Activity Pattern and Habitat Use of Shorebirds in an Artificial Wetland Complex:A Case Study of Breeding Pied Avocet in the Yellow River Delta,China

With the loss of substantial natural wetlands in coastal zones,artificial wetlands provide alternative habitats for many shorebirds.Scientific management of artificial wetlands used by shorebirds plays an important role in maintaining the stability of shorebird population.Satellite tracking technique can obtain high-precision location information of individuals day and night,providing a good technical support for the study of quantitative relationship between waterfowls and their habitats.In this study,satellite tracking method,Remote Sensing(RS)and Geographic Information System(GIS)technology were used to analyze the activity pattern and habitat utilization characteristics of Pied Avocet during breeding period in an artificial wetland complex in the Yellow River Delta(YRD),China.The results showed that the breeding Pied Avocets had a small range of activity,with a total core and main home range of 33.10 km^(2) and 216.30 km^(2),respectively.This species tended to forage in the pond and salt pan during the day and night,respectively,with an unfixed staying time in the breeding ground.The distance between breeding ground and feeding ground was less than 6 km.It is emphasized that in addition to improving the conditions of the remaining natural habitats,effective managing artificial habitats is a priority for shorebird conservation.This research could provide reference for the management of artificial wetlands in coastal zones and supply technique support for the protection of shorebirds and their habitats,and alleviate human-bird conflicts and sustainable development of coastal zones.

5000 t全回转起重船背拉基座结构设计与优化分析

起重船是海洋工程领域的重要辅助船舶,主起重机为起重船的核心装备,保证其在各工况下安全作业是起重船设计的重中之重。本文以某5000 t起重船为研究对象,为提升该起重船尾吊作业能力并保证安全,在船体主甲板中部位置设置有背拉系固设备,并为保证甲板载货面积不受影响,该设备所在区域甲板开口做下沉式处理。由于系固设备位置特殊,为了避免设备背拉基座及甲板开口区域出现结构型损伤,采用有限元方法针对设备基座在有无总纵弯矩作用下进行强度分析。计算结果表明,在总纵弯矩作用下,船中甲板开口角隅及背拉设备基座加强结构出现明显的应力集中情况。根据有限元结果对该区域结构进行优化设计,优化后整体应力情况得到明显改善,相关内容可为后续相关船型设计提供参考,具有一定的工程参考意义。

MFI分子筛限域Ru催化剂的制备及其丙烷催化燃烧性能

采用原位合成法、浸渍法和沉积沉淀法制备Ru与MFI分子筛结合的3种催化剂,用于丙烷(C_(3)H_(8))的催化氧化活性研究.结果显示,通过原位合成法将Ru限域在MFI分子筛孔道内时,Ru@MFI催化剂展现出最佳的低温C_(3)H_(8)氧化活性,在270℃时达到90%转化率,并表现出卓越的高温热稳定性和抗水性.通过XRD、N_(2)吸脱附、HAADF-STEM以及CO-TPD等表征技术发现,限域在MFI分子筛孔道内部的Ru具有最小的粒径和最高的分散度,增加了活性Ru位点的数量.拉曼和H_(2)-TPR表征结果表明,孔道内的Ru与MFI之间相互作用导致电荷重新分布,增强了还原性能.因此,Ru@MFI催化剂呈现出最优异的C_(3)H_(8)氧化活性.此外,MFI孔道的几何限制作用在高温焙烧过程中维持Ru的稳定性和分散度,有效避免了Ru的聚集,进一步确保了催化剂的高温热稳定性.

磨浆机轴承的故障诊断与失效分析实践

磨浆机是制浆造纸打浆工段的重要设备,其运行效率的高低直接影响着产品的产量和质量。ANDRITZ圆柱磨因其具有低能耗和高能效的特点,得到广泛使用。本文介绍了一次发现磨浆机轴承失效后及时处理的案例,并给出了失效原因分析,为今后的日常维护保养提供宝贵经验。

注塑机抽拉杆的有限元分析及疲劳预测

注塑机抽拉杆结构是一种便于在有限厂房空间内实现更换模具的技术。相比较传统拉杆,由于其受力条件更为复杂,故对其材料的机械强度有更高要求。本文采用Creo Simulate的有限元分析工具分别对常用的31CrMoV9V与42CrMo4V两种材料进行应力和变形分析并对其做出疲劳预测,为实际生产提供相关参考依据。

山药药材质量标准提升研究

目的提升山药药材质量标准。方法按照2020年版《中国药典(一部)》方法,对山药药材粉末进行显微鉴别,采用薄层色谱法对药材进行定性鉴别,并对其中的水分、总灰分、浸出物进行检查。采用高效液相色谱法测定药材中尿囊素含量,色谱柱为CAPCELL PAKC18柱(250 mm×4.6 mm,5μm),流动相为甲醇-0.05%磷酸水溶液(4∶96,V/V),流速为0.4 mL/min,检测波长为210 nm,柱温为25℃,进样量为10μL。结果山药药材粉末显微特征明显。薄层色谱斑点清晰,分离度好。药材水分为10.97%~12.31%,总灰分为3.32%~4.04%,浸出物为11.62%~13.85%。尿囊素进样量在0.12~3.00μg范围内与峰面积线性关系良好(R2=1.0000,n=7);精密度、稳定性、重复性试验结果的RSD均小于1.0%;平均加样回收率为100.69%,RSD为0.62%(n=6)。10批药材样品含量为0.71%~0.79%。结论所建立的方法操作简便,结果准确、可靠,可用于山药药材的质量控制。

Effects of total saponins of Panax notoginseng on immature neuroblasts in the adult olfactory bulb following global cerebral ischemia/reperfusion

The main active components extracted from Panax notoginseng are total saponins. They have been shown to inhibit platelet aggregation, increase cerebral blood flow, improve neurological behavior, decrease infarct volume and promote proliferation and differentiation of neural stem cells in the hippocampus and lateral ventricles. However, there is a lack of studies on whether total saponins of Panax notoginsertg have potential benefits on immature neuroblasts in the olfactory bulb following ischemia and reperfusion. This study established a rat model of global cerebral ischemia and reperfusion using four-vessel occlusion. Rats were administered total sa- ponins of Panax notoginseng at 75 mg/kg intraperitoneally 30 minutes after ischemia then once a day, for either 7 or 14 days. Total saponins of Panax notoginseng enhanced the number of dou- blecortin （DCX）＋ neural progenitor ceils and increased co-localization of DCX with neuronal nuclei and phosphorylated cAMP response element-binding/DCX＋ neural progenitor cells in the olfactory bulb at 7 and 14 days post ischemia. These findings indicate that following global brain ischemia/reperfusion, total saponins of Panax notoginseng promote differentiation of DCX＋ cells expressing immature neuroblasts in the olfactory bulb and the underlying mechanism is related to the activation of the signaling pathway of cyclic adenosine monophosphate response element binding protein.

地下室防水混凝土微膨胀剂的研究与应用

研究针对微膨胀剂在公共建筑地下室防水混凝土中的应用和对其性能的影响进行了分析。研究拟采用试验与理论相结合的方式,对微膨胀剂提高抗渗性能的机理进行深入探究。通过对不同掺量的微膨胀剂进行比较试验,研究了微膨胀剂对混凝土工作、力学和抗渗性能的影响。最终得出,在地下室中加入适量的膨润土,可有效减小混凝土的干缩裂纹,改善其强度、抗渗能力,其对地下室防水混凝土的综合性能有明显的改善。通过进一步优化微膨胀剂的用量,为其在工程中的应用奠定基础。

致密储层压驱焖井阶段渗吸机理分子模拟研究

针对致密储层开发中存在的天然地层能量衰减快、驱替相有效波及体积不足等难题,考虑将压驱与焖井相结合的高效开发技术应用于致密储层.基于分子动力学方法从微观作用力角度分析致密储层压驱渗吸机理,进行致密储层压驱过程溶质动态迁移表征,并从分子尺度对渗吸阶段进行划分.采用分子模拟方法,构建致密储层壁面-油相-驱替相三相体系,分别从体系弛豫特征、浓度分布及扩散能力和介质间相互作用能等方面分析常规水力压裂后常压驱替条件和压驱高压条件渗吸过程特征性差异,从分子尺度阐释致密储层压驱渗吸机理.研究表明:相对于常规压裂后驱替而言,压驱条件下,驱替相分子扩散系数提高20.06%,与孔隙壁面的相互作用能提高2.3倍;驱替相分子吸附层数增加,油相解吸效果更为明显,渗吸换油效率提高38.73%.此外,渗吸效率随储层温度变化的过程存在峰值,具有先上升后降低的特征;且受到壁面润湿性的影响,壁面亲水性越强渗吸效率越高.从分子尺度将焖井渗吸过程划分为3个阶段:水分子优先靠近壁面;驱替相流体与油相分子竞争吸附,将吸附态油相剥离为游离态,使其远离壁面;压驱液溶质分子进入初始油相范围,进一步置换油相,提高渗吸效率.压驱技术高压注入压驱剂可快速补充地层能量,扩大驱替相流体波及体积并提高洗油效率,在二者的协同作用下可大幅度提高渗吸驱油效率.该项研究可为致密储层高效开发提供理论参考.

目标体温管理对体外心肺复苏患者神经功能结局和出院生存率影响的系统评价

目的系统评价目标体温管理对体外心肺复苏(extracorporeal cardiopulmonary resuscitation,ECPR)患者神经功能结局和出院生存率的影响。方法计算机检索PubMed、Cochrane Library、Elsevier、Web of Science、Ovid、中国知网、万方、SinoMed、中华医学期刊全文数据库中关于目标体温管理对ECPR患者结局指标影响的文献,检索时限均从建库至2023年6月1日。严格按照纳入排除标准进行筛选,提取资料,评价文献质量,采用RevMan 5.3软件对纳入研究进行Meta分析。结果共纳入8篇研究,包括3687例ECPR患者。与非目标体温管理组比较,目标体温管理未能显著改善患者神经功能结局(OR=1.37,95%CI 0.89~2.13,P=0.16)和出院生存率(OR=0.98,95%CI 0.82~1.15,P=0.77),且两组出血、下肢缺血、肾损伤和感染等ECMO相关并发症发生率差异无统计学意义(OR=1.24,95%CI 0.91~1.68,P=0.17)。结论目标体温管理对ECPR患者的神经结局和出院生存率无显著改善作用,但不会加重ECMO相关并发症的发生。

Comparison of tumor response following conventional versus drug-eluting bead transarterial chemoembolization in early-and very early-stage hepatocellular carcinoma

Objective:To compare the safety of conventional transarterial chemoembolization(cTACE)vs drug-eluting bead TACE(DEB-TACE)in very early-and early-stage hepatocellular carcinoma(HCC).Methods:Data of patients with early-and very early-stage HCC treated with cTACE or DEB-TACE were evaluated retrospectively in this study.A total of 40 patients were included,20 treated with cTACE and 20 with DEB-TACE.The cTACE and DEB-TACE groups were comprised of 80%and 75%males,while there were 20%females in cTACE group and 25%in Deb-TACE group respectively.The mean age of patients in cTACE group was 57.43+5.6 years,while it was 56.4+5.5 years in DEB-TACE group.All patients had liver status of Child–Pugh Class A and a score≤7 in Child-Pugh class type B in very early-(stage 0)or early-phase(stage A)stages according to the Barcelona Clinic Liver Cancer(BCLC)system.Results:The Child-Pugh class degradation in the cTACE group was slightly higher than that in the DEB-TACE group.Serious complications like peritumoral parenchymal ischemia were observed in 4 patients in the cTACE group and 5 in the DEB-TACE group.Localized bile duct dilation was seen in 2 patients in the cTACE group and 6 in the DEB-TACE group.No significant variation in serious complications between the two groups was established in localized bile duct dilatation.Other minor complications noted were liver failure,liver abscess,liver infarction,acute cholecystitis,biliary tree necrosis,and mortality.Further,no substantial variation in tumor response between the groups was reported immediately and 1-year post-procedural assessment.Conversion rate to other treatment modalities such as surgical resection,radiofrequency ablation(RFA),or swap between cTACE and DEB-TACE was substantially higher in the DEB-TACE group(40%)than in the cTACE group(10%)at the 1-year completion period of the study.Conclusion:In terms of tumor response,the DEB-TACE group showed a better response,to some extent,as an initial therapy for HCC in the early stages as compared to the cTACE group,and DEB-TACE also exhibited better clinical efficacy in patients with HCC.

A Multi-Stage Green Barrier Strategy for the Control of Global SARS-CoV-2 Transmission via Cold Chain Goods

1.The object-to-human transmission route of SARS-CoV-2 At the time of writing,coronavirus disease 2019(COVID-19),which is caused by the severe acute respiratory syndrome coron-avirus 2(SARS-CoV-2),has been a global pandemic for more than a year.As of 22 September 2021,the global cumulative incidence exceeds 229 million cases,and the number of deaths has exceeded 4.75 million[1].The current situation of epidemic prevention and control within the countries around the world can be roughly divided into two stages:the pandemic stage that the United States,the United Kingdom,and India are still experiencing(as of 23 September 2021,newly reported cases in the last 24 h in the United States,United Kingdom,and India are 202840,31095,and 26964,respectively[1]);and the normalized epidemic pre-vention and control stage that countries such as China and New Zealand are currently in.

Macular changes of neuromyelitis optica through spectral-domain optical coherence tomography

AIM： To evaluate the thickness of the retinal layers in the macula using spectral-domain optical coherence tomography（SD-OCT） in patients with neuromyelitis optica（NMO）. METHODS： Spectralis SD-OCT, utilizing automated macular layer segmentation, was performed in 26 NMO patients and 26 healthy controls. Visual function including visual field tests and pattern visual evoked potential were recorded in study subjects.RESULTS： Forty-one eyes from 26 NMO patients and52 eyes from 26 age- and sex-matched healthy controls were included. Besides total macular volume, peri-paipillary retinal nerve fiber layer（RNFL） thickness, the thickness of macular RNFL, ganglion cell layer（GCL） and inner plexiform layer（IPL） were also significantly reduced in NMO patients compared to those inhealthy controls（P 〈0.000）. No differences were found in the thickness of macular inner nuclear layer（INL）, outer plexiform layer（OPL）, and outer nuclear layer（ONL） between the two groups. Reversely, the outer retinal layer（ORL） was shown to be thicker in NMO than controls（P 〈0.05）.Compared with the peri-papillary RNFL thickness, the GCL thickness was demonstrated to correlate with visual function better.CONCLUSION： The study provides in vivo evidence of retinal neural loss in NMO patients and demonstrates abetter structure-function correlation between retinal ganglion cell and visual function than peri-papillary RNFL does. In addition, no evidence of primary neural damage is found. Besides, the photoreceptor cells and retinal pigments epithelial（RPE） cells presumably proliferated in compensation in NMO after retinal neural loss.

Reshapeable,rehealable and recyclable sensor fabricated by direct ink writing of conductive composites based on covalent adaptable network polymers

Covalent adaptable network(CAN)polymers doped with conductive nanoparticles are an ideal candidate to create reshapeable,rehealable,and fully recyclable electronics.On the other hand,3D printing as a deterministic manufacturing method has a significant potential to fabricate electronics with low cost and high design freedom.In this paper,we incorporate a conductive composite consisting of polyimine CAN and multi-wall carbon nanotubes into direct-ink-writing 3D printing to create polymeric sensors with outstanding reshaping,repairing,and recycling capabilities.The developed printable ink exhibits good printability,conductivity,and recyclability.The conductivity of printed polyimine composites is investigated at different temperatures and deformation strain levels.Their shape-reforming and Joule heating-induced interfacial welding effects are demonstrated and characterized.Finally,a temperature sensor is 3D printed with defined patterns of conductive pathways,which can be easily mounted onto 3D surfaces,repaired after damage,and recycled using solvents.The sensing capability of printed sensors is maintained after the repairing and recycling.Overall,the 3D printed reshapeable,rehealable,and recyclable sensors possess complex geometry and extend service life,which assist in the development of polymer-based electronics toward broad and sustainable applications.

The mechanism of hydraulic fracturing assisted oil displacement to enhance oil recovery in low and medium permeability reservoirs

Aiming at the technology of hydraulic fracturing assisted oil displacement which combines hydraulic fracturing,seepage and oil displacement,an experimental system of energy storage and flowback in fracturing assisted oil displacement process has been developed and used to simulate the mechanism of percolation,energy storage,oil displacement and flowback of chemical agents in the whole process.The research shows that in hydraulic fracturing assisted oil displacement,the chemical agent could be directly pushed to the deeper area of the low and medium permeability reservoirs,avoiding the viscosity loss and adhesion retention of chemical agents near the pay zone;in addition,this technology could effectively enlarge the swept volume,improve the oil displacement efficiency,replenish formation energy,gather and exploit the scattered residual oil.For the reservoir with higher permeability,this measure takes effect fast,so to lower cost,and the high pressure hydraulic fracturing assisted oil displacement could be adopted directly.For the reservoir with lower permeability which is difficult to absorb water,hydraulic fracturing assisted oil displacement with surfactant should be adopted to reduce flow resistance of the reservoir and improve the water absorption capacity and development effect of the reservoir.The degree of formation energy deficit was the main factor affecting the effective swept range of chemical agents.Moreover,the larger the formation energy deficit was,the further the seepage distance of chemical agents was,accordingly,the larger the effective swept volume was,and the greater the increase of oil recovery was.Formation energy enhancement was the most important contribution to enhanced oil recovery(EOR),which was the key to EOR by the technology of hydraulic fracturing assisted oil displacement.

Effects of Diet on the Volatile Flavor and Nutritional Ingredients of Common Octopus(Octopus vulgaris)

Cephalopods are important economic shellfish that have been developed extensively in the coastal water of various countries. Octopus vulgaris is a large-scaled economic cephalopod that is mainly cultured in South China. This study explored the effect of different diets on the volatile flavor and nutritional ingredients of O. vulgaris. Four diets were tested in four groups: Group A(fish(Scomberomorus niphonius)), Group B(crab(Helice tridens tientsinensis Rathbun)), Group C(clam(Mactra veneriformis)), and Group D(squid(Loligo japonica)). Octopus muscles were sampled after 36 days of feeding, and volatile flavor substances(VFSs), fatty acids(FAs), and amino acids(AAs) were detected. Results showed that the VFSs, FAs, and AAs of octopus in the four groups were obviously different. The sum of volatile ketones and aldehydes was higher in Group B than in the other groups, which could present much more flavors. All groups were abundant in unsaturated FAs, including eicosapentaenoic acid(EPA) and docosahexaenoic acid(DHA). In terms of content and variety, the FAs in Group B were more beneficial to human health than those in the other groups. The content of each AA in Group B was basically higher than those in the other groups and was significantly higher than that in Group D(P < 0.05). Comparing the VFSs, FAs, and AAs in samples fed with four kinds of diets, the results indicate that using crab to feed O. vulgaris can achieve better effects on volatile flavor and nutritional ingredients.

Deformation and failure behavior of heterogeneous Mg/SiC nanocomposite under compression

The heterogeneous magnesium(Mg) matrix nanocomposite with dispersed soft phase exhibits high strength and toughness. Herein, the deformation behavior and failure process were investigated to reveal the unique mechanical behavior of the heterogeneous microstructure under compression. The extensive plastic deformation is accompanied by the flattening and tilting of the soft phase, inhibiting strain localization and leading to strain hardening. Moreover, a stable crack multiplication process is activated, which endows high damage tolerance to the heterogeneous Mg matrix nanocomposites. The final failure of the composite is caused by crack coalescence in the shear plane along a tortuous path. The presence of dispersed soft phases within the hard matrix induces a noticeable change in mechanical response. Especially,the malleability of the heterogeneous Mg matrix nanocomposite is two and ten times higher than that of pure Mg and the homogeneous Mg matrix nanocomposite, respectively. The current study provides a novel strategy to break the trade-off between strength and toughness in metal matrix nanocomposites.

Venous thromboembolism in patients with COVID-19.A prevalent and a preventable complication of the pandemic

Coronavirus disease 2019 or most commonly known as COVID-19 is a trending global infectious disease which a few months ago was affirmed as a global health emergency or a pandemic by the WHO Emergency Committee.The common symptoms manifested in this pandemic disease are high grade fever,cough,fatigue,shortness of breath and flu like symptom which can evolve into severe respiratory disorders such as pneumonia,acute respiratory distress syndrome(ARDS)and/or end-organ failure.Factors that contribute to the severity or high mortality rate in COVID-19 include old age,comorbidities like hypertension,diabetes,hyperlipidaemia,neutrophilia,and organ and coagulation dysfunction.Disseminated intravascular coagulation and other various coagulopathies including Venous thromboembolism have known to become a major contributing factor to high mortality rate.Venous thromboembolism is a disease which is a combination of deep vein thrombosis and pulmonary embolism.Prophylactic anticoagulation in patients prone to or with a pre-existing history of venous thromboembolism is associated with decreased mortality in severe COVID-19 pneumonia.This review article focuses upon COVID-19 and increased incidence of venous thromboembolism in patients infected by COVID-19 along with the role it has in high mortality rate in COVID-19 patients.

联邦学习中防御投毒攻击的客户端筛选策略

联邦学习是一种解决数据孤岛问题的方法,但随着攻击模型的不断进化,敌手可能在训练过程中注入有害参数,导致模型训练效果下降。为了增强联邦学习模型训练过程的安全性,设计了一种面向联邦学习投毒攻击的客户端筛选策略。在该策略中,利用基于差分隐私指数机制的评分函数来动态更新权重参数。首先,为每个客户端分配一致的权重参数;然后,将每一轮训练的效果作为评估标准进行量化,并将量化结果传递至所构建的更新函数中;接着,服务器根据这些更新后的权重参数,筛选出适合参与本轮训练的客户端,并对这些客户端上传的训练模型进行聚合。整个流程反复进行多轮次,最终得出一个有效可靠的训练模型。最后,通过实验验证了所提策略在面对敌手投毒攻击下的可行性。

耦合高压降吸附作用的压驱非线性渗流模型——以大庆油田中低渗透储层为例

考虑压驱剂在基质内的吸附耗损,提出压驱剂动态饱和吸附量随压差和渗透率变化的表征方法,耦合压驱剂黏度-浓度变化关系,建立考虑高压降吸附作用的压驱非线性渗流模型,并开展了影响因素分析。研究表明:压驱技术补能效果主要受基质渗透率、裂缝长度、压驱剂初始浓度影响,补能效果与基质渗透率、裂缝长度呈正相关,与压驱剂初始浓度呈负相关;高压驱剂初始浓度和注入量有利于提高基质内压驱剂浓度从而增强洗油效率,但较长裂缝不利于保持基质内较高的压驱剂浓度;裂缝长度和泵注排量是影响压驱后基质内流体渗流速度的直接因素,可控制驱替相前缘位置,从而影响压驱波及面积。合理选择上述参数,可有效补充地层能量,扩大压驱剂波及体积,提高压驱采收率,并节约开发成本。