Crystal Growth of Nitrogenase CrFe Protein and MnFe Protein in Space

Nitrogenase CrFe protein and MnFe protein were purified from a mutant strain UW3 of Azotobacter vinelandii Lipmann grown on a medium containing Cr and Mn, respectively. In order to meet the requirement for crystal growth Of O-2-susceptible proteins including nitrogenase in space, crystallization conditions were optimized for the proteins using a simple and suitable device, as a replacement for the cumbersome anaerobic box (dry box), for anaerobic addition of the protein samples. In all used precipitant and protein solutions added in the simplified plexi glass box, CrFe protein and MnFe protein could be crystallized on the spacecraft in one week by the liquid/liquid diffusion method and vapor diffusion by the sitting drop method, respectively. All formed crystals were single on the spacecraft, but under the same condition twin crystals appeared on the ground. The size of the largest crystal grown in space from CrFe protein was 2-fold larger than that on the ground. But the size of the largest crystal grown in space from MnFe protein was not larger than that on the ground. The difference in crystal growth in space between CrFe protein and MnFe protein could be resulted from the crystallization method, rather than the kind of protein.

Studies on Crystalline Growth of O_2-susceptible Proteins in Space

In order to meet the requirement for crystalline growth of O-2-susceptible proteins in space, crystallization conditions on the earth was optimized for the proteins using a simple and suitable device for anaerobic addition of the protein samples. Nitrogenase is susceptible to O-2. Delta nifZ MoFe protein from a nifZ deleted strain and MnFe protein from mutant strain UW3 grown on a medium containing Mn were crystallized at the first time in the world using an anaerobic device equipped with plastic bags or using a small simplified box, as a replacement for the cumbersome dry box. And the proteins could be also crystallized far from laboratory by sitting-drop method using a much lighter device. It was equipped with a smaller plastic food bag and a first-aid bag filled with Ar, as a substitute for the cumbersome dry box and the Ar cylinder, respectively. The results showed that the device could meet the requirement for studies on crystal growth of the above anaerobic proteins in space.

Effects of different feeding methods and space allowance on the growth performance, individual and social behaviors of Holstein calves

The importance of nutrient provisions and weaning methods for calves has been well established over the past few years,while as increasing interest has focused on contribution of animal behavior and their overall performance in production regimes.The present study investigated the effects of feeding methods and space allowance on growth performance,individual and social behaviors in Holstein calves.Twenty-four Chinese Holstein male and female calves were allocated to either an individual or group of 6 and fed either with a bucket or a teat.Milk replacer,calf starter,and Chinese wildrye were offered during the experiment.A fecal index used in the present study was defined as the total fecal scores/total number of calves in each treatment.The results showed that there was no significant difference among the 4 treatments in terms of feed intake,body weight,average daily gain,and fecal index.For the feeding behaviors,the ingesting milk time and ingesting milk rate were significantly affected by space allowance,while the feeding methods showed a significant influence on the bunting behavior of the calves.There was no significant difference among the 4 treatments in terms of licking fixtures,self-grooming,and lying down behaviors,irrespective of the feeding method or space allowance.However,sucking an empty bucket or the teat was significantly affected by the feeding method.Several selected group behaviors were examined in the present study,and similar values for sniffing the other calves,social grooming,and cross-sucking behaviors were observed.Overall,the present study demonstrated that different feeding methods and space allowances had a significant effect on the feeding behavior of calves,while the feed intake,growth performance,health condition,individual and group social behaviors were not significantly influenced.Furthermore,under intensified production systems,Holstein calves raised in a group may obtain a similar production performance,thus reducing management input and profitability compared with those kept individually.However,there may be competition during the feeding period.

Emittance Growth Caused by the Transverse Nonuniform Space Charge Distributions of Bunched Beam in Linac

The nonlinear space charge effect of bunched beam in linac is one of the im-portant factors that induces the emittance growth due to the conversion of the field en-ergy to kinetic energy.In this paper,the internal field energies associated with sometransverse nonuniform space charge distributions of a bunched beam,such as Gaussiandistribution,waterbag distribution and parabolic distribution,are worked out.And theemittance growth caused by these nonuniformities are obtained.

Application of Organic Growth Views in Residential Spaces

This paper explored relevant contents, methods and comprehensive efficiency of organic growth view in residential spaces based on personal experience, so as to fi gure out a new approach of residential space design with high economic efficiency, participation and sustainable connotations.

Go global to win development space and share growth opportunities

In 2013,President Xi Jinping first proposed the ＂Belt and Road Initiative＂;the First China Textile Industry Go Global Conference was held at the same year.In 2015,National Development and Reform Commission,Ministry of Foreign Affairs and the Ministry of Commerce jointly issued the document of ＂The vision and action to promote the construction of Silk RoadEconomic Belt and 21st Century Maritime Silk Road＂; the Second China Textile Industry Go Global Conference was held at the same year.

Effects of Root-Growing Space on Its Absorbing Characteristics

Influences of root-growing space of maize upon root physiological characteristics, nutrient uptake and crop yields were studied under conditions with and without supply of water and N. Results showed that limitation of the root-growing space greatly affected root growth, decreased total root-absorbing area and TTC-reductive amounts. However, it obviously increased the root active-absorbing area, specific absorbing area(absorbing area per gram root weight)and specific active-absorbing area(actively absorbing area per gram root weight)in addition to promoting the TTC-reductive intensity. This clearly showed that plants were not passively tolerant to stress, but actively regulated their physiological metabolic processes, and strengthened their absorbing ability to increase water and nutrient uptake so that root injury by the environmental stress could be reduced. Supply of water and N stimulated root growth, increased root-absorbing area and activity. promoted nutrient uptake, and therefore increased crop yield and decreased the detrimental effects resulting from the limitation of roots-growing space.

SPACE肽修饰成纤维细胞生长因子21的制备及对小鼠皮肤瘢痕形成的抑制作用

目的:制备SPACE肽修饰的成纤维细胞生长因子21(FGF21-SPACE)并探讨其对小鼠皮肤瘢痕形成的抑制作用。方法:将SPACE肽融合表达于FGF21的羧基端,使用大肠杆菌表达系统获得FGF21-SPACE重组蛋白,并制备相应的卡波姆凝胶制剂,聚丙烯酰胺凝胶电泳(SDS-PAGE)与Western blot鉴定其分子量,对重组蛋白携带的组氨酸(His)标签进行免疫组织化学染色,以检测其透皮能力。皮下注射博来霉素诱导小鼠皮肤瘢痕模型,动物实验分为4组,即对照组、模型组、FGF21组、FGF21-SPACE组。HE与Masson染色检测形态学变化;免疫荧光染色检测CD31、TGF-β1表达;Western blot检测α-SMA、纤连蛋白、胶原蛋白Ⅰ的表达。结果:FGF21与FGF21-SPACE的理论分子量分别为25.54 kD与26.61 kD,与SDS-PAGE及Western blot鉴定结果相一致。涂抹FGF21-SPACE凝胶的皮肤组织His染色强度明显强于FGF21凝胶,而空白凝胶则为阴性染色。与FGF21组相比较,FGF21-SPACE组的真皮厚度与纤维化程度降低,CD31表达升高,TGF-β1、α-SMA、纤连蛋白、胶原蛋白Ⅰ表达降低。结论:FGF21-SPACE重组蛋白具备较好的透皮能力,可以抑制皮肤瘢痕形成,促进血管生成,降低纤维化相关因子的表达,具有较好的应用前景。

A PRIORI ESTIMATES TO THE MAXIMUM MODULUS OF GENERALIZED SOLUTIONS OF A CLASS OF QUASILINEAR ELLIPTIC EQUATIONS WITH ANISOTROPIC GROWTH CONDITIONS

In this paper we give a priori estimates for the maximum modulus of generalizedsolulions of the quasilinear elliplic equations irith anisotropic growth condition.

Growth performance of Avicennia officinalis L. and the effect of spacing on growth and yield of trees planted in the Western coastal belt of Bangladesh

A trial ofAvicennia officinalis L. with five different spacings was conducted in the newly accreted lands along the western coastline （Patuakhali district） of Bangladesh since 1993 to assess growth perform- ance and the effect of spacing on tree growth. Data on tree density, height, diameter, bole height, crown diameter were recorded and ana- lyzed when the stand was 19 years old. Mean height ranged from 12.89-13.52 m and diameter at breast height （dbh） from 26.57-32.16 cm in plots of different spacings. The mean annual height increment ranged from 0,67-0.71 m, mean annual diameter increment from 1.40-1.69 cm and wood volume from 6.02-10.04 m3.ha＇l.al in different treatments. Significantly greater diameter （32.16 cm） and wood volume （10.04 m3.hal.a-1） were obtained with wider （2.13 m × 2.13 m） spacing than with closer spacings. But tree growth was unaffected by other spacings. Growth data were also recorded from other .4. officinalis plantations raised by Forest Department （FD） on different islands in Patuakhali and Bhola districts of Bangladesh. At these sites, mean annual height incre- ment ranged from 0.33-0.62 m, mean annual diameter increment from 0.72-1,37 cm and wood volume from 1.55-5.73 m3·ha-1·a·-1. The growth performance of A. offindicated that the newly aecreted lands along the western shoreline may be suitable for raising Avicennia planta- tions for the enrichment of coastal vegetation.

Materials Experiment on Tiangong-2 Space Laboratory

During the China's Tiangong-2(TG-2) flight mission, the experiments of 18 kinds of material samples were conducted in space by using a Multiple Materials Processing Furnace(MMPF) mounted in the orbital module of the TG-2 space laboratory. After the experiments of 12 kinds of samples of the first and second batches were completed successfully, astronauts packed and brought them back to the ground by ShenzhouII spacecraft. By studying processing and formation on semiconductor and optoelectronics materials, metal alloys and metastable materials, functional single-crystal, micro-and nano-composite materials encapsulated in sample ampoules both in space and on Earth, we expect to explore some physical and chemical processes and mechanism of the materials formation that are normally obscured and therefore are difficult to study quantitatively on the ground due to the gravity-induced convection, to obtain the processing and synthesis technology for preparing high quality materials, and lead to the improvement and development of materials processing techniques on Earth, and also develop the experiment device and comprehensive ability for materials experiment in microgravity environment. This report briefly introduces the main points of each research work and preliminary comparative analysis results of 12 samples carried out by scientists undertaking research task.

INTERFACE MORPHOLOGIES AND MICROSTRUCTURES DURING DENDRITE-TO-CELL TRANSITION AT HIGH GROWTH RATE

The interface morphologies and microstruetures of the directionally solidified Ni-5wt-% Cu alloy during dendrite-to-cell transition at high growth rates have been investigated with a newly developed apparatus for unidirectional solidification with the temperature gradient at the solid/liquid interface higher than 1000 K/cm.The results show that in the vicinity of dendrite-to-cell transition point,the well developed sidebranches become shrivelled with the increase of growth rate and disappear at the dendrite-to-cell transition,and the primary spacing decreases simultaneously.Moreover,the length of mushy zone decreases greatly dur- ing the dendrite-to-cell transition.Cells obtained at high growth rates have very similar morphologies to those at low growth rates,but with much smaller cell spacings and unsmoothed cell walls which may be attributed to the different stability conditions of the cell walls at low and high growth rates respectively.

SPACE MATERIALS SCIENCE

The main studying activities and results on space materials science during 1996-1997 in China were summarized. The typical research subjects are crystal growth from melt, crystal growth from solution, nucleation, undercooling,solidification of alloys and space experimental hardware. They are carried out by the ground-based studies, the short duration microgravity missions and orbital experiments.

面向数字社会的学生社群互动行为分析

命运与共是当今世界的显著标志,人际交往对于社会生产与发展具有重要现实意义。信息技术的发展扩大了学生的成长空间,数字交往成为当代学生主要的人际互动形式,网络社群则成为学生成长的主要空间。然而,这也导致学生直面数字社交带来的交往异化和主体性丢失问题。因此,研究从交往理性的视角构建了数字社会CSS架构,涵盖数字文化(Digital Culture)、主体空间(Individual Space)和社会秩序(Social Order)三个层面,该架构为数字社会成员在新时代的生存发展和社会交往提供了可信机理。基于此架构详细分析了个体面向数字社会所应具备的胜任能力,具体包含数字文化中的工具意识、数字素养和主体效能;主体空间中的自我意识、身份认同和行为约束以及社会秩序中的群体意识、情绪驾驭和社会参与。

地方品质、人力资本积累与城市经济增长

人力资本是促进经济增长的关键因素,是我国经济高质量发展的核心动力。城市通过提升地方品质来增加人力资本积累,对于促进城市经济增长至关重要。本文基于新空间经济学理论,利用全国284个城市2010—2019年的面板数据,从人力资本的需求视角出发,分析地方品质对城市经济增长的影响及作用机制。研究发现,地方品质对城市经济增长存在明显的促进作用,在使用系统GMM和工具变量缓解内生性及多种稳健性检验后,这一结论依然成立。机制分析表明,地方品质能够吸引劳动力流入,特别是高技能劳动力的流入,提高本地区创新型人才的集聚水平,促进城市人力资本积累。异质性分析表明,在城市特征方面,地方品质对大城市或者中心城市经济增长的影响效应更显著;在空间特征方面,地方品质对西部地区城市和国家级城市群内城市经济增长的影响效应更显著。本文从地方品质的视角切入来解释城市经济增长问题,为探讨中国城市高质量发展的新路径提供了经验启示。

Effect of Different Spacing and Urea Application Rates on Fruit Nutrient Composition, Growth and Yield of Tomato in Derived Savannah Vegetation of Kogi State, Nigeria

Experiments were located at Lower Niger River Basin Development Authority, Ejiba and Horticultural Section College of Agriculture, Kabba in 2014 cropping season to investigate the effect of different spacing and urea application rates on fruit nutrient composition, growth and fruit yield of tomato in derived savanna vegetation of Nigeria. Field experiments were arranged in a randomized complete block design in factorial fashion with three replications. The row spacing were 75 × 40 cm (33,333 plant·ha-1, 75 × 50 cm (26,666 plant·ha-1) and 75 × 60 cm (22,222 plant·ha-1) while the urea rates comprised control (0 kg urea·ha-1), 54.3 and 108.6 kg urea·ha-1. Growth and yield parameters taken were as follows: average plant height, stem girth, leaf area (m2) and yield per land area. Data were collected from ten randomly selected plants in each plot. The data were statistically analyzed using GENSTAT. The analysis of variance (ANOVA) was performed to find out the significance of variation among the treatments while the significant difference between mean treatments was separated using least significance Difference at 5% level of probability. The result obtained from this study indicated that urea application and spacing affected significantly growth parameters of tomato and yield per land area. It could be concluded that there was a significant increase in plant height, number of leaves, number of fruits per plant and final fruit weight of tomato as a result of urea fertilizer application at the rate of 108.6 kg urea/ha. However, this was not significantly better than plots with urea application at 54.8 kg/ha in both Ejiba and Kabba. Row spacing of 75 × 50 cm showed better performance in number of fruit and fruit yield per plots. Farmers in Ejiba and Kabba should apply urea at the rate of 54.8 kg per hectare and plant the crop at a row spacing of 75 × 50 cm for optimum yield and for a more profitable production of tomato.

基于人力资本与科技研发双重调节下高等教育集聚对经济增长的影响机理研究

研究基于新地理经济学,利用我国31个省份2009—2020年的面板数据,通过空间杜宾模型实证分析高等教育集聚对经济增长的影响及空间溢出效应。研究发现,我国高等教育集聚与经济发展均呈现出由东向西逐渐减弱的分布特征;高等教育集聚对本地区经济增长有着显著的正向影响,空间溢出效应显著;与人力资本的交互项不显著;与科技研发的交互项对本地区经济增长具有显著正向影响,且空间溢出效应均不显著;人力资本与科技研发对高等教育集聚与经济增长之间的联合调节作用显著,空间溢出效应显著。为此,不仅要提高我国高等教育质量,重视中西部高等教育的发展,还要聚焦人才培养、引进、科技研发,实现人力资本与科技研发的有效结合,发挥高等教育的经济增长效应。

Experimental Study and Numerical Simulation Using Extended Finite Element Method (XFEM) Combined with Cohesive Zone Model (CZM), of Crack Growth Induced by Non-Explosive Expansive Material on Two Neighboring Circular Holes of A Gneiss Rock

The Non-explosive expansion material (NEEM) is a method more environmentally friendly than the harmful conventional rock fracturing techniques. However, it is slower and very costly. Thus, any means of economizing their use is very desirable. This paper investigates the crack growth between two neighboring holes of a gneiss rock internally pressurized by NEEM mixed with water with the aim to evaluate the influence of holes spacing (center-to-center distance), on the initiation and growth of cracks. Field experimental results reveal that crack starts earlier and grows faster with increasing ambient temperature. But when the ambient temperature is above 28°C, the NEEM is “blown out” of the holes. At these ambient temperatures, the surrounding rocks are hot and cannot dissipate efficiently the heat generated by the hydration reaction. The best filling time was found to be in the evening when the daily hot temperature has drooped. The time to first crack increases as hole diameter decreases. The 3D numerical modeling and simulation of crack growth between two neighboring holes internally pressurized by NEEM using ABAQUS (XFEM/CZM) software shows a good agreement with the theoretical and experimental results.

Growth Model of Local Government Websites

To clarify the concept framework to assess web based information systems (WIS) evolution from an information perspective instead of the usual systems perspective, and to seek for in-depth understanding of maturing patterns of WISs based on the framework, several central concepts related to the information aspect of WIS are firstly discussed, then a growth model of local government websites based on a survey study is proposed.

A Statistical Model of Quantitative Relationship between Striation Spacings and Fatigue Crack Growth Rates

Fatigue crack growth experiments were per- formed on A1 alloy LD 10 and Ti-6A1-4V alloy. Fatigue striation spacings and the deviation angles between the direction of micro-crack growth and that of macro-crack growth were quanti- tatively measured on fracture surface using scanning electron microscope. A statistical model of the relationship between striation spacings and fatigue crack propagation rates was developed on the basis of a statistical analysis of the deviation angles, Good agreement between experimental results and theoretical results calculated with the present model was obtained.