Study on the contamination and source of chromium in the sea worm jelly in Xiamen

目的了解厦门市市售土笋冻中铬的污染状况,探讨土笋冻中铬的污染来源及预防措施。方法 2012—2014年在厦门市各采样点随机抽取土笋冻样品81份,虫体样品9份,从宁德地区滩涂海域采集可口革囊星虫、淤泥、海水等环境样品6份,依照GB/T 5009.123—2003《食品中铬的测定》中推荐的石墨炉原子吸收光谱法测定样品中铬的含量。结果 81份土笋冻样品中铬含量范围在0.024~17.6 mg/kg之间,平均值为2.17 mg/kg,中位数为1.33 mg/kg,超标率为42.0%(34/81)。添加明胶加工后导致土笋冻中铬含量从1.33 mg/kg升至5.35 mg/kg。从宁德地区滩涂海域采集的星虫、淤泥、海水样品中铬的含量范围分别为2.67~2.70、68.5~77.9和0.038~0.046 mg/kg。结论厦门市市售土笋冻样品中铬的污染情况较为严重,监管部门须加强对土笋冻的原料、加工、销售过程的监控,保证食品安全。Objective To investigate the chromium contamination of sea worm jelly in Xiamen market and to propose the preventive measures against chromium contamination of sea worm jelly based on analysis of the source.Methods A total of 81 samples of sea worm jelly and 9 samples of polypide were collected in Xiamen market from 2012-2014 and 6 samples of Phascolosoma esculenta,silt and seawater were collected from Ningde.The concentrations of Cr in the samples were determined by graphite furnace atomic absorption spectrometry according to GB/T 5009.123-2003.Results The chromium content of 81 samples were 0.024-17.6 mg/kg,the average content was 2.17 mg/kg,and the median was 1.33 mg/kg.The qualified rate was 58.0%.The concentration of Cr in sea worm jelly was changed from 1.33 to 5.35 mg/kg after adding gelatin.The contents of Cr in the Phascolosoma esculenta,silt and seawater from Ningde area were 2.67-2.70,68.5-77.9,0.038-0.046 mg/kg,respectively.Conclusion The chromium contamination in the sea worm jelly was severely in Xiamen.Supervision and monitoring on the raw materials,production,sales of the sea worm jelly should be strengthened to ensure food safety.福建省卫生计生系统食品污染物及有害因素监测方案(闽卫法监函[2014]128号

玻璃化冷冻和程序化冷冻方法对人类卵母细胞骨架及其发育潜能的影响

目的探讨玻璃化冷冻和程序化冷冻对人卵母细胞纺锤体定位、细胞骨架及其发育潜能的影响。方法将第2日发育为M_II卵母细胞随机分为对照组、程序化冻融组、玻璃化冻融组(解冻0 h、1 h、3 h)。应用液晶偏振光显微镜(Polscope)成像系统观察卵母细胞纺锤体与第一极体(Pb)的夹角、表面积、卵透明带内层光阻值和外层光阻值。采用扫描电子显微镜和透射电子显微镜观察卵母细胞的表面和内部超微结构。统计2种冻融方法对卵母细胞发育潜能的影响。结果对照组、程序化冷冻解冻培养3 h组和玻璃化冷冻解冻后培养0 h、1 h、3 h组中的纺锤体可见率分别为92.4%、56.4%、11.2%、24.8%、61.1%。与程序化冻融组相比,玻璃化冷冻解冻培养3 h后卵母细胞中纺锤体与Pb的夹角更小(37.3°与68°,P=0.023)。对照组、程序化冻融组和玻璃化冻融后培养3 h组中卵母细胞的纺锤体面积、卵透明带内层光阻值和透明带外层光阻值差异无统计学意义(P>0.05)。与程序化冻融组相比,玻璃化冻融后培养3 h组中卵母细胞表面突起丰富,微绒毛形态较为正常,倒伏在细胞表面,卵透明带边界较为清晰,与对照组较为接近。程序化冻融组的正常受精率(65.7%)明显低于对照组(79.2%,P=0.041),而卵裂率和囊胚形成率与对照组和玻璃化冻融组差异无统计学意义(P>0.05)。玻璃化冻融后培养3 h组中正常受精率、卵裂率、囊胚形成率与对照组相比,差异无统计学意义(P>0.05)。结论相比程序化冷冻,玻璃化冷冻对卵母细胞纺锤体和卵透明带的损伤及对卵母细胞的发育潜能的影响都较小,可以作为卵母细胞冷冻的一种有效方法。国家自然科学青年基金(81701419);;国家自然科学基金面上项目(81571418)~

Two-dimensional Model Predictive Iterative Learning Control Scheme Based on a Two-dimensional Performance Model

将迭代学习控制(ITErATIVE lEArnIng COnTrOl,IlC)系统看作一类具有2维动态特性的控制系统,根据模型预测控制(MOdEl PrEdICTIVE COnTrOl,MPC)和性能参考模型控制思想,提出了一种基于2维性能参考模型的2维模型预测迭代学习控制系统设计方案.在该控制系统设计方案中,可以通过选择适当的2维性能参考模型来构造2维动态变化的设定值信号和预测控制信号,从而引导迭代学习控制系统收敛到合理的控制性能,并有效避免系统性能收敛过程中控制输入可能发生的剧烈波动.通过对控制系统的结构分析可知,所得的迭代学习控制器本质上是由沿时间指标的参考模型预测控制器和沿周期指标的迭代学习控制器组成,闭环系统的收敛性等价于一个2维滤波系统的稳定性.数值仿真结果证明了该设计方案的有效性和鲁棒性.By representing an iterative learning control(ILC) system as a two-dimensional system and using the philosophy of model predictive control(MPC) and performance model reference control,a two-dimensional performance model based model predictive iterative learning control scheme is proposed in this paper.Through the design of two-dimensional dynamics of the performance model to generate more proper reference trajectories and predictive control signals for each cycle,the convergence pattern of the iterative learning control system can be guided to avoid the issue of possibly violent oscillation of input signal.The structure analysis indicates that the resulted control is composed of the time-wise performance model based model predictive control and cycle-wise iterative learning control,and that the convergence of the closed loop control system is equivalent to the stability of a two-dimensional filter.Numerical simulations illustrate the effectiveness and robustness of the proposed control scheme.国家自然科学基金(61174093)资助~

Fabrication and bacterial adhesion of metal dry electrode with surface microstructure arrays

为开发出高性能生物医用干式电极,提出了利用激光微铣-重铸加工方法,实现了表面具有微结构阵列特征的新型金属干式电极的制造成形。在分析电极表面微观形; 貌的基础上,研究了电极表面的润湿性能,并重点研究了扫描间距、扫描速度和扫描次数等加工参数对大肠杆菌粘附性能的影响规律。研究结果表明:在一定工艺参; 数条件下所加工出具有微结构阵列特征的电极的接触角可达150°以上,表现出超疏水的特性。在不同扫描间隙和扫描次数条件下加工出的电极对大肠杆菌的粘附; 性能具有较大影响,在选择0.1; mm扫描间隙时,电极表面粘附的大肠杆菌数量最少,适当增加扫描次数,也能够有效地减少电极表面大肠杆菌的粘结,从而发挥较好的抗菌效果。通过改变扫描速; 度加工出的电极则对大肠杆菌的粘附性能影响不大。To develop a high performance biomedical dry electrode, the laser; micromilling-recasting technology is used to fabricate the metal dry; electrode with surface micostructure arrays. Based on the analysis of; the micro morphology of the electrode surface, the wettability of the; electrode surface is discussed, and then the influence of laser; processing parameters such as scanning spacing, scanning speed and scan; times on the adhesion performance of Escherichia coli is further; investigated. The results show that the contact angle of metal dry; electrode with surface microstructure arrays fabricated with reasonable; laser processing parameter can reach more than 150° and show the; superhydrophobic characteristics. The adhesion performance of; escherichia coli of electrode is changed greatly with different scanning; spacing and scan times. When the 0.1 mm scanning spacing is selected,; the least amount of escherichia coli is found on the surface of; electrode. With the increasing scan times, the adhesion amount of; escherichia coli can be reduced. However, the scanned speed has little; effect on the adhesion performance of escherichia coli for metal dry; electrode.国家自然科学基金面上项目; 厦门市科技计划项目; 厦门市科技惠民项

中药沐足结合护理干预治疗护理人员下肢静脉曲张的效果观察

目的探讨中药沐足结合护理干预在下肢静脉曲张护士中的应用效果。方法选取某三甲综合性医院患有下肢静脉曲张的临床护士60例为研究对象,应用随机数字表法分为两组,各30例。两组研究对象均行基础护理,对照组采用医用的循序减压弹力袜进行治疗,观察组实施中药沐足结合护理干预措施。2个月后比较两组患者疗效。结果观察组研究对象静脉曲张恢复总有效率高于对照组,观察组研究对象经过3个疗程的治疗,痊愈12例,显效l3例,有效4例;对照组分别为痊愈5例,显效8例,有效9例;观察组、对照组临床治愈率和总有效率分别为40.00%、96.67%和16.67%、73.33%。差异有统计学意义(P<0.05)。结论中药沐足结合护理干预可以改善下肢静脉曲张的临床症状。福建中医药大学2016年临床专项校管课题(XB2016085

Development of a New Temperature and Humidity Sensitive Integrated Sensor

研制成由硅温敏二极管和聚酸亚胺湿敏电容集成的温湿度传感器。介绍了它的工作原理、结构设计、制作工艺、测试结果以及为提高它的性能所作的一些研究。An integrated temperature and humidity sensor consisting of the silicon diode and the polyimide-based capacitive humidity sensor has been deve-loped.The sensor working principle, structure design, manufacturing technology, measurement results and some studies of improving the sensor characteristics have been introduced.福建省科技资

Structural Recombination of Polymethylsilicone Induced by Laser Plasma

[中文文摘]将脉冲激光束在惰性气氛中溅射石墨产生的等离子体,与一维链状聚甲基硅氧烷的蒸气束流反应 ,在产物中通过真空升华和重结晶分离出了两种单晶,经X射线衍射测定为具有 (CH3SiO1.5) n(n =8,10 )组成的硅氧烷,它们均具有多面体的三维笼状构型 .通过色 -质联用还检测到其它硅氧烷化合物,其中某些产物已表征为二维多环的构型.反应结果表明,经由激光等离子体的碰撞和能量传递,反应物的链状结构发生解离和进一步反应,经结构重组形成了多种不同组成和构型的产物。[英文文摘]A special synthetic reaction has been developed, in which vapor of the reactant interacts with the high temperature plasma generated by laser ablating a graphite target. By selecting chained methylsilicone as reactant, a series of methylsilsesquioxanes products with various structural configurations have been obtained. Among them, two products, which were separated by sublimation in high vacuum and recrystalization, were characterized by X-ray crystal diffraction as (CH_3SiO_ 1.5)_n (n=8,10). Both of them are found to have three-dimensional cage structure.In addition,other products with double ring structure were detected by GC-MS analysis.The results demonstrate the potential application of the synthetic reaction.In the reaction described in this article,resulting from the collision and energy-transfer of the laser plasma,chain structure of the reactant dissociated and recombined to give the cage and ring structure of the product.国家自然科学基金重大项目(29890210)资助课

Solid and solution structural studies of dimeric and tetrameric molybdenum(VI) malate complexes

Reactions of potassium molybdate with racemic malic acid (H(3)mal = C4H6O5) result in the isolation of two mesomeric molybdenum malate complexes K-8[(MoO2)(2)O(R-mal)(2)][(MoO2)(2)O(S-mal)(2)]center dot 4H(2)O 1 and (HiM)(2)K-6[(MoO2)(4)O-3(R-mal)(2)][(MoO2)(4)O-3(S-mal)(2)]center dot 8H(2)O 2. Complex 1 belongs to the monoclinic system, space group C2/c with a 14.8637(3), b = 6.9544(1), c = 19.6783(5) angstrom, beta = 100.08](2)degrees, V = 2002.70(7) angstrom(3), M-r = 1452.88, Z = 2, F(000) = 1416, T = 173 K, D-c = 2.409 g/cm(3), mu(MoK alpha) = 2.167, R = 0.0283 and wR = 0.0733. 2 is of triclinic system, space group P (1) over bar with a = 8.7707(2), b = 9.3310(3), c = 17.9093(7) angstrom, alpha = 83.781(3), beta = 85.626(2), gamma = 84.822(2)degrees, V = 1447.84(8) angstrom(3), M-r = 2160.68, Z = 1, F(000) = 1048, T = 173 K, D-c = 2.478 g/cm(3), mu(MoK alpha) = 2.230, R = 0.0234 and wR = 0.0584. 1 is the first isolated dinuclear molybdenum(VI) malato complex in 1: 1 molar ratio. The molybdenum atoms in the two complexes are six-coordinated in an approximately octahedral geometry. Two malates coordinate tridentately with the Mo atom via their alpha-alkoxy, alpha-carboxy and alpha-carboxy groups in 1and 2. beta-Carboxy group in 2 further links with the other two Mo atoms to give a tetrameric unit. The solution I H and C-13 NMR spectra indicate that dimeric malate molybdenum in I dissociates partly in solution and exists in an equilibrium with tetrameric species, while 2 is stable and retains its tetrameric structure without any dissociation

Plenty is Plague: Fine-Grained Learning for Visual Question Answering

纪荣嵘教授团队的论文提出了一种基于强化学习的细粒度学习策略FG-A1C，旨在通过分析视觉问答任务中的样本多样性及标签的冗余性问题来针对性地挑选训练样本以提高模型的训练效率及减少标记支出。 该论文由厦门大学媒体分析与计算实验室的周奕毅博士后助理研究员、纪荣嵘教授（通信作者）、孙晓帅副教授、苏劲松副教授，以及西安交通大学孟德宇教授、清华大学高跃副教授和澳大利亚阿德莱德大学沈春华教授等合作完成。Visual Question Answering (VQA) has attracted extensive research focus recently. Along with the ever-increasing data scale and model complexity, the enormous training cost has become an emerging challenge for VQA. In this paper, we show such a massive training cost is indeed plague. In contrast, a fine-grained design of the learning paradigm can be extremely beneficial in terms of both training efficiency and model accuracy. In particular, we argue that there exist two essential and unexplored issues in the existing VQA training paradigm that randomly samples data in each epoch, namely, the "difficulty diversity" and the "label redundancy". Concretely, "difficulty diversity" refers to the varying difficulty levels of different question types, while "label redundancy" refers to the redundant and noisy labels contained in individual question type. To tackle these two issues, in this paper we propose a fine-grained VQA learning paradigm with an actor-critic based learning agent, termed FG-A1C. Instead of using all training data from scratch, FG-A1C includes a learning agent that adaptively and intelligently schedules the most difficult question types in each training epoch. Subsequently, two curriculum learning based schemes are further designed to identify the most useful data to be learned within each inidividual question type. We conduct extensive experiments on the VQA2.0 and VQA-CP v2 datasets, which demonstrate the significant benefits of our approach. For instance, on VQA-CP v2, with less than 75% of the training data, our learning paradigms can help the model achieves better performance than using the whole dataset. Meanwhile, we also shows the effectivenesss of our method in guiding data labeling. Finally, the proposed paradigm can be seamlessly integrated with any cutting-edge VQA models, without modifying their structures.This work is supported by the National Key R&D Program (No.2017YFC0113000, and No.2016YFB1001503), Nature Sci- ence Foundation of China (No.U1705262, No.61772443, and No.61572410), Post Doctoral Innovative Talent Support Pro-gram under Grant BX201600094, China Post-Doctoral Sci- ence Foundation under Grant 2017M612134, Scientific Re-search Project of National Language Committee of China (Grant No. YB135-49), and Nature Science Foundation of Fu-jian Province, China (No. 2017J01125 and No. 2018J01106). 本项研究得到了厦门大学“人工智能分析引擎”双一流重大专项的支持、国家重点研发专项和国家自然科学基金海峡基金等项目的支持

Catalytic Effect of Cl~- on Electrodeposition of Binary Zinc Alloys With Iron group Metals

在氯化物电解液中以定电量 (10C cm- 2 ) ,恒温 4 0℃电沉积Zn Fe族元素二元合金 .沉积产物用原子吸收光谱分析 .根据分析结果 ,作出相应的电流效率、百分含量及部分极化曲线 .镀层形貌采用扫描电镜 (SEM)观察 ,发现 :Zn Fe族元素合金的共沉积为异常共沉积 .Cl- 对铁族元素有催化作用 .随着Cl- 浓度的增加 ,降低了铁族元素的过电位 ,促进了铁族元素金属的沉积 .Zinc iron group metal alloys were deposited under coulostatic (10C.cm -2 ) at 40 ℃ chloride baths. The deposited alloys were quantitatively analyzed by Atomic Absorption Spectrometry. The current efficiency, percent content and partial polarization curves were obtained by the results. The morphology of the deposits was observed by means of Scanning Electron Microscopy(SEM). We observe that the electrodeposition of zinc iron group metal alloys is one of the best known examples of anomalous codeposition. We found the catalytic effect of Cl - on the electrodeposition behavior of iron group metal. Overpotential of iron group metal droped abruptly at high Cl - concentration, while transition current density of Zn increased gradually.作者联系地址：上海大学理学院化学系!上海宝山,200436,上海大学理学院化学系!上海宝山,200436,上海大学理学院化学系!上海宝山,200436,上海大学理学院化学系!上海宝山,200436,上海大学理学院化学系!上海宝山,200436Author's Address: Shanghai Univ., Shanghai Bao shan, 200436,Chin