Puncturing has been recognized as a promising technology to cope with the coexistence problem of enhanced mobile broadband(eMBB) and ultra-reliable low latency communications(URLLC)traffic. However, the steady perform...Puncturing has been recognized as a promising technology to cope with the coexistence problem of enhanced mobile broadband(eMBB) and ultra-reliable low latency communications(URLLC)traffic. However, the steady performance of eMBB traffic while meeting the requirements of URLLC traffic with puncturing is a major challenge in some realistic scenarios. In this paper, we pay attention to the timely and energy-efficient processing for eMBB traffic in the industrial Internet of Things(IIoT), where mobile edge computing(MEC) is employed for data processing. Specifically, the performance of eMBB traffic and URLLC traffic in a MEC-based IIoT system is ensured by setting the threshold of tolerable delay and outage probability, respectively. Furthermore,considering the limited energy supply, an energy minimization problem of eMBB device is formulated under the above constraints, by jointly optimizing the resource blocks(RBs) punctured by URLLC traffic, data offloading and transmit power of eMBB device. With Markov's inequality, the problem is reformulated by transforming the probabilistic outage constraint into a deterministic constraint. Meanwhile, an iterative energy minimization algorithm(IEMA) is proposed.Simulation results demonstrate that our algorithm has a significant reduction in the energy consumption for eMBB device and achieves a better overall effect compared to several benchmarks.展开更多
In many Chinese and American works,the differences of backgrounds,such as culture,customs and so on occupy a large part,through which readers can see the collision as well as coexistence between the two cultures.The J...In many Chinese and American works,the differences of backgrounds,such as culture,customs and so on occupy a large part,through which readers can see the collision as well as coexistence between the two cultures.The Joy Luck Club has no exception.In this work,the communication under different cultural backgrounds between the generations generates a lot of collision,but they get coexistence in the end.In this paper,the author will analyze the continuous collision and the final coexistence of the four pairs of mothers and daughters,so that readers can learn more about the differences between Chinese and American cultures.展开更多
On the basis of the characteristics of ancient Chinese culture,the paper discusses the formation inevitability of the 'Coexistence between Heaven and Man' building concept,the connection and the differences wi...On the basis of the characteristics of ancient Chinese culture,the paper discusses the formation inevitability of the 'Coexistence between Heaven and Man' building concept,the connection and the differences with the ecological concept of modern Chinese Vernacular Architecture.The key point is that the contemporary design should absorb the ancient Chinese culture of the 'Coexistence between Heaven and Man' building concept and the essence of Chinese Vernacular Architecture ecological concept,forming the design features of local ecology based on the environmental protection and harmonious coexistence.展开更多
As one of the best-known literary works of the American novelist Ursula K.Le Guin,The Left Hand of Darkness is not only successful in its splendid plots and beautiful language but also in the important function of its...As one of the best-known literary works of the American novelist Ursula K.Le Guin,The Left Hand of Darkness is not only successful in its splendid plots and beautiful language but also in the important function of its readers in reading.In the thesis,one of its themes,coexistence of opposites,is analyzed in the reader response perspective in order to reveal Le Guin's reader-consciousness.The theme exists on a higher level in the novel and expresses Le Guin's attitude towards life and universe.Le Guin unified her own philosophy in the novel and tried to call for the reader's resonance.展开更多
The coexistence theory of slag structure and it's application to calculation of the oxidizing capabilities of slag melts is described. It is shown that the law of mass action can be widely applied to the calculati...The coexistence theory of slag structure and it's application to calculation of the oxidizing capabilities of slag melts is described. It is shown that the law of mass action can be widely applied to the calculation of oxidizing capabilities of slag melts in combination with the coexistence theory of slag structure.For slag melts containing basic oxides FeO and MnO, their oxidizing capabilities can be expressed by N Fe tO =N FeO +6N Fe 2O 3 , while for slag melts containing basic oxides CaO, MgO, etc., in addition to FeO and MnO, their oxidizing capabilities can be given as N Fe tO =N FeO +6N Fe 2O 3 +8N Fe 3O 4 .展开更多
It is shown by the the law of mass action in combination with the coexistence theory of slag structure that KMn n =NMno /(NFeo [%Mn] does not change with basicities and maintains constant at constant temperature; the...It is shown by the the law of mass action in combination with the coexistence theory of slag structure that KMn n =NMno /(NFeo [%Mn] does not change with basicities and maintains constant at constant temperature; the oxidizing capabilities of multicomponent slag systems containing CaO, MgO etc., can be expressed by NFe tO =NFeO + 6NFe2 O3 + 8NFe3O4; the desulfurizing capabilities of various basic oxides for multicomponent slag systems can be calculated by Ls=8(KCaSNCaO+KMgsNMgo +KFeSNFeO)∑n/[%O]; the dephosphorizing capabili- ties of CaO-MgO-FeO-FeO O3-P2 O5 as well as CaO-FeO-Fe2 O3-A12 O3-P2 O5 molten slags expressed respectively by Lpo=(%P2O5)/[P]2 = 141.94[%O]5∑nK00(1 + K5N2Cao + K6N3CaO + K7N4CaO + K8N2MgO + K9N3MgO + K10N3FeO + K11N4Feo); LPO=(%P2O5)/[P]2= 141.94[%O]5∑nK00(1 + K10N2CaO+ K11N3CaO+ K12N4CaO + K13N3FeO + K14N4FeO) have good agreement with practical values.展开更多
Coexistence of attractors with striking characteristics is observed in this work, where a stable period-5 attractor coexists successively with chaotic band-ll, period-6, chaotic band-12 and band-6 attractors. They are...Coexistence of attractors with striking characteristics is observed in this work, where a stable period-5 attractor coexists successively with chaotic band-ll, period-6, chaotic band-12 and band-6 attractors. They are induced by dif- ferent mechanisms due to the interaction between the discontinuity and the non-invertibility. A characteristic boundary collision bifurcation, is observed. The critical conditions are obtained both analytically and numerically.展开更多
Based on the atomicity and molecularity as well as the consistency ofthermodynamic properties and activities of metallic melts with their structures, the coexistencetheory of metallic melts structure involving compoun...Based on the atomicity and molecularity as well as the consistency ofthermodynamic properties and activities of metallic melts with their structures, the coexistencetheory of metallic melts structure involving compound has been suggested. According to this theory,the calculating models of mass action concentrations for different binary metallic melts have beenformulated. The calculated mass action concentrations agree well with corresponding measuredactivities, which confirms that the suggested theory can reflect the structural characteristics ofmetallic melts involving compound and that the mass action law is widely applicable to this kind ofmetallic melts.展开更多
Leiomyomas are the most common benign tumors of the esophagus. They usually occur as a single lesion or as two or three nodules. Only two cases of esophageal multiple leiomyomas comprising more than 10 nodules have be...Leiomyomas are the most common benign tumors of the esophagus. They usually occur as a single lesion or as two or three nodules. Only two cases of esophageal multiple leiomyomas comprising more than 10 nodules have been reported previously. Moreover, there have been few reports of esophageal squamous cell carcinoma overlying submucosal tumors. We describe a 71-yearold man who was diagnosed as having a superficial esophageal cancer coexisting with two or three leiomyoma nodules. During surgery, 10 or more nodules that had not been evident preoperatively were palpable in the submucosal and muscular layers throughout the esophagus. As intramural metastasis of the esophageal cancer was suspected, we considered additional lymphadenectomy, but had to rule out this option because of the patient's severe anoxemia. Microscopic examination revealed that all the nodules were leiomyomas (20 lesions, up to 3 cm in diameter), and that invasion of the carcinoma cells was limited to the submucosal layer overlying a relatively large leiomyoma. This is the first report of superficial esophageal cancer coexisting with numerous solitary leiomyomas. Multiple minute leiomyomas are often misdiagnosed as intramural metastasis, and a leiomyoma at the base of a carcinoma lesion can also be rnisdiagnosed as tumor invasion. The present case shows that accurate diagnosis is required for the management of patients with coexisting superficial esophageal cancer and multiple leiomyomas.展开更多
This paper addresses the spectral coexistence between LEO constellation and GEO belt for global distributed earth stations. A specific method is introduced to mitigate the in-line interference by tilting the direction...This paper addresses the spectral coexistence between LEO constellation and GEO belt for global distributed earth stations. A specific method is introduced to mitigate the in-line interference by tilting the direction normal of phased array antennas of LEO satellites, and the optimal direction is found by solving a non-linear programming problem. The simulation results prove that the proposed approach leads to greater link availability while guaranteeing the desired received signal level especially for low-latitude earth stations.展开更多
Malignant gastrointestinal stromal tumors (GIST) are rare mesenchymal tumors originating from the wall of the gastrointestinal tract. Their coexistence with other tumors originating from other germ layers is unique....Malignant gastrointestinal stromal tumors (GIST) are rare mesenchymal tumors originating from the wall of the gastrointestinal tract. Their coexistence with other tumors originating from other germ layers is unique. We have reported a case of a 63-year-old GIST patient presenting as an epigastric mass associated with hepatic tumor. Histologically, the mesenteric tumor was composed of spindle cells showing both neural and smooth muscle differentiation. Immunohistochemical examination showed positive staining for CDl17, vimentin, S-100, and SMA, while CD34 antigen was negative. The hepatic tumor was diagnosed as hepatocellular carcinoma (HCC). To the best of our knowledge, this is the first case of GIST and HCC coexistence. The rarity of the case, however, should not lead to ignoring such a possibility in differential diagnosis.展开更多
The 3400-3600 MHz band is one of the most important candidate frequency bands for the rollout of 5 G system. However, the coexistence between 5 G system and fixed-satellite service(FSS) in this frequency band is one o...The 3400-3600 MHz band is one of the most important candidate frequency bands for the rollout of 5 G system. However, the coexistence between 5 G system and fixed-satellite service(FSS) in this frequency band is one of the most challenging problems for both academic researchers and industry engineers. In this paper, the saturation interference from 5 G base stations to the existing FSS above 3600 MHz is analyzed and the coexistence solution is achieved, which can reduce the interference and guarantee the coexistence between 5 G system and FSS. Furthermore, the Monte Carlo simulation, laboratory test and field test are carried out to verify the coexistence solution.Results show that an isolation distance of 1-2 km is required to avoid the saturation interference in terms of the adjacent bands scenario.To further reduce the isolation distance to 50 m, additional isolation of 35 dB will be necessary, which can be fulfilled by installing a filter at the input port of LNB from a real implementation perspective.展开更多
Formation and coexistence of tricalciurn silicate (C3S) and calcium sulphoaluminate ( C4 A3S^- ) minerals in Portland cement clinker containing calcium sulphoaluminate were investigated. Thef-CaO content, mineral ...Formation and coexistence of tricalciurn silicate (C3S) and calcium sulphoaluminate ( C4 A3S^- ) minerals in Portland cement clinker containing calcium sulphoaluminate were investigated. Thef-CaO content, mineral composite and formation of mineral in the clinker were analyzed respectively by chemical analysis, differential scanning calorimetry(DSC) and X-ray diffraction. The results show that, adding a suitable amount of BaO can improve the burnability of raw meal and promote the f-CaO absorption. Tricalcium silicate and calcium sulphoaluminate minerals can form and coexist in clinkers at 1 234-1 317 ℃ by the addition of BaO to the raw meal. A suitable amount of BaO expanded the coexistence temperature of two minerals by 58 ℃.展开更多
For the dense macro-femto coexistence networks scenario, a long-term-based handover(LTBH) algorithm is proposed. The handover decision algorithm is jointly determined by the angle of handover(AHO) and the time-tos...For the dense macro-femto coexistence networks scenario, a long-term-based handover(LTBH) algorithm is proposed. The handover decision algorithm is jointly determined by the angle of handover(AHO) and the time-tostay(TTS) to reduce the unnecessary handover numbers.First, the proposed AHO parameter is used to decrease the computation complexity in multiple candidate base stations(CBSs) scenario. Then, two types of TTS parameters are given for the fixed base stations and mobile base stations to make handover decisions among multiple CBSs. The simulation results show that the proposed LTBH algorithm can not only maintain the required transmission rate of users, but also effectively reduce the unnecessary numbers of handover in the dense macro-femto networks with the coexisting mobile BSs.展开更多
In this paper, to complete the global dynamics of a multi-strains SIS epidemic model, we establish a precise result on coexistence for the cases of the partial and complete duplicated multiple largest reproduction rat...In this paper, to complete the global dynamics of a multi-strains SIS epidemic model, we establish a precise result on coexistence for the cases of the partial and complete duplicated multiple largest reproduction ratios for this model.展开更多
The interference coexistence performance between the systems of a Long Term Evolution(LTE) network and Mobile Satellite Service(MSS) system,both of which work around the frequency of approximately 2 GHz according to t...The interference coexistence performance between the systems of a Long Term Evolution(LTE) network and Mobile Satellite Service(MSS) system,both of which work around the frequency of approximately 2 GHz according to the bandwidth allocation in China,is proposed in this article.The related background of an MSS system and the common terminologies are introduced.Further,the coexistence scenarios of different coverage situations shared by the two systems are discussed.The interference impact of an MSS transmission on an LTE system is evaluated using a specific Monte Carlo method.Finally,simulation results show that although no crucial issues for the coexistence of an LTE downlink and the MSS are observed,the LTE uplink suffers a considerable amount of interference from the MSS transmission.Given the insufficient isolation between LTE and MSS existing networks,and the rapid advance in the field of LTE,problems may emerge in the near future.Further,this article can be of significance in providing reference for frequency spectrum planning in the existing LTE networks.展开更多
Coexistence of satellite and terrestrial wireless communication systems in the same frequency band is quite promising for addressing the challenge of spectrum scarcity. To cope with the inevitable inter-system interfe...Coexistence of satellite and terrestrial wireless communication systems in the same frequency band is quite promising for addressing the challenge of spectrum scarcity. To cope with the inevitable inter-system interference, radio resource allocation at both sides should be carefully re-optimized. In this paper, we focus on a scenario where a satellite communication system and a terrestrial distributed antenna system(DAS) coexist via spectrum sharing. We particularly utilize the radio map(RM) to reduce the system overhead for channel acquisition. Based on the large-scale channel state information at the transmitter(CSIT), which is derived from the RM, we propose an optimized power allocation scheme to improve the achievable sum rate of the terrestrial system. For the satellite side, an opportunistic user scheduling scheme is presented, to reduce the harmful leakage interference to the terrestrial mobile users. Simulation results demonstrate that the proposed RM-based coordination scheme can significantly promote the performance of satellite terrestrial coexistence, although the small-scale channel fading has been ignored in the formulated optimization.展开更多
By using the latest geological,seismic,drilling and logging data,this article studies the basic conditions for the formation of the total petroleum system and the orderly coexisting characteristics and accumulation mo...By using the latest geological,seismic,drilling and logging data,this article studies the basic conditions for the formation of the total petroleum system and the orderly coexisting characteristics and accumulation models of conventional&unconventional reservoirs in the Lower Permian Fengcheng Formation in the Junggar Basin.Controlled by thermal evolution,hydrocarbon generation and expulsion process of the high-quality source rocks in alkaline lake as well as the characteristics of multi-type reservoirs(conglomerate,sandstone,dolomite and shale),conventional structure-lithologic reservoirs and tight oil and shale oil reservoirs controlled by source-reservoir structure have been formed.On the plane,mature conventional reservoirs,medium-high mature tight oil,and medium-high mature shale oil reservoirs coexist orderly from the slope area around Mahu sag to the sag.Based on the orderly coexisting characteristics of conventional and unconventional reservoirs in the Fengcheng Formation,it is clear that oil and gas in the Fengcheng Formation accumulate continuously over a large area in three accumulation models:integrated source-reservoir,source-reservoir in close contact,and separated source-reservoir model.The three accumulation models differ in relationship between source-reservoir structure,reservoir lithology and spatial distribution,hydrocarbon migration,oil and gas type.It is pointed out that the conventional&unconventional oil and gas should be explored and developed as a whole to achieve an overall breakthrough of the total petroleum system.This study is expected to enrich the geological theory of oil and gas enrichment in continental basins and to provide an analogy for exploration and research in other hydrocarbon-rich sags.展开更多
BACKGROUND The coexistence of meningioma and other intracranial primary benign tumors is rare,especially in non-neurofibromatosis type 2,and there is limited guidance for the management of such patients.Here,we report...BACKGROUND The coexistence of meningioma and other intracranial primary benign tumors is rare,especially in non-neurofibromatosis type 2,and there is limited guidance for the management of such patients.Here,we report a series of 5 patients with concomitant meningioma and other intracranial benign tumors,including subependymoma and pituitary adenoma.CASE SUMMARY Five non-neurofibromatosis type 2 patients with simultaneous occurrence of meningioma and other intracranial benign tumors were retrospectively reviewed.The patients had no history of previous irradiation.The clinical features,pre-and postoperative imaging,surgical procedure and pathological findings were extracted from electronic medical records.There were 4 female patients(80%)and 1 male patient(20%).The mean age was 42.8 years(range:29-52 years).The coexisting tumors included subependymoma in 1 case(20%)and pituitary adenoma in 4 cases(80%).The most common clinical symptom was headache(3/5,60%).Four patients(80%)underwent craniotomy.One patient(20%)underwent transsphenoidal surgery followed by transcranial operation.All tumor diagnoses were confirmed by histopathological examination.The mean follow-up was 38.8 mo(range:23-96 mo),and all 5 patients were in a stable condition at the last follow-up.CONCLUSION The simultaneous occurrence of meningioma and other intracranial benign tumors is a rare clinical event.Histological examination is necessary for the accurate diagnosis.Neurosurgeons should select the appropriate surgical strategy according to the clinical features of each patient,which may provide a more favorable prognosis for individual patients.展开更多
In this paper, the two-species prey-predator Lotka-Volterra model with the Holling's type III is discussed. By the method of coupled upper and lower solutions and its associated monotone iterations, the existence of ...In this paper, the two-species prey-predator Lotka-Volterra model with the Holling's type III is discussed. By the method of coupled upper and lower solutions and its associated monotone iterations, the existence of solutions for a strongly coupled elliptic system with homogeneous of Dirchlet boundary conditions is derived. These results show that this model admits at least one coexistence state if across-diffusions are weak.展开更多
基金supported by the Natural Science Foundation of China (No.62171051)。
文摘Puncturing has been recognized as a promising technology to cope with the coexistence problem of enhanced mobile broadband(eMBB) and ultra-reliable low latency communications(URLLC)traffic. However, the steady performance of eMBB traffic while meeting the requirements of URLLC traffic with puncturing is a major challenge in some realistic scenarios. In this paper, we pay attention to the timely and energy-efficient processing for eMBB traffic in the industrial Internet of Things(IIoT), where mobile edge computing(MEC) is employed for data processing. Specifically, the performance of eMBB traffic and URLLC traffic in a MEC-based IIoT system is ensured by setting the threshold of tolerable delay and outage probability, respectively. Furthermore,considering the limited energy supply, an energy minimization problem of eMBB device is formulated under the above constraints, by jointly optimizing the resource blocks(RBs) punctured by URLLC traffic, data offloading and transmit power of eMBB device. With Markov's inequality, the problem is reformulated by transforming the probabilistic outage constraint into a deterministic constraint. Meanwhile, an iterative energy minimization algorithm(IEMA) is proposed.Simulation results demonstrate that our algorithm has a significant reduction in the energy consumption for eMBB device and achieves a better overall effect compared to several benchmarks.
文摘In many Chinese and American works,the differences of backgrounds,such as culture,customs and so on occupy a large part,through which readers can see the collision as well as coexistence between the two cultures.The Joy Luck Club has no exception.In this work,the communication under different cultural backgrounds between the generations generates a lot of collision,but they get coexistence in the end.In this paper,the author will analyze the continuous collision and the final coexistence of the four pairs of mothers and daughters,so that readers can learn more about the differences between Chinese and American cultures.
文摘On the basis of the characteristics of ancient Chinese culture,the paper discusses the formation inevitability of the 'Coexistence between Heaven and Man' building concept,the connection and the differences with the ecological concept of modern Chinese Vernacular Architecture.The key point is that the contemporary design should absorb the ancient Chinese culture of the 'Coexistence between Heaven and Man' building concept and the essence of Chinese Vernacular Architecture ecological concept,forming the design features of local ecology based on the environmental protection and harmonious coexistence.
文摘As one of the best-known literary works of the American novelist Ursula K.Le Guin,The Left Hand of Darkness is not only successful in its splendid plots and beautiful language but also in the important function of its readers in reading.In the thesis,one of its themes,coexistence of opposites,is analyzed in the reader response perspective in order to reveal Le Guin's reader-consciousness.The theme exists on a higher level in the novel and expresses Le Guin's attitude towards life and universe.Le Guin unified her own philosophy in the novel and tried to call for the reader's resonance.
文摘The coexistence theory of slag structure and it's application to calculation of the oxidizing capabilities of slag melts is described. It is shown that the law of mass action can be widely applied to the calculation of oxidizing capabilities of slag melts in combination with the coexistence theory of slag structure.For slag melts containing basic oxides FeO and MnO, their oxidizing capabilities can be expressed by N Fe tO =N FeO +6N Fe 2O 3 , while for slag melts containing basic oxides CaO, MgO, etc., in addition to FeO and MnO, their oxidizing capabilities can be given as N Fe tO =N FeO +6N Fe 2O 3 +8N Fe 3O 4 .
文摘It is shown by the the law of mass action in combination with the coexistence theory of slag structure that KMn n =NMno /(NFeo [%Mn] does not change with basicities and maintains constant at constant temperature; the oxidizing capabilities of multicomponent slag systems containing CaO, MgO etc., can be expressed by NFe tO =NFeO + 6NFe2 O3 + 8NFe3O4; the desulfurizing capabilities of various basic oxides for multicomponent slag systems can be calculated by Ls=8(KCaSNCaO+KMgsNMgo +KFeSNFeO)∑n/[%O]; the dephosphorizing capabili- ties of CaO-MgO-FeO-FeO O3-P2 O5 as well as CaO-FeO-Fe2 O3-A12 O3-P2 O5 molten slags expressed respectively by Lpo=(%P2O5)/[P]2 = 141.94[%O]5∑nK00(1 + K5N2Cao + K6N3CaO + K7N4CaO + K8N2MgO + K9N3MgO + K10N3FeO + K11N4Feo); LPO=(%P2O5)/[P]2= 141.94[%O]5∑nK00(1 + K10N2CaO+ K11N3CaO+ K12N4CaO + K13N3FeO + K14N4FeO) have good agreement with practical values.
基金Project supported by the National Natural Science Foundation of China (Grant No 10275053)
文摘Coexistence of attractors with striking characteristics is observed in this work, where a stable period-5 attractor coexists successively with chaotic band-ll, period-6, chaotic band-12 and band-6 attractors. They are induced by dif- ferent mechanisms due to the interaction between the discontinuity and the non-invertibility. A characteristic boundary collision bifurcation, is observed. The critical conditions are obtained both analytically and numerically.
文摘Based on the atomicity and molecularity as well as the consistency ofthermodynamic properties and activities of metallic melts with their structures, the coexistencetheory of metallic melts structure involving compound has been suggested. According to this theory,the calculating models of mass action concentrations for different binary metallic melts have beenformulated. The calculated mass action concentrations agree well with corresponding measuredactivities, which confirms that the suggested theory can reflect the structural characteristics ofmetallic melts involving compound and that the mass action law is widely applicable to this kind ofmetallic melts.
文摘Leiomyomas are the most common benign tumors of the esophagus. They usually occur as a single lesion or as two or three nodules. Only two cases of esophageal multiple leiomyomas comprising more than 10 nodules have been reported previously. Moreover, there have been few reports of esophageal squamous cell carcinoma overlying submucosal tumors. We describe a 71-yearold man who was diagnosed as having a superficial esophageal cancer coexisting with two or three leiomyoma nodules. During surgery, 10 or more nodules that had not been evident preoperatively were palpable in the submucosal and muscular layers throughout the esophagus. As intramural metastasis of the esophageal cancer was suspected, we considered additional lymphadenectomy, but had to rule out this option because of the patient's severe anoxemia. Microscopic examination revealed that all the nodules were leiomyomas (20 lesions, up to 3 cm in diameter), and that invasion of the carcinoma cells was limited to the submucosal layer overlying a relatively large leiomyoma. This is the first report of superficial esophageal cancer coexisting with numerous solitary leiomyomas. Multiple minute leiomyomas are often misdiagnosed as intramural metastasis, and a leiomyoma at the base of a carcinoma lesion can also be rnisdiagnosed as tumor invasion. The present case shows that accurate diagnosis is required for the management of patients with coexisting superficial esophageal cancer and multiple leiomyomas.
基金supported by the National Natural Science Foundation of China (grant no. 91738101 and 91438206)
文摘This paper addresses the spectral coexistence between LEO constellation and GEO belt for global distributed earth stations. A specific method is introduced to mitigate the in-line interference by tilting the direction normal of phased array antennas of LEO satellites, and the optimal direction is found by solving a non-linear programming problem. The simulation results prove that the proposed approach leads to greater link availability while guaranteeing the desired received signal level especially for low-latitude earth stations.
文摘Malignant gastrointestinal stromal tumors (GIST) are rare mesenchymal tumors originating from the wall of the gastrointestinal tract. Their coexistence with other tumors originating from other germ layers is unique. We have reported a case of a 63-year-old GIST patient presenting as an epigastric mass associated with hepatic tumor. Histologically, the mesenteric tumor was composed of spindle cells showing both neural and smooth muscle differentiation. Immunohistochemical examination showed positive staining for CDl17, vimentin, S-100, and SMA, while CD34 antigen was negative. The hepatic tumor was diagnosed as hepatocellular carcinoma (HCC). To the best of our knowledge, this is the first case of GIST and HCC coexistence. The rarity of the case, however, should not lead to ignoring such a possibility in differential diagnosis.
基金partly supported by National Natural Science Foundation of China (NSFC) (Grant No. 61525101, 61631003)
文摘The 3400-3600 MHz band is one of the most important candidate frequency bands for the rollout of 5 G system. However, the coexistence between 5 G system and fixed-satellite service(FSS) in this frequency band is one of the most challenging problems for both academic researchers and industry engineers. In this paper, the saturation interference from 5 G base stations to the existing FSS above 3600 MHz is analyzed and the coexistence solution is achieved, which can reduce the interference and guarantee the coexistence between 5 G system and FSS. Furthermore, the Monte Carlo simulation, laboratory test and field test are carried out to verify the coexistence solution.Results show that an isolation distance of 1-2 km is required to avoid the saturation interference in terms of the adjacent bands scenario.To further reduce the isolation distance to 50 m, additional isolation of 35 dB will be necessary, which can be fulfilled by installing a filter at the input port of LNB from a real implementation perspective.
基金Funded by the National Basic Research Program of China (No.2009CB623100)National Eleven Five-Year Scientific and Technical Support Plans (No. 2006BAF02A24)+2 种基金the Natural Science Fund for Colleges and Universities in Jiangsu Province(No. 08KJB430006)the Open Fund for the Key Laboratory of Inorganical and Composite Materials in Jiangsu Province(No.wjjqfhxc1200801)the Innovation Fund of Doctoral Dissertation of Nanjing University of Technology (No. BSCX200705)
文摘Formation and coexistence of tricalciurn silicate (C3S) and calcium sulphoaluminate ( C4 A3S^- ) minerals in Portland cement clinker containing calcium sulphoaluminate were investigated. Thef-CaO content, mineral composite and formation of mineral in the clinker were analyzed respectively by chemical analysis, differential scanning calorimetry(DSC) and X-ray diffraction. The results show that, adding a suitable amount of BaO can improve the burnability of raw meal and promote the f-CaO absorption. Tricalcium silicate and calcium sulphoaluminate minerals can form and coexist in clinkers at 1 234-1 317 ℃ by the addition of BaO to the raw meal. A suitable amount of BaO expanded the coexistence temperature of two minerals by 58 ℃.
基金The National Natural Science Foundation of China(No.61471164)the Fundamental Research Funds for the Central Universitiesthe Scientific Innovation Research of College Graduates in Jiangsu Province(No.KYLX-0133)
文摘For the dense macro-femto coexistence networks scenario, a long-term-based handover(LTBH) algorithm is proposed. The handover decision algorithm is jointly determined by the angle of handover(AHO) and the time-tostay(TTS) to reduce the unnecessary handover numbers.First, the proposed AHO parameter is used to decrease the computation complexity in multiple candidate base stations(CBSs) scenario. Then, two types of TTS parameters are given for the fixed base stations and mobile base stations to make handover decisions among multiple CBSs. The simulation results show that the proposed LTBH algorithm can not only maintain the required transmission rate of users, but also effectively reduce the unnecessary numbers of handover in the dense macro-femto networks with the coexisting mobile BSs.
文摘In this paper, to complete the global dynamics of a multi-strains SIS epidemic model, we establish a precise result on coexistence for the cases of the partial and complete duplicated multiple largest reproduction ratios for this model.
文摘The interference coexistence performance between the systems of a Long Term Evolution(LTE) network and Mobile Satellite Service(MSS) system,both of which work around the frequency of approximately 2 GHz according to the bandwidth allocation in China,is proposed in this article.The related background of an MSS system and the common terminologies are introduced.Further,the coexistence scenarios of different coverage situations shared by the two systems are discussed.The interference impact of an MSS transmission on an LTE system is evaluated using a specific Monte Carlo method.Finally,simulation results show that although no crucial issues for the coexistence of an LTE downlink and the MSS are observed,the LTE uplink suffers a considerable amount of interference from the MSS transmission.Given the insufficient isolation between LTE and MSS existing networks,and the rapid advance in the field of LTE,problems may emerge in the near future.Further,this article can be of significance in providing reference for frequency spectrum planning in the existing LTE networks.
基金supported in part by the National Science Foundation of China under grant No.61701457
文摘Coexistence of satellite and terrestrial wireless communication systems in the same frequency band is quite promising for addressing the challenge of spectrum scarcity. To cope with the inevitable inter-system interference, radio resource allocation at both sides should be carefully re-optimized. In this paper, we focus on a scenario where a satellite communication system and a terrestrial distributed antenna system(DAS) coexist via spectrum sharing. We particularly utilize the radio map(RM) to reduce the system overhead for channel acquisition. Based on the large-scale channel state information at the transmitter(CSIT), which is derived from the RM, we propose an optimized power allocation scheme to improve the achievable sum rate of the terrestrial system. For the satellite side, an opportunistic user scheduling scheme is presented, to reduce the harmful leakage interference to the terrestrial mobile users. Simulation results demonstrate that the proposed RM-based coordination scheme can significantly promote the performance of satellite terrestrial coexistence, although the small-scale channel fading has been ignored in the formulated optimization.
基金Supported by the China National Science and Technology Major Project(2017ZX05001-004,2016ZX05046-006)Petrochina Science and Technology Major Project(2019E-2601,2019E-2602)。
文摘By using the latest geological,seismic,drilling and logging data,this article studies the basic conditions for the formation of the total petroleum system and the orderly coexisting characteristics and accumulation models of conventional&unconventional reservoirs in the Lower Permian Fengcheng Formation in the Junggar Basin.Controlled by thermal evolution,hydrocarbon generation and expulsion process of the high-quality source rocks in alkaline lake as well as the characteristics of multi-type reservoirs(conglomerate,sandstone,dolomite and shale),conventional structure-lithologic reservoirs and tight oil and shale oil reservoirs controlled by source-reservoir structure have been formed.On the plane,mature conventional reservoirs,medium-high mature tight oil,and medium-high mature shale oil reservoirs coexist orderly from the slope area around Mahu sag to the sag.Based on the orderly coexisting characteristics of conventional and unconventional reservoirs in the Fengcheng Formation,it is clear that oil and gas in the Fengcheng Formation accumulate continuously over a large area in three accumulation models:integrated source-reservoir,source-reservoir in close contact,and separated source-reservoir model.The three accumulation models differ in relationship between source-reservoir structure,reservoir lithology and spatial distribution,hydrocarbon migration,oil and gas type.It is pointed out that the conventional&unconventional oil and gas should be explored and developed as a whole to achieve an overall breakthrough of the total petroleum system.This study is expected to enrich the geological theory of oil and gas enrichment in continental basins and to provide an analogy for exploration and research in other hydrocarbon-rich sags.
基金Supported by the LiaoNing Revitalization Talents Program,No.XLYC1807253the National Natural Science Foundation of China,No.81772653。
文摘BACKGROUND The coexistence of meningioma and other intracranial primary benign tumors is rare,especially in non-neurofibromatosis type 2,and there is limited guidance for the management of such patients.Here,we report a series of 5 patients with concomitant meningioma and other intracranial benign tumors,including subependymoma and pituitary adenoma.CASE SUMMARY Five non-neurofibromatosis type 2 patients with simultaneous occurrence of meningioma and other intracranial benign tumors were retrospectively reviewed.The patients had no history of previous irradiation.The clinical features,pre-and postoperative imaging,surgical procedure and pathological findings were extracted from electronic medical records.There were 4 female patients(80%)and 1 male patient(20%).The mean age was 42.8 years(range:29-52 years).The coexisting tumors included subependymoma in 1 case(20%)and pituitary adenoma in 4 cases(80%).The most common clinical symptom was headache(3/5,60%).Four patients(80%)underwent craniotomy.One patient(20%)underwent transsphenoidal surgery followed by transcranial operation.All tumor diagnoses were confirmed by histopathological examination.The mean follow-up was 38.8 mo(range:23-96 mo),and all 5 patients were in a stable condition at the last follow-up.CONCLUSION The simultaneous occurrence of meningioma and other intracranial benign tumors is a rare clinical event.Histological examination is necessary for the accurate diagnosis.Neurosurgeons should select the appropriate surgical strategy according to the clinical features of each patient,which may provide a more favorable prognosis for individual patients.
基金Supported by the National Natural Science Foundation of China(1057601310871075)
文摘In this paper, the two-species prey-predator Lotka-Volterra model with the Holling's type III is discussed. By the method of coupled upper and lower solutions and its associated monotone iterations, the existence of solutions for a strongly coupled elliptic system with homogeneous of Dirchlet boundary conditions is derived. These results show that this model admits at least one coexistence state if across-diffusions are weak.