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Tian‐Hao Tu,Ji-Rui WANG,Jian-Qiang GU,Tian-Qi LI,Kun LV,Guo-Xin ZHOU,Zhi-Hong XU 한국곤충학회 2019 Entomological Research Vol.49 No.2
Due to habitat fragmentation, the loss of species diversity has been extensively studied. On the contrary, the effects of habitat fragmentation on functional diversity is still poorly understood. In the Thousand Island Lake, we conducted studies of insect functional diversity on a set of 29 isolated islands. We used 10 functional diversity indices from three aspects (functional richness, functional evenness and functional divergence) to respectively describe functional diversity of insects on sample islands. We found the following results: (i) The functional indices selected could reflect the functional diversity of sample islands and it is further proved that in general, three components of functional diversity were independent of each other; (ii) Sample islands could be divided into two categories, island JSD and the remaining islands; (iii) Functional richness increased with island area and shape index, but had no significant correlation with isolation. Likewise, both functional evenness and functional divergence had no significant correlation with island attributes. The conclusion to emphasize from our research is that: (i) habitat fragmentation reduced the biological functional diversity to some extent, further demonstrating the importance of habitat continuity in biodiversity protection; and (ii) for functional diversity protection of insects in a fragmented landscape, an island which has high approximate shape index values of at least hundred hectare magnitude order has a critical promoting effect.
Enhancement of Impurity, Machinability and Mechanical Properties in Te-Treated 0Cr18Ni9 Steel
Jian‑bo Xie,Tian Fan,Han Sun,Zhi‑qi Zeng,Jian‑xun Fu 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.6
To enhance the machinability and mechanical properties of 0Cr18Ni9 steel, free-machining element Te was introduced inthis work. By adding various quantities of Te to steel, several machining and tensile tests were carried out. Results show thatwith Te addition of 530 ppm, the number of inclusion sizes below 1 μm disappeared. With raising Te from 360 to 530 ppm,more MnTe–MnS inclusions of 10–40 μm were in spherical shape; above 50 μm2, the ratio of inclusion area at 530 ppmwas greatest among all, and the large-sized inclusions occupied a larger share. Te addition contributed to the surfaces ofmachining steels more smooth. The ultimate tensile strength of steel increased from 399 to 435 MPa. Te resulted in growthof sulfides and improved the machinability of steel.
Parametric Research on Underactuated Tendon-Driven Grasping Mechanism for Space Capture Operation
Jian Tian,Cheng Wei,Min Luo,Ning Wang,Chunlin Tan,Yang Zhao 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.2
Space objects always stay in rotation mode with various nutation according to their different inertia parameters during free flying. It is hard for designing a grasping mechanism to capture a rotating target with unknown velocity and unknown size. An under-actuated tendon-driven grasping mechanism is designed and researched in this paper, and which could handle the uncertainties during the capturing using its structural flexibility and strong adaption to space unknown rotating objects for taking the advantage of under-actuation. The under-actuated grasping mechanism consists of four fingers, and each finger has four joints, but driven by only one tendon and four pre-designed springs, which make it a typical under-actuated mechanism. The partial feedback linearization method is modified for the control with time varying constraints and the parametric design method is proposed to complete the tracking control of multiple joint angle using a single driven tendon, and which is validated by the simulation of the whole capturing procedure.
Jian Tian,Fengqi Yu 한국통신학회 2011 Journal of communications and networks Vol.13 No.4
When wireless channels undergo fast fading, non-coherent frequency shift keying (FSK) (de)modulation schemes may be considered for amplify-and-forward (AF) cooperative com-munications. In this paper, we derive the bit-error-rate perfor-mance of partial non-coherent receiver as a lower bound of the optimal non-coherent receiver for FSK modulated AF cooperative communications. From the simulation and analytical results, it is found that the derived lower bound is very closed to simulation results. This result shows that knowing partial channel state infor-mation may not improve system performance significantly. On the other hand, conventional optimal non-coherent receiver involves complicated integration operation. To address the above complex-ity issue, we also propose a near optimal non-coherent receiver which does not involve integration operation. Simulation results have shown that the performance gap between the proposed near optimal receiver and the optimal receiver is small.
( Jian Tian ),( Kee Do Woo ),( Kwang Jin Lee ),( Yu Yong Chen ) 대한금속재료학회(구 대한금속학회) 2014 대한금속·재료학회지 Vol.52 No.2
The effects of substituting a step quenching process for the traditional water quenching and of adding zirconium into an Al-Mg-Si alloy, were investigated using differential scanning calorimetry (DSC) and transmission electron microscope (TEM), together with a tensile and hardness tester. The results indicated that step quenching and zirconium addition affected the microstructure and mechanical properties significantly. Step quenching at 100 ℃ for the Al-Mg-Si alloy was the optimal choice because it promoted the precipitation of the β′′ phase, afforded the maximum age-hardening response and strength increment, and restrained the negative effect of natural aging. Zirconium addition improved the strength while retaining good plasticity for the precipitation of Al3Zr. Zr partially promoted the precipitation kinetics of the β′′ phase when step quenching was conducted at 50 or 100 ℃. †(Received January 15, 2013)
Association Between MDM2 SNP309 T>G and Risk of Gastric Cancer: A Meta-analysis
Tian, Xin,Tian, Ye,Ma, Ping,Sui, Cheng-Guang,Meng, Fan-Dong,Li, Yan,Fu, Li-Ye,Jiang, Tao,Wang, Yang,Ji, Fu-Jian,Fang, Xue-Dong,Jiang, You-Hong Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.3
Background: As a negative regulator of P53, MDM2 plays an important role in carcinogenesis; a polymorphism in its promoter region. SNP309 T>G, is known to increase the expression of MDM2, thus being considered related to higher susceptibility to neoplasia. However, no agreement has been achieved regarding its effects on gastric cancer. Methods: The present systematic meta-analysis was performed based on comprehensive literature search from Pubmed, Web of science and CBM databases. Results: It was suggested from 6 independent studies that the GG genotype is associated with a significantly increased risk of gastric cancer (Recessive: OR = 1.43, 95% CI = 1.08-1.91, P = 0.013), and subgroup analysis also confirmed the relationship (English publications-recessive model: OR = 1.45, 95% CI = 1.10-1.91, P = 0.009; Studies in China-recessive model: OR = 1.58, 95% CI = 1.08-2.30, P = 0.017). No publication bias was detected. Conclusion: The meta-analysis indicated a significant inverse association between GG genotype carriage and elevated risk of gastric cancer. However, more studies and detailed information are needed to fully address the topic.
Tian, Jian,Zhang, Qi,Yu, Fengqi The Korea Institute of Information and Commucation 2011 Journal of communications and networks Vol.13 No.4
When wireless channels undergo fast fading, non-coherent frequency shift keying (FSK) (de)modulation schemes may be considered for amplify-and-forward (AF) cooperative communications. In this paper, we derive the bit-error-rate performance of partial non-coherent receiver as a lower bound of the optimal non-coherent receiver for FSK modulated AF cooperative communications. From the simulation and analytical results, it is found that the derived lower bound is very closed to simulation results. This result shows that knowing partial channel state information may not improve system performance significantly. On the other hand, conventional optimal non-coherent receiver involves complicated integration operation. To address the above complexity issue, we also propose a near optimal non-coherent receiver which does not involve integration operation. Simulation results have shown that the performance gap between the proposed near optimal receiver and the optimal receiver is small.