毛细管微流控芯片器件研究进展

毛细管微流控芯片是微流控芯片领域中重要的一部分,因其具有制备难度低、材料成本低、化学性能优良以及设计灵活的独特优势而得到了广泛的应用与研究。文中对毛细管微流控芯片的基本工作原理与制作方法进行了详细叙述,重点综述了近年来毛细管微流控芯片在液滴生成、纤维纺丝等领域中的研究进展与应用,最后对目前面临的问题进行了探讨,并展望了该技术未来在标准化、高通量及灵活性等方面应用的发展方向。

Associations between parental support for physical activity and moderate-to-vigorous physical activity among Chinese school children： A cross-sectional study

Purpose: The objective of this study was to examine the associations between parental support for physical activity(PA) and levels of moderate-to-vigorous physical activity(MVPA) among Chinese school children.Methods: Study participants were 81,857 school-aged children(aged 9–17 years; mean age = 13 years; 49.0% boys) and their parents or guardians who took part in the 2016 Physical Activity and Fitness in China—The Youth Study project. The independent variables included various forms of parental support for PA ascertained through a survey completed by parents or guardians. The dependent variable was the children's average MVPA in minutes per day by self-report. Structure equation modeling was used to examine the associations between parental support for PA and children's MVPA minutes.Results: The overall mean for MVPA participation time for the child participants was 48.82 ± 28.71 min/day. Significant associations between various forms of parental support and MVPA among children were found. Parental encouragement, accompanying, financial support, involvement,and role modeling for PA were positively associated with a high level of student MVPA participation. Parental PA knowledge-sharing was not associated with MVPA. The patterns of the associations were similar across sex, residence locale(i.e., urban and rural), and school grades(primary,junior middle, and junior high schools).Conclusion: Findings from this study suggest that, among Chinese school children, parental support for PA is important in promoting and facilitating children's participation in MVPA.

Synthesis of hierarchical dendritic micro–nano structure ZnFe_2O_4 and photocatalytic activities for water splitting

Hierarchical dendritic micro–nano structure Zn Fe_2O_4 have been prepared by electrochemical reduction and thermal oxidation method in this work. X-ray diffractometry, Raman spectra and field-emission scanning electron microscopy were used to characterize the crystal structure, size and morphology. The results show that the sample(S-2) is composed of pure ZnFe_2O_4 when the molar ratio of Zn^(2+)/Fe^(2+)in the electrolyte is 0.35. Decreasing the molar ratio of Zn^(2+)/Fe^(2+), the sample(S-1) is composed of ZnFe_2O_4 and α-Fe_2O_3, whereas increasing the molar ratio of Zn^(2+)/Fe^(2+), the sample(S-3) is composed of ZnFe_2O_4 and Zn O. The lattice parameters of ZnFe_2O_4 are influenced by the molar ratio of Zn^(2+)/Fe: Zn at excess decreases the cell volume whereas Fe at excess increases the cell volume of Zn Fe_2O_4. All the samples have the dendritic structure, of which S-2 has micron-sized lush branches with nano-sized leaves. UV–Vis diffuse reflectance spectra were acquired by a spectrophotometer. The absorption edges gradually blue shift with the increase of the molar ratio of Zn^(2+)/Fe^(2+). Photocatalytic activities for water splitting were investigated under Xe light irradiation in an aqueous olution containing 0.1 mol·L^(-1)Na_2S/0.02 mol·L^(-1)Na_2SO_3 in a glass reactor. The relatively highest photocatalytic activity with 1.41 μmol·h-1· 0.02 g^(-1)was achieved by pure ZnFe_2O_4sample(S-2). The photocatalytic activity of the mixture phase of Zn Fe_2O_4 and α-Fe_2O_3(S-1) is better than ZnF e_2O_4 and ZnO(S-3).

Adsorption Capacity for Phosphorus Comparison among Activated Alumina, Silica Sand and Anthracite Coal

Experimental researches on adsorptive capacity of activated alumina, silica sand and anthracite coal for phosphorus were conducted. Results showed that performances of three filter media were all in line with Langmuir isotherm, and activated alumina adsorptive performance was much better than silica sand and an-thracite coal for phosphorus removal. The adsorptive capacity of activated alumina, silica sand and anthracite coal for phosphorus was 3333μg/g, 49μg/g and 100μg/g respectively. Activated alumina displayed adsorp-tive function well for phosphorus, because its inner porosity, specific surface area and surface isoelectric pH value were all higher than those of other two filter media. While activated alumina was used as filter material in water treatment process, phosphorus would be removed strongly because of adsorptive characteristic of activated alumina.

为期6周的饮食和锻炼干预可改变中国11-13岁肥胖儿童代谢综合症的风险因素（英文）

目的:研究人员进行了一项随机对照实验,验证为期6周的低卡路里摄入和有氧运动干预能否改变中国青春期前的肥胖儿童代谢综合症(Met S)的风险因素。方法:实验对象被随机分到饮食运动组(实验组)和对照组。实验组的对象根据自身基础代谢率的不同,6周内每天摄取的热量为1 600到2 000卡路里不等,并坚持高负荷有氧运动(每周6天,每天2次,每次3 h)。共215名11-13岁的肥胖儿童参加此实验,其中167人(实验组95人,对照组72人)完成此实验。实验前后测量的参数包括:体重、体质指数、腰围、体脂率、血压及其他采自空腹血样的代谢综合症的相关指标(血清胆固醇、甘油三酯、胰岛素、血糖)。结果:与对照组相比,除却男孩的空腹时血脂(p=0.09),实验组的所有指标均显著下降(p<0.05)。结论:为期6周集中饮食和运动干预,有利于改善中国11-13岁肥胖儿童代谢综合症的风险因素。

Research Progress of Grassland Feed-animal Balance at Home and Abroad

Feed-animal balance is the key technique on the grassland ecosystem management,and attracts widespread attention in the world.Many studies have been conducted by former researchers,and most of their efforts were intended to keep the balance of feed-animal.However,there are still much more issue needed to be studied in details on the face of grassland degeneration and animal husbandry sustainable development.The author analyzed the feed-animal balance research progress,including the concept of stocking rate and its practical management techniques,especially on the stocking rate calculation methods.In addition,the social and economy effects on feed-animal balance were also discussed during the progress of improving the development of pastoral economy.In order to achieve feed-animal balance more effectively,it was concluded that the focus must be shift from only on animal number to the grassland quality,and it's necessary to strengthen market tax control.

MIC in Circulating Cooling Water System

MIC is one of the main problems of circulating cooling water system. The direct economic loss by MIC is about 300 to 500 billion dollars. It is good to understand MIC in order to control MIC. Source and species of microorganisms was introduced firstly. There are three kinds of microorganisms in the system, including bacteria, fungi and algae. Species of these microorganisms are shown in the paper. Then, mechanisms of MIC are analysed. Although there is no universal mechanism of MIC, MIC is still mainly an electrochemical corrosion in nature. Meanwhile, the mechanisms on SRB and iron bacteria are introduced in details. At last, several methods of microorganisms control are put forward in the paper.

以提升班组自主管理为导向的质量文化建设

本文介绍和分析了现阶段船舶制造企业班组建设中存在的共性问题。同时经过研究分析并结合企业实际情况,加强了对承揽公司班组质量管理,完善班组建设相关制度,落实质量实名制及质量责任,创新推进质量管理提升,加强班组全面质量管理,提高班组自主管理能力,推动了公司质量文化建设。

Electrocaloric effect in ferroelectric materials:From phase field to first-principles based effective Hamiltonian modeling

Electrocaloric effect(ECE)of ferroelectrics has attracted considerable interest due to its potential application in environmentally friendly solid-state refrigeration.The discovery of giant ECE in ferroelectric thin films has greatly renewed the research activities and significantly stimulated experimental and theoretical investigations.In this review,the recent progress on the theoretical modeling of ECE in ferroelectric and antiferroelectric materials are introduced,which mainly focuses on the phase field modeling and first-principles based effective Hamiltonian method.We firstly provide the theoretical foundation and technique details for each method.Then a comprehensive review on the progress in the application of two methods and the strategies to tune the ECE are presented.Finally,we outline the practical procedure on the development of multi-scale computational method without experiemtal parameters for the screening of optimized electrocaloric materials.

Microbiological Induced Corrosion on Brass in Recycling Cooling Water System Makeup by Reclaimed Water

The impacts of microorganism on brass corrosion were studied in static experiment in this paper. Two main factors, temperature and concentration ratio, were considered. According to the actual operation of recycling cooling water system, four temperatures (15℃, 25℃, 35℃ and 45℃) and four concentration ratios (1, 2.5, 3.5 and 4.5) were selected in the experiment. Corrosion potential, current density, average corrosion rate were measured by time. The results showed that: Microorganism often aggravated corrosion of brass during initial and final stages, but alleviated its corrosion at the middle time. With the extension of time that brass immersed in the solution, the microbes began to intensify the corrosion of the metal. When concentration ratios were 2.5 and 3.5 and temperature was 15℃, microbe promoted brass corrosion obviously and corrosion degrees.

A Novel Extrusion Microns Embossing Method of Polymer Film

A continuous hot embossing method is reported in this paper. The continuous means that the extruder and the hot embossing equipment is used in series, the polymer film is embossed after extrusion immediately. The basic principle of this method, the key design point and the corresponding operate process of the embossing equipment is described in this paper. The polymer diffuser with micro-lens matrix on its surface is designed and the optical properties are simulated. Then, the diffuser is fabricated by the embossing equipment. The optical properties of the diffuser are tested and compared with the results of the simulation to verify the reproducibility of the equipment. By this method, the diffuser with large area can be fabricated with high precision of graphic replication, high efficiency and low cost.

中国地方政府掀起新一轮大项目热潮

虽然中央政府对使用刺激措施来提振经济依然持谨慎态度，但中国各级地方政府却在积极上马大项目，从而加剧了外界对于此类投资大量浪费资本、造成债务规模膨胀的担忧。目前并不清楚这些包括高速公路、地铁在内的各种项目最终将如何获得融资，但地方政府对大投入大项目如此热衷，也表明中央政府想要实现中国经济再平衡、降低对于大型投资计划依赖度的目标并非易事。

具有三明治结构的MXene/聚酰亚胺复合泡沫用于多尺度微波吸收

三维多孔结构可促进电磁波在材料内部的多重反射,是提升微波吸收性能的有效方法.然而,传统的三维多孔结构中,多重反射仅发生在孔内.扩大多重反射的范围应能进一步提升材料的吸收性能.因此,本文开发了一种孔壁为三明治结构的三维多孔复合泡沫,在亚毫米尺度孔和亚微米尺度孔壁中同时发生多重反射,实现多尺度微波吸收.本研究采用聚多巴胺修饰的聚酰亚胺泡沫(PDA@PIF)作为三维多孔骨架,在其孔壁表面负载Ti_(3)C_(2)T_(x).所得的Ti_(3)C_(2)T_(x)@PDA@PIF能够在整个X波段吸收超过90%的入射波.这得益于多尺度多重反射、电导损耗和界面极化.同时,该复合泡沫具有优异的柔性和低密度(~30 mg cm^(-3)).该工作为实现轻质、柔性、宽频的吸波材料提供了一种可行的方法,丰富了电磁防护的有效结构.

Photomediated core modification of diaryl dihydrophenzines through three-component alkylarylation of alkenes toward organocatalyzed ATRP

The design and synthesis of a novel organic photocatalyst(OPC)have attracted broad interest from both the organic chemistry and polymer community.Herein,we presented a visible-light-induced alkylarylation of alkenes strategy for core modification of 5,10-diaryl-5,10-dihydrophenazines(DADHPs)under metal-and additive-free conditions,with the aim to develop powerful photocatalyst for organocatalyzed atom transfer radical polymerization(O-ATRP).Good tolerance for a wide variety of functional groups and affording the corresponding tetrasubstituted products in moderate to good yields were achieved in the batch and flow reactor.The experimental and computational mechanistic study confirmed that DADHPs’radical cations andπ-πstacking interactions played important roles in the alkylarylation of alkenes.A series of the tetrasubstituted DADHPs were directly synthesized from the corresponding noncore-modified phenazines,which were demonstrated to be effective organic photoredox catalysts for O-ATRP.Light responsive nature,controlled polymerization manner,and welldefined poly(methyl methacrylate)were achieved via tetrasubstituted DADHPs mediated O-ATRP.

NUMERICAL MODELING OF BIOMASS GASIFICATION USING COW DUNG AS FEEDSTOCK

In this study,a biomass gasification model was developed and simulated based on Gibbs free energy minimization by using software Aspen Plus.Two reactors,RYIELD and RGIBBS,were moslty used.The biomass feedstock used was cow dung.The model was validated.The composition,H_(2)/CO ratio and low heating value(LHV)of the resulting synthetic gas(also known as syngas)was estimated by changing the operating parameters of gasification temperatures,steam and biomass ratios and pressures.Simulation results showed that increased gasification temperature helped to elevate H_(2) and CO content and H_(2) peaked at 900℃.When steam increased as the gasification agent,H_(2) production increased.However,the steam/biomass(S/B)ratio negatively affected CO and CH4,resulting in lower LHV.The optimal S/B ratio was 1.5.An increase in pressure lead to a decrease in H_(2) and CO content,so the optimal pressure for gasification was 0.1 MPa.

Supplementation of Lycium barbarum residue increases the growth rate of Tan sheep by enhancing their feed intake and regulating their rumen microbiome and metabolome

Lycium barbarum residue(LBR),a by-product of L.barbarum processing,is packed with bioactive components and can be potentially utilized as a feed additive in animal husbandry.However,the fundamental understanding of its effectiveness on livestock animals is still lacking,particularly in ruminants.To explore the effects of LBR on the growth performance,rumen fermentation parameters,ruminal microbes and metabolites of Tan sheep,sixteen fattening rams(aged 4 mon)were fed a basal diet(CON,n=8)or a basal diet supplemented with 5%LBR(LBR,n=8).The experiment lasted for 70 d,with 10 d adaptation period and 60 d treatment period.The results showed that the LBR enhanced the average daily feed intake,average daily gain(P<0.05),and ruminal total volatile fatty acids(P<0.01)while decreasing ammonia-nitrogen concentration and rumen pH value(P<0.05).Additionally,the LBR improved the relative abundances of Prevotella,Succiniclasticum,Ruminococcus,Coprococcus,Selenomonas,and Butyrivibrio(P<0.05)and reduced the relative abundances of Oscillospira and Succinivibrio(P<0.05).The LBR altered the ruminal metabolome(P<0.01)by increasing the abundances of ruminal metabolites involved in amino acids(e.g.,L-proline,L-phenylalanine,L-lysine,and L-tyrosine),pyrimidine metabolism(e.g.,uridine,uracil,and thymidine),and microbial protein synthesis(e.g.,xanthine and hypoxanthine).In conclusion,LBR had positive effects on the growth rate of Tan sheep as well as on rumen fermentation parameters,rumen microbiome and rumen metabolome.

宏观构筑基元表面柔顺性的调控与组装

宏观超分子组装的研究对象是表面修饰有大量超分子识别基团的10μm以上的宏观构筑基元,以及它们之间基于超分子多重相互作用的碰撞、识别和组装的过程,它是超分子化学的新兴研究方向,为体相超分子材料的制备提供了新的思路.宏观构筑基元的表面柔顺性是决定构筑基元间能否通过多重相互作用,增强相互作用,实现组装的关键要素之一.本文从界面间相互作用出发,通过交替层状自组装方法,在刚性聚二甲基硅氧烷(PDMS)构筑基元表面分别构筑不同层数的聚电解质多层膜,以调控宏观构筑基元的表面柔顺性,并研究聚电解质多层膜层数对于宏观构筑基元组装行为的影响.通过研究在水中叠加组装的时间与聚电解质多层膜层数的关系,我们发现当构筑基元表面修饰的聚电解质多层膜层数较少时,经过长时间叠加也不能发生组装;随着构筑基元表面修饰的聚电解质多层膜层数的增加,可以在较短的时间内叠加实现组装.同时对构筑基元之间的相互作用力随时间的变化进行了原位测量,其力值与上述组装行为一致.本工作验证了"具有高柔性表面是宏观超分子组装的设计原则",说明通过调控构筑基元表面柔顺性可以调控其宏观组装行为.

虚拟未建模动态补偿与数据驱动的非线性广义预测控制

针对一类离散时间非线性动态系统,把常规广义预测控制与数据驱动控制相结合、反馈控制与前馈补偿相结合、信号补偿与调节器原理相结合,提出了一种数据与虚拟未建模动态及其增量补偿的非线性广义预测控制方法.推导了闭环系统的输入输出动态方程,并分析了所提控制算法的性能.对比实验的研究体现出本文所提控制算法的优越性和有效性.

A compact fluorescence/circular dichroism dual-modality probe for detection, differentiation, and detoxification of multiple heavy metal ions via bond-cleavage cascade reactions

Selective detection of multiple analytes in a compact design with dual-modality and theranostic features presents great challenges. Herein, we wish to report a coumarin-thiazolidine masked D-penicillamine based dual-modality fluorescent probe COU-DPA-1 for selective detection, differentiation, and detoxification of multiple heavy metal ions(Ag^(+), Hg^(2+), Cu^(2+)). The probe shows divergent fluorescence(FL)/circular dichroism(CD) responses via divergent bond-cleavage cascade reactions(metal ion promoted C-S cleavage and hydrolysis at two distinctive cleavage sites): FL “turn-off” and CD “turn-on” for Ag+(no hydrolysis), FL “turn-on” and CD “turn-off” for Hg^(+)(imine hydrolysis), and FL “self-threshold ratiometric” and CD “turn-off” for excess Cu^(2+)(lactone and imine hydrolysis), providing the first example of a fluorescence/CD dual-modality probe for multiple species with complimentary responses. Moreover, the bond-cleavage cascade reactions also lead to the formation of D-penicillamine heavy metal ion complexes for potential detoxification treatments.