菌丝生长。当硫酸镁质量浓度为1.5 g·L^(-1)时,花脸香蘑菌丝生长速度最快,为4.88 mm·d^(-1)。供试维生素(VB1、VB2、VB6、VC、叶酸和烟酸)在一定范围内均可显著促进花脸香蘑菌丝的生长,其中当VB6质量浓度为4 mg·L^(-1)时,花脸香蘑菌丝生长速度最快,为6.63 mm·d^(-1)。供试植物生长调节剂中,6-BA、2,4-D、NAA抑制花脸香蘑菌丝的生长,GA3的添加对花脸香蘑菌丝生长影响不显著。

“双减”背景下语文群文阅读教学的有效策略

“双减”背景下,教师应通过运用多种教学法,充分激发学生的学习兴趣,提高课堂教学效率,切实减轻学生的课业负担。初中语文教学可采用群文阅读教学法,让学生分小组围绕“议题”展开多文本阅读、比对读议、分工又合作,形成竞赛模式,提高课堂效率,培养学生的语文能力,提升其核心素养。

A型口蹄疫病毒抗体化学发光免疫分析检测方法的建立

为建立动物血清中的A型口蹄疫病毒抗体化学发光免疫分析检测方法,通过获得的A型口蹄疫病毒VP1融合蛋白与相关单克隆抗体建立了A型口蹄疫病毒抗体竞争化学发光检测试剂盒。该方法能够特异性的定量检测猪、牛、羊血清中的A型口蹄疫病毒VP1蛋白抗体,敏感性高,特异性强,对其他相关的偶蹄类动物病原无交叉反应,批内变异系数小于10%,批间变异系数小于15%,具有良好的重复性。对该方法的特异性指标和敏感性指标进行了验证,同国产的A型口蹄疫抗体检测试剂盒进行了比较,阳性样品符合率为92.63%,阴性样品符合率为93.98%,总符合率为93.17%。建立的A型口蹄疫病毒抗体化学发光免疫分析检测方法,特异性高,敏感性强,操作简单、快速,具有较高的应用推广价值。

不同种类木屑栽培黑木耳的比较试验

通过对黑木耳在10种不同木屑上菌丝生长、出耳情况、生物学效率、子实体营养成分等方面的比较研究表明,以苹果木、柞木、桑木、栗木屑为基质栽培的黑木耳菌丝长速快、长势好,出耳整齐、耳片较厚,生物学效率、子实体蛋白质和粗纤维含量均较高,这4种木屑均可以作为栽培黑木耳的原料;而以杨木木屑为基质栽培的黑木耳农艺性状表现最差,子实体营养成分含量较低,因此杨木木屑不宜作为黑木耳的栽培原料.

不同保藏时间对侧耳属3个种母种的影响

通过研究侧耳属平菇(Pleurotus ostreatus)、杏鲍菇(Pleurotus eryngii)、秀珍菇(Pleurotus geesteranus)3个主要栽培种母种的不同保藏时间对菌丝生长、酶活性和生物学效率的影响,表明侧耳属3个菌种的母种随着保藏时间的延长,菌落萌发时间延长,菌丝生长速度减慢,菌丝长势减弱,生物学效率降低,出菇污染率升高。随着保藏时间的延长,平菇木聚糖酶酶活性降低,羧甲基纤维素酶和淀粉酶酶活性几乎不变;杏鲍菇3种酶酶活性随保藏时间延长均逐渐降低;秀珍菇淀粉酶酶活性随保藏时间延长而降低,其他2种酶酶活性几乎不变。研究证明侧耳属3个栽培种母种保藏时间不宜超过3个月。

一个灵芝新品种的选育与分子鉴定

以国家认定品种“泰山赤灵芝1号(TL-1)”和野生灵芝菌株“4895”为亲本,通过原生质体单核化杂交育种技术选育出集亲本优势于一体的灵芝新品种“TL-3”,与TL-1相比,其在子实体形态特征、产量、生物学效率、子实体有效成分含量方面具有更大的优势。TL-3菌丝洁白浓密,子实体肾圆形,菌盖中等偏大,菌盖厚度显著高于TL-1(P<0.01),平均单产和生物学效率比TL-1分别提高12.23%和12.37%,子实体多糖和三萜含量比TL-1分别提高1.87%和37.5%,具有较高的应用推广价值。

中草药防治奶牛隐性乳房炎研究进展

奶牛乳房炎是引起奶牛养殖业重大经济损失的三大疾病之一,其发病率高,流行性广泛,危害性极大,可影响奶牛泌乳性能,甚至使乳房丧失机能,严重影响奶牛机体健康及牛奶品质。因此,有效控制奶牛乳房炎,尤其是奶牛隐性乳房炎,对减少经济损失、提高奶牛产奶量及奶品质、促进奶业持续健康发展具有重要的意义。随着人们对食品安全的关注度越来越高,原有的抗生素治疗造成的药物残留和细菌耐药性已经无法符合奶牛业健康发展的需要。中草药来源广泛,资源丰富,具有安全、无残留、低毒性等优点,能够解决世界各国所关注的“有抗奶”问题,甚至可达到治愈隐性乳房炎的目的。因此,本研究阐述了奶牛隐性乳房炎的危害、中草药的作用机制和应用效果及防治奶牛乳房炎的应用前景,为生产实践中奶牛乳房炎的防控提供参考。

建立母乳喂养支持小组对初产妇母乳喂养成功率及持续时间的影响

目的探讨建立母乳喂养支持小组对初产妇母乳喂养成功率及持续时间的影响。方法以2019年3-5月我院产科收治的初产妇80例为对照组,实施常规护理;以2019年6-12月我院产科收治的初产妇235例为研究组,建立母乳喂养小组并实施改进措施。比较两组初产妇母乳喂养成功率、持续时间、涨奶发生率、出院时纯母乳喂养率、产后并发症发生率及满意度。结果与对照组比较,研究组初产妇母乳喂养成功率升高,持续时间延长,涨奶率降低,出院时纯母乳喂养率升高,产妇对护理服务的满意度提高(均P<0.05)。两组初产妇产后并发症发生率比较差异无统计学意义(P>0.05)。结论建立母乳喂养支持小组有助于提高初产妇母乳喂养成功率,延长其持续时间,改善护理满意度,值得推广应用。

基于Karhunen-Loève级数的改进摄动随机有限元法

为了更加准确快捷地对小变异情况下的结构进行随机分析,提出了基于Karhunen-Loève级数的改进摄动随机有限元法(KLSMPSFEM),并给出计算格式。利用Karhunen-Loève(K-L)级数展开法将随机场离散成若干随机变量,并研究了随机场的性质。将得到的随机变量代入改进的摄动随机有限元法进行计算,得到结构响应的二阶估计值,并将KLSMPSFEM与基于K-L级数的蒙特卡洛有限元法(MCM)、基于K-L级数的摄动随机有限元法(PSM)在二维随机场的情况下进行对比。结果表明:KLSMPSFEM的精度要高于PSM,效率要远高于MCM,且能处理一些PSM很难处理的问题。因此该方法是一种兼顾精度与效率的随机有限元法,可广泛应用于多种结构的随机分析。