The Effects of Fatigue Cracks on Fastener Loads during Cyclic Loading and on the Stresses Used for Crack Growth Analysis in Classical Linear Elastic Fracture Mechanics Approaches

High strength threaded fasteners are widely used in the aircraft industry, and service experience shows that for structures where shear loading of the joints is significant, like skin splices, fuselage joints or spar caps-web attachments, more cracks are initiated and grow from the edges of the fastener holes than from features like fillets radii and corners or from large access holes. The main causes of this cracking are the stress concentrations introduced by the fastener holes and by the threaded fasteners themselves, with the most common damage site being at the edge of the fastener holes. Intuitively, it is easy to visualize that after the crack initiation, during the growth stages, some of the load transferred initially by the fastener at the cracked hole will decrease, and it will be shed to the adjacent fasteners that will carry higher loads than in uncracked condition. Using currently available computer software, the method presented in this paper provides a relatively quick and quantitatively defined solution to account for the effects of crack length on the fastener loads transfer, and on the far field and bypass loads at each fastener adjacent to the crack. At each location, these variations are determined from the 3-dimensional distribution of stresses in the joint, and accounting for secondary bending effects and fastener tilt. Two cases of a typical skins lap splice with eight fasteners in a two rows configuration loaded in tension are presented and discussed, one representative for wing or fuselage skins configurations, and the second case representative for cost effective laboratory testing. Each case presents five cracking scenarios, with the cracks growing from approx. 0.03 inch to either the free edge, next hole or both simultaneously.

Textile Industry to See Slow Growth Analysis of industrial production activities in the first four months

Textile industry, a major driver of the Chinese economy, has fallen victim to the global credit crisis and weaker demand. In the first two months, the output, sale, investment and export of textile industry grew at a slower pace than last year. But things began to pick up after that as the economy slowly begins to recover since March. Signif icant gains at that time will be hard to come by, and won’t be nearly enough to prevent other sizeable slippage in overall textile and apparel activity.

Textile industry to see slow growth Analysis of industrial production activities in the first eight months

The textile sector,a major driver of the Chinese economy,has fallen victim to the global credit crisis and weaker demand.In the first eight months

Prediction of cavity growth rate during underground coal gasification using multiple regression analysis

During underground coal gasification （UCG）, whereby coal is converted to syngas in situ, a cavity is formed in the coal seam. The cavity growth rate （CGR） or the moving rate of the gasification face is affected by controllable （operation pressure, gasification time, geometry of UCG panel） and uncontrollable （coal seam properties） factors. The CGR is usually predicted by mathematical models and laboratory experiments, which are time consuming, cumbersome and expensive. In this paper, a new simple model for CGR is developed using non-linear regression analysis, based on data from 1 l UCG field trials. The empirical model compares satisfactorily with Perkins model and can reliably predict CGR.

Growth performance of the clam, Meretrix meretrix, breeding-selection populations cultured in different conditions

A breeding-selection program for the clam, Meretrix meretrix, was conducted since 2004. Two of the selec- tion populations were generated with the shell color pattern as an additional selection criterion and named as SP （purple stripes） population and SB （black dots） population. The third-generation SP and SB popula- tions （08G3SP and 08G3SB, respectively） were cultured at two commercial clam farms and a nursery pond and their shell lengths were compared. 08G3SB clams had significantly larger sizes than 08G3SP clams at commercial clam farms （p 〈 0.05）, yet 08G3SB individuals were significantly smaller than 08G3SP individ- uals at the nursery pond （p 〈 0.05）. Then, we examined the growth of the fourth-generation SP and SB populations （10G4SP and 10G4SB, respectively） at a commercial farm, and found that the shell lengths of the 10G4SB clams increased at a significantly higher growth rate than the 10G4SP clams （p 〈 0.05） from May to September, when the water temperature was between 24.2-27.5℃, while 10G4SB lost the growth advantage in the other months. These results indicated that SP and SB populations responded differently to environmental factors, so it is beneficial for the clam farmers to select a suitable population according to the culture environment. Furthermore, a diallel mating of the SB and SP populations was designed to investigate whether their hybrid population would show heterosis. However, the heterosis was not shown in this study, which might result from the slight genetic divergence between SB and SP populations.

TRANSFERABILITY OF TOUGHNESS RESULT TO FRACTURE PERFORMANCE EVALUATION OF WELDED JOINTS CONSIDERING STABLE CRACK GROWTH

The transferability of the toughness results in ductile-brittle transition region for welded cracked specimens is conducted by 3D FE analysis. The fracture toughness Values for the double edge notched tension specimens are predicted effectively from the bend test results based on the local approach considering stable crack growth. It is found that the cell model gives a good description of the stable crack growth behavior, and the local approach is useful for the transferability analysis of fracture toughness results in ductile-brittle transition region.

云南农村居民消费与经济增长的回归分析

居民消费对经济增长具有推动作用,针对云南省农村居民消费需求不足问题,从农村居民收入偏低、消费观念落后、国家对农业补贴有限分析的基础上,积极采取各种有效措施增加农村居民收入、转移农村剩余劳动力、加大对三农的财政转移支付力度、健全社会保障制度等措施,提高农村居民消费需求。

Response of Populus x canescens (Populus tremula x alba) to high concentration of NaCl stress

Populus x canescens was cultivated on solid substrate and treated by salt （150 mM NaCl）. The growth parameters including new leaf formation, height increment, diameter at the base increment, fresh and dry mass of leaf, stem, coarse root, and fine root were determined. The nutrient elements in leaves of samples under salt stress and the control, and the chlorophyll fluorescence of plants separated dark and light, initial fluorescence （Fo）, and maximum fluorescence （Fro） were measured. Results showed that 150 mM NaCI treatment resulted in growth reduction of Populus x canescens. Nutrient element contents in the foliage of plants under salt stress were different from that of control. The foliar N-concentrations of plants under salt stress were not affected. Contents of Na under salt stress were 120 times as much as that under control. However, contents of S, K, P, Ca, Mg, Fe, Mn under salt stress were less than that under control. Salt stress caused damage in the PSII reaction centers, i.e. photo-inhibition couldn＇t be repaired under dark situation. The yield of chlorophyll fluorescence showed that several parameters associated with PSII functions, e.g. Fv/Fo, Fv/Fm were not influenced at the first stage of salt stress treatment. However, after a period of time, PSII functions were significantly inhibited, which led to the decrease of carbon assimilation. These results suggest that salt stress （150 mM NaCl） did not affect photosynthetic chlorophyll fluorescence of Populus x canescens immediately. After four day of salt stress, PSII reaction centres were seriously damaged during photo-inhibition.

SEASONAL RHYTHM OF ABOVEGROUND BIOMASS——THE CALAMAGROSTIS ANGUSTIFOLIAGRASSLAND IN SANJIANG PLAIN

In this paper, the seasonal rhythms of the above grassland biomass of the two main types of the Calamagrostis angustifolia grasslands, the Calamagrostis angustifolia meadow and the Calamagrostis angustifolia + Carex schmidilu swamp meadow, were reported. The simulation technique was employed to described the dynamic process. In the end, the absolute growth rate and the relative growth rate of abovcground biomass of the two communities were approached in the light of the growth analysis method.

Kinematic Analysis of Leaf Growth in Grasses:A Comment on Spatial and Temporal Quantitative Analysis of Cell Division and Elongation Rate in Growing Wheat Leaves under Saline Conditions

Hu and Schmidhalter （2008） conducted a study with wheat seedlings growing in saline and non-stressed （control） conditions with the aim of identifying and quantifying the cellular basis for the reduction in leaf growth. We applaud their goals as salinity is an important issue for plant ecology and food production; however, we have concerns about the methodology used and the subsequent conclusJons that are drawn.

Analysis of the Current Industrial Growth Pattern

The process of economic growth and industrial structure upgrading is essentially a process of the formation and replacement of high growth industries. After steady operations over the past three years, China’s industrial growth structure has undergone significant changes, with a number of industries (automobile, machine-building, real estate and tourism) accelerating to become a major force in fueling national economic growth. Whether or not the high growth of these industries will persist so that they become pillar industries in the new round of growth is the key to determining both the nature and the formation of the engine of the new round of growth.

Estimation of China’s Industry-Level TFP and Analysis of Growth Drivers

By examining how China’s total factor productivity(TFP)evolved over time on the industry level,we can help determine where China should head for in a new era featured by a shift from old to new growth drivers and promote high-quality economic development.Based on consistent and comparable data of input and output,this paper measures total factor productivity on the industry level through growth accounting method and then estimate the overall productivity of the entire economy with aggregate production possibility frontier(APPF)and cross-industry direct aggregation.On this basis,China’s growth drivers are analyzed.Results show that from 1985 to 2015,capital input was the top contributor to China’s economic growth and TFP also played an important role.Up to 70 percent of the aggregate TFP growth could be attributed to increases in industrial TFP,while the remaining 30 percent came from improved cross-industrial resource allocation.

Platelet derived growth factor and basic fibroblast growth factor immunolocalized in proliferative retinal diseases

Objective To study the role of platelet derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) in the development of proliferative vitreoretinopathy (PVR) Methods Immunohistochemical localization was performed on frozen sections of the epiretinal or subretinal membranes from 21 PVR patients using!monoclonal antibodies against PDGF and bFGF and the streptavidin peroxidase system Results PDGF was expressed in 15 of 21 specimens (71 4%), and bFGF was expressed in 14 specimens (66 7%) Different cell density was seen in different types of epiretinal membranes The cell density of vascular membranes induced by PDR and Eales disease was the highest (≥61 cells/field, ×1000); nonvascular membranes induced by PVR or traumatic PVR had moderate cell density (31-60 cells/field); and the macular membrane had the lowest cell density (≤30 cells/field) Conclusion The presents of PDGF and bFGF in PVR tissues suggest that PDGF and bFGF may play an important role in the development of PVR

Causality between energy consumption and GDP in the U.S.： evidence from wavelet analysis

This study investigates the dynamic causal relationship between energy consumption and economic growth in the U.S. at different time scales. The main novelty of the study is that this paper complements the existing studies on the nexus between energy consumption and economic growth by employing the wavelet transfor- mation to obtain different time scales in order to investigate causality between energy consumption and economic growth. This method is first developed by Ramsey and Lampart. Their approach consists of first decomposing the series into time scales by wavelet filters and testing causality of each time scale with the pertinent time scale of the other series separately. The data span from 1973ql to 2012ql on a quarterly basis. The main empirical insight is that the causal relationship is stronger at finer time scales, whereas the relationship is less and less apparent at longer time horizons. The results indicate that energy consump- tion causes economic growth, while the reverse is not true at the original frequency of the data. At the very finest scale the same result arises. However, at coarser scales feedback is observed. In particular, at intermediate time scales the evidence indicates that energy consumption causes economic growth, while the reverse is also true. These empirical findings are expected to be of high importance in terms of the effective design and implementation of energy and environmental policies, especially when a number of countries in the pursuit of high economic growth targets do not pay any serious attention on environmental issues.

ASSOCIATION ANALYSIS OF POLYMORPHISMS IN SIX GENES WITHIN THE GH/IGF-1 AXIS IN PATIENTS WITH IDIOPATHIC SHORT STATURE IN THE CHINESE HAN POPULATION

Objective To investigate relationships of polymorphisms in six genes （ GHR, IGF-1, IGF-1R, IGFBP-3, JAK2, and STAT5b） in the growth hormone （GH）/insulin-like growth factor-1 （IGF-1） axis with idiopathic short stature （ISS） in the Chinese Han population. Methods A case- control study was carried out on a cohort of 198 ISS patients and 306 healthy controls. A total of 106 tagging single nucleotide polymorphisms （tagSNPs） from the six genes were selected from the HapMap （haplotype map of the human genome ） Han Chinese in the Beijing subset. Results of genotyping conducted by high- throughput lllumina GoldenGateTM Assay were analyzed by statistical software. Results Both individual tagSNPs and haplotypes showed an association with 1SS in the Han Chinese population （ P 〈 O. 05 ）. For each single test, both allele and genotype were tested. By allele frequency analysis, six positive SNP sites （ rsNo. 1, rsNo. 2, rsNo. 3, rsNo. 4, rsNo. 5, and rsNo. 6） of 3 genes （ JAK2, 1GF-1R, and GHR） were found having associations with ISS. By genotype frequency analysis, there were significant differences between the patient and control groups in the following SNP sites： 4 sites in JAK2 gene （ rsNo. 1, rsNo. 2, rsNo. 3, and rsNo. 4） and 1 site in GHR gene （ rsNo. 6）. The risk which affected ISS was found related to the JAK2 gene in 4 sites （ increase in rsNo. 1 and decrease in rsNo. 2, rsNo. 3, and rsNo. 4 ） and to the GHR gene in 1 site （decrease in rsNo. 6）. They were four haplotypes in gene of IGF-1R as ＂TGC＂, ＂CGCT＂, ＂TA＂, and ＂ CA＂, one haplotype in IGFBP-3 as ＂TA＂, and one haplotype in JAK2 as ＂CTG＂, which revealed high significance for risks of affecting ISS. At last, multivariate logistic regression analysis of specific site rsNo. 6 of the GHR gene revealed that the serum IGF-1 was related to genotypes AA and AC, with genotype CC as the reference （ P =0. 015）. Conclusion Genetic variances in six genes within the GH/IGF-1 axis may be important etiological factors for ISS in the Chinese Han population.

Physical vapor transport crystal growth of ZnO

Zinc oxide（ZnO） has a wide band gap, high stability and a high thermal operating range that makes it a suitable material as a semiconductor for fabricating light emitting diodes（LEDs） and laser diodes, photodiodes, power diodes and other semiconductor devices. Recently, a new crystal growth for producing ZnO crystal boules was developed, which was physical vapor transport（PVT）, at temperatures exceeding 1500 ？C under a certain system pressure. ZnO crystal wafers in sizes up to 50 mm in diameter were produced. The conditions of ZnO crystal growth, growth rate and the quality of ZnO crystal were analyzed. Results from crystal growth and material characterization are presented and discussed. Our research results suggest that the novel crystal growth technique is a viable production technique for producing ZnO crystals and substrates for semiconductor device applications.

China macroeconomic report 2021:China’s macroeconomy marches towards normalisation

In the year 2021,China’s economy continues to recover and moves towards policy normalisation.This report identifies features indicating the beginning of China’s macroeconomic normalisation,the internal and external pressure it faces,and the supporting policies.Due to the economic recovery and the base effect,China’s real GDP growth rate is projected to reach above 8.0%in 2021,and the quarterly growth rate will drop from 18.3%in Q1 to 5.0%in Q4,showing a declining trend.Based on qualitative assessments and statistical forecasts,this report puts forward some policy suggestions.

A comparison on the phytoremediation ability of triazophos by different macrophytes

The strategy of choosing suitable plants should receive great performance in phytoremediation of surface water polluted by triazophos （O,O-diethyl-O-（1-phenyl- 1,2,4-triazol-3-base） sulfur phosphate, TAP）, which is an organophosphorus pesticide widespread applied for agriculture in China and moderately toxic to higher animal and fish. The tolerance, uptake, transformation and removal of TAP by twelve species of macrophytes were examined in a hydroponic system and a comprehensive score （CS） of five parameters （relative growth rate （RGR）, biomass, root/shoot ratio, removal capacity （RC）, and bio-concentration factor （BCF）） by factor analysis was employed to screen the potential macrophyte species for TAP phytoremediation. The results showed that Thalia dealbata, Cyperus alternifolius, Canna indica and Acorus calamus had higher RGR values, indicating these four species having stronger growth capacity under TAP stress. The higher RC loading in Iris pseudacorus and Cyperus rotundus were 42.11 and 24.63μg/（g fw.day）, respectively. The highest values of BCF occurred in A. calamus （1.17）, and TF occurred in Eichhornia crassipes （2.14）. Biomass and root/shoot ratio of plant showed significant positive correlation with first-order kinetic constant of TAP removal in the hydroponic system, indicating that plant biomass and root system play important roles in remediation of TAP. Five plant species including C. alternifolius, A. calamus, T. dealbata, C. indica and Typha orientalis, which owned higher CS, would be potential species for TAP phytoremediation of contaminated water bodies.

Spectroscopic studies of gel-grown lanthanum malonate crystals

Lanthanum malonate crystals were grown by single tube ionic diffusion through silica gel. The crystallinity of the grown crystals was analyzed by powder X-ray diffraction studies. Fourier transform infrared spectroscopy （FTIR） and fourier transform （FT） Raman studies confirmed the presence of functional groups in the title compound. The optical band gap energy of the material was extracted from diffuse reflectance spectrum.