Differences in spring precipitation over southern China associated with multiyear La Ni?a events

Composite analyses were performed in this study to reveal the difference in spring precipitation over southern China during multiyear La Ni?a events during 1901 to 2015. It was found that there is significantly below-normal precipitation during the first boreal spring, but above-normal precipitation during the second year. The difference in spring precipitation over southern China is correlative to the variation in western North Pacific anomalous cyclone(WNPC), which can in turn be attributed to the different sea surface temperature anomaly(SSTA) over the Tropical Pacific. The remote forcing of negative SSTA in the equatorial central and eastern Pacific and the local air-sea interaction in the western North Pacific are the usual causes of WNPC formation and maintenance.SSTA in the first spring is stronger than those in the second spring. As a result, the intensity of WNPC in the first year is stronger, which is more likely to reduce the moisture in southern China by changing the moisture transport, leading to prolonged precipitation deficits over southern China. However, the tropical SSTA signals in the second year are too weak to induce the formation and maintenance of WNPC and the below-normal precipitation over southern China. Thus, the variation in tropical SSTA signals between two consecutive springs during multiyear La Ni?a events leads to obvious differences in the spatial pattern of precipitation anomaly in southern China by causing the different WNPC response.

玻璃钢隧道防护门优化分析及安全性评估

通过玻璃钢(FRP)材质的疲劳试验数据,利用单侧容限法拟合出置信度为95%、存活率为97.5%的p-S-N曲线,得出玻璃钢防护门的疲劳极限。使用Box-Behnken(BBD)抽样方法完成了试验设计,建立了防护门的应力幅值和长度、宽度、厚度的二阶多项式,利用二代遗传算法(NSGA-Ⅱ)、粒子群算法(PSO)、二次规划法(NLPQL)3种算法进行多目标优化分析,对防护门的应力幅值和体积进行了优化,结果表明:使用NSGA-Ⅱ算法时体积和应力幅值优化效果最好,体积减小率为13.73%,应力幅值减小率为14.68%。根据优化结果进行仿真验证,仿真结果和优化结果一致,证明了优化结果的有效性。根据BS 7910:2019对优化后含缺陷的防护门进行结构安全性评估,计算结果表明:含裂纹缺陷的玻璃钢防护门满足结构安全性需求,a/c值越小,裂纹在后期扩展中越容易趋近BS 7910:2019中FAD图的临界线。

大伞裙结构对复合绝缘子积污特性的影响

为了探究在不同部位改装大伞裙对复合绝缘子积污特性的影响,以FXBW4-110/100型复合绝缘子为基础原模型,构建3种大伞裙结构模型。采用COMSOL Multiphysic对4种绝缘子模型进行积污特性数值模拟,对比分析其附近流场和电场分布差异,探究其在不同风速、粒径、和电压类型下绝缘子表面的积污规律。结果表明:在适当部位改装大伞裙可以改变复合绝缘子近壁区域的流场分布;当所改装的大伞裙尺寸相对较小且片数较少时,复合绝缘子附近的直流电场强度分布几乎不发生变化;同一污秽颗粒粒径下,随风速的增大,积污量呈上升趋势;直流电压作用下,复合绝缘子始末端改装大伞裙即模型I,在低风速时积污量为原模型的75%~95%,且随着风速的增大,积污量差距先增大后减小;交流电压作用下,模型I的积污量以原模型积污量为基值上下浮动,而模型II和模型III在1~3 m/s时的积污量约为原模型的50%~90%。

物流吊车控制器盖注射模设计

针对物流吊车控制器盖的成型要求,设计了1模1腔的模具结构,模具采用单点潜伏式普通浇口进浇,为缩短普通流道的长度,主流道采用斜热喷嘴装置,模具分2次开模,以驱动动模型芯推出而加大成型塑件的脱模力。经实际生产验证:模具结构紧凑,动作稳定可靠,对类似塑件的成型具有一定的参考作用。

Characterization of two halophilic adenylate cyclases from Thermobifida halotolerans and Haloactinopolyspora alba

Adenylate cyclase(AC)is the key enzyme that catalyzes the formation of cAMP from ATP.In this study,we discovered two novel class Ⅲ ACs with a halophilic property from Thermobifida halotolerans DSM 44931(ThAC)and Haloactinopolyspora alba DSM 45211(HaAC),respectively.The recombinant ThAC and HaAC were expressed in Escherichia coli with molecular weights of 36.1 and 36.0 kDa respectively.The presence of 2500 and 2200 mmol
L^(-1)1 NaCl significantly enhanced the enzyme activities of ThAC and HaAC,with 22-fold and 7.4-fold higher activities compared to those without NaCl,respectively.Several divalent metal ions were found to activate the recombinant ACs to different extents,and the optimal metal ion was Mg^(2+)for both ThAC and HaAC with concentrations of 80 mmol·L^(-1) and 40 mmol·L^(-1) respectively.Purified ThAC and HaAC had the optimal specific activities((4.59±0.35)×10^(4) and(7.76±0.52)×10^(4) U·mg^(-1))and catalytic efficiency(4.47 and 5.30 L·mmol^(-1)·s^(-1))at 45
℃ and 40
℃ respectively,while the optimum pH of both two recombinant ACs was 10.0.This is the first report of the halophilic Class III ACs,which could make new contributions to explore and study ACs for further associated investigations.

Enhanced production of cytidine 5'-monophosphate using biocatalysis of di-enzymes immobilized on amino-functionalized sepharose

Cytidine 5'-monophosphate(5'-CMP)is an essential nucleotide for additives.In this study,enhanced production of 5'-CMP was realized by the transformation of cytidine using co-immobilized di-enzymes,uridine-cytidine kinase(UCK)and acetate kinase(AcK).The immobilization yield of the enzyme had a clear correlation with the surface charges as zeta potential(ξ).Among them,ε-polylysinefunctionalized sepharose(SA-EPL,ξ=9.31 m V)showed high immobilization yield(78.8%),which was4.9-fold than that of nitrilotriacetic acid functionalized sepharose(SA-NTA,ξ=-12.6 m V).The residual activity of affinity co-immobilized enzyme(EPL-Ni/EPL@Ac K-UCK)was higher than 70.6%after recycled 10 times.Thus,this study provides an effective approach for the production of 5'-CMP with the advantages of low adenosine 5'-triphosphate(ATP)consumption,reduced side reactions,and improved reusability by co-immobilized UCK and Ac K on the functionalized Sepharose.

Performance of CMIP6 models in simulating the dynamic sea level:Mean and interannual variance

本研究采用卫星测高数据与第六次国际耦合模式比较计划(CMIP6)海平面动力进行对比,重点针对40S-40N地区的动力海平面(DSL),评估了模式对其平均态与年际变率的综合模拟能力,结果表明,对于DSL平均态的模拟,模式与观测结果非常吻合,模式之间的差异较小.其中,副热带北大西洋是模拟偏差和模式间差异较为显著的区域,对于DSL年际变率的模拟,模式之间保持较高的一致性,但是,模式与观测结果存在明显差异,模式普遍低估了DSL的年际方差;其中,误差大值区域出现在副热带西边界流附近,模式分辨率会影响CMIP6对中小尺度海洋过程的重现能力,这可能是导致CMIP6历史模拟出现误差的原因之一.

体质量增长不良儿童的营养及膳食状况分析

目的调查体质量增长不良的1~3岁儿童的营养及膳食状况,为后期的饮食及营养干预提供依据。方法选取2018年10月至2019年5月首都医科大学附属北京儿童医院保健中心因体质量增长不良而就诊的186例儿童,参照WHO 2006年发布的儿童生长发育标准,按照均值离差法对体质量进行5等级评价,采用24 h膳食回顾法结合3 d膳食日记法进行膳食调查,调查结果与中国居民膳食营养素参考摄入量(2013版)进行比较。结果所调查儿童中,低体质量组30例(16.1%),中下体质量组98例(52.7%),中等体质量组58例(31.2%)。所有儿童肉禽鱼类、蛋类、奶类的摄入量均低于推荐摄入量,以低体质量组和中下体质量组最明显,其中低体质量组儿童肉禽鱼类、蛋类、奶类的摄入量分别占推荐摄入量最低值的20.9%、31.1%、57.7%;能量、蛋白质、锌、铁、维生素A的摄入量均低于推荐摄入量,且不同体质量组间整体比较及组内两两比较,差异均有统计学意义(P<0.05)。结论所调查儿童存在一定程度的营养素摄入不足现象,蛋白质、锌、铁、维生素A的摄入不足最为明显,对这类儿童应重视肉禽鱼类、蛋类、奶类的摄入,平衡膳食结构,避免蛋白质以及微量营养素尤其是锌、铁、维生素A的缺乏。

新型冠状病毒肺炎疫情期间哺乳期产妇心理和生活状态调查

目的调查分析新型冠状病毒流行期间哺乳期产妇的心理状态,分析其影响因素,为采取心理支持及鼓励母乳喂养提供依据。方法选取疫情期间(2020年1月23日至7月31日)在北京市居家且正在进行母乳喂养的产妇为研究对象,问卷调查产妇一般情况、婴儿喂养情况、心理状态、生活情况四个方面,运用描述性分析和Logistic回归模型进行统计分析。结果共2 223名产妇参与了本次调查,产妇平均年龄31.5岁,婴儿平均月龄8.2个月,超过60%的产妇在疫情期间选择了"完全没有"各类消极情绪;14.5%的产妇认为完全无法从容面对疫情,产妇感觉可以从容面对疫情与婴儿月龄、来自丈夫和医院方面的喂养支持有关,其OR值及95%CI分别为0.88(0.76~0.91)、1.36(1.14~1.63)、1.24(1.01~1.82),均P<0.05;9.4%的产妇对疫情感到担忧,该变量与婴儿月龄、母亲受教育年限、母乳喂养论坛/微信群交流有关,其OR值及95%CI分别为1.34(1.13~1.81)、1.23(1.07~1.41)、2.49(1.22~5.08),均P<0.05。结论新型冠状病毒肺炎疫情期间,多数哺乳期产妇未出现明显心理健康问题;母亲是否对疫情感到担忧与其受教育程度及婴儿月龄正相关,疫情期间获得丈夫和医院喂养支持的产妇更能够从容应对疫情。

盐雾环境下瓷及复合绝缘子积污特性模拟研究

盐雾环境下的污秽物具有较高的可溶盐含量,可造成绝缘子绝缘性能下降,进而危及电力系统的安全运行。以XWP2-160型瓷双伞绝缘子和FXBW-110/120-2型复合绝缘子为研究对象,基于场致荷电机理,利用多物理场耦合软件COMSOL对其积污特性进行数值模拟,探索了盐密ESDD的计算方法,并验证了其合理性。利用该方法研究了盐雾环境下风速、雾滴粒径、电压类型对瓷及复合绝缘子积污特性的影响,分析了污秽沿绝缘子伞裙的分布规律。结果表明:复合绝缘子的积污量大于同条件下瓷双伞绝缘子积污量,盐雾环境频发地区可优先考虑瓷双伞绝缘子;直流电压下,瓷及复合绝缘子的积污量增长趋势均与风速、粒径呈正相关;复合绝缘子积污量沿伞裙近似呈U型分布,瓷双伞绝缘子积污量沿伞裙近似呈M型分布,且风速越大分布趋势越明显。

不同环境下光伏组件自然积灰特性模拟

研究光伏组件自然积灰特性,可为光伏组件清灰提供理论指导。以华北电力大学光伏组件系统为研究对象,利用COMSOL软件对其积灰物理模型进行了数值模拟,其模拟与试验结果对比表明:二者变化趋势一致、数量级相同且相对误差在允许范围内,验证了模拟方法的合理性。模拟分析了湿度、污秽浓度、颗粒粒径、风速等因素对光伏组件积灰特性的影响。结果表明:相较于其他因素,湿度变化对光伏组件表面积灰影响较小;在其他条件一定时,光伏组件表面积灰量与污秽浓度呈正相关变化,粒径对污秽颗粒沉积的影响大于风速对污秽颗粒沉积的影响,小风速时加剧光伏组件表面积灰,大风速时则有一定的清洁作用。

简化线热源对ATRT计算土体导热系数的影响——数值模拟研究

不同深度土体的导热系数是精细评价浅层地热能的关键参数,基于内加热光缆的热响应测试(ATRT)是获取原位土体分布式导热系数的有效方式之一。利用有限元数值模拟软件ComsolMultiphysics,建立了二维有限元多孔介质传热模型,探究了U型布设内加热光缆条件下内加热光缆间距对实施ATRT计算导热系数的影响。结果表明:ATRT的热响应过程可以分为3个阶段,分别是光缆影响阶段、回填料影响阶段和土体影响阶段。U型布设光缆会增加土体影响阶段达到稳定时的加热时间,不利于提高ATRT计算导热系数的效率;由于简化计算的影响,U型光缆测试结果计算所得的导热系数在加热初期出现了明显高于土体导热系数的峰值,随着加热时间的增加,U型光缆布设条件下温升速率逐渐接近理想线热源温升速率,计算结果也越接近于真实值,缩小间距可以加速这个过程;随着间距增大,将误差控制在10%以内的建议加热时间将快速增大,故在实际工况中为了提高测试效率应尽量减小U型光缆的布设间距。

Relationship between survivin expression and recurrence,and prognosis in hepatocellular carcinoma

瞄准：在肝细胞学习 apoptosis 蛋白质 survivin 的禁止者的表示癌(HCC ) ，和它与在肝切除术以后的 clinicopathological 因素，房间增长，复发和预后的关联。方法：survivin 和 Ki-67 染色的 Immunohistochemical 被标准 streptavidin-peroxidase 技术在 HCC 的 55 个盒子的石蜡节上执行。结果：在 HCC 的 survivin 的积极的率是 52.7%(29/55 ) 。重要关联与门静脉血栓症和肝内 matastasistic 节点在 survivin 表示之间被发现(P 【 0.05 ) 。在 survivin 积极的 HCC 的周期性的率比在在肝切除术以后的 survivin 否定的 HCC，在有 survivin 积极的肿瘤的病人的 1 年、 3 年的幸存率在有 survivin 否定的肿瘤的病人是比那显著地低的显著地高(58.62 和 10.34% 对 76.92 和 30.77% ， P 【 0.05，木头等级测试) 。在 survivin 积极的 HCC 的增长索引(Ki-67 )(33.83%+/-18.90%) 在 survivin 否定的 HCC 比那显著地高(19.60%+/-19.35%)(P 【 0.05 ) 。结论：Survivin 可以由支持房间增长在 HCC 的前进起一个重要作用，并且可以断然在 HCC 与疾病复发和差的预后的高风险被相关。它的表示可以在肝切除术以后与 HCC 为病人用作一个预示的因素。

Evaluation of the Tropical Variability from the Beijing Climate Center's Real-Time Operational Global Ocean Data Assimilation System

The second-generation Global Ocean Data Assimilation System of the Beijing Climate Center(BCC_GODAS2.0) has been run daily in a pre-operational mode.It spans the period 1990 to the present day.The goal of this paper is to introduce the main components and to evaluate BCC_GODAS2.0 for the user community.BCC_GODAS2.0 consists of an observational data preprocess,ocean data quality control system,a three-dimensional variational(3DVAR) data assimilation,and global ocean circulation model[Modular Ocean Model 4(MOM4)].MOM4 is driven by six-hourly fluxes from the National Centers for Environmental Prediction.Satellite altimetry data,SST,and in-situ temperature and salinity data are assimilated in real time.The monthly results from the BCC_GODAS2.0 reanalysis are compared and assessed with observations for 1990-2011.The climatology of the mixed layer depth of BCC-GODAS2.0 is generally in agreement with that of World Ocean Atlas 2001.The modeled sea level variations in the tropical Pacific are consistent with observations from satellite altimetry on interannual to decadal time scales.Performances in predicting variations in the SST using BCC_GODAS2.0 are evaluated.The standard deviation of the SST in BCC-GODAS2.0 agrees well with observations in the tropical Pacific.BCC-GODAS2.0 is able to capture the main features of E1 Nino Modoki I and Modoki Ⅱ,which have different impacts on rainfall in southern China.In addition,the relationships between the Indian Ocean and the two types of E1 Nino Modoki are also reproduced.

Modified DIX model for ion-exchange equilibrium of L-phenylalanine on a strong cation-exchange resin

L-phenylalanine,one of the nine essential amino acids for the human body,is extensively used as an ingredient in food,pharmaceutical and nutrition industries.A suitable equilibrium model is required for purification of L-phenylalanine based on ion-exchange chromatography.In this work,the equilibrium uptake of L-phenylalanine on a strong acid-cation exchanger SH11 was investigated experimentally and theoretically.A modified Donnan ion-exchange(DIX) model,which takes the activity into account,was established to predict the uptake of L-phenylalanine at various solution pH values.The model parameters including selectivity and mean activity coefficient in the resin phase are presented.The modified DIX model is in good agreement with the experimental data.The optimum operating pH value of 2.0,with the highest L-phenylalanine uptake on the resin,is predicted by the model.This basic information combined with the general mass transfer model will lay the foundation for the prediction of dynamic behavior of fixed bed separation process.

Combination Therapy of Multiple Micro Trauma Technology on Hepatocellular Carcinoma

Objective: To compare efficacy of therapy scheme as Transhepatic Artery Chemoembolization (TACE) + Radiofrequency Ablation (RFA) + Introportal Vein Chemotherapy (PVC) + Percutaneous Ethanol Injection (PEI) therapy (quadruplet group) with TACE + RFA combinational therapy (diad group) in treating hepatocellular carcinoma (HCC). Methods: 25 cases in quadruplet group were treated by TACE for 3 weeks, then by RFA, after 2 months, by PVC + PEI;23 cases in diad group were treated by TACE for 3 weeks and then by PEI. After completion of each treatment course in both groups, Alphafetoprotein (AFP) was tested 2 months later;abdomen colorful doppler, CT and AFP were retested 6 months later. Results: AFP was significantly decreased in 23 cases of quadruplet group and 20 cases of diad group among those with AFP positive results. 6 months later, examinations of CT, colorful Doppler and AFP in two groups showed: quadruplet group has significantly decreased (X2 = 6.81, P 0.01) blood supply of cancer tissue and significantly diminished (X2 = 8.29, P 0.01) tumor size, few cases with AFP elevation (X2 = 5.06, P 0.05);lower 1 year relapse rate and two years mortality than that in diad group (X2 = 5.30, P 0.05). Conclusion: TACE + RFA + PVC + PEI combinational therapy is a safe double intervention treatment for HCC scheme with less side effects, which is better than TACE + PEI scheme in killing remnant tumor and reducing relapse.

Hearing analysis in heterozygous and homozygous klotho gene deficient mice

Objective: To understand the crucial role of the klotho gene in hearing development in mouse models.Methods: PCR was used to identify CBA mice with different genotypes, i.e. WT, heterozygous(klotho +/-)or homozygous(klotho-/-). Mice phenotype and weight were recorded postnatal 25 days(P-25) and auditory brainstem responses(ABR) were used to determine auditory function at P-60.Results: klotho-/-mice tended to have smaller size, lighter weight and higher ABR thresholds at P-60,showing early onset age-related hearing loss(ARHL).Conclusion: Heterozygous and homozygous klotho deficient mice exhibit different degrees of hearing loss at young age, with homozygous mice(klotho-/-) showing more severe hearing loss. Our results indicate that persisted expression of klotho protein in the inner ear may potentially delay the onset of ARHL and play an important role in the protection of auditory function.

Recent advance of chemoenzymatic catalysis for the synthesis of chemicals: Scope and challenge

Chemoenzymatic catalysis can give full play to the advantages of versatile reactivity of chemocatalysis and excellent chemo-,regio-,and stereoselectivities of biocatalysis.These chemoenzymatic methods can not only save resource,cost,and operating time but also reduce the number of reaction steps,and avoid separating unstable intermediates,leading to the generation of more products under greener circumstances and thereby playing an indispensable role in the fields of medicine,materials and fine chemicals.Although incompatible challenges between chemocatalyst and biocatalyst remain,strategies such as biphasic system,artificial metalloenzymes,immobilization or supramolecular host,and protein engineering have been designed to overcome these issues.In this review,chemoenzymatic catalysis according to different chemocatalysis types was classifiably described,and in particular,the classic dynamic kinetic resolutions(DKR)and cofactor regeneration were summarized.Finally,the bottlenecks and development of chemoenzymatic catalysis were summarized,and future development was prospected.

虎地肠溶胶囊结合二丙酸倍氯米松灌肠治疗活动期溃疡性结肠炎的疗效及机制分析

背景溃疡性结肠炎(ulcerative colitis,UC)是临床常见慢性肠道疾病,发病率较高,临床治疗UC主要以糖皮质激素类药物为主,但由于UC病情易反复,治疗效果不佳.虎地肠溶胶囊有清热凉血之功效,可能对治疗UC有一定积极作用.目的探讨虎地肠溶胶囊结合二丙酸倍氯米松灌肠治疗活动期UC的疗效及机制.方法根据随机数表法将2018-01/2019-10期间在我院接受治疗的106例活动期溃疡性结肠炎患者分为对照组(53例)和研究组(53例).对照组采用二丙酸倍氯米松灌肠治疗,研究组采用虎地肠溶胶囊+二丙酸倍氯米松灌肠治疗.对比两组临床疗效、中医证候积分、炎性因子水平、结肠黏膜诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOS)、免疫功能等指标.结果研究组治疗总有效率比对照组高(92.45%vs 77.36%),差异有统计学意义(P<0.05).研究组治疗后症候总积分、CD3+、CD4+、CD4+/CD8+均比对照组高,血清白介素-6、白介素-8、肿瘤坏死因子-α及结肠黏膜iNOS水平均比对照组低,差异均有统计学意义(P<0.05).结论虎地肠溶胶囊结合二丙酸倍氯米松灌肠治疗活动期UC的疗效确切,可明显缓解临床症状,降低机体炎症反应,并可调节结肠黏膜iNOS水平,改善免疫功能.