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| 1 | Linking atmospheric pollution to cryospheric change in the Third Pole region: current progress and future prospects显示文摘The Tibetan Plateau and its surroundings are known as the Third Pole(TP). This region is noted for its high rates of glacier melt and the associated hydrological shifts that affect water supplies in Asia. Atmospheric pollutants contribute to climatic and cryospheric changes through their effects on solar radiation and the albedos of snow and ice surfaces; moreover, the behavior and fates within the cryosphere and environmental impacts of environmental pollutants are topics of increasing concern. In this review, we introduce a coordinated monitoring and research framework and network to link atmospheric pollution and cryospheric changes(APCC) within the TP region. We then provide an up-to-date summary of progress and achievements related to the APCC research framework, including aspects of atmospheric pollution’s composition and concentration, spatial and temporal variations, trans-boundary transport pathways and mechanisms, and effects on the warming of atmosphere and changing in Indian monsoon, as well as melting of glacier and snow cover. We highlight that exogenous air pollutants can enter into the TP’s environments and cause great impacts on regional climatic and environmental changes. At last, we propose future research priorities and map out an extended program at the global scale. The ongoing monitoring activities and research facilitate comprehensive studies of atmosphere–cryosphere interactions, represent one of China’s key research expeditions to the TP and the polar regions and contribute to the global perspective of earth system science. | Shichang Kang Qianggong Zhang Yun Qian Zhenming Ji Chaoliu Li Zhiyuan Cong Yulan Zhang Junming Guo Wentao Du Jie Huang Qinglong You Arnico K.Panday Maheswar Rupakheti Deliang Chen Orjan Gustafsson Mark H.Thiemens Dahe Qin | 2019 | National Science Review2019,6,4: | 35 |
| 2 | The discovery of Palaeoproterozoic volcanic rocks in the Bulunkuoler Group from the Tianshuihai Massif in Xinjiang of Northwest China and its geological significance显示文摘In the Dabudaer region of the Tianshuihai Massif (Xinjiang, Northwest China), metavolcanic rocks within the mainly meta-sedimentary Bulunkuoler Group are basalt, basaltic andesite, and rhyolite. In situ zircon U-Pb LA-ICP-MS dating on rhyolite magmatic zircons yielded an age of 2481±14 Ma, interpreted as the eruption age of the Bulunkuoler Group volcanic rocks. The basalt and basaltic andesite are low-Al tholeiite series and the rhyolite is low-Al calc-alkaline series. All of rocks are charac-terized by enrichment of LREE and LILE (Rb, Th and Ba), depletion of P, Nb, Ta and Ti, and absence of Eu anomalies. The εNd(t) of basalts ranges from 3.14 to 4.88 indicating a depleted mantle source. The trace element signatures show that these magmas experienced intense crustal contamination during their ascent. Direct evidence for crustal contamination is the xenocrystic zircons in the ryholite, with ages back to ca. 3300 Ma. The primitive-mantle normalized and Zr/Y-Zr diagrams for the basic volcanic rocks show that they formed in an intra-continental tectonic setting. Combined with the previous studies and compared with North China Craton Neoarchean basic volcanic rocks, it is supposed that the Bulunkuoler Group volcanic rocks reflect the Palaeoproterozoic mantle magma underplating and interaction with felsic crust. | JI WenHua LI RongShe CHEN ShouJian HE ShiPing ZHAO ZhenMing BIAN XiaoWei ZHU HaiPing CUI JiGang REN JuanGang | 2011 | Science China Earth Sciences2011,54,1: | 22 |
| 3 | Hermetia illucens larvae as a potential dietary protein source altered the microbiota and modulated mucosal immune status in the colon of finishing pigs显示文摘Background: Insects, such as Hermetia illucens larvae, are rich in chitin and proteins, and represent a suitable feed ingredient replacement for animals. However, little is known about the effect of administering H. illucens larvae on intestinal microbiota, bacterial metabolite profiles, and mucosal immune status in animals. This study aimed to investigate the effects of administering H. illucens larvae on colonic microbiota and bacterial metabolites production in finishing pigs. Seventy-two crossbred(Duroc × Landrace × Large White) female pigs(initial body weight, 76.0 ± 0.52 kg) were randomly allocated to three different dietary treatments: a control diet(Control group) and two diets corresponding to 4%(H1 group) and 8%(H2 group) H. illucens larvae inclusion levels, respectively. Each treatment consisted of eight pens(replicates), with three pigs per pen. After 46 days of feeding, eight pigs per treatment(n =8) were slaughtered, and the colonic digesta and mucosa were collected for microbial composition and microbial fermentation products, and genes expression analyses.Results: The results showed that the H1 diet significantly increased the abundance of Lactobacillus,Pseudobutyrivibrio, Roseburia, and Faecalibacterium compared with those in the control group(P < 0.05), with a decrease in the abundance of Streptococcus. The numbers of Lactobacillus, Roseburia, and Clostridium cluster XIVa were significantly greater in the H1 group than in the control group(P < 0.05). Meanwhile, H2 diet increased the number of Clostridium cluster XIVa compared with the control group(P < 0.05). For colonic metabolites, total short chain fatty acids, butyrate, and isobutyrate concentrations were significantly higher in the H1 group than those in the control group(P < 0.05);the H1 treatment caused a striking decrease in protein fermentation compared with the control group, as the concentrations of total amines, cadaverine, tryptamine, phenol, p-cresol, and skatole were significantly lower(P < 0.05). Additionally, H2 diet also increased butyrate concentration compared with control group(P < 0.05), while decreased the concentrations of phenol, p-cresol, and skatole(P < 0.05). Pigs in the H1 group down-regulated the expression of TLR-4 and pro-inflammatory cytokines(IFN-γ) compared with pigs in the control group(P < 0.05), and up-regulated anti-inflammatory cytokine(IL-10) and intestinal barrier genes(ZO-1, occludin, and mucin-1). H2 diet up-regulated the expression of ZO-1 compared with control group(P < 0.05). Furthermore, the changes in the colonic mucosal gene expression were associated with changes in the bacterial composition and their metabolites.Conclusions: Collectively, dietary inclusion of Hermetia illucens larvae may enhance mucosal immune homeostasis of pigs via altering bacterial composition and their metabolites. These findings provide a new perspective on insect meal as a sustainable protein source rich in nutrient ingredients for swine. | Miao Yu Zhenming Li Weidong Chen Ting Rong Gang Wang Xianyong Ma | 2019 | Journal of Animal Science and Biotechnology2019,10,4: | 21 |
| 4 | Different dietary starch sources alter the carcass traits, meat quality, and the profile of muscle amino acid and fatty acid in finishing pigs显示文摘Background: With increasing health awareness among consumers, the demand for healthier, tastier, higher quality and nutritional value pork is increasing. It has been shown that different dietary starch sources can alter the carcass traits and meat quality. However, research on the effects of different starch sources with clear different amylose/amylopectin ratio on the amino acid and fatty acid composition in Longissimus thoracis(L. thoracis) muscle of pigs is limited. This study aimed to investigate the effects of different dietary starch sources on carcass traits, meat quality, muscle amino acid and fatty acid composition, and the mRNA expression levels of genes involved in lipid metabolism and muscle fiber characteristics in finishing pigs. A total of 72 Duroc × Landrace × Large White barrows were randomly allocated to 3 different dietary treatment groups with 8 replicate pens/group and 3 pigs per pen.Tapioca starch(TS), corn starch(CS), and pea starch(PS), with amylose/amylopectin ratio of 0.11, 0.25, and 0.44,respectively, were used as their dietary starch sources for 40 days.Results: Results showed that the PS diet significantly increased(P < 0.05) the final body weight, average daily gain,loin-eye area, and fat-free lean index compared with the TS diet, but significantly decreased(P < 0.05) the feed to gain ratio and backfat thickness. Compared with the TS diet, PS diet also increased(P < 0.05) the pH45 min, marbling scores, the content of intramuscular fat and inosine monophosphate in the L. thoracis, and decreased(P < 0.05) the drip loss and shear force. In addition, compared with the TS diet, PS diet increased(P < 0.05) the proportions of flavor amino acids, DHA, EPA, and n-3 polyunsaturated fatty acid(PUFA) in the L. thoracis compared with TS diet,but decreased(P < 0.05) the ratio of n-6/n-3 PUFA. Furthermore, compared with the TS diet, PS diet also upregulated(P < 0.05) the lipogenic genes(FAS, LPL, SCD, ACCα) and myosin heavy-chain(MyHC)-IIa mRNA expression levels compared with the TS diet, but downregulated(P < 0.05) the CPT1 B and MyHC-IIb mRNA levels.Conclusions: In conclusion, these results provided compelling evidence that the different dietary starch source altered the carcass traits, meat flavor and quality in finishing pigs, and consumption of a diet with higher amylose/amylopectin ratio results in the production of a healthy, higher quality, and nutritional value pork. | Miao Yu Zhenming Li Ting Rong Gang Wang Zhichang Liu Weidong Chen Jiazhou Li Jianhao Li Xianyong Ma | 2021 | Journal of Animal Science and Biotechnology2021,12,1: | 13 |
| 5 | Marine Yeasts and Their Applications in Mariculture显示文摘The terrestrial yeasts have been receiving great attention in science and industry for over one hundred years because they can produce many kinds of bioactive substances. However, little is known about the bioactive substances of marine yeasts. In recent years, it has been found that marine yeasts have wide applications in mariculture and other fields. Therefore,marine yeasts, the bioactive substances from them and the applications of marine yeasts themselves and the bioactive substances they produced are reviewed in this paper. | CHI Zhenming LIU Zhiqiang GAO Lingmei GONG Fang MA Chunling WANG Xianghong LI Haifeng | 2006 | Journal of Ocean University of China2006,5,3: | 12 |
| 6 | Paleomagnetic results of Late Paleozoic rocks from northern Qiangtang Block in Qinghai-Tibet Plateau, China显示文摘Tectonic evolution of the Tethys and the boundary between the Gondwanaland and the Eurasia during the Carboniferous and Permian remain hotly debated. Qiangtang region in the Qinghai-Tibet Plateau may be a key place to study these problems. A paleomagnetic study was conducted on the Late Paleozoic rocks in the northern Qiangtang region (33.7°N, 86.7°W), Tibet. Two sites (21 samples) in the Upper Carboniferous, eleven sites (101 samples) in the Permian, and two sites (16 samples) in the Lower Triassic were investigated. The rock magnetic data revealed hematite and magnetite as the main magnetic carriers. In stepwise thermal demagnetization and/or combined alternating field (AC) demagnetization, two characteristic components in the majority of the samples were identified as (1) the Low-temperature Component (LTC), characterized by northerly decli- nation and moderate to steep inclination, corresponding to a pole position overlay with the present North Pole. A minority of the samples present single component, and their directions are the same as (2) the High-temperature Component (HTC) of double components. The combined single-component and HTC data of the Permian can pass the R-test at 95% level and the F-test at 99% level, as well as the BC-test. The pole position from the Late Carboniferous is at 31.8°S, 45.7°E with dp=2.1, dm=3.9, that from the Early and Middle (Late) Permian is at 31.7°S, 46.8°E with dp=9.2, dm=16.9 (34.4°N, 54.1°E with dp=6.9, dm=12.5) respectively, and that from the Early Triassic is at 16.9°S, 22.5°E with dp=4.9, dm=9.2. These pole positions are different from the other poles for the Qiangtang Block, which suggests the single-component and HTC directions are probably a primary magnetization and the northern Qiangtang Block was paleogeographically situated at low latitudes in the Northern Hemisphere in the Late Paleozoic. | CHENG Xin WU HanNing GUO Qiang HOU BaoNing XIA LingYan WANG HaiJun DIAO ZongBao HUO FeiFei JI WenHua LI RongShe CHEN ShouJian ZHAO ZhenMing LIU XiaoJi | 2012 | Science China Earth Sciences2012,55,1: | 9 |
| 7 | Paleomagnetic data from the Late Carboniferous-Late Permian rocks in eastern Tibet and their implications for tectonic evolution of the northern Qiangtang-Qamdo block显示文摘We report paleomagnetic results from the Late Carboniferous-Late Permian strata in eastern Tibet (China), and aim to clarify the tectonic and paleogeographic evolution of the northern Qiangtang-Qamdo block, which is the key to the study of plate boundary between the Gondwanaland and the Eurasia during the late Paleozoic. Two hundred and nineteen samples-including limestone, muddy siltstone, basalt, lava, and tuff-were collected at 24 sites in the Upper Carboniferous and Middle-Upper Permian successions. A systematic study of rock magnetism and paleomagnetism yields three reliable paleomagnetic pole positions. Both hematite and magnetite occurred in the Late Carboniferous limestone samples. The demagnetization curve shows a characteristic double-component, with the remanent magnetization (ChRM) exhibiting a positive polarity (negative inclination). In the Late Permian limestone, tuff, and basalt, magnetic information were recorded primarily in magnetite, although a small fraction of them was found in hematite in basalt. The demagnetization curve illustrates a double or single component, with the ChRM showing a negative polarity (positive inclination), which has passed the classic fold test successfully. The single polarity features of the ChRM directions of the Late Carboniferous and Middle-Late Permian rocks are respectively related to the Kiaman positive and reversed polarities under the stratigraphic coordinates. This, in turn, indicates that both ChRMs directions represent the original remanence directions. By comparison with the previously published paleomagnetic results from the late Paleozoic rocks in the northern Qiangtang Range, we suggest that: (1) Qamdo and northern Qiangtang block were independent of each other during the Late Carboniferous to the Early Permian periods. The north Lancangjiang ocean basin between the two blocks may have closed before the Middle Permian and been involved in the continent-continent collision stage in the Late Permian-Early Triassic periods. (2) The northern Qiangtang-Qamdo Block paleogeographically was situated at low to intermediate latitudes in the Southern Hemisphere in the Late Carboniferous-Late Permian periods, and began to displace northward in the Early Triassic, with an amount of more than 5000 km northward transport from its current location. | CHENG Xin WU HanNing DIAO ZongBao WANG HaiJun MA Lun ZHANG XiaoDong YANG Gang HONG JingJing JI WenHua LI RongShe CHEN ShouJian ZHAO ZhenMing | 2013 | Science China Earth Sciences2013,56,7: | 8 |
| 8 | Comparison of dilution effects of R134a and nitrogen on flammable hydrofluorocarbons显示文摘An experimental apparatus has been built to measure the flammability limits of combustible gases based on Chinesenational standard GB/T 12474-90. The flammability limits of four binary mixtures of R161/R134a,R152a/R134a, R161/N2 and R152a/N2 were measured with this apparatus at atmospheric pressure and ambienttemperature. The fuel inertization points (FIP) of these mixtures can be found from the envelopes. Comparisonswere made with the literature data; good agreement for most measurements was obtained. R134a was found tohave a better dilution effect than nitrogen in reducing the flammability of hydrofluorocarbons. | Zhenming Li Maoqiong Gong Jianfeng Wu Yuan Zhou | 2009 | Journal of Thermal Science2009,18,4: | 7 |
| 9 | Intermediate Spoofing Strategies and Countermeasures显示文摘Intermediate spoofing can impact most off-the-shelf Global Navigation Satellite Systems(GNSS)receivers,therefore low cost detection of such spoofing is very important to protect the reliability of the GNSS receivers used in critical safety and financial applications.This paper presents two strategies to analyze attacks by intermediate spoofing attackers to identify the weaknesses of such attacks.The analyses lead to a code and carrier phase consistency detection method with simulation results showing that this method can indicate the receiver when spoofing has occurred.The method can be used by most receivers,is inexpensive,and requires only a small software upgrade. | Yang Gao Hong Li Mingquan Lu Zhenming Feng | 2013 | Tsinghua Science and Technology2013,18,6: | 7 |
| 10 | A Rapid Analysis Tool for Aerodynamics/Aerothermodynamics of Hypersonic Vehicles显示文摘A rapid engineering surface panel method to analyze aerodynamics and aerothermodynamics of hypersonic vehicles is developed.To obtain the surface pressure distribution of a hypersonic vehicle,the local surface inclination method is applied to calculate the pressure coefficient for each surface panel element,of which the normal vector is corrected first by using an efficient data structure and Rey-casting algorithm,local Reynolds numbers are calculated according to the geometric streamline method,then the aerodynamic heating flux is computed by both reference enthalpy relations and Reynolds analogy method.Several typical test cases are performed and the results indicate that,the developed tool is effective in predicting the aerodynamics/aerothermodynamics for complex geometry of hypersonic vehicle in a wide range of Mach numbers with a sufficient accuracy. | Li Zhengzhou Xiao Tianhang Lü Fanxi Yu Xiongqing Zhang Zhenming Du Sha | 2017 | Transactions of Nanjing University of Aeronautics and Astronautics2017,34,4: | 7 |
| 11 | Tensile Properties and Deformation Behaviors of a New Aluminum Alloy for High Pressure Die Casting显示文摘Effects of natural aging and test temperature on the tensile behaviors have been studied for a highperformance cast aluminum alloy Al–10Si–1.2Cu–0.7Mn. Based on self-strengthening mechanism and spheroidization microstructures, the alloy tested at room temperature(RT) exhibits higher 0.2% proof stress(YS) of 206 MPa, ultimate tensile strength(UTS) of 331 MPa and elongation of 10%. Increasing aging time improves the YS and UTS and reduces the ductility of the alloy. Further increasing aging time beyond72 h does not signi?cantly increase the tensile strengths. Increasing test temperature signi?cantly decreases the tensile strengths and increases the ductility of the alloy. The UTS of the alloy can be estimated by using the hardness. The Portevin–Le Chatelier effect occurs at RT due to the interactions between solid solution atoms and dislocations. Similar behaviors occurring at 250 °C are attributed to dynamic strain aging mechanism. Increasing aging time leads to decrease in the strain-hardening exponent(n) value and increase in the strain-hardening coe?cient(k) value. Increasing test temperature apparently decreases the n and k values. Eutectic phase particles cracking and debonding determine the fracture mechanism of the alloy. Final failure of the alloy mainly depends on the global instability(high temperature, necking) and local instability(RT, shearing). Different tensile behaviors of the alloy are mainly attributed to different matrix strengths, phase particle strengths and damage rate. | Peng Zhang Zhenming Li Baoliang Liu Wenjiang Ding | 2017 | Journal of Materials Science & Technology2017,33,4: | 7 |
| 12 | Enhanced Carotenoid Production by a Mutant of the Marine Yeast Rhodotorula sp. hidai显示文摘After a serial of UV, EMS and NTG mutagenesis, a mutant named MM of the red marine yeast strain Rhodotorula sp. hidai was obtained. The mutant MM could produce 603.93 μg g-1 of carotenoid within 5 days in the medium containing 4.0 g sucrose, 1.5 g yeast extract, 0.1 g MgSO4, and 100 mL of sea water, with pH 6.0 and at 30 ℃, while only 213.18 μg g-1 of carotenoid was pro-duced by the wild type under the same conditions. | CONG Li, CHI Zhenming*, LI Jing, and WANG Xianghong UNESCO Chinese Center of Marine Biotechnology, Ocean University of China, Qingdao 266003, P. R. China | 2007 | Journal of Ocean University of China2007,6,1: | 6 |
| 13 | Amylase Production by the Marine Yeast Aureobasidium pullulans N13d显示文摘The marine yeast strain N13d, producing an extracellular amylase, was isolated from the deep sea sediments of the Pa-cific Ocean. This strain was identified to be Aureobasidium pullulans by 18S rRNA gene sequence analysis and routine yeast identi-fication methods. The optimal sea water medium for amylase production by this yeast strain was 1.0% peptone and 1.0% soluble starch with pH 4.0. The optimal conditions for amylase production by this yeast strain were with temperature 28 ℃, aeration rate 6 Lmin-1 and agitation speed 250 rmin-1. Under these conditions, 58.5 units of amylase activity per mg protein were produced within 56 h of fermentation. | LI Haifeng, CHI Zhenming *, WANG Xiaohong, and MA Chunling UNESCO Chinese Center of Marine Biotechnology, Ocean University of China, Qingdao 266003, P. R. China | 2007 | Journal of Ocean University of China2007,6,1: | 5 |
| 14 | Mitochondrial Genome of Episesarma lafondii(Brachyura:Sesarmidae)and Comparison with Other Sesarmid Crabs显示文摘Complete mitochondrial genomes(mitogenomes)can provide useful information for phylogenetic relationships,gene rearrangement,and molecular evolution.Here,the complete mitogenome of Episesarma lafondii(Brachyura:Grapsoidea:Sesarmidae)was sequenced through next-generation sequencing technique for the first time.The 15640 bp mitogenome contains the entire set of 37 genes and an AT-rich region.The rearrangements of two tRNA genes(tRNA-His and tRNA-Gln)are compared with that in the pancrustacean ground pattern,and the tandem duplication/random loss model was selected to explain the observed gene rearrangements.The phylogenetic results showed that all sesarmid crabs belong to the same group,wherein the genus Episesarma showed the closest relationship with Clistocoeloma.Furthermore,the monophyly of each family was well supported except for Xanthidae,Gecarcinidae,and Homolidae.The correlation between the phylogeny of Sesarmidae species and the gaps in the QIM region was analyzed.Evidently,the gaps between Q and I(Gap3 and between I and M(Gap4)degenerated with the evolution process.In general,the results will contribute to the in-depth understanding of gene rearrangements in Sesarmidae mitogenomes and provide new insights into the phylogeny of Brachyura. | ZHANG Ying GAO Yan GONG Li LU Xinting JIANG Lihua LIU Bingjian LIU Liqin LU Zhenming LI Pengfei | 2021 | Journal of Ocean University of China2021,20,6: | 4 |
| 15 | Analysis of Malware Application Based on Massive Network Traffic显示文摘Security and privacy issues are magnified by velocity, volume, and variety of big data. User's privacy is an even more sensitive topic attracting most people's attention. While XcodeGhost, a malware of i OS emerging in late 2015, leads to the privacy-leakage of a large number of users, only a few studies have examined XcodeGhost based on its source code. In this paper we describe observations by monitoring the network activities for more than 2.59 million i Phone users in a provincial area across 232 days. Our analysis reveals a number of interesting points. For example, we propose a decay model for the prevalence rate of Xcode Ghost and we find that the ratio of the infected devices is more than 60%; that a lot of popular applications, such as Wechat, railway 12306, didi taxi, Youku video are also infected; and that the duration as well as the traffic volume of most Xcode Ghost-related HTTP-requests is similar with usual HTTP-request which makes it difficult to be found. Besides, we propose a heuristic model based on fingerprint and its web-knowledge to identify the infected applications. The identifying result shows the efficiency of this model. | Xiaolin Gui Jun Liu Mucong Chi Chenyu Li Zhenming Lei | 2016 | China Communications2016,13,8: | 4 |
| 16 | Characterization of a Mutant of Alteromonas aurantia A18 and Its Application in Mariculture显示文摘Mutant J61321 with enhanced siderophore production of Alteromonas aurantia A18 was obtained after a series of chemical-physical mutageneses. It was found that the antibacterial activity against Vibrio anguillarum W-1 and siderophore produc- tion of the mutant were higher than those by the original strain A18 which had been used in mariculture. The results of the specific assay(Csáky and Arnow methods) of siderophore showed that the sidrophore with hydroxamate group was produced by mutant J61321 and the original strain A18, respectively, while the siderophore with catechol group was yielded by strain W-1 (Aibrio an- guillarum). Meanwhile, the siderophore yield, antibacterial activity and anti-chelator activity of strain J61321 were higher than those of its parent strain A18. | LI Junfeng CHI Zhenming LI Hongfang WANG Xianghong | 2008 | Journal of Ocean University of China2008,7,1: | 4 |
| 17 | Two-stage ADMM-based distributed optimal reactive power control method for wind farms considering wake effects显示文摘Since the connection of small-scale wind farms to distribution networks,power grid voltage stability has been reduced with increasing wind penetration in recent years,owing to the variable reactive power consumption of wind generators.In this study,a two-stage reactive power optimization method based on the alternating direction method of multipliers(ADMM)algorithm is proposed for achieving optimal reactive power dispatch in wind farm-integrated distribution systems.Unlike existing optimal reactive power control methods,the proposed method enables distributed reactive power flow optimization with a two-stage optimization structure.Furthermore,under the partition concept,the consensus protocol is not needed to solve the optimization problems.In this method,the influence of the wake effect of each wind turbine is also considered in the control design.Simulation results for a mid-voltage distribution system based on MATLAB verified the effectiveness of the proposed method. | Zhenming Li Zhao Xu Yawen Xie Donglian Qi Jianliang Zhang | 2021 | Global Energy Interconnection2021,4,3: | 3 |
| 18 | Optimum Production and Characterization of an Acid Protease from Marine Yeast Metschnikowia reukaufii W6b显示文摘The marine yeast strain W6b isolated from sediment of the South China Sea was found to produce a cell-bound acid protease.The crude acid protease produced by this marine yeast showed the highest activity at pH 3.5 and 40 ℃.The optimal pH and temperature for the crude acid protease were in agreement with those for acid protease produced by the terrestrial yeasts.The optimal medium of the acid protease production was seawater containing 1.0% glucose, 1.5% casein, and 0.5% yeast extract, and the optimal cultivation conditions of the acid protease production were pH 4.0, a temperature of 25 ℃ and a shaking speed of 140 rmin-1.Under the optimal conditions, 72.5 UmL-1 of acid protease activity could be obtained in cell suspension within 48 h of fermentation at shake flask level.The acid protease production was induced by high-molecular-weight nitrogen sources and repressed by low-molecu-lar-weight nitrogen sources.Skimmed-milk-clotting test showed that the crude acid protease from the cell suspension of the yeast W6b had high skimmed milk coagulability.The acid protease produced by M.reukaufii W6b may have highly potential applications in cheese, food and fermentation industries. | LI Jing PENG Ying WANG Xianghong CHI Zhenming | 2010 | Journal of Ocean University of China2010,9,4: | 3 |
| 19 | Electromagnetic Filtration of Primary Fe-Rich Phases from Al-Si Alloy Melt显示文摘Electromagnetic filtration of primary Fe-rich phases (complex compound of AlFeSiMn) from Al-Si alloy melt containing 1.2 wt pct Fe have been studied by theoretical analysis and on a self-designed electromagnetic filtration equipment. The principle of the electromagnetic filtration is that the EMF (electromagnetic force) scarcely acts on the primary Fe-rich phases having low electric conductivity, which are then moved in the direction opposite to that of the EMF. Experimental results show that the primary Fe-rich phases are separated from Al-Si alloy melt and are collected in the filter while the melt is in horizontal flow. The removal efficiency of the primary iron-phases (77) calculated is less as the greatest flow velocity of the melt (UM) and the height of the filter (2h) are larger, while it becomes larger as EMF, operating distance of electromagnetic force (cr) and particle size (dv) become larger. It has been confirmed that the primary iron-phases larger than 20 jim can be removed efficiently by theoretical analysis and experiments. This new technique is high efficient and available for continuously flowing melts as compared with natural settling and filtration methods, which offer a possibility for recycling high quality aluminum alloys. | Zhenming XU, Tianxiao LI, Da SHU and Yaohe ZHOU School of Materials Science and Engineering, Shanghai Jiaotong University, Shanghai 200030, China E-mail: zmxu@mail1.sjtu.edu.cn | 2001 | Journal of Materials Science & Technology2001,17,3: | 3 |
| 20 | Design and Analysis of the Gemini Chain System in Dual Clutch Transmission of Automobile显示文摘Chain drive system is widely used in the conditions of high-speed, overload, variable speed and load. Many studies are focused on the meshing theory and wear characteristics of chain drive system, but system design, analysis, and noise characteristics of the chain drive system are weak. System design and noise characteristic are studied for a new type Gemini chain of dual-clutch automatic transmission. Based on the meshing theory of silent chain, the design parameters of the Gemini chain system are calculated and the mathematical models and dynamic analysis models of the Gemini chain system are established. Dynamic characteristics of the Gemini chain system is simulated and the contact force of plate and pin, plate and sprockets, the chain tension forces, the transmission error and the stress of plates and pins are analyzed. According to the simulation results of the Gemini chain system, the noise experiment about system is carried out. The noise values are tested at different speed and load and spectral characteristics are analyzed. The results of simulation and experimental show that the contact forces of plate and pin, plate and sprockets are smaller than the allowable stress values, the chain tension force is less than ultimate tension and transmission error is limited in 1.2%. The noise values can meet the requirements of industrial design, and it is proved that the design and analysis method of the Gemini chain system is scientific and feasible. The design and test system is built from analysis to test of Gemini chain system. This research presented will provide a corresponding theoretical guidance for the design and dynamic characteristics and noise characteristics of chain drive system. | CHENG Yabing GUO Haitao FU Zhenming WAN Nen LI Lei WANG Yang | 2015 | Chinese Journal of Mechanical Engineering2015,28,1: | 3 |